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Sample records for nutrient solution concentrations

  1. The effect of growing media and concentration of nutrient solution on growth, flowering and macroelement content of media and leaves of Tymophylla tenuiloba Small

    Directory of Open Access Journals (Sweden)

    Joanna Nowak

    2013-12-01

    Full Text Available Effects of growing media and concentration of nutrient solution on growth, flowering, evapotranspiration and macroelement content of media and leaves of Tymophylla tenuiloba were evaluated under ebb-and-flow conditions. Two media: peat and peat + perlite (3:l, v/v, and four concentrations of nutrient solution: 1.0, 1.5, 2.0, 2.5 mS cm-1 were applied. High quality plants were produced in both media and all concentration of nutrient solution. The lowest evapotranspiration was measured at the highest concentration of nutrient solution. N concentration of leaves was high in all treatments. Concentrations of K, Ca, and Mg decreased with increasing concentration of nutrient solution. Opposite was found for P. At the end of cultivation the lowest pH was measured in the upper layer of growing media. The highest total soluble salt level was measured in the upper layers. Upper layers accumulated more N-NO3, P, Ca, and Mg. Mineral element content of both media was high in all concentrations of nutrient solution. Low concentration of nutrient solution at 1.0 mS cm-1 is recommended, although -1Tymophylla tenuiloba-1 can be also cultivated at higher concentrations of nutrient solution up to 2.5mS cm-1, if placed on the same bench with other bedding plants requiring more nutrients.

  2. Influence of drainage and nutrient-solution nitrogen and potassium concentrations on the agronomic behavior of bell-pepper plants cultivated in a substrate.

    Science.gov (United States)

    Wamser, Anderson Fernando; Cecilio Filho, Arthur Bernardes; Nowaki, Rodrigo Hiyoshi Dalmazzo; Mendoza-Cortez, Juan Waldir; Urrestarazu, Miguel

    2017-01-01

    The interactive effects of N (6, 9, 12 and 15 mmol L-1) and K (3, 5, 7, and 9 mmol L-1) concentrations in nutrient solutions were evaluated on bell pepper grown in a coconut-coir substrate and fertilized without drainage. An additional treatment with drainage was evaluated using N and K concentrations of 12 and 7 mmol L-1, respectively. The hybrid Eppo cultivar of yellow bell pepper was cultivated for 252 days beginning 9 November 2012. Electrical conductivity (EC), the N and K concentrations in the substrate solution, marketable fruit yield, total dry weight and macronutrient concentrations in shoots were periodically evaluated. Fruit production was lower in the system without drainage, regardless of the N and K concentrations, compared to the recommended 10-20% drainage of the volume of nutrient solution applied. Higher K concentrations in the nutrient solution did not affect plant production in the system without drainage for the substrate with an initial K concentration of 331.3 mg L-1. Fruit yield was higher without drainage at a nutrient-solution N concentration of 10.7 mmol L-1. The upper EC limit of the substrate solution in the system without drainage was exceeded 181 days after planting. Either lower nutrient concentrations in the nutrient solution or a drainage system could thus control the EC in the substrate solution.

  3. Nitrogen and potassium concentrations in the nutrients solution for melon plants growing in coconut fiber without drainage.

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    Gratieri, Luiz Augusto; Cecílio Filho, Arthur Bernardes; Barbosa, José Carlos; Pavani, Luiz Carlos

    2013-01-01

    With the objective of evaluating the effects of N and K concentrations for melon plants, an experiment was carried out from July 1, 2011 to January 3, 2012 in Muzambinho city, Minas Gerais State, Brazil. The "Bonus no. 2" was cultivated at the spacing of 1.1 × 0.4. The experimental design was a randomized complete block with three replications in a 4 × 4 factorial scheme with four N concentrations (8, 12, 16, and 20 mmol L(-1)) and four K concentrations (4, 6, 8, and 10 mmol L(-1)). The experimental plot constituted of eight plants. It was observed that the leaf levels of N and K, of N-NO₃ and of K, and the electrical conductivity (CE) of the substrate increased with the increment of N and K in the nutrients' solution. Substratum pH, in general, was reduced with increments in N concentration and increased with increasing K concentrations in the nutrients' solution. Leaf area increased with increments in N concentration in the nutrients solution. Fertigation with solutions stronger in N (20 mmol L(-1)) and K (10 mmol L(-1)) resulted in higher masses for the first (968 g) and the second (951 g) fruits and crop yield (4,425 gm(-2)).

  4. Nitrogen and Potassium Concentrations in the Nutrients Solution for Melon Plants Growing in Coconut Fiber without Drainage

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    Luiz Augusto Gratieri

    2013-01-01

    Full Text Available With the objective of evaluating the effects of N and K concentrations for melon plants, an experiment was carried out from July 1, 2011 to January 3, 2012 in Muzambinho city, Minas Gerais State, Brazil. The “Bonus no. 2” was cultivated at the spacing of 1.1 × 0.4. The experimental design was a randomized complete block with three replications in a 4 × 4 factorial scheme with four N concentrations (8, 12, 16, and 20 mmol L−1 and four K concentrations (4, 6, 8, and 10 mmol L−1. The experimental plot constituted of eight plants. It was observed that the leaf levels of N and K, of N-NO3 and of K, and the electrical conductivity (CE of the substrate increased with the increment of N and K in the nutrients' solution. Substratum pH, in general, was reduced with increments in N concentration and increased with increasing K concentrations in the nutrients' solution. Leaf area increased with increments in N concentration in the nutrients solution. Fertigation with solutions stronger in N (20 mmol L−1 and K (10 mmol L−1 resulted in higher masses for the first (968 g and the second (951 g fruits and crop yield (4,425 gm−2.

  5. The Effect of Potassium Concentration in Nutrient Solution on Lycopene, Vitamin C and Qualitative Characteristics of Cherry Tomato in Saline Conditions

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    E. Shabani Sangtarashani

    2013-06-01

    Full Text Available Potassium (K has a special place in improving the quality of agricultural products. To evaluate the effect of K concentration in nutrient solution on lycopene content, vitamin C and qualitative characteristics of cherry tomato in NaCl salinity conditions, an experiment was carried out as a completely randomized design with five treatments and three replications at university of Tabriz, Tabriz, Iran, in 2010. Treatments consisted of four concentrations of K (0.2, 2, 7 and 14 mM in nutrient solution with 60 mM NaCl concentration. A nutrient solution treatment without salinity was considered as control. The experiment was conducted in greenhouse, in a hydroponic system. The results indicated that increasing of K concentration increased lycopene content in fruit. Lycopene content in control treatment showed significant difference (P<0.01 in comparison with salinity treatments. With increasing the K concentration (except at 14 mM concentration, vitamin C content was increased, but indicated no statistically significant difference. Vitamin C content in saline conditions was more than control treatment, but showed no significant difference. Adding potassium concentration in nutrient solution improved yield and enhanced quality parameters such as percentage of dry matter, soluble solids and electrical conductivity of fruit extract. Since in saline conditions, the qualitative characteristics of tomato at 7 mM concentration were in the best situation, therefore using this concentration is recommended.

  6. Response of non-added solutes during nutrient addition experiments in streams

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    Rodriguez-Cardona, B.; Wymore, A.; Koenig, L.; Coble, A. A.; McDowell, W. H.

    2015-12-01

    Nutrient addition experiments, such as Tracer Additions for Spiraling Curve Characterization (TASCC), have become widely popular as a means to study nutrient uptake dynamics in stream ecosystems. However, the impact of these additions on ambient concentrations of non-added solutes is often overlooked. TASCC addition experiments are ideal for assessing interactions among solutes because it allows for the characterization of multiple solute concentrations across a broad range of added nutrient concentrations. TASCC additions also require the addition of a conservative tracer (NaCl) to track changes in conductivity during the experimental manipulation. Despite its use as a conservative tracer, chloride (Cl) and its associated sodium (Na) might change the concentrations of other ions and non-added nutrients through ion exchange or other processes. Similarly, additions of biologically active solutes might change the concentrations of other non-added solutes. These methodological issues in nutrient addition experiments have been poorly addressed in the literature. Here we examine the response of non-added solutes to pulse additions (i.e. TASCC) of NaCl plus nitrate (NO3-), ammonium, and phosphate across biomes including temperate and tropical forests, and arctic taiga. Preliminary results demonstrate that non-added solutes respond to changes in the concentration of these added nutrients. For example, concentrations of dissolved organic nitrogen (DON) in suburban headwater streams of New Hampshire both increase and decrease in response to NO3- additions, apparently due to biotic processes. Similarly, cations such as potassium, magnesium, and calcium also increase during TASCC experiments, likely due to cation exchange processes associated with Na addition. The response of non-added solutes to short-term pulses of added nutrients and tracers needs to be carefully assessed to ensure that nutrient uptake metrics are accurate, and to detect biotic interactions that may

  7. Gamma radiation and osmotic potential of the nutrient solution differentially affect macronutrient concentrations, pH and EC in chilhuacle pepper fruits

    International Nuclear Information System (INIS)

    Victor Garcia-Gaytan, Libia Iris Trejo-Tellez; Olga Tejeda-Sartorius; Maribel Ramirez-Martinez; Julian Delgadillo-Martinez; Fernando Carlos Gomez-Merino; Soledad Garcia-Morales

    2018-01-01

    Chilhuacle pepper (Capsicum annuum L.) seeds were exposed to gamma radiation (GR) doses (0, 10, 80 and 120 Gy), and plants were grown in hydroponics with different osmotic potentials (OP) (- 0.036, - 0.072, - 0.092, and - 0.108 MPa) in the nutrient solution. We measured the nutrient concentrations, pH and electrical conductivity (EC) in fruits at different time points after transplanting (70, 90 and 130 dat), and found the GR, nutrient solution OP and their interactions differentially affected N, P, K, Ca, and Mg concentrations, as well as pH and EC in chilhuacle peppers. (author)

  8. Tomato root growth and phosphorus absorption kinetics by tomato plants as affected by phosphorus concentration in nutrient solution

    International Nuclear Information System (INIS)

    Fontes, P.C.R.; Barber, S.A.

    1984-01-01

    To evaluate the effects P concentrations in nutrient solution on root growth and on root physiological characteristics involved in P uptake by tomato Lycopersicon esculentum Mill plants, six seedlings were grown in nutrient solution at initial concentrations of 48.5, 97, 194 and 388 μMP until one day before harvest. They were then transferred to solutions with P at 20 μM and 30 μM, and the depletion curves and Michaelis-Menten parameters were determined. The conclusions were that as P supply increased and as the plant P contents are sufficient for maximum growth, the rate of P uptake tends to be lower. The results also indicate that total P uptake by tomato seedlings depends on the amount of root surface area exposed to P. (M.A.C.) [pt

  9. Effect of organic substrates on available elemental contents in nutrient solution

    Energy Technology Data Exchange (ETDEWEB)

    Ao, Y.S.; Sun, M.; Li, Y.Q. [Shanghai Jiao Tong University, Shanghai (China). School for Agriculture & Biology

    2008-07-15

    In this paper, the changes of available elemental contents in the nutrient solution extracts of organic substrates (peat moss, charred rice husk, chicken manure, sawdust, turfgrass clipping and weathered coal) were studied and compared with that in the water extracts. Results showed that available elemental contents in the nutrient solution extracts are significantly different between organic substrates, whereas ionic concentrations are basically under steady condition after treatment for 36-108 h. Ionic contents in the nutrient solution extracts are not equal to the value of adding ionic concentrations in the supplied nutrient solution to that in the water extract. Thus, a mathematical model was proposed for adjusting the composition of supplied nutrient solution to match plant requirements in the organic soilless culture system.

  10. Production of gherkin seedlings in coconut fiber fertirrigated with different nutrient solutions

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    Francisco de Assis de Oliveira

    Full Text Available ABSTRACT Seedling quality is a key factor to achieve success in vegetable production. The present work aimed to evaluate the production of gherkin seedlings in substrate of coconut fiber fertirrigated with different concentrations of nutrients. The experimental design was completely randomized in a 3 × 5 factorial with four replications. The treatments consisted of combinations of three cultivars of gherkin (Do Norte, Liso de Calcutá, e Liso Gibão with five concentrations of nutrients in the solution (0, 25, 50, 75, and 100%. The nutrient solution, considered standard, matches the recommended solution for melon in hydroponic systems. We evaluated the variables: chlorophyll index, shoot length, number of leaves, stem diameter, main root length, dry weight of leaves, roots, and stem, mass of total dry matter, leaf area, specific leaf area, and leaf area ratio. All variables were affected by the ionic concentration in nutrient solutions. The use of coconut fiber in the production of gherkin seedlings is more efficient with nutrient solutions in concentrations ranging from 75 to 100% of the recommended solution for melon cultivation.

  11. Effect of Nitrogen Form and pH of Nutrient Solution on the Shoot Concentration of Phosphorus, Nitrate, and Nitrogen of Spinach in Hydroponic Culture

    OpenAIRE

    N. Najafi; M. Parsazadeh

    2010-01-01

    In order to study the effect of nitrogen form and pH of nutrient solution on the shoot concentration of P, nitrate, organic N + inorganic ammonium, and total N of spinach, a factorial experiment was conducted with two factors including pH of nutrient solution in three levels (4.5, 6.5 and 8.0) and nitrate to ammonium ratio of nutrient solution in five levels (100:0, 75:25, 50:50, 25:75 and 0:100). This factorial experiment was carried out in a completely randomized design with four replicatio...

  12. Effect of Nutrient Solution Concentration, Time and Frequency of Foliar Application on Growth of Leaf and Daughter Corms of Saffron (Crocus sativus L.

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    R Khorasani

    2015-07-01

    Full Text Available In order to investigate the effect of different levels of nutrient solution concentration and times and frequencies of foliar applications on dry weight, nitrogen, phosphorus and potassium concentrations of leaf and corm of saffron, a pot experiment was conducted as a completely randomized design with factorial arrangement and three replications under open door conditions in research garden of ferdowsi university, faculty of agriculture. The experimental treatments were included 4 levels of solution concentration (0, 4, 8 and 12 per 1000 and 7 levels of time and frequency of foliar applications (F1: foliar application on 3th February, F2: foliar application on 18th February, F3: foliar application on 5th March, F4: foliar applications on 3th and 18th February, F5: foliar applications on 3th February and 5th March, F6: foliar applications on 18th February and 5th March, F7: foliar applications on 3th and 18th February and 5th March. Results of variance analysis showed that fresh and dry weight of corm and leaf were not influenced by concentration, time and frequency of foliar applications. Also, comparison of nitrogen, phosphorus and potassium concentrations of leaf and corm showed that there was no significant difference between levels of foliar treatments and control. Therefore, it seems that due attention to pattern of leaf and low nutrient demand of saffron, foliar applications in different levels of nutrient solution concentrations and times and frequencies of foliar applications could not increase vegetative growth and consequently, could not improve the growth and nutritional properties of saffron corms.

  13. Deciphering relationships between in-stream travel times, nutrient concentrations, and uptake through analysis of hysteretic and non-hysteretic kinetic behavior

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    Covino, T. P.; Bowden, W. B.; Gooseff, M. N.; Wollheim, W. M.; McGlynn, B. L.; Whittinghill, K. A.; Wlostowski, A. N.; Herstand, M. R.

    2012-12-01

    Understanding the relationship between solute travel time, concentration, and nutrient uptake remains a central question in watershed hydrology and biogeochemistry. Theoretical understanding predicts that nutrient uptake should increase as in-stream solute travel time lengthens and/or as concentration increases; however, results from field-based studies have been contradictory. We used a newly developed approach, Tracer Additions for Spiraling Curve Characterization (TASCC), to investigate relationships between solute travel time, nutrient concentration, and nutrient uptake across a range of stream types. This approach allows us to quantify in-stream nutrient uptake across a range of travel times and nutrient concentrations using single instantaneous injections (slugs) of conservative and non-conservative tracers. In some systems we observed counter-clockwise hysteresis loops in the relationship between nutrient uptake and concentration. Greater nutrient uptake on the falling limb of tracer breakthrough curves indicates stronger uptake for a given concentration at longer travel times. However, in other systems we did not observe hysteresis in these relationships. Lack of hysteresis indicates that nutrient uptake kinetics were not influenced by travel time travel time. Here we investigate the potential roles of travel time and in-stream flowpaths that could be responsible for hysteretic behavior.

  14. Heavy metal toxicities in vegetable crops. VI. The effect of potassium and calcium concentration in the nutrient solution on manganese toxicities in vegetable crops

    Energy Technology Data Exchange (ETDEWEB)

    Osawa, T; Ikeda, H

    1977-01-01

    Eight species of vegetable crops were grown in solution culture in order to investigate the effect of potassium and calcium concentration in the nutrient solution on manganese toxicities in vegetable crops. Manganese was supplied at levels of 0.5, 30, and 100 ppm. At each manganese level potassium or calcium was supplied at rates of 2, 6, and 18 me/l. The pH of the nutrient solution was adjusted to 5. Manganese excess induced interveinal chlorosis on upper leaves in bean, eggplant, pepper, and spinach, and marginal chlorosis on lower leaves in cabbage, lettuce, and celery. In Welsh onions chlorosis was induced on lower leaves. Increasing the supply of potassium and calcium reduced the severity of manganese-induced chlorosis. This beneficial effect was generally more marked with calcium than with potassium. Increasing the supply of potassium and calcium was effective in alleviating the growth reduction of vegetable crops due to manganese excess. This effect also was more marked with calcium than with potassium. With increasing manganese level in the nutrient solution the manganese concentration in leaves of vegetable crops increased. Increasing the supply of potassium and calcium inhibited excessive accumulation of manganese in leaves. The influence of calcium was stronger than that of potassium. In any of the vegetable crops tested, regardless of potassium and calcium treatments, manganese concentration in leaves was closely related to manganese toxicities; the more the accumulation of manganese in leaves increased, the more the severity of manganese-induced chlorosis and growth reduction increased.

  15. Experimental analysis of an effect of the nutrient type and its concentration on the rheological properties of the baker’s yeast suspensions

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    Major-Godlewska Marta

    2015-09-01

    Full Text Available The aim of the study presented was to experimentally analyze an effect of the nutrient type and its concentration on the variability of rheological properties of the baker’s yeast suspensions for different time periods. Aqueous suspensions of the baker’s yeast of various concentration (solution I, without nutrient and yeasts suspended in aqueous solution of sucrose or honey as nutrients with different concentration (solution II or solution III were tested. Experiments were carried out using rotational rheoviscometer of type RT10 by a company HAAKE. The measurements were conducted for different time periods (from 1 h up to 144 h at given fluid temperature. On the basis of the obtained data, rheological characteristics of the aqueous solution of baker’s yeast suspensions without and with nutrients of different sucrose or honey concentration were identified and mathematically described.

  16. Effect of phosphorus concentration of the nutrient solution on the volatile constituents of leaves and bracts of Origanum dictamnus.

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    Economakis, C; Skaltsa, Helen; Demetzos, Costas; Soković, M; Thanos, Costas A

    2002-10-23

    The chemical composition of the essential oils obtained from the leaves and bracts of hydroponically cultivated Origanum dictamnus were analyzed by GC-MS techniques. Three different concentrations of phosphorus (5, 30, and 60 mg/L) in the nutrient solution were used for the cultivation, using the nutrient film technique (NFT). A total of 46 different compounds were identified and significant differences (qualitative and quantitative) were observed between the samples. Carvacrol and p-cymene were identified as the main compounds in all samples analyzed, whereas thymoquinone was found in higher percentage in the leaves than in bracts. The essential oils were tested for their antibacterial activity against Gram-positive and Gram-negative bacteria. The oils obtained from the bracts were found to be more active. The results obtained from GC-MS analyses were submitted to chemometric analysis.

  17. Nutrient and salinity concentrations effects on quality and storability of cherry tomato fruits grown by hydroponic system

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    Mohammad Zahirul Islam

    2018-04-01

    Full Text Available ABSTRACT This study was conducted to investigate the effects of nutrient and salinity concentrations on the quality of deepflow technique hydroponic system cultivated cherry tomatoes (Lycopersicon esculentum Mill ‘Unicorn’. The conditions were: (1 control (NS-1 × nutrient Solution, Electrical Conductivity – EC: 2.5 mS∙cm–1; (2 2 × NS (2 × NS-Double NS, EC: 5 mS∙cm–1; (3 NS + 4.23 mM NaCl (NaCl-Sodium Chloride, EC: 5 mS∙cm–1; and (4 NS + 13.70 mM Sea Water – SW (EC: 7.5 mS∙cm–1. NS + 13.70 mM SW treatment showed the lowest fresh weight loss. Visual quality as well as shelf life was the longest in NS (1 × nutrient solution treated tomato fruits. The longest shelf life at 5 °C, 11 °C, and 24 °C were 21, 16, and 8 days, respectively, in NS (1 × nutrient solution treated tomato fruits. The highest firmness was recorded in NS (1 × nutrient solution treated tomato fruits, which was retained after storage. Moreover, NS + 13.70 mM SW treatment increased the cherry tomato fruit’s quality, especially soluble solids and sugar contents. These results indicate that salinity concentration has effect the soluble solids and sugar of cherry tomato fruits. In addition, nutrient concentration influenced the shelf life and firmness of cherry tomato fruits.

  18. Wheat cultivar tolerance to boron deficiency and toxicity in nutrient solution

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    Furlani Ângela Maria Cangiani

    2003-01-01

    Full Text Available Field symptoms of open spikelets in wheat were observed in specific cultivars and supposedly related to low B soils and differential B requirement among cultivars. This study aimed to evaluate the response of four wheat (Triticum aestivum L. cultivars, IAC 24, IAC 60, IAC 287 and IAC 289, to increasing B concentrations in nutrient solution. The experiment was set up in a randomized complete block design, with four replicates and five B concentrations (0.0, 0.05, 0.2, 0.8 and 2.0 mg L-1, during 1997/1998, in a greenhouse. Plants were grown to maturity and evaluated for plant height, spike number and length, open spikelet number, grains per spike, plant parts dry matter, B, P, K, Ca and Mg leaf concentrations and total nutrient contents. The visual symptoms of B deficiency consisted of open spikelets, distorted spikes without grains. 'IAC 60' and 'IAC 287' had higher B efficiency, with the highest grain yields in lower B concentrations. The 'IAC 287' and 'IAC 24' were more tolerant to the highest B concentrations. 'IAC 24' required more B for grain production as compared to the other cultivars. The critical leaf B concentration for deficiency was 25 mg kg-1 of dry matter tissue for all cultivars, and for toxicity were: 44 to 45 mg kg-1 for 'IAC 60' and 'IAC 289'; 228 and 318 mg kg-1 for 'IAC 24' and 'IAC 287', respectively. Except for the highest B level in the nutrient solution, the leaf P, K, Ca and Mg concentrations and whole plant contents were in an adequate range in the plants and did not vary among cultivars.

  19. Interactions between nitrate and chloride in nutrient solutions for substrate grown tomato

    NARCIS (Netherlands)

    Voogt, W.; Sonneveld, C.

    2004-01-01

    In two successive experiments tomato was grown at different Cl and NO3 concentrations in the root environment with rockwool as a sub-strate. The EC value in the nutrient solution was fairly constant, varying between 3.5 and 4.0 dS m-1 in all treatments. The NO3 concentrations in the treatments

  20. Nutrient supply of plants in aquaponic systems

    OpenAIRE

    Bittsánszky, András; Uzinger, Nikolett; Gyulai, Gábor; Mathis, Alex; Junge, Ranka; Villarroel, Morris; Kotzen, Benzion; Komives, Tamas

    2016-01-01

    In this preliminary article we present data on plant nutrient concentrations in aquaponic systems, and compare them to nutrient concentrations in “standard” hydroponic solutions. Our data shows that the nutrient concentrations supplied by the fish in aquaponic system are significantly lower for most nutrients, compared to hydroponic systems. Nevertheless, plants do thrive in solutions that have lower nutrient levels than “standard” hydroponic solutions. This is especially true for green leafy...

  1. Swift recovery of Sphagnum nutrient concentrations after excess supply.

    Science.gov (United States)

    Limpens, Juul; Heijmans, Monique M P D

    2008-08-01

    Although numerous studies have addressed the effects of increased N deposition on nutrient-poor environments such as raised bogs, few studies have dealt with to what extent, and on what time-scale, reductions in atmospheric N supply would lead to recovery of the ecosystems in question. Since a considerable part of the negative effects of elevated N deposition on raised bogs can be related to an imbalance in tissue nutrient concentrations of the dominant peat-former Sphagnum, changes in Sphagnum nutrient concentration after excess N supply may be used as an early indicator of ecosystem response. This study focuses on the N and P concentrations of Sphagnum magellanicum and Sphagnum fallax before, during and after a factorial fertilization experiment with N and P in two small peatlands subject to a background bulk deposition of 2 g N m(-2) year(-1). Three years of adding N (4.0 g N m(-2) year(-1)) increased the N concentration, and adding P (0.3 g P m(-2) year(-1)) increased the P concentration in Sphagnum relative to the control treatment at both sites. Fifteen months after the nutrient additions had ceased, N concentrations were similar to the control whereas P concentrations, although strongly reduced, were still slightly elevated. The changes in the N and P concentrations were accompanied by changes in the distribution of nutrients over the capitulum and the stem and were congruent with changes in translocation. Adding N reduced the stem P concentration, whereas adding P reduced the stem N concentration in favor of the capitulum. Sphagnum nutrient concentrations quickly respond to reductions in excess nutrient supply, indicating that a management policy aimed at reducing atmospheric nutrient input to bogs can yield results within a few years.

  2. Characterization of nutrient deficiency in Hancornia speciosa Gomes seedlings by omitting micronutrients from the nutrient solution

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    Layara Alexandre Bessa

    2013-06-01

    Full Text Available Hancornia speciosa Gomes (Mangaba tree is a fruit tree belonging to the Apocynaceae family and is native to Brazil. The production of seedlings of this species is limited by a lack of technical and nutritional expertise. To address this deficiency, this study aimed to characterize the visual symptoms of micronutrient deficiency and to assess growth and leaf nutrient accumulation in H. speciosa seedlings supplied with nutrient solutions that lack individual micronutrients. H. speciosa plants were grown in nutrient solution in a greenhouse according to a randomized block design, with four replicates. The treatments consisted of a group receiving complete nutrient solution and groups treated with a nutrient solution lacking one of the following micronutrients: boron (B, copper (Cu, iron (Fe, manganese (Mn, zinc (Zn, and molybdenum (Mo. The visual symptoms of nutrient deficiency were generally easy to characterize. Dry matter production was affected by the omission of micronutrients, and the treatment lacking Fe most limited the stem length, stem diameter, root length, and number of leaves in H. speciosa seedlings as well as the dry weight of leaves, the total dry weight, and the relative growth in H. speciosa plants. The micronutrient contents of H. speciosa leaves from plants receiving the complete nutrient solution treatment were, in decreasing order, Fe>Mn>Cu>Zn>B.

  3. Effect of increasing concentrations of lead, cadmium, chromium, nickel, or zinc on lettuce grown in nutrient solution

    Energy Technology Data Exchange (ETDEWEB)

    Foroughi, M.; Hoffmann, G.; Teicher, K.; Venter, F.

    1975-01-01

    Experiments were performed to examine concentrations at which excess symptoms could be expected, which kind of damage symptoms appear and in which amount the heavy metals are enriched in roots and leaves. The following results were revealed. Lettuce (Lactuca sativa L. var. capitata L.) can tolerate amounts of Cd below 1 ppm, of Ni below 2 ppm and of Pb below 20 ppm in the nutrient solution without any symptoms of excess. The growth of lettuce was mostly influenced by Cd, least of all by Pb. Only Ni caused specific poisoning symptoms. Heavy metals were enriched in different amounts in roots and leaves. The contents of Cd and Ni were more than twice as high as those of Pb. The heavy metals influenced the uptake and distribution of macro-elements more (nitrogen) or less (potassium) vigorously.

  4. Effect of interactions between carbon dioxide enrichment and NH4+/NO3- ratio on pH of culturing nutrient solution,growth and vigor of tomato root system

    Institute of Scientific and Technical Information of China (English)

    Juan LI; Jianmin ZHOU

    2008-01-01

    A growth chamber experiment was conducted to investigate the influence of NH4+/NO3- ratio and elevated CO2 concentration on the pH in nutrient solution,growth and root vigor system of tomato seedling roots,which attempts to understand whether the elevated CO2 concentration can alleviate the harmful effects of higher NH4+-N concentration in nutrient solutions on the tomato root system.Tomato (Lycopersicon esculenturn Mill.var.Hezuo 906) was grown in pots with nutrient solutions varying in NH4+/NO3- ratio (0:1,1:3,1:1,3:1and 1:0) and the growth chambers were supplied with with the growth process and CO2 concentration increased.At both CO2 levels,pH increased when 100% NO3--N was supplied and decreased in other treatments.The pH decrease in the nutrient solution was directly correlated to the NH4+-N proportion.The pH value was more reduced in 100% NH4+-N nutrient solution than increased in the 100% NO3--N nutrient solution.CO2 enrichment increased the dry weight of shoots and roots,root vigor system,total absorbing area and active absorbing area of tomato seedlings.All the measurement indexes above were increased in the elevated CO2 concentration treatment with the NO3- proportion increase in the nutrient solutions.Thus,under the elevated CO2 concentration,the dry weights of shoots and roots,root vigor system,total root absorbing area and active absorbing area were found to be inversely correlated to NH4+/NO3- ratio,leading to about 65.8%,78.0%,18.9%,12.9% and 18.9% increase,respectively,compared with that under the ambient CO2 concentration.Our results indicated that tomato seedling roots may benefit mostly from CO2 enrichment when 100% NO3--N nutrient solutions was supplied,but the CO2 concentration elevation did not alleviate the harmful effects when 100% NHa+-N was supplied.

  5. Influence of lead on atrazine uptake by rice (Oryza sativa L.) seedlings from nutrient solution.

    Science.gov (United States)

    Su, Yu-Hong; Zhu, Yong-Guan

    2005-01-01

    Atrazine is a widely used herbicide, and its persistence in soil and water causes environmental concerns. In the past, plant uptake processes are mainly investigated for single contaminants. However, in many cases, contaminants co-exist in environmental matrix, such as soil, and plant uptake of one contaminant may be influenced by its co-existing ones. The uptake of atrazine by rice seedlings (Oryza sativa L.) from nutrient solution through the roots was investigated in a solution culture, over an exposure period of 4 weeks. Atrazine accumulation in plant tissues was determined by gas chromatography, and lead was determined using atomic absorption spectrometry. With different ratios of atrazine and Pb2+ concentrations in solution, the observed atrazine concentrations in shoots and roots varied significantly. In atrazine-Pb2+ mixture systems, the added Pb2+ either increased or decreased the concentrations or BCFs of atrazine in seedlings (relative to those without Pb2+), depending on the atrazine-Pb2+ ratio in nutrient solution. The enhanced atrazine uptake results presumably from atrazine-Pb2+ complex formation. The reduced atrazine uptake, which occurred mainly at high atrazine concentrations, is attributed to atrazine toxicity that inhibited seedling growth and transpiration. The formation of atrazine-Pb2+ complex both in the solution and within plant tissues may affect the accumulation of both contaminants by rice plants.

  6. Concentração e conteúdo de nutrientes em lisianto, cultivado em hidroponia, em sistema NFT = Concentration and nutrient content in lisianthus grown in a hydroponic NFT system

    Directory of Open Access Journals (Sweden)

    Fernanda Alice Antonello Londero Backes

    2008-10-01

    Full Text Available O diagnóstico nutricional é fundamental para determinar as exigências das plantas quanto aos nutrientes, de forma a se proceder a um manejo adequado, de acordo com a espécie. Assim, para determinar as concentrações e conteúdos nutricionais adequados à produção e qualidade de plantas de lisianto em cultivo hidropônico, instalou-se um experimento onde as plantas foram cultivadas em sistema NFT, em diferentes soluções nutritivas. O experimento foi conduzido, segundo delineamento experimental em blocos casualizados, em esquema fatorial 4x3, totalizando 12 tratamentos, com três repetições. Ostratamentos foram compostos de quatro cultivares (Echo Champagne, Mariachi Pure White, Balboa Yellow e Ávila Blue Rim e três soluções nutritivas (Teste, Steiner modificada e Barbosa. Foram avaliadas as concentrações e os conteúdos dos nutrientes nas folhas e conteúdos na parte aérea das plantas. As plantas cultivadas nas soluções Barbosa eTeste apresentaram resultados satisfatórios quanto às concentrações e aos conteúdos de nutrientes, enquanto a solução Steiner modificada produziu plantas com limitações nutricionais.The nutritional diagnosis is fundamental for determining plantnutrients, in order to correctly manage the nutritional requirements for each species. Thus, in order to determine the ideal nutrient amount and concentration for obtaining the best yield and quality of lisianthus grown hydroponically, an experiment was conducted inwhich the plants were grown under the NFT system in different nutrient solutions. The experiment was conducted according to a random block design arrangement in a 4x3 factorial scheme, totaling 12 treatments with three repetitions. The treatments werecomprised of four cultivars (Echo Champagne, Mariachi Pure White, Balboa Yellow and Ávila Blue Rim and three nutrient solutions (Test, modified Steiner and Barbosa. In the leaves, nutrient concentration and content were evaluated; in the aerial

  7. Tolerance of physic nut plants to aluminum activity in nutrient solution

    OpenAIRE

    Lana, Maria do Carmo; Steiner, Fábio [UNESP; Zoz, Tiago [UNESP; Fey, Rubens; Frandoloso, Jucenei Fernando

    2013-01-01

    Plants have different levels of tolerance to phytotoxic effects of aluminum and the exploitation of this characteristic is of significant importance to the use of acid soils. This research aimed to evaluate the effect of aluminum activity in nutrient solution on growth of physic nut young plant. After seven days of adaptation, plants were submitted to Al concentrations of 0; 200; 400; 600; 800 and 1,000 μmol L-1, corresponding to Al3+ activity solution, of: 14.5, 21.4; 46.6; 75.6; 108.3 e 144...

  8. Lake nutrient stoichiometry is less predictable than nutrient concentrations at regional and sub-continental scales.

    Science.gov (United States)

    Collins, Sarah M; Oliver, Samantha K; Lapierre, Jean-Francois; Stanley, Emily H; Jones, John R; Wagner, Tyler; Soranno, Patricia A

    2017-07-01

    Production in many ecosystems is co-limited by multiple elements. While a known suite of drivers associated with nutrient sources, nutrient transport, and internal processing controls concentrations of phosphorus (P) and nitrogen (N) in lakes, much less is known about whether the drivers of single nutrient concentrations can also explain spatial or temporal variation in lake N:P stoichiometry. Predicting stoichiometry might be more complex than predicting concentrations of individual elements because some drivers have similar relationships with N and P, leading to a weak relationship with their ratio. Further, the dominant controls on elemental concentrations likely vary across regions, resulting in context dependent relationships between drivers, lake nutrients and their ratios. Here, we examine whether known drivers of N and P concentrations can explain variation in N:P stoichiometry, and whether explaining variation in stoichiometry differs across regions. We examined drivers of N:P in ~2,700 lakes at a sub-continental scale and two large regions nested within the sub-continental study area that have contrasting ecological context, including differences in the dominant type of land cover (agriculture vs. forest). At the sub-continental scale, lake nutrient concentrations were correlated with nutrient loading and lake internal processing, but stoichiometry was only weakly correlated to drivers of lake nutrients. At the regional scale, drivers that explained variation in nutrients and stoichiometry differed between regions. In the Midwestern U.S. region, dominated by agricultural land use, lake depth and the percentage of row crop agriculture were strong predictors of stoichiometry because only phosphorus was related to lake depth and only nitrogen was related to the percentage of row crop agriculture. In contrast, all drivers were related to N and P in similar ways in the Northeastern U.S. region, leading to weak relationships between drivers and stoichiometry

  9. Nutrient supply of plants in aquaponic systems

    Directory of Open Access Journals (Sweden)

    Andras Bittsanszky

    2016-10-01

    Full Text Available In this preliminary article we present data on plant nutrient concentrations in aquaponics systems, and we compare them to nutrient concentrations in “standard” hydroponic solutions. Our data shows that the nutrient concentrations supplied by the fish in the aquaponics system are significantly lower for most nutrients compared to hydroponic systems. Nevertheless, plants do thrive in solutions that have lower nutrient levels compared to “standard” hydroponic solutions. This is especially true for green leafy vegetables that rarely need additional nutritional supplementation. It is concluded that in the highly complex system of aquaponics, special care has to be taken, via continuous monitoring of the chemical composition of the circulating water, to provide adequate concentrations and ratios of nutrients, and especially for the potentially toxic component, ammonium. If certain plants require nutrient supplementation, we consider that one based on organic substances would be most beneficial. However, protocols for the application of such nutrient amendments still need to be developed.

  10. Nutrient solution and substrates for ‘cedro doce’ (Pochota fendleri seedling production

    Directory of Open Access Journals (Sweden)

    Oscar J. Smiderle

    Full Text Available ABSTRACT This study assessed the effect of different substrates and addition of nutrient solution on the production of Pochota fendleri seedlings, leaf contents of macro and micronutrients and chlorophyll a and b. The experimental design was completely randomized, in a 3 x 2 factorial scheme, with four replicates. The factors were three substrates, with or without addition of nutrient solution, composing six treatments: (T1 = sand; (T2 = soil; (T3 = sand + soil (1:1; (T4 = sand + nutrient solution; (T5 = soil + nutrient solution; (T6 = sand + soil + nutrient solution. Growth characteristics (height, collar diameter, shoot dry matter, root dry matter, root/shoot ratio and total dry matter and contents of macro- and micronutrients and chlorophyll a and b were evaluated. The use of nutrient solution reduces the time to obtain seedlings of Pochota fendleri, and it is important for proper growth and quality of seedlings. The sequence of nutritional requirement presented by Pochota fendleri seedlings in three substrates with addition of nutrient solution follows the descending order: macronutrients (N > Ca > K > Mg > P > S and micronutrients (Fe > Mn > B > Zn > Cu.

  11. Influence of nutrient solutions in an open-field soilless system on the quality characteristics and shelf life of fresh-cut red and green lettuces (Lactuca sativa L.) in different seasons.

    Science.gov (United States)

    Luna, María C; Martínez-Sánchez, Ascensión; Selma, María V; Tudela, Juan A; Baixauli, Carlos; Gil, María I

    2013-01-01

    Little information is available about the impact of nutrient solution ion concentration on quality characteristics and shelf life of fresh-cut lettuce grown in soilless systems in open field. Three lettuce genotypes, lollo rosso and red oak leaf as red-leafed genotypes and butterhead as green-leafed genotype, were studied. The influence of three nutrient solutions with low, medium and high ion concentrations, which varied in the macroanion (NO₃⁻) and macrocations (K⁺, Ca²⁺ and NH₄⁺), were compared in summer and winter. The nutrient solutions evaluated in this study for the production of lettuce in a soilless system did not strongly influence the quality characteristics of the raw material. When the ion concentration of the nutrient solution was increased, fresh weight decreased, although it depended on the genotype and season. Maturity index and dry matter content varied with the season but independently of the nutrient solution. In summer, maturity index was higher and dry matter lower than in winter. Initial texture and visual quality were not influenced by the nutrient solution. Medium ion concentration provided the highest content of vitamin C and phenolic compounds. Our observations pointed out that the genotype had a strong influence on the shelf life of the fresh-cut product with minor differences among nutrient solutions. In general, red-leafed lettuces showed the highest antioxidant content, helping the maintenance of sensory characteristics throughout storage. The combination of optimal nutrient solution ion concentration and suitable cultivar is considered essential to ensure lettuce post-cutting life. Copyright © 2012 Society of Chemical Industry.

  12. Measuring calcium, potassium, and nitrate in plant nutrient solutions using ion-selective electrodes in hydroponic greenhouse of some vegetables.

    Science.gov (United States)

    Vardar, Gökay; Altıkatoğlu, Melda; Ortaç, Deniz; Cemek, Mustafa; Işıldak, İbrahim

    2015-01-01

    Generally, the life cycle of plants depends on the uptake of essential nutrients in a balanced manner and on toxic elements being under a certain concentration. Lack of control of nutrient levels in nutrient solution can result in reduced plant growth and undesired conditions such as blossom-end rot. In this study, sensitivity and selectivity tests for various polyvinylchloride (PVC)-based ion-selective membranes were conducted to identify those suitable for measuring typical concentration ranges of macronutrients, that is, NO(3-), K(+), and Ca(2+), in hydroponic solutions. The sensitivity and selectivity of PVC-membrane-based ion-selective sensors prepared with tetradodecylammoniumnitrate for NO(3-), valinomycin for K(+), and Ca ionophore IV for Ca(2+) were found to be satisfactory for measuring NO(3-), K(+), and Ca(2+) ions in nutrient solutions over typical ranges of hydroponic concentrations. Potassium, calcium, and nitrate levels that were utilized by cucumber and tomato seedlings in the greenhouse were different. The findings show that tomato plants consumed less amounts of nitrate than cucumber plants over the first 2 months of their growth. We also found that the potassium intake was higher than other nutritional elements tested for all plants. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

  13. Nutrient Management in Recirculating Hydroponic Culture

    Science.gov (United States)

    Bugbee, Bruce

    2004-01-01

    There is an increasing need to recirculate and reuse nutrient solutions in order to reduce environmental and economic costs. However, one of the weakest points in hydroponics is the lack of information on managing the nutrient solution. Many growers and research scientists dump out nutrient solutions and refill at weekly intervals. Other authors have recommended measuring the concentrations of individual nutrients in solution as a key to nutrient control and maintenance. Dumping and replacing solution is unnecessary. Monitoring ions in solution is not always necessary; in fact the rapid depletion of some nutrients often causes people to add toxic amounts of nutrients to the solution. Monitoring ions in solution is interesting, but it is not the key to effective maintenance.

  14. Sterilization of Fusarium oxysporum by treatment of non-thermalequilibrium plasma in nutrient solution

    Science.gov (United States)

    Yasui, Shinji; Seki, Satoshi; Yoshida, Ryohei; Shoji, Kazuhiro; Terazoe, Hitoshi

    2016-01-01

    Fusarium wilt of spinach due to F. oxysporum infection is one of the most destructive root diseases in hydroponics in factories using the nutrient film technique. We investigated new technologies for the sterilization of microconidia of F. oxysporum by using a non-thermalequilibrium plasma treatment method in nutrient solution. Specifically, we investigated the sterilization capabilities of five types of gas (air, O2, N2, He, and Ar) used for plasma generation. The highest sterilization capability was achieved by using O2 plasma. However, ozone, which causes growth inhibition, was then generated and released into the atmosphere. The sterilization capability was lower when N2 or air plasma was used in the nutrient solution. It was confirmed that sterilization can be achieved by plasma treatment using inert gases that do not generate ozone; therefore, we determined that Ar plasma is the most preferable. In addition, we investigated the sterilization capabilities of other factors associated with Ar plasma generation, without direct plasma treatment. However, none of these other factors, which included Ar bubbling, pH reduction, increased temperature, hydrogen peroxide concentration, and UV radiation, could completely reproduce the results of direct plasma treatment. We assume that radicals such as O or OH may contribute significantly to the sterilization of microconidia of F. oxysporum in a nutrient solution.

  15. Fertilizer drawn forward osmosis process for sustainable water reuse to grow hydroponic lettuce using commercial nutrient solution

    KAUST Repository

    Chekli, Laura

    2017-03-10

    This study investigated the sustainable reuse of wastewater using fertilizer drawn forward osmosis (FDFO) process through osmotic dilution of commercial nutrient solution for hydroponics, a widely used technique for growing plants without soil. Results from the bench-scale experiments showed that the commercial hydroponic nutrient solution (i.e. solution containing water and essential nutrients) exhibited similar performance (i.e., water flux and reverse salt flux) to other inorganic draw solutions when treating synthetic wastewater. The use of hydroponic solution is highly advantageous since it provides all the required macro- (i.e., N, P and K) and micronutrients (i.e., Ca, Mg, S, Mn, B, Zn and Mo) in a single balanced solution and can therefore be used directly after dilution without the need to add any elements. After long-term operation (i.e. up to 75% water recovery), different physical cleaning methods were tested and results showed that hydraulic flushing can effectively restore up to 75% of the initial water flux while osmotic backwashing was able to restore the initial water flux by more than 95%; illustrating the low-fouling potential of the FDFO process. Pilot-scale studies demonstrated that the FDFO process is able to produce the required nutrient concentration and final water quality (i.e., pH and conductivity) suitable for hydroponic applications. Coupling FDFO with pressure assisted osmosis (PAO) in the later stages could help in saving operational costs (i.e., energy and membrane replacement costs). Finally, the test application of nutrient solution produced by the pilot FDFO process to hydroponic lettuce showed similar growth pattern as the control without any signs of nutrient deficiency.

  16. Effect of mycorrhiza and phosphorus content in nutrient solution on the yield and nutritional status of tomato plants grown on rockwool or coconut coir

    Directory of Open Access Journals (Sweden)

    Iwona Kowalska

    2015-03-01

    Full Text Available Effects of P level in nutrient solution and the colonization of roots by arbuscular mycorrhizal fungi (AMF on P uptake by tomato plants, their nutritional status, yield and quality of fruits were studied. Plants were grown on rockwool or coconut coir. Inoculation by a mixture of several AMF species was performed three times during the growing period. The mycorrhizal frequency in roots inoculated with AMF amounted to 35.79 – 50.82%. The highest level of mycorrhiza was found in plants receiving nutrient solution with a lower concentration of P. Among the experimental factors, only P level influenced the fruit yield, being higher from plants receiving a nutrient solution with a higher P level. A higher concentration of P in nutrient solution imposed better nutritional status of plants. Higher contents of ascorbic acid and total soluble sugars were found in fruits collected from inoculated plants, grown on rockwool.

  17. Cerium enhances germination and shoot growth, and alters mineral nutrient concentration in rice

    Science.gov (United States)

    García-Morales, Soledad; Pérez-Sato, Juan Antonio

    2018-01-01

    Cerium (Ce) belongs to the rare earth elements (REEs), and although it is not essential for plants, it can stimulate growth and other physiological processes. The objective of this research was to evaluate the effect of Ce on seed germination, initial seedling growth, and vegetative growth in rice (Oryza sativa L.) cv. Morelos A-98. During the germination process, the seeds were treated with Ce concentrations of 0, 4, 8, and 12 μM; after 5 d, germination percentage was recorded and after 10 d seedling growth was measured. For vegetative growth, a hydroponic system was established where 14-d-old plants without previous Ce treatment were transferred into nutrient solution. After two weeks of acclimatizing, 0, 25, 50, and 100 μM Ce were added to the nutrient solution for 28 d. Ce significantly increased germination and the initial growth variables of the seedlings. During vegetative growth, Ce increased plant height, number of tillers, root volume, and shoot fresh and dry biomass, without affecting root biomass weight. With low Ce concentrations (25 and 50 μM), the concentrations of chlorophylls and amino acids in the shoots were similar to those in the control, like amino acid concentration in the roots at a concentration of 25 μM Ce. Conversely, the concentration of total sugars increased in the shoot with the application of 25, 50, and 100 μM Ce, and in the roots with the application of 50 μM Ce. Also, Ce did not affect the concentration of macro or micronutrients in the shoots. However, in the roots, the high Ce concentration decreased the concentrations of Ca, Fe, Mn, and Zn, while the Mg concentration increased. Our results indicate that Ce, at the right concentrations, can function as a biostimulant in rice germination and growth. PMID:29579100

  18. A targeted management of the nutrient solution in a soilless tomato crop according to plant needs

    Directory of Open Access Journals (Sweden)

    Angelo eSignore

    2016-03-01

    Full Text Available The adoption of closed soilless systems is useful in minimizing the environmental impact of the greenhouse crops. Instead, a significant problem in closed soilless systems is represented by the accumulation of ions in the recycled nutrient solution, in particular the unabsorbed or poorly absorbed ones. To overcome such problem, we: 1 studied the effect of several values of the electrical conductivity (EC of nutrient solution in a NFT (Nutrient Film Technique system on a cherry type tomato crop, and 2 define a NS (called recovery solution, based on the concept of uptake concentration and transpiration-biomass ratio, that fits the real needs of the plant with respect to water and nutrients. Three levels of EC set point (SP, above which the NS was completely replaced (SP5, SP7.5, and SP10 for the EC limit of 5, 7.5 and 10 dS m-1, respectively, were established. The SP10 treatment yield was not different from other treatments, and it allowed a better quality of the berries (for dry matter and total soluble solids and higher environmental sustainability due to a lower discharge of total nutrients into the environment (37 and 59% with respect to SP7.5 and SP5, respectively.The recovery solution used in the second trial allowed a more punctual NS management, by adapting to the real needs of the crop. Moreover, it allowed a lesser amount of water and nutrients to be discharged into the environment and a better use of brackish water, due to a more accurate management of the EC of the NS. The targeted management, based on transpiration-biomass ratio, indicates that, in some stages of the plant cycle, the nutrient solution used can be diluted, in order to save water and nutrients. With such management a closed cycle can be realized without affecting the yield, but improving the quality of the tomato berries.

  19. Computer model of hydroponics nutrient solution pH control using ammonium.

    Science.gov (United States)

    Pitts, M; Stutte, G

    1999-01-01

    A computer simulation of a hydroponics-based plant growth chamber using ammonium to control pH was constructed to determine the feasibility of such a system. In nitrate-based recirculating hydroponics systems, the pH will increase as plants release hydroxide ions into the nutrient solution to maintain plant charge balance. Ammonium is an attractive alternative to traditional pH controls in an ALSS, but requires careful monitoring and control to avoid overdosing the plants with ammonium. The primary advantage of using NH4+ for pH control is that it exploits the existing plant nutrient uptake charge balance mechanisms to maintain solution pH. The simulation models growth, nitrogen uptake, and pH of a l-m2 stand of wheat. Simulation results indicated that ammonium-based control of nutrient solution pH is feasible using a proportional integral controller. Use of a 1 mmol/L buffer (Ka = 1.6 x 10(-6)) in the nutrient solution is required.

  20. Sudden increase in atmospheric concentration reveals strong coupling between shoot carbon uptake and root nutrient uptake in young walnut trees

    International Nuclear Information System (INIS)

    Delaire, M.; Sigogne, M.; Beaujard, F.; Frak, E.; Adam, B.; Le Roux, X.

    2005-01-01

    Short-term effects of a sudden increase in carbon dioxide concentration on nutrient uptake by roots during vegetative growth was studied in young walnut trees. Rates of carbon dioxide uptake and water loss by individual trees were determined by a branch bag method from three days before and six days after carbon dioxide concentration was increased. Nutrient uptake rates were measured concurrently by a hydroponic recirculating nutrient solution system. Carbon dioxide uptake rates increased greatly with increasing atmospheric carbon dioxide; nutrient uptake rates were proportional to carbon dioxide uptake rates, except for the phosphorus ion. Daily water loss rates were only slightly affected by elevated carbon dioxide. Overall, it was concluded that in the presence of non-limiting supplies of water and nutrients, root nutrient uptake and shoot carbon assimilation are strongly coupled in the short term in young walnut trees despite the important carbon and nutrient storage capacities od woody species. 45 refs., 7 figs

  1. Nutrient concentration in leaves, a tool for nutritional diagnosis in cocoa.

    Directory of Open Access Journals (Sweden)

    Yina Jazbleidi Puentes-Páramo

    2016-06-01

    Full Text Available The aim of this study was to estimate the foliar concentrations in cocoa farming (Theobroma cacao L as a diagnostic tool of their nutritional status. At the Research Center of the National Federation of Cocoa Producers (Fedecacao located in Miranda-Cauca, Colombia, the study assessed the effect of five doses of NPK fertilization in nutrient concentration in leaves of four cocoa clones CCN-51, TSH-565, ICS-39, and ICS-95 from 20102012. Experimental design was randomized complete block design with five treatments: TR(control, T1(25% NPK, T2(50% NPK, T3(75% NPK, T4(100% NPK and four replicates. The concentration of 11 nutrients (N, P, K+, Ca2+, S, Mg2+, B, Zn2+, Cu2+, Fe2+, Mn2+ and their relation with yield was evaluated for three years. Results showed differences in the foliar concentration of nutrients assessed by effect of treatments, by clone, and by clone*treatment interaction. The foliar concentration used was derived from higher yield-related treatment, whereby, a proposal for nutritional diagnosis in cocoa based on nutrient monitoring was created to evaluate nutrient concentration in leaves.

  2. Nutrient uptake dynamics across a gradient of nutrient concentrations and ratios at the landscape scale

    Science.gov (United States)

    Gibson, Catherine A.; O'Reilly, Catherine M.; Conine, Andrea L.; Lipshutz, Sondra M.

    2015-02-01

    Understanding interactions between nutrient cycles is essential for recognizing and remediating human impacts on water quality, yet multielemental approaches to studying nutrient cycling in streams are currently rare. Here we utilized a relatively new approach (tracer additions for spiraling curve characterization) to examine uptake dynamics for three essential nutrients across a landscape that varied in absolute and relative nutrient availability. We measured nutrient uptake for soluble reactive phosphorous, ammonium-nitrogen, and nitrate-nitrogen in 16 headwater streams in the Catskill Mountains, New York. Across the landscape, ammonium-nitrogen and soluble reactive phosphorus had shorter uptake lengths and higher uptake velocities than nitrate-nitrogen. Ammonium-nitrogen and soluble reactive phosphorus uptake velocities were tightly correlated, and the slope of the relationship did not differ from one, suggesting strong demand for both nutrients despite the high ambient water column dissolved inorganic nitrogen: soluble reactive phosphorus ratios. Ammonium-nitrogen appeared to be the preferred form of nitrogen despite much higher nitrate-nitrogen concentrations. The uptake rate of nitrate-nitrogen was positively correlated with ambient soluble reactive phosphorus concentration and soluble reactive phosphorus areal uptake rate, suggesting that higher soluble reactive phosphorus concentrations alleviate phosphorus limitation and facilitate nitrate-nitrogen uptake. In addition, these streams retained a large proportion of soluble reactive phosphorus, ammonium-nitrogen, and nitrate-nitrogen supplied by the watershed, demonstrating that these streams are important landscape filters for nutrients. Together, these results (1) indicated phosphorus limitation across the landscape but similarly high demand for ammonium-nitrogen and (2) suggested that nitrate-nitrogen uptake was influenced by variability in soluble reactive phosphorus availability and preference for

  3. Doses de N e K no tomateiro sob estresse salino: I. Concentração de nutrientes no solo e na planta Doses of N and K in tomato under saline stress: I. Concentration of nutrients in the soil solution and plant

    Directory of Open Access Journals (Sweden)

    Flávio F. Blanco

    2008-02-01

    Full Text Available Em geral, culturas tolerantes à salinidade geralmente apresentam maiores teores foliares de certos nutrientes, sugerindo que a adubação em culturas sensíveis poderia elevar os teores desses nutrientes nas folhas, aumentando sua tolerância aos sais. Este trabalho teve o objetivo de estudar os efeitos do N e do K na condutividade elétrica, pH e concentração de nutrientes da solução do solo e nos teores de nutrientes e prolina nas folhas do tomateiro irrigado com água salina. Os tratamentos foram compostos da combinação de três níveis de N (7,5; 15,0 e 22,5 g por planta e de K (8, 16 e 24 gK2O por planta aplicados via fertirrigação por gotejamento, no esquema fatorial 3 x 3, com cinco repetições, sendo que à água de irrigação foram adicionados os sais cloreto de sódio e cloreto de cálcio, para obtenção de condutividade elétrica da água de 9,5 dS m-1. As concentrações de NO3 e K na solução do solo e de N e K nas folhas do tomateiro aumentaram com as doses de N e K mas não promoveram redução dos teores de Cl nem de Na nas folhas das plantas. O aumento do teor de prolina com as doses de K e a redução de Cl/N com as doses de N, sugerem que o aumento na adubação potássica e nitrogenada pode ser benéfico para o tomateiro sob condições de salinidade moderada.Crops tolerant to salinity generally present higher concentrations of some nutrients in the leaves, suggesting that the fertilization of sensitive crops could increase the contents of these nutrients in the leaves to increase the crop tolerance to salts. This work had the objective of studying the effects of N and K on electrical conductivity, pH and nutrient concentrations of soil solution and on concentration of nutrients and proline in the leaves of tomatos irrigated with saline water. The treatments were composed of the combination of three levels of N (7.5, 15.0 and 22.5 g per plant and K (8, 16 and 24 g K2O per plant applied by drip fertigation, in a 3

  4. Trace elements and nutrients adsorption onto nano-maghemite in a contaminated-soil solution: A geochemical/statistical approach.

    Science.gov (United States)

    Martínez-Fernández, Domingo; Bingöl, Deniz; Komárek, Michael

    2014-07-15

    Two experiments were carried out to study the competition for adsorption between trace elements (TEs) and nutrients following the application of nano-maghemite (NM) (iron nano-oxide; Fe2O3) to a soil solution (the 0.01molL(-1) CaCl2 extract of a TEs-contaminated soil). In the first, the nutrients K, N, and P were added to create a set of combinations: potential availability of TEs during their interaction with NM and nutrients were studied. In the second, response surface methodology was used to develop predictive models by central composite design (CCD) for competition between TEs and the nutrients K and N for adsorption onto NM. The addition of NM to the soil solution reduced specifically the concentrations of available As and Cd, but the TE-adsorption capacity of NM decreased as the P concentration increased. The CCD provided more concise and valuable information, appropriate to estimate the behavior of NM sequestering TEs: according to the suggested models, K(+) and NH4(+) were important factors for Ca, Fe, Mg, Mn, Na, and Zn adsorption (Radj(2)=95%, except for Zn with Radj(2)=87%). The obtained information and models can be used to predict the effectiveness of NM for the stabilization of TEs, crucial during the phytoremediation of contaminated soils. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Concentration of nutrient solution in the hydroponic production of potato minitubers Concentração da solução nutritiva na produção hidropônica de minitubérculos de batata

    Directory of Open Access Journals (Sweden)

    Manuel Benito Novella

    2008-09-01

    Full Text Available The effect of the nutrient solution concentration on potato plant growth and minituber yield were determined in a sand closed hydroponic system. Minitubers and micropropagated plantlets of the cv. 'Macaca' were used. Treatments were five nutrient solution concentrations at electrical conductivities (EC of 1.0 (T1, 2.2 (T2, 3.4 (T3, 4.7 (T4 and 5.8dS m-1 (T5. The split plot randomised experimental design was used with three replications. Plants from minitubers produced higher fresh and mean weight of minitubers, shoot dry mass and leaf area index than the micropropagated ones. However, higher dry mass of minitubers was found with micropropagated plantlets compared to minitubers. The concentration of the nutrient solution did not affect minituber number. Increasing the nutrient solution concentration decreased total and minituber dry mass production of micropropagated plantlets and plant growth and minituber production of minituber-originated plants. Low concentration of nutrient solution at an EC of about 1.0dS m-1 can be used in the hydroponic production of potato minitubers of both micropropagated and minituber-originated plants.Neste trabalho foi determinado o efeito da concentração da solução nutritiva no crescimento e na produtividade de minitubérculos de batata em um sistema hidropônico fechado empregando areia como substrato. Plântulas micropropagadas e minitubérculos foram plantados em 24 de março de 2004. Os tratamentos foram cinco soluções nutritivas com condutividades elétricas (CE de 1,0 (T1, 2,2 (T2, 3,4 (T3, 4,7 (T4 e 5,8dS m-1 (T5. O experimento foi conduzido em parcelas subdivididas no delineamento inteiramente casualizado com três repetições. Plantas originadas de minitubérculos produziram mais massa fresca total e média de minitubérculos, massa seca da parte aérea e maior índice de área foliar que plantas micropropagadas. Entretanto, maior massa seca dos minitubérculos foi obtida em plantas micropropagadas

  6. Long-term effects of rainforest disturbance on the nutrient composition of throughfall, organic layer percolate and soil solution at Mt. Kilimanjaro.

    Science.gov (United States)

    Schrumpf, Marion; Axmacher, Jan C; Zech, Wolfgang; Lehmann, Johannes; Lyaruu, Herbert V C

    2007-04-15

    At the lower parts of the forest belt at Mt. Kilimanjaro, selective logging has led to a mosaic of mature forest, old secondary forests ( approximately 60 years), and old clearings ( approximately 10 years) covered by shrub vegetation. These variations in the vegetation are reflected by differences in nutrient leaching from the canopy and in both amount and quality of litter reaching the ground, thereby also influencing mineralization rates and the composition of seepage water in litter percolate and soil solution. The aim of this study was to investigate how above- and belowground nutrient dynamics vary between regeneration stages, and if forest regeneration at the clearings is hampered by a deterioration of abiotic site conditions. K, Mg, Ca, Na and N compounds were analysed in rainfall, throughfall, organic layer percolate and the soil solution to a depth of 1.00 m at three clearings, three secondary forest and four mature forest sites. Element fluxes via throughfall showed only small variations among regeneration stages except for K and NO(3)-N. With 57-83 kg ha(-1) a(-1)and 2.6-4.1 kg ha(-1) a(-1) respectively, K and NO(3)-N fluxes via throughfall were significantly higher at the clearings than at the mature forest sites (32-37 and 0.7-1.0 kg ha(-1) a(-1) for K and NO(3)-N). In organic layer percolate and in soil solution at 0.15-m soil depth, concentrations of K, Mg, Ca and N were highest at the clearings. In the organic layer percolate, median K concentrations were e.g. 7.4 mg l(-1) for the clearings but only 1.4 mg l(-1) for the mature forests, and for NO(3)-N, median concentrations were 3.1 mg l(-1) for the clearings but only 0.92 mg l(-1) for the mature forest sites. Still, differences in annual means between clearings and mature forests were not always significant due to a high variability within the clearings. With the exception of NO(3)-N, belowground nutrient concentrations in secondary forests ranged between concentrations in mature forests and

  7. Part 2: A field study of enhanced remediation of Toluene in the vadose zone using a nutrient solution

    Science.gov (United States)

    Tindall, J.A.; Weeks, E.P.; Friedel, M.

    2005-01-01

    The objective of this study was to test the effectiveness of a nitrate-rich nutrient solution and hydrogen peroxide (H2O2) to enhance in-situ microbial remediation of toluene in the unsaturated zone. Three sand-filled plots were tested in three phases (each phase lasting approximately 2 weeks). During the control phase, toluene was applied uniformly via sprinkler irrigation. Passive remediation was allowed to occur during this phase. A modified Hoagland nutrient solution, concentrated in 150 L of water, was tested during the second phase. The final phase involved addition of 230 moles of H2O2 in 150 L of water to increase the available oxygen needed for aerobic biodegradation. During the first phase, measured toluene concentrations in soil gas were reduced from 120 ppm to 25 ppm in 14 days. After the addition of nutrients during the second phase, concentrations were reduced from 90 ppm to about 8 ppm within 14 days, and for the third phase (H 2O2), toluene concentrations were about 1 ppm after only 5 days. Initial results suggest that this method could be an effective means of remediating a contaminated site, directly after a BTEX spill, without the intrusiveness and high cost of other abatement technologies such as bioventing or soil-vapor extraction. However, further tests need to be completed to determine the effect of each of the BTEX components. ?? Springer 2005.

  8. An Integrated Multimodal Sensor for the On-site Monitoring of the Water Content and Nutrient Concentration of Soil by Measuring the Phase and Electrical Conductivity

    Directory of Open Access Journals (Sweden)

    Masato FUTAGAWA

    2012-03-01

    Full Text Available We have fabricated a new multimodal sensor chip which is capable of simultaneous on-site measurements of the water content and nutrient concentration. Until now, in agriculture, water content sensors, such as TDR sensors, have been unable to provide accurate measurements, since these sensors are affected by the nutrient concentration in the soil solution. Therefore, tensiometers have generally been used. However, these are large-scale sensors and are not suitable for the precise measurements required in agriculture. Our proposed sensors are the world’s first to enable independent measurements of the water content and nutrient concentration.

  9. The effect of pH on phosphorus availability and speciation in an aquaponics nutrient solution.

    Science.gov (United States)

    Cerozi, Brunno da Silva; Fitzsimmons, Kevin

    2016-11-01

    The interaction between the main ions in aquaponics nutrient solutions affects chemical composition and availability of nutrients, and nutrient uptake by plant roots. This study determined the effect of pH on phosphorus (P) speciation and availability in an aquaponics nutrient solution and used Visual MINTEQ to simulate P species and P activity. In both experimental and simulated results, P availability decreased with increase in pH of aquaponics nutrient solutions. According to simulations, P binds to several cations leaving less free phosphate ions available in solution. High pH values resulted in the formation of insoluble calcium phosphate species. The study also demonstrated the importance of organic matter and alkalinity in keeping free phosphate ions in solution at high pH ranges. It is recommended though that pH in aquaponics systems is maintained at a 5.5-7.2 range for optimal availability and uptake by plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Gas exchange, phisiological indexes and ionic accumulation in Annona emarginata (Schltdl. H. Rainer seedlings in nutrients solution

    Directory of Open Access Journals (Sweden)

    Daniel Baron

    2013-06-01

    Full Text Available "Araticum-de-terra-fria" (Annona emarginata (Schltdl. H. Rainer has been consider a good alternative in rootstock production for the main commercial Annonaceae species. Although this species develops in different soil and climate conditions, there is no understanding by the physiological responses of this species at different nutritional levels. Thus, the objective of this study was to evaluate the influence of different ionic strengths on development of vegetative species known as "Araticum-de-terra-fria". It was evaluated in seedlings grown in different ionic strengths (25% I, 50% I, 75% I and 100% I of the complete nutrient solution Hoagland and Arnon (1950 nº 2, for 140 days, the following characteristics: Gas Exchange (CO2 assimilation rate, stomatal conductance, internal CO2 concentration, transpiration rate, water use efficiency, Rubisco carboxylation efficiency; Vegetative growth characteristics (diameter, leaf number, dry matter; Physiological Indexes (leaf area ratio, specific leaf area, relative growth rate, net assimilation rate, leaf weight ratio and Ionic Accumulation (nutrients leaf analysis. Seedlings grown under 50% I showed the highest values of Leaf CO2 assimilation rate, water use efficiency, carboxylation efficiency, growth, relative growth rate, net assimilation rate and ionic accumulation in the total dry matter. So it is concluded that "Araticum-de-terra-fria" seedlings grown under intermediate nutrient concentrations of complete nutrient solution Hoagland and Arnon (1950 nº 2, explored more adequately their physiological potential that justify their adaptation in different nutritional conditions and allow reducing the amount of mineral nutrition of seedlings production.

  11. Effect of pH Upper Control Limit on Nutrient Solution Component and Water Spinach Growth under Hydroponics

    OpenAIRE

    Xuzhang Xue; Yinkun Li; Feng Li; Fang Zhang; Wenzhong Guo

    2015-01-01

    In this study, experiment with four levels of nutrient solution pH control upper limit was conducted to explore the optimal nutrient solution pH management scheme under hydroponics by evaluating the nutrient solution characters i.e., pH, Electric Conductivity (EC), nitrate, soluble phosphorus (soluble-P), water spinach growth and quality. The results showed that the nutrient solution pH was 8.2 and unsuitable for water spinach growth under the treatment with no pH regulation during the experi...

  12. Effect of CO2 Enrichment on the Growth and Nutrient Uptake of Tomato Seedlings

    Institute of Scientific and Technical Information of China (English)

    LI Juan; ZHOU Jian-Min; DUAN Zeng-Qiang; DU Chang-Wen; WANG Huo-Yan

    2007-01-01

    Exposing tomato seedlings to elevated CO2 concentrations may have potentially profound impacts on the tomato yield and quality. A growth chamber experiment was designed to estimate how different nutrient concentrations influenced the effect of elevated CO2 on the growth and nutrient uptake of tomato seedlings. Tomato (Hezuo 906) was grown in pots placed in controlled growth chambers and was subjected to ambient or elevated CO2 (360 or 720 μL L-1), and four nutrient solutions of different strengths (1/2-, 1/4-, 1/8-, and 1/16-strength Japan Yamazaki nutrient solutions) in a completely randomized design. The results indicated that some agricultural characteristics of the tomato seedlings such as the plant height, stem thickness, total dry and fresh weights of the leaves, stems and roots, the G value (G value = total plant dry weight/seedling age),and the seedling vigor index (seedling vigor index = stem thickness/(plant height × total plant dry weight) increased with the elevated CO2, and the increases were strongly dependent on the nutrient solution concentrations, being greater with higher nutrient solution concentrations. The elevated CO2 did not alter the ratio of root to shoot. The total N, P, K, and C absorbed from all the solutions except P in the 1/8- and 1/16-strength nutrient solutions increased in the elevated CO2 treatment. These results demonstrate that the nutrient demands of the tomato seedlings increased at elevated CO2 concentrations.

  13. Improving tolerance of sunflower and safflower during growth stages to salinity through foliar spray of nutrient solutions

    International Nuclear Information System (INIS)

    Jabeen, N.; Ahmad, R.

    2012-01-01

    The effect of salinity and foliar application of nutrient solutions on sunflower and safflower in vegetative and reproductive phases of the growth were investigated in Bio saline Research Field, University of Karachi, Pakistan. The seeds were sown in pots under non saline condition and saline water irrigation was started at three leaf stage after germination. Different concentration of saline water were made by dissolving 3g and 6g sea salt per litre of tap water, equivalent to an EC of 4.8 and 8.6 dS/m respectively. Nutrient solution (KNO/sub 3 /, H/sub 3/ BO/sub 3/, Fe-EDTA or its mixture) was sprayed thrice, i.e., 45, 75 and 95 days after planting. KNO/sub 3/ was given at the rate 250 ppm and other H/sub 3/ BO/sub 3/ and Fe-EDTA was given at the rate 5 ppm. Salinity caused a significant reduction in nutrient uptake, height, biomass and yield of both sunflower and safflower. Foliar application of macro and micro nutrients (i.e. KNO/sub 3/, H/sub 3/BO/sub 3/, Fe-EDTA and mixture of KNO/sub 3/ + H/sub 3/BO/sub 3/ + Fe-EDTA) partially minimized the salt induced deficiency and showed significant increase in height, fresh and dry biomass, number and weight of seeds, and amount of oil per sunflower and safflower plant irrespective to their growth under non saline or saline conditions. Among the nutrient solutions, mixture of KNO/sub 3/+ H/sub 3/BO/sub 3/ + Fe-EDTA seemed to be the most effective followed by H/sub 3/ BO/sub 3/ and Fe-EDTA. These results suggested that foliar application of nutrients could be used to improve plant tolerance to salinity by alleviating the adverse effects of salinity on growth and reproductive yield. (author)

  14. Limiting nutrient emission from a cut rose closed system by high-flux irrigation and low nutrient concentrations?

    NARCIS (Netherlands)

    Baas, R.; Berg, van der D.

    2004-01-01

    A two-year project was aimed at decreasing nutrient emission from closed nutrient systems by using high irrigation rates in order to allow lower EC levels in the presence of accumulated Na and Cl. Experimental variables were growing media, irrigation frequencies, EC and NaCl concentrations for cut

  15. Effect of organic and inorganic fertilizers on nutrient concentrations ...

    African Journals Online (AJOL)

    Effect of organic and inorganic fertilizers on nutrient concentrations in plantain ( Musa spp.) ... Fruit parameters measured were fruit weight, edible proportion and pulp dry matter content; also, the concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), iron (Fe) and zinc (Zn) in fruits were determined.

  16. Automated pH Control of Nutrient Solution in a Hydroponic Plant Growth System

    Science.gov (United States)

    Smith, B.; Dogan, N.; Aglan, H.; Mortley, D.; Loretan, P.

    1998-01-01

    Over, the years, NASA has played an important role in providing to and the development of automated nutrient delivery and monitoring, systems for growing crops hydroponically for long term space missions. One example are the systems used in the Biomass Production Chamber (BPC) at Kennedy Space Center (KSC). The current KSC monitoring system is based on an engineering workstation using standard analog/digital input/output hardware and custom written software. The monitoring system uses completely separate sensors to provide a check of control sensor accuracy and has the ability to graphically display and store data form past experiment so that they are available for data analysis [Fortson, 1992]. In many cases, growing systems have not been fitted with the kind of automated control systems as used at KSC. The Center for Food and Environmental Systems for Human Exploration of Space (CFESH) located on the campus of Tuskegee University, has effectively grown sweetpotatoes and peanuts hydroponically for the past five years. However they have adjusted the pH electrical conductivity and volume of the hydroponic nutrient solution only manually at times when the solution was to be replenished or changed out according to its protocol (e.g. one-week, two-week, or two-day cycle). But the pH of the nutrient solution flowing through the channel is neither known nor controlled between the update, change out, or replenishment period. Thus, the pH of the nutrient solution is not held at an optimum level over the span of the plant's growth cycle. To solve this dilemma, an automated system for the control and data logging of pH data relative to sweetpotato production using the nutrient film technique (NFT) has been developed, This paper discusses a microprocessor-based system, which was designed to monitor, control, and record the pH of a nutrient solution used for growing sweetpotatoes using NFT.

  17. Human skin condition and its associations with nutrient concentrations in serum and diet

    NARCIS (Netherlands)

    Boelsma, E.; Vijver, L.P.L. van de; Goldbohm, R.A.; Klöpping-Ketelaars, I.A.A.; Hendriks, H.F.J.; Roza, L.

    2003-01-01

    Background: Nutritional factors exert promising actions on the skin, but only scant information is available on the modulating effects of physiologic concentrations of nutrients on the skin condition of humans. Objective: The objective was to evaluate whether nutrient concentrations in serum and

  18. The Concentration of Nutrients in Tissues of Plantation-Grown Eastern Cottonwood (Populus deltoides Bart.)

    Science.gov (United States)

    M. G. Shelton; L. E. Nelson; G. L. Switzer; B. G. Blackmon

    1981-01-01

    Nutrient concentrations were determined for 10 tissues from each of 24 cottonwood trees that ranged in age from four to 16 years. Highest concentrations occurred in the most physiologically active tissues; i.e., stemtips, current branches and foliage. Tree age had little influence on the variation in nutrient concentration of tissues. Some differences in concentrations...

  19. Nutrient concentrations in coarse and fine woody debris of Populus tremuloides Michx.-dominated forests, northern Minnesota, USA

    Science.gov (United States)

    Klockow, Paul A.; D'Amato, Anthony W.; Bradford, John B.; Fraver, Shawn

    2014-01-01

    Contemporary forest harvesting practices, specifically harvesting woody biomass as a source of bioenergy feedstock, may remove more woody debris from a site than conventional harvesting. Woody debris, particularly smaller diameter woody debris, plays a key role in maintaining ecosystem nutrient stores following disturbance. Understanding nutrient concentrations within woody debris is necessary for assessing the long-term nutrient balance consequences of altered woody debris retention, particularly in forests slated for use as bioenergy feedstocks. Nutrient concentrations in downed woody debris of various sizes, decay classes, and species were characterized within one such forest type, Populus tremuloides Michx.-dominated forests of northern Minnesota, USA. Nutrient concentrations differed significantly between size and decay classes and generally increased as decay progressed. Fine woody debris (≤ 7.5 cm diameter) had higher nutrient concentrations than coarse woody debris (> 7.5 cm diameter) for all nutrients examined except Na and Mn, and nutrient concentrations varied among species. Concentrations of N, Mn, Al, Fe, and Zn in coarse woody debris increased between one and three orders of magnitude, while K decreased by an order of magnitude with progressing decay. The variations in nutrient concentrations observed here underscore the complexity of woody debris nutrient stores in forested ecosystems and suggest that retaining fine woody debris at harvest may provide a potentially important source of nutrients following intensive removals of bioenergy feedstocks.

  20. Nutrient Infiltrate Concentrations from Three Permeable Pavement Types

    Science.gov (United States)

    While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types have on nutrient concentrations present in stormwater runoff are limited. In 2009, the U.S. EPA constructed a 0.4-ha...

  1. Calcium and potassium contents in nutrient solution on Phoma leaf spot intensity in coffee seedlings

    Directory of Open Access Journals (Sweden)

    Aricléia de Moraes Catarino

    Full Text Available ABSTRACT Coffee is one of the main export commodities of Brazilian agribusiness. Phoma leaf spot [Phoma tarda (Stewart Boerema & Bollen] is one of the most important coffee fungal diseases in Brazil. Therefore, this study aimed to evaluate the intensity of Phoma leaf spot in coffee seedlings supplied with different rates of Ca+2 and K+. The study was conducted under controlled conditions in a growth chamber, at the Department of Phytopathology - UFLA, from February 2010 to December 2011. The assay was repeated twice under the same conditions. The nutrient solutions consisted of five concentrations of K+ (3, 4, 5, 6, 7 mmol L-1 and Ca+2 (2, 4, 6, 8 and 10 mmol L-1. The experiment was arranged in a randomized block design, with 25 treatments and three replicates, with two plants per plot. The areas under incidence progress curve (AUIPC and severity (AUSPC were calculated. At the lowest rate of Ca2+ (2 mmol L-1 and highest K+ (6 and 7 mmol L-1, approximately, the AUIPC was the smallest. For the AUSPC, the lowest rates of Ca+2 and K+ resulted in the lowest severities. Supply of Ca+2 and K+ in nutrient solution reduced AUIPC and AUSPC of Phoma leaf spot, and these nutrients can be recommended for the management of the disease.

  2. Nutrient concentration age dynamics of teak (Tectona grandis L.f.) plantations in Central America

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Moya, J.; Murillo, R.; Portuguez, E.; Fallas, J. L.; Rios, V.; Kottman, F.; Verjans, J. M.; Mata, R.; Alvarado, A.

    2013-05-01

    Aim of study. Appropriate knowledge regarding teak (Tectona grandis L.f.) nutrition is required for a better management of the plantations to attain high productivity and sustainability. This study aims to answer the following questions: How can it be determined if a teak tree suffers a nutrient deficiency before it shows symptoms? Are nutrient concentration decreases in older trees associated with age-related declines in forest productivity? Area of study. Costa Rica and Panama. Material and Methods. Nutrient concentration in different tree tissues (bole, bark, branches and foliage) were measured at different ages using false-time-series in 28 teak plantations Research highlights. Foliar N concentration decreases from 2.28 in year 1 to 1.76% in year 19. Foliar Mg concentration increases from 0.23 in year 1 to 0.34% in year 19. The foliar concentrations of the other nutrients are assumed to be constant with tree age: 1.33% Ca, 0.88% K, 0.16% P, 0.12% S, 130 mg kg{sup -}1 Fe, 43 mg kg{sup -}1 Mn, 11 mg kg{sup -}1 Cu, 32 mg kg{sup -}1 Zn and 20 mg kg{sup -}1 B. The nutrient concentration values showed can be taken as a reference to evaluate the nutritional status of similar teak plantations in the region. The concentrations of K, Mg and N could be associated with declines in teak plantation productivity as the plantation becomes older. Whether age-related changes in nutrient concentrations are a cause or a consequence of age-related declines in productivity is an issue for future research with the aim of achieving higher growth rates throughout the rotation period. (Author) 35 refs.

  3. Increased nutrient concentrations in Lake Erie tributaries influenced by greenhouse agriculture.

    Science.gov (United States)

    Maguire, Timothy J; Wellen, Christopher; Stammler, Katie L; Mundle, Scott O C

    2018-08-15

    Greenhouse production of vegetables is a growing global trade. While greenhouses are typically captured under regulations aimed at farmland, they may also function as a point source of effluent. In this study, the cumulative impacts greenhouse effluents have on riverine macronutrient and trace metal concentrations were examined. Water samples were collected Bi-weekly for five years from 14 rivers in agriculturally dominated watersheds in southwestern Ontario. Nine of the watersheds contained greenhouses with their boundaries. Greenhouse influenced rivers had significantly higher concentrations of macronutrients (nitrogen, phosphorus, and potassium) and trace metals (copper, molybdenum, and zinc). Concentrations within greenhouse influenced rivers appeared to decrease over the 5-year study while concentrations within non-greenhouse influenced river remained constant. The different temporal pattern between river types was attributed to increased precipitation during the study period. Increases in precipitation diluted concentrations in greenhouse influenced rivers; however, non-influenced river runoff proportionally increased nutrient mobility and flow, stabilizing the observed concentrations of non-point sources. Understanding the dynamic nature of environmental releases of point and non-point sources of nutrients and trace metals in mixed agricultural systems using riverine water chemistry is complicated by changes in climatic conditions, highlighting the need for long-term monitoring of nutrients, river flows and weather data in assessing these agricultural sectors. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Ultraviolet-B radiation and nitrogen affect nutrient concentrations and the amount of nutrients acquired by above-ground organs of maize.

    Science.gov (United States)

    Correia, Carlos M; Coutinho, João F; Bacelar, Eunice A; Gonçalves, Berta M; Björn, Lars Olof; Moutinho Pereira, José

    2012-01-01

    UV-B radiation effects on nutrient concentrations in above-ground organs of maize were investigated at silking and maturity at different levels of applied nitrogen under field conditions. The experiment simulated a 20% stratospheric ozone depletion over Portugal. At silking, UV-B increased N, K, Ca, and Zn concentrations, whereas at maturity Ca, Mg, Zn, and Cu increased and N, P and Mn decreased in some plant organs. Generally, at maturity, N, Ca, Cu, and Mn were lower, while P, K, and Zn concentrations in stems and nitrogen-use efficiency (NUE) were higher in N-starved plants. UV-B and N effects on shoot dry biomass were more pronounced than on nutrient concentrations. Nutrient uptake decreased under high UV-B and increased with increasing N application, mainly at maturity harvest. Significant interactions UV-B x N were observed for NUE and for concentration and mass of some elements. For instance, under enhanced UV-B, N, Cu, Zn, and Mn concentrations decreased in leaves, except on N-stressed plants, whereas they were less affected by N nutrition. In order to minimize nutritional, economical, and environmental negative consequences, fertiliser recommendations based on element concentration or yield goals may need to be adjusted.

  5. Ultraviolet-B Radiation and Nitrogen Affect Nutrient Concentrations and the Amount of Nutrients Acquired by Above-Ground Organs of Maize

    Directory of Open Access Journals (Sweden)

    Carlos M. Correia

    2012-01-01

    Full Text Available UV-B radiation effects on nutrient concentrations in above-ground organs of maize were investigated at silking and maturity at different levels of applied nitrogen under field conditions. The experiment simulated a 20% stratospheric ozone depletion over Portugal. At silking, UV-B increased N, K, Ca, and Zn concentrations, whereas at maturity Ca, Mg, Zn, and Cu increased and N, P and Mn decreased in some plant organs. Generally, at maturity, N, Ca, Cu, and Mn were lower, while P, K, and Zn concentrations in stems and nitrogen-use efficiency (NUE were higher in N-starved plants. UV-B and N effects on shoot dry biomass were more pronounced than on nutrient concentrations. Nutrient uptake decreased under high UV-B and increased with increasing N application, mainly at maturity harvest. Significant interactions UV-B x N were observed for NUE and for concentration and mass of some elements. For instance, under enhanced UV-B, N, Cu, Zn, and Mn concentrations decreased in leaves, except on N-stressed plants, whereas they were less affected by N nutrition. In order to minimize nutritional, economical, and environmental negative consequences, fertiliser recommendations based on element concentration or yield goals may need to be adjusted.

  6. Mapping of trophic states based on nutrients concentration and phytoplankton abundance in Jatibarang Reservoir

    Science.gov (United States)

    Rudiyanti, Siti; Anggoro, Sutrisno; Rahman, Arif

    2018-02-01

    Jatibarang Reservoir is one of the Indonesian Reservoirs, which used for human activities such as tourism and agriculture. These activities will provide input of organic matter and nutrients into the water. These materials will impact water quality and eutrophication process. Eutrophication is the water enrichment by nutrients, especially nitrogen and phosphorus which can promote the growth of phytoplankton. Some indicators of eutrophication are increasing nutrients, trophic states, and change of phytoplankton composition. The relationship between water quality and phytoplankton community can be used as an indicator of trophic states in Jatibarang Reservoir. The aim of this study was to analyze the effect of nutrients concentration and phytoplankton abundance to the trophic states and mapping trophic states based on nutrients concentration and phytoplankton in Jatibarang Reservoir. This study was conducted in June and July 2017 at 9 stations around Jatibarang Reservoir. The results showed that average concentration of nitrate, phosphate, and chlorophyll-a in Jatibarang Reservoir was 0.69 mg/L, 0.27 mg/L, and 1.66 mg/m3, respectively. The phytoplankton abundance ranged 16-62,200 cells/L, consists of 21 genera of four classes, i.e. Chlorophyceae, Cyanophyceae, Bacillariophyceae, and Dinophyceae. Cyanophyceae was a dominant phytoplankton group based on the composition of abundance (>80%). High nutrient concentrations and phytoplankton dominated by Anabaena (Cyanophyceae) which indicated that the waters in Jatibarang Reservoir were eutrophic.

  7. Detecting terrestrial nutrient limitation: a global meta-analysis of foliar nutrient concentrations after fertilization

    Directory of Open Access Journals (Sweden)

    Rebecca eOstertag

    2016-03-01

    Full Text Available Examining foliar nutrient concentrations after fertilization provides an alternative method for detecting nutrient limitation of ecosystems, which is logistically simpler to measure than biomass change. We present a meta-analysis of response ratios of foliar nitrogen and phosphorus (RRN, RRP after addition of fertilizer of nitrogen (N, phosphorus (P, or the two elements in combination, in relation to climate, ecosystem type, life form, family, and methodological factors. Results support other meta-analyses using biomass, and demonstrate there is strong evidence for nutrient limitation in natural communities. However, because N fertilization experiments greatly outnumber P fertilization trials, it is difficult to discern the absolute importance of N vs. P vs. co-limitation across ecosystems. Despite these caveats, it is striking that results did not follow conventional wisdom that temperate ecosystems are N-limited and tropical ones are P-limited. In addition, the use of ratios of N-to-P rather than response ratios also are a useful index of nutrient limitation, but due to large overlap in values, there are unlikely to be universal cutoff values for delimiting N vs. P limitation. Differences in RRN and RRP were most significant across ecosystem types, plant families, life forms, and between competitive environments, but not across climatic variables.

  8. Development of an automated flow injection analysis system for determination of phosphate in nutrient solutions.

    Science.gov (United States)

    Karadağ, Sevinç; Görüşük, Emine M; Çetinkaya, Ebru; Deveci, Seda; Dönmez, Koray B; Uncuoğlu, Emre; Doğu, Mustafa

    2018-01-25

    A fully automated flow injection analysis (FIA) system was developed for determination of phosphate ion in nutrient solutions. This newly developed FIA system is a portable, rapid and sensitive measuring instrument that allows on-line analysis and monitoring of phosphate ion concentration in nutrient solutions. The molybdenum blue method, which is widely used in FIA phosphate analysis, was adapted to the developed FIA system. The method is based on the formation of ammonium Mo(VI) ion by reaction of ammonium molybdate with the phosphate ion present in the medium. The Mo(VI) ion then reacts with ascorbic acid and is reduced to the spectrometrically measurable Mo(V) ion. New software specific for flow analysis was developed in the LabVIEW development environment to control all the components of the FIA system. The important factors affecting the analytical signal were identified as reagent flow rate, injection volume and post-injection flow path length, and they were optimized using Box-Behnken experimental design and response surface methodology. The optimum point for the maximum analytical signal was calculated as 0.50 mL min -1 reagent flow rate, 100 µL sample injection volume and 60 cm post-injection flow path length. The proposed FIA system had a sampling frequency of 100 samples per hour over a linear working range of 3-100 mg L -1 (R 2  = 0.9995). The relative standard deviation (RSD) was 1.09% and the limit of detection (LOD) was 0.34 mg L -1 . Various nutrient solutions from a tomato-growing hydroponic greenhouse were analyzed with the developed FIA system and the results were found to be in good agreement with vanadomolybdate chemical method findings. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  9. Influence of light presence and biomass concentration on nutrient kinetic removal from urban wastewater by Scenedesmus obliquus.

    Science.gov (United States)

    Ruiz, J; Arbib, Z; Alvarez-Díaz, P D; Garrido-Pérez, C; Barragán, J; Perales, J A

    2014-05-20

    This work was aimed at studying the effect of light-darkness and high-low biomass concentrations in the feasibility of removing nitrogen and phosphorus from urban treated wastewater by the microalga Scenedesmus obliquus. Laboratory experiments were conducted in batch, where microalgae were cultured under different initial biomass concentrations (150 and 1500mgSSl(-1)) and light conditions (dark or illuminated). Nutrient uptake was more dependent on internal nutrient content of the biomass than on light presence or biomass concentration. When a maximum nitrogen or phosphorus content in the biomass was reached (around 8% and 2%, respectively), the removal of that nutrient was almost stopped. Biomass concentration affected more than light presence on the nutrient removal rate, increasing significantly with its increase. Light was only required to remove nutrients when the maximum nutrient storage capacity of the cells was reached and further growth was therefore needed. Residence times to maintain a stable biomass concentration, avoiding the washout of the reactor, were much higher than those needed to remove the nutrients from the wastewater. This ability to remove nutrients in the absence of light could lead to new configurations of reactors aimed to wastewater treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Bacterial Shifts in Nutrient Solutions Flowing Through Biofilters Used in Tomato Soilless Culture.

    Science.gov (United States)

    Renault, David; Déniel, Franck; Vallance, Jessica; Bruez, Emilie; Godon, Jean-Jacques; Rey, Patrice

    2017-11-25

    In soilless culture, slow filtration is used to eliminate plant pathogenic microorganisms from nutrient solutions. The present study focused on the characterization and the potential functions of microbial communities colonizing the nutrient solutions recycled on slow filters during a whole cultivation season of 7 months in a tomato growing system. Bacterial microflora colonizing the solutions before and after they flew through the columns were studied. Two filters were amended with Pseudomonas putida (P-filter) or Bacillus cereus strains (B-filter), and a third filter was a control (C-filter). Biological activation of filter unit through bacterial amendment enhanced very significantly filter efficacy against plant potential pathogens Pythium spp. and Fusarium oxysporum. However, numerous bacteria (10 3 -10 4  CFU/mL) were detected in the effluent solutions. The community-level physiological profiling indicated a temporal shift of bacterial microflora, and the metabolism of nutrient solutions originally oriented towards carbohydrates progressively shifted towards degradation of amino acids and carboxylic acids over the 7-month period of experiment. Single-strand conformation polymorphism fingerprinting profiles showed that a shift between bacterial communities colonizing influent and effluent solutions of slow filters occurred. In comparison with influent, 16S rDNA sequencing revealed that phylotype diversity was low in the effluent of P- and C-filters, but no reduction was observed in the effluent of the B-filter. Suppressive potential of solutions filtered on a natural filter (C-filter), where the proportion of Proteobacteria (α- and β-) increased, whereas the proportion of uncultured candidate phyla rose in P- and B-filters, is discussed.

  11. Can We Manage Nonpoint-Source Pollution Using Nutrient Concentrations during Seasonal Baseflow?

    Directory of Open Access Journals (Sweden)

    James A. McCarty

    2016-05-01

    Full Text Available Nationwide, a substantial amount of resources has been targeted toward improving water quality, particularly focused on nonpoint-source pollution. This study was conducted to evaluate the relationship between nutrient concentrations observed during baseflow and runoff conditions from 56 sites across five watersheds in Arkansas. Baseflow and stormflow concentrations for each site were summarized using geometric mean and then evaluated for directional association. A significant, positive correlation was found for NO–N, total N, soluble reactive P, and total P, indicating that sites with high baseflow concentrations also had elevated runoff concentrations. Those landscape factors that influence nutrient concentrations in streams also likely result in increased runoff, suggesting that high baseflow concentrations may reflect elevated loads from the watershed. The results highlight that it may be possible to collect water-quality data during baseflow to help define where to target nonpoint-source pollution best management practices within a watershed.

  12. Relation of nutrient concentrations, nutrient loading, and algal production to changes in water levels in Kabetogama Lake, Voyageurs National Park, northern Minnesota, 2008-09

    Science.gov (United States)

    Christensen, Victoria G.; Maki, Ryan P.; Kiesling, Richard L.

    2011-01-01

    Nutrient enrichment has led to excessive algal growth in Kabetogama Lake, Voyageurs National Park, northern Minnesota. Water- and sediment-quality data were collected during 2008-09 to assess internal and external nutrient loading. Data collection was focused in Kabetogama Lake and its inflows, the area of greatest concern for eutrophication among the lakes of Voyageurs National Park. Nutrient and algal data were used to determine trophic status and were evaluated in relation to changes in Kabetogama Lake water levels following changes to dam operation starting in 2000. Analyses were used to estimate external nutrient loading at inflows and assess the potential contribution of internal phosphorus loading. Kabetogama Lake often was mixed vertically, except for a few occasionally stratified areas, including Lost Bay in the northeastern part of Kabetogama Lake. Stratification, combined with larger bottom-water nutrient concentrations, larger sediment phosphorus concentrations, and estimated phosphorus release rates from sediment cores indicate that Lost Bay may be one of several areas that may be contributing substantially to internal loading. Internal loading is a concern because nutrients may cause excessive algal growth including potentially toxic cyanobacteria. The cyanobacterial hepatotoxin, microcystin, was detected in 7 of 14 cyanobacterial bloom samples, with total concentrations exceeding 1.0 microgram per liter, the World Health Organization's guideline for finished drinking water for the congener, microcystin-LR. Comparisons of the results of this study to previous studies indicate that chlorophyll-a concentrations and trophic state indices have improved since 2000, when the rules governing dam operation changed. However, total-phosphorus concentrations have not changed significantly since 2000.

  13. Nutrient concentrations in a Littorella uniflora community at higher CO2 concentrations and reduced light intensities

    DEFF Research Database (Denmark)

    Andersen, T.; Pedersen, O.; Andersen, F. Ø.

    2005-01-01

    laboratory experiments with isoetid vegetation (Littorella uniflora) where water column CO2 and light could be manipulated in order to test whether (i) light and CO2 availability affect nutrient concentrations in isoetid vegetation, and (ii) if changes in light and CO2 climate affect fluxes of inorganic...... nitrogen (N) and phosphorus (P) from sediment to water column, which potentially could result in increased growth of epiphytic algae. 3. The results showed that the standing stocks of phosphorus and nitrogen in the L. uniflora vegetation were significantly influenced by CO2 concentration and light...... intensity. Both standing stocks of P and N were significantly higher in the mesocosm treatments with high CO2 concentration than in those at low CO2 concentration. Similarly, standing stocks of P and N enhanced with increasing light intensity. 4. Measurements of nutrient fluxes both in the field...

  14. Growth and yield of summer squash: effect of the ionic concentration of nutrient solutionCrescimento e produtividade da abobrinha italiana: efeito da concentração iônica da solução nutritiva

    Directory of Open Access Journals (Sweden)

    Tiago Zanatta Aumonde

    2011-07-01

    Full Text Available With the objective of evaluating the effect of different ionic concentrations of the nutrient solution on growth of summer squash cultivated in raw rice husk substrate with leaching recirculation, two experiments were conducted in two crop-seasons: spring-summer of 2005 and summer-autumn of 2006, in Pelotas, RS. Four ionic concentrations of the nutrient solution (based on electrical conductivity - EC were studied: 1.3; 1.7; 2.1 and 4.2 dS m-1. Crop growth was determinated by accumulated dry mass production and partitioning among the different above-ground plant organs (leafs, stem and fruits at the end of the crop-seasons. Fruit yield was also evaluated. The obtained results indicate that ionic concentrations equal or lower than 1.7 dS m-1 were limiting for proper growth and yield of the crop. The effect of high ionic concentration of the nutrient solution (above 2.1 dS m-1 on dry mass production and partitioning varied according to the crop-season. The lower solar radiation availability of the summer-autumn crop season minimized the effects of the different concentrations of nutrient solution on dry mass production and partitioning to the fruits, as well as on the yield. The fruits comprised from 28 to 52% of the total above-ground dry mass production. Fruits represented the largest sink of assimilates of the plant only at 2.1 dS m-1 ionic concentration of the nutrient solution and in crescent solar radiation availability condition (spring-summer. According the mathematics models, the electrical conductivity that maximizes dry mass production and yield is approximately 3.0 dS m-1 for both crop-seasons.Com o objetivo de avaliar o efeito de diferentes concentrações iônicas da solução nutritiva sobre o crescimento e a produtividade da abobrinha italiana cultivada em substrato de casca de arroz in natura com recirculação dos lixiviados, foram realizados dois experimentos em duas épocas de cultivo: primavera-verão de 2005 e verão-outono de

  15. Spectral Quantitation Of Hydroponic Nutrients

    Science.gov (United States)

    Schlager, Kenneth J.; Kahle, Scott J.; Wilson, Monica A.; Boehlen, Michelle

    1996-01-01

    Instrument continuously monitors hydroponic solution by use of absorption and emission spectrometry to determine concentrations of principal nutrients, including nitrate, iron, potassium, calcium, magnesium, phosphorus, sodium, and others. Does not depend on extraction and processing of samples, use of such surrograte parameters as pH or electrical conductivity for control, or addition of analytical reagents to solution. Solution not chemically altered by analysis and can be returned to hydroponic process stream after analysis.

  16. Decadal and seasonal trends of nutrient concentration and export from highly managed coastal catchments.

    Science.gov (United States)

    Wan, Yongshan; Wan, Lei; Li, Yuncong; Doering, Peter

    2017-05-15

    Understanding anthropogenic and hydro-climatic influences on nutrient concentrations and export from highly managed catchments often necessitates trend detection using long-term monitoring data. This study analyzed the temporal trend (1979-2014) of total nitrogen (TN) and total phosphorus (TP) concentrations and export from four adjacent coastal basins in south Florida where land and water resources are highly managed through an intricate canal network. The method of integrated seasonal-trend decomposition using LOESS (LOcally weighted regrESSion) was employed for trend detection. The results indicated that long-term trends in TN and TP concentrations (increasing/decreasing) varied with basins and nutrient species, reflecting the influence of basin specific land and water management practices. These long-term trends were intervened by short-term highs driven by high rainfall and discharges and lows associated with regional droughts. Seasonal variations in TP were more apparent than for TN. Nutrient export exhibited a chemostatic behavior for TN from all the basins, largely due to the biogenic nature of organic N associated with the ubiquity of organic materials in the managed canal network. Varying degrees of chemodynamic export was present for TP, reflecting complex biogeochemical responses to the legacy of long-term fertilization, low soil P holding capacity, and intensive stormwater management. The anthropogenic and hydro-climatic influences on nutrient concentration and export behavior had great implications in nutrient loading abatement strategies for aquatic ecosystem restoration of the downstream receiving waterbody. Published by Elsevier Ltd.

  17. Symptoms of nutritional deficiencies in neem plants cultivated in nutrient solution

    Directory of Open Access Journals (Sweden)

    Ronnky Chaell Braga da Silva

    2011-03-01

    Full Text Available The planting of forest species is an activity that, besides introducing new exotic types of plants, can lessen the environmental impacts resulting from extractivism. Nevertheless, such success depends, upon other factors, on the knowledge of the nutritional needs of the species to be used. This study intended to check the typical symptoms of nutritional deficiency of macronutrients in the culture of Neem, through the visual observation of the plants. The experiment was carried out in a greenhouse at the College of Agronomy and Veterinary Medicine (FAMEV of the Federal University of Mato Grosso (UFMT in Cuiabá/MT, and it was set up in randomized blocks, with seven treatments and three repetitions. Each experimental unit was represented by a plastic vase, two liters capacity. The treatments used were: complete nutritive solution and solution with the omission of the following nutrients: -N, -P, -K, -Ca, -Mg and -S. It was ascertained that the visual symptoms of nutrient deficiency were, as a general rule, of easy characterization except for the treatment with omission of sulphur. Therefore, the omission of macronutrients decreases the production of total dry matter of the Neem plants, except for the omission of the S nutrient.

  18. Distribution and emission of oxamyl in a rockwool cultivation system with open drainage of the nutrient solution

    NARCIS (Netherlands)

    Runia, W.T.; Dekker, A.; Houx, N.W.H.

    1995-01-01

    On a 1.8 ha eggplant nursery with open drainage of the excess of nutrient solution the distribution of oxamyl was measured after it had been added to the nutrient solution. When it was applied via injection at a tap of a section, the distribution was more uniform than when applied via the central

  19. Excess nutrients in hydroponic solutions alter nutrient content of rice, wheat, and potato

    Science.gov (United States)

    McKeehen, J. D.; Mitchell, C. A.; Wheeler, R. M.; Bugbee, B.; Nielsen, S. S.

    1996-01-01

    Environment has significant effects on the nutrient content of field-grown crop plants. Little is known, however, about compositional changes caused by controlled environments in which plants receive only artificial radiation and soilless, hydroponic culture. This knowledge is essential for developing a safe, nutritious diet in a Controlled Ecological Life-Support System (CELSS). Three crops that are candidates for inclusion in a CELSS (rice, wheat, and white potato) were grown both in the field and in controlled environments where the hydroponic nutrient solution, photosynthetic photon flux (PPF), and CO2 level were manipulated to achieve rapid growth rates. Plants were harvested at maturity, separated into discrete parts, and dried prior to analysis. Plant materials were analyzed for proximate composition (protein, fat, ash, and carbohydrate), total nitrogen (N), nitrate, minerals, and amino-acid composition. The effect of environment on nutrient content varied by crop and plant part. Total N and nonprotein N (NPN) contents of plant biomass generally increased under controlled-environment conditions compared to field conditions, especially for leafy plant parts and roots. Nitrate levels were increased in hydroponically-grown vegetative tissues, but nitrate was excluded from grains and tubers. Mineral content changes in plant tissue included increased phosphorus and decreased levels of certain micronutrient elements under controlled-environment conditions. These findings suggest that cultivar selection, genetic manipulation, and environmental control could be important to obtain highly nutritious biomass in a CELSS.

  20. Influence of harvest managements on biomass nutrient concentrations and removal rates of festulolium and tall fescue from a poorly drained nutrient-rich fen peatland

    DEFF Research Database (Denmark)

    Kandel, Tanka; Elsgaard, Lars; Lærke, Poul Erik

    2017-01-01

    This study was designed to show the effects of harvest time and frequency on biomass nutrient concentrations (total ash, N, P, K, Ca, Mg, Fe, Mn, Cu and Zn) as well as total nutrient removal potential by festulolium and tall fescue cultivated on a nutrient-rich fen peatland. The harvest managemen...

  1. NUTRIENTS CONCENTRATION AND RETRANSLOCATION IN THE Pinus taeda L. NEEDLES

    Directory of Open Access Journals (Sweden)

    Márcio Viera

    2010-03-01

    Full Text Available Aiming at evaluating nutrients concentration and retranslocation in the Pinus taeda L. needles, this study was developed in two stands, in native grass area and in second rotation area, with same species and same age (7.5 years old in Cambará do Sul, RS. The needles were collected in plants in four orthogonal points (South, North, East and West, sampled new needles, mature needles and old needles. The material was dried in a stove, milled and chemically analyzed (macro and micronutrients. The concentrations of N, P, K, B, Cu and Zn had decreased, of Ca, Fe and Mn increased, and the Mg and S have remained constant with the age of the needles. The retranslocation rate (old-new needles was more than 50% for most nutrients, except for Mn and Fe, showed that cumulative effect and the Ca reference element.

  2. Nutritional disorder of lettuce cv. Veronica in nutrient solution with suppressed macronutrients

    Directory of Open Access Journals (Sweden)

    Thiago Batista Firmato de Almeida

    2011-06-01

    Full Text Available Lettuce is the most popular of the leafy vegetables. It is known worldwide and its consumption occurs mainly in the natural form. The objective was to evaluate the effect of macronutrient omission on the growth and nutritional status of the lettuce cv. Veronica, and to describe the visual symptoms of nutritional deficiency. The treatments complete consisted of the solution and the individual omission of N, P, K, Ca, Mg and S, under a completely randomized design with three replications. Plants were grown in Hoagland & Arnon, in pots (8L. At 56 days after transplant we evaluated plant height, leaf number, leaf area, SPAD index, dry matter of shoots, roots and whole plant, levels of macronutrients in shoots and roots, and the nature of nutritional disorders. The omission of nutrients affected the growth variables. The nutrients found in lettuce plants from nutrient solution and the complete omission in the shoot were, respectively, N= 23.2 to 9.5, P= 5.4 to 1.3, K= 58,9 to 3.2, Ca= 12.1 to 3.6, Mg= 5.5 to 0.7 and S= 3.2 to 1.5g.kg-1. The omission of macronutrients caused quality losses, since it affected the nutrition of the vegetables and this resulted in morphological changes, reflected as symptoms of deficiency for each nutrient.

  3. Nutrient depletion from rhizosphere solution by maize grown in soil with long-term compost amendment

    Science.gov (United States)

    Improved understanding of rhizosphere chemistry will enhance our ability to model nutrient dynamics and on a broader scale, to develop effective management strategies for applied plant nutrients. With a controlled-climate study, we evaluated in situ changes in macro-nutrient concentrations in the rh...

  4. Solução nutritiva para produção de menta em hidroponia Nutrient solution for mint production in hydroponic solution

    Directory of Open Access Journals (Sweden)

    Dalva Paulus

    2008-03-01

    ,50 x 0,25 m pode ser recomendada para o cultivo hidropônico de Mentha arvensis.The mint (Mentha arvensis L. is an aromatic plant that produces essential oil with high menthol concentration. For the hydroponic cultivation of vegetables and fruits, a great number of recommended formulas exist; however, little information exists about hydroponic solutions for mint. The goal of this work was to evaluate a nutrient solution for the mint cultivation in hydroponic system. Two experiments were carried out from October to December, 2004. For the field experiment, transplants were obtained from cuttings and produced in organic mineral substrates (plantmax®. Later they were transplanted in seed beds of 5.00 m length and 1.00 m width, spacings of 0.60 x 0.30 m. For the hydroponic system NFT, seedlings were obtained from cuttings and planted in phenolic foam where they stayed during 18 days. After that, they were transplanted to a production canal. The experimental design was a 2x2 factorial (nutrient solution concentrations x spacings. The hydroponic solution with 100% concentration in transplant and 50% replacement when the electric condutivity decreased 50% of the initial value and 0.5 x 0.25 m spacings resulted in the highest concentration of essential oil (0.60 mL 100 g-1 fresh leaves, menthol (82,4% and total dry matter (45 g plant-1. In hydroponic system the yield of dry matter and content of essential oil was higher than under soil conditions 27 g planta-1 of dry matter, concentration oil 0.53 mL 100 g-1 and 64,43% of menthol. The hydroponic solution with 100% concentration in transplant and 50% replacement when the electric condutivity decreased 50% of the initial value and 0.5 x 0.25 m spacing can be recommended for the cultivation of mint in hydroponic solution.

  5. Relationships Between Land Use and Stream Nutrient Concentrations in a Highly Urbanized Tropical Region of Brazil: Thresholds and Riparian Zones.

    Science.gov (United States)

    Tromboni, F; Dodds, W K

    2017-07-01

    Nutrient enrichment in streams due to land use is increasing globally, reducing water quality and causing eutrophication of downstream fresh and coastal waters. In temperate developed countries, the intensive use of fertilizers in agriculture is a main driver of increasing nutrient concentrations, but high levels and fast rates of urbanization can be a predominant issue in some areas of the developing world. We investigated land use in the highly urbanized tropical State of Rio de Janeiro, Brazil. We collected total nitrogen, total phosphorus, and inorganic nutrient data from 35 independent watersheds distributed across the State and characterized land use at a riparian and entire watershed scales upstream from each sample station, using ArcGIS. We used regression models to explain land use influences on nutrient concentrations and to assess riparian protection relationships to water quality. We found that urban land use was the primary driver of nutrient concentration increases, independent of the scale of analyses and that urban land use was more concentrated in the riparian buffer of streams than in the entire watersheds. We also found significant thresholds that indicated strong increases in nutrient concentrations with modest increases in urbanization reaching maximum nutrient concentrations between 10 and 46% urban cover. These thresholds influenced calculation of reference nutrient concentrations, and ignoring them led to higher estimates of these concentrations. Lack of sewage treatment in concert with urban development in riparian zones apparently leads to the observation that modest increases in urban land use can cause large increases in nutrient concentrations.

  6. Effects of thermal discharges on the seasonal patterns of nutrient concentrations in brackish water

    International Nuclear Information System (INIS)

    Nitchals, D.

    1985-05-01

    Massiv quantities of water are used in power plant cooling systems, especially nuclear power plants, and are often returned to the donor ecosystem at significantly elevated temperatures. Few studies of the environmental effects of such a situation have looked extensively at the effects on nutrients in the water. The present study examined the effects of cooling water discharges from a nuclear power plant on the seasonal nutrient patterns within and outside a brackish water, research artificial lake, the 0.9 km 2 Biotest Basin on Sweden's east coast. The lack of ice cover in winter is the most apparent effect. In a portion of the lake with a relatively long water residence time, on the order of a few days, the vernal nutrient depletion of phosphate, nitrate, and nitrite apparently began sooner than outside the lake. Benthic influence on nutrient concentrations in the free water mass may be very significant in coastal areas receiving heat inputs. This study's data apparently support the conclusion by other researchers that phosphorus may be the nutrient limiting algal growth in the spring in this area of the central Baltic Sea. Determination of a nutrient budget for the Basin was unachievable because inlet and outlet nutrient concentrations were insufficiently different to override experimental variation. Implications for management of heat inputs to coastal ecosystems include avoidance of areas with high nutrient content, rich organic sediment, or poor flushing. (author)

  7. Managed nutrient reduction impacts on nutrient concentrations, water clarity, primary production, and hypoxia in a north temperate estuary

    Science.gov (United States)

    Oviatt, Candace; Smith, Leslie; Krumholz, Jason; Coupland, Catherine; Stoffel, Heather; Keller, Aimee; McManus, M. Conor; Reed, Laura

    2017-12-01

    Except for the Providence River and side embayments like Greenwich Bay, Narragansett Bay can no longer be considered eutrophic. In summer 2012 managed nitrogen treatment in Narragansett Bay achieved a goal of reducing effluent dissolved inorganic nitrogen inputs by over 50%. Narragansett Bay represents a small northeast US estuary that had been heavily loaded with sewage effluent nutrients since the late 1800s. The input reduction was reflected in standing stock nutrients resulting in a statistically significant 60% reduction in concentration. In the Providence River estuary, total nitrogen decreased from 100 μm to about 40 μm, for example. We tested four environmental changes that might be associated with the nitrogen reduction. System apparent production was significantly decreased by 31% and 45% in the upper and mid Bay. Nutrient reductions resulted in statistically improved water clarity in the mid and upper Bay and in a 34% reduction in summer hypoxia. Nitrogen reduction also reduced the winter spring diatom bloom; winter chlorophyll levels after nutrient reduction have been significantly lower than before the reduction. The impact on the Bay will continue to evolve over the next few years and be a natural experiment for other temperate estuaries that will be experiencing nitrogen reduction. To provide perspective we review factors effecting hypoxia in other estuaries with managed nutrient reduction and conclude that, as in Narragansett Bay, physical factors can be as important as nutrients. On a positive note managed nutrient reduction has mitigated further deterioration in most estuaries.

  8. Calagem em solos de várzea e a disponibilidade de nutrientes na solução do solo após o alagamento Liming in lowland soils and nutrient availability in soil solution after flooding

    Directory of Open Access Journals (Sweden)

    Leandro Souza da Silva

    2005-10-01

    mixed with different lime quantities: zero, ½ SMP to pH 5,5; 1 SMP to pH 5,5; and 1 SMP to pH 6,0. After 90 days of incubation, the samples were placed in plastic pots with a soil solution collector. After flooding, soil solution was collected at 2, 8, 15, 22, 28, 42 and 56 days and Fe, Ca, Mg, K e P concentrations were analyzed. After flooding, the Fe concentration was reduced, the Ca and Mg were increased, and the K and P concentrations were not changed by lime rates. The soil solution nutrient concentrations after liming were different among the three soils types.

  9. Nutrient Concentrations and Stable Isotopes of Runoff from a Midwest Tile-Drained Corn Field

    Science.gov (United States)

    Wilkins, B. P.; Woo, D.; Li, J.; Michalski, G. M.; Kumar, P.; Conroy, J. L.; Keefer, D. A.; Keefer, L. L.; Hodson, T. O.

    2017-12-01

    Tile drains are a common crop drainage device used in Midwest agroecosystems. While efficient at drainage, the tiles provide a quick path for nutrient runoff, reducing the time available for microbes to use nutrients (e.g., NO3- and PO43-) and reduce export to riverine systems. Thus, understanding the effects of tile drains on nutrient runoff is critical to achieve nutrient reduction goals. Here we present isotopic and concentration data collected from tile drain runoff of a corn field located near Monticello, IL. Tile flow samples were measured for anion concentrations and stable isotopes of H2O and NO3-, while precipitation was measured for dual isotopes of H2O. Results demonstrate early tile flow from rain events have a low Cl- concentration (60% contribution) in the beginning of the hydrograph. As flow continues H2O isotopic values reflect pre-event water (ground and soil water), and Cl- concentrations increase representing a greater influence by matrix flow (60-90% contribution). Nitrate concentrations change dramatically, especially during the growing season, and do not follow a similar trend as the conservative Cl-, often decreasing days before, which represents missing nitrate in the upper surface portion of the soil. Nitrate isotopic data shows significant changes in 15N (4‰) and 18O (4‰) during individual hydrological events, representing that in addition to plant uptake and leaching, considerate NO3- is lost through denitrification. It is notable, that throughout the season d15N and d18O of nitrate change significantly representing that seasonally, substantial denitrification occurs.

  10. Effects of macro nutrient concentration on biological N2 fixation by Azotobacter vinelandii ATCC 12837

    International Nuclear Information System (INIS)

    Liew Pauline Woan Ying; Nazalan Najimudin; Jong Bor Chyan; Latiffah Noordin; Khairuddin Abdul Rahim; Amir Hamzah Ahmad Ghazali

    2010-01-01

    The dynamic changes of biological N 2 fixation by Azotobacter vinelandii ATCC 12837 under the influence of various macro nutrients, specifically phosphorus (P) and potassium (K), was investigated. In this attempt, Oryza sativa L. var. MR 219 was used as the model plant. Results obtained showed changes in the biological N 2 fixation activities with different macro nutrient(s) manipulations. The research activity enables optimisation of macro nutrients concentration for optimal/ enhanced biological N 2 fixation by A. vinelandii ATCC 12837. (author)

  11. Processing recommendations for using low-solids digestate as nutrient solution for poly-ß-hydroxybutyrate production with Synechocystis salina.

    Science.gov (United States)

    Meixner, K; Fritz, I; Daffert, C; Markl, K; Fuchs, W; Drosg, B

    2016-12-20

    Within the last decades, environmental pollution with persistent plastics steadily increased; therefore the production of biodegradable materials like poly-ß-hydroxybutyrate (PHB) is essential. Currently, PHB is produced with heterotrophic bacteria from crops. This leads to competition with food and feed production, which can be avoided by using photoautotrophic cyanobacteria, as Synechocystis salina, synthesizing PHB from CO 2 at nutrient limitation. This study aims to increase the economic efficiency of PHB production with cyanobacteria by using nutrients from anaerobic digestate. First, growth and PHB production of S. salina in digestate fractions (supernatant and permeate, with/without precipitating agents) and dilutions thereof and then the scale-up (photobioreactor, 200 L working volume) were evaluated. With precipitated and centrifuged digestate diluted 1/3 the highest biomass (1.55gL -1 ) and PHB concentrations (95.4mgL -1 ), being 78% of those in mineral media, were achieved. In the photobioreactor-experiments biomass (1.63gL -1 ) and PHB concentrations (88.7mgL -1 ), being 79% and 72% of those in mineral medium, were reached, but in a cultivation time 10days longer than in mineral medium. The possibility to use digestate as sustainable and low cost nutrient solution for microalgae cultivation and photoautotrophic PHB production, instead of applying it on fields or processing it to achieve discharge limits, makes this application a highly valid option. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Influence of Phosphorus and Manganese Rats in Nutrient Solution on Mn-54 Uptake by Mango Plants

    International Nuclear Information System (INIS)

    Sharaf, A.N.

    2011-01-01

    A greenhouse experiment was designed using solution culture and Mn-54 to study the effect of P and Mn rates on absorption of Mn-54, its translocation and percentage using six month old mango seedlings (Hindi Bi-Sinara cv.). Rates of P in nutrient solution were zero, half, one and two strength i.e. 0, 1, 2 and 4 m M whereas Mn rates were 1, 2 and 3 strength i.e. 2, 4 and 6 μM. The prepared nutrient solutions were labelled with carrier free Mn-54. Total absorption of Mn-54 by mango roots from nutrient solution was highly increased by increasing Mn rates, moreover, increasing P rates in media tended to enhance Mn-54 absorption. Translocation and distribution pattern of absorbed Mn-54 followed, to a great extent, the same trend of total absorption of it but with different magnitude. In this concern, more than 90% (about 94%) of total absorption of Mn-54 was retained in root system, whereas about 4% and 2% was translocated in stems and leaves, respectively. Retained Mn in mango roots is considered a good source of Mn for supplying mango plants with it for long term during growing season.

  13. Monitoring Stream Nutrient Concentration Trends in a Mixed-Land-Use Watershed

    Science.gov (United States)

    Zeiger, S. J.; Hubbart, J. A.

    2014-12-01

    Mixed-land use watersheds are often a complex patchwork of forested, agricultural, and urban land-uses where differential land-use mediated non-point source pollution can significantly impact water quality. Stream nitrogen and phosphorus concentrations serve as important variables for quantifying land use effects on non-point source pollution in receiving waters and relative impacts on aquatic biota. The Hinkson Creek Watershed (HCW) is a representative mixed land use urbanizing catchment (231 km2) located in central Missouri, USA. A nested-scale experimental watershed study including five permanent hydroclimate stations was established in 2009 to provide quantitative understanding of multiple land use impacts on nutrient loading. Spectrophotometric analysis was used to quantify total inorganic nitrogen (TIN) and total phosphorus (TP as PO4) regimes. Results (2010 - 2013) indicate average nitrate (NO3-) concentration (mg/l) range of 0.28 to 0.46 mg/l, nitrite (NO2-) range of 0.02 to 0.03 mg/l, ammonia (NH3) ranged from 0.04 to 0.08 mg/l, and TP range of 0.26 to 0.39 mg/l. With n=858, NO3-, NO2-, NH3, and TP concentrations were significantly (CI=95%, p=0.00) higher in the subbasin with the greatest percent cumulative agricultural land use (57%). NH3 and TP concentrations were significantly (CI=95%, p=0.00) higher (with the exception of the agricultural subbasin) in the subbasin with the greatest percent cumulative urban land use (26%). Results from multiple regression analyses showed percent cumulative agricultural and urban land uses accounted for 85% and 96% of the explained variance in TIN loading (CI=95%, p=0.08) and TP loading (CI=95%, p=0.02), respectively, between gauging sites. These results improve understanding of agricultural and urban land use impacts on nutrient concentrations in mixed use watersheds of the Midwest and have implications for nutrient reduction programs in the Mississippi River Basin and hypoxia reductions in the Gulf of Mexico, USA.

  14. Wind-induced flow velocity effects on nutrient concentrations at Eastern Bay of Lake Taihu, China.

    Science.gov (United States)

    Jalil, Abdul; Li, Yiping; Du, Wei; Wang, Jianwei; Gao, Xiaomeng; Wang, Wencai; Acharya, Kumud

    2017-07-01

    Shallow lakes are highly sensitive to respond internal nutrient loading due to wind-induced flow velocity effects. Wind-induced flow velocity effects on nutrient suspension were investigated at a long narrow bay of large shallow Lake Taihu, the third largest freshwater lake in China. Wind-induced reverse/compensation flow and consistent flow field probabilities at vertical column of the water were measured. The probabilities between the wind field and the flow velocities provided a strong correlation at the surface (80.6%) and the bottom (65.1%) layers of water profile. Vertical flow velocity profile analysis provided the evidence of delay response time to wind field at the bottom layer of lake water. Strong wind field generated by the west (W) and west-north-west (WNW) winds produced displaced water movements in opposite directions to the prevailing flow field. An exponential correlation was observed between the current velocities of the surface and the bottom layers while considering wind speed as a control factor. A linear model was developed to correlate the wind field-induced flow velocity impacts on nutrient concentration at the surface and bottom layers. Results showed that dominant wind directions (ENE, E, and ESE) had a maximum nutrient resuspension contribution (nutrient resuspension potential) of 34.7 and 43.6% at the surface and the bottom profile layers, respectively. Total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP) average concentrations were 6.38, 1.5, and 0.03 mg/L during our field experiment at Eastern Bay of Lake Taihu. Overall, wind-induced low-to-moderate hydrodynamic disturbances contributed more in nutrient resuspension at Eastern Bay of Lake Taihu. The present study can be used to understand the linkage between wind-induced flow velocities and nutrient concentrations for shallow lakes (with uniform morphology and deep margins) water quality management and to develop further models.

  15. The Effects of Different Isocaloric Oral Nutrient Solutions on Psychophysical, Metabolic, Cognitive, and Olfactory Function in Young Male Subjects

    Directory of Open Access Journals (Sweden)

    Stephan Bachlechner

    2017-11-01

    Full Text Available Food intake influences human cognition, olfaction, hunger, and food craving. However, little research has been done in this field to elucidate the effects of different nutrients. Thus, the goal of our study was to investigate the effects of oral ingestion of different nutrient solutions on olfactory, cognitive, metabolic and psychophysical function. Twenty healthy men participated in our study employing a double-blind, cross-over, repeated measurement design. Participants were tested on four different study days. Each day participants received, in randomized order, one of three isocaloric (protein, carbohydrate or fat 600 kcal, 1,500 mL solutions or a placebo. Olfactory and cognitive tests (monitoring only were conducted three times, i.e., 60 min before the beginning of nutrient intake, following oral ingestion of the solution and 60, and 240 min after. Psychophysical and metabolic function tests (active grehlin, desacyl ghrelin, insulin, glucagon, glucose, triglyceride, urea were performed 7 times on each examination day (observation period: −60 min, 0 = solution intake, +60, +120, +180, +240, and +300 min. Ratings of hunger and food craving significantly differed over the observation period with lowest ratings following application of the protein solution. Highest ratings of craving were found following placebo intake. We further observed a significant positive correlation of active grehlin with hunger and fat, protein and sweets craving for each nutrient solution. Active grehlin significantly correlated with carbohydrate craving for carbohydrate and fat solution and with vegetable craving for fat solution only. Hunger hormone levels, hunger and food craving ratings demonstrated that the hierarchical order that appears in satiating efficiencies of isovolumetric-isocaloric ingested macronutrients is protein > fat > carbohydrate. Our study reveals that the type of nutrient exerts a significant influence on metabolic parameters, hunger and food

  16. The Effects of Different Isocaloric Oral Nutrient Solutions on Psychophysical, Metabolic, Cognitive, and Olfactory Function in Young Male Subjects.

    Science.gov (United States)

    Bachlechner, Stephan; Denzer-Lippmann, Melanie Y; Wielopolski, Jan; Fischer, Marie; Buettner, Andrea; Doerfler, Arndt; Schöfl, Christof; Münch, Gerald; Kornhuber, Johannes; Thürauf, Norbert

    2017-01-01

    Food intake influences human cognition, olfaction, hunger, and food craving. However, little research has been done in this field to elucidate the effects of different nutrients. Thus, the goal of our study was to investigate the effects of oral ingestion of different nutrient solutions on olfactory, cognitive, metabolic and psychophysical function. Twenty healthy men participated in our study employing a double-blind, cross-over, repeated measurement design. Participants were tested on four different study days. Each day participants received, in randomized order, one of three isocaloric (protein, carbohydrate or fat 600 kcal, 1,500 mL) solutions or a placebo. Olfactory and cognitive tests (monitoring only) were conducted three times, i.e., 60 min before the beginning of nutrient intake, following oral ingestion of the solution and 60, and 240 min after. Psychophysical and metabolic function tests (active grehlin, desacyl ghrelin, insulin, glucagon, glucose, triglyceride, urea) were performed 7 times on each examination day (observation period: -60 min, 0 = solution intake, +60, +120, +180, +240, and +300 min). Ratings of hunger and food craving significantly differed over the observation period with lowest ratings following application of the protein solution. Highest ratings of craving were found following placebo intake. We further observed a significant positive correlation of active grehlin with hunger and fat, protein and sweets craving for each nutrient solution. Active grehlin significantly correlated with carbohydrate craving for carbohydrate and fat solution and with vegetable craving for fat solution only. Hunger hormone levels, hunger and food craving ratings demonstrated that the hierarchical order that appears in satiating efficiencies of isovolumetric-isocaloric ingested macronutrients is protein > fat > carbohydrate. Our study reveals that the type of nutrient exerts a significant influence on metabolic parameters, hunger and food craving.

  17. Application of TXRF spectrometry and HPLC for the characterization of xylem saps of nickel contaminated cucumber plants grown in urea containing nutrient solutions

    International Nuclear Information System (INIS)

    Tatar, E.; Mihucz, V.G.; Varga, G.; Zaray, G.; Cseh, E.

    2000-01-01

    The total reflection X-ray fluorescence (TXRF) spectrometry was used to determine the elemental composition of xylem saps of cucumber plants grown in nutrient solutions having urea, as the sole nitrogen source and artificially contaminated with nickel(II) ions in concentration of 10 μM, which proved to be toxic for the plants. The saps of uncontaminated plants - grown at the same time with the contaminated ones - were also investigated. The collection of the samples was performed for 1 hour followed by two additional 30-minute-long time periods, thus three samples resulted for each group of plants. The TXRF measurements were performed using Ga as internal standard. For excitation, Mo tube was used and the integration time was 300 s. The nutrient heavy metals determined by the TXRF spectrometry in the saps were Fe, Mn and Zn in concentration range of ng/cm 3 . Two other nutrient elements, Ca and K were also determined and they were present in the samples in concentration of μg/cm 3 . The concentration of nickel in the saps originating from the contaminated plants, was approximately 1400 ng/cm 3 . The concentration of another nutrient heavy metal, Cu was determined by the graphite furnace atomic absorption (GF-AAS) spectrometry. Applying a reversed-phased HPLC method, the organic acids of the samples, citric, malic and fumaric acids were also quantified, their concentrations being also in the μg/cm 3 concentration range. Size exclusion chromatography (SEC) measurements were also performed in order to detect possible macromolecules of the saps. Both techniques, having low sample volume demand, were suitable to perform reliable measurements of the samples whose masses were between 0,9-2,5 g. Furthermore, the absence of the matrix effects is also an important advantage of the TXRF spectrometry that permits the direct analysis of the xylem saps. These investigations form part of our work focusing on the availability, accumulation and transport of heavy metals in

  18. Crescimento e produtividade do almeirão em concentrações de N total contendo NH4+ na solução nutritiva Growth and yield of chicory plants under total N concentrations containing NH4+ in the nutrient solution

    Directory of Open Access Journals (Sweden)

    Rodrigo dos Santos Godoi

    2007-08-01

    Full Text Available O crescimento e a produtividade do almeirão foram determinados em cultivo hidropônico fechado com cinco concentrações de N contendo NH4+ na solução nutritiva. As cultivares "Amarelo" e "Pão de Açúcar" foram semeadas diretamente em fileiras distanciadas de 0,05m, em uma camada de areia de 0,15m, distribuída sobre telhas de fibrocimento. Após a emergência, foi efetuado o desbaste, mantendo-se uma densidade de 1.600plantas m-2. Foi empregada uma solução nutritiva padrão com a composição de, em mmol L-1, 11,0 de NO3-; 1,5 de H2PO4-; 6,5 de SO4-2; 7,5 de Ca+2; 10,0 de K+ e 1,5 de Mg+2 e, em mg L-1, 0,42 de Mn; 0,26 de Zn; 0,05 de Cu; 0,50 de B; 0,04 de Mo, e 4,82 de Fe quelatizado. Os tratamentos foram constituídos por concentrações totais de N de 11,0 (T1; 16,0 (T2; 21,0 (T3; 26,0 (T4 e 31,0 (T5mmol L-1, contendo concentrações de NH4+ de, zero; 2,5; 5,0; 7,5 e 10,0mmol L-1, respectivamente. O delineamento experimental inteiramente casualizado foi empregado, com quatro repetições e parcelas subdivididas. Foram efetuadas colheitas aos 35, 59, 76 e 97 dias após a semeadura, mediante corte da parte aérea das plantas a 0,02m acima da superfície da areia, para determinar a matéria seca e fresca. A maior produtividade foi obtida com a solução nutritiva contendo 16mmol L-1 de N total e 2,5mmol L-1 de NH4+.Chicory plants, cv. Amarela and Pão de Açúcar, were hidroponically grown to determine growth and yield under five ammonium and nitrate N concentrations in the nutrient solution. Sowing was made in rows placed 0.05m apart, over a 0.15m deep sand growing bed supported by fibber cement tiles. After emergency, plants were thinned to a plant density of 1,600plants m-2. A standard nutrient solution was used, with the composition of, in mmol L-1, 11.0 de NO3-; 1.5 H2PO4-; 6.5 SO4-2; 7.5 Ca+2; 10.0 K+ and 1.5 Mg+2, and, in mg L-1, 0.42 Mn; 0.26 Zn; 0.05 Cu; 0.50 B; 0.04 Mo, and 4.82 chelated Fe. Treatments were total N

  19. Toxic metabolities of disulfoton: behavior in bean-seedlings, in soil, and in nutrient solution

    International Nuclear Information System (INIS)

    Andrea, M.M. de

    1986-10-01

    The absorption, translocation and degradation in bean-seedlings of three toxic metabolites of the pesticide 14 C- disulfoton from nutrient solution or three different types of Brazilian soils is studied. (M.A.C.) [pt

  20. Hydrothermal carbonization of glucose in saline solution: sequestration of nutrients on carbonaceous materials

    Directory of Open Access Journals (Sweden)

    Jessica Nover

    2016-02-01

    Full Text Available In this study, feasibility of selected nutrient sequestration during hydrothermal carbonization (HTC was tested for three different HTC temperatures (180, 230, and 300 °C. To study the nutrient sequestration in solid from liquid solution, sugar and salt solutions were chosen as HTC feedstock. Glucose was used as carbohydrate source and various salts e.g., ammonium hydrophosphate, potassium chloride, potassium sulfate, and anhydrous ferric chloride were used as source of nitrogen and phosphorus, potassium, and iron, respectively. Solid hydrochar was extensively characterized by means of elemental, ICP-OES, SEM-EDX, surface area, pore volume and size, and ATR-FTIR to determine nutrients’ sequestration as well as hydrochar quality variation with HTC temperatures. The spherical mesoporous hydrochars produced during HTC have low surface area in the range of 1.0–3.5 m2 g−1. Hydrochar yield was increased about 10% with the increase of temperature from 180 °C to 300 °C. Nutrient sequestration was also increased with HTC temperature. In fact, around 71, 31, and 23 wt% nitrogen, iron, and phosphorus were sequestered at 300 °C, respectively. Potassium sequestration was very low throughout the HTC and maximum 5.2% was observed in solid during HTC.

  1. Transposing Concentration-Discharge Curves onto Unmonitored Catchments to Estimate Seasonal Nutrient Loads

    Science.gov (United States)

    Minaudo, C.; Moatar, F.; Abbott, B. W.; Dupas, R.; Gascuel-Odoux, C.; Pinay, G.; Roubeix, V.; Danis, P. A.

    2017-12-01

    Many lakes and reservoirs in Europe suffer from severe eutrophication. Accurate quantification of nutrient loads are critical for effective mitigation measures, but this information is often unknown. For example, in France, only 50 out of 481 lakes and reservoirs have national monitoring allowing estimation of interannual nitrogen and phosphorus loads, and even these loads are computed from low-frequency data. To address this lack of data, we developed a straightforward method to predict seasonal loads in lake tributaries. First, we analyzed concentration-discharge (C-Q) curves in monitored catchments and identified slopes, intercepts, and coefficient of variation of the log(C)-log(Q) regressions determined for both low and high flows, separated by the median daily flow [Moatar et al., 2017]. Then, we used stepwise multiple linear regression models to empirically link the characteristics of C-Q curves with a set of catchment descriptors such as land use, lithology, morphology indices, climate, and hydrological indicators. Modeled C-Q relationships were then used to estimate annual and seasonal nutrient loads in nearby and similar unmonitored catchments. We implemented this approach on a large dataset from France where stream flow was surveyed daily and water quality (suspended solids, nitrate, total phosphorus, and orthophosphate concentrations) was measured on a monthly basis at 233 stations over the past 20 years in catchments from 10 to 3000 km². The concentration at the median daily flow (seen here as a metric of the general level of contamination in a catchment) was predicted with uncertainty ranging between 30 and 100 %, depending on the variable. C-Q slopes were predicted with large errors, but a sensitivity analysis was conducted to determine the impact of C-Q slopes uncertainties on computed annual and seasonal loads. This approach allows estimation of seasonal and annual nutrient loads and could be potentially implemented to improve protection and

  2. Linking river nutrient concentrations to land use and rainfall in a paddy agriculture-urban area gradient watershed in southeast China.

    Science.gov (United States)

    Xia, Yongqiu; Ti, Chaopu; She, Dongli; Yan, Xiaoyuan

    2016-10-01

    The effects of land use and land-use changes on river nutrient concentrations are not well understood, especially in the watersheds of developing countries that have a mixed land use of rice paddy fields and developing urban surfaces. Here, we present a three-year study of a paddy agricultural-urban area gradient watershed in southeast China. The annual anthropogenic nitrogen (N) input from the agricultural region to the urban region was high, yet the results showed that the monthly nutrient concentrations in the river were low in the rainy seasons. The nutrient concentrations decreased continuously as the river water passed through the traditional agriculture region (TAR; paddy rice and wheat rotation) and increased substantially in the city region (CR). The traditional agricultural reference region exported most of the nutrient loads at high flows (>1mmd(-1)), the intensified agricultural region (IAR, aquaculture and poultry farming) exported most of the nutrient loads at moderate flows (between 0.5 and 1mmd(-1)), and the CR reference area exported most of the nutrient loads under low to moderate flows. We developed a statistical model to link variations in the nutrient concentrations to the proportion of land-use types and rainfall. The statistical results showed that impervious surfaces, which we interpret as a proxy for urban activities including sewage disposal, were the most important drivers of nutrient concentrations, whereas water surfaces accounted for a substantial proportion of the nutrient sinks. Therefore, to efficiently reduce water pollution, sewage from urban areas must be addressed as a priority, although wetland restoration could also achieve substantial pollutant removal. Copyright © 2016. Published by Elsevier B.V.

  3. Nutrient management in substrate systems

    NARCIS (Netherlands)

    Sonneveld, C.; Voogt, W.

    2009-01-01

    Speaking about nutrient solutions in soilless cultivation, different solutions can be discerned. Originally, in soilless culture only one nutrient solution was taken into account, being the solution in the containers in which the plants were grown. Such solutions were intensively moved by air

  4. Zn availability in nutrient solutions for cucumber (Cucumis sativus L) in hydroponics as affected by Fe-chelates and pH

    NARCIS (Netherlands)

    Voogt, W.; Sonneveld, C.

    2017-01-01

    In soil-less culture systems Fe is usually supplied as chelate to ensure an adequate availability of this element. As chelates have affinity for many metal ions these chelates will interact with other cation nutrients in nutrient solutions. This affects the availability of Fe and other nutrients.

  5. Data to support "Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations & Biological Condition"

    Data.gov (United States)

    U.S. Environmental Protection Agency — Spreadsheets are included here to support the manuscript "Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition". This...

  6. Recycle of Inorganic Nutrients for Hydroponic Crop Production Following Incineration of Inedible Biomass

    Science.gov (United States)

    Bubenheim, David L.; Wignarajah, Kanapathipillai; Kliss, Mark H. (Technical Monitor)

    1996-01-01

    Recovery of resources from waste streams is essential for future implementation and reliance on a regenerative life support system. The major waste streams of concern are from human activities and plant wastes. Carbon, water and inorganics are the primary desired raw materials of interest. The goal of resource recovery is maintenance of product quality to insure support of reliable and predictable levels of life support function performance by the crop plant component. Further, these systems must be maintained over extended periods of time, requiring maintenance of nutrient solutions to avoid toxicity and deficiencies. Today, reagent grade nutrients are used to make nutrient solutions for hydroponic culture and these solutions are frequently changed during the life cycle or sometimes managed for only one crop life cycle. The focus of this study was to determine the suitability of the ash product following incineration of inedible biomass as a source of inorganic nutrients for hydroponic crop production. Inedible wheat biomass was incinerated and ash quality characterized. The incinerator ash was dissolved in adequate nitric acid to establish a consistent nitrogen concentration in all nutrient solution treatments. Four experimental nutrient treatments were included: control, ash only, ash supplemented to match control, and ash only quality formulated with reagent grade chemicals. When nutrient solutions are formulated using only ash following-incineration of inedible biomass, a balance in solution is established representing elemental retention following incineration and nutrient proportions present in the original biomass. The resulting solution is not identical to the control. This imbalance resulted in suppression of crop growth. When the ash is supplemented with nutrients to establish the same balance as in the control, growth is identical to the control. The ash appears to carry no phytotoxic materials. Growth in solution formulated with reagent grade chemicals

  7. Lignification in beech grown at elevated CO2 concentrations: interaction with nutrient availability and leaf maturation

    International Nuclear Information System (INIS)

    Blaschke, L; Forstreuter, M.; Sheppard, L. J.; Leith, K.; Murray, M. B.; Polle, A.

    2002-01-01

    Results of a study undertaken to investigate contradictory observations reported in the literature to the effect that growth in elevated carbon dioxide affects ontogeny, are discussed. Results of this study showed that seedlings grown at elevated carbon dioxide had nitrogen concentrations of about 15 per cent lower than seedlings grown in ambient carbon dioxide. Elevated carbon dioxide caused increased growth and biomass production in trees with a medium to high nutrient supply, but had no effect on growth of trees with a low nutrient supply rate. Because elevated carbon dioxide enhanced seedling growth in the high nutrient supply treatments, the total amount of lignin produced per seedling was higher in these treatments. Overall, the results suggest that carbon dioxide availability does not directly affect lignin concentrations, but affects them indirectly through the effects on or an interaction with nitrogen supply and growth. In seedlings, elevated carbon dioxide reduced lignin concentration on a dry mass basis, indicating diminished wood quality in a carbon dioxide-enriched atmosphere. 51 refs., 2 tabs., 5 figs

  8. Coupled Spatio-Temporal Patterns of Solute Transport, Metabolism and Nutrient Uptake in Streams

    Science.gov (United States)

    Kurz, M. J.; Schmidt, C.

    2017-12-01

    Slower flow velocities and longer residence times within stream transient storage (TS) zones facilitate interaction between solutes and microbial communities, potentially increasing local rates of metabolic activity. Multiple factors, including channel morphology and substrate, variable hydrology, and seasonal changes in biological and physical parameters, result in changes in the solute transport dynamics and reactivity of TS zones over time and space. These changes would be expected to, in turn, influence rates of whole-stream ecosystem functions such as metabolism and nutrient uptake. However, the linkages between solute transport and ecosystem functioning within TS zones, and the contribution of TS zones to whole-stream functioning, are not always so straight forward. This may be due, in part, to methodological challenges. In this study we investigated the influence of stream channel hydro-morphology and substrate type on reach (103 m) and sub-reach (102 m) scale TS and ecosystem functioning. Patterns in solute transport, metabolism and nitrate uptake were tracked from April through October in two contrasting upland streams using several methods. The two streams, located in the Harz Mountains, Germany, are characterized by differing size (0.02 vs. 0.3 m3/s), dominant stream channel substrate (bedrock vs. alluvium) and sub-reach morphology (predominance of pools, riffles and glides). Solute transport parameters and respiration rates at the reach and sub-reach scale were estimated monthly from coupled pulse injections of the reactive tracer resazurin (Raz) and conservative tracers uranine and salt. Raz, a weakly fluorescent dye, irreversibly transforms to resorufin (Rru) under mildly reducing conditions, providing a proxy for aerobic respiration. Daily rates of primary productivity, respiration and nitrate retention at the reach scale were estimated using the diel cycles in dissolved oxygen and nitrate concentrations measured by in-situ sensors. Preliminary

  9. Effect of molybdenum on the severity of toxicity symptoms in flax induced by an excess of either manganese, zinc, copper, nickel or cobalt in the nutrient solution

    Energy Technology Data Exchange (ETDEWEB)

    Millikan, C R

    1947-01-01

    The addition of molybdenum to solutions containing an excess of either manganese, zinc, copper, nickel or cobalt respectively, resulted in decreases in the severity of iron deficiency symptoms which normally occurred when flax was grown in solutions containing the same concentrations of any of these elements, but without molybdenum. The efficacy of molybdenum in this regard increased with increasing concentration up to 25 parts per million. However, concentrations of 0.5 to 2 parts per million of molybdenum had little effect on the severity of iron deficiency symptoms at the concentrations of heavy metals used. Molybdenum 5, 10 or 25 parts per million also retarded the date of appearance and reduced the severity of lower leaf necrosis which is another characteristic symptom of the presence of excess manganese (25 to 100 parts per million) in the nutrient solution. It is concluded that an essential function of molybdenum is intimately associated with the regulation of the deleterious effect of manganese, zinc, copper, nickel or cobalt on the physiological availability of iron to the plant. 46 references, 3 figures.

  10. Litter production and its nutrient concentration in some fuelwood trees grown on sodic soil

    Energy Technology Data Exchange (ETDEWEB)

    Garg, V.K. (National Botanical Research Inst., Lucknow (India))

    1992-01-01

    Litter production was estimated in 8-year-old tree plantations of Acacia nilotica, Prosopis juliflora, Dalbergia sisso, and Terminalia arjuna planted in a monoculture tree cropping system on sodic soils of Lucknow Division, India. Mean annual litter fall of these trees amounted to 5.9, 7.4, 5.0 and 5.4 t ha[sup -1], respectively. Irrespective of tree species, the leaf litter concentrations of N, K and Ca were greater than those of P and Mg. The concentration of nutrients in leaf tissues was negatively correlated for N and Ca, with the magnitude of leaf fall in D. sissoo, but was positively correlated for Ca and Mg in A. nilotica; no such correlations were found in P. juliflora and T. arjuna. The variations in the concentration of leaf litter nutrient did not appear to be species specific but depended on adverse edaphic properties including the fertility status of sodic soil. A. nilotica and P. juliflora with bimodal patterns of litter fall return greater amounts of nutrients to the soil surface than D. sissoo and T. arjuna which have unimodal patterns of litter fall. The study indicated the potential benefit of a mixed plantation system having variable leaf fall patterns among the planted trees so providing constant litter mulch to help in conserving soil moisture. (author).

  11. High nutrient concentration and temperature alleviated formation of large colonies of Microcystis: Evidence from field investigations and laboratory experiments.

    Science.gov (United States)

    Zhu, Wei; Zhou, Xiaohua; Chen, Huaimin; Gao, Li; Xiao, Man; Li, Ming

    2016-09-15

    Correlations between Microcystis colony size and environmental factors were investigated in Meiliang Bay and Gonghu Bay of Lake Taihu (China) from 2011 to 2013. Compared with Gonghu Bay, both nutrient concentrations and Microcystis colony sizes were greater in Meiliang Bay. The median colony size (D50: 50% of the total mass of particles smaller than this size) increased from April to August and then decreased until November. In both bays, the average D50 of Microcystis colonies were 500 μm) dominated in summer. The differences in colony size in Meiliang Bay and Gonghu Bay were probably due to horizontal drift driven by the prevailing south wind in summer. Redundancy analysis (RDA) of field data indicated that colony size was negatively related to nutrient concentrations but positively related to air temperature, suggesting that low nutrient concentrations and high air temperature promoted formation of large colonies. To validate the field survey, Microcystis colonies collected from Lake Taihu were cultured at different temperatures (15, 20, 25 and 30 °C) under high and low nutrient concentrations for 9 days. The size of Microcystis colonies significantly decreased when temperature was above 20 °C but had no significant change at 15 °C. The differences in temperature effects on colony formation shown from field and laboratory suggested that the larger colonies in summer were probably due to the longer growth period rather than the higher air temperature and light intensity. In addition, colony size decreased more significantly at high nutrient levels. Therefore, it could be concluded that high nutrient concentration and temperature may alleviate formation of large colonies of Microcystis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Influência do extrato pirolenhoso na calda de pulverização sobre o teor foliar de nutrientes em limoeiro 'Cravo' Effect of pyroligneous acid in the spraymg solutions on foliar nutrients content of 'Rangpur' lime

    Directory of Open Access Journals (Sweden)

    Marcelo Zanetti

    2004-12-01

    the following solutions: T0 = water; T1 = micronutrients solution without PA; T2 = micronutrients solution+ PA (1 cm³ dm-3; T3 = micronutrients solution + PA (2 cm³ dm-3; T4 = micronutrients solution + PA (5 cm³ dm-3; T5 = micronutrients solution + PA (10 cm³ dm-3. The micronutrient solutions were prepared by using sulphates of Cu, Fe, Mn and Zn (250 mg dm-3 of the elements, and boric acid (42.5 mg dm-3 of B. The experiment was set up on 0.280 dm³ conical containers, in growing media with no addition of micronutrients. The solutions were sprayed once, at 140 days after planting (DAP, when the plants were about 20 cm high. At the end of the experiment (160 DAP, dry mass of plants and concentrations of nutrients of aerial part and root system were evaluated. The presence of pyroligneous acid in the spraying solution did not affect B, Fe and Zn concentration in the leaves. However, increased Cu and Mn concentration for treatments containing PA at 10 cm³ dm-3 in the micronutrients solution. It was also observed that plants sprayed with solutions of PA (1 to 10 cm³ dm-3 + micronutrients showed lower Fe and higher Ca concentration on the root system.

  13. Monitoring TASCC Injections Using A Field-Ready Wet Chemistry Nutrient Autoanalyzer

    Science.gov (United States)

    Snyder, L. E.; Herstand, M. R.; Bowden, W. B.

    2011-12-01

    Quantification of nutrient cycling and transport (spiraling) in stream systems is a fundamental component of stream ecology. Additions of isotopic tracer and bulk inorganic nutrient to streams have been frequently used to evaluate nutrient transfer between ecosystem compartments and nutrient uptake estimation, respectively. The Tracer Addition for Spiraling Curve Characterization (TASCC) methodology of Covino et al. (2010) instantaneously and simultaneously adds conservative and biologically active tracers to a stream system to quantify nutrient uptake metrics. In this method, comparing the ratio of mass of nutrient and conservative solute recovered in each sample throughout a breakthrough curve to that of the injectate, a distribution of spiraling metrics is calculated across a range of nutrient concentrations. This distribution across concentrations allows for both a robust estimation of ambient spiraling parameters by regression techniques, and comparison with uptake kinetic models. We tested a unique sampling strategy for TASCC injections in which samples were taken manually throughout the nutrient breakthrough curves while, simultaneously, continuously monitoring with a field-ready wet chemistry autoanalyzer. The autoanalyzer was programmed to measure concentrations of nitrate, phosphate and ammonium at the rate of one measurement per second throughout each experiment. Utilization of an autoanalyzer in the field during the experiment results in the return of several thousand additional nutrient data points when compared with manual sampling. This technique, then, allows for a deeper understanding and more statistically robust estimation of stream nutrient spiraling parameters.

  14. Effects of watershed and riparian zone characteristics on nutrient concentrations in the River Scheldt Basin

    Directory of Open Access Journals (Sweden)

    J. Meynendonckx

    2006-01-01

    Full Text Available The relative influence of a set of watershed characteristics on surface water nutrient concentrations was examined in 173 watersheds within two subcatchments (Upper-Scheldt and Nete of the River Scheldt Basin (Flanders, Belgium. Each watershed was described by seasonal rainfall, discharge loading of point sources, morphological characteristics (area, average slope, drainage density, elongation, land use and soil properties (soil texture and drainage. Partial regression analysis revealed that soil drainage variables had the strongest influence on nutrient concentrations. Additional influence was exerted by land use and point source loading variables. Nitrate concentrations were positively correlated with effluent loadings coming from wastewater treatment plants and with the area of agricultural land. Phosphate concentrations were best explained by effluent loadings of industrial point sources and by the area of urban land. Land use close to the river was not a better predictor of nitrate and phosphate concentrations than land use away from the river. This suggests that the mediating impact of riparian zones is rather explained by the hydrologic pathways within the buffer strip.

  15. Ultraviolet-B Radiation and Nitrogen Affect Nutrient Concentrations and the Amount of Nutrients Acquired by Above-Ground Organs of Maize

    OpenAIRE

    Correia, Carlos M.; Coutinho, João F.; Bacelar, Eunice A.; Gonçalves, Berta M.; Björn, Lars Olof; Moutinho Pereira, José

    2012-01-01

    UV-B radiation effects on nutrient concentrations in above-ground organs of maize were investigated at silking and maturity at different levels of applied nitrogen under field conditions. The experiment simulated a 20% stratospheric ozone depletion over Portugal. At silking, UV-B increased N, K, Ca, and Zn concentrations, whereas at maturity Ca, Mg, Zn, and Cu increased and N, P and Mn decreased in some plant organs. Generally, at maturity, N, Ca, Cu, and Mn were lower, while P, K, and Zn con...

  16. Recovery of Nutrients from Biogas Digestate with Biochar and Clinoptilolite

    DEFF Research Database (Denmark)

    Kocatürk, Nazli Pelin

    in recovery of nutrients whose natural reserves are being depleted such as phosphorus and potassium. In this thesis I propose the use of sorbents i.e. biochar and clinoptilolite to concentrate nutrients and subsequently the application of digestate-enriched biochar and clinoptilolite as fertiliser. Therefore...... the overall objective of this thesis is to investigate the use of clinoptilolite and biochar to recover plant nutrients from the liquid fraction of digestate resulting from anaerobic digestion of animal manure and investigate the plant-availability of the recovered form of nutrients. In Chapter 1 (General...... of nutrients on sorbent) but decreasing efficiencies of clinoptilolite to remove nutrients from the liquid fraction of digestate. In Chapter 3, I studied the chemical activation of biochar by treating the biochar with deionised water, hydrogen peroxide, sulfuric acid and sodium hydroxide solutions...

  17. Alterações no teores de nutrientes em dois solos alagados, com e sem plantas de arroz Nutrients concentration changes in two flooded soils during the rice cycle

    Directory of Open Access Journals (Sweden)

    Leandro Souza da Silva

    2003-06-01

    Full Text Available O alagamento e a presença de plantas alteram as propriedades biológicas e químicas do solo em relação ao ambiente anteriormente oxidado, influenciando a disponibilidade de nutrientes. Foi conduzido um experimento com o objetivo de avaliar as alterações dos teores de alguns nutrientes na solução de um Planossolo e um Gleissolo durante o ciclo do arroz. Os solos foram acondicionados em vasos (50 litros contendo dispositivos para coleta da solução em diferentes profundidades, mantidos sem ou com plantas de arroz. A solução foi coletada aos 10, 19, 44, 77 e 113 dias de alagamento e determinados os teores de P, K, Ca, Mg, Fe e Mn. A concentração dos nutrientes na solução, especialmente o K, variou com a profundidade de coleta e com a presença de plantas, demonstrando a influência desses fatores na disponibilidade dos nutrientes em solos alagados.Flooding a soil and growing plant on it can change its biological and chemistry properties, in comparison with a non-flooded environment. An experiment was conducted in order to study the nutrients dynamics in the solution of two soils (Planossolo and Gleissolo during the rice cycle. Rice plants were cultivated in 50L containers having devices to collect soil solution at several depths (2.5, 5.0, 7.5 and 31cm. In the soil solution, with and without plant, P, K, Ca, Mg, Fe and Mn, were measured at 10, 19, 44, 77, and 113 days after the flooding. Potassium was especially sensible to the rice plant and depth of sampling

  18. NPK fertilization effects on concentration of nutrients in Valencia orange leaves

    International Nuclear Information System (INIS)

    Basso, C.; Mielniczuk, J.; Bohnen, H.

    1983-01-01

    The effects of NPK fertilization on the nutrient concentration in the leaves was evaluated in a field experiment of Valencia orange (Citrus sinensis Osbeck) growing in a sandy acid soil, with 4N, 3P and 4K fertilizer levels. N and Cu contents in the leaves were high, while P and Zn levels were low, in all treatments. Increasing the levels of N, P 2 O 5 and K 2 O fertilization resulted in an increase of the N, P and K concentration in the leaves, respectively. Crescent levels of N fertilization raised Mn and decreased Ca concentration in the leaves. P and K contents in the leaves correlated positively. With a great availability and absorption of K, reduction on he foliar contents of Mg and Ca ocurred. (M.A.C.) [pt

  19. THE MAIN NUTRIENTS CONCENTRATION FROM INTRA TISSUE WATER OF BENTHOS ORAGANISMS FROM MURES BASIN

    Directory of Open Access Journals (Sweden)

    DANA POPA

    2008-05-01

    Full Text Available In the hydrographic basin of Mures river, aboard an altitude gradient, were taken samples of intra tissue waters from benthonic organisms for research the nutrients concentrations. The reference point was represented by a dairy caw farm where the agricultural fields of this is applied the organic fertilization with manure. The intra tissue water samples from benthonic organisms were prelevated in spring and autumn and the prelevate dates are the same with spread manure dates. At the intra tissue water level, concentrations value of N and P are bigger at the second data prelevations than first data prelevations and we can conclude that the benthonic oligochetas activity increase, more than, they density increase in Mures basin. The high concentrations of NH4 show as that Mures basin is a zone characterized by high degree of anoxia and this fact is supported by significant differences between seasonal prelevations. The explication is the manifestation to the cumulated and at distance effects of introduction in water to some organic products, very probably washed from neighborhoods agricultural field. Were calculated values of Student test for seasonal comparisons and were founded significant differences between nutrients concentration values at first and second prelevations.

  20. USE CELLULOSE FOR CLEANING CONCENTRATED SUGAR SOLUTIONS

    Directory of Open Access Journals (Sweden)

    N. G. Kul’neva

    2015-01-01

    Full Text Available Summary. Producing high quality intermediate products in the boiling-crystallization station is an actual problem of sugar production. In the production of white sugar brown sugar syrup is not further purified that decreases the quality of the end product. Studies have been conducted using cellulose as an adsorbent for the purification of concentrated sugar solutions, having affinity to dyes and other impurities. Research have been carried out with the intermediate products of the Lebedyan sugar plant. Test results have shown cellulose ability to adsorb the dyes in sugar production. The influence of the adsorbent concentration and the mass fraction of solids in the syrup on the decolorization effect has been studied; rational process parameters have been obtained. It has been found that proceeding an additional adsorption purification of brown sugars syrup allows to reduce the solution color, increase the amount and quality of the end product. Adsorbing means, received from production wastes on the basis of organic resources, have many advantages: economical, environmentally friendly for disposal, safe to use, reliable and efficient in use. Conducted research on using cellulose as adsorbent for treatment of concentrated sugar solutions, having an affinity for colouring matter and other impurities. The experiments were carried out on the intermediates Lebedyanskiy sugar factory. The test results showed the ability of cellulose to adsorb coloring matter of sugar production. To evaluate the effect of bleaching depending on the mass fraction of dry substances prepared yellow juice filtration of sugar concentration of 55, 60, 65 % with subsequent adsorption purification of cellulose. The results of the experiment built adsorption isotherm of dyestuffs. The influence of the concentration of the adsorbent and a mass fraction of solids of juice filtration on the efficiency of decolorization obtained by rational parameters of the process. It is

  1. Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams

    Science.gov (United States)

    Ciparis, Serena; Iwanowicz, Luke R.; Voshell, J. Reese

    2012-01-01

    Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO4-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17β-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations > 1 ng/L. Relatively high concentrations of DIN (> 1000 μg/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R2 = 0.56–0.81) and E2Eq (R2 = 0.39–0.75). Relationships between watershed densities of AFOs and PO4-P were weaker, but were also significant (R2 = 0.27–0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO4-P than streams without WWTP discharges, and PO4-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms.

  2. Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams.

    Science.gov (United States)

    Ciparis, Serena; Iwanowicz, Luke R; Voshell, J Reese

    2012-01-01

    Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO(4)-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17β-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations >1 ng/L. Relatively high concentrations of DIN (>1000 μg/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R(2) = 0.56-0.81) and E2Eq (R(2) = 0.39-0.75). Relationships between watershed densities of AFOs and PO(4)-P were weaker, but were also significant (R(2) = 0.27-0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO(4)-P than streams without WWTP discharges, and PO(4)-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Nitrate concentrations in soil solutions below Danish forests

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Raulund-Rasmussen, Karsten; Gundersen, Per

    1999-01-01

    leaching in relation to land-use, a national monitoring programme has established sampling routines in a 7x7 km grid including 111 points in forests. During winters of 1986-1993, soil samples were obtained from a depth of 0-25, 25-50, 50-75 and 75-100 cm. Nitrate concentrations in soil solutions were...... species. A few sites deviated radically from the general pattern of low concentrations. The elevated concentrations recorded there were probably caused by high levels of N deposition due to emission from local sources or temporal disruptions of the N cycle. The nitrate concentration in the soil solution...

  4. New Culture Medium Containing Ionic Concentrations of Nutrients Similar to Concentrations Found in the Soil Solution

    Science.gov (United States)

    Angle, J. Scott; McGrath, Stephen P.; Chaney, Rufus L.

    1991-01-01

    A new growth medium which closely approximates the composition of the soil solution is presented. This soil solution equivalent (SSE) medium contains the following components (millimolar): NO3, 2.5; NH4, 2.5; HPO4, 0.005; Na, 2.5; Ca, 4.0; Mg, 2.0; K, 0.503; Cl, 4.0; SO4, 5.0; ethylenediamine-di(o-hydroxyphenylacetic acid), 0.02; and MES [2-(N-morpholino)ethanesulfonic acid] (to maintain the pH at 6.0), 10, plus 0.1% arabinose. The advantages of the SSE medium are discussed. PMID:16348614

  5. The influence of gadolinium and yttrium on biomass production and nutrient balance of maize plants

    International Nuclear Information System (INIS)

    Saatz, Jessica; Vetterlein, Doris; Mattusch, Jürgen; Otto, Matthias; Daus, Birgit

    2015-01-01

    Rare earth elements (REE) are expected to become pollutants by enriching in the environment due to their wide applications nowadays. The uptake and distribution of gadolinium and yttrium and its influence on biomass production and nutrient balance was investigated in hydroponic solution experiments with maize plants using increasing application doses of 0.1, 1 and 10 mg L −1 . It could be shown that concentrations of up to 1 mg L −1 of Gd and Y did not reduce or enhance the plant growth or alter the nutrient balance. 10 mg L −1  Gd or Y resulted in REE concentrations of up to 1.2 weight-% in the roots and severe phosphate deficiency symptoms. Transfer rates showed that there was only little transport of Gd and Y from roots to shoots. Significant correlations were found between the concentration of Gd and Y in the nutrient solution and the root tissue concentration of Ca, Mg and P. - Highlights: • Roots accumulate REE in very high concentrations. • Transfer factors from root to shoot tissue are very low, with HREE higher than MREE. • The nutrient balance of the plant is severely influenced by REE addition. • Phosphate deficiency appears at high concentrations of REE addition. - The addition of the rare-earth elements Gd and Y results in less Ca and Mg uptake and phosphate deficiency in maize plants grown in hydroponics

  6. The effect of concentration and exposure time on 15N uptake and incorporation from urea and ammonium nitrate by spring barley in the initial growth period

    International Nuclear Information System (INIS)

    Matula, J.; Knop, K.

    1978-01-01

    The uptake and incorporation of 15 N from urea and ammonium nitrate by spring barley were studied in aquaculture at three nitrogen concentrations in complex nutrient solutions (28, 140 and 700 mg N per 1 litre) and for three lengths of exposure to 15 N-labelled nutrient solutions. The 'Diamant' variety plants were precultivated up to the stage of the 3rd to 4th leaf in a complex nutrient solution, and five days prior to exposure to 15 N-labelled solutions the plants were cultivated in a nutrient solution without nitrogen. At a concentration of 28 mg N per litre the course of urea absorption was similar to the absorption of ammonium nitrate, but at a lower level. The results suggest that urea uptake is basically controlled by the metabolic requirement, particularly at lower concentrations. Only at the highest concentrations of nitrogen in the nutrient solutions did the 15 N of urea and ammonium nitrate penetrate into the roots, passive uptake being preferred. The uptake of urea is controlled by the metabolic requirement but its availability for barley metabolism is lower. Ammonium nitrate NO 3 - was taken up at a lower rate than NH 4 + from the same compound. Nitrate nitrogen was transported relatively more intensively to the above-ground parts of barley. The increasing concentration of nitrogen and exposure to nutrient solutions induced a rise in the proportion of ethanol-soluble forms of nitrogen, particularly in the roots. (author)

  7. Biochar and manure affect calcareous soil and corn silage nutrient concentrations and uptake.

    Science.gov (United States)

    Lentz, R D; Ippolito, J A

    2012-01-01

    Carbon-rich biochar derived from the pyrolysis of biomass can sequester atmospheric CO, mitigate climate change, and potentially increase crop productivity. However, research is needed to confirm the suitability and sustainability of biochar application to different soils. To an irrigated calcareous soil, we applied stockpiled dairy manure (42 Mg ha dry wt) and hardwood-derived biochar (22.4 Mg ha), singly and in combination with manure, along with a control, yielding four treatments. Nitrogen fertilizer was applied when needed (based on preseason soil test N and crop requirements) in all plots and years, with N mineralized from added manure included in this determination. Available soil nutrients (NH-N; NO-N; Olsen P; and diethylenetriaminepentaacetic acid-extractable K, Mg, Na, Cu, Mn, Zn, and Fe), total C (TC), total N (TN), total organic C (TOC), and pH were evaluated annually, and silage corn nutrient concentration, yield, and uptake were measured over two growing seasons. Biochar treatment resulted in a 1.5-fold increase in available soil Mn and a 1.4-fold increase in TC and TOC, whereas manure produced a 1.2- to 1.7-fold increase in available nutrients (except Fe), compared with controls. In 2009 biochar increased corn silage B concentration but produced no yield increase; in 2010 biochar decreased corn silage TN (33%), S (7%) concentrations, and yield (36%) relative to controls. Manure produced a 1.3-fold increase in corn silage Cu, Mn, S, Mg, K, and TN concentrations and yield compared with the control in 2010. The combined biochar-manure effects were not synergistic except in the case of available soil Mn. In these calcareous soils, biochar did not alter pH or availability of P and cations, as is typically observed for acidic soils. If the second year results are representative, they suggest that biochar applications to calcareous soils may lead to reduced N availability, requiring additional soil N inputs to maintain yield targets. Copyright © by the

  8. Dredging effects on selected nutrient concentrations and ecoenzymatic activity in two drainage ditch sediments in the lower Mississippi River Valley

    Directory of Open Access Journals (Sweden)

    Matt Moore

    2017-09-01

    Full Text Available Agricultural drainage ditches are conduits between production acreage and receiving aquatic systems. Often overlooked for their mitigation capabilities, agricultural drainage ditches provide an important role for nutrient transformation via microbial metabolism. Variations in ecoenzyme activities have been used to elucidate microbial metabolism and resource demand of microbial communities to better understand the relationship between altered nutrient ratios and microbial activity in aquatic ecosystems. Two agricultural drainage ditches, one in the northeast portion of the Arkansas Delta and the other in the lower Mississippi Delta, were monitored for a year. Sediment samples were collected prior to each ditch being dredged (cleaned, and subsequent post-dredging samples occurred as soon as access was available. Seasonal samples were then collected throughout a year to examine effects of dredging on selected nutrient concentrations and ecoenzymatic activity recovery in drainage ditch sediments. Phosphorus concentrations in sediments after dredging decreased 33–66%, depending on ditch and phosphorus extraction methodology. Additionally, ecoenzymatic activity was significantly decreased in most sediment samples after dredging. Fluorescein diacetate hydrolysis activity, an estimate of total microbial activity, decreased 56–67% after dredging in one of the two ditches. Many sample sites also had significant phosphorus and ecoenzymatic activity differences between the post-dredge samples and the year-long follow-up samples. Results indicate microbial metabolism in dredged drainage ditches may take up to a year or more to recover to pre-dredged levels. Likewise, while sediment nutrient concentrations may be decreased through dredging and removal, runoff and erosion events over time tend to quickly replenish nutrient concentrations in replaced sediments. Understanding nutrient dynamics and microbial metabolism within agricultural drainage ditches is

  9. Closed-Cycle Nutrient Supply For Hydroponics

    Science.gov (United States)

    Schwartzkopf, Steven H.

    1991-01-01

    Hydroponic system controls composition and feed rate of nutrient solution and recovers and recycles excess solution. Uses air pressure on bladders to transfer aqueous nutrient solution. Measures and adjusts composition of solution before it goes to hydroponic chamber. Eventually returns excess solution to one of tanks. Designed to operate in microgravity, also adaptable to hydroponic plant-growing systems on Earth.

  10. A discussion about maximum uranium concentration in digestion solution of U3O8 type uranium ore concentrate

    International Nuclear Information System (INIS)

    Xia Dechang; Liu Chao

    2012-01-01

    On the basis of discussing the influence of single factor on maximum uranium concentration in digestion solution,the influence degree of some factors such as U content, H 2 O content, mass ratio of P and U was compared and analyzed. The results indicate that the relationship between U content and maximum uranium concentration in digestion solution was direct ratio, while the U content increases by 1%, the maximum uranium concentration in digestion solution increases by 4.8%-5.7%. The relationship between H 2 O content and maximum uranium concentration in digestion solution was inverse ratio, the maximum uranium concentration in digestion solution decreases by 46.1-55.2 g/L while H 2 O content increases by 1%. The relationship between mass ratio of P and U and maximum uranium concentration in digestion solution was inverse ratio, the maximum uranium concentration in digestion solution decreases by 116.0-181.0 g/L while the mass ratio of P and U increase 0.1%. When U content equals 62.5% and the influence of mass ratio of P and U is no considered, the maximum uranium concentration in digestion solution equals 1 578 g/L; while mass ratio of P and U equals 0.35%, the maximum uranium concentration decreases to 716 g/L, the decreased rate is 54.6%, so the mass ratio of P and U in U 3 O 8 type uranium ore concentrate is the main controlling factor. (authors)

  11. Fertilizer drawn forward osmosis process for sustainable water reuse to grow hydroponic lettuce using commercial nutrient solution

    KAUST Repository

    Chekli, Laura; Eun Kim, Jung; El Saliby, Ibrahim; Kim, Youngjin; Phuntsho, Sherub; Li, Sheng; Ghaffour, NorEddine; Leiknes, TorOve; Kyong Shon, Ho

    2017-01-01

    This study investigated the sustainable reuse of wastewater using fertilizer drawn forward osmosis (FDFO) process through osmotic dilution of commercial nutrient solution for hydroponics, a widely used technique for growing plants without soil

  12. Characterizing nutrient uptake kinetics for efficient crop production during Solanum lycopersicum var. cerasiforme Alef. growth in a closed indoor hydroponic system.

    Science.gov (United States)

    Lee, Ju Yeon; Rahman, Arifur; Azam, Hossain; Kim, Hyung Seok; Kwon, Man Jae

    2017-01-01

    A balanced nutrient supply is essential for the healthy growth of plants in hydroponic systems. However, the commonly used electrical conductivity (EC)-based nutrient control for plant cultivation can provide amounts of nutrients that are excessive or inadequate for proper plant growth. In this study, we investigated the kinetics of major and minor nutrient uptake in a nutrient solution during the growth of tomato (Solanum lycopersicum var. cerasiforme Alef.) in a closed hydroponic system. The concentrations of major and minor ions in the nutrient solution were determined by various analytical methods including inductively coupled plasma-optical emission spectroscopy (ICP-OES), ion chromatography (IC), ion specific electrodes, and/or colorimetric methods. The concentrations of the individual nutrient ions were compared with changes in the EC. The EC of the nutrient solution varied according to the different growth stages of tomato plants. Variation in the concentrations of NO3-, SO42-, Mg2+, Ca2+, and K+ was similar to the EC variation. However, in the cases of PO43-, Na+, Cl-, dissolved Fe and Mn, Cu2+, and Zn2+, variation did not correspond with that of EC. These ions were generally depleted (to 0 mg L-1) during tomato growth, suggesting that these specific ions should be monitored individually and their supply increased. Nutrient uptake rates of major ions increased gradually at different growth stages until harvest (from 15 mg L-1 d-1). Saturation indices determined by MINEQL+ simulation and a mineral precipitation experiment demonstrated the potential for amorphous calcium phosphate precipitation, which may facilitate the abiotic adsorptive removal of dissolved Fe, dissolved Mn, Cu2+, and Zn2+.

  13. Impact of solute concentration on the electrocatalytic conversion of dissolved gases in buffered solutions

    KAUST Repository

    Shinagawa, Tatsuya

    2015-04-24

    To maintain local pH levels near the electrode during electrochemical reactions, the use of buffer solutions is effective. Nevertheless, the critical effects of the buffer concentration on electrocatalytic performances have not been discussed in detail. In this study, two fundamental electrochemical reactions, oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR), on a platinum rotating disk electrode are chosen as model gas-related aqueous electrochemical reactions at various phosphate concentrations. Our detailed investigations revealed that the kinetic and limiting diffusion current densities for both the ORR and HOR logarithmically decrease with increasing solute concentration (log|jORR|=-0.39c+0.92,log|jHOR|=-0.35c+0.73). To clarify the physical aspects of this phenomenon, the electrolyte characteristics are addressed: with increasing phosphate concentration, the gas solubility decrease, the kinematic viscosity of the solution increase and the diffusion coefficient of the dissolved gases decrease. The simulated limiting diffusion currents using the aforementioned parameters match the measured ones very well (log|jORR|=-0.43c+0.99,log|jHOR|=-0.40c+0.54), accurately describing the consequences of the electrolyte concentration. These alterations of the electrolyte properties associated with the solute concentration are universally applicable to other aqueous gas-related electrochemical reactions because the currents are purely determined by mass transfer of the dissolved gases. © 2015 The Authors.

  14. Biofortification of lettuce (Lactuca sativa L.) with iodine: the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce grown in water culture.

    Science.gov (United States)

    Voogt, Wim; Holwerda, Harmen T; Khodabaks, Rashied

    2010-04-15

    Iodine is an essential trace element for humans. Two billion individuals have insufficient iodine intake. Biofortification of vegetables with iodine offers an excellent opportunity to increase iodine intake by humans. The main aim was to study the effect of iodine form and concentration in the nutrient solution on growth, development and iodine uptake of lettuce, grown in water culture. In both a winter and summer trial, dose rates of 0, 13, 39, 65, and 90 or 129 microg iodine L(-1), applied as iodate (IO(3)(-)) or iodide (I(-)), did not affect plant biomass, produce quality or water uptake. Increases in iodine concentration significantly enhanced iodine content in the plant. Iodine contents in plant tissue were up to five times higher with I(-) than with IO(3)(-). Iodine was mainly distributed to the outer leaves. The highest iodide dose rates in both trials resulted in 653 and 764 microg iodine kg(-1) total leaf fresh weight. Biofortification of lettuce with iodine is easily applicable in a hydroponic growing system, both with I(-) and IO(3)(-). I(-) was more effective than IO(3)(-). Fifty grams of iodine-biofortified lettuce would provide, respectively, 22% and 25% of the recommended daily allowance of iodine for adolescents and adults. (c) 2010 Society of Chemical Industry.

  15. Nutrient concentrations in leachate and runoff from dairy cattle lots with different surface materials

    Science.gov (United States)

    Nitrogen (N) and phosphorus (P) loss from agriculture persists as a water quality issue, and outdoor cattle lots can have a high loss potential. We monitored hydrology and nutrient concentrations in leachate and runoff from dairy heifer lots constructed with three surface materials (soil, sand, bark...

  16. Influence of starch origin on rheological properties of concentrated aqueous solutions

    Directory of Open Access Journals (Sweden)

    Stojanović Željko P.

    2011-01-01

    Full Text Available The rheological properties of corn and potato starch concentrated aqueous solutions were investigated at 25ºC. The starches were previously dispersed in water and the solutions were obtained by heating of dispersions at 115-120ºC for 20 minutes. The solutions of potato starch were transparent, while the corn starch solutions were opalescent. The results of dynamic mechanical measurements showed that the values of viscosity, h, storage modulus, G′, and loss modulus, G″, of the corn starch solutions increased with the storage time. This phenomenon was not observed for the potato starch solutions. It was assumed that the increase of h, G′ and G″ is the result of starch solutions retrogradation. The potato starch solutions retrogradation did not occur probably because of the phosphates presence. The viscosity of 2 mass % corn starch solution is less than the viscosity of 2 mass % potato starch solution. By increasing the concentration of corn starch solution the gel with elastic behavior was formed. The corn starch solutions formed gel as early as at 4 mass % concentration, while potato starch solutions achieved the gel state at the concentration of 5 mass %. The value of exponent m (G′ and G″ µ wm during the transition of potato starch solutions to gel is 0.414, which gives the fractal dimensions for corn starch of 2.10. The obtained value of fractal dimension corresponds to slow aggregation. The corn starch solutions with the starch concentrations higher than 4 mass % form weak gels. For these solutions the values of modulus in rubber plateau were determined. It was found that the modulus in rubber plateau increased with the concentration by the exponent of 4.36. Such high exponent value was obtained in the case when the tridimensional network is formed, i.e. when supermolecular structures like associates or crystal domains are formed.

  17. Numerical simulations of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay, Indonesia

    International Nuclear Information System (INIS)

    Wulp, Simon A. van der; Damar, Ario; Ladwig, Norbert; Hesse, Karl-J.

    2016-01-01

    The present application of numerical modelling techniques provides an overview of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay. A hydrological model simulated river discharges with a total of 90 to 377 m 3 s −1 entering Jakarta Bay. Daily total nitrogen and total phosphorus loads ranged from 40 to 174 tons and 14 to 60 tons, respectively. Flow model results indicate that nutrient gradients are subject to turbulent mixing by tides and advective transport through circulation driven by wind, barotropic and baroclinic pressure gradients. The bulk of nutrient loads originate from the Citarum and Cisadane rivers flowing through predominantly rural areas. Despite lower nutrient loads, river discharges from the urban area of Jakarta exhibit the highest impact of nutrient concentrations in the near shore area of Jakarta Bay and show that nutrient concentrations were not only regulated by nutrient loads but were strongly regulated by initial river concentrations and local flow characteristics. - Highlights: • Full overview of river discharges, nutrient flux and nutrient levels in Jakarta Bay • Important overview of nutrient flux from individual rivers • Simulations identify the principal drivers of water circulation and nutrient gradient. • Nutrient dispersion model includes the local effects of the Java Sea current system.

  18. Numerical simulations of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay, Indonesia.

    Science.gov (United States)

    van der Wulp, Simon A; Damar, Ario; Ladwig, Norbert; Hesse, Karl-J

    2016-09-30

    The present application of numerical modelling techniques provides an overview of river discharges, nutrient flux and nutrient dispersal in Jakarta Bay. A hydrological model simulated river discharges with a total of 90 to 377m(3)s(-1) entering Jakarta Bay. Daily total nitrogen and total phosphorus loads ranged from 40 to 174tons and 14 to 60tons, respectively. Flow model results indicate that nutrient gradients are subject to turbulent mixing by tides and advective transport through circulation driven by wind, barotropic and baroclinic pressure gradients. The bulk of nutrient loads originate from the Citarum and Cisadane rivers flowing through predominantly rural areas. Despite lower nutrient loads, river discharges from the urban area of Jakarta exhibit the highest impact of nutrient concentrations in the near shore area of Jakarta Bay and show that nutrient concentrations were not only regulated by nutrient loads but were strongly regulated by initial river concentrations and local flow characteristics. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Osmotic potential calculations of inorganic and organic aqueous solutions over wide solute concentration levels and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Cochrane, T. T., E-mail: agteca@hotmail.com [AGTECA S.A., 230 Oceanbeach Road, Mount Maunganui, Tauranga 3116 (New Zealand); Cochrane, T. A., E-mail: tom.cochrane@canterbury.ac.nz [Department of Civil and Natural Resources Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand)

    2016-01-15

    Purpose: To demonstrate that the authors’ new “aqueous solution vs pure water” equation to calculate osmotic potential may be used to calculate the osmotic potentials of inorganic and organic aqueous solutions over wide ranges of solute concentrations and temperatures. Currently, the osmotic potentials of solutions used for medical purposes are calculated from equations based on the thermodynamics of the gas laws which are only accurate at low temperature and solute concentration levels. Some solutions used in medicine may need their osmotic potentials calculated more accurately to take into account solute concentrations and temperatures. Methods: The authors experimented with their new equation for calculating the osmotic potentials of inorganic and organic aqueous solutions up to and beyond body temperatures by adjusting three of its factors; (a) the volume property of pure water, (b) the number of “free” water molecules per unit volume of solution, “N{sub f},” and (c) the “t” factor expressing the cooperative structural relaxation time of pure water at given temperatures. Adequate information on the volume property of pure water at different temperatures is available in the literature. However, as little information on the relative densities of inorganic and organic solutions, respectively, at varying temperatures needed to calculate N{sub f} was available, provisional equations were formulated to approximate values. Those values together with tentative t values for different temperatures chosen from values calculated by different workers were substituted into the authors’ equation to demonstrate how osmotic potentials could be estimated over temperatures up to and beyond bodily temperatures. Results: The provisional equations formulated to calculate N{sub f}, the number of free water molecules per unit volume of inorganic and organic solute solutions, respectively, over wide concentration ranges compared well with the calculations of N{sub f

  20. Osmotic potential calculations of inorganic and organic aqueous solutions over wide solute concentration levels and temperatures

    International Nuclear Information System (INIS)

    Cochrane, T. T.; Cochrane, T. A.

    2016-01-01

    Purpose: To demonstrate that the authors’ new “aqueous solution vs pure water” equation to calculate osmotic potential may be used to calculate the osmotic potentials of inorganic and organic aqueous solutions over wide ranges of solute concentrations and temperatures. Currently, the osmotic potentials of solutions used for medical purposes are calculated from equations based on the thermodynamics of the gas laws which are only accurate at low temperature and solute concentration levels. Some solutions used in medicine may need their osmotic potentials calculated more accurately to take into account solute concentrations and temperatures. Methods: The authors experimented with their new equation for calculating the osmotic potentials of inorganic and organic aqueous solutions up to and beyond body temperatures by adjusting three of its factors; (a) the volume property of pure water, (b) the number of “free” water molecules per unit volume of solution, “N f ,” and (c) the “t” factor expressing the cooperative structural relaxation time of pure water at given temperatures. Adequate information on the volume property of pure water at different temperatures is available in the literature. However, as little information on the relative densities of inorganic and organic solutions, respectively, at varying temperatures needed to calculate N f was available, provisional equations were formulated to approximate values. Those values together with tentative t values for different temperatures chosen from values calculated by different workers were substituted into the authors’ equation to demonstrate how osmotic potentials could be estimated over temperatures up to and beyond bodily temperatures. Results: The provisional equations formulated to calculate N f , the number of free water molecules per unit volume of inorganic and organic solute solutions, respectively, over wide concentration ranges compared well with the calculations of N f using recorded

  1. Effect of nitrogen form and pH of nutrient solution on the changes in pH and EC of spinach rhizosphere in hydroponic culture

    OpenAIRE

    M. Parsazadeh; N. Najafi

    2011-01-01

    In this study, the effect of nitrate to ammonium ratio and pH of nutrient solution on the changes in pH and EC of rhizosphere during spinach growth period in perlite culture, under greenhouse conditions, was investigated. A split factorial experiment in a completely randomized design with four replications was conducted with three factors including nutrient solution’s pH in three levels (4.5, 6.5 and 8), nitrate to ammonium ratio of nutrient solution in five levels (100:0, 75:25, 50:50, 25:75...

  2. Effect of thymol and carvacrol on nutrient digestibility in rams fed high or low concentrate diets.

    Science.gov (United States)

    Zamiri, M J; Azizabadi, E; Momeni, Z; Rezvani, M R; Atashi, H; Akhlaghi, A

    2015-01-01

    Published data on the effects of essential oils (EO) on in vivo nutrient digestibility in sheep are contradictory. In 2 experiments, the effect of thymol and carvacrol on nutrient digestibility was studied in sheep fed with high (70%) or low (52%) concentrate diets, using incomplete Latin Square designs. The essential oils were mixed with the concentrate portion of the diet at the rate of 0.0, 0.3, or 0.6 g per kg dry matter (DM) diet. Supplementation of thymol had no significant effect on digestibility of dry matter (DM), organic matter (OM), crude protein (CP) and acid detergent fiber (ADF). The main effect of thymol on neutral detergent fiber (NDF) and ether extract (EE) digestibility and on nitrogen balance (NB) was significant (Pdigestibility. The main effect of carvacrol on ruminal ammonia levels and NB was significant, but within each level of dietary concentrate no significant differences were observed in ammonia levels and NB. Inclusion of 0.3 g/kg diet DM of carvacrol or thyme was more effective than 0.6 g/kg diet DM in terms of NB but neither dose affected nutrient digestibility. Future research should determine the long-term effects of essential oils on digestibility and performance in sheep, before recommendation can be made for their use under practical husbandry conditions.

  3. Evanescent Wave Absorption Based Fiber Sensor for Measuring Glucose Solution Concentration

    Science.gov (United States)

    Marzuki, Ahmad; Candra Pratiwi, Arni; Suryanti, Venty

    2018-03-01

    An optical fiber sensor based on evanescent wave absorption designed for measuring glucose solution consentration was proposed. The sensor was made to detect absorbance of various wavelength in the glucose solution. The sensing element was fabricated by side polishing of multimode polymer optical fiber to form a D-shape. The sensing element was immersed in different concentration of glucoce solution. As light propagated through the optical fiber, the evanescent wave interacted with the glucose solution. Light was absorbed by the glucose solution. The larger concentration the glucose solution has, the more the evanescent wave was absorbed in particular wavelenght. Here in this paper, light absorbtion as function of glucose concentration was measured as function of wavelength (the color of LED). We have shown that the proposed sensor can demonstrated an increase of light absorption as function of glucose concentration.

  4. Long-Term Trends in Nutrient Concentrations and Fluxes in Streams Draining to Lake Tahoe, California

    Science.gov (United States)

    Domagalski, J. L.

    2017-12-01

    Lake Tahoe, situated in the rain shadow of the eastern Sierra Nevada at an elevation of 1,897 meters, has numerous small to medium sized tributaries that are sources of nutrients and fine sediment. The Tahoe watershed is relatively small and the surface area of the lake occupies about 38% of the total watershed area (1,313 km2). Each stream contributing water to the lake therefore also occupies a small watershed, mostly forested, with typical trees being Jeffrey, Ponderosa, or Sugar Pine and White Fir. Outflow from the lake contributes to downstream uses such as water supply and ecological resources. Only about 6% of the watershed is urbanized or residential land, and wastewater is exported to adjacent basins and not discharged to the lake as part of a plan to maintain water clarity. The lake's exceptional clarity has been diminishing due to phytoplankton and fine sediment, prompting development of management plans to improve water quality. Much of the annual discharge and flux of nutrients to the lake results from snowmelt in the spring and summer months, and climatic changes have begun to shift this melt to earlier time frames. Winter rains on urbanized land also contribute to nutrient loads. To understand the relative importance of land use, climate, and other factors affecting stream concentrations and fluxes, a Weighted Regression on Time Discharge and Season (WRTDS) model documented trends over a time frame of greater than 25 years. Ten streams have records of discharge, nutrient (NO3, NH3, OP, TP, TKN) and sediment data to complete this analysis. Both urbanized and non-urbanized locations generally show NO3 trending down in the 1980s. Some locations show initially decreasing orthophosphate trends, followed by small significant increases in concentration and fluxes starting around 2000 to 2005. Although no wastewater enters the streams, ammonia concentrations mimic those of orthophosphate, with initially negative trends in concentration and flux followed by

  5. Concentração de nitrogênio na solução nutritiva, na produtividade e na qualidade de frutos de melão cultivado em substrato Nitrogen concentration of the nutrient solution on yield and quality of muskmelon fruits grown in substrate

    Directory of Open Access Journals (Sweden)

    Marco Aurélio de Freitas Fogaça

    2007-02-01

    Full Text Available Este experimento foi conduzido em ambiente protegido, na UFSM, entre agosto de 2004 e janeiro de 2005, com o híbrido "Magelan". As mudas foram plantadas em sacolas de polietileno contendo 4,5dm3 do substrato Plantmax PXT®, na densidade de 3,3 plantas m-2. As plantas foram conduzidas verticalmente em haste única, com até dois frutos por planta, e despontadas ao atingir a altura de 2m. Os tratamentos foram constituídos por concentrações de nitrogênio na solução nutritiva de 8 (T1, 11 (T2, 14 (T3, 17 (T4 e 20 (T5 mmol L-1. Os demais nutrientes foram fornecidos nas concentrações, em mmol L-1, de 0,9 de H2PO4-; 2,25 de SO4--; 10,0 de Ca++; 6,0 de K+ e 5,0 de Mg++, e, em mg L-1, 0,42 de Mn; 0,26 de Zn; 0,05 de Cu; 0,50 de B; 0,04 de Mo e 4,82 de quelato de Fe. A solução nutritiva foi fornecida várias vezes ao dia, de acordo com a demanda hídrica da cultura, com um coeficiente de drenagem diário não inferior a 30%. O delineamento experimental foi inteiramente casualizado, com cinco tratamentos e quatro repetições. Foi observada resposta linear dos tratamentos na matéria seca vegetativa e de frutos, na área foliar, no número de frutos e na produtividade. Quanto às características qualitativas dos frutos, somente a acidez titulável apresentou diferença significativa, decrescendo com o aumento da concentração de N. A concentração de até 20mmol L-1 de N pode ser empregada na fertirrigação de lavouras comerciais dessa cultura em substrato.The experiment was carried out inside a greenhouse at UFSM, from August to January 2005, using the hybrid Magelan. Planting was made in polyethylene bags with 4.5dm3 of the commercial substrate Plantmax PXT®, in a plant density of 3.3 plants m-2. Plants were vertically trained with two fruits per plant and the main stem was cut at 2m height. Treatments were N concentrations of 8 (T1, 11 (T2, 14 (T3, 17 (T4 and 20 (T5 mmol L-1 in the nutrient solution. The other nutrients were supplied at

  6. Automated assay of uranium solution concentration and enrichment

    International Nuclear Information System (INIS)

    Horley, E.C.; Gainer, K.; Hansen, W.J.; Kelley, T.A.; Parker, J.L.; Sampson, T.E.; Walton, G.; Jones, S.A.

    1992-01-01

    For the first time, the concentration and enrichment of uranium solutions can be measured in one step. We have developed a new instrument to automatically measure the concentration and enrichment of uranium solutions through the adaptation of a commercial robot. Two identical solution enrichment systems are being installed in the Portsmouth Gaseous Diffusion Plant. These automated systems will reduce radiation exposure to personnel and increase the reliability and repeatability of the measurements. Each robotic system can process up to 40 batch and 8 priority samples in an unattended mode. Both passive gamma-ray and x-ray fluorescence (XRF) analyses are performed to determine total uranium concentration and 235 U enrichment. Coded samples are read by a bar-code reader to determine measurement requirements, then assayed by either or both of the gamma-ray and XRF instruments. The robot moves the sample containers and operates all shield doors and shutters, reducing hardware complexity. If the robots is out of service, an operator can manually perform all operations

  7. Geographic variation in the relationships of temperature, salinity or sigma sub t versus plant nutrient concentrations in the world ocean. [silicic acid, nitrate, and phosphate concentration

    Science.gov (United States)

    Kamykowski, D.; Zentara, S. J.

    1985-01-01

    A NODC data set representing all regions of the world ocean was analyzed for temperature and sigma-t relationships with nitrate, phosphate or silicic acid. Six cubic regressions were for each ten degree square of latitude and longitude containing adequate data. World maps display the locations that allow the prediction of plant nutrient concentrations from temperature or sigma-t. Geographic coverage improves along the sequence: nitrate, phosphate, and silicic acid and is better for sigma-t than for temperature. Contour maps of the approximate temperature of sigma-t at which these nitrients are no longer measurable in a parcel of water are generated, based on a percentile analysis of the temperature or sigma-t at which less than a selected amount of plant nutrient occurs. Results are stored on magnetic tape in tabular form. The global potential to predict plant nutrient concentrations from remotely sensed temperature of sigma-t and to emphasize the latitudinally and longitudinally changing phytoplankton growth environment in present and past oceans is demonstrated.

  8. Nutrient digestibility and beef cattle performance fed by lerak (Sapindus rarak meal in concentrate ration

    Directory of Open Access Journals (Sweden)

    S. Suharti

    2009-10-01

    Full Text Available This research was aimed to study the use of Lerak fruit meal to improve performance and feed digestibility of beef cattle. The research consisted of two trials (in vitro and in vivo studies. The in vitro trial was screening of bioactive compounds (saponin, tanin, dan diosgenin in Lerak fruit (including seed and continued to evaluate the effectivity of these compounds against ruminal protozoa. The in vivo study was done using 12 Ongole Crossbreed cattle which received 1of 3 different treatments: 1 concentrate without Lerak as control, 2 concentrate containing 2.5% Lerak, and 3 concentrate containing 5% Lerak. Anti protozoal activity, daily gain, and nutrient digestibility of beef cattle were measured. Results showed that saponin concentration in Lerak extracted by methanol was higher than that in Lerak extracted by water and Lerak meal, 81.5%; 8.2% and 3.85% respectively. Lerak extracted by methanol have higher antiprotozoal activity in vitro than Lerak extracted by water. In vivo experiment showed that there were no significant differences (P>0.05 of nutrient intake and digestibility in all treatments, that means the ration had good palatability and quality. Average daily gain of PO fed 2.5% Lerak was 20% higher than that of control diet (0.9 kg/day.

  9. Influence of concentration on the radiolytic decomposition of thiamine, riboflavin, and pyridoxine in aqueous solution

    Directory of Open Access Journals (Sweden)

    Guadalupe Albarrán

    2014-10-01

    Full Text Available Vitamin loss during irradiation has been claimed as a critical area in food irradiation technology, especially that of thiamine (B1, which has been considered as the most sensitive to radiation. Although it has been suggested that no vitamin deficiency could result from consuming irradiated food, a long debate on the loss of vitamins and other nutrients during food irradiation has been maintained by the lack of experimental studies monitoring decomposition rates at different concentrations and doses. Since thiamine, riboflavin, and pyridoxine are labile vitamins, this study has focused on their radiolytic decomposition in dilute aqueous solutions in the presence of air. The decomposition process was followed by HPLC and UV-spectroscopy. The results obtained in aqueous solutions showed a dependence of the decomposition as a nonlinear function of the dose. Of these three compounds, the decomposition was higher for thiamine than for riboflavin and even less in pyridoxine.

  10. The MANAGE database: nutrient load and site characteristic updates and runoff concentration data.

    Science.gov (United States)

    Harmel, Daren; Qian, Song; Reckhow, Ken; Casebolt, Pamela

    2008-01-01

    The "Measured Annual Nutrient loads from AGricultural Environments" (MANAGE) database was developed to be a readily accessible, easily queried database of site characteristic and field-scale nutrient export data. The original version of MANAGE, which drew heavily from an early 1980s compilation of nutrient export data, created an electronic database with nutrient load data and corresponding site characteristics from 40 studies on agricultural (cultivated and pasture/range) land uses. In the current update, N and P load data from 15 additional studies of agricultural runoff were included along with N and P concentration data for all 55 studies. The database now contains 1677 watershed years of data for various agricultural land uses (703 for pasture/rangeland; 333 for corn; 291 for various crop rotations; 177 for wheat/oats; and 4-33 yr for barley, citrus, vegetables, sorghum, soybeans, cotton, fallow, and peanuts). Across all land uses, annual runoff loads averaged 14.2 kg ha(-1) for total N and 2.2 kg ha(-1) for total P. On average, these losses represented 10 to 25% of applied fertilizer N and 4 to 9% of applied fertilizer P. Although such statistics produce interesting generalities across a wide range of land use, management, and climatic conditions, regional crop-specific analyses should be conducted to guide regulatory and programmatic decisions. With this update, MANAGE contains data from a vast majority of published peer-reviewed N and P export studies on homogeneous agricultural land uses in the USA under natural rainfall-runoff conditions and thus provides necessary data for modeling and decision-making related to agricultural runoff. The current version can be downloaded at http://www.ars.usda.gov/spa/manage-nutrient.

  11. Plutonium solution in concentration range from 8 to 17 G/liter

    Energy Technology Data Exchange (ETDEWEB)

    Rothe, R.E.

    1997-06-01

    This paper very briefly discusses the need for a fundamental criticality study of low concentrations of plutonium solutions. Examples of the occurrence of such solutions, which are characteristic of waste, are cited. Due to the prevalence of decontaminating and decommissioning activities, low concentration solutions are expected to become an important concern. Technical deficiencies in previous calculations are also discussed as a reason for performing low concentration criticality studies. 3 refs.

  12. Plutonium solution in concentration range from 8 to 17 G/liter

    International Nuclear Information System (INIS)

    Rothe, R.E.

    1997-01-01

    This paper very briefly discusses the need for a fundamental criticality study of low concentrations of plutonium solutions. Examples of the occurrence of such solutions, which are characteristic of waste, are cited. Due to the prevalence of decontaminating and decommissioning activities, low concentration solutions are expected to become an important concern. Technical deficiencies in previous calculations are also discussed as a reason for performing low concentration criticality studies. 3 refs

  13. Impact of the river Liffey discharge on nutrient and chlorophyll concentrations in the Liffey estuary and Dublin Bay (Irish Sea)

    Science.gov (United States)

    O'Higgins, T. G.; Wilson, J. G.

    2005-08-01

    Temperature, salinity, nutrients (total oxidised nitrogen (TON), ammonium (NH 4) and orthophosphate (PO 4)) and chlorophyll a were monitored in the Liffey estuary and Dublin Bay from June 2000 to June 2003. Four groups of sites were defined comprising the upper estuary (Gp. I), the outer estuary (Gp. III) with a small set (Gp. II) of sites between Groups I and III heavily influenced by the sewage treatment works outflow, and the Bay proper (Gp. IV). Riverine inputs of TON and PO 4 were calculated at an average of 826 t N y -1 and 31 t P y -1, respectively, and were largely controlled by flow rate. The sewage treatment works were identified as a major source of PO 4 and NH 4 to the system. Mixing in the upper estuary of nutrient limited saline waters with hypernutrified river water regularly (i.e. annually) produced relatively high concentrations of chlorophyll a (>10 mg chl a m -3), and also sporadic blooms with extremely high chlorophyll a values (max. 121.6 mg chl a m -3). These latter phytoplankton blooms occurred in high salinity waters and were due to mixing of nutrient limited saline waters and nutrient rich river waters. The mean annual flux of phytoplankton carbon from the river Liffey was calculated at 23.5 t C y -1, of which half was accumulated or remineralised in the estuary and did not enter the Bay. In the Bay proper (Gp. IV) summer nutrient concentrations dropped below detection limits, and chlorophyll a concentrations followed the classic pattern with a spring bloom maximum of 5.5 mg chl a m -3. This pattern in nutrients and chlorophyll a came from the advection of waters into the Bay from an offshore source. Overall while there was considerable evidence for eutrophication in the estuary, the bay itself showed little biological response to nutrient loading.

  14. Radiolysis of concentrated nitric acid solutions

    International Nuclear Information System (INIS)

    Nagaishi, R.; Jiang, P.Y.; Katsumura, Y.; Domae, M.; Ishigure, K.

    1995-01-01

    A study on electron pulse- and 60 Co γ-radiolysis of concentrated nitric acid and nitrate solutions has been carried out to elucidate the radiation induced reactions taking place in the solutions. Dissociation into NO 2 - and O( 3 P) was proposed as a direct action of the radiation on nitrate and gave the G-values were dependent on the chemical forms of nitrate: g s2 (-NO 3 - )=1.6 and g s2 (-HNO 3 )=2.2 (molecules/100eV). Based on the experimental yields of HNO 2 and reduced Ce IV , the primary yields of radiolysis products of water, g w , were evaluated to clarify the effects of nitrate on spur reactions of water in various nitrate solutions. (author)

  15. Absorption and nutrient concentration in apple (Pyrus mains L.)

    OpenAIRE

    Trani, P.E.; Haag, H.P.; Sarruge, J.R.; Dechen, A.R.; Catani, CB

    1981-01-01

    In order to obtain the following informations: a) dry matter production and extraction of nutrients by the fruits at different ages; b) dry matter production and extraction of nutrient by the leaves and "trunk + branches" collected at the flowering stage; c) dry matter production and export of nutrients by pruning (leaves and branches) at the begining dormant stage; A trial was conducted on Latossolo Vermelho Escuro Orto group (Orthox) at Buri, São Paulo State, Brazil. The material was collec...

  16. Quantifying Nutrient and Mercury Concentrations and Loads in Lake Tahoe Snowpack

    Science.gov (United States)

    Pearson, C.; Obrist, D.; Schumer, R.

    2012-12-01

    Recent climate models predict a large decrease in Sierra Nevada snowpack over the next fifty years as a result of climate change. This decrease will not only affect the hydrologic balance but also change inputs of nutrients and pollutants through atmospheric deposition. In the Lake Tahoe basin, winter precipitation dominates and snowfall provides approximately 70 percent of the annual water input. From the first snowfall until the end of melting, snowpack acts as a temporary storage for atmospheric deposition that accumulates throughout winter and spring. Through melt and runoff processes, these nutrients and pollutants can enter the aquatic ecosystem where they can have detrimental effects on lake clarity and health. Most previous studies in this basin have focused on direct atmospheric deposition loads to the lake surface, and little temporal and spatial information is available on the dynamics of atmospheric deposition in the basin's snowpack. We here present nitrogen (N), phosphorus (P), and mercury (Hg) concentrations and pool sizes in snowpack along two elevational transects in the Tahoe Basin from January to April of 2012. Total N and P concentrations in the snowpack ranged from 0.07 mg/L to 0.38 mg/L and 0.003 mg/L to 0.109 mg/L, respectively. P concentrations showed strong increases from the west-side to the east-side of the basin which we attribute to local (e.g., urban or road-dust), in-basin sources that are distributed along the dominant west-wind patterns. N species, on the other hand, generally showed little spatial trends, indicating that its sources were more diffuse and possibly from out-of- basin. Hg concentrations ranged from 0.81 ppt to 6.25 ppt and showed similar spatial patterns as N. Hg, however, also showed significant snowpack concentration decreases during storm-free periods which we attribute to gaseous losses of Hg back to the atmosphere from photochemical reduction. These emissions are further supported by lower Hg concentrations in

  17. Yield, Quality, and Nutrient Concentrations of Strawberry (Fragaria ×ananassa Duch. cv. 'Sonata') Grown with Different Organic Fertilizer Strategies.

    Science.gov (United States)

    Pokhrel, Bhaniswor; Laursen, Kristian Holst; Petersen, Karen Koefoed

    2015-06-17

    Four combinations of two solid organic fertilizers (Monterra Malt and chicken manure) applied before planting and two liquid organic fertilizers (broad bean and Pioner Hi-Fruit/K-Max) given through drip irrigation (fertigation) were compared with inorganic fertilization regarding growth, yield, nutrient concentration, and fruit quality of strawberries. Broad bean fertigation combined with Monterra Malt resulted in a similar fruit yield as inorganic fertilizer and a higher yield than Monterra Malt combined with Pioner; however, total soluble solids, firmness, and titratable acid were improved with Pioner fertigation, although these parameters were more affected by harvest time than the applied fertilizers. The concentrations of most nutrients in fruits and leaves were higher in inorganically fertigated plants. The reductions in fruit yield in three of four treatments and fruit weight in all organic treatments may be due to a combination of the following conditions in the root zone: (1) high pH and high NH4(+)/NO3(-) ratio; (2) high EC and/or high NaCl concentration; (3) cation imbalance; and (4) nutrient deficiency.

  18. A Wavefront Division Polarimeter for the Measurements of Solute Concentrations in Solutions

    Directory of Open Access Journals (Sweden)

    Sergio Calixto

    2017-12-01

    Full Text Available Polarimeters are useful instruments that measure concentrations of optically active substances in a given solution. The conventional polarimetric principle consists of measuring the rotation angle of linearly polarized light. Here, we present a novel polarimeter based on the study of interference patterns. A Mach–Zehnder interferometer with linearly polarized light at the input is used. One beam passes through the liquid sample and the other is a reference beam. As the linearly polarized sample beam propagates through the optically active solution the vibration plane of the electric field will rotate. As a result, the visibility of the interference pattern at the interferometer output will decrease. Fringe contrast will be maximum when both beams present a polarization perpendicular to the plane of incidence. However, minimum visibility is obtained when, after propagation through the sample the polarization of the sample beam is oriented parallel to the plane of incidence. By using different solute concentrations, a calibration plot is obtained showing the behavior of visibility.

  19. The Effects of Different Isocaloric Oral Nutrient Solutions on Psychophysical, Metabolic, Cognitive, and Olfactory Function in Young Male Subjects

    OpenAIRE

    Bachlechner, Stephan; Denzer-Lippmann, Melanie Y.; Wielopolski, Jan; Fischer, Marie; Buettner, Andrea; Doerfler, Arndt; Schöfl, Christof; Münch, Gerald; Kornhuber, Johannes; Thürauf, Norbert

    2017-01-01

    Food intake influences human cognition, olfaction, hunger, and food craving. However, little research has been done in this field to elucidate the effects of different nutrients. Thus, the goal of our study was to investigate the effects of oral ingestion of different nutrient solutions on olfactory, cognitive, metabolic and psychophysical function. Twenty healthy men participated in our study employing a double-blind, cross-over, repeated measurement design. Participants were tested on four ...

  20. Repeat synoptic sampling reveals drivers of change in carbon and nutrient chemistry of Arctic catchments

    Science.gov (United States)

    Zarnetske, J. P.; Abbott, B. W.; Bowden, W. B.; Iannucci, F.; Griffin, N.; Parker, S.; Pinay, G.; Aanderud, Z.

    2017-12-01

    Dissolved organic carbon (DOC), nutrients, and other solute concentrations are increasing in rivers across the Arctic. Two hypotheses have been proposed to explain these trends: 1. distributed, top-down permafrost degradation, and 2. discrete, point-source delivery of DOC and nutrients from permafrost collapse features (thermokarst). While long-term monitoring at a single station cannot discriminate between these mechanisms, synoptic sampling of multiple points in the stream network could reveal the spatial structure of solute sources. In this context, we sampled carbon and nutrient chemistry three times over two years in 119 subcatchments of three distinct Arctic catchments (North Slope, Alaska). Subcatchments ranged from 0.1 to 80 km2, and included three distinct types of Arctic landscapes - mountainous, tundra, and glacial-lake catchments. We quantified the stability of spatial patterns in synoptic water chemistry and analyzed high-frequency time series from the catchment outlets across the thaw season to identify source areas for DOC, nutrients, and major ions. We found that variance in solute concentrations between subcatchments collapsed at spatial scales between 1 to 20 km2, indicating a continuum of diffuse- and point-source dynamics, depending on solute and catchment characteristics (e.g. reactivity, topography, vegetation, surficial geology). Spatially-distributed mass balance revealed conservative transport of DOC and nitrogen, and indicates there may be strong in-stream retention of phosphorus, providing a network-scale confirmation of previous reach-scale studies in these Arctic catchments. Overall, we present new approaches to analyzing synoptic data for change detection and quantification of ecohydrological mechanisms in ecosystems in the Arctic and beyond.

  1. Rheological properties of concentrated solutions of carboxymethyl starch

    Directory of Open Access Journals (Sweden)

    Stojanović Željko

    2003-01-01

    Full Text Available Carboxymethyl starch was synthesized by the esterification of starch with monochloroacetic acid in ethanol as a reaction medium. Three samples of carboxymethyl starch having different degrees of substitution were prepared. The influence of temperature on the viscosity of concentrated carboxymethyl starch solutions, as well as the dynamic-mechanical properties of the concentrated solutions were investigated. The activation energy of viscous flow was determined and it was found that it decreased with increasing degree of substitution. The results of the dynamic-mechanical measurements showed that solutions of starch and carboxymethyl starches with higher degrees of substitution behave as gels. Values of the storage modulus in the rubbery plateau were used to calculate the molar masses between two points of physical crosslinking, the density of crosslinking and the distance between two points of crosslinking.

  2. Growth and Accumulation of Secondary Metabolites in Perilla as Affected by Photosynthetic Photon Flux Density and Electrical Conductivity of the Nutrient Solution

    Directory of Open Access Journals (Sweden)

    Na Lu

    2017-05-01

    Full Text Available The global demand for medicinal plants is increasing. The quality of plants grown outdoors, however, is difficult to control. Myriad environmental factors influence plant growth and directly impact biosynthetic pathways, thus affecting the secondary metabolism of bioactive compounds. Plant factories use artificial lighting to increase the quality of medicinal plants and stabilize production. Photosynthetic photon flux density (PPFD and electrical conductivity (EC of nutrient solutions are two important factors that substantially influence perilla (Perilla frutescens, Labiatae plant growth and quality. To identify suitable levels of PPFD and EC for perilla plants grown in a plant factory, the growth, photosynthesis, and accumulation of secondary metabolites in red and green perilla plants were measured at PPFD values of 100, 200, and 300 μmol m-2 s-1 in nutrient solutions with EC values of 1.0, 2.0, and 3.0 dS m-1. The results showed significant interactive effects between PPFD and EC for both the fresh and dry weights of green perilla, but not for red perilla. The fresh and dry weights of shoots and leafy areas were affected more by EC than by PPFD in green perilla, whereas they were affected more by PPFD than by EC in red perilla. Leaf net photosynthetic rates were increased as PPFD increased in both perilla varieties, regardless of EC. The perillaldehyde concentration (mg g-1 in red perilla was unaffected by the treatments, but accumulation in plants (mg per plant was significantly enhanced as the weight of dry leaves increased. Perillaldehyde concentrations in green perilla showed significant differences between combinations of the highest PPFD with the highest EC and the lowest PPFD with the lowest EC. Rosmarinic acid concentration (mg g-1 was increased in a combination of low EC and high PPFD conditions. Optimal cultivation conditions of red and green perilla in plant factory will be discussed in terms of plant growth and contents of

  3. Modeled sensitivity of Lake Michigan productivity and zooplankton to changing nutrient concentrations and quagga mussels

    Science.gov (United States)

    Pilcher, Darren J.; McKinley, Galen A.; Kralj, James; Bootsma, Harvey A.; Reavie, Euan D.

    2017-08-01

    The recent decline in Lake Michigan productivity is often attributed to filter feeding by invasive quagga mussels, but some studies also implicate reductions in lakewide nutrient concentrations. We use a 3-D coupled hydrodynamic-biogeochemical model to evaluate the effect of changing nutrient concentrations and quagga mussel filtering on phytoplankton production and phytoplankton and zooplankton biomass. Sensitivity experiments are used to assess the net effect of each change separately and in unison. Quagga mussels are found to have the greatest impact during periods of isothermal mixing, while nutrients have the greatest impact during thermal stratification. Quagga mussels also act to enhance spatial heterogeneity, particularly between nearshore-offshore regions. This effect produces a reversal in the gradient of nearshore-offshore productivity: from relatively greater nearshore productivity in the prequagga lake to relatively lesser nearshore productivity after quaggas. The combined impact of both processes drives substantial reductions in phytoplankton and zooplankton biomass, as well as significant modifications to the seasonality of surface water pCO2, particularly in nearshore regions where mussel grazing continues year-round. These results support growing concern that considerable losses of phytoplankton and zooplankton will yield concurrent losses at higher trophic levels. Comparisons to observed productivity suggest that both quagga mussel filtration and lower lakewide total phosphorus are necessary to accurately simulate recent changes in primary productivity in Lake Michigan.

  4. A portable concentrator for processing plutonium containing solutions

    International Nuclear Information System (INIS)

    Chamberlain, D.B.; Conner, C.; Chen, L.

    1995-01-01

    This report describes a horizontal, compact agitated-film concentrator called a Rototherm, manufactured by Artisan Industries, Inc. which can be used to process aqueous solutions of radioactive wastes containing plutonium. The unit is designed to concentrate liquid streams to a high-solid content slurry

  5. Nitrogen to phosphorus ratio of plant biomass versus soil solution in a tropical pioneer tree, Ficus insipida.

    Science.gov (United States)

    Garrish, Valerie; Cernusak, Lucas A; Winter, Klaus; Turner, Benjamin L

    2010-08-01

    It is commonly assumed that the nitrogen to phosphorus (N:P) ratio of a terrestrial plant reflects the relative availability of N and P in the soil in which the plant grows. Here, this was assessed for a tropical pioneer tree, Ficus insipida. Seedlings were grown in sand and irrigated with nutrient solutions containing N:P ratios ranging from 100. The experimental design further allowed investigation of physiological responses to N and P availability. Homeostatic control over N:P ratios was stronger in leaves than in stems or roots, suggesting that N:P ratios of stems and roots are more sensitive indicators of the relative availability of N and P at a site than N:P ratios of leaves. The leaf N:P ratio at which the largest plant dry mass and highest photosynthetic rates were achieved was approximately 11, whereas the corresponding whole-plant N:P ratio was approximately 6. Plant P concentration varied as a function of transpiration rate at constant nutrient solution P concentration, possibly due to transpiration-induced variation in the mass flow of P to root surfaces. The transpiration rate varied in response to nutrient solution N concentration, but not to nutrient solution P concentration, demonstrating nutritional control over transpiration by N but not P. Water-use efficiency varied as a function of N availability, but not as a function of P availability.

  6. Iodine uptake by spinach (Spinacia oleracea L.) plants grown in solution culture: effects of iodine species and solution concentrations.

    Science.gov (United States)

    Zhu, Y-G; Huang, Y-Z; Hu, Y; Liu, Y-X

    2003-04-01

    A hydroponic experiment was carried out to investigate the effects of iodine species and solution concentrations on iodine uptake by spinach (Spinacia oleracea L.). Five iodine concentrations (0, 1, 10, 50 and 100 microM) for iodate (IO(3)(-)) and iodide (I(-)) were used. Results show that higher concentrations of I(-) (> or =10 microM) had some detrimental effect on plant growth, while IO(3)(-) had little effect on the biomass production of spinach plants. Increases in iodine concentration in the growth solution significantly enhanced I concentrations in plant tissues. The detrimental effect of I(-) on plant growth was probably due to the excessively high accumulation of I in plant tissues. The solution-to-spinach leaf transfer factors (TF(leaf), fresh weight basis) for plants treated with iodide were between 14.2 and 20.7 at different solution concentrations of iodide; TF(leaf) for plants treated with iodate decreased gradually from 23.7 to 2.2 with increasing solution concentrations of iodate. The distribution coefficients (DCs) of I between leaves and roots were constantly higher for plants treated with iodate than those treated with iodide. DCs for plants treated with iodide increased with increasing solution concentrations of iodide, while DCs for plants treated with iodate (around 5.5) were similar across the range of solution concentrations of iodate used in this experiment. The implications of iodine accumulation in leafy vegetables in human iodine nutrition are also discussed. Copyright 2002 Elsevier Science Ltd.

  7. Source Material and Concentration of Wildfire-Produced Pyrogenic Carbon Influence Post-Fire Soil Nutrient Dynamics

    Directory of Open Access Journals (Sweden)

    Lucas A. Michelotti

    2015-04-01

    Full Text Available Pyrogenic carbon (PyC is produced by the thermal decomposition of organic matter in the absence of oxygen (O. PyC affects nutrient availability, may enhance post-fire nitrogen (N mineralization rates, and can be a significant carbon (C pool in fire-prone ecosystems. Our objectives were to characterize PyC produced by wildfires and examine the influence that contrasting types of PyC have on C and N mineralization rates. We determined C, N, O, and hydrogen (H concentrations and atomic ratios of charred bark (BK, charred pine cones (PC, and charred woody debris (WD using elemental analysis. We also incubated soil amended with BK, PC, and WD at two concentrations for 60 days to measure C and N mineralization rates. PC had greater H/C and O/C ratios than BK and WD, suggesting that PC may have a lesser aromatic component than BK and WD. C and N mineralization rates decreased with increasing PyC concentrations, and control samples produced more CO2 than soils amended with PyC. Soils with PC produced greater CO2 and had lower N mineralization rates than soils with BK or WD. These results demonstrate that PyC type and concentration have potential to impact nutrient dynamics and C flux to the atmosphere in post-fire forest soils.

  8. Isolated effects of external bath osmolality, solute concentration, and electrical charge on solute transport across articular cartilage.

    Science.gov (United States)

    Pouran, Behdad; Arbabi, Vahid; Zadpoor, Amir A; Weinans, Harrie

    2016-12-01

    The metabolic function of cartilage primarily depends on transport of solutes through diffusion mechanism. In the current study, we use contrast enhanced micro-computed tomography to determine equilibrium concentration of solutes through different cartilage zones and solute flux in the cartilage, using osteochondral plugs from equine femoral condyles. Diffusion experiments were performed with two solutes of different charge and approximately equal molecular weight, namely iodixanol (neutral) and ioxaglate (charge=-1) in order to isolate the effects of solute's charge on diffusion. Furthermore, solute concentrations as well as bath osmolality were changed to isolate the effects of steric hindrance on diffusion. Bath concentration and bath osmolality only had minor effects on the diffusion of the neutral solute through cartilage at the surface, middle and deep zones, indicating that the diffusion of the neutral solute was mainly Fickian. The negatively charged solute diffused considerably slower through cartilage than the neutral solute, indicating a large non-Fickian contribution in the diffusion of charged molecules. The numerical models determined maximum solute flux in the superficial zone up to a factor of 2.5 lower for the negatively charged solutes (charge=-1) as compared to the neutral solutes confirming the importance of charge-matrix interaction in diffusion of molecules across cartilage. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  9. Crescimento, desenvolvimento e produtividade do tomateiro cultivado em substrato com três concentrações de nitrogênio na solução nutritiva Growth, development and yield of tomato plants grown in substrate under three nitrogen concentrations of the nutrient solution

    Directory of Open Access Journals (Sweden)

    Jerônimo Luiz Andriolo

    2004-10-01

    e T3, com produtividade máxima estimada de 7,8kg m-2 na dose de 9,3mmolN L-1. Concluiu-se que a concentração de N na solução nutritiva afetou o crescimento e a produtividade da cultura do tomateiro em substrato, porém não foi observada resposta similar nos dois ciclos de cultivo.The effect of three N concentrations of the nutrient solution on growth and yield of tomato plants grown in substrate was determined in autumn and spring growing periods. Two experiments were conducted inside a polyethylene tunnel, at Departamento de Fitotecnia - UFSM, using the hybrid Monte Carlo. Sowing was made on February 8 and on July 5, 2002, and planting inside the tunnel 36 and 40 days later, in autumn and spring, respectively. Plants were grown in plastic bags filled with 5.5dm³ of commercial substrate (Plantmax®, with one plant per bag and a plant density of 3.3 plants m-2. Nutrients were supplied to plants by a complete nutrient solution, with the following composition, in mmol L-1: 5.5 of KNO3; 1.3 of KH2PO4; 2.75 of Ca(NO32; 0.75 of MgSO4, with iron chelate and micronutrients. The treatment T2 was the nutrient solution described above, with 11.0mmolN L-1. For treatment T1, the N concentration of the nutrient solution was reduced to 5.5mmolN L-1, whereas for T3 it was increased to 15.16mmolN L-1. A randomised experimental design was used, with four replications and 15 plants per plot. Plants were harvested at 33, 48, 55, 62, 69, 76 and 83 days after planting (DAP in autumn, and at 55, 62, 69, 78, 85 and 92 DAP in spring, to measure plant growth and development. Crop yield was determined by fresh weight of fruits. The number of leaves was lower on T3 plants in autumn and spring, whereas the number of fruits was higher on T1 plants in spring. The dynamics of fruit dry mass accumulation did not show significant differences among treatments in autumn. In spring, the lowest value of this variable was recorded on T3 plants. Mean values of fresh fruit weight reached 5.4; 5

  10. [Effects of nitrogen deposition on the concentration and spectral characteristics of dissolved organic matter in soil solution in a young Cunninghamia lanceolata plantation.

    Science.gov (United States)

    Yuan, Xiao Chun; Chen, Yue Min; Yuan, Shuo; Zheng, Wei; Si, You Tao; Yuan, Zhi Peng; Lin, Wei Sheng; Yang, Yu Sheng

    2017-01-01

    To study the effects of nitrogen deposition on the concentration and spectral characteristics of dissolved organic matter (DOM) in the forest soil solution from the subtropical Cunninghamia lanceolata plantation, using negative pressure sampling method, the dynamics of DOM in soil solutions from 0-15 and 15-30 cm soil layer was monitored for two years and the spectroscopic features of DOM were analyzed. The results showed that nitrogen deposition significantly reduced the concentration of dissolved organic carbon (DOC), and increased the aromatic index (AI) and the humic index (HIX), but had no significant effect on dissolved organic nitrogen (DON) concentration in both soil layers. There was obvious seasonal variation in DOM concentration of the soil solution, which was prominently higher in summer and autumn than in spring and winter.Fourier-transform infrared (FTIR) absorption spectrometry indicated that the DOM in forest soil solution had absorption peaks in the similar position of six regions, being the highest in wave number of 1145-1149 cm -1 . Three-dimensional fluorescence spectra indicated that DOM was mainly consisted of protein-like substances (Ex/Em=230 nm/300 nm) and microbial degradation products (Ex/Em=275 nm/300 nm). The availability of protein-like substances from 0-15 cm soil layer was reduced in the nitrogen treatments. Nitrogen deposition significantly reduced the concentration of DOC in soil solution, maybe largely by reducing soil pH, inhibiting soil carbon mineralization and stimulating plant growth. In particular, the decline of DOC concentration in the surface layer was due to the production inhibition of the protein-like substances and carboxylic acids. Short-term nitrogen deposition might be beneficial to the maintenance of soil fertility, while the long-term accumulation of nitrogen deposition might lead to the hard utilization of soil nutrients.

  11. Methylparaben concentration in commercial Brazilian local anesthetics solutions

    Directory of Open Access Journals (Sweden)

    Gustavo Henrique Rodriguez da Silva

    2012-08-01

    Full Text Available OBJECTIVE: To detect the presence and concentration of methylparaben in cartridges of commercial Brazilian local anesthetics. MATERIAL AND METHODS: Twelve commercial brands (4 in glass and 8 in plastic cartridges of local anesthetic solutions for use in dentistry were purchased from the Brazilian market and analyzed. Different lots of the commercial brands were obtained in different Brazilian cities (Piracicaba, Campinas and São Paulo. Separation was performed using high performance liquid chromatography (HPLC with UV-Vis detector. The mobile phase used was acetonitrile:water (75:25 - v/v, pH 4.5, adjusted with acetic acid at a flow rate of 1.0 ml.min-1. RESULTS: When detected in the solutions, the methylparaben concentration ranged from 0.01% (m/v to 0.16% (m/v. One glass and all plastic cartridges presented methylparaben. CONCLUSION: 1. Methylparaben concentration varied among solutions from different manufacturers, and it was not indicated in the drug package inserts; 2. Since the presence of methylparaben in dental anesthetics is not regulated by the Brazilian National Health Surveillance Agency (ANVISA and this substance could cause allergic reactions, it is important to alert dentists about its possible presence.

  12. Hydrogen-bonded structure in highly concentrated aqueous LiBr solutions

    International Nuclear Information System (INIS)

    Imano, Masahiro; Kameda, Yasuo; Usuki, Takeshi; Uemura, Osamu

    2001-01-01

    Neutron diffraction measurements were carried out for H/D isotopically substituted aqueous 10, 25 and 33 mol% LiBr solutions in order to obtain structural information on the intermolecular hydrogen bonds among water molecules in highly concentrated aqueous solutions. Observed scattering cross sections for D 2 O (99.9 % D), 0 H 2 O(35.9 % D) and 0-2 H 2 O(68.0 % D) solutions were combined to deduce partial structure factors, a HH (Q), a XH (Q) and a XX (Q) (X: O, Br and Li). The least squares fitting analysis was applied to the observed partial structure factors to determine the nearest neighbor interatomic distance, root-mean-square amplitude and coordination number. Intermolecular distances, r OH =1.91(1) A, r HH =2.38(1) A and r OO =3.02(1) A, between the nearest neighbor water molecules, were obtained for the 10 mol% LiBr solution. On the other hand, the intermolecular O···H interaction was found to almost disappear in concentrated 25 and 33 mol% LiBr solutions. The result implies that the hydrogen-bonded network is completely broken in highly concentrated aqueous LiBr solutions. (author)

  13. Seawater-driven forward osmosis for enriching nitrogen and phosphorous in treated municipal wastewater: effect of membrane properties and feed solution chemistry.

    Science.gov (United States)

    Xue, Wenchao; Tobino, Tomohiro; Nakajima, Fumiyuki; Yamamoto, Kazuo

    2015-02-01

    Seawater-driven forward osmosis (FO) is considered to be a novel strategy to concentrate nutrients in treated municipal wastewater for further recovery as well as simultaneous discharge of highly purified wastewater into the sea with low cost. As a preliminary test, the performance of FO membranes in concentrating nutrients was investigated by both batch experiments and model simulation approaches. With synthetic seawater as the draw solution, the dissolved organic carbon, phosphate, and ammonia in the effluent from a membrane bioreactor (MBR) treating municipal wastewater were 2.3-fold, 2.3-fold, and 2.1-fold, respectively, concentrated by the FO process with approximately 57% of water reduction. Most of the dissolved components, including trace metals in the MBR effluent, were highly retained (>80%) in the feed side, indicating high water quality of permeate to be discharged. The effect of membrane properties on the nutrient enrichment performance was investigated by comparing three types of FO membranes. Interestingly, a polyamide membrane possessing a high negative charge demonstrated a poor capability of retaining ammonia, which was hypothesized because of an ion exchange-like mechanism across the membrane prompted by the high ionic concentration of the draw solution. A feed solution pH of 7 was demonstrated to be an optimum condition for improving the overall retention of nutrients, especially for ammonia because of the pH-dependent speciation of ammonia/ammonium forms. The modeling results showed that higher than 10-fold concentrations of ammonia and phosphate are achievable by seawater-driven FO with a draw solution to feed solution volume ratio of 2:1. The enriched municipal wastewater contains nitrogen and phosphorous concentrations comparable with typical animal wastewater and anaerobic digestion effluent, which are used for direct nutrient recovery. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Synergistic effects and optimization of nitrogen and phosphorus concentrations on the growth and nutrient uptake of a freshwater Chlorella vulgaris.

    Science.gov (United States)

    Alketife, Ahmed M; Judd, Simon; Znad, Hussein

    2017-01-01

    The synergistic effects and optimization of nitrogen (N) and phosphorus (P) concentrations on the growth of Chlorella vulgaris (CCAP 211/11B, CS-42) and nutrient removal have been investigated under different concentrations of N (0-56 mg/L) and P (0-19 mg/L). The study showed that N/P ratio has a crucial effect on the biomass growth and nutrient removal. When N/P=10, a complete P and N removal was achieved at the end of cultivation with specific growth rate (SGR) of 1 d -1 and biomass concentration of 1.58 g/L. It was also observed that when the N content <2.5 mg/L, the SGR significantly reduced from 1.04 to 0.23 d -1 and the maximum biomass produced was decreased more than three-fold to 0.5 g/L. The Box-Behnken experimental design and response surface method were used to study the effects of the initial concentrations (P, N and C) on P and N removal efficiencies. The optimized P, N and C concentrations supporting 100% removal of both P and N at an SGR of 0.95 were 7, 55 and 10 mg/L respectively, with desirability value of 0.94. The results and analysis obtained could be very useful when applying the microalgae for efficient wastewater treatment and nutrient removal.

  15. Effects of Nitrogen and Nutrient Removal on Nitrate Accumulation and Growth Characteristics of Spinach (Spinacia oleraceae L.

    Directory of Open Access Journals (Sweden)

    mohammadsadegh sadeghi

    2017-12-01

    was conducted with twolevels of removal (removal of nutrient one week before harvest or not to remove and fourlevels of nitrogen (25, 50, 100 and 200 mg/l with sixreplications. During the growing season in the greenhouse, temperature was fixed between 24-27 °C and photoperiod of 16 hours of light and 8 hours of darkness. The measured traits were root fresh and dry weight, shoot fresh and dry weight, Fv/Fm ratio, and chlorophyll index, number of leaf per plant, leaf area, nitrate and total nitrogen. Results and Discussion: The results of this experiment showed that increasingnitrogen concentration from 25 to 200 mg/l increased shoot dry weight, number of leaves and leaf area, by 22.00, 7.26, 4.79 and 14.00 fold, respectively. Nitrogen also increased Fv/Fm and chlorophyll index. Nutrient removal in a week before harvest had no significant effect on fresh and dry weight of shoots and roots, number of leaves,leaf area, chlorophyll index and Fv/Fm. Increasing concentrations of nitrogen increased nitrate and total nitrogen in petiole while removing the nutrient solution in a week before harvest significantly decreased amounts of the above-mentioned traits. Nutrient solution removal is an appropriate strategy to reduce nitrate accumulation in spinach that has no effect on yield loss. Conclusions: The results showed that increasing the concentration of nitrogen increased plant growth indicators such as shoot fresh and dry weight, root fresh and dry weight, leaf area and number of leaf per plants, so that the greatest increase was obtained from concentration of 200 mg/lit. Increasing the concentration of nitrogen enhanced nitrate and total nitrogen of petiole so that the highest concentration of nitrate and total nitrogen was observed in200 mg/lit nitrogen. Nutrient solution removal in a week before the harvest had a significant effect in reducing all traits but it decreased nitrate accumulation and total nitrogen of petiole significantly. At the end of the experiment, it was

  16. Energy-neutral sustainable nutrient recovery incorporated with the wastewater purification process in an enlarged microbial nutrient recovery cell

    Science.gov (United States)

    Sun, Dongya; Gao, Yifan; Hou, Dianxun; Zuo, Kuichang; Chen, Xi; Liang, Peng; Zhang, Xiaoyuan; Ren, Zhiyong Jason; Huang, Xia

    2018-04-01

    Recovery of nutrient resources from the wastewater is now an inevitable strategy to maintain the supply of both nutrient and water for our huge population. While the intensive energy consumption in conventional nutrient recovery technologies still remained as the bottleneck towards the sustainable nutrient recycle. This study proposed an enlarged microbial nutrient recovery cell (EMNRC) which was powered by the energy contained in wastewater and achieved multi-cycle nutrient recovery incorporated with in situ wastewater treatment. With the optimal recovery solution of 3 g/L NaCl and the optimal volume ratio of wastewater to recovery solution of 10:1, >89% of phosphorus and >62% of ammonium nitrogen were recovered into struvite. An extremely low water input ratio of water. It was proved the EMNRC system was a promising technology which could utilize the chemical energy contained in wastewater itself and energy-neutrally recover nutrient during the continuous wastewater purification process.

  17. Concentration Fluctuations and Capacitive Response in Dense Ionic Solutions.

    Science.gov (United States)

    Uralcan, Betul; Aksay, Ilhan A; Debenedetti, Pablo G; Limmer, David T

    2016-07-07

    We use molecular dynamics simulations in a constant potential ensemble to study the effects of solution composition on the electrochemical response of a double layer capacitor. We find that the capacitance first increases with ion concentration following its expected ideal solution behavior but decreases upon approaching a pure ionic liquid in agreement with recent experimental observations. The nonmonotonic behavior of the capacitance as a function of ion concentration results from the competition between the independent motion of solvated ions in the dilute regime and solvation fluctuations in the concentrated regime. Mirroring the capacitance, we find that the characteristic decay length of charge density correlations away from the electrode is also nonmonotonic. The correlation length first decreases with ion concentration as a result of better electrostatic screening but increases with ion concentration as a result of enhanced steric interactions. When charge fluctuations induced by correlated ion-solvent fluctuations are large relative to those induced by the pure ionic liquid, such capacitive behavior is expected to be generic.

  18. Anomalous concentration gradient in NaI solutions inadvertently frozen in transit

    International Nuclear Information System (INIS)

    Billinghurst, M.W.; Abrams, D.N.; Coutts, A.D.

    1990-01-01

    Therapeutic doses of iodine-131 ( 131 I) are frequently dispensed volumetrically from a stock vial containing a solution of sodium iodide. During the winter months the authors have observed that initial aliquots do not always have the same radioactive concentration as that calculated for the bulk solution. In order to evaluate the cause and extent of this problem, they prepared a stock solution of low radioactive concentration sodium iodide with the same concentration of sodium thiosulfate and pH as that in the stock therapeutic iodine vial. Aliquots of this solution were transferred to plastic tubes and were stored at various temperatures. These results clearly show that when there is a risk of freezing during transportation of therapeutic solutions of sodium iodide it is essential to physically mix the liquid once thawing is complete if therapeutic doses are to be dispensed accurately on a volume basis

  19. Whispering Gallery Mode Based Optical Fiber Sensor for Measuring Concentration of Salt Solution

    Directory of Open Access Journals (Sweden)

    Chia-Chin Chiang

    2013-01-01

    Full Text Available An optical fiber solution-concentration sensor based on whispering gallery mode (WGM is proposed in this paper. The WGM solution-concentration sensors were used to measure salt solutions, in which the concentrations ranged from 1% to 25% and the wavelength drifted from the left to the right. The experimental results showed an average sensitivity of approximately 0.372 nm/% and an R2 linearity of 0.8835. The proposed WGM sensors are of low cost, feasible for mass production, and durable for solution-concentration sensing.

  20. Interaction between copper and radiocesium in Indian mustard and sunflower grown in the hydroponic solution

    International Nuclear Information System (INIS)

    Shirong Tang; Xiaochang Wang

    2002-01-01

    Both Indian mustard and sunflower were grown in a hydroponic solution treated with different concentration activities of 134 Cs or with different amounts of copper or with both in order to investigate the interaction between copper and radiocesium. It was found that 134 Cs activity concentration applied in the nutrient solution exerted more influence on the uptake and translocation of copper by Indian mustard than by sunflower. Indian mustard grown in hydroponic solution containing certain levels of copper and being treated with higher 134 Cs activity concentration showed higher uptake of copper than sunflower. However, in the case of root copper concentrations, sunflower showed significantly higher copper immobilization by roots than Indian mustard. It was also found that the presence of copper the the hydroponic solution did modify radiocesium uptake by both species. The application of 1 mg/l in the growth medium could greatly increase the uptake of 134 Cs by both species. With 3 mg/l concentration of copper amended to the solution, the accumulation of 134 Cs by both species was decreased compared to the 1 mg/l copper treatment. These lines of evidence show that there is stronger interaction between copper and radiocesium in Indian mustard than in sunflower during the root uptake through nutrient solution. (author)

  1. Linking nutrient enrichment, sediment erodibility and biofilms

    Science.gov (United States)

    Conrad, B.; Mahon, R.; Sojka, S. L.

    2014-12-01

    Sediment movement in coastal lagoons affects nutrient flux and primary producer growth. Previous research has shown that sediment erodibility is affected by biofilm concentration and that growth of benthic organisms, which produce biofilm, is affected by nutrient enrichment. However, researchers have not examined possible links between nutrient addition and sediment erodibility. We manipulated nutrient levels in the water column of 16 microcosms filled with homogenized sediment from a shallow coastal lagoon and artificial seawater to determine the effects on biofilm growth, measured through chlorophyll a and colloidal carbohydrate concentrations. Erosion tests using a Gust microcosm were conducted to determine the relationship between sediment erodibility and biofilm concentration. Results show that carbohydrate levels decreased with increasing nutrient enrichment and were unrelated to chlorophyll concentrations and erodibility. The nutrient levels did not predictably affect the chlorophyll levels, with lower chlorophyll concentrations in the control and medium enrichment treatments than the low and high enrichment treatments. Controls on biofilm growth are still unclear and the assumed relationship between carbohydrates and erodibility may be invalid. Understanding how biofilms respond to nutrient enrichment and subsequent effects on sediment erodibility is essential for protecting and restoring shallow coastal systems.

  2. EPA's Review of Concentrated Animal Feeding Operation (CAFO) Permits and Nutrient Management Plans in the Chesapeake Bay Watershed

    Science.gov (United States)

    Starting in 2013, EPA conducted reviews of Concentrated Animal Feeding Operations (CAFOs) permits and nutrient management plans (NMPs) in six of the Bay jurisdictions (Delaware, Maryland, New York, Pennsylvania, Virginia and West Virginia).

  3. Produtividade e qualidade de frutos de meloeiro cultivado em substrato com três doses de solução nutritiva Yield and quality of muskmelon fruits grown in substrate under three concentrations of the nutrient solution

    Directory of Open Access Journals (Sweden)

    Jerônimo Luiz Andriolo

    2005-08-01

    .0 K+ ; 5.01 Ca++ ; 2.25 Mg++ ; 2.25 SO4-, with added micronutrients. For treatments T1 and T3, quantities of fertilizers from T2 were multiplied by a factor of 0.5 and 2, respectively. LAI values at the ending date were 1.99; 2.22 and 2.28 m² m-2 for T1, T2 and T3, respectively, T1 differing significantly from T2 and T3. Fruit yield reached 56.2; 65.0 and 65.9 Mg++ ha-1, for T1, T2 and T3, respectively. Maximum fruit yield was estimated by a nutrient concentration of 44.1 mmol L-1, corresponding to the following composition of the nutrient solution, in mmol L-1: 19.5 of NO3-; 1.35 of H2PO4-; 9.0 of K+; 7.51 of Ca++; 3.37 of Mg++; 3.37 of SO4-, and in mumol L-1: 50.25 of Fe; 22.5 of Mn; 3.45 of Zn; 1.5 of Cu; 22.5 of B e 0.78 of Mo. Similar results were observed for fruit quality variables.

  4. Soil solution Ni concentrations over which Kd is constant in Japanese agricultural soils

    International Nuclear Information System (INIS)

    Kamei-Ishikawa, Nao; Uchida, Shigeo; Tagami, Keiko; Satta, Naoya

    2011-01-01

    The soil-soil solution distribution coefficient (K d ) is one of the most important parameters required by the models used for radioactive waste disposal environmental impact assessment. The models are generally based on the assumption that K d is independent of the element concentration in soil solution. However, at high soil solution concentrations, this assumption is not valid. Since the sorption of most radionuclides in soil is influenced by their stable isotope concentrations, it is necessary to consider if the range in the naturally occurring stable isotope concentrations in the soil solution is within the range over which K d is valid. The objective of this study was to determine if the K d for nickel (Ni) can be assumed to be constant over the ranges of stable Ni concentration in five main Japanese agricultural soil types. To obtain Ni sorption isotherms for five Japanese soils, two types of batch sorption tests were carried out using radioactive 63 Ni as a tracer. The concentration at which the relationship between soil and soil solution concentration became nonlinear was determined using the two types of sorption isotherms: the Langmuir and Henry isotherms. The result showed that the Ni concentration in the soil solution at which the assumption of a constant K d becomes valid is at least ten times higher than the natural Ni concentrations in solutions of Japanese agricultural soils. This value is sufficient to treat K d for Ni as constant for environmental impact assessment models for the disposal of radioactive waste. (author)

  5. Use of hydroponics culture to assess nutrient supply by treated wastewater.

    Science.gov (United States)

    Adrover, Maria; Moyà, Gabriel; Vadell, Jaume

    2013-09-30

    The use of treated wastewater for irrigation is increasing, especially in those areas where water resources are limited. Treated wastewaters contain nutrients that are useful for plant growth and help to reduce fertilizers needs. Nutrient content of these waters depends on the treatment system. Nutrient supply by a treated wastewater from a conventional treatment plant (CWW) and a lagooned wastewater from the campus of the University of Balearic Islands (LWW) was tested in an experiment in hydroponics conditions. Half-strength Hoagland nutrient solution (HNS) was used as a control. Barley (Hordeum vulgare L.) seedlings were grown in 4 L containers filled with the three types of water. Four weeks after planting, barley was harvested and root and shoot biomass was measured. N, P, K, Ca, Mg, Na and Fe contents were determined in both tissues and heavy metal concentrations were analysed in shoots. N, P and K concentrations were lower in LWW than in CWW, while HNS had the highest nutrient concentration. Dry weight barley production was reduced in CWW and LWW treatments to 49% and 17%, respectively, comparing to HNS. However, to a lesser extent, reduction was found in shoot and root N content. Treated wastewater increased Na content in shoots and roots of barley and Ca and Cr content in shoots. However, heavy metals content was lower than toxic levels in all the cases. Although treated wastewater is an interesting water resource, additional fertilization is needed to maintain a high productivity in barley seedlings. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. The potential use of treated brewery effluent as a water and nutrient source in irrigated crop production

    Directory of Open Access Journals (Sweden)

    Richard P. Taylor

    2018-06-01

    Full Text Available Brewery effluent (BE needs to be treated before it can be released into the environment, reused or used in down-stream activities. This study demonstrated that anaerobic digestion (AD followed by treatment in an integrated tertiary effluent treatment system transformed BE into a suitable solution for crop irrigation. Brewery effluent can be used to improve crop yields: Cabbage (Brassica oleracea cv. Star 3301, grew significantly larger when irrigated with post-AD, post-primary-facultative-pond (PFP effluent, compared with those irrigated with post-constructed-wetland (CW effluent or tap water only (p < 0.0001. However, cabbage yield when grown using BE was 13% lower than that irrigated with a nutrient-solution and fresh water; the electrical conductivity of BE (3019.05 ± 48.72 µs/cm2 may have been responsible for this. Post-CW and post-high-rate-algal-pond (HRAP BE was least suitable due to their higher conductivity and lower nutrient concentration. After three months, soils irrigated with post-AD and post-PFP BE had a significantly higher sodium concentration and sodium adsorption ratio (3919 ± 94.77 & 8.18 ± 0.17 mg/kg than soil irrigated with a commercial nutrient-solution (920.58 ± 27.46 & 2.20 ± 0.05 mg/kg. However, this was not accompanied by a deterioration in the soil's hydro-physical properties, nor a change in the metabolic community structure of the soil. The benefits of developing this nutrient and water resource could contribute to cost-reductions at the brewery, more efficient water, nutrient and energy management, and job creation. Future studies should investigate methods to reduce the build-up of salt in the soil when treated BE is used to irrigate crops. Keywords: Wastewater irrigation, Nutrient recovery, Agriculture, Brewery effluent

  7. Soluble organic nutrient fluxes

    Science.gov (United States)

    Robert G. Qualls; Bruce L. Haines; Wayne Swank

    2014-01-01

    Our objectives in this study were (i) compare fluxes of the dissolved organic nutrients dissolved organic carbon (DOC), DON, and dissolved organic phosphorus (DOP) in a clearcut area and an adjacent mature reference area. (ii) determine whether concentrations of dissolved organic nutrients or inorganic nutrients were greater in clearcut areas than in reference areas,...

  8. Changing climate and nutrient transfers: Evidence from high temporal resolution concentration-flow dynamics in headwater catchments.

    Science.gov (United States)

    Ockenden, M C; Deasy, C E; Benskin, C McW H; Beven, K J; Burke, S; Collins, A L; Evans, R; Falloon, P D; Forber, K J; Hiscock, K M; Hollaway, M J; Kahana, R; Macleod, C J A; Reaney, S M; Snell, M A; Villamizar, M L; Wearing, C; Withers, P J A; Zhou, J G; Haygarth, P M

    2016-04-01

    We hypothesise that climate change, together with intensive agricultural systems, will increase the transfer of pollutants from land to water and impact on stream health. This study builds, for the first time, an integrated assessment of nutrient transfers, bringing together a) high-frequency data from the outlets of two surface water-dominated, headwater (~10km(2)) agricultural catchments, b) event-by-event analysis of nutrient transfers, c) concentration duration curves for comparison with EU Water Framework Directive water quality targets, d) event analysis of location-specific, sub-daily rainfall projections (UKCP, 2009), and e) a linear model relating storm rainfall to phosphorus load. These components, in combination, bring innovation and new insight into the estimation of future phosphorus transfers, which was not available from individual components. The data demonstrated two features of particular concern for climate change impacts. Firstly, the bulk of the suspended sediment and total phosphorus (TP) load (greater than 90% and 80% respectively) was transferred during the highest discharge events. The linear model of rainfall-driven TP transfers estimated that, with the projected increase in winter rainfall (+8% to +17% in the catchments by 2050s), annual event loads might increase by around 9% on average, if agricultural practices remain unchanged. Secondly, events following dry periods of several weeks, particularly in summer, were responsible for high concentrations of phosphorus, but relatively low loads. The high concentrations, associated with low flow, could become more frequent or last longer in the future, with a corresponding increase in the length of time that threshold concentrations (e.g. for water quality status) are exceeded. The results suggest that in order to build resilience in stream health and help mitigate potential increases in diffuse agricultural water pollution due to climate change, land management practices should target

  9. Nutrient and sediment concentrations and loads in the Steele Bayou Basin, northwestern Mississippi, 2010–14

    Science.gov (United States)

    Hicks, Matthew B.; Murphy, Jennifer C.; Stocks, Shane J.

    2017-06-01

    The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers-Vicksburg District, monitored streamflow, water quality, and sediment at two stations on the Steele Bayou in northwestern Mississippi from October 2010 through September 2014 to characterize nutrient and sediment concentrations and loads in areas where substantial implementation of conservation efforts have been implemented. The motivation for this effort was to quantify improvements, or lack thereof, in water quality in the Steele Bayou watershed as a result of implementing large- and small-scale best-management practices aimed at reducing nutrient and sediment concentrations and loads. The results of this study document the hydrologic, water-quality, and sedimentation status of these basins following over two decades of ongoing implementation of conservation practices.Results from this study indicate the two Steele Bayou stations have comparable loads and yields of total nitrogen, phosphorus, and suspended sediment when compared to other agricultural basins in the southeastern and central United States. However, nitrate plus nitrite yields from basins in the Mississippi River alluvial plain, including the Steele Bayou Basin, are generally lower than other agricultural basins in the southeastern and central United States.Seasonal variation in nutrient and sediment loads was observed at both stations and for most constituents. About 50 percent of the total annual nutrient and sediment load was observed during the spring (February through May) and between 25 and 50 percent was observed during late fall and winter (October through January). These seasonal patterns probably reflect a combination of seasonal patterns in precipitation, runoff, streamflow, and in the timing of fertilizer application.Median concentrations of total nitrogen, nitrate plus nitrite, total phosphorus, orthophosphate, and suspended sediment were slightly higher at the upstream station, Steele Bayou near Glen Allan

  10. Microrheology of concentrated DNA solutions using optical tweezers

    Indian Academy of Sciences (India)

    . In this work, we report the determination of microrheological properties of concentrated, double-stranded calf thymus DNA (CT-DNA) solutions using passive, laser-scattering based particle-tracking methodology. From power spectral analysis, ...

  11. Foliar nutrient status of Pinus ponderosa exposed to ozone and acid rain

    International Nuclear Information System (INIS)

    Anderson, P.D.; Houpis, J.L.J.

    1991-01-01

    A direct effect of foliar exposure to acid rain may be increased leaching of nutrient elements. Ozone exposure, through degradation of the cuticle and cellular membranes, may also result in increased nutrient leaching. To test these hypotheses, the foliar concentrations of 13 nutrient elements were monitored for mature branches of three clones of Pinus ponderosa exposed to ozone and/or acid rain. The three clones represented three distinct levels of phenotypic vigor. Branches were exposed to charcoal filtered, ambient, or 2 x ambient concentrations of ozone and received no acid rain (NAP), pH 5.1 rain (5.1), or pH 3.0 (3.0) rain. Following 10 months of continuous ozone exposure and 3 months of weekly rain applications, the concentrations of P and Mg differed significantly among rain treatments with a ranking of: 5.1 < NAP < 3.0. The S concentration increased with rain application regardless of pH. For the clones of moderate and low vigor, the concentration of N decreased with increasing rain acidity. There was no evidence of significant ozone or ozone x acid rain response. Among the three families, high phenotypic vigor was associated with significantly greater concentrations of N, P, K, Mg, B and An. These results indicate generally negligible leaching as a result of exposure to acid rain and/or ozone for one growing season. Increases in foliar concentrations of S, Mg and P are possibly the result of evaporative surface deposition from the rain solution

  12. Nutrient and secondary metabolite concentrations in a savanna are independently affected by large herbivores and shoot growth rate

    CSIR Research Space (South Africa)

    Scogings, PF

    2014-01-01

    Full Text Available Carbon-based secondary metabolites (CBSMs) such as tannins are assumed to function as plant defences against herbivores. CBSMs are thought to be inversely related to growth rate and nutrient concentrations because a physiological trade-off exists...

  13. Problems of evaluating isotope analysis of concentrated salt solutions in potash mines

    International Nuclear Information System (INIS)

    Schmiedl, H.D.

    1980-01-01

    Three problems of quantitative evaluation of analytic D and 18 O isotope data of concentrated salt solutions are discussed: (1) Consideration of the influence of admixtures of hydrated salts in determining meteoric or marine water fractions in a concentrated salt solution, (2) analytic accuracy and detection limits in determining meteoric water in salt solutions, and (3) processes of isotopic exchange with reservoir rock and sample matrix

  14. Oxygen and diverse nutrients influence the water kefir fermentation process.

    Science.gov (United States)

    Laureys, David; Aerts, Maarten; Vandamme, Peter; De Vuyst, Luc

    2018-08-01

    Eight water kefir fermentation series differing in the presence of oxygen, the nutrient concentration, and the nutrient source were studied during eight consecutive backslopping steps. The presence of oxygen allowed the proliferation of acetic acid bacteria, resulting in high concentrations of acetic acid, and decreased the relative abundance of Bifidobacterium aquikefiri. Low nutrient concentrations resulted in slow water kefir fermentation and high pH values, which allowed the growth of Comamonas testosteroni/thiooxydans. Further, low nutrient concentrations favored the growth of Lactobacillus hilgardii and Dekkera bruxellensis, whereas high nutrient concentrations favored the growth of Lactobacillus nagelii and Saccharomyces cerevisiae. Dried figs, dried apricots, and raisins resulted in stable water kefir fermentation. Water kefir fermentation with dried apricots resulted in the highest pH and water kefir grain growth, whereas that with raisins resulted in the lowest pH and water kefir grain growth. Further, water kefir fermentation with raisins resembled fermentations with low nutrient concentrations, that with dried apricots resembled fermentations with normal nutrient concentrations, and that with fresh figs or a mixture of yeast extract and peptone resembled fermentations with high nutrient concentrations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Differences in nutrient concentrations and resources between seagrass communities on carbonate and terrigenous sediments in South Sulawesi, Indonesia

    NARCIS (Netherlands)

    Erftemeijer, P.L.A.

    1994-01-01

    Water column, sediment and plant parameters were studied in six tropical seagrass beds in South Sulawesi, Indonesia, to evaluate the relation between seagrass bed nutrient concentrations and sediment type. Coastal seagrass beds on terrigenous sediments had considerably higher biomass of

  16. Contribution of fish farming to the nutrient loading of the Mediterranean

    Directory of Open Access Journals (Sweden)

    Ioannis Karakassis

    2005-06-01

    Full Text Available Mediterranean fish farming has grown exponentially during the last 20 years. Although there is little evidence of the impact on the trophy status around fish farms, there are concerns that the release of solute wastes from aquaculture might affect larger scales in the ecosystem by changing the nutrient load. After combining information from various sources on waste production and on nutrient loads, it was concluded that the overall N and P waste from fish farms in the Mediterranean represents less than 5% of the total annual anthropogenic discharge, and the overall annual increase in P and N pools in the Mediterranean, under a production rate of 150000 tons, is less than 0.01%. The proportion of fish farming discharged nutrients was slightly higher in the eastern Mediterranean. A simple model was used to assess the long-term effects of nutrients released from various sources taking into account the water renewal rate in the Mediterranean. We conclude that, in the long term, fish farm waste could cause a 1% increase in nutrient concentrations in contrast to other anthropogenic activities which might double the Mediterranean nutrient pool.

  17. Concentração de potássio na solução nutritiva e a qualidade e número de frutos de melão por planta em hidroponia Potassium concentration in nutrient solution and quality and number of fruits of melon, cultivated in hidroponic

    Directory of Open Access Journals (Sweden)

    Caciana Cavalcanti Costa

    2004-06-01

    Full Text Available O experimento foi conduzido em hidroponia (NFT no período de junho a novembro de 2001, na FCAV-UNESP em Jaboticabal-SP, situada a 21º15’ 22" Sul, 48º18’58" Oeste, e altitude de 575 metros. O híbrido Bônus n0 2 foi cultivado em blocos casualizados, em esquema de parcelas subdivididas, com seis repetições. Os elementos avaliados foram número de frutos por planta (2, 3, 4 e fixação livre e concentração de potássio na solução nutritiva (66; 115,5; 165 e 247,5mg L-1. O experimento teve como objetivo avaliar a concentração de potássio na solução nutritiva e número de frutos por planta sobre a qualidade dos frutos do meloeiro. Concentrações maiores do que 66mg L-1 de potássio na solução nutritiva não promoveram incrementos nas características de qualidade dos frutos do meloeiro como: teor de sólidos solúveis médio de todos os frutos da planta, do segundo fruto, da acidez total titulável média de todos os frutos da planta, do primeiro fruto, do segundo fruto, do índice de maturação, da espessura da polpa e do índice de formato dos frutos. Frutos oriundos de plantas de melão com dois frutos apresentaram maior teor de sólidos solúveis e acidez total titulável, independente da concentração de potássio na solução nutritiva. O maior número de frutos por planta reduziu a espessura do mesocarpo dos frutos.The experiment was carried out in Jaboticabal-SP. The hybrid Bonus n0 2 was cropped in randomized blocks design, in split-plot scheme and six replications. Fruit number per plant (2, 3, 4 e free fruit set and potassium concentration in the nutrient solution (66, 115.5, 165 and 247.5mg L-1 were the studied factors. The increase of potassium concentration in the nutrient solution did not promote increase melon fruit quality characteristics such as: average soluble solid content from all plant fruits or that of the second fruit; average total tritratable acidity from all plant fruits and that of the first or

  18. Uptake of radiocaesium by lettuce crops: the effect of K in soil solution

    International Nuclear Information System (INIS)

    Waegeneers, N.; Camps I Vila, M.; Smolders, E.; Merckx, R.; Sauras, T.; Madoz-Escande, C.

    1998-01-01

    The effect of varying K supply on 137 Cs uptake by lettuce (Lactuca sativa, cv. Batavia, Gloire du Dauphine) was studied in solution culture, in a potted soil experiment and in a greenhouse lysimeter experiment under close-to-real conditions. Lettuce was grown for 13 days in nutrient solution spiked with 137 Cs. Treatments were four concentrations of potassium in solution (25, 50, 250, and 1000 μM). Yields were marginally affected by K supply. The 137 Cs concentration factor (CF, ml/g) decreased 66-fold in the shoot and 432-fold in the roots over the whole K concentration range. The decrease was most pronounced between 25 and 250 μM K. In a subsequent experiment, lettuce was grown for 20 days under the same climatic conditions in two sandy-foam soils (A, B) contaminated with 134 Cs. Both had similar characteristics but differed widely in K supply. Soil solution K concentrations were 100 μM (A) or 3000 μM (B). The radiocesium soil-to-plant Transfer Factor (TF, g plant dry weight / g soil) was 0.320 in soil A and 0.016 in soil B. The higher 137 Cs availability at the lower K supply (soil A) was contrasted by lower 137 Cs concentrations in soil solution of soil A than of soil B. Radiocesium transfer to lettuce grown to maturity was analysed on 5 different lysimeter soils under controlled climatic conditions. The soils were artificially contaminated with 137 Cs in 1994. The TF's varied between 0.032 and 0.191 and were not related to K concentrations in soil solution. The CF decreased about 100-fold with K concentrations increasing from 0.3 to 18 mM. Predictions of soil-to-plant transfer factors based on soil solution composition and nutrient solution results were qualitatively correct but underestimated the observed values

  19. Contribution of the ''simple solutions'' concept to estimate density of actinides concentrated solutions

    International Nuclear Information System (INIS)

    Sorel, C.; Moisy, Ph.; Dinh, B.; Blanc, P.

    2000-01-01

    In order to calculate criticality parameters of nuclear fuel solution systems, number density of nuclides are needed and they are generally estimated from density equations. Most of the relations allowing the calculation of the density of aqueous solutions containing the electrolytes HNO 3 -UO 2 (NO 3 ) 2 -Pu(NO 3 ) 4 , usually called 'nitrate dilution laws' are strictly empirical. They are obtained from a fit of assumed polynomial expressions on experimental density data. Out of their interpolation range, such mathematical expressions show discrepancies between calculated and experimental data appearing in the high concentrations range. In this study, a physico-chemical approach based on the isopiestic mixtures rule is suggested. The behaviour followed by these mixtures was first observed in 1936 by Zdanovskii and expressed as: 'Binary solutions (i.e. one electrolyte in water) having a same water activity are mixed without variation of this water activity value'. With regards to this behaviour, a set of basic thermodynamic expressions has been pointed out by Ryazanov and Vdovenko in 1965 concerning enthalpy, entropy, volume of mixtures, activity and osmotic coefficient of the components. In particular, a very simple relation for the density is obtained from the volume mixture expression depending on only two physico-chemical variables: i) concentration of each component in the mixture and in their respectively binary solutions having the same water activity as the mixture and ii), density of each component respectively in the binary solution having the same water activity as the mixture. Therefore, the calculation needs the knowledge of binary data (water activity, density and concentration) of each component at the same temperature as the mixture. Such experimental data are largely published in the literature and are available for nitric acid and uranyl nitrate. Nevertheless, nitric acid binary data show large discrepancies between the authors and need to be

  20. [Effect of microbial nutrient concentration on improvement of municipal sewage sludge dewaterability through bioleaching].

    Science.gov (United States)

    Song, Yong-wei; Liu, Fen-wu; Zhou, Li-xiang

    2012-08-01

    In this study, shaking flask batch experiments and practical engineering application tests were performed to investigate the effect of microbial nutrient concentration on the dewaterability of municipal sewage sludge with 2%, 3%, 4% and 5% solid contents via bioleaching. Meanwhile, the changes of pH value and the utilization efficiency of microbial nutrients during bioleaching were analyzed in this study. The results showed that the pH value decreased gradually at the beginning and then maintained a stable state in the treatments with different solid contents, and the nutrients were completely used up by the microorganisms after 2 days of bioleaching. It was found that the SRF of 2%, 3%, 4%, 5% sludges decreased quickly and then rose gradually with the extension of bioleaching time. In addition, the higher solid content the greater the increase. It was determined that the optimum microbial nutrient dosage for sludge with solid content of 2%, 3%, 4% and 5% were 3.0 g x L(-1), 4.5 g x L(-1), 8.3 g x L(-1) and 12.8 g x L(-1) respectively. At this point, the lowest SRF of sludge with each solid content were 0.61 x 10(12) m x kg(-1), 1.22 x 10(12) m x kg(-1), 3.09 x 10(12) m x kg(-1) and 4.83 x 10(12) m x kg(-1), respectively. Through the engineering application, it was showed that diluting the solid content of sewage sludge from 5% to 3% before bioleaching was feasible. It could not only improve the dewaterability of bioleached sewage sludge (the SRF declined from 3.29 x 10(12) m x kg(-1) to 1.10 x 10(12) m x kg(-1)), but also shorten the sludge nutrient time (shortened from 4 days to 2.35 days) and reduce the operation costs. Therefore, the results of this study have important significance for the engineering application of bioleaching of municipal sewage sludge with high solid content.

  1. Effects of elevated CO2 concentration on growth and water usage of tomato seedlings under different ammonium/nitrate ratios

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Increasing atmospheric CO2 concentration is generally expected to enhance photosynthesis and growth of agricultural C3 vegetable crops,and therefore results in an increase in crop yield.However,little is known about the combined effect of elevated CO2 and N species on plant growth and development.Two growth-chamber experiments were conducted to determine the effects of NH4+/NO3- ratio and elevated CO2 concentration on the physiological development and water use of tomato seedlings.Tomato was grown for 45 d in containers with nutrient solutions varying in NH4+/NO3- ratios and CO2 concentrations in growth chambers.Results showed that plant height,stem thickness,total dry weight,dry weight of the leaves,stems and roots,G value (total plant dry weight/seedling days),chlorophyll content,photosynthetic rate,leaf-level and whole plant-level water use efficiency and cumulative water consumption of tomato seedlings were increased with increasing proportion of NO3- in nutrient solutions in the elevated CO2 treatment.Plant biomass,plant height,stem thickness and photosynthetic rate were 67%,22%,24% and 55% higher at elevated CO2 concentration than at ambient CO2 concentration,depending on the values of NH4+/NO3- ratio.These results indicated that elevating CO2 concentration did not mitigate the adverse effects of 100% NH4+-N (in nutrient solution) on the tomato seedlings.At both CO2 levels,NH4+/NO3- ratios of nutrient solutions strongly influenced almost every measure of plant performance,and nitrate-fed plants attained a greater biomass production,as compared to ammonium-fed plants.These phenomena seem to be related to the coordinated regulation of photosynthetic rate and cumulative water consumption of tomato seedlings.

  2. How to know which food is good for you: bumblebees use taste to discriminate between different concentrations of food differing in nutrient content.

    Science.gov (United States)

    Ruedenauer, Fabian A; Spaethe, Johannes; Leonhardt, Sara D

    2015-07-01

    In view of the ongoing pollinator decline, the role of nutrition in bee health has received increasing attention. Bees obtain fat, carbohydrates and protein from pollen and nectar. As both excessive and deficient amounts of these macronutrients are detrimental, bees would benefit from assessing food quality to guarantee an optimal nutrient supply. While bees can detect sucrose and use it to assess nectar quality, it is unknown whether they can assess the macronutrient content of pollen. Previous studies have shown that bees preferentially collect pollen of higher protein content, suggesting that differences in pollen quality can be detected either by individual bees or via feedback from larvae. In this study, we examined whether and, if so, how individuals of the buff-tailed bumblebee (Bombus terrestris) discriminate between different concentrations of pollen and casein mixtures and thus nutrients. Bumblebees were trained using absolute and differential conditioning of the proboscis extension response (PER). As cues related to nutrient concentration could theoretically be perceived by either smell or taste, bees were tested on both olfactory and, for the first time, chemotactile perception. Using olfactory cues, bumblebees learned and discriminated between different pollen types and casein, but were unable to discriminate between different concentrations of these substances. However, when they touched the substances with their antennae, using chemotactile cues, they could also discriminate between different concentrations. Bumblebees are therefore able to discriminate between foods of different concentrations using contact chemosensory perception (taste). This ability may enable them to individually regulate the nutrient intake of their colonies. © 2015. Published by The Company of Biologists Ltd.

  3. Opalescence in monoclonal antibody solutions and its correlation with intermolecular interactions in dilute and concentrated solutions.

    Science.gov (United States)

    Raut, Ashlesha S; Kalonia, Devendra S

    2015-04-01

    Opalescence indicates physical instability of a formulation because of the presence of aggregates or liquid-liquid phase separation in solution and has been reported for monoclonal antibody (mAb) formulations. Increased solution opalescence can be attributed to attractive protein-protein interactions (PPIs). Techniques including light scattering, AUC, or membrane osmometry are routinely employed to measure PPIs in dilute solutions, whereas opalescence is seen at relatively higher concentrations, where both long- and short-range forces contribute to overall PPIs. The mAb molecule studied here shows a unique property of high opalescence because of liquid-liquid phase separation. In this study, opalescence measurements are correlated to PPIs measured in diluted and concentrated solutions using light scattering (kD ) and high-frequency rheology (G'), respectively. Charges on the molecules were calculated using zeta potential measurements. Results indicate that high opalescence and phase separation are a result of the attractive interactions in solution; however, the presence of attractive interactions do not always imply phase separation. Temperature dependence of opalescence suggests that thermodynamic contribution to opalescence is significant and Tcloud can be utilized as a potential tool to assess attractive interactions in solution. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  4. Effect of wood ash application on soil solution chemistry of tropical acid soils: incubation study.

    Science.gov (United States)

    Nkana, J C Voundi; Demeyer, A; Verloo, M G

    2002-12-01

    The objective of this study was to determine the effect of wood ash application on soil solution composition of three tropical acid soils. Calcium carbonate was used as a reference amendment. Amended soils and control were incubated for 60 days. To assess soluble nutrients, saturation extracts were analysed at 15 days intervals. Wood ash application affects the soil solution chemistry in two ways, as a liming agent and as a supplier of nutrients. As a liming agent, wood ash application induced increases in soil solution pH, Ca, Mg, inorganic C, SO4 and DOC. As a supplier of elements, the increase in the soil solution pH was partly due to ligand exchange between wood ash SO4 and OH- ions. Large increases in concentrations of inorganic C, SO4, Ca and Mg with wood ash relative to lime and especially increases in K reflected the supply of these elements by wood ash. Wood ash application could represent increased availability of nutrients for the plant. However, large concentrations of basic cations, SO4 and NO3 obtained with higher application rates could be a concern because of potential solute transport to surface waters and groundwater. Wood ash must be applied at reasonable rates to avoid any risk for the environment.

  5. Use of ultraviolet-disinfected nutrient solutions in greenhouses

    International Nuclear Information System (INIS)

    Acher, A.; Heuer, B.; Rubinskaya, E.; Fischer, E.

    1997-01-01

    Environmental concerns and economics require the recycling of plant nutrient solutions (PNS) used in soilless cultures in greenhouses. To avoid possible outbreaks of plant diseases, disinfection of the recycled PNS might be necessary. This paper describes a case study on the stability of Fe 3+ -chelates, present in PNS and exposed to ultraviolet radiation (UV 254 nm) for disinfection, and the effect on plant growth. Three Fe-chelates, each containing 2 mg Fe 3+ l -1 , in PNS were: i, Fe-EDDHA (Fe-ethylene-diamine-dihydroxyphenyl acetic acid); ii, Fe-Na-EDTA (Fe-ethylene-diamine-tetraacetic acid); and iii, Fe-DTPA (Fe-diethylene-triamine-pentaacetic acid). Seedlings of sorghum, corn and tomatoes were grown hydroponically for four weeks in continuously aerated PNS, which had been exposed previously for 0, 2.5 and 130 s to a UV radiation fluence of 80 mW s -1 cm -2 . The accumulation of plant fresh weight (APFW) differed from non-treated controls, depending on chelating agent and on exposure time to UV. The greatest APFW was observed in sorghum (128, 178 and 98%) at 2.5 s UV-exposure for PNS containing i, ii and iii, respectively. For corn and tomato, the respective results were: 108, 139 and 96%, and 129, 91 and 89% for tomatoes, respectively. The stability of i, ii and iii upon exposure to UV radiation is discussed. (author)

  6. A new method to measure effective soil solution concentration predicts copper availability to plants.

    Science.gov (United States)

    Zhang, H; Zhao, F J; Sun, B; Davison, W; McGrath, S P

    2001-06-15

    Risk assessments of metal contaminated soils need to address metal bioavailability. To predict the bioavailability of metals to plants, it is necessary to understand both solution and solid phase supply processes in soils. In striving to find surrogate chemical measurements, scientists have focused either on soil solution chemistry, including free ion activities, or operationally defined fractions of metals. Here we introduce the new concept of effective concentration, CE, which includes both the soil solution concentration and an additional term, expressed as a concentration, that represents metal supplied from the solid phase. CE was measured using the technique of diffusive gradients in thin films (DGT) which, like a plant, locally lowers soil solution concentrations, inducing metal supply from the solid phase, as shown by a dynamic model of the DGT-soil system. Measurements of Cu as CE, soil solution concentration, by EDTA extraction and as free Cu2+ activity in soil solution were made on 29 different soils covering a large range of copper concentrations. Theywere compared to Cu concentrations in the plant material of Lepidium heterophyllum grown on the same soils. Plant concentrations were linearly related and highly correlated with CE but were more scattered and nonlinear with respect to free Cu2+ activity, EDTA extraction, or soil solution concentrations. These results demonstrate that the dominant supply processes in these soils are diffusion and labile metal release, which the DGT-soil system mimics. The quantity CE is shown to have promise as a quantitative measure of the bioavailable metal in soils.

  7. Ammonia complexes of metals in aqueous solutions with high concentrations of ammonia

    International Nuclear Information System (INIS)

    Padar, T.G.; Novikov, L.K.; Stupko, T.V.; Isaev, I.D.; Pashkov, G.L.; Mironov, V.E.

    1991-01-01

    Potentiometric method, glass electrodes and Bierrum function were used to study the formation of ammonia complexes of magnesium, calcium, cadmium, zinc, copper(2) and silver in 2.0 mol/dm 3 aqueous solutions of ammonia nitrate with 0-18 mol/dm 3 ammonia concentrations at 25.0 deg C. Step constants of stability of studied complexes were calculated and their compositions were determined with account of nonideal character of aqueous-salt solutions with ammonia concentrations above 1.0 mol/dm 3 . Values of correction effects on salting out ammonia action for Bierrum function in solutions with 1.0-18 mol/dm 3 ammonia concentrations were found

  8. A NOVEL INTERPRETATION OF CONCENTRATION DEPENDENCE OF VISCOSITY OF DILUTE POLYMER SOLUTION

    Institute of Scientific and Technical Information of China (English)

    Yan Pan; Rong-shi Cheng

    2000-01-01

    The concentration dependence of the reduced viscosity of dilute polymer solution is interpreted in the light of a new concept of the self-association of polymer chains in dilute solution. The apparent self-association constant is defined as the molar association constant divided by the molar mass of individual polymer chain and is numerically interconvertible with the Huggins coefficient. The molar association constant is directly proportional to the effective hydrodynamic volume of the polymer chain in solution and is irrespective of the chain architecture. The effective hydrodynamic volume accounts for the non-spherical conformation of a short polymer chain in solution and is a product of a shape factor and hydrodynamic volume. The observed enhancement of Huggins coefficient for short chain and branched polymer is satisfactorily interpreted by the concept of self-association. The concept of self-association allows us to predict the existence of a boundary concentration Cs (dynamic contact concentration) which divides the dilute polymer solution into two regions.

  9. Proximate and ultimate controls on carbon and nutrient dynamics of small agricultural catchments

    Science.gov (United States)

    Thomas, Zahra; Abbott, Benjamin W.; Troccaz, Olivier; Baudry, Jacques; Pinay, Gilles

    2016-03-01

    Direct and indirect effects from human activity have dramatically increased nutrient loading to aquatic inland and estuarine ecosystems. Despite an abundance of studies investigating the impact of agricultural activity on water quality, our understanding of what determines the capacity of a watershed to remove or retain nutrients remains limited. The goal of this study was to identify proximate and ultimate controls on dissolved organic carbon and nutrient dynamics in small agricultural catchments by investigating the relationship between catchment characteristics, stream discharge, and water chemistry. We analyzed a 5-year, high-frequency water chemistry data set from three catchments in western France ranging from 2.3 to 10.8 km2. The relationship between hydrology and solute concentrations differed between the three catchments and was associated with hedgerow density, agricultural activity, and geology. The catchment with thicker soil and higher surface roughness had relatively invariant carbon and nutrient chemistry across hydrologic conditions, indicating high resilience to human disturbance. Conversely, the catchments with smoother, thinner soils responded to both intra- and interannual hydrologic variation with high concentrations of phosphate (PO43-) and ammonium (NH4+) in streams during low flow conditions and strong increases in dissolved organic carbon (DOC), sediment, and particulate organic matter during high flows. Despite contrasting agricultural activity between catchments, the physical context (geology, topography, and land-use configuration) appeared to be the most important determinant of catchment solute dynamics based on principle components analysis. The influence of geology and accompanying topographic and geomorphological factors on water quality was both direct and indirect because the distribution of agricultural activity in these catchments is largely a consequence of the geologic and topographic context. This link between inherent

  10. Nitrogen concentration in dry matter of the fifth leaf during growth of greenhouse tomato plants

    Directory of Open Access Journals (Sweden)

    Rattin Jorge E.

    2002-01-01

    Full Text Available The nitrogen concentration in dry matter of the fifth leaf during growth of a greenhouse tomato crop was determined. Plants of hybrid Monte Carlo were grown in 4.5 L bags, using a commercial substrate, in a plant density of 3.3 plants m-2. A nutrient solution containing, in mmol L-1: KNO3, 4.0; K2SO4, 0.9; Ca(NO32, 3.75; KH2PO4, 1.5; MgSO4, 1.0; iron chelate 19. 10³, was used as reference. Microelements were added by a commercial mixture. The T3 treatment was equal to the reference nutrient solution, whereas in treatments T1, T2, T4 and T5 quantities of all nutrients from T3 were multiplied by 0.25, 0.50, 1.25 and 1.50, respectively. In each treatment, the volume of 1 L of nutrient solution was supplied to each plant once a week by fertigation. Periodically destructive measurements were made from anthesis to ripening of the first truss, to determine dry matter and N concentration in shoot and in fifth leaf tissues, counted from the apex to the bottom of the plant. Five dilution curves were fitted from data of N concentration in the fifth leaf and shoot dry matter accumulation during growth of plants. A general relationship was adjusted between actual N concentration in shoot (Nt and in the fifth leaf (Nf: Nt = 1.287 Nf (R² = 0.80. This relationship could be used to estimate the N status of plants by means of a nitrogen nutrition index (NNI, from analysis of the fifth leaf sap.

  11. Densities concentrations of aqueous of uranyl nitrate solutions

    International Nuclear Information System (INIS)

    Rodrigo Otero, A.; Rodriguez Hernandez, B.; Fernandez Rodriguez, L.

    1966-01-01

    The ratio density-concentration of aqueous uranyl nitrate solutions expressed as U 3 O 8 grams/liter, U grams/liter and hexahydrate uranyl nitrate weight percent at different temperatures, are established. Experimental values are graphically correlated and compared whit some published data. (Author) 2 refs

  12. A dynamic growth model of vegetative soya bean plants: model structure and behaviour under varying root temperature and nitrogen concentration

    Science.gov (United States)

    Lim, J. T.; Wilkerson, G. G.; Raper, C. D. Jr; Gold, H. J.

    1990-01-01

    A differential equation model of vegetative growth of the soya bean plant (Glycine max (L.) Merrill cv. Ransom') was developed to account for plant growth in a phytotron system under variation of root temperature and nitrogen concentration in nutrient solution. The model was tested by comparing model outputs with data from four different experiments. Model predictions agreed fairly well with measured plant performance over a wide range of root temperatures and over a range of nitrogen concentrations in nutrient solution between 0.5 and 10.0 mmol NO3- in the phytotron environment. Sensitivity analyses revealed that the model was most sensitive to changes in parameters relating to carbohydrate concentration in the plant and nitrogen uptake rate.

  13. Response of dissolved carbon and nitrogen concentrations to moderate nutrient additions in a tropical montane forest of south Ecuador

    Science.gov (United States)

    Velescu, Andre; Valarezo, Carlos; Wilcke, Wolfgang

    2016-05-01

    In the past two decades, the tropical montane rain forests in south Ecuador experienced increasing deposition of reactive nitrogen mainly originating from Amazonian forest fires, while Saharan dust inputs episodically increased deposition of base metals. Increasing air temperature and unevenly distributed rainfall have allowed for longer dry spells in a perhumid ecosystem. This might have favored mineralization of dissolved organic matter (DOM) by microorganisms and increased nutrient release from the organic layer. Environmental change is expected to impact the functioning of this ecosystem belonging to the biodiversity hotspots of the Earth. In 2007, we established a nutrient manipulation experiment (NUMEX) to understand the response of the ecosystem to moderately increased nutrient inputs. Since 2008, we have continuously applied 50 kg ha-1 a-1 of nitrogen (N), 10 kg ha-1 a-1 of phosphorus (P), 50 kg + 10 kg ha-1 a-1 of N and P and 10 kg ha-1 a-1 of calcium (Ca) in a randomized block design at 2000 m a.s.l. in a natural forest on the Amazonia-exposed slopes of the south Ecuadorian Andes. Nitrogen concentrations in throughfall increased following N+P additions, while separate N amendments only increased nitrate concentrations. Total organic carbon (TOC) and dissolved organic nitrogen (DON) concentrations showed high seasonal variations in litter leachate and decreased significantly in the P and N+P treatments, but not in the N treatment. Thus, P availability plays a key role in the mineralization of DOM. TOC/DON ratios were narrower in throughfall than in litter leachate but their temporal course did not respond to nutrient amendments. Our results revealed an initially fast, positive response of the C and N cycling to nutrient additions which declined with time. TOC and DON cycling only change if N and P supply are improved concurrently, while NO3-N leaching increases only if N is separately added. This indicates co-limitation of the microorganisms by N and P

  14. Response of dissolved carbon and nitrogen concentrations to moderate nutrient additions in a tropical montane forest of south Ecuador

    Directory of Open Access Journals (Sweden)

    Andre eVelescu

    2016-05-01

    Full Text Available In the past two decades, the tropical montane rain forests in south Ecuador experienced increasing deposition of reactive nitrogen mainly originating from Amazonian forest fires, while Saharan dust inputs episodically increased deposition of base metals. Increasing air temperature and unevenly distributed rainfall have allowed for longer dry spells in a perhumid ecosystem. This might have favored mineralization of dissolved organic matter (DOM by microorganisms and increased nutrient release from the organic layer. Environmental change is expected to impact the functioning of this ecosystem belonging to the biodiversity hotspots of the Earth.In 2007, we established a nutrient manipulation experiment (NUMEX to understand the response of the ecosystem to moderately increased nutrient inputs. Since 2008, we have continuously applied 50 kg ha-1 a-1 of nitrogen (N, 10 kg ha-1 a-1 of phosphorus (P, 50 kg + 10 kg ha-1 a-1 of N and P and 10 kg ha-1 a-1 of calcium (Ca in a randomized block design at 2000 m a.s.l. in a natural forest on the Amazonia-exposed slopes of the south Ecuadorian Andes.Nitrogen concentrations in throughfall increased following N+P additions, while separate N amendments only increased nitrate concentrations. Total organic carbon (TOC and dissolved organic nitrogen (DON concentrations showed high seasonal variations in litter leachate and decreased significantly in the P and N+P treatments, but not in the N treatment. Thus, P availability plays a key role in the mineralization of DOM. TOC/DON ratios were narrower in throughfall than in litter leachate but their temporal course did not respond to nutrient amendments.Our results revealed an initially fast, positive response of the C and N cycling to nutrient additions which declined with time. TOC and DON cycling only change if N and P supply are improved concurrently, while NO3-N leaching increases only if N is separately added. This indicates co-limitation of the microorganisms by N

  15. Methods of preparing and using intravenous nutrient compositions

    International Nuclear Information System (INIS)

    Beigler, M.A.; Koury, A.J.

    1983-01-01

    A method for preparing a stable, dry-packaged, sterile, nutrient composition which upon addition of sterile, pyrogen-free water is suitable for intravenous administration to a mammal, including a human, is described. The method comprises providing the nutrients in a specific dry form and state of physical purity acceptable for intravenous administration, sealing the nutrients in a particular type of container adapted to receive and dispense sterile fluids and subjecting the container and its sealed contents to a sterilizing, nondestructive dose of ionizing radiation. The method results in a packaged, sterile nutrient composition which may be dissolved by the addition of sterile pyrogen-free water. The resulting aqueous intravenous solution may be safely administered to a mammal in need of nutrient therapy. The packaged nutrient compositions of the invention exhibit greatly extended storage life and provide an economical method of providing intravenous solutions which are safe and efficacious for use. (author)

  16. Nutrição mineral, crescimento e teor de óleo essencial da menta em solução nutritiva sob diferentes concentrações de fósforo e épocas de coleta Mineral nutrition, growth and essential oil content of mint in nutrient solution under different phosphorus concentrations

    Directory of Open Access Journals (Sweden)

    Carlos R. Rodrigues

    2004-09-01

    content of mint (Mentha piperita L. was evaluated. The experimental design was of randomized blocks in a split-plot scheme, in a 2x5 factorial with four replications, being two harvest periods (65 and 95 days of cultivation (DC and five concentrations of P in the nutrient solution (6; 12; 18; 24 and 30 mg L-1 evaluated. The leaves dry weight (MSF, stems dry weight (MRS, roots dry weight (MSR, total dry weight (MST, leaf:stem ratio (F:C and aerial part:root ratio (PA:R were evaluated. The essential oil content in fresh leaves was determined. The critical levels and nutrient accumulation in leaves and stems were estimated through leaves and stems chemical analysis. The level of P increased the leaf dry matter production 65 DC. At 95 DC, the P concentration in the nutrient solution, did significantly increase plant growth and essential oil content, the maximum essential oil content being (2.192 dag kg-1 obtained with 19.48 mg L-1 of P. The higher P concentration in nutrient solution (24 and 30 mg L-1, increased the fresh and dry matter of the aerial portion of the plants, but, decreased the essential oil content. Due to the dilution effect, the increase of fresh and dry matter production did not result in an increase in the oil yield per plant. The critical levels of nutrients in the leaves corresponding to the maximum essential oil content at 95 DC in g kg-1 were: N=37,2; P=3,9; K=21,2; Ca=9,3; Mg=3,8; S=3,0 and, in mg kg-1: B=35; Cu=8; Fe=323; Mn=145 and Zn=22. The nutrients requested at 95 DC related to the maximum essential oil content was: N>K>Ca>P>Mg>S>Fe>Mn>B>Zn>Cu.

  17. Impact of solute concentration on the electrocatalytic conversion of dissolved gases in buffered solutions

    KAUST Repository

    Shinagawa, Tatsuya; Takanabe, Kazuhiro

    2015-01-01

    . These alterations of the electrolyte properties associated with the solute concentration are universally applicable to other aqueous gas-related electrochemical reactions because the currents are purely determined by mass transfer of the dissolved gases. © 2015

  18. Conductivity and electrochemical stability of concentrated aqueous choline chloride solutions

    Science.gov (United States)

    Grishina, E. P.; Kudryakova, N. O.

    2017-10-01

    The conductivity and electrochemical stability of choline chloride (ChCl) solutions with water contents ranging from 20 to 39 wt % are studied. Exposing ChCl to moist ambient air yields a highly concentrated aqueous solution that, as an electrolyte, exhibits the properties and variations in conductivity with temperature and concentration characteristic of other similar systems. Its electrochemical stability window, determined by cyclic voltammetry, is comparable to that of ChCl-based deep eutectic solvents (DESs). Products of the electrolysis of ChCl‒H2O mixtures seem to be less toxic than those of Reline, Ethaline, and Maline.

  19. Agronomic potential of mineral concentrate from processed manure as fertiliser

    NARCIS (Netherlands)

    Velthof, G.L.; Hoeksma, P.; Schröder, J.J.; Middelkoop, van J.C.; Geel, van W.C.A.; Ehlert, P.A.I.; Holshof, G.; Klop, G.; Lesschen, J.P.

    2012-01-01

    Processing of manure intends to increase the use efficiency of nutrients. A concentrated solution of nitrogen (N) and potassium (K) (‘mineral concentrate’) is one of the possible products resulting from manure processing. A study is carried out in the Netherlands to determine the agronomic and

  20. Micro and Macroscale Drivers of Nutrient Concentrations in Urban Streams in South, Central and North America.

    Science.gov (United States)

    Loiselle, Steven A; Gasparini Fernandes Cunha, Davi; Shupe, Scott; Valiente, Elsa; Rocha, Luciana; Heasley, Eleanore; Belmont, Patricia Pérez; Baruch, Avinoam

    Global metrics of land cover and land use provide a fundamental basis to examine the spatial variability of human-induced impacts on freshwater ecosystems. However, microscale processes and site specific conditions related to bank vegetation, pollution sources, adjacent land use and water uses can have important influences on ecosystem conditions, in particular in smaller tributary rivers. Compared to larger order rivers, these low-order streams and rivers are more numerous, yet often under-monitored. The present study explored the relationship of nutrient concentrations in 150 streams in 57 hydrological basins in South, Central and North America (Buenos Aires, Curitiba, São Paulo, Rio de Janeiro, Mexico City and Vancouver) with macroscale information available from global datasets and microscale data acquired by trained citizen scientists. Average sub-basin phosphate (P-PO4) concentrations were found to be well correlated with sub-basin attributes on both macro and microscales, while the relationships between sub-basin attributes and nitrate (N-NO3) concentrations were limited. A phosphate threshold for eutrophic conditions (>0.1 mg L-1 P-PO4) was exceeded in basins where microscale point source discharge points (eg. residential, industrial, urban/road) were identified in more than 86% of stream reaches monitored by citizen scientists. The presence of bankside vegetation covaried (rho = -0.53) with lower phosphate concentrations in the ecosystems studied. Macroscale information on nutrient loading allowed for a strong separation between basins with and without eutrophic conditions. Most importantly, the combination of macroscale and microscale information acquired increased our ability to explain sub-basin variability of P-PO4 concentrations. The identification of microscale point sources and bank vegetation conditions by citizen scientists provided important information that local authorities could use to improve their management of lower order river ecosystems.

  1. The use of erbium fiber laser relaxation frequency for sensing refractive index and solute concentration of aqueous solutions

    International Nuclear Information System (INIS)

    Arellano-Sotelo, H; Barmenkov, Yu O; Kir'yanov, A V

    2008-01-01

    We report a novel-principle fiber-laser intra-cavity sensor for measuring refractive index and solute concentration of aqueous solutions. The sensor operation is based on a variation of the laser oscillation relaxation frequency (the measured parameter), sensitive to the intra-cavity loss change. The sensor capacity is demonstrated on the example of measurements of sugar concentration in water. A modeling of the sensor operation is presented, allowing its performance optimization

  2. Stability and Concentration Verification of Ammonium Perchlorate Dosing Solutions

    National Research Council Canada - National Science Library

    Tsui, David

    1998-01-01

    Stability and concentration verification was performed for the ammonium perchlorate dosing solutions used in the on-going 90-Day Oral Toxicity Study conducted by Springborn Laboratories, Inc. (SLI Study No. 3433.1...

  3. Removal of 4-chlorobenzoic acid from spiked hydroponic solution by willow trees (Salix viminalis)

    DEFF Research Database (Denmark)

    Deavers, K.; Macek, T.; Karlson, U.

    2010-01-01

    . Methods The removal of 4-CBA by willow trees was investigated with intact, septic willow trees growing in hydroponic solution and with sterile cell suspensions at concentrations of 5 mg/L and 50 mg/L 4-CBA. Nutrient solutions with different levels of ammonium and nitrate were prepared to achieve different...

  4. Passivation behavior of a ferritic stainless steel in concentrated alkaline solutions

    Directory of Open Access Journals (Sweden)

    Arash Fattah-alhosseini

    2015-10-01

    Full Text Available The passivation behavior of AISI 430 ferritic stainless steel was investigated in concentrated alkaline solutions in relation to several test parameters, using electrochemical techniques. Increasing solution pH (varying from 11.5 to 14.0 leads to an increase in the corrosion rate of the alloy. Mott–Schottky analysis revealed that passive films formed on AISI 430 ferritic stainless steel behave as n-type semiconductor and the donor densities increased with pH. Electrochemical impedance spectroscopy (EIS results showed that the reciprocal capacitance of the passive film is directly proportional to its thickness, which decreases with pH increase. The results revealed that for this ferritic stainless steel in concentrated alkaline solutions, decreasing the solution pH offers better conditions for forming passive films with higher protection behavior, due to the growth of a much thicker and less defective film.

  5. Acquisition and Analysis of Data from High Concentration Solutions

    KAUST Repository

    Besong, Tabot M.D.

    2016-05-13

    The problems associated with ultracentrifugal analysis of macromolecular solutions at high (>10 mg/ml) are reviewed. Especially for the case of solutes which are non-monodisperse, meaningful results are not readily achievable using sedimentation velocity approaches. It is shown however by both simulation and analysis of practical data that using a modified form of an algorithm (INVEQ) published in other contexts, sedimentation equilibrium (SE) profiles can be analysed successfully, enabling topics such as oligomer presence or formation to be defined.To achieve this, it is necessary to employ an approach in which the solution density, which in an SE profile is radius-dependent, is taken into consideration. Simulation suggests that any reasonable level of solute concentration can be analysed.

  6. Acquisition and Analysis of Data from High Concentration Solutions

    KAUST Repository

    Besong, Tabot M.D.; Rowe, Arthur J.

    2016-01-01

    The problems associated with ultracentrifugal analysis of macromolecular solutions at high (>10 mg/ml) are reviewed. Especially for the case of solutes which are non-monodisperse, meaningful results are not readily achievable using sedimentation velocity approaches. It is shown however by both simulation and analysis of practical data that using a modified form of an algorithm (INVEQ) published in other contexts, sedimentation equilibrium (SE) profiles can be analysed successfully, enabling topics such as oligomer presence or formation to be defined.To achieve this, it is necessary to employ an approach in which the solution density, which in an SE profile is radius-dependent, is taken into consideration. Simulation suggests that any reasonable level of solute concentration can be analysed.

  7. An isotherm-based thermodynamic model of multicomponent aqueous solutions, applicable over the entire concentration range.

    Science.gov (United States)

    Dutcher, Cari S; Ge, Xinlei; Wexler, Anthony S; Clegg, Simon L

    2013-04-18

    In previous studies (Dutcher et al. J. Phys. Chem. C 2011, 115, 16474-16487; 2012, 116, 1850-1864), we derived equations for the Gibbs energy, solvent and solute activities, and solute concentrations in multicomponent liquid mixtures, based upon expressions for adsorption isotherms that include arbitrary numbers of hydration layers on each solute. In this work, the long-range electrostatic interactions that dominate in dilute solutions are added to the Gibbs energy expression, thus extending the range of concentrations for which the model can be used from pure liquid solute(s) to infinite dilution in the solvent, water. An equation for the conversion of the reference state for solute activity coefficients to infinite dilution in water has been derived. A number of simplifications are identified, notably the equivalence of the sorption site parameters r and the stoichiometric coefficients of the solutes, resulting in a reduction in the number of model parameters. Solute concentrations in mixtures conform to a modified Zdanovskii-Stokes-Robinson mixing rule, and solute activity coefficients to a modified McKay-Perring relation, when the effects of the long-range (Debye-Hückel) term in the equations are taken into account. Practical applications of the equations to osmotic and activity coefficients of pure aqueous electrolyte solutions and mixtures show both satisfactory accuracy from low to high concentrations, together with a thermodynamically reasonable extrapolation (beyond the range of measurements) to extreme concentration and to the pure liquid solute(s).

  8. A dual porosity model of nutrient uptake by root hairs

    KAUST Repository

    Zygalakis, K. C.; Kirk, G. J. D.; Jones, D. L.; Wissuwa, M.; Roose, T.

    2011-01-01

    Summary: • The importance of root hairs in the uptake of sparingly soluble nutrients is understood qualitatively, but not quantitatively, and this limits efforts to breed plants tolerant of nutrient-deficient soils. • Here, we develop a mathematical model of nutrient uptake by root hairs allowing for hair geometry and the details of nutrient transport through soil, including diffusion within and between soil particles. We give illustrative results for phosphate uptake. • Compared with conventional 'single porosity' models, this 'dual porosity' model predicts greater root uptake because more nutrient is available by slow release from within soil particles. Also the effect of soil moisture is less important with the dual porosity model because the effective volume available for diffusion in the soil is larger, and the predicted effects of hair length and density are different. • Consistent with experimental observations, with the dual porosity model, increases in hair length give greater increases in uptake than increases in hair density per unit main root length. The effect of hair density is less in dry soil because the minimum concentration in solution for net influx is reached more rapidly. The effect of hair length is much less sensitive to soil moisture. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  9. A dual porosity model of nutrient uptake by root hairs

    KAUST Repository

    Zygalakis, K. C.

    2011-08-09

    Summary: • The importance of root hairs in the uptake of sparingly soluble nutrients is understood qualitatively, but not quantitatively, and this limits efforts to breed plants tolerant of nutrient-deficient soils. • Here, we develop a mathematical model of nutrient uptake by root hairs allowing for hair geometry and the details of nutrient transport through soil, including diffusion within and between soil particles. We give illustrative results for phosphate uptake. • Compared with conventional \\'single porosity\\' models, this \\'dual porosity\\' model predicts greater root uptake because more nutrient is available by slow release from within soil particles. Also the effect of soil moisture is less important with the dual porosity model because the effective volume available for diffusion in the soil is larger, and the predicted effects of hair length and density are different. • Consistent with experimental observations, with the dual porosity model, increases in hair length give greater increases in uptake than increases in hair density per unit main root length. The effect of hair density is less in dry soil because the minimum concentration in solution for net influx is reached more rapidly. The effect of hair length is much less sensitive to soil moisture. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  10. Small angle X-ray scattering on concentrated hemoglobin solutions

    International Nuclear Information System (INIS)

    Zinke, M.; Damaschun, G.; Mueller, J.J.; Ruckpaul, K.

    1978-01-01

    The small-angle X-ray scattering technique was used to determine the intermolecular structure and interaction potentials in oxi-and deoxi-hemoglobin solutions. The pair correlation function obtained by the ZERNICKE-PRINS equation characterizes the intermolecular structure of the hemoglobin molecules. The intermolecular structure is concentration dependent. The hemoglobin molecules have a 'short range order structure' with a range of about 4 molecule diameters at 324 g/l. The potential functions of the hemoglobin-hemoglobin interaction have been determined on the basis of fluid theories. Except for the deoxi-hemoglobin solution having the concentration 370 g/l, the pair interaction consists in a short repulsion and a weak short-range attraction against kT. The potential minimum is between 1.2 - 1.5 nm above the greatest hemoglobin diameter. (author)

  11. Plant response to nutrient availability across variable bedrock geologies

    Science.gov (United States)

    Castle, S.C.; Neff, J.C.

    2009-01-01

    We investigated the role of rock-derived mineral nutrient availability on the nutrient dynamics of overlying forest communities (Populus tremuloides and Picea engelmanni-Abies lasiocarpa v. arizonica) across three parent materials (andesite, limestone, and sandstone) in the southern Rocky Mountains of Colorado. Broad geochemical differences were observed between bedrock materials; however, bulk soil chemistries were remarkably similar between the three different sites. In contrast, soil nutrient pools were considerably different, particularly for P, Ca, and Mg concentrations. Despite variations in nutrient stocks and nutrient availability in soils, we observed relatively inflexible foliar concentrations and foliar stoichiometries for both deciduous and coniferous species. Foliar nutrient resorption (P and K) in the deciduous species followed patterns of nutrient content across substrate types, with higher resorption corresponding to lower bedrock concentrations. Work presented here indicates a complex plant response to available soil nutrients, wherein plant nutrient use compensates for variations in supply gradients and results in the maintenance of a narrow range in foliar stoichiometry. ?? 2008 Springer Science+Business Media, LLC.

  12. Effect of Carbohydrate Source and Cottonseed Meal Level in the Concentrate on Feed Intake, Nutrient Digestibility, Rumen Fermentation and Microbial Protein Synthesis in Swamp Buffaloes

    Directory of Open Access Journals (Sweden)

    M. Wanapat

    2013-07-01

    Full Text Available The objective of this study was to investigate the effect of carbohydrate source and cottonseed meal level in the concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in swamp buffaloes. Four, 4-yr old rumen fistulated swamp buffaloes were randomly assigned to receive four dietary treatments according to a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was carbohydrate source; cassava chip (CC and CC+rice bran at a ratio 3:1 (CR3:1, and factor B was level of cottonseed meal (CM; 109 g CP/kg (LCM and 328 g CP/kg (HCM in isonitrogenous diets (490 g CP/kg. Buffaloes received urea-treated rice straw ad libitum and supplemented with 5 g concentrate/kg BW. It was found that carbohydrate source did not affect feed intake, nutrient intake, digested nutrients, nutrient digestibility, ammonia nitrogen concentration, fungi and bacterial populations, or microbial protein synthesis (p>0.05. Ruminal pH at 6 h after feeding and the population of protozoa at 4 h after feeding were higher when buffalo were fed with CC than in the CR3:1 treatment (p0.05. Based on this experiment, concentrate with a low level of cottonseed meal could be fed with cassava chips as an energy source in swamp buffalo receiving rice straw.

  13. Electrical Conductivity and Chemical Composition of Soil Solution: Comparison of Solution Samplers in Tropical Soils

    Directory of Open Access Journals (Sweden)

    Davi Lopes do Carmo

    2016-01-01

    Full Text Available ABSTRACT Soil solution samplers may have the same working principle, but they differ in relation to chemical and physical characteristics, cost and handling, and these aspects exert influence on the chemical composition of the soil solution obtained. This study was carried out to evaluate, over time, the chemical composition of solutions extracted by Suolo Acqua, with the hydrophilic membrane (HM as a standard, using soils with contrasting characteristics, and to determine the relationship between electrical conductivity (EC and concentration of ions and pH of soil solution samples. This study was carried out under laboratory conditions, using three soils samples with different clay and organic matter (OM contents. Soil solution contents of F−, Cl−, NO−3, Br−, SO42−, Na+, NH4+, K+, Mg2+, Ca2+, were analyzed, as well as inorganic, organic, and total C contents, pH, and EC, in four successive sampling times. Soil solution chemical composition extracted by the Suolo Acqua sampler is similar to that collected by the HM, but the Suolo Acqua extracted more Na+ and soluble organic C than the HM solution. Solution EC, cation and anion concentrations, and soluble C levels are higher in the soil with greater clay and OM contents (Latossolo and Cambissolo in this case. Soil solution composition varied over time, with considerable changes in pH, EC, and nutrient concentrations, especially associated with soil OM. Thus, single and isolated sampling of the soil solution must be avoided, otherwise composition of the soil solution may not be correctly evaluated. Soil solution EC was regulated by pH, as well as the sum of cation and anion concentrations, and the C contents determined in the soil liquid phase.

  14. Isolation of transplutonium elements on ion exchangers from solutions of high salt concentration

    International Nuclear Information System (INIS)

    Guseva, L.I.; Tikhomirova, G.S.; Stepushkina, V.V.

    1985-01-01

    The behaviour of transplutonium elements (TPE) on cation and anion exchangers in aqueous alcoholic solutions of chlorides and nitrates of some alkali and alkaline earth metals depending on different factors: salt concentration, content of alcohol and of acid in the solution as well as the nature of a cation was studied. The data obtained were used to determine the optimal conditions of concentration of TPE on ion exchangers from solutions containing great quantities of salts. The advantages of the use of aqueous alcoholic solutions of nitric acid in the isolation of TPE are shown. (author)

  15. Efficacy of Fe(o,o-EDDHA) and Fe(o,p-EDDHA) isomers in supplying Fe to strategy I plants differs in nutrient solution and calcareous soil.

    Science.gov (United States)

    Rojas, Carmen L; Romera, Francisco J; Alcántara, Esteban; Pérez-Vicente, Rafael; Sariego, Cristina; Garcaí-Alonso, J Ignacio; Boned, Javier; Marti, Gabriel

    2008-11-26

    The FeEDDHA [iron(3+) ethylenediamine di(o-hydroxyphenylacetic) acid] is one of the most efficient iron chelates employed in the correction of iron clorosis in calcareous soils. FeEDDHA presents different positional isomers: the ortho-ortho (o,o), the ortho-para (o,p), and the para-para (p,p). Of these isomers, the p,p cannot chelate Fe in soil solution in a wide range of pH values, while both o,o and o,p can. The objective of this work was to compare the efficiency of both isomers (o,o and o,p) to provide Fe to two Strategy I plants (tomato and peach) in nutrient solution (pH approximately 6.0), as well as in calcareous soil (pH approximately 8.4; CALCIXEREPT). For this, chelates of both o,o-EDDHA and o,p-EDDHA with 57Fe (a nonradioactive isotope of Fe) were used, where the 57Fe acts as a tracer. The results obtained showed that the o,o isomer is capable of providing sufficient Fe to plants in both nutrient solution and calcareous soil. However, the o,p isomer is capable of providing sufficient Fe to plants in nutrient solution but not in calcareous soil.

  16. Increased sporulation of vesicular-arbuscular mycorrhizal fungi by manipulation of nutrient regimens.

    Science.gov (United States)

    Douds, D D; Schenck, N C

    1990-02-01

    Adjustment of pot culture nutrient solutions increased root colonization and sporulation of vesicular-arbuscular mycorrhizal (VAM) fungi. Paspalum notatum Flugge and VAM fungi were grown in a sandy soil low in N and available P. Hoagland nutrient solution without P enhanced sporulation in soil and root colonization of Acaulospora longula, Scutellospora heterogama, Gigaspora margarita, and a wide range of other VAM fungi over levels produced by a tap water control or nutrient solutions containing P. However, Glomus intraradices produced significantly more spores in plant roots in the tap water control treatment. The effect of the nutrient solutions was not due solely to N nutrition, because the addition of NH(4)NO(3) decreased both colonization and sporulation by G. margarita relative to levels produced by Hoagland solution without P.

  17. Stilbazolium Merocyanine Dye Determination in Different Solutions, Concentrations and Colloids Using SERS

    DEFF Research Database (Denmark)

    Pajchrowski, Grzegorz; Abdali, Salim; Nørbygaard, Thomas

    2006-01-01

    Surface Enhanced Raman Scattering (SERS) measurements were carried out on stilbazolium merocyanine dye in methanol and pyridine solvents. Both solutions were measured in series of concentrations, covering a range of 5·10-5 M to 5·10-8 M. In these measurements Ag and Au colloids were used and the ......Surface Enhanced Raman Scattering (SERS) measurements were carried out on stilbazolium merocyanine dye in methanol and pyridine solvents. Both solutions were measured in series of concentrations, covering a range of 5·10-5 M to 5·10-8 M. In these measurements Ag and Au colloids were used...... report here on the success of using SERS to obtain Raman spectra of merocyanine dye at very low concentration in an attempt of new approach, which can be used for further investigations of the dye. The SERS spectra will here be reported and the results from different solutions, colloids, concentrations...

  18. Produção do melão rendilhado em função da concentração de potássio na solução nutritiva e do número de frutos por planta Net melon yield as affected by potassium concentration in nutrient solution and number of fruits per plant

    Directory of Open Access Journals (Sweden)

    Caciana C. Costa

    2004-03-01

    Full Text Available O experimento foi conduzido em hidroponia (NFT, de junho a novembro de 2001, na UNESP, em Jaboticabal. A cultivar Bônus nº 2 foi cultivada sob blocos casualizados, em esquema de parcelas subdivididas, com seis repetições. Foram avaliados o número de frutos por planta (2; 3; 4 e fixação livre e a concentração de potássio na solução nutritiva (66; 115,5; 165 e 247,5 mg L-1 de K. Nas colheitas ocorridas entre 105 e 133 dias após o transplantio (DAT, foram obtidos 2,0; 2,5; 2,7 e 2,3 frutos por planta, enquanto que aos 85 DAT, o número de frutos fixados tinha sido, respectivamente, 2; 3; 4 e 6,2 frutos por planta. O incremento da concentração de potássio na solução nutritiva aumentou, inicialmente, o número de frutos fixados, e contribuiu, posteriormente, para a redução do abortamento dos frutos. Também, promoveu aumento no peso médio do segundo fruto. A produção e o peso médio dos frutos não foram influenciados pelo emprego de soluções nutritivas com concentração de potássio acima de 66 mg L-1. Entretanto, o número de frutos por planta afetou a produção e o peso médio dos frutos, promovendo respectivamente, aumento e redução à medida que maior foi o número de frutos por planta.The experiment was carried out using hidroponic solution (NFT from June to November-2001, in Jaboticabal, São Paulo State, Brazil. The 'Bonus nº 2' was cultivated in randomized blocks design, with split-plot scheme and six replications. Fruit number per plant (2; 3; 4 and free and potassium concentration in the nutrient solution (66; 115.5; 165 e 247.5 mg L-1 were the studied factors. At harvests [105 to 133 days after transplant (DAT], 2.0; 2.5; 2.7 and 2.3 fruits per plant were obtained, whereas at 85 DAT, 2; 3; 4 and 6.2 fruits had been set, respectively. Increasing potassium concentration in the nutrient solution improved initially fruit set and contributed later to reduce the fruit aborting in plants. Also the potassium promoted

  19. Effects of nutrient and lime additions in mine site rehabilitation strategies on the accumulation of antimony and arsenic by native Australian plants.

    Science.gov (United States)

    Wilson, Susan C; Leech, Calvin D; Butler, Leo; Lisle, Leanne; Ashley, Paul M; Lockwood, Peter V

    2013-10-15

    The effects of nutrient and lime additions on antimony (Sb) and arsenic (As) accumulation by native Australian and naturalised plants growing in two contaminated mine site soils (2,735 mg kg(-1) and 4,517 mg kg(-1) Sb; 826 mg kg(-1) and 1606 As mgkg(-1)) was investigated using a glasshouse pot experiment. The results indicated an increase in soil solution concentrations with nutrient addition in both soils and also with nutrient+lime addition for Sb in one soil. Metalloid concentrations in plant roots were significantly greater than concentrations in above ground plant parts. The metalloid transfer to above ground plant parts from the roots and from the soil was, however, low (ratio of leaf concentration/soil concentration≪1) for all species studied. Eucalyptus michaeliana was the most successful at colonisation with lowest metalloid transfer to above ground plant parts. Addition of nutrients and nutrients+lime to soils, in general, increased plant metalloid accumulation. Relative As accumulation was greater than that of Sb. All the plant species studied were suitable for consideration in the mine soil phytostabilisation strategies but lime additions should be limited and longer term trials also recommended. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Intelligent fiber optic sensor for solution concentration examination

    Science.gov (United States)

    Borecki, Michal; Kruszewski, Jerzy

    2003-09-01

    This paper presents the working principles of intelligent fiber-optic intensity sensor used for solution concentration examination. The sensor head is the ending of the large core polymer optical fiber. The head works on the reflection intensity basis. The reflected signal level depends on Fresnel reflection and reflection on suspended matter when the head is submersed in solution. The sensor head is mounted on a lift. For detection purposes the signal includes head submerging, submersion, emerging and emergence is measured. This way the viscosity turbidity and refraction coefficient has an effect on measured signal. The signal forthcoming from head is processed electrically in opto-electronic interface. Then it is feed to neural network. The novelty of presented sensor is implementation of neural network that works in generalization mode. The sensor resolution depends on opto-electronic signal conversion precision and neural network learning accuracy. Therefore, the number and quality of points used for learning process is very important. The example sensor application for examination of liquid soap concentration in water is presented in the paper.

  1. Assessment of Nutrient Concentration in Sokori River, Southwest ...

    African Journals Online (AJOL)

    Nutrient enrichment leads to excessive growth of primary producers as well as heterotrophic bacteria and fungi, which increases the metabolic activities of stream water leading to a depletion of dissolved oxygen. The low discharge of stream and its fairly flat terrain nature also influenced the metabolic activities in the mid- ...

  2. A field study to evaluate the impact of different factors on the nutrient pollutant concentrations in green roof runoff.

    Science.gov (United States)

    Wang, Xiaochen; Zhao, Xinhua; Peng, Chenrui; Zhang, Xinbo; Wang, Jianghai

    2013-01-01

    The objectives of this study are to investigate the impact of different factors on the nutrient pollutant concentrations in green roof runoff and to provide reference data for the engineering design of dual substrate layer green roofs. The data were collected from eight different trays under three kinds of artificial rains. The results showed that except for total phosphorus, dual substrate layer green roofs behaved as a sink for most of the nutrient pollutants (significant at p green roof and the depth of the adsorption substrates. Compared with the influence of the substrates, the influence of the plant density and drainage systems was small.

  3. Phytotoxic effects of nickel on yield and concentration of macro- and micro-nutrients in sunflower (Helianthus annuus L.) achenes.

    Science.gov (United States)

    Ahmad, Muhammad Sajid Aqeel; Ashraf, Muhammad; Hussain, Mumtaz

    2011-01-30

    The phytotoxic effects of varying levels of nickel (0, 10, 20, 30, and 40 mg L(-1)) on growth, yield and accumulation of macro- and micro-nutrients in leaves and achenes of sunflower (Helianthus annuus L.) were appraised in this study. A marked reduction in root and shoot fresh biomass was recorded at higher Ni levels. Nickel stress also caused a substantial decrease in all macro- and micro-nutrients in leaves and achenes. The lower level of Ni (10 mg L(-1)) had a non-significant effect on various yield attributes, but higher Ni levels considerably decreased these parameters. Higher Ni levels decreased the concentrations of Ca, Mn and Fe in achenes. In contrast, achene N, K, Zn, Mn and Cu decreased consistently with increasing level of Ni, even at lower level (10 mg L(-1)). Sunflower hybrid Hysun-33 had better yield and higher most of the nutrients in achenes as compared with SF-187. The maximum reduction in all parameters was observed at the maximum level of nickel (40 mg L(-1)) where almost all parameters were reduced more than 50% of those of control plants. In conclusion, the pattern of uptake and accumulation of different nutrients in sunflower plants were nutrient- and cultivar-specific under Ni-stress. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Irrigation water acidification to neutralize alkalinity for nursery crop production: Substrate pH, electrical conductivity, nutrient concentrations, and plant nutrition and growth

    Science.gov (United States)

    Liming agents in irrigation water, typically associated with carbonates and bicarbonates of calcium and magnesium, contribute to water alkalinity. Repeated application of LA to container crops can cause media-solution pH to rise overtime, that uncorrected, can lead to a nutrient availability imbalan...

  5. Electrical conductivity of the nutrient solution and plant density in aeroponic production of seed potato under tropical conditions (winter/spring

    Directory of Open Access Journals (Sweden)

    Alex Humberto Calori

    Full Text Available ABSTRACT The recent introduction in Brazil of production of quality seed potatoes in hydroponic systems, such as aeroponics, demands studies on the nutritional and crop management. Thus, this study evaluated the influence of electrical conductivity of the nutrient solution and plant density on the seed potato minitubers production in aeroponics system. The Agata and Asterix cultivars were produced in a greenhouse under tropical conditions (winter/spring. The experimental design was a randomized block in a split-split plot design. The plot consisted of 4 electrical conductivities of the nutrient solution (1.0; 2.0; 3.0; and 4.0 dS∙m−1; the subplot, of 4 plant densities (25; 44; 66; and 100 plants∙m−2; and the subsubplot, of the 2 potato cultivars (Ágata and Asterix, totaling 4 blocks. The 2.2 and 2.1 dS∙m−1 electrical conductivities yielded the highest productivity of seed potato minitubers, for Ágata and Asterix cultivars, respectively, regardless of plant density. For both cultivars, the highest yield was observed for the 100 plants∙m−2 density.

  6. Solute concentration affects bradykinin-mediated increases in renal prostaglandin E2

    International Nuclear Information System (INIS)

    Zenser, T.V.; Davis, E.S.; Rapp, N.S.; Davis, B.B.

    1981-01-01

    The effects of solute concentration on the bradykinin-mediated increase in inner medullary slice prostaglandin E2 (PGE2) synthesis were investigated. PG content was determined by specific RIA. Bradykinin stimulation was prevented by the addition of the following solutes to Krebs buffer: 1.0 M urea, 0.5 or 1.0 M NaCl, 0.5 or 1.0 M mannitol, 1.0 M urea plus 0.5 M NaCl, or 1.0 M mannitol plus 0.5 M NaCl. By contrast, basal PGE2 synthesis was increased by 1.0 M mannitol or by 1.0 M mannitol plus 0.5 M NaCl, but decreased by 1.0 M urea. Urea elicited a concentration-dependent, reversible inhibition of bradykinin stimulation, with 0.01 M urea being the lowest effective concentration. By contrast, basal PGE2 synthesis was only reduced at a urea concentration greater than 0.6 M. Arachidonic acid-mediated increases in both PGE2 and PGF2 alpha synthesis were not prevented by 1.0 M urea. The latter suggests that neither PG endoperoxide synthetase nor PG endoperoxide E isomerase are inhibited by urea. The data indicate that different hypertonic solutions have different effects on basal PG production, but all inhibit bradykinin stimulation

  7. Trends in nutrients

    Science.gov (United States)

    Heathwaite, A.L.; Johnes, P.J.; Peters, N.E.

    1996-01-01

    The roles of nitrogen (N) and phosphorus (P) as key nutrients determining the trophic status of water bodies are examined, and evidence reviewed for trends in concentrations of N and P species which occur in freshwaters, primarily in northern temperate environments. Data are reported for water bodies undergoing eutrophication and acidification, especially water bodies receiving increased nitrogen inputs through the atmospheric deposition of nitrogen oxides (NOx). Nutrient loading on groundwaters and surface freshwaters is assessed with respect to causes and rates of (change, relative rates of change for N and P, and implications of change for the future management of lakes, rivers and groundwaters. In particular, the nature and emphasis of studies for N species and P fractions in lakes versus rivers and groundwaters are contrasted. This review paper primarily focuses on results from North America and Europe, particularly for the UK where a wide range of data sets exists. Few nutrient loading data have been published on water bodies in less developed countries; however, some of the available data are presented to provide a global perspective. In general, N and P concentrations have increased dramatically (>20 times background concentrations) in many areas and causes vary considerably, ranging from urbanization to changes in agricultural practices.

  8. Changes in nutrients and decay rate of Ginkgo biloba leaf litter exposed to elevated O3 concentration in urban area

    Directory of Open Access Journals (Sweden)

    Wei Fu

    2018-03-01

    Full Text Available Ground-level ozone (O3 pollution has been widely concerned in the world, particularly in the cities of Asia, including China. Elevated O3 concentrations have potentially influenced growth and nutrient cycling of trees in urban forest. The decomposition characteristics of urban tree litters under O3 exposure are still poorly known. Ginkgo biloba is commonly planted in the cities of northern China and is one of the main tree species in the urban forest of Shenyang, where concentrations of ground-level O3 are very high in summer. Here, we hypothesized that O3 exposure at high concentrations would alter the decomposition rate of urban tree litter. In open-top chambers (OTCs, 5-year-old G. biloba saplings were planted to investigate the impact of elevated O3 concentration (120 ppb on changes in nutrient contents and decomposition rate of leaf litters. The results showed that elevated O3 concentration significantly increased K content (6.31 ± 0.29 vs 17.93 ± 0.40, P < 0.01 in leaves of G. biloba, significantly decreased the contents of total phenols (2.82 ± 0.93 vs 1.60 ± 0.44, P < 0.05 and soluble sugars (86.51 ± 19.57 vs 53.76 ± 2.40, P < 0.05, but did not significantly alter the contents of C, N, P, lignin and condensed tannins, compared with that in ambient air. Furthermore, percent mass remaining in litterbags after 150 days under ambient air and elevated O3 concentration was 56.0% and 52.8%, respectively. No significant difference between treatments was observed in mass remaining at any sampling date during decomposition. The losses of the nutrients in leaf litters of G. biloba showed significant seasonal differences regardless of O3 treatment. However, we found that elevated O3 concentration slowed down the leaf litter decomposition only at the early decomposition stage, but slightly accelerated the litter decomposition at the late stage (after 120 days. This study provides our understanding of the ecological processes regulating

  9. Reuse potential of laundry greywater for irrigation based on growth, water and nutrient use of tomato

    Science.gov (United States)

    Misra, R. K.; Patel, J. H.; Baxi, V. R.

    2010-05-01

    SummaryGreywater is considered as a valuable resource with a high reuse potential for irrigation of household lawns and gardens. However, there are possibilities of surfactant and sodium accumulation in soil from reuse of greywater which may affect agricultural productivity and environmental sustainability adversely. We conducted a glasshouse experiment to examine variation in growth, water and nutrient use of tomato ( Lycopersicon esculentum Mill. cv. Grosse Lisse) using tap water (TW), laundry greywater (GW) and solutions of low and high concentration of a detergent surfactant (LC and HC, respectively) as irrigation treatments. Each treatment was replicated five times using a randomised block design. Measurements throughout the experiment showed greywater to be significantly more alkaline and saline than the other types of irrigation water. Although all plants received 16 irrigations over a period of 9 weeks until flowering, there were little or no significant effects of irrigation treatments on plant growth. Soil water retention following irrigation reduced significantly when plants were irrigated with GW or surfactant solutions on only three of 12 occasions. On one occasion, water use measured as evapotranspiration (ET) with GW irrigation was similar to TW, but it was significantly higher than the plants receiving HC irrigation. At harvest, various components of plant biomass and leaf area for GW irrigated plants were found to be similar or significantly higher than the TW irrigated plants with a common trend of GW ⩾ TW > LC ⩾ HC. Whole-plant concentration was measured for 12 essential plant nutrients (N, P, K, Ca, Mg, S, Fe, Cu, Mn, Zn, Mo and B) and Na (often considered as a beneficial nutrient). Irrigation treatments affected the concentration of four nutrients (P, Fe, Zn and Na) and uptake of seven nutrients (P, K, Ca, Mg, Na, Fe and B) significantly. Uptake of these seven nutrients by tomato was generally in the order GW ⩾ TW > HC ⩾ LC. GW

  10. Polymer-Coated Urea Delays Growth and Accumulation of Key Nutrients in Aerobic Rice but Does Not Affect Grain Mineral Concentrations

    Directory of Open Access Journals (Sweden)

    Terry J. Rose

    2016-01-01

    Full Text Available Enhanced efficiency nitrogen (N fertilizers (EEFs may improve crop recovery of fertilizer-N, but there is evidence that some EEFs cause a lag in crop growth compared to growth with standard urea. Biomass and mineral nutrient accumulation was investigated in rice fertilized with urea, urea-3,4-dimethylpyrazole phosphate (DMPP and polymer-coated urea (PCU to determine whether any delays in biomass production alter the accumulation patterns, and subsequent grain concentrations, of key mineral nutrients. Plant growth and mineral accumulation and partitioning to grains did not differ significantly between plants fertilized with urea or urea-DMPP. In contrast, biomass accumulation and the accumulation of phosphorus, potassium, calcium, magnesium, copper, zinc and manganese were delayed during the early growth phase of plants fertilized with PCU. However, plants in the PCU treatment ultimately compensated for this by increasing growth and nutrient uptake during the latter vegetative stages so that no differences in biomass or nutrient accumulation generally existed among N fertilizer treatments at anthesis. Delayed biomass accumulation in rice fertilized with PCU does not appear to reduce the total accumulation of mineral nutrients, nor to have any impact on grain mineral nutrition when biomass and grain yields are equal to those of rice grown with urea or urea-DMPP.

  11. Effect of Sulfide Concentration on Copper Corrosion in Anoxic Chloride-Containing Solutions

    Science.gov (United States)

    Kong, Decheng; Dong, Chaofang; Xu, Aoni; Man, Cheng; He, Chang; Li, Xiaogang

    2017-04-01

    The structure and property of passive film on copper are strongly dependent on the sulfide concentration; based on this, a series of electrochemical methods were applied to investigate the effect of sulfide concentration on copper corrosion in anaerobic chloride-containing solutions. The cyclic voltammetry and x-ray photoelectron spectroscopy analysis demonstrated that the corrosion products formed on copper in anaerobic sulfide solutions comprise Cu2S and CuS. And the corrosion resistance of copper decreased with increasing sulfide concentration and faster sulfide addition, owing to the various structures of the passive films observed by the atomic force microscope and scanning electron microscope. A p-type semiconductor character was obtained under all experimental conditions, and the defect concentration, which had a magnitude of 1022-1023 cm-3, increased with increasing sulfide concentration, resulting in a higher rate of both film growth and dissolution.

  12. Physical Property Modeling of Concentrated Cesium Eluate Solutions, Part I - Derivation of Models

    Energy Technology Data Exchange (ETDEWEB)

    Choi, A.S.; Pierce, R. A.; Edwards, T. B.; Calloway, T. B.

    2005-09-15

    Major analytes projected to be present in the Hanford Waste Treatment Plant cesium ion-exchange eluate solutions were identified from the available analytical data collected during radioactive bench-scale runs, and a test matrix of cesium eluate solutions was designed within the bounding concentrations of those analytes. A computer model simulating the semi-batch evaporation of cesium eluate solutions was run in conjunction with a multi-electrolyte aqueous system database to calculate the physical properties of each test matrix solution concentrated to the target endpoints of 80% and 100% saturation. The calculated physical properties were analyzed statistically and fitted into mathematical expressions for the bulk solubility, density, viscosity, heat capacity and volume reduction factor as a function of temperature and concentration of each major analyte in the eluate feed. The R{sup 2} of the resulting physical property models ranged from 0.89 to 0.99.

  13. Intercropping of green garlic (Allium sativum L.) induces nutrient concentration changes in the soil and plants in continuously cropped cucumber (Cucumis sativus L.) in a plastic tunnel.

    Science.gov (United States)

    Xiao, Xuemei; Cheng, Zhihui; Meng, Huanwen; Liu, Lihong; Li, Hezi; Dong, Yinxin

    2013-01-01

    A pot-based experiment was conducted to investigate nutrient concentrations in cucumber plants intercropped with various amounts of green garlic. In addition, the soil nutrient contents were studied over two consecutive growing seasons. The results revealed that the accumulation of biomass and the nutritional elements nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and manganese (Mn) in cucumber plants were significantly increased for intercropping treatments during the two growing seasons compared to monoculture. Conversely, magnesium (Mg) concentrations were decreased in the cucumber plants. Shoot iron (Fe) concentrations decreased whereas root Fe concentrations increased in the intercropping system. Shoot and root zinc (Zn) concentrations decreased during the fall of 2011 but increased during the spring of 2012. Soil organic matter and available N, P and K were significantly increased as the proportion of intercropped green garlic increasing. Medium levels of intercropping green garlic improved cucumber nutrient concentrations the most. The regression analysis showed that the concentrations of most elements were significantly related to the amounts of garlic bulbs, especially the microelements in the spring 2011. The available soil N and organic matter were linearly related to the amounts of garlic bulbs. The results indicate that the nutritional status of the soil and plants of continuously cropped cucumber could be improved by intercropping with green garlic.

  14. Concentration and purification of plutonium solutions by means of ion-exchange columns

    Energy Technology Data Exchange (ETDEWEB)

    Durham, R W; Aikin, A M

    1953-02-15

    Equilibrium experiments using Dowex 50 ion-exchange resin and nitric acid solutions of Pu{sup 3+}, UO{sub 2}{sup 2+}, Fe{sup 2+} cations have yielded values for the absorption affinities for these ions. Trivalent plutonium was found to be far more strongly absorbed than UO{sub 2}{sup 2+} and Fe{sup 2+}. Column studies have shown that uranium can be completely separated from plutonium even when the initial concentration of uranium is very much greater than that of the plutonium. A plutonium concentration increase of about fifty-fold can be obtained from solutions about 10{sup -3} M in plutonium and 1.0M in nitric acid. The equation K{sub Pu}{sup 3+} = X{sub R} (1-X{sub S}){sup 3} C{sub S}{sup 2}/X{sub S} (1-X{sub R}){sup 3} C{sub R}{sup 2} for estimating the maximum amount of plutonium taken up by a column of resin of unit volume from a solution of total equivalent concentration, C{sub S} , has been shown to hold for values of C{sub S} up to 3 equivalents per litre. X{sub R}, the equivalent fraction of plutonium on the resin, is the number of equivalents of plutonium absorbed by the resin divided by the total capacity of the column. X{sub S}, the equivalent fraction of plutonium in solution, is the equivalent concentration of plutonium divided by the total equivalent concentration of cations in solution. C{sub R} is the total capacity of the resin in milli-equivalents per gram of dry resin. Recommendations have been made for the application and operation of ion-exchange columns in the Plutonium-Extraction Plant. (author)

  15. Salt type and concentration affect the viscoelasticity of polyelectrolyte solutions

    Science.gov (United States)

    Turkoz, Emre; Perazzo, Antonio; Arnold, Craig B.; Stone, Howard A.

    2018-05-01

    The addition of small amounts of xanthan gum to water yields viscoelastic solutions. In this letter, we show that the viscoelasticity of aqueous xanthan gum solutions can be tuned by different types of salts. In particular, we find that the decrease in viscoelasticity not only depends, as is known, on the salt concentration, but also is affected by the counterion ionic radius and the valence of the salt.

  16. Effect of ion concentrations on uranium absorption from sodium carbonate solutions

    International Nuclear Information System (INIS)

    Traut, D.E.; El Hazek, N.M.T.; Palmer, G.R.; Nichols, I.L.

    1979-01-01

    The effect of various ion concentrations on uranium absorption from a sodium carbonate solution by a strong-base, anion resin was investigated in order to help assure an adequate uranium supply for future needs. The studies were conducted to improve the recovery of uranium from in situ leach solutions by ion exchange. The effects of carbonate, bicarbonate, chloride, and sulfate ions were examined. Relatively low (less than 5 g/l) concentrations of chloride, sulfate, and bicarbonate were found to be detrimental to the absorption of uranium. High (greater than 10 g/l) carbonate concentrations also adversely affected the uranium absorption. In addition, the effect of initial resin form was investigated in tests of the chloride, carbonate, and bicarbonate forms; resin form was shown to have no effect on the absorption of uranium

  17. Modeling the interaction of light intensity, nutrient concentration and uranium toxicity in Lemna minor

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, E.; Horemans, N.; Vandenhove, H. [Belgian Nuclear Research Centre SCK-CEN (Belgium); Cedergreen, N. [University of Copenhagen (Denmark); Jager, T. [Vrije Universiteit Amsterdam (Netherlands)

    2014-07-01

    Radioecology aims at assessing the effect of radionuclides and radiation on the environment. Since we cannot test every possible environmental situation in the laboratory, we need modeling approaches to extrapolate the results of toxicity assays to environmentally relevant scenarios. Therefore, it is of crucial importance to understand the effect of relevant environmental factors, such as nutrients, temperature and light on the toxicity of the test. Radionuclides are often found to induce the production of reactive oxygen species (ROS). In plants, an overload of ROS can lead to disturbances of the photosynthetic system. Since the light intensity determines the efficiency of the photo-systems in plants, it can be expected to interact with the effect of radionuclides. The nutrient concentration of the test medium determines the physiological state of the plant, affecting in turn the plant's capability of dealing with stress and hence influences the toxicity of the contaminant. To study the interaction of stressors with environmental conditions, mechanistic effect modeling is promoted widely in ecotoxicology. In principle, the modelling aims at a mechanistic understanding of the different processes causing the stress individually, and integrating them in one framework to study their joint effect and possible interaction. We here present a mechanistic effect model for Lemna minor (common duckweed), which is based on Dynamic Energy Budget (DEB) theory. Models based on DEB have been used widely to study the effects of compounds on animals. Due to its general applicability to all types of organisms, it holds potential to be used for comparison of species and compounds in a broad context. Energy uptake from the environment is modeled explicitly, and metabolic rates are set to depend on temperature in DEB models. Therefore, they can be used to extrapolate effects to a wide range of environmentally relevant scenarios. Until now, the DEB research in ecotoxicology has

  18. Diagnosis of the nutrient compositional space of fruit crops

    Directory of Open Access Journals (Sweden)

    Léon-Étienne Parent

    2011-03-01

    Full Text Available Tissue analysis is a useful tool for the nutrient management of fruit orchards. The mineral composition of diagnostic tissues expressed as nutrient concentration on a dry weight basis has long been used to assess the status of 'pure' nutrients. When nutrients are mixed and interact in plant tissues, their proportions or concentrations change relatively to each other as a result of synergism, antagonism, or neutrality, hence producing resonance within the closed space of tissue composition. Ternary diagrams and nutrient ratios are early representations of interacting nutrients in the compositional space. Dual and multiple interactions were integrated by the Diagnosis and Recommendation Integrated System (DRIS into nutrient indexes and by Compositional Nutrient Diagnosis into centered log ratios (CND-clr. DRIS has some computational flaws such as using a dry matter index that is not a part as well as nutrient products (e.g. NxCa instead of ratios. DRIS and CND-clr integrate all possible nutrient interactions without defining an ad hoc interactive model. They diagnose D components while D-1 could be diagnosed in the D-compositional Hilbert space. The isometric log ratio (ilr coordinates overcome these problems using orthonormal binary nutrient partitions instead of dual ratios. In this study, it is presented a nutrient interactive model as well as computation methods for DRIS and CND-clr and CND-ilr coordinates (CND-ilr using leaf analytical data from an experimental apple orchard in Southwestern Quebec, Canada. It was computed the Aitchison and Mahalanobis distances across ilr coordinates as measures of nutrient imbalance. The effect of changing nutrient concentrations on ilr coordinates are simulated to identify the ones contributing the most to nutrient imbalance.

  19. Increased Sporulation of Vesicular-Arbuscular Mycorrhizal Fungi by Manipulation of Nutrient Regimens †

    OpenAIRE

    Douds, David D.; Schenck, N. C.

    1990-01-01

    Adjustment of pot culture nutrient solutions increased root colonization and sporulation of vesicular-arbuscular mycorrhizal (VAM) fungi. Paspalum notatum Flugge and VAM fungi were grown in a sandy soil low in N and available P. Hoagland nutrient solution without P enhanced sporulation in soil and root colonization of Acaulospora longula, Scutellospora heterogama, Gigaspora margarita, and a wide range of other VAM fungi over levels produced by a tap water control or nutrient solutions contain...

  20. Molecular Effects of Concentrated Solutes on Protein Hydration, Dynamics, and Electrostatics.

    Science.gov (United States)

    Abriata, Luciano A; Spiga, Enrico; Peraro, Matteo Dal

    2016-08-23

    Most studies of protein structure and function are performed in dilute conditions, but proteins typically experience high solute concentrations in their physiological scenarios and biotechnological applications. High solute concentrations have well-known effects on coarse protein traits like stability, diffusion, and shape, but likely also perturb other traits through finer effects pertinent at the residue and atomic levels. Here, NMR and molecular dynamics investigations on ubiquitin disclose variable interactions with concentrated solutes that lead to localized perturbations of the protein's surface, hydration, electrostatics, and dynamics, all dependent on solute size and chemical properties. Most strikingly, small polar uncharged molecules are sticky on the protein surface, whereas charged small molecules are not, but the latter still perturb the internal protein electrostatics as they diffuse nearby. Meanwhile, interactions with macromolecular crowders are favored mainly through hydrophobic, but not through polar, surface patches. All the tested small solutes strongly slow down water exchange at the protein surface, whereas macromolecular crowders do not exert such strong perturbation. Finally, molecular dynamics simulations predict that unspecific interactions slow down microsecond- to millisecond-timescale protein dynamics despite having only mild effects on pico- to nanosecond fluctuations as corroborated by NMR. We discuss our results in the light of recent advances in understanding proteins inside living cells, focusing on the physical chemistry of quinary structure and cellular organization, and we reinforce the idea that proteins should be studied in native-like media to achieve a faithful description of their function. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  1. Nutrient fluxes at the landscape level and the R* rule

    Science.gov (United States)

    Ju, Shu; DeAngelis, Donald L.

    2010-01-01

    Nutrient cycling in terrestrial ecosystems involves not only the vertical recycling of nutrients at specific locations in space, but also biologically driven horizontal fluxes between different areas of the landscape. This latter process can result in net accumulation of nutrients in some places and net losses in others. We examined the effects of such nutrient-concentrating fluxes on the R* rule, which predicts that the species that can survive in steady state at the lowest level of limiting resource, R*, can exclude all competing species. To study the R* rule in this context, we used a literature model of plant growth and nutrient cycling in which both nutrients and light may limit growth, with plants allocating carbon and nutrients between foliage and roots according to different strategies. We incorporated the assumption that biological processes may concentrate nutrients in some parts of the landscape. We assumed further that these processes draw nutrients from outside the zone of local recycling at a rate proportional to the local biomass density. Analysis showed that at sites where there is a sufficient biomass-dependent accumulation of nutrients, the plant species with the highest biomass production rates (roughly corresponding to the best competitors) do not reduce locally available nutrients to a minimum concentration level (that is, minimum R*), as expected from the R* rule, but instead maximize local nutrient concentration. These new results require broadening of our understanding of the relationships between nutrients and vegetation competition on the landscape level. The R* rule is replaced by a more complex criterion that varies across a landscape and reduces to the R* rule only under certain limiting conditions.

  2. Effects of soil characteristics on grape juice nutrient concentrations and other grape quality parameters in Shiraz

    Science.gov (United States)

    Concepción Ramos, Maria; Romero, Maria Paz

    2017-04-01

    This study investigated the response of grapes to soil properties in the variety Shiraz (SH) cultivated in the Costers de Segre Designation of Origin (NE, Spain). The research was carried out in two areas with differences in vigor, which was examined using the Normalized Difference Vegetation Index (NDVI). Soil properties such as organic matter content, pH, electrical conductivity and nutrients (N, P, K, Ca, Mg, Cu, Zn and Mn) were analysed in the two areas. Soil analyses were limited to the upper 40 cm. Soil N-NO3 was measured in 2M KCl extracts. Assimilable phosphorus was analysed by extraction with 0.5 M NaHCO3 at pH 8.5 using the Olsen method. The available K, Ca and Mg were evaluated in hemaaxinecobalt trichloride extracts and the available fraction of Cu, Zn, Mn and Fe in DTPA- trietanolamine extracts, by spectroscopy atomic emission/absorption. Berry grapes were collected at maturity. Nutrients in grape juice (K, Ca, Mg Cu, Zn, Mn and Fe) were determined after a microwave hydrogen peroxide digestion in a closed vessel microwave digestion system and measured by spectroscopy. Other grape properties that determine grape quality such as pH, berry weight and sugar content were analysed using the methods proposed by the OIV. Differences in soil properties were observed between plots, which determined the differences in vigour. The vines with lower vigour were grown in the soils with higher pH, electrical conductivity and silt content, which had in addition higher Ca, Mg and K available levels as well as higher levels of Fe and Mn than the soil in which vines had higher vigour. However, the available fraction of Cu and Zn was smaller. Similar differences in nutrient concentration in the berry were observed for all nutrients except for Cu. Grape juice pH and total soluble solids (°Brix) were higher in the most vigorous vines. However, the differences in berry weight and total acidity at ripening were not significant. Keywords: acidity; berry weight; nutrients; p

  3. Effect of organic and inorganic fertilizers on nutrient concentrations ...

    African Journals Online (AJOL)

    Yomi

    2012-01-24

    Jan 24, 2012 ... food energy and basic nutrients for proper nutrition of man. ... 2008). Irrespective of the variety, crop yield is a direct ..... had recently formed the research drive of scientists so as .... Bioresource Technology for Sustainable.

  4. Adição de cromo hexavalente no crescimento, nodulação e absorção de nutrientes em soja Hexavalent chromium effects on soybeans growth, nitrogen fixation and nutrients absorption

    Directory of Open Access Journals (Sweden)

    Danilo Dufech Castilhos

    2001-12-01

    Full Text Available Foram avaliados os efeitos de doses crescentes de Cr6+ sobre a produção de matéria seca, absorção de nutrientes e fixação biológica de nitrogênio em plantas de soja. Antes da semeadura, as sementes foram tratadas com inóculo turfoso contendo Bradyrhizobium japonicum. As plantas foram cultivadas durante 40 dias em vasos "Leonard" que continha areia na parte superior e solução nutritiva sem nitrogênio na parte inferior. Os tratamentos constaram das seguintes doses de Cr6+ (K2Cr2O7 na solução nutritiva: 0, 5, 10, 20 e 40mg -1. Foi constatado que concentrações de Cr6+ maiores que 5mg -1 diminuíram a produção de matéria seca da parte aérea e radicular da soja, o número e peso de nódulos secos de Bradyrhizobium, como também a fixação biológica de nitrogênio e a absorção de P, K, Ca e Mg. Teores de Cr na parte aérea de plantas de soja superiores a 3,4mg Kg-1 podem ser considerados fitotóxicos.This study was carried out to evaluate the effect of hexavalent chromium on dry matter production, nutrient uptake and nitrogen fixation in soybeans (Glycine max The seeds were inoculated with comercial strains of Bradyrhizobium japonicum (SEMIA 587 and 5019 and the plants were grown in "Leonard Jars" containing washed sand in the upper portion and nutrient solution (without N in the lower. Five Cr6+ concentrations were used: 0, 5, 10, 20 e 40mg -1 in the nutrient solution. Concentrations of Cr6+ above 5mg -1 decreased plants and nodules dry matter production, number of nodules, nitrogen fixation and P, K, Ca e Mg uptake. Chromium concentrations in soybean tops above 3,4mg kg-1 were considered phytotoxic.

  5. Absolute nutrient concentration measurements in cell culture media: 1H q-NMR spectra and data to compare the efficiency of pH-controlled protein precipitation versus CPMG or post-processing filtering approaches

    Directory of Open Access Journals (Sweden)

    Luca Goldoni

    2016-09-01

    Full Text Available The NMR spectra and data reported in this article refer to the research article titled “A simple and accurate protocol for absolute polar metabolite quantification in cell cultures using q-NMR” [1]. We provide the 1H q-NMR spectra of cell culture media (DMEM after removal of serum proteins, which show the different efficiency of various precipitating solvents, the solvent/DMEM ratios, and pH of the solution. We compare the data of the absolute nutrient concentrations, measured by PULCON external standard method, before and after precipitation of serum proteins and those obtained using CPMG (Carr-Purcell-Meiboom-Gill sequence or applying post-processing filtering algorithms to remove, from the 1H q-NMR spectra, the proteins signal contribution. For each of these approaches, the percent error in the absolute value of every measurement for all the nutrients is also plotted as accuracy assessment. Keywords: 1H NMR, pH-controlled serum removal, PULCON, Accuracy, CPMG, Deconvolution

  6. Investigation into sorption of uranium fron its high-concentrated nitric acid solutions on resin AMP

    International Nuclear Information System (INIS)

    Savel'eva, V.I.; Sudarikov, B.N.; Kireeva, G.N.; Ryzhkova, V.N.; Kandaryuk, V.V.

    1976-01-01

    Sorption of uranium has been studied on strongly basic anion-exchange resin from nitric acid solutions with concentration in metal 10-150 g/l in presence of sodium, calcium, and aluminium nitrates. Sorption of uranium from solutions has been performed by the static method with the aid of contacting the initial solution with airdry resin for 4 hours, resin to solution ratio being 1:12.5. It has been established that sorption of uranium increases with a rise in concentration of salting out agents in the following order: Al(NO 3 ) 3 > Ca(NO 3 ) 2 > Na(NO 3 ). It has been shown spectrophotometricatly that in solutions of nitrates and HNO 3 with a concentration 3 exceeds 6 mol/l

  7. Reuse of hydroponic waste solution.

    Science.gov (United States)

    Kumar, Ramasamy Rajesh; Cho, Jae Young

    2014-01-01

    Attaining sustainable agriculture is a key goal in many parts of the world. The increased environmental awareness and the ongoing attempts to execute agricultural practices that are economically feasible and environmentally safe promote the use of hydroponic cultivation. Hydroponics is a technology for growing plants in nutrient solutions with or without the use of artificial medium to provide mechanical support. Major problems for hydroponic cultivation are higher operational cost and the causing of pollution due to discharge of waste nutrient solution. The nutrient effluent released into the environment can have negative impacts on the surrounding ecosystems as well as the potential to contaminate the groundwater utilized by humans for drinking purposes. The reuse of non-recycled, nutrient-rich hydroponic waste solution for growing plants in greenhouses is the possible way to control environmental pollution. Many researchers have successfully grown several plant species in hydroponic waste solution with high yield. Hence, this review addresses the problems associated with the release of hydroponic waste solution into the environment and possible reuse of hydroponic waste solution as an alternative resource for agriculture development and to control environmental pollution.

  8. Separation and Concentration of Succinic Adic from Multicomponent Aqueous Solutions by Nanofiltration Technique

    Directory of Open Access Journals (Sweden)

    Antczak Jerzy

    2014-06-01

    Full Text Available This paper applies the determined suitability of nanofiltration (NF membrane separation for selective isolation and concentration of succinic acid from aqueous solutions which are post-fermentation multicomponent fluids. The study analyzed the influence of concentration and the pH of the separated solutions on the efficiency and selectivity of NF process that runs in a module equipped with a ceramic membrane. Moreover, the effect of applied trans-membrane pressure on the retention of succinic acid and sodium succinate has been studied. The investigations have shown that in the used NF module the retention of succinic acid salt is equal almost 50% in the case of a three-component model solution, although the degree of retention depends on both the transmembrane pressure and the initial concentration of separated salt.

  9. Development of system on predicting uranium concentration from pregnant solution

    International Nuclear Information System (INIS)

    Yi Weiping

    2004-01-01

    Uranium concentration from pregnant solution is primary index of process for in-situ leaching of uranium, and the suitable method with which to predicate this index and effective means to solve it with were continuously studied hard. SPUC-system on predicting uranium concentration based on GM model of gray system theory is developed, and the mathematical model, constitution, function and theory foundation of this system are introduced. (authors)

  10. Sediment and solute transport in a mountainous watershed in Valle del Cauca, Colombia

    Science.gov (United States)

    Guzman, Christian; Hoyos Villada, Fanny; Morales Vargas, Amalia; Rivera, Baudelino; Da Silva, Mayesse; Moreno Padilla, Pedro; Steenhuis, Tammo

    2015-04-01

    Sediment samples and solute concentrations were measured from the La Vega micro watershed in the southwestern region of the Colombian Andes. A main goal of this study was to improve prediction of soil surface and soil nutrient changes, based on field measurements, within small basin of the Aguaclara watershed network receiving different types of conservation measures. Two modeling approaches for stream discharge and sediment transport predictions were used with one of these based on infiltration-excess and the other on saturation-excess runoff. These streams are a part of a recent initiative from a water fund established by Asobolo, Asocaña, and Cenicaña in collaboration with the Natural Capital Project to improve conservation efforts and monitor their effects. On-site soil depth changes, groundwater depth measurements, and soil nutrient concentrations were also monitored to provide more information about changes within this mountainous watershed during one part of the yearly rainy season. This information is being coupled closely with the outlet sediment concentration and solute concentration patterns to discern correlations between scales. Lateral transects in the upper, middle, and lower part of the hillsides in the La Vega micro watershed showed differences in soil nutrient status and soil surface depth changes. The model based on saturation-excess, semi-distributed hydrology was able to reproduce discharge and sediment transport rates as well as the initially used infiltration excess model indicating available options for comparison of conservation changes in the future.

  11. Effects of Organic Corrosion Inhibitor and Chloride Ion Concentration on Steel Depassivation and Repassivation in Solution

    Institute of Scientific and Technical Information of China (English)

    WANG Zixiao; YU Lei; LIU Zhiyong; SONG Ning

    2015-01-01

    Effect of an organic corrosion inhibitor (OCI) named PCI-2014 added in chloride solution on the critical chlo-ride concentration of mild steel depassivation and the critical OCI concentrations for repairing the steel in different chlo-ride solution were investigated. The results show that the critical chloride concentration increases exponentially with raises of PCI-2014 concentration in the solution. Within a certain chloride ion concentration range, the critical PCI-2014 concentration for repairing the corroded steel is also increases exponentially with enhancement of chloride content in the solution. Atomic force microscopy images display the molecular particles of inhibitor are adsorbed on the steel surface and formed a protective layer. Analysis of X-ray photoelectron spectroscopy shows the chloride ions at the surface of steel are displaced by atoms or molecules of the inhibitor in chloride condition.

  12. Nutrient and Bacteria Concentrations in the Coastal Waters off ...

    African Journals Online (AJOL)

    ammonium, nitrate, nitrite, soluble reactive phosphorous) and bacteria (total and faecal coliforms) in the waters off Zanzibar Town. The study covered both the SE and NE monsoon and the two transition periods for a total of one year. Nutrient ...

  13. Methods to homogenize electrochemical concentration cell (ECC ozonesonde measurements across changes in sensing solution concentration or ozonesonde manufacturer

    Directory of Open Access Journals (Sweden)

    T. Deshler

    2017-06-01

    Full Text Available Ozone plays a significant role in the chemical and radiative state of the atmosphere. For this reason there are many instruments used to measure ozone from the ground, from space, and from balloons. Balloon-borne electrochemical cell ozonesondes provide some of the best measurements of the ozone profile up to the mid-stratosphere, providing high vertical resolution, high precision, and a wide geographic distribution. From the mid-1990s to the late 2000s the consistency of long-term records from balloon-borne ozonesondes has been compromised by differences in manufacturers, Science Pump (SP and ENSCI (EN, and differences in recommended sensor solution concentrations, 1.0 % potassium iodide (KI and the one-half dilution: 0.5 %. To investigate these differences, a number of organizations have independently undertaken comparisons of the various ozonesonde types and solution concentrations, resulting in 197 ozonesonde comparison profiles. The goal of this study is to derive transfer functions to allow measurements outside of standard recommendations, for sensor composition and ozonesonde type, to be converted to a standard measurement and thus homogenize the data to the expected accuracy of 5 % (10 % in the stratosphere (troposphere. Subsets of these data have been analyzed previously and intermediate transfer functions derived. Here all the comparison data are analyzed to compare (1 differences in sensor solution composition for a single ozonesonde type, (2 differences in ozonesonde type for a single sensor solution composition, and (3 the World Meteorological Organization's (WMO and manufacturers' recommendations of 1.0 % KI solution for Science Pump and 0.5 % KI for ENSCI. From the recommendations it is clear that ENSCI ozonesondes and 1.0 % KI solution result in higher amounts of ozone sensed. The results indicate that differences in solution composition and in ozonesonde type display little pressure dependence at pressures

  14. Intercropping of Green Garlic (Allium sativum L.) Induces Nutrient Concentration Changes in the Soil and Plants in Continuously Cropped Cucumber (Cucumis sativus L.) in a Plastic Tunnel

    Science.gov (United States)

    Xiao, Xuemei; Cheng, Zhihui; Meng, Huanwen; Liu, Lihong; Li, Hezi; Dong, Yinxin

    2013-01-01

    A pot-based experiment was conducted to investigate nutrient concentrations in cucumber plants intercropped with various amounts of green garlic. In addition, the soil nutrient contents were studied over two consecutive growing seasons. The results revealed that the accumulation of biomass and the nutritional elements nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and manganese (Mn) in cucumber plants were significantly increased for intercropping treatments during the two growing seasons compared to monoculture. Conversely, magnesium (Mg) concentrations were decreased in the cucumber plants. Shoot iron (Fe) concentrations decreased whereas root Fe concentrations increased in the intercropping system. Shoot and root zinc (Zn) concentrations decreased during the fall of 2011 but increased during the spring of 2012. Soil organic matter and available N, P and K were significantly increased as the proportion of intercropped green garlic increasing. Medium levels of intercropping green garlic improved cucumber nutrient concentrations the most. The regression analysis showed that the concentrations of most elements were significantly related to the amounts of garlic bulbs, especially the microelements in the spring 2011. The available soil N and organic matter were linearly related to the amounts of garlic bulbs. The results indicate that the nutritional status of the soil and plants of continuously cropped cucumber could be improved by intercropping with green garlic. PMID:23637994

  15. Intercropping of green garlic (Allium sativum L. induces nutrient concentration changes in the soil and plants in continuously cropped cucumber (Cucumis sativus L. in a plastic tunnel.

    Directory of Open Access Journals (Sweden)

    Xuemei Xiao

    Full Text Available A pot-based experiment was conducted to investigate nutrient concentrations in cucumber plants intercropped with various amounts of green garlic. In addition, the soil nutrient contents were studied over two consecutive growing seasons. The results revealed that the accumulation of biomass and the nutritional elements nitrogen (N, phosphorus (P, potassium (K, calcium (Ca and manganese (Mn in cucumber plants were significantly increased for intercropping treatments during the two growing seasons compared to monoculture. Conversely, magnesium (Mg concentrations were decreased in the cucumber plants. Shoot iron (Fe concentrations decreased whereas root Fe concentrations increased in the intercropping system. Shoot and root zinc (Zn concentrations decreased during the fall of 2011 but increased during the spring of 2012. Soil organic matter and available N, P and K were significantly increased as the proportion of intercropped green garlic increasing. Medium levels of intercropping green garlic improved cucumber nutrient concentrations the most. The regression analysis showed that the concentrations of most elements were significantly related to the amounts of garlic bulbs, especially the microelements in the spring 2011. The available soil N and organic matter were linearly related to the amounts of garlic bulbs. The results indicate that the nutritional status of the soil and plants of continuously cropped cucumber could be improved by intercropping with green garlic.

  16. Nutrient fluxes from coastal California catchments with suburban development

    Science.gov (United States)

    Melack, J. M.; Leydecker, A.; Beighley, E.; Robinson, T.; Coombs, S.

    2005-12-01

    Numerous streams originate in the mountains fringing California's coast and transport nutrients into coastal waters. In central California, these streams traverse catchments with land covers including chaparral, grazed grasslands, orchards, industrial agriculture and suburban and urban development. Fluvial nutrient concentrations and fluxes vary as a function of these land covers and as a function of considerable fluctuations in rainfall. As part of a long-term investigation of mobilization and fluvial transport of nutrients in catchments bordering the Santa Barbara Channel we have intensively sampled nutrient concentrations and measured discharge during storm and base flows in multiple catchments and subcatchments. Volume-weighted mean concentrations of nitrate generally ranged from 5 to 25 micromolar in undeveloped areas, increased to about 100 micromolar for suburban and most agricultural catchments, and were in excess of 1000 micromolar in catchments with greenhouse-based agriculture. Phosphate concentrations ranged from 2 to 20 micromolar among the catchments. These data are used to examine the premise that the suburbanized portion of the catchments is the primary source of nutrients to the streams.

  17. Solution Behavior and Activity of a Halophilic Esterase under High Salt Concentration

    Science.gov (United States)

    Rao, Lang; Zhao, Xiubo; Pan, Fang; Li, Yin; Xue, Yanfen; Ma, Yanhe; Lu, Jian R.

    2009-01-01

    Background Halophiles are extremophiles that thrive in environments with very high concentrations of salt. Although the salt reliance and physiology of these extremophiles have been widely investigated, the molecular working mechanisms of their enzymes under salty conditions have been little explored. Methodology/Principal Findings A halophilic esterolytic enzyme LipC derived from archeaon Haloarcula marismortui was overexpressed from Escherichia coli BL21. The purified enzyme showed a range of hydrolytic activity towards the substrates of p-nitrophenyl esters with different alkyl chains (n = 2−16), with the highest activity being observed for p-nitrophenyl acetate, consistent with the basic character of an esterase. The optimal esterase activities were found to be at pH 9.5 and [NaCl] = 3.4 M or [KCl] = 3.0 M and at around 45°C. Interestingly, the hydrolysis activity showed a clear reversibility against changes in salt concentration. At the ambient temperature of 22°C, enzyme systems working under the optimal salt concentrations were very stable against time. Increase in temperature increased the activity but reduced its stability. Circular dichroism (CD), dynamic light scattering (DLS) and small angle neutron scattering (SANS) were deployed to determine the physical states of LipC in solution. As the salt concentration increased, DLS revealed substantial increase in aggregate sizes, but CD measurements revealed the maximal retention of the α-helical structure at the salt concentration matching the optimal activity. These observations were supported by SANS analysis that revealed the highest proportion of unimers and dimers around the optimal salt concentration, although the coexistent larger aggregates showed a trend of increasing size with salt concentration, consistent with the DLS data. Conclusions/Significance The solution α-helical structure and activity relation also matched the highest proportion of enzyme unimers and dimers. Given that

  18. Determination of the unfrozen water content of maximally freeze-concentrated carbohydrate solutions.

    Science.gov (United States)

    Hatley, R H; Mant, A

    1993-08-01

    The heat capacity change at T'g has been studied in freeze-concentrated carbohydrate solutions. The values obtained have been compared with those found for high concentration solutions that do not undergo freezing above Tg. The analysis has indicated that the freezing process influences the degree of stress in the glassy phase. This results in a complex power-time curve when frozen solutions are heated in a differential scanning calorimeter. The endotherm produced by the stress relaxation can cause considerable error in W'g measurement obtained by any method that relies on the integration of the power-time curve. A more reliable method for W'g determination is via the intersection of T'g with a previously prepared Tg/Wg calibration curve.

  19. Tolerância de genótipos de trigo comum, trigo duro e triticale à toxicidade de alumínio em soluções nutritivas Tolerance of bread wheat, durum wheat and triticale genotypes to aluminum toxicity in nutrient solution

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Oliveira Camargo

    2006-01-01

    Full Text Available Foi estudado o comportamento diferencial de 12 genótipos de trigo comum (Triticum aestivum L., um genótipo de trigo duro (Triticum durum L., e um de triticale (Triticosecale sp em soluções nutritivas de tratamento contendo duas concentrações salinas (1/5 e 1/10 da completa e seis concentrações de alumínio ( 0, 2, 4, 6, 8 e 10 mg L-1, à temperatura de 25 ± 1ºC e pH 4,0. Foram utilizadas dez plântulas por parcela e quatro repetições. A tolerância foi medida pela capacidade de as raízes primárias continuarem a crescer em solução sem alumínio, após permanecer 48 horas em solução nutritiva completa, contendo uma concentração conhecida de alumínio combinada com cada uma das concentrações salinas. Os genótipos de trigo comum IAC-289, IAC-350 e IAC-370 e a cultivar controle Anahuac, e os genótipos de trigo duro IAC-1003 e de triticale IAC-5 foram os mais sensíveis a níveis crescentes de Al3+nas soluções nutritivas de tratamento e, portanto, somente seriam indicados para cultivo em solos corrigidos. Os genótipos de trigo comum IAC-24 e IAC-378 e a cultivar controle BH-1146 destacaram-se pela tolerância à toxicidade de Al3+, com potencial para uso em solos ácidos e como fontes genéticas de tolerância nos futuros cruzamentos. Os sintomas de toxicidade de alumínio foram maiores com a elevação da concentração de alumínio e da diminuição das concentrações de sais da solução nutritiva para todos os genótipos estudados.Twelve bread wheat (Triticum aestivum L., one durum wheat (Triticum durum L. and one triticale (Triticosecale sp genotypes were studied in nutrient solutions with a high salt concentration in experiment 1 and a weak salt concentration in experiment 2, for aluminum tolerance at six levels: 0, 2, 4, 6, 8 and 10 mg L-1, under temperature 25 ± 1ºC and pH 4,0. Four replications were used per experiment. Aluminum tolerance was evaluated by measuring root growth in an aluminum-free complete

  20. Investigation of the effects of aluminum stress on some macro and micro-nutrient contents of the seedlings of lycopersicon esculentum mill. by using scanning electron microscope

    International Nuclear Information System (INIS)

    Colak, G.; Catak, E.; Baykul, M.C.

    2014-01-01

    This study was planned to see the affect of aluminum stress on plant nutrition and metabolism. The effects of aluminum stress on uptake level of some macro- and micro-nutrients from the nutrition solution into the seedlings of Lycopersicon esculentum Mill. and on mobilization of some nutrient elements in the seedlings were examined at the level of epidermal cells. The elemental structure of root, hypocotyl and cotyledon epidermal cells were determined by Energy Dispersive Xray Microanalysis (EDX) performed in a local area 50 nm in diameter at the level of a single epidermal cell cytoplasm by using low vacuum (24 pascal ) Scanning Electron Microscope. EDX analysis revealed that aluminum content of the cells was increasing with the increased concentrations of aluminum in the nutrient solution and that aluminum largelyaccumulated in the roots. Aluminum concentration was much higher in the root epidermal cells of the seedlings incubated in aluminum containing media for 17 days without adding any nutrient solution; it was also true for the local EDX analysis of radicle epidermal cells from the same series. Aluminum stress was found to tend to modify the plant nutritional element content of the cells and this was particularly of critical importance in terms of some macro- and micro-nutrients. The assessments performed at the level of epidermal cells of young seedlings of Lycopersicon esculentum suggest that aluminum stress leads to an absolute change in the plant nutritional element composition of the cells and in the mobilization of some nutritional elements in the seedlings. (author)

  1. The Relative Concentrations of Nutrients and Toxins Dictate Feeding by a Vertebrate Browser, the Greater Glider Petauroides volans.

    Directory of Open Access Journals (Sweden)

    Lora M Jensen

    Full Text Available Although ecologists believe that vertebrate herbivores must select a diet that allows them to meet their nutritional requirements, while avoiding intoxication by plant secondary metabolites, this is remarkably difficult to show. A long series of field and laboratory experiments means that we have a good understanding of the factors that affect feeding by leaf-eating marsupials. This knowledge and the natural intraspecific variation in Eucalyptus chemistry allowed us to test the hypothesis that the feeding decisions of greater gliders (Petauroides volans depend on the concentrations of available nitrogen (incorporating total nitrogen, dry matter digestibility and tannins and of formylated phloroglucinol compounds (FPCs, potent antifeedants unique to Eucalyptus. We offered captive greater gliders foliage from two species of Eucalyptus, E. viminalis and E. melliodora, which vary naturally in their concentrations of available nitrogen and FPCs. We then measured the amount of foliage eaten by each glider and compared this with our laboratory analyses of foliar total nitrogen, available nitrogen and FPCs for each tree offered. The concentration of FPCs was the main factor that determined how much gliders ate of E. viminalis and E. melliodora, but in gliders fed E. viminalis the concentration of available nitrogen was also a significant influence. In other words, greater gliders ate E. viminalis leaves with a particular combination of FPCs and available nitrogen that maximised the nutritional gain but minimised their ingestion of toxins. In contrast, the concentration of total nitrogen was not correlated with feeding. This study is among the first to empirically show that browsing herbivores select a diet that balances the potential gain (available nutrients and the potential costs (plant secondary chemicals of eating leaves. The major implication of the study is that it is essential to identify the limiting nutrients and relevant toxins in a system in

  2. Irrigation water acidification to neutralize alkalinity for nursery crop production: Substrate pH, electrical conductivity, and nutrient concentrations; and plant nutrition and growth

    Science.gov (United States)

    Liming agents (LA) in irrigation water, typically associated with carbonates and bicarbonates of calcium (Ca) and magnesium (Mg), contribute to water alkalinity. Repeated application of LA to container crops can cause media-solution pH to rise overtime, that uncorrected, can lead to a nutrient avail...

  3. Report Assesses Nutrient Pollution in U.S. Streams and Aquifers

    Science.gov (United States)

    Showstack, Randy

    2010-10-01

    Concentrations of nutrients in many U.S. streams and aquifers have remained the same or have increased since the early 1990s, according to a new decadal assessment entitled “Nutrients in the nation's streams and groundwater, 1992-2004,” released by the U.S. Geological Survey (USGS) on 24 September. “Despite improvements in water quality made by reducing point sources of nutrients, our data show that nonpoint sources of nutrients have resulted in concentrations of both nitrogen and phosphorus far above criteria recommended by [the U.S. Environmental Protection Agency] for the protection of aquatic life,” Neil Dubrovsky, project chief for USGS's National Water-Quality Assessment (NAWQA) Program, said at a briefing when the report was released. While USGS continues to sample for nutrient concentrations, the report assessment period concluded in 2004.

  4. Development of a soilless growing system for blueberries (Vaccinium corymbosum): nutrient demand and nutrient solution

    NARCIS (Netherlands)

    Voogt, W.; Dijk, van P.; Douven, F.; Maas, van der M.P.

    2014-01-01

    Although the majority of blueberries in The Netherlands are soil grown, interest in soilless culture has increased recently. Modern cultivation with high yield and fruit quality needs maximum control of growth and crop development, which is expected to be achieved with irrigation and nutrient

  5. Análise do resfriamento da solução nutritiva para cultivo hidropônico do morangueiro Nutrient solution cooling evaluation for hydroponic cultivation of strawberry plant

    Directory of Open Access Journals (Sweden)

    Luiz V. E. Villela Júnior

    2004-08-01

    Full Text Available Este trabalho teve como objetivo a produção hidropônica de morangos com resfriamento da solução nutritiva, em Jaboticabal - SP. O experimento foi conduzido no Setor de Plasticultura do Departamento de Engenharia Rural da FCAV/UNESP, Câmpus de Jaboticabal, em casa de vegetação coberta com filme de polietileno, sendo o transplantio realizado em 9-1-2002. Foram avaliadas duas variedades de morango: Campinas e "Sweet Charlie", cultivadas em sistema hidropônico tipo NFT, com ou sem resfriamento da solução nutritiva. A solução nutritiva resfriada foi mantida à temperatura de aproximadamente 12 ºC, por meio de um trocador de calor. A variedade "Sweet Charlie" apresentou melhores resultados para peso médio dos pseudofrutos, diâmetro médio longitudinal, diâmetro médio transversal, número médio de pseudofrutos e produtividade. O resfriamento da solução nutritiva conferiu maior número de pseudofrutos colhidos, maior produtividade e maior teor de sólidos solúveis totais aos pseudofrutos da variedade "Sweet Charlie". No entanto, o resfriamento da solução nutritiva não causou efeitos sobre a variedade Campinas.This work had as its major aim the hydroponic production of strawberries with the cooling of the nutrient solution, in Jaboticabal - SP - Brazil. The experiment was conducted in a covered greenhouse with a plastic film and seed transplantation achieved on January 9, 2002. Two varieties of strawberries were evaluated: Campinas and Sweet Charlie, both cultivated under the hydroponic system NFT type with or without cooling the nutrient solution. The cooling of the nutrient solution at about 12 °C was in a heating exchange device. The Sweet Charlie variety presented the best results for both the average weight and number of pseudofruit, longitudinal average diameter, cross average diameter, average number of pseudofruit and productivity. The cooling of the nutrient solution confered greater number of pseudofruit collected and

  6. Physiological indexese macro- and micronutrients in plant tissue and essential oil of Mentha piperita L. grown in nutrient solution with variation in N, P, K and Mg levels

    Directory of Open Access Journals (Sweden)

    E.F.S. David

    2014-03-01

    Full Text Available Mentha piperita L. is an aromatic and medicinal species of the family Lamiaceae, known as mint or peppermint, and its leaves and branches produce essential oil rich in menthol. This study aimed to evaluate physiological indexes, macro- and micronutrients inthe shootsand essential oil of Mentha piperita L. grown in nutrient solution number 2 of Hoagland and Arnon (1950 with different N, P, K and Mg levels. Shoot length, dry mass of the different organs, total dry mass, leaf area, essential oil yield and composition, and macronutrient (N, P, K, Mg, Ca, S and micronutrient (Mn, Cu, Fe, Zn contents in the shoot were evaluated. Plants treated with 65%N/50%P/25%K/100%Mg had a tendency towards longer shoot, greaterroot and leaf blade dry masses, higher essential oil yield, higher menthol levels and lower menthone levels. The results showed that Mentha can be grown in nutrient solution by reducing 65% N, 50% P, 25% K and 100% Mg. This solution had better development compared to the other tested treatments. Therefore,we recommendMentha piperita L. to be grown with such nutrient levels.

  7. Nutrient Film Technique (NFT Hydroponic Monitoring System

    Directory of Open Access Journals (Sweden)

    Helmy Helmy

    2016-10-01

    Full Text Available Plant cultivation using hydroponic is very popular today. Nutrient Film Technique (NFT hydroponic system is commonly used by people. It can be applied indoor or outdoor. Plants in this systemneed nutrient solution to grow well. pH, TDS and temperature of the nutrient solution must be check to ensure plant gets sufficient nutrients. This research aims todevelop monitoring system of NFT hydroponic. Farmer will be able to monitor pH, TDS and temperature online. It will ease farmer to decide which plant is suitable to be cultivated and time to boost growth.Delay of the system will be measured to know system performance. Result shows that pH is directly proportional with TDS. Temperature value has no correlation with pH and TDS. System has highest delay during daylight and afternoon but it will decline in the night and morning. Average of delay in the morning is 11 s, 28.5 s in daylight, 32 s in the afternoon and 17.5 s in the night.

  8. Coastal Acidification as Nutrients Over Enrichment Impact: A Case Study in Ambon Bay, Indonesia

    Directory of Open Access Journals (Sweden)

    Idha Yulia Ikhsani

    2017-05-01

    Full Text Available Ambon Bay is a silled bay on Ambon Island consisting of two regions, Inner Ambon Bay (IAB and Outer Ambon Bay (OAB that are separated by shallow sill. Ambon bay and its surrounding have economically important ecosystem since the utilization for many activities. The bay is affected by anthropogenic impacts associated with urbanization, climate change, and nutrients over enrichment. The “deep water-rich nutrients” from Banda Sea that enter the bay during Southeast monsoon also contribute to this enrichment as well as the nutrients transport from the land. The high concentration of nutrients increases carbon dioxide level and promotes acidifications. There are literatures about nutrients over enrichment in Ambon Bay, however, little is known about coastal acidification as nutrients over enrichment impact. In order to study the effect of nutrients distribution on the acidity of Ambon Bay, the researchers measured pH and concentrations of nutrients {nitrate + nitrite (N+N and Soluble Reactive Phosphate (SRP} from water samples collected in 7 stations on both IAB and OAB during Southeast monsoon. The results showed that in surface water, nutrients concentrations is increased from May to June due to the “deep water flushing” occurrence on May and increased precipitations from May to June. From July to August, the nutrients concentrations on surface layer decreased, due to the decreased precipitations. In column and bottom water, the nutrients concentrations were increased from May to August. While the acidity have reverse pattern from the nutrients, when nutrient concentrations increased the acidity was decreased. From correlation test, pH was not significantly correlated with the concentrations of nutrients on surface water, but showed significantly correlated on column and bottom water. The results indicated that the distribution of nutrients on column and bottom water might be an important environmental factor affecting the acidification of

  9. Effect of Nitrogen Nutritional Stress on some Mineral Nutrients and Photosynthetic Apparatus of Zea mays L. and Vigna unguiculata L.

    Directory of Open Access Journals (Sweden)

    Akinbode Foluso OLOGUNDUDU

    2013-08-01

    Full Text Available The study investigated the responses of maize (Zea mays L. and cowpea (Vigna unguiculata L. Walp. seedlings metabolic activities and photosynthetic apparatus to nitrogen nutritional stress. Germination of seeds was done using treated sand in sixty plastic pots and the seedlings were divided into four nutrient regimes. A group of the seedlings was nutrient stressed by administering 200 ml of complete nutrient solution minus nitrogen (-N while the other groups were fed with five times (X5N and ten times (X10N the optimal concentration of nitrogen and the last regime was fed with full nutrient solution (FN. The photosynthetic parameters studied included chlorophylls ‘a’ and ‘b’ respectively; carotenes and xanthophyll while the mineral elements investigated include potassium, calcium and magnesium. The result of the growth analysis showed that nitrogen deficiency promotes an increase in the content of abscisic acid (ABA, causing stomatal closure and a reduction in photosynthesis. This explains the higher rate of leaf abscission in -N plants. A comparison of calcium ion and magnesium ion concentrations in both optimal and stressed conditions reveals that the two ions show antagonism in uptake. There is a correlation between nitrogen and magnesium accumulation as magnesium ion plays a vital role in chlorophyll biosynthesis, protein synthesis and photosynthesis. The pattern of accumulation of photosynthetic apparatus in both maize and cowpea follow a similar pattern. Chlorophyll a dictated the growth pattern of other photosynthetic apparatus in both Zea mays and Vigna unguiculata.

  10. Effects of arsenic on concentration and distribution of nutrients in the fronds of the arsenic hyperaccumulator Pteris vittata L

    International Nuclear Information System (INIS)

    Tu Cong; Ma, Lena Q.

    2005-01-01

    Pteris vittata was the first terrestrial plant known to hyperaccumulate arsenic (As). However, it is unclear how As hyperaccumulation influences nutrient uptake by this plant. P. vittata fern was grown in soil spiked with 0-500 mg As kg -1 in the greenhouse for 24 weeks. The concentrations of essential macro- (P, K, Ca, and Mg) and micro- (Fe, Mn, Cu, Zn, B and Mo) elements in the fronds of different age were examined. Both macro- and micronutrients in the fronds were found to be within the normal concentration ranges for non-hyperaccumulators. However, As hyperaccumulation did influence the elemental distribution among fronds of different age of P. vittata. Arsenic-induced P and K enhancements in the fronds contributed to the As-induced growth stimulation at low As levels. The frond P/As molar ratios of 1.0 can be used as the threshold value for normal growth of P. vittata. Potassium may function as a counter-cation for As in the fronds as shown by the As-induced K increases in the fronds. The present findings not only demonstrate that P. vittata has the ability to maintain adequate concentrations of essential nutrients while hyperaccumulating As from the soil, but also have implications for soil management (fertilization in particular) of P. vittata in As phytoextraction practice

  11. Spatial and temporal shifts in gross primary productivity, respiration, and nutrient concentrations in urban streams impacted by wastewater treatment plant effluent

    Science.gov (United States)

    Ledford, S. H.; Toran, L.

    2017-12-01

    Impacts of wastewater treatment plant effluent on nutrient retention and stream productivity are highly varied. The working theory has been that large pulses of nutrients from plants may hinder in-stream nutrient retention. We evaluated nitrate, total dissolved phosphorus, and dissolved oxygen in Wissahickon Creek, an urban third-order stream in Montgomery and Philadelphia counties, PA, that receives effluent from four wastewater treatment plants. Wastewater treatment plant effluent had nitrate concentrations of 15-30 mg N/L and total dissolved phosphorus of 0.3 to 1.8 mg/L. Seasonal longitudinal water quality samples showed nitrate concentrations were highest in the fall, peaking at 22 mg N/L, due to low baseflow, but total dissolved phosphorous concentrations were highest in the spring, reaching 0.6 mg/L. Diurnal dissolved oxygen patterns above and below one of the treatment plants provided estimates of gross primary productivity (GPP) and ecosystem respiration (ER). A site 1 km below effluent discharge had higher GPP in April (80 g O2 m-2 d-1) than the site above the plant (28 g O2 m-2 d-1). The pulse in productivity did not continue downstream, as the site 3 km below the plant had GPP of only 12 g O2 m-2 d-1. Productivity fell in June to 1-2 g O2 m-2 d-1 and the differences in productivity above and below plants were minimal. Ecosystem respiration followed a similar pattern in April, increasing from -17 g O2 m-2 d-1 above the plant to -47 g O2 m-2 d-1 1 km below the plant, then decreasing to -8 g O2 m-2 d-1 3 km below the plant. Respiration dropped to -3 g O2 m-2 d-1 above the plant in June but only fell to -9 to -10 g O2 m-2 d-1 at the two downstream sites. These findings indicate that large nutrient pulses from wastewater treatment plants spur productivity and respiration, but that these increases may be strongly seasonally dependent. Examining in-stream productivity and respiration is critical in wastewater impacted streams to understanding the seasonal and

  12. Alkali solution extraction of rice residue protein isolates: Influence of alkali concentration on protein functional, structural properties and lysinoalanine formation.

    Science.gov (United States)

    Hou, Furong; Ding, Wenhui; Qu, Wenjuan; Oladejo, Ayobami Olayemi; Xiong, Feng; Zhang, Weiwei; He, Ronghai; Ma, Haile

    2017-03-01

    This study evaluated the nutrient property and safety of the rice residue protein isolates (RRPI) product (extracted by different alkali concentrations) by exploring the protein functional, structural properties and lysinoalanine (LAL) formation. The results showed that with the rising of alkali concentration from 0.03M to 0.15M, the solubility, emulsifying and foaming properties of RRPI increased at first and then descended. When the alkali concentration was greater than 0.03M, the RRPI surface hydrophobicity decreased and the content of thiol and disulfide bond, Lys and Cys significantly reduced. By the analysis of HPLC, the content of LAL rose up from 276.08 to 15,198.07mg/kg and decreased to 1340.98mg/kg crude protein when the alkali concentration increased from 0.03 to 0.09M and until to 0.15M. These results indicated that RRPI alkaline extraction concentration above 0.03M may cause severe nutrient or safety problems of protein. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Radiolysis of concentrated solutions. 2. Pulse and #betta#-radiolysis studies of direct and indirect effects in lithium iodide solutions

    International Nuclear Information System (INIS)

    Hadjadj, A.; Julien, R.; Pucheault, J.; Ferradini, C.; Hickel, B.

    1982-01-01

    In the preceding study of the radiolysis of concentrated aqueous LiCl solutions, one of the hypotheses used to explain the apparent inefficacy of Cl 2- formation by the direct effect was that molecular chlorine, not detectable by spectrophotometry, could be formed during the early stages of water radiolysis. Such an hypothesis is confirmed here for pulse and #betta#-radiolysis of concentrated aqueous neutral LiI solutions. Indeed, it is shown that, 10 ns after the pulse, molecular iodine, detected as I 3- , is formed with a yield that increases with the LiI concentration. The experimental results yields values of 4.8 and 7.3 respectively for the indirect and direct effects of total oxidation G/sub I 2- / + 2G/sub I 3- /. This last high value is discussed

  14. Nutrient removal from swine lagoon effluent by duckweed

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, B.A.; Cheng, J.; Classen, J.; Stomp, A.M.

    2000-04-01

    Three duckweed geographic isolates were grown on varying concentrations of swine lagoon effluent in a greenhouse to determine their ability to remove nutrients from the effluent. Duckweed biomass was harvested every other day over a 12-day period. Duckweed biomass production, nutrient loss from the swine lagoon effluent, and nutrient content of duckweed biomass were used to identify effluent concentrations/geographic isolate combinations that are effective in terms of nutrient utilization from swine lagoon effluent and production of healthy duckweed biomass. When Lemna minor geographic isolate 8627 was grown on 50% swine lagoon effluent, respective losses of TKN, NH{sub 3}-N, TP, OPO{sub 4}-P, TOC, K, Cu, and Zn were 83, 100, 49, 31, 68, 21, 28 and 67%.

  15. Intragastric nutrient infusion reduces motivation for food in male and female rats.

    Science.gov (United States)

    Maske, Calyn B; Loney, Gregory C; Lilly, Nicole; Terrill, Sarah J; Williams, Diana L

    2018-03-13

    The idea that gut-derived satiation signals influence food reward has recently gained traction, but this hypothesis is largely based on studies focused on neural circuitry, not the peripherally released signals. Here, we directly tested the hypothesis that intragastric (IG) nutrient infusion can suppress motivation for food. In a series of experiments, IG sucrose infusion (15 kcal) significantly and reliably reduced operant responding for a sucrose reward on a progressive ratio (PR) schedule. Moreover, food deprivation for 24 h before the test session did not prevent the suppressive effect of nutrients. The suppressive effect of IG sucrose on fixed ratio 5 (FR5) operant responding was also assessed as a comparison. The effect of IG nutrients to reduce motivation was not limited to sucrose; IG Ensure infusion (9.3 kcal) also significantly reduced PR operant responding for sucrose pellets. To verify that these effects are not secondary to the osmotic challenge of concentrated nutrients, we tested IG infusion of non-caloric saline solutions equiosmolar to 40% sucrose or Ensure, and found no effect. Finally, we focused on glucagon-like peptide 1 (GLP-1) and cholecystokinin (CCK) as candidate mediators for the effect of IG nutrients. Pretreatment with Exendin-9, a GLP-1R antagonist, delivered IP, significantly attenuated the ability of IG nutrients to suppress PR responding and breakpoint in males, but not females, whereas pretreatment with Devazepide, a CCKA receptor antagonist, failed to do so in both sexes. Together, these data support the idea that nutrient-induced satiation signals influence food reward, and may implicate GLP-1 in this process.

  16. Rice grown in nutrient solution with doses of manganese and silicon Arroz cultivado em solução nutritiva com doses de manganês e silício

    Directory of Open Access Journals (Sweden)

    Luiz Antônio Zanão Júnior

    2010-10-01

    Full Text Available Although silicon is not recognized as a nutrient, it may benefit rice plants and may alleviate the Mn toxicity in some plant species. The dry matter yield (root, leaf, sheaths and leaf blade and plant architecture (angle of leaf insertion and leaf arc were evaluated in rice plants grown in nutrient solutions with three Mn doses, with and without Si addition. The treatments were arranged in a 2 x 3 factorial [with and without (2 mmol L-1 Si; three Mn doses (0.5; 2.5 and 10 µmol L-1], in a randomized block design with 4 replications. The experimental unit was a 4 L plastic vase with 4 rice (Metica-1 cultivar plants. Thirty nine days after keeping the seedlings in the nutrient solution the plant dry matter yield was determined; the angle of leaf insertion in the sheath and the leaf arc were measured; and the Si and Mn concentrations in roots, sheaths and leaves were determined. The analysis of variance (F test at 5 and 1 % levels and the regression analysis (for testing plant response to Mn with the Si treatments were performed. The Si added to the nutrient solution increased the dry matter yield of roots, sheaths and leaf blades and also decreased the angle of leaf blade insertion into the sheath and the foliar arc in the rice plant. Additionally, it ameliorated the rice plant architecture which allowed an increase in the dry matter yield. Similarly, the addition of Mn to the solution improved the architecture of the rice plants with gain in dry matter yield. As Si was added to the nutrient solution, the concentration of Mn in leaves decreased and in roots increased thus alleviating the toxic effects of Mn on the plants.O silício destaca-se por exercer vários benefícios para a cultura do arroz, apesar de não ser considerado um nutriente. Um desses benefícios é que ele pode amenizar a toxidez causada por Mn em algumas espécies de plantas. Objetivou-se com este trabalho avaliar a produção de matéria seca (raízes, bainhas e limbo foliar e

  17. Environmental farm accounting: the case of the Dutch nutrients accounting system.

    NARCIS (Netherlands)

    Breembroek, J.A.; Koole, B.; Poppe, K.J.; Wossink, G.A.A.

    1996-01-01

    In the Netherlands bookkeeping of inputs and outputs at the level of individual farms has been selected as a new solution to control nutrient use and to tax nutrient surpluses in agriculture. At the same time, nutrient accounting presents important management information. This paper presents a

  18. Two-dimensional analytical solutions for chemical transport in aquifers. Part 1. Simplified solutions for sources with constant concentration. Part 2. Exact solutions for sources with constant flux rate

    International Nuclear Information System (INIS)

    Shan, C.; Javandel, I.

    1996-05-01

    Analytical solutions are developed for modeling solute transport in a vertical section of a homogeneous aquifer. Part 1 of the series presents a simplified analytical solution for cases in which a constant-concentration source is located at the top (or the bottom) of the aquifer. The following transport mechanisms have been considered: advection (in the horizontal direction), transverse dispersion (in the vertical direction), adsorption, and biodegradation. In the simplified solution, however, longitudinal dispersion is assumed to be relatively insignificant with respect to advection, and has been neglected. Example calculations are given to show the movement of the contamination front, the development of concentration profiles, the mass transfer rate, and an application to determine the vertical dispersivity. The analytical solution developed in this study can be a useful tool in designing an appropriate monitoring system and an effective groundwater remediation method

  19. Hyperspectral remote sensing techniques for grass nutrient estimations in savannah ecosystems

    CSIR Research Space (South Africa)

    Ramoelo, Abel

    2010-03-01

    Full Text Available Information on the distribution of grass quality (nutrient concentration) is crucial in understanding rangeland vitality and facilitates effective management of wildlife and livestock. The spatial distribution of grass nutrient concentration occurs...

  20. Lipid-based nutrient supplements do not affect efavirenz but lower plasma nevirapine concentrations in Ethiopian adult HIV patients

    DEFF Research Database (Denmark)

    Abdissa, A; Olsen, Mette Frahm; Yilma, D

    2015-01-01

    OBJECTIVES: Lipid-based nutrient supplements (LNSs) are increasingly used in HIV programmes in resource-limited settings. However, the possible effects of LNSs on the plasma concentrations of antiretroviral drugs have not been assessed. Here, we aimed to assess the effects of LNSs on plasma...... efavirenz and nevirapine trough concentrations in Ethiopian adult HIV-infected patients. METHODS: The effects of LNSs were studied in adults initiating antiretroviral therapy (ART) in a randomized trial. Patients with body mass index (BMI) > 17 kg/m(2) (n = 282) received daily supplementation of an LNS.......9; -0.9 μg/mL; P = 0.01), respectively, compared with the group not receiving supplements. There were no differences between groups with respect to efavirenz plasma concentrations. The CYP2B6 516 G>T polymorphism was associated with a 5 μg/mL higher plasma efavirenz concentration compared with the wild...

  1. Roots, plant production and nutrient use efficiency

    NARCIS (Netherlands)

    Willigen, de P.; Noordwijk, van M.

    1987-01-01

    The role of roots in obtaining high crop production levels as well as a high nutrient use efficiency is discussed. Mathematical models of diffusion and massflow of solutes towards roots are developed for a constant daily uptake requirement. Analytical solutions are given for simple and more

  2. Interaction of Celestine Concentrate and Reagent Grade SrSO4 with Oxalate Solutions

    Directory of Open Access Journals (Sweden)

    Abdullah Obut

    2012-12-01

    Full Text Available The interaction of reagent grade strontium sulphate and celestine concentrate with aqueous solutions of oxalic acid, sodiumoxalate and ammonium oxalate for the production of strontium carbonate were investigated for different oxalate compound:SrSO4 moleratios and reaction times using x-ray diffraction analysis and dissolution tests. Under the same experimental conditions, it was foundthat aqueous oxalic acid and sodium oxalate solutions had no or little effect on reagent grade strontium sulphate or celestineconcentrate, but aqueous ammonium oxalate solution converted them into strontium oxalate hydrate. Strontium carbonate was obtainedat conversion ratios of 74.7% for the celestine concentrate and 84.6 % for the reagent grade strontium sulphate by the decompositionof the obtained strontium oxalate hydrate at 600 °C under air atmosphere.

  3. Solution-processed organic thermoelectric materials exhibiting doping-concentration-dependent polarity.

    Science.gov (United States)

    Hwang, Sunbin; Potscavage, William J; Yang, Yu Seok; Park, In Seob; Matsushima, Toshinori; Adachi, Chihaya

    2016-10-26

    Recent progress in conducting polymer-based organic thermoelectric generators (OTEGs) has resulted in high performance due to high Seebeck coefficient, high electrical conductivity (σ), and low thermal conductivity obtained by chemically controlling the materials's redox levels. In addition to improving the properties of individual OTEGs to obtain high performance, the development of solution processes for the fabrication of OTEG modules is necessary to realize large thermoelectric voltage and low-cost mass production. However, the scarcity of good candidates for soluble organic n-type materials limits the use of π-leg module structures consisting of complementary elements of p- and n-type materials because of unbalanced transport coefficients that lead to power losses. In particular, the extremely low σ of n-type materials compared with that of p-type materials is a serious challenge. In this study, poly(pyridinium phenylene) (P(PymPh)) was tested as an n-type semiconductor in solution-processed OTEGs, and the carrier density was controlled by a solution-based chemical doping process using the dopant sodium naphthalenide, a well-known reductant. The electronic structures and doping mechanism of P(PymPh) were explored based on the changes in UV-Vis-IR absorption, ultraviolet photoelectron, and X-ray photoelectron spectra. By controlling the dopant concentration, we demonstrate a maximum n-type power factor of 0.81 μW m -1 K -2 with high σ, and at higher doping concentrations, a switch from n-type to p-type TE operation. This is one of the first cases of a switch in polarity just by increasing the concentration of the reductant and may open a new route for simplified fabrication of complementary organic layers.

  4. Increase The Sugar Concentration of The Solution Sugar by Reverse Osmotic Membrane

    Science.gov (United States)

    Redjeki, S.; Hapsari, N.; Iriani

    2018-01-01

    Sugar is one of the basic needs of people and food and drink industry. As technology advances and the demand for efficient usage of sugar rises, crystal sugar is seen as less advantageous than liquid sugar. If sugar is always dissolved in water before use, then it will be more efficient and practical for consumers to use sugar in liquid form than in crystal form. Other than that, liquid sugar is also attractive to consumers because it is economical, hygienic, instantly soluble in hot and cold water, fresher and longer-lasting, able to thicken and enrich the texture of foods and drinks, and functions as sweetener, syrup, and flavor enhancer. Liquid sugar is also more beneficial for sugar producers because of simpler production process, cheaper production cost, and similar yield with no extra cost. In sugar production, separation process is found in most of its stages and therefore the use of membrane technology for separating solute and water content has a good potential. In this research, water content reduction of sugar solution was done in order to increase the sugar concentration of the solution. The parameters of this research were 4%, 5%, and 6% starting concentration of sugar solution; 20, 40, and 60 minutes of process time; and 85 and 60 PSI ΔP. The best result was acquired on 4% starting concentration, 60 PSI ΔP, and 60 minutes process time.

  5. Temporal Changes in the Spatial Variability of Soil Nutrients

    Energy Technology Data Exchange (ETDEWEB)

    Hoskinson, Reed Louis; Hess, John Richard; Alessi, Randolph Samuel

    1999-07-01

    This paper reports the temporal changes in the spatial variability of soil nutrient concentrations across a field during the growing season, over a four-year period. This study is part of the Site-Specific Technologies for Agriculture (SST4Ag) precision farming research project at the INEEL. Uniform fertilization did not produce a uniform increase in fertility. During the growing season, several of the nutrients and micronutrients showed increases in concentration although no additional fertilization had occurred. Potato plant uptake did not explain all of these changes. Some soil micronutrient concentrations increased above levels considered detrimental to potatoes, but the plants did not show the effects in reduced yield. All the nutrients measured changed between the last sampling in the fall and the first sampling the next spring prior to fertilization. The soil microbial community may play a major role in the temporal changes in the spatial variability of soil nutrient concentrations. These temporal changes suggest potential impact when determining fertilizer recommendations, and when evaluating the results of spatially varying fertilizer application.

  6. Leaf habit and woodiness regulate different leaf economy traits at a given nutrient supply.

    Science.gov (United States)

    Ordoñez, Jenny C; van Bodegom, Peter M; Witte, Jan-Philip M; Bartholomeus, Ruud P; van Dobben, Han F; Aerts, Rien

    2010-11-01

    The large variation in the relationships between environmental factors and plant traits observed in natural communities exemplifies the alternative solutions that plants have developed in response to the same environmental limitations. Qualitative attributes, such as growth form, woodiness, and leaf habit can be used to approximate these alternative solutions. Here, we quantified the extent to which these attributes affect leaf trait values at a given resource supply level, using measured plant traits from 105 different species (254 observations) distributed across 50 sites in mesic to wet plant communities in The Netherlands. For each site, soil total N, soil total P, and water supply estimates were obtained by field measurements and modeling. Effects of growth forms, woodiness, and leaf habit on relations between leaf traits (SLA, specific leaf area; LNC, leaf nitrogen concentration; and LPC, leaf phosphorus concentration) vs. nutrient and water supply were quantified using maximum-likelihood methods and Bonferroni post hoc tests. The qualitative attributes explained 8-23% of the variance within sites in leaf traits vs. soil fertility relationships, and therefore they can potentially be used to make better predictions of global patterns of leaf traits in relation to nutrient supply. However, at a given soil fertility, the strength of the effect of each qualitative attribute was not the same for all leaf traits. These differences may imply a differential regulation of the leaf economy traits at a given nutrient supply, in which SLA and LPC seem to be regulated in accordance to changes in plant size and architecture while LNC seems to be primarily regulated at the leaf level by factors related to leaf longevity.

  7. Condutividade elétrica da solução nutritiva e acúmulo de macro e micronutrientes no cultivo de crisântemo Electrical conductivity of nutrient solution on growth and nutrient accumulation in chrysanthemum plants

    Directory of Open Access Journals (Sweden)

    Poliana Rocha D'Almeida Mota

    2013-03-01

    Full Text Available A análise de crescimento com base no acúmulo de fitomassa e na marcha de absorção de nutrientes são importantes para determinar as épocas da maior demanda nutricional, de modo a programar a fertirrigação. Assim, esta pesquisa tem como objetivo determinar o crescimento e o acúmulo de nutrientes em plantas de crisântemo desenvolvidas em diferentes níveis de condutividade elétrica (CE da solução nutritiva. Realizou-se experimento em casa de vegetação, utilizando o delineamento de blocos casualizados com cinco tratamentos e quatro repetições. Os tratamentos corresponderam aos níveis de CE da solução aplicada, com valores de 1,42; 1,65; 1,89; 2,13 e 2,36 dS m¹(fase vegetativa e 1,71; 1,97; 2,28; 2,57 e 2,85 dS m¹(fase de botão. Após o enraizamento das estacas, determinou-se a fitomassa seca da parte aérea e realizou-se a análise química dos macronutrientes e micronutrientes a cada quatorze dias. Os nutrientes tiveram a seguinte ordem de absorção: K>N>Ca>P>Mg>S (1425, 892, 184, 150, 110 e 59 mg planta¹ e Fe>Zn>B>Mn>Cu (2254, 2219, 1725, 1287,210 µg planta¹. Grande parte dos nutrientes tem seu teor aumentado com a elevação do nível da CE da solução, sem que haja efeito salino até a CE de 2,85 dS m¹The study of growth and uptake of nutrients is important to determine the times of increased demand in order to schedule the fertigation. The present research was developed with the objective of evaluating the effects of different levels of electrical conductivity on growth and accumulation of nutrients in chrysanthemum plants under greenhouse conditions. The electri- cal conductivity levels on the applied solution were 1. 42, 1. 65, 1. 89, 2. 13 and 2. 36 dS m¹(bud vegetative stage; 1. 71, 1. 97, 2. 28, 2. 57 and 2. 85 dS m¹(bud stage. The dry mass of the aerial portion of the plant and the contents of macronutrients and micronutrients were determined every 14 days. The nutrient accumulation in chrysanthemum plant

  8. Condutividade elétrica da solução nutritiva e acúmulo de macro e micronutrientes no cultivo de crisântemo Electrical conductivity of nutrient solution on growth and nutrient accumulation in chrysanthemum plants

    Directory of Open Access Journals (Sweden)

    Poliana Rocha D'Almeida Mota

    2013-01-01

    Full Text Available A análise de crescimento com base no acúmulo de fitomassa e na marcha de absorção de nutrientes são importantes para determinar as épocas da maior demanda nutricional, de modo a programar a fertirrigação. Assim, esta pesquisa tem como objetivo determinar o crescimento e o acúmulo de nutrientes em plantas de crisântemo desenvolvidas em diferentes níveis de condutividade elétrica (CE da solução nutritiva. Realizou-se experimento em casa de vegetação, utilizando o delineamento de blocos casualizados com cinco tratamentos e quatro repetições. Os tratamentos corresponderam aos níveis de CE da solução aplicada, com valores de 1,42; 1,65; 1,89; 2,13 e 2,36 dS m¹(fase vegetativa e 1,71; 1,97; 2,28; 2,57 e 2,85 dS m¹(fase de botão. Após o enraizamento das estacas, determinou-se a fitomassa seca da parte aérea e realizou-se a análise química dos macronutrientes e micronutrientes a cada quatorze dias. Os nutrientes tiveram a seguinte ordem de absorção: K>N>Ca>P>Mg>S (1425, 892, 184, 150, 110 e 59 mg planta¹ e Fe>Zn>B>Mn>Cu (2254, 2219, 1725, 1287,210 µg planta¹. Grande parte dos nutrientes tem seu teor aumentado com a elevação do nível da CE da solução, sem que haja efeito salino até a CE de 2,85 dS m¹The study of growth and uptake of nutrients is important to determine the times of increased demand in order to schedule the fertigation. The present research was developed with the objective of evaluating the effects of different levels of electrical conductivity on growth and accumulation of nutrients in chrysanthemum plants under greenhouse conditions. The electri- cal conductivity levels on the applied solution were 1. 42, 1. 65, 1. 89, 2. 13 and 2. 36 dS m¹(bud vegetative stage; 1. 71, 1. 97, 2. 28, 2. 57 and 2. 85 dS m¹(bud stage. The dry mass of the aerial portion of the plant and the contents of macronutrients and micronutrients were determined every 14 days. The nutrient accumulation in chrysanthemum plant

  9. Recrystallization of freezable bound water in aqueous solutions of medium concentrations

    Institute of Scientific and Technical Information of China (English)

    赵立山; 潘礼庆; 纪爱玲; 曹则贤; 王强

    2016-01-01

    For aqueous solutions with freezable bound water, vitrification and recrystallization are mingled, which brings diffi-culty to application and misleads the interpretation of relevant experiments. Here, we report a quantification scheme for the freezable bound water based on the water-content dependence of glass transition temperature, by which also the concentra-tion range for the solutions that may undergo recrystallization finds a clear definition. Furthermore, we find that depending on the amount of the freezable bound water, different temperature protocols should be devised to achieve a complete recrys-tallization. Our results may be helpful for understanding the dynamics of supercooled aqueous solutions and for improving their manipulation in various industries.

  10. Non-invasive optical detection of glucose in cell culture nutrient medium

    Science.gov (United States)

    Cote, Gerald L.

    1993-01-01

    The objective of the proposed research was to begin the development of a non-invasive optical sensor for measuring glucose concentration in the output medium of cell cultures grown in a unique NASA bioreactor referred to as an integrated rotating-wall vessel (IRWV). The input, a bovine serum based nutrient media, has a known glucose concentration. The cells within the bioreactor digest a portion of the glucose. Thus, the non-invasive optical sensor is needed to monitor the decrease in glucose due to cellular consumption since the critical parameters for sustained cellular productivity are glucose and pH. Previous glucose sensing techniques have used chemical reactions to quantify the glucose concentration. Chemical reactions, however, cannot provide for continuous, real time, non-invasive measurement as is required in this application. Our effort while in the fellowship program was focused on the design, optical setup, and testing of one bench top prototype non-invasive optical sensor using a mid-infrared absorption spectroscopy technique. Glucose has a fundamental vibrational absorption peak in the mid-infrared wavelength range at 9.6 micron. Preliminary absorption data using a CO2 laser were collected at this wavelength for water based glucose solutions at different concentrations and one bovine serum based nutrient medium (GTSF) with added glucose. The results showed near linear absorption responses for the glucose-in-water data with resolutions as high at 108 mg/dl and as low as 10 mg/dl. The nutrient medium had a resolution of 291 mg/dl. The variability of the results was due mainly to thermal and polarization drifts of the laser while the decrease in sensitivity to glucose in the nutrient medium was expected due to the increase in the number of confounders present in the nutrient medium. A multispectral approach needs to be used to compensate for these confounders. The CO2 laser used for these studies was wavelength tunable (9.2 to 10.8 micrometers), however

  11. Quantifying stream nutrient uptake from ambient to saturation with instantaneous tracer additions

    Science.gov (United States)

    Covino, T. P.; McGlynn, B. L.; McNamara, R.

    2009-12-01

    Stream nutrient tracer additions and spiraling metrics are frequently used to quantify stream ecosystem behavior. However, standard approaches limit our understanding of aquatic biogeochemistry. Specifically, the relationship between in-stream nutrient concentration and stream nutrient spiraling has not been characterized. The standard constant rate (steady-state) approach to stream spiraling parameter estimation, either through elevating nutrient concentration or adding isotopically labeled tracers (e.g. 15N), provides little information regarding the stream kinetic curve that represents the uptake-concentration relationship analogous to the Michaelis-Menten curve. These standard approaches provide single or a few data points and often focus on estimating ambient uptake under the conditions at the time of the experiment. Here we outline and demonstrate a new method using instantaneous nutrient additions and dynamic analyses of breakthrough curve (BTC) data to characterize the full relationship between spiraling metrics and nutrient concentration. We compare the results from these dynamic analyses to BTC-integrated, and standard steady-state approaches. Our results indicate good agreement between these three approaches but we highlight the advantages of our dynamic method. Specifically, our new dynamic method provides a cost-effective and efficient approach to: 1) characterize full concentration-spiraling metric curves; 2) estimate ambient spiraling metrics; 3) estimate Michaelis-Menten parameters maximum uptake (Umax) and the half-saturation constant (Km) from developed uptake-concentration kinetic curves, and; 4) measure dynamic nutrient spiraling in larger rivers where steady-state approaches are impractical.

  12. Seasonality of nutrients in leaves and fruits of apple trees

    Directory of Open Access Journals (Sweden)

    Nachtigall Gilmar Ribeiro

    2006-01-01

    Full Text Available The nutrient accumulation curves of apple trees are good indicators of plant nutrient demand for each developmental stage. They are also a useful tool to evaluate orchard nutritional status and to estimate the amount of soil nutrient removal. This research aimed at evaluating the seasonality of nutrients in commercial apple orchards during the agricultural years of 1999, 2000, and 2001. Therefore, apple tree leaves and fruits of three cultivars 'Gala', 'Golden Delicious' and 'Fuji' were weekly collected and evaluated for fresh and dry matter, fruit diameter and macronutrient (N, P, K, Ca and Mg and micronutrient (B, Cu, Fe, Mn, and Zn concentrations. Leaf and fruit sampling started one or two weeks after full bloom, depending on the cultivar, and ended at fruit harvest or four weeks later (in the case of leaf sampling. In general, leaf concentrations of N, P, K, Cu, and B decreased; Ca increased; and Mg, Fe, Mn, and Zn did vary significantly along the plant vegetative cycle. In fruits, the initial nutrient concentrations decreased quickly, undergoing slow and continuous decreases and then remaining almost constant until the end of fruit maturation, indicating nutrient dilution, once the total nutrient accumulation increased gradually with fruit growth. Potassium was the nutrient present in highest quantities in apple tree fruits and thus, the most removed from the soil.

  13. Physico-chemical stability of eribulin mesylate containing concentrate and ready-to-administer solutions.

    Science.gov (United States)

    Spindeldreier, Kirsten; Thiesen, Judith; Lipp, Hans-Peter; Krämer, Irene

    2014-06-01

    The aim of this study was to determine the stability of commercially available eribulin mesylate containing injection solution as well as diluted ready-to-administer solutions stored under refrigeration or at room temperature. Stability was studied by a novel developed stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) assay with ultraviolet detection (detection wavelength 200 nm). Triplicate test solutions of eribulin mesylate containing injection concentrate (0.5 mg/mL) and with 0.9% sodium chloride solution diluted ready-to-administer preparations (0.205 mg/mL eribulin mesylate in polypropylene (PP) syringes, 0.020 mg/mL eribulin mesylate in polypropylene/polyethylene (PE) bags) were stored protected from light either at room temperature (25) or under refrigeration (2-8). Samples were withdrawn on day 0 (initial), 1, 3, 5, 7, 14, 21 and 28 of storage and assayed. Physical stability was determined by measuring the pH value once a week and checking for visible precipitations or colour changes. The stability tests revealed that concentrations of eribulin mesylate remained unchanged over a period of 28 days irrespective of concentration, container material or storage temperature. Neither colour changes nor visible particles have been observed. The pH value varied slightly over time but remained in the stability favourable range of 5-9. Eribulin mesylate injection (0.5 mg/mL) is physico-chemically stable over a period of 28 days after first puncture of the vial. After dilution with 0.9% NaCl vehicle solution, ready-to-administer eribulin mesylate injection solutions (0.205 mg/mL in PP syringe) and infusion solutions (0.02 mg/mL in prefilled PP/PE bags) are physico-chemically stable for a period of at least four weeks either refrigerated or stored at room temperature. For microbiological reasons storage under refrigeration is recommended.

  14. Nutrient cycling and ecosystem metabolism in boreal streams of the Central Siberian Plateau

    Science.gov (United States)

    Diemer, L.; McDowell, W. H.; Prokushkin, A. S.

    2013-12-01

    Arctic boreal streams are undergoing considerable change in carbon and nutrient biogeochemistry due to degrading permafrost and increasing fire activity. Recent studies show that fire increases transport of inorganic solutes from the boreal landscape to arctic streams in some regions; couple this with expected greater labile dissolved organic carbon (DOC) from deepening active layers, enhanced biomass production, and increased annual precipitation and boreal streams may experience greater in-stream primary production and respiration in the coming century. Little is known about the spatial and temporal dynamics of inorganic nutrients in relation to C availability in headwater streams of a major Arctic region, the Central Siberian Plateau. Our preliminary data of Central Siberian headwater streams show NO3 and PO4 concentrations near or below detection limits (e.g. nine samples taken in spring from a small stream near the Russian settlement of Tura averaged 10 μg/L NO3-N and 9.7 μg/L PO4-P), and recent studies in Central Siberia suggest that bioavailable organic matter and inorganic nutrients such as NO3 will likely increase with climate warming. We examined the fate of nutrients in Central Siberian streams using Tracer for Spiraling Curve Characterization (TASCC) additions of NO3, NH4, and PO4 along with conservative tracer, NaCl, in spring at high and low discharges in streams underlain by continuous permafrost in Central Siberia. We also sampled two sites in spring every 2 hours overnight for 24 hours to document any diel patterns in DOC and inorganic nutrients. Our results thus far show that NO3 uptake length may be strongly correlated with DOC concentration (a function of fire activity). Preliminary results also show that despite high discharge and cold temperatures (4-8°C) in mid to late spring, there appears to be biological activity stimulating a diel signal for NO3 with maximum concentration corresponding to low light (11 PM). Investigating the primary

  15. Unusual concentration-dependent microscopic dynamics of dendrimers in aqueous solution

    International Nuclear Information System (INIS)

    Wong, Kaikin; Wu, Chin Ming; Lam, Hak Fai; Chathoth, Suresh M.

    2016-01-01

    Dendrimers are novel three-dimensional, hyperbranched globular nanopolymeric macromolecules. The nanoscopic size, narrow polydispersity index, excellent control over molecular structure, availability of multiple functional groups at the periphery, and cavities in the interior made them very attractive candidate for drug delivery. In this communication, we have studied the microscopic dynamics of tetra-acid and pentaerythritol glycidyl ether dendrimers dissolved in aqueous solution with different concentrations. The effects of concentration and temperature to their long-range diffusion process are investigated by dynamic light scattering. Experimental results show a huge variation in the translational diffusion coefficient for the two dendrimers samples. Besides, the dependence of diffusion coefficients on concentration is unusually different in these dendrimer samples. Although the diffusion process follows Arrhenius relation with the temperature in both systems, the activation energy for the diffusion process has a distinct concentration dependence.

  16. Unusual concentration-dependent microscopic dynamics of dendrimers in aqueous solution

    Science.gov (United States)

    Wong, Kaikin; Wu, Chin Ming; Lam, Hak Fai; Chathoth, Suresh M.

    2016-05-01

    Dendrimers are novel three-dimensional, hyperbranched globular nanopolymeric macromolecules. The nanoscopic size, narrow polydispersity index, excellent control over molecular structure, availability of multiple functional groups at the periphery, and cavities in the interior made them very attractive candidate for drug delivery. In this communication, we have studied the microscopic dynamics of tetra-acid and pentaerythritol glycidyl ether dendrimers dissolved in aqueous solution with different concentrations. The effects of concentration and temperature to their long-range diffusion process are investigated by dynamic light scattering. Experimental results show a huge variation in the translational diffusion coefficient for the two dendrimers samples. Besides, the dependence of diffusion coefficients on concentration is unusually different in these dendrimer samples. Although the diffusion process follows Arrhenius relation with the temperature in both systems, the activation energy for the diffusion process has a distinct concentration dependence.

  17. Unusual concentration-dependent microscopic dynamics of dendrimers in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Kaikin; Wu, Chin Ming; Lam, Hak Fai; Chathoth, Suresh M., E-mail: smavilac@cityu.edu.hk [City University of Hong Kong, Department of Physics and Materials Science (Hong Kong, People’s Republic of China) (China)

    2016-05-15

    Dendrimers are novel three-dimensional, hyperbranched globular nanopolymeric macromolecules. The nanoscopic size, narrow polydispersity index, excellent control over molecular structure, availability of multiple functional groups at the periphery, and cavities in the interior made them very attractive candidate for drug delivery. In this communication, we have studied the microscopic dynamics of tetra-acid and pentaerythritol glycidyl ether dendrimers dissolved in aqueous solution with different concentrations. The effects of concentration and temperature to their long-range diffusion process are investigated by dynamic light scattering. Experimental results show a huge variation in the translational diffusion coefficient for the two dendrimers samples. Besides, the dependence of diffusion coefficients on concentration is unusually different in these dendrimer samples. Although the diffusion process follows Arrhenius relation with the temperature in both systems, the activation energy for the diffusion process has a distinct concentration dependence.

  18. Nutrients versus emerging contaminants–Or a dynamic match between subsidy and stress effects on stream biofilms

    International Nuclear Information System (INIS)

    Aristi, I.; Casellas, M.; Elosegi, A.; Insa, S.; Petrovic, M.; Sabater, S.; Acuña, V.

    2016-01-01

    Freshwater ecosystems are threatened by multiple anthropogenic stressors, which might be differentiated into two types: those that reduce biological activity at all concentrations (toxic contaminants), and those that subsidize biological activity at low concentrations and reduce it at high concentrations (assimilable contaminants). When occurring in mixtures, these contaminants can have either antagonistic, neutral or synergistic effects; but little is known on their joint effects. We assessed the interaction effects of a mixture of assimilable and toxic contaminants on stream biofilms in a manipulative experiment using artificial streams, and following a factorial design with three nutrient levels (low, medium or high) and either presence or absence of a mixture of emerging contaminants (ciprofloxacin, erythromycin, diclofenac, methylparaben, and sulfamethoxazole). We measured biofilm biomass, basal fluorescence, gross primary production and community respiration. Our initial hypotheses were that biofilm biomass and activity would: increase with medium nutrient concentrations (subsidy effect), but decrease with high nutrient concentrations (stress effect) (i); decrease with emerging contaminants, with the minimum decrease at medium nutrient concentrations (antagonistic interaction between nutrients subsidy and stress by emerging contaminants) and the maximum decrease at high nutrient concentrations (synergistic interaction between nutrients and emerging contaminants stress) (ii). All the measured variables responded linearly to the available nutrients, with no toxic effect at high nutrient concentrations. Emerging contaminants only caused weak toxic effects in some of the measured variables, and only after 3–4 weeks of exposure. Therefore, only antagonistic interactions were observed between nutrients and emerging contaminants, as medium and high nutrient concentrations partly compensated the harmful effects of emerging contaminants during the first weeks of the

  19. Lead phytotoxicity in soils and nutrient solutions is related to lead induced phosphorus deficiency

    International Nuclear Information System (INIS)

    Cheyns, Karlien; Peeters, Sofie; Delcourt, Dorien; Smolders, Erik

    2012-01-01

    This study was set up to relate lead (Pb) bioavailability with its toxicity to plants in soils. Tomato and barley seedlings were grown in six different PbCl 2 spiked soils (pH: 4.7–7.4; eCEC: 4.2–41.7 cmol c /kg). Soils were leached and pH corrected after spiking to exclude confounding factors. Plant growth was halved at 1600–6500 mg Pb/kg soil for tomato and at 1900–8300 mg Pb/kg soil for barley. These soil Pb threshold were unrelated to soil pH, organic carbon, texture or eCEC and neither soil solution Pb nor Pb 2+ ion activity adequately explained Pb toxicity among soils. Shoot phosphorus (P) concentrations significantly decreased with increasing soil Pb concentrations. Tomato grown in hydroponics at either varying P supply or at increasing Pb (equal initial P) illustrated that shoot P explained growth response in both scenarios. The results suggest that Pb toxicity is partially related to Pb induced P deficiency, likely due to lead phosphate precipitation. - Highlights: ► Tomato and barley shoot growth was affected by Pb toxicity in six different soils. ► Soil properties did not explain differences in plant Pb toxicity among soils. ► Neither soil solution Pb nor Pb 2+ ion activity explained Pb toxicity among soils. ► Shoot phosphorus concentration decreased with increasing soil Pb concentrations. ► Lead induced a P deficiency in plants, likely due to lead phosphate precipitation. - Soil properties did not explain differences in plant lead toxicity among different soils. Shoot phosphorus concentration decreased with increasing soil lead concentrations.

  20. Soil nutrient assessment for urban ecosystems in Hubei, China.

    Directory of Open Access Journals (Sweden)

    Zhi-Guo Li

    Full Text Available Recent urban landscape vegetation surveys conducted in many cities in China identified numerous plant nutrient deficiencies, especially in newly developed cities. Soil nutrients and soil nutrient management in the cities of Hubei province have not received adequate attention to date. The aims of this study were to characterize the available nutrients of urban soils from nine cities in Hubei province, China, and to assess how soil nutrient status is related to land use type and topography. Soil nutrients were measured in 405 sites from 1,215 soil samples collected from four land use types (park, institutional [including government building grounds, municipal party grounds, university grounds, and garden city institutes], residential, and roadside verges and three topographies (mountainous [142-425 m a.s.l], hilly [66-112 m a.s.l], and plain [26-30 m a.s.l]. Chemical analyses showed that urban soils in Hubei had high pH and lower soil organic matter, available nitrogen (N, available phosphorus (P, and available boron (B concentrations than natural soils. Nutrient concentrations were significantly different among land use types, with the roadside and residential areas having greater concentrations of calcium (Ca, sulfur (S, copper (Cu, manganese (Mn, and zinc (Zn that were not deficient against the recommended ranges. Topographic comparisons showed statistically significant effects for 8 of the 11 chemical variables (p < 0.05. Concentrations of N, Ca, Mg, S, Cu, and Mn in plain cities were greater than those in mountainous cities and show a negative correlation with city elevation. These results provide data on urban soils characteristics in land use types and topography, and deliver significant information for city planners and policy makers.

  1. Groundwater – The disregarded component in lake water and nutrient budgets. Part 2: effects of groundwater on nutrients

    Science.gov (United States)

    Lewandowski, Jörg; Meinikmann, Karin; Nützmann, Gunnar; Rosenberry, Donald O.

    2015-01-01

    Lacustrine groundwater discharge (LGD) transports nutrients from a catchment to a lake, which may fuel eutrophication, one of the major threats to our fresh waters. Unfortunately, LGD has often been disregarded in lake nutrient studies. Most measurement techniques are based on separate determinations of volume and nutrient concentration of LGD: Loads are calculated by multiplying seepage volumes by concentrations of exfiltrating water. Typically low phosphorus (P) concentrations of pristine groundwater often are increased due to anthropogenic sources such as fertilizer, manure or sewage. Mineralization of naturally present organic matter might also increase groundwater P. Reducing redox conditions favour P transport through the aquifer to the reactive aquifer-lake interface. In some cases, large decreases of P concentrations may occur at the interface, for example, due to increased oxygen availability, while in other cases, there is nearly no decrease in P. The high reactivity of the interface complicates quantification of groundwater-borne P loads to the lake, making difficult clear differentiation of internal and external P loads to surface water. Anthropogenic sources of nitrogen (N) in groundwater are similar to those of phosphate. However, the environmental fate of N differs fundamentally from P because N occurs in several different redox states, each with different mobility. While nitrate behaves essentially conservatively in most oxic aquifers, ammonium's mobility is similar to that of phosphate. Nitrate may be transformed to gaseous N2 in reducing conditions and permanently removed from the system. Biogeochemical turnover of N is common at the reactive aquifer-lake interface. Nutrient loads from LGD were compiled from the literature. Groundwater-borne P loads vary from 0.74 to 2900 mg PO4-P m−2 year−1; for N, these loads vary from 0.001 to 640 g m−2 year−1. Even small amounts of seepage can carry large nutrient loads due to often high

  2. Nutrients versus emerging contaminants-Or a dynamic match between subsidy and stress effects on stream biofilms.

    Science.gov (United States)

    Aristi, I; Casellas, M; Elosegi, A; Insa, S; Petrovic, M; Sabater, S; Acuña, V

    2016-05-01

    Freshwater ecosystems are threatened by multiple anthropogenic stressors, which might be differentiated into two types: those that reduce biological activity at all concentrations (toxic contaminants), and those that subsidize biological activity at low concentrations and reduce it at high concentrations (assimilable contaminants). When occurring in mixtures, these contaminants can have either antagonistic, neutral or synergistic effects; but little is known on their joint effects. We assessed the interaction effects of a mixture of assimilable and toxic contaminants on stream biofilms in a manipulative experiment using artificial streams, and following a factorial design with three nutrient levels (low, medium or high) and either presence or absence of a mixture of emerging contaminants (ciprofloxacin, erythromycin, diclofenac, methylparaben, and sulfamethoxazole). We measured biofilm biomass, basal fluorescence, gross primary production and community respiration. Our initial hypotheses were that biofilm biomass and activity would: increase with medium nutrient concentrations (subsidy effect), but decrease with high nutrient concentrations (stress effect) (i); decrease with emerging contaminants, with the minimum decrease at medium nutrient concentrations (antagonistic interaction between nutrients subsidy and stress by emerging contaminants) and the maximum decrease at high nutrient concentrations (synergistic interaction between nutrients and emerging contaminants stress) (ii). All the measured variables responded linearly to the available nutrients, with no toxic effect at high nutrient concentrations. Emerging contaminants only caused weak toxic effects in some of the measured variables, and only after 3-4 weeks of exposure. Therefore, only antagonistic interactions were observed between nutrients and emerging contaminants, as medium and high nutrient concentrations partly compensated the harmful effects of emerging contaminants during the first weeks of the

  3. In vitro reduction of dental erosion by low-concentration TiF4 solutions

    NARCIS (Netherlands)

    Vieira, A.M.; Ruben, J.L.; Bronkhorst, E.M.; Huysmans, M.C.D.N.J.M.

    2011-01-01

    The aims of this study were to compare daily versus single applications of low-concentration TiF(4) solutions for reduction of enamel erosion and to evaluate the enamel surface loss due to application of these solutions. Sixty bovine enamel samples were randomly divided into 2 groups: single versus

  4. In vitro Reduction of Dental Erosion by Low-Concentration TiF4 Solutions

    NARCIS (Netherlands)

    Vieira, A. M.; Ruben, J. L.; Bronkhorst, E. M.; Huysmans, M. C. D. N. J. M.

    2011-01-01

    The aims of this study were to compare daily versus single applications of low-concentration TiF4 solutions for reduction of enamel erosion and to evaluate the enamel surface loss due to application of these solutions. Sixty bovine enamel samples were randomly divided into 2 groups: single versus

  5. Dependence of the concentrations of "1"3"7Cs and potassium in extracted soil solutions on soil humidity before centrifugation

    International Nuclear Information System (INIS)

    Prorok, V.V.; Datsenko, O.Yi.; Bulavyin, L.A.; Zlens'kij, S.Je.; Melnichenko, L.Yu.; Rozuvan, S.G.; Poperenko, L.V.; White, P.J.

    2017-01-01

    Concentrations of 137Cs and potassium in solutions extracted by centrifugation from soils selected at some experimental sites in the 10-km Exclusion Zone of Chornobyl Nuclear Plant were determined. The results showed that for the majority of investigated soils, the concentration of 137Cs in soil solution depends on the humidity of the soil before centrifugation. It is possible to explain the dependence of the concentration of 137Cs in the soil solution on soil humidity from the dependence of the concentrations of molecules of different molecular-gravimetric fractions in soil solution on soil humidity. Considerable amount of 137Cs in soil solution is associated with these molecules, that is why the concentration of 137Cs in the extracted soil solution changes with the humidity of soil. These dependences differ between soils. For the majority of investigated soils the concentration of 137Cs in the extracted soil solution increases with increasing humidity of the soil. By contrast, soil humidity had no effect on the potassium concentration in the extracted soil solution for any soil investigated. It is concluded, that potassium is practically not associated with molecules of different molecular-gravimetric fractions in the extracted soil solutions

  6. Determination of the uranium concentration in soil solutions by the fission track registration technique

    International Nuclear Information System (INIS)

    Fernandes, G.P.

    1980-02-01

    The fission tracks registration technique was used to determine the uranium concentration in soil solutions. The Makrofol KG, a synthetic plastic manufactured by Bayer, was used as a detector and the wet method was applied. From the calibration curves obtained, it was possible to determine uranium concentrations in soil solutions, from 90 to 320 μg U/l, with an error between 9.4% and 4.0%, respectively. The method was applied to a few soil samples from Pocos de Caldas, Minas Gerais in Brazil. The uranium concentrations in the sample and residues were also determined by other methods to compare the results obtained; only one sample showed deviation from the results obtained by the fission tracks method. And this discrepancy was explained in a reasonable way. It was shown that the fission tracks technique can be used with sucess for application in soil solutions. (Author) [pt

  7. Computation of major solute concentrations and loads in German rivers using regression analysis.

    Science.gov (United States)

    Steele, T.D.

    1980-01-01

    Regression functions between concentrations of several inorganic solutes and specific conductance and between specific conductance and stream discharge were derived from intermittent samples collected for 2 rivers in West Germany. These functions, in conjunction with daily records of streamflow, were used to determine monthly and annual solute loadings. -from Author

  8. Major losses of nutrients following a severe drought in a boreal forest.

    Science.gov (United States)

    Houle, Daniel; Lajoie, Geneviève; Duchesne, Louis

    2016-11-28

    Because of global warming, the frequency and severity of droughts are expected to increase, which will have an impact on forest ecosystem health worldwide 1 . Although the impact of drought on tree growth and mortality is being increasingly documented 2-4 , very little is known about the impact on nutrient cycling in forest ecosystems. Here, based on long-term monitoring data, we report nutrient fluxes in a boreal forest before, during and following a severe drought in July 2012. During and shortly after the drought, we observed high throughfall (rain collected below the canopy) concentrations of nutrient base cations (potassium, calcium and magnesium), chlorine, phosphorus and dissolved organic carbon (DOC), differing by one to two orders of magnitude relative to the long-term normal, and resulting in important canopy losses. The high throughfall fluxes had repercussions in the soil solution at a depth of 30 cm, leading to high DOC, chlorine and potassium concentrations. The net potassium losses (atmospheric deposition minus leaching losses) following the drought were especially important, being the equivalent of nearly 20 years of net losses under 'normal' conditions. Our data show that droughts have unexpected impacts on nutrient cycling through impacts on tree canopy and soils and may lead to important episodes of potassium losses from boreal forest ecosystems. The potassium losses associated with drought will add to those originating from tree harvesting and from forest fires and insect outbreaks 5-7 (with the last two being expected to increase in the future as a result of climate change), and may contribute to reduced potassium availability in boreal forests in a warming world.

  9. Study on the spectrum of photonic crystal cavity and its application in measuring the concentration of NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yun [Nanjing Agricultural Univ., Nanjing (China). Dept. of Physics; Wuxi Institute of Commerce, Wuxi (China). School of Electromechanical Technology; Xie, Xun; Hao, Jiong-Ju; Yang, Hong-Wei [Nanjing Agricultural Univ., Nanjing (China). Dept. of Physics; Yang, Ze-Kun [Lanzhou Univ. (China). School of Information Science and Engineering; Xu, Zhi-Gang [Nanjing Agricultural Univ., Nanjing (China). College of Agriculture

    2017-07-01

    In this article, we propose an approach to measure solution concentrations by using photonic crystal cavities. Based on the experimental data, the refractive index of a NaCl solution is proportional to the concentration. Filling the proposed photonic crystal cavity with a NaCl solution, we calculate the spectral transmission using the transfer matrix method. We found that the cavity transmittance was proportional to the refractive index of the NaCl solution, and thus we obtained a linear relationship between cavity transmittance and the concentration of the NaCl solution. The formula was found by fitting the simulation results with experimental data. Such a formula can be applied to the measurement of an unknown concentration of NaCl solution utilizing a photonic crystal cavity.

  10. Nutrient and metal uptake in wetland plants at stormwater detension ponds

    DEFF Research Database (Denmark)

    Istenic, Darja; Arias, Carlos Alberto; Brix, Hans

    2011-01-01

    Nutrients and metals were analysed in tissues of various wetland plants growing in stormwater detention ponds in Denmark. Nutrient and metal concentrations in below and aboveground tissues were compared to the concentrations of the adjacent sediment. The results showed accumulation of heavy metal...

  11. The release of dissolved nutrients and metals from coastal sediments due to resuspension

    Science.gov (United States)

    Kalnejais, Linda H.; Martin, William R.; Bothner, Michael H.

    2010-01-01

    Coastal sediments in many regions are impacted by high levels of contaminants. Due to a combination of shallow water depths, waves, and currents, these sediments are subject to regular episodes of sediment resuspension. However, the influence of such disturbances on sediment chemistry and the release of solutes is poorly understood. The aim of this study is to quantify the release of dissolved metals (iron, manganese, silver, copper, and lead) and nutrients due to resuspension in Boston Harbor, Massachusetts, USA. Using a laboratory-based erosion chamber, a range of typical shear stresses was applied to fine-grained Harbor sediments and the solute concentration at each shear stress was measured. At low shear stress, below the erosion threshold, limited solutes were released. Beyond the erosion threshold, a release of all solutes, except lead, was observed and the concentrations increased with shear stress. The release was greater than could be accounted for by conservative mixing of porewaters into the overlying water, suggesting that sediment resuspension enhances the release of nutrients and metals to the dissolved phase. To address the long-term fate of resuspended particles, samples from the erosion chamber were maintained in suspension for 90. h. Over this time, 5-7% of the particulate copper and silver was released to the dissolved phase, while manganese was removed from solution. Thus resuspension releases solutes both during erosion events and over a longer timescale due to reactions of suspended particles in the water column. The magnitude of the annual solute release during erosion events was estimated by coupling the erosion chamber results with a record of bottom shear stresses simulated by a hydrodynamic model. The release of dissolved copper, lead, and phosphate due to resuspension is between 2% and 10% of the total (dissolved plus particulate phase) known inputs to Boston Harbor. Sediment resuspension is responsible for transferring a significant

  12. Formation and stabilization of anionic metal complexes in concentrated aqueous quaternary ammonium salt solutions

    International Nuclear Information System (INIS)

    Aronson, F.L.; Hwang, L.L.Y.; Ronca, N.; Solomon, N.A.; Steigman, J.

    1985-01-01

    Anionic complexes of transition metals were stabilized in aqueous solutions containing high concentrations of various short-chain quaternary ammonium salts. Compounds with longer paraffin chains were effective in much less concentrated solution. Complex ions were detected spectrophotometrically. FeCl 4 - , which is usually formed in concentrated HCl, was the predominant Fe(III) complex in 30 m choline chloride containing only 0.12 M HCl. A yellow transitory Tc(VII) chloro-addition intermediate, formed in the reduction of TcO 4 - by concentrated HCl, was stabilized when the solution also contained 25 m choline chloride. Its spectrum, as well as the isolation of an already known Tc(VII) bipyridyl complex, is reported. Concentrated organic electrolytes also stabilized Tc(V) oxide halides against disproportionation and Tc(IV) hexahalides against hydrolysis. Halochromates of Cr(VI) were formed and stabilized in dilute acid containing quaternary ammonium salts. Their UV spectra showed the well-resolved vibronic fine structure associated with the symmetric chromium-to-oxygen charge-transfer band. It is known that these progressions are resolved in aprotic solvents, but not in aqueous acidic solution alone, and that the loss of fine structure in aqueous media is due to hydrogen bonding. The stabilization of anionic metal complexes and the resolution of vibronic structure in halochromates are probably consequences of water-structure-enforced ion paring. The present work suggests that the water molecules in immediate contact with the complex anions are more strongly hydrogen bonded to each other than to the complex. 21 references, 4 figures

  13. Low-Concentration Indium Doping in Solution-Processed Zinc Oxide Films for Thin-Film Transistors

    Directory of Open Access Journals (Sweden)

    Xue Zhang

    2017-07-01

    Full Text Available We investigated the influence of low-concentration indium (In doping on the chemical and structural properties of solution-processed zinc oxide (ZnO films and the electrical characteristics of bottom-gate/top-contact In-doped ZnO thin-film transistors (TFTs. The thermogravimetry and differential scanning calorimetry analysis results showed that thermal annealing at 400 °C for 40 min produces In-doped ZnO films. As the In content of ZnO films was increased from 1% to 9%, the metal-oxygen bonding increased from 5.56% to 71.33%, while the metal-hydroxyl bonding decreased from 72.03% to 9.63%. The X-ray diffraction peaks and field-emission scanning microscope images of the ZnO films with different In concentrations revealed a better crystalline quality and reduced grain size of the solution-processed ZnO thin films. The thickness of the In-doped ZnO films also increased when the In content was increased up to 5%; however, the thickness decreased on further increasing the In content. The field-effect mobility and on/off current ratio of In-doped ZnO TFTs were notably affected by any change in the In concentration. Considering the overall TFT performance, the optimal In doping concentration in the solution-processed ZnO semiconductor was determined to be 5% in this study. These results suggest that low-concentration In incorporation is crucial for modulating the morphological characteristics of solution-processed ZnO thin films and the TFT performance.

  14. Effect of solution concentration on MEH-PPV thin films

    Science.gov (United States)

    Affendi, I. H. H.; Sarah, M. S. P.; Alrokayan, Salman A. H.; Khan, Haseeb A.; Rusop, M.

    2018-05-01

    MEH-PPV thin films were prepared with a mixture of THF (tetrahydrofuran) solution deposited by spin coating method. The surface topology of MEH-PPV thin film were characterize by atomic force microscopy (AFM) and optical properties of absorption spectra were characterized by using Ultraviolet-visible-near-infrared (UV-Vis-NIR). The MEH-PPV concentration variation affects the surface and optical properties of the thin film where 0.5 mg/ml MEH-PPV concentration have a good surface topology provided the same film also gives the highest absorption coefficient were then deposited to a TiO2 thin film forming composite layer. The composite layer then shows low current flow of short circuit current of Isc = -5.313E-7 A.

  15. Effect of solute atom concentration on vacancy cluster formation in neutron-irradiated Ni alloys

    Science.gov (United States)

    Sato, Koichi; Itoh, Daiki; Yoshiie, Toshimasa; Xu, Qiu; Taniguchi, Akihiro; Toyama, Takeshi

    2011-10-01

    The dependence of microstructural evolution on solute atom concentration in Ni alloys was investigated by positron annihilation lifetime measurements. The positron annihilation lifetimes in pure Ni, Ni-0.05 at.%Si, Ni-0.05 at.%Sn, Ni-Cu, and Ni-Ge alloys were about 400 ps even at a low irradiation dose of 3 × 10 -4 dpa, indicating the presence of microvoids in these alloys. The size of vacancy clusters in Ni-Si and Ni-Sn alloys decreased with an increase in the solute atom concentration at irradiation doses less than 0.1 dpa; vacancy clusters started to grow at an irradiation dose of about 0.1 dpa. In Ni-2 at.%Si, irradiation-induced segregation was detected by positron annihilation coincidence Doppler broadening measurements. This segregation suppressed one-dimensional (1-D) motion of the interstitial clusters and promoted mutual annihilation of point defects. The frequency and mean free path of the 1-D motion depended on the solute atom concentration and the amount of segregation.

  16. Concentrated aqueous sodium chloride solution in clays at thermodynamic conditions of hydraulic fracturing: Insight from molecular dynamics simulations

    Science.gov (United States)

    Svoboda, Martin; Lísal, Martin

    2018-06-01

    To address a high salinity of flow-back water during hydraulic fracturing, we use molecular dynamics (MD) simulations and study the thermodynamics, structure, and diffusion of concentrated aqueous salt solution in clay nanopores. The concentrated solution results from the dissolution of a cubic NaCl nanocrystal, immersed in an aqueous NaCl solution of varying salt concentration and confined in clay pores of a width comparable to the crystal size. The size of the nanocrystal equals to about 18 Å which is above a critical nucleus size. We consider a typical shale gas reservoir condition of 365 K and 275 bar, and we represent the clay pores as pyrophyllite and Na-montmorillonite (Na-MMT) slits. We employ the Extended Simple Point Charge (SPC/E) model for water, Joung-Cheatham model for ions, and CLAYFF for the slit walls. We impose the pressure in the normal direction and the resulting slit width varies from about 20 to 25 Å when the salt concentration in the surrounding solution increased from zero to an oversaturated value. By varying the salt concentration, we observe two scenarios. First, the crystal dissolves and its dissolution time increases with increasing salt concentration. We describe the dissolution process in terms of the number of ions in the crystal, and the crystal size and shape. Second, when the salt concentration reaches a system solubility limit, the crystal grows and attains a new equilibrium size; the crystal comes into equilibrium with the surrounding saturated solution. After crystal dissolution, we carry out canonical MD simulations for the concentrated solution. We evaluate the hydration energy, density profiles, orientation distributions, hydrogen-bond network, radial distribution functions, and in-plane diffusion of water and ions to provide insight into the microscopic behaviour of the concentrated aqueous sodium chloride solution in interlayer galleries of the slightly hydrophobic pyrophyllite and hydrophilic Na-MMT pores.

  17. Wildfire Effects on In-stream Nutrient Processing and Hydrologic Transport

    Science.gov (United States)

    Rhea, A.; Covino, T. P.; Rhoades, C.; Fegel, T.

    2017-12-01

    In many forests throughout the Western U.S., drought, climate change, and growing fuel loads are contributing to increased fire frequency and severity. Wildfires can influence watershed nutrient retention as they fundamentally alter the biological composition and physical structure in upland landscapes, riparian corridors, and stream channels. While numerous studies have documented substantial short-term increases in stream nutrient concentrations and export (particularly reactive nitrogen, N) following forest fires, the long-term implications for watershed nutrient cycling remain unclear. For example, recent work indicates that nitrate concentrations and export can remain elevated for a decade or more following wildfire, yet the controls on these processes are unknown. In this research, we use empirical observations from nutrient tracer injections, nutrient diffusing substrates, and continuous water quality monitoring to isolate biological and physical controls on nutrient export across a burn-severity gradient. Tracer results demonstrate substantial stream-groundwater exchange, but little biological nutrient uptake in burned streams. This in part explains patterns of elevated nutrient export. Paired nutrient diffusing substrate experiments allow us to further investigate shifts in N, phosphorus, and carbon limitation that may suppress post-fire stream nutrient uptake. By isolating the mechanisms that reduce the capacity of fire-affected streams to retain and transform nutrient inputs, we can better predict dynamics in post-fire water quality and help prioritize upland and riparian restoration.

  18. Modeling nutrient in-stream processes at the watershed scale using Nutrient Spiralling metrics

    Science.gov (United States)

    Marcé, R.; Armengol, J.

    2009-07-01

    One of the fundamental problems of using large-scale biogeochemical models is the uncertainty involved in aggregating the components of fine-scale deterministic models in watershed applications, and in extrapolating the results of field-scale measurements to larger spatial scales. Although spatial or temporal lumping may reduce the problem, information obtained during fine-scale research may not apply to lumped categories. Thus, the use of knowledge gained through fine-scale studies to predict coarse-scale phenomena is not straightforward. In this study, we used the nutrient uptake metrics defined in the Nutrient Spiralling concept to formulate the equations governing total phosphorus in-stream fate in a deterministic, watershed-scale biogeochemical model. Once the model was calibrated, fitted phosphorus retention metrics where put in context of global patterns of phosphorus retention variability. For this purpose, we calculated power regressions between phosphorus retention metrics, streamflow, and phosphorus concentration in water using published data from 66 streams worldwide, including both pristine and nutrient enriched streams. Performance of the calibrated model confirmed that the Nutrient Spiralling formulation is a convenient simplification of the biogeochemical transformations involved in total phosphorus in-stream fate. Thus, this approach may be helpful even for customary deterministic applications working at short time steps. The calibrated phosphorus retention metrics were comparable to field estimates from the study watershed, and showed high coherence with global patterns of retention metrics from streams of the world. In this sense, the fitted phosphorus retention metrics were similar to field values measured in other nutrient enriched streams. Analysis of the bibliographical data supports the view that nutrient enriched streams have lower phosphorus retention efficiency than pristine streams, and that this efficiency loss is maintained in a wide

  19. Autonomous nutrient detection for water quality monitoring

    OpenAIRE

    Maher, Damien; Cleary, John; Cogan, Deirdre; Diamond, Dermot

    2012-01-01

    The ever increasing demand for real time environmental monitoring is currently being driven by strong legislative and societal drivers. Low cost autonomous environmental monitoring systems are required to meet this demand as current monitoring solutions are insufficient. This poster presents an autonomous nutrient analyser platform for water quality monitoring. Results from a field trial of the nutrient analyser are reported along with current work to expand the range of water quality targ...

  20. Solute concentration dependence of the decay curves of the liquid scintillation

    International Nuclear Information System (INIS)

    Onishi, Masayoshi; Niki, Eiji.

    1976-01-01

    The decay curves of the liquid scintillation of 2,5-diphenyloxazole (PPO) in toluene by the irradiation of β ray from 14 C were measured. Solute concentration dependences of the decay times of the fast and slow components were studied. The decay time tau sub(f) of the fast component of the air saturated scintillator was the smallest at 1.8x10 -2 --4.5x10 -2 mol/l, and about (3.4--3.5)ns. When the concentration became less than 1.8x10 -2 mol/l, the peak of the decay curve became roundish and the pulse width became large. The increase of the necessary time for the energy transfer due to the difficulty of the nonradiative transfer from excited solvent molecules to the solute was the reason. When the concentration became less than about 2.26x10 -3 mol/l, tau sub(f) became larger and the energy transfer became radiative. The pulse width and tau sub(f) were very small because of oxygen quenching compared with oxygen free. At higher concentrations such as 1.6x10 -1 and 2.3x10 -1 mol/l, the effect of the PPO excimer was observed on the fast component, and tau sub(f) became larger apparently. This denied the presumption of the close relation between PPO molecular interaction and the slow component together with the fact that the decay time tau sub(s) of the slow component was independent of PPO concentration. (auth.)

  1. The influence of surface roughness and solution concentration on pool boiling process in Diethanolamine aqueous solution

    Science.gov (United States)

    Khoshechin, Mohsen; Salimi, Farhad; Jahangiri, Alireza

    2018-04-01

    In this research, the effect of surface roughness and concentration of solution on bubble departing frequency and nucleation site density for pool boiling of water/diethanolamine (DEA) binary solution were investigated experimentally. In this investigation, boiling heat transfer coefficient, bubble departing frequency and nucleation site density have been experimentally investigated in various concentrations and heat fluxes. Microstructured surfaces with a wide range of well-defined surface roughness were fabricated, and a heat flux between 1.5-86 kW/m2 was achieved under atmospheric conditions. The Results indicated that surface roughness and concentration of solution increase the bubble departing frequency and nucleation site density with increasing heat flux. The boiling heat transfer coefficient in mixtures of water/DEA increases with increasing concentration of DEA in water. The experimental results were compared with predictions of several used correlations in the literatures. Results showed that the boiling heat transfer coefficients of this case study are much higher than the predicted values by major existing correlations and models. The excellent agreement for bubble departing frequency found between the models of Jackob and Fritz (1966) and experimental data and also the nucleation site density were in close agreement with the model of Paul (1983) data. f bubble departure frequency, 1/s or Hz N Number of nucleation sites per area per time R c Minimum cavity size, m D c critical diameter, m g gravitational acceleration, m/s2 ρ density, kg/m3 T temperature, °c ΔT temperature difference, °c d d vapor bubble diameter, m h fg enthalpy of vaporization, J/kg R Roughness, μm Ja Jakob number cp specific heat, J/kg °c Pr Prandtl number Ar Archimedes number h Heat transfer coefficient, J/(m2 °c) tg time it takes to grow a bubble, s q/A heat flux (kW/m2) tw time required to heat the layer, s gc Correction coefficient of incompatible units R a Surface

  2. The influence of plutonium concentration and solution flow rate on the effective capacity of macroporous anion exchange resin

    International Nuclear Information System (INIS)

    Marsh, S.F.; Gallegos, T.D.

    1987-07-01

    The principal aqueous process used to recover and purify plutonium at the Los Alamos Plutonium Facility is anion exchange in nitric acid. Previous studies with gel-type anion exchange resin have shown an inverse relationship between plutonium concentration in the feed solution and the optimum flow rate for this process. Because gel-type resin has been replaced with macroporous resin at Los Alamos, the relationship between plutonium concentration and solution flow rate was reexamined with the selected Lewatit MP-500-FK resin using solutions of plutonium in nitric acid and in nitric acid with high levels of added nitrate salts. Our results with this resin differ significantly from previous data obtained with gel-type resin. Flow-rate variation from 10 to 80 liters per hour had essentially no effect on the measured quantities of plutonium sorbed by the macroporous resin. However, the effect of plutonium concentration in the feed solutions was pronounced, as feed solutions that contained the highest concentrations of plutonium also produced the highest resin loadings. The most notable effect of high concentrations of dissolved nitrate salts in these solutions was an increased resin capacity for plutonium at low flow rates. 16 refs., 7 figs., 2 tabs

  3. Removal of cadmium (II) from aqueous solution: A comparative study of raw attapulgite clay and a reusable waste–struvite/attapulgite obtained from nutrient-rich wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hao [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Wang, Xuejiang, E-mail: wangxj@tongji.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Ma, Jinxing, E-mail: jinxing.ma@unsw.edu.au [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Xia, Peng; Zhao, Jianfu [State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)

    2017-05-05

    Highlights: • Both nutrient recovery and Cd(II) removal were achieved by MAP/APT. • The nutrient recovery process was used as a novel method of modification. • Compared with raw APT, MAP/APT enhanced Cd(II) adsorption capacity. • Cd(II) adsorption mechanisms from aqueous solution were extensively investigated. - Abstract: In this study, raw attapulgite (APT) and a novel adsorbent, struvite/attapulgite (MAP/APT) obtained from nutrient-rich wastewater treated by MgO modified APT, were applied as the absorbent for Cd(II) ion removal from aqueous solution. The two adsorbents were characterized by BET, SEM-EDS, XRD, FT-IR. Raw APT and MAP/APT separately presented the maximum Cd(II) adsorption capacities of 10.38 mg/g and 121.14 mg/g at pH of 5.45. The Cd(II) adsorption on raw APT and MAP/APT could be well fitted by Freundlich isotherm and Langmuir isotherm, respectively. Pseudo-second order equation was able to properly describe the kinetics of Cd(II) adsorption by raw APT and MAP/APT. The calculated thermodynamic parameters indicated that Cd(II) adsorption onto raw APT and MAP/APT were spontaneous and endothermic. An economic evaluation revealed that the treatment costs of the adsorption process by raw APT and MPA/APT were 0.013 $ per 1000 mg Cd and 0.004 $ per 1000 mg Cd, respectively.

  4. Optimal N:P ratios of growth media: quantification of nutrient-replete growth rates in five ion hyperspace for Chlorella vulgaris (Dinophyceae) and Peridinium cinctum (Dinophyceae).

    Science.gov (United States)

    In this study our principal goal was to quantify the main effects and interactions of several primary nutrient and bulk solution ions. The total ion concentration range chosen spans fresh to brackish waters (1-30 milliMolar) and explores most of the hypervolume delineated by the five ion/concentrat...

  5. Long-term trends in nutrient budgets of the western Dutch Wadden Sea (1976-2012)

    Science.gov (United States)

    Jung, A. S.; Brinkman, A. G.; Folmer, E. O.; Herman, P. M. J.; van der Veer, H. W.; Philippart, C. J. M.

    2017-09-01

    Long-term field observations of nitrogen [N] and phosphorus [P] concentrations were used to construct nutrient budgets for the western Dutch Wadden Sea between 1976 and 2012. Nutrients come into the western Dutch Wadden Sea via river runoff, through exchange with the coastal zone of the North Sea, neighbouring tidal basins and through atmospheric deposition (for N). The highest concentrations in phosphorus and nitrogen were observed in the mid-1980s. Improved phosphorus removal at waste water treatment plants, management of fertilization in agriculture and removal of phosphates from detergents led to reduced riverine nutrient inputs and, consequently, reduced nutrient concentrations in the Wadden Sea. The budgets suggest that the period of the initial net import of phosphorus and nitrogen switched to a net export in 1981 for nitrogen and in 1992 for phosphorus. Such different behaviour in nutrient budgets during the rise and fall of external nutrient concentrations may be the result of different sediment-water exchange dynamics for P and N. It is hypothesized that during the period of increasing eutrophication (1976-1981) P, and to a lesser degree N, were stored in sediments as organic and inorganic nutrients. In the following period (1981-1992) external nutrient concentrations (especially in the North Sea) decreased, but P concentrations in the Wadden Sea remained high due to prolonged sediment release, whilst denitrification removed substantial amounts of N. From 1992 onwards, P and N budgets were closed by net loss, most probably because P stores were then depleted and denitrification continued. Under the present conditions (lower rates of sediment import and depleted P stores), nutrient concentrations in this area are expected to be more strongly influenced by wind-driven exchange with the North Sea and precipitation-driven discharge from Lake IJssel. This implies that the consequences of climate change will be more important, than during the 1970s and 1980s.

  6. Ion-exchange concentration of inorganic anions from aqueous solution

    Directory of Open Access Journals (Sweden)

    L. P. Bondareva

    2016-01-01

    Full Text Available Monitoring of natural waters in the present time - consuming process, the accuracy of which is influenced by many factors: the composition of water, the presence of impurities and "interfering" components. The water sample preparation process includes the step of concentration and separation of ions determined. The most versatile, efficient, and frequently used method is the concentration of inorganic anions from aqueous solutions by ion exchanger, which can optimize the composition of water to the optimal for identification and quantitative determination of anions. The characteristics of sorption chloride, nitrate and sulfate ions of basic anion exchange resin AВ-17 and Purolite A430 were compared in the article. The constants of protolysis of ion exchangers both AB 17 and Purolite A430 are the same and equal 0.037 ± 0,002. The value of total capacity (POE Purolite A430 was 4.3 mmol/g, AB 17 – 3.4 mmol/g. The studied ion exchangers have the same type of ionic groups – quaternary ammonium, but their number and denotes differ. The number of quaternary ammonium groups is higher in Purolite A430, respectively the number of absorbed anions of these ion exchanger is higher. The values of dynamic exchange capacity (DOE of ion exchanger Purolite A430 is higher than these values of AB-17 and equal to 1.48 ± 0.03 mmol / dm3 for chloride ion, 1.50 ± 0.03 mmol / dm3 for nitrate ion, 1.62 ± 0.03 mmol / dm3 for sulfate ion. The values of the POE and DOE of anion-exchange resins Purolite A430 and AV-17 and the characteristics of the individual sorption of chloride, nitrate, sulfate ions showed an advantage of the Purolite for the concentrationing of anions. It is found that times of anions sorption from triple-anion solutions by Purolite A430 are significantly different for different anions, and these times are close for anion-exchanger AV-17. It proves the possibility of quantitative separation and concentration by anion-exchanger Purolite A430.

  7. Communication: Modeling of concentration dependent water diffusivity in ionic solutions: Role of intermolecular charge transfer

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Yi; Berkowitz, Max L., E-mail: maxb@unc.edu, E-mail: ykanai@unc.edu; Kanai, Yosuke, E-mail: maxb@unc.edu, E-mail: ykanai@unc.edu [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States)

    2015-12-28

    The translational diffusivity of water in solutions of alkali halide salts depends on the identity of ions, exhibiting dramatically different behavior even in solutions of similar salts of NaCl and KCl. The water diffusion coefficient decreases as the salt concentration increases in NaCl. Yet, in KCl solution, it slightly increases and remains above bulk value as salt concentration increases. Previous classical molecular dynamics simulations have failed to describe this important behavior even when polarizable models were used. Here, we show that inclusion of dynamical charge transfer among water molecules produces results in a quantitative agreement with experiments. Our results indicate that the concentration-dependent diffusivity reflects the importance of many-body effects among the water molecules in aqueous ionic solutions. Comparison with quantum mechanical calculations shows that a heterogeneous and extended distribution of charges on water molecules around the ions due to ion-water and also water-water charge transfer plays a very important role in controlling water diffusivity. Explicit inclusion of the charge transfer allows us to model accurately the difference in the concentration-dependent water diffusivity between Na{sup +} and K{sup +} ions in simulations, and it is likely to impact modeling of a wide range of systems for medical and technological applications.

  8. Simulating Osmotic Equilibria: A New Tool for Calculating Activity Coefficients in Concentrated Aqueous Salt Solutions.

    Science.gov (United States)

    Bley, Michael; Duvail, Magali; Guilbaud, Philippe; Dufrêche, Jean-François

    2017-10-19

    Herein, a new theoretical method is presented for predicting osmotic equilibria and activities, where a bulk liquid and its corresponding vapor phase are simulated by means of molecular dynamics using explicit polarization. Calculated time-averaged number density profiles provide the amount of evaporated molecules present in the vapor phase and consequently the vapor-phase density. The activity of the solvent and the corresponding osmotic coefficient are determined by the vapor density at different solute concentrations with respect to the reference vapor density of the pure solvent. With the extended Debye-Hückel equation for the activity coefficient along with the corresponding Gibbs-Duhem relation, the activity coefficients of the solutes are calculated by fitting the osmotic coefficients. A simple model based on the combination of Poisson processes and Maxwell-Boltzmann velocity distributions is introduced to interpret statistical phenomena observed during the simulations, which are related to evaporation and recondensation. This method is applied to aqueous dysprosium nitrate [Dy(NO 3 ) 3 ] solutions at different concentrations. The obtained densities of the liquid bulk and the osmotic and activity coefficients are in good agreement with the experimental results for concentrated and saturated solutions. Density profiles of the liquid-vapor interface at different concentrations provide detailed insight into the spatial distributions of all compounds.

  9. Prenatal lipid-based nutrient supplements increase cord leptin concentration in pregnant women from rural Burkina Faso.

    Science.gov (United States)

    Huybregts, Lieven; Roberfroid, Dominique; Lanou, Hermann; Meda, Nicolas; Taes, Youri; Valea, Innocent; D'Alessandro, Umberto; Kolsteren, Patrick; Van Camp, John

    2013-05-01

    In developing countries, prenatal lipid-based nutrient supplements (LNSs) were shown to increase birth size; however, the mechanism of this effect remains unknown. Cord blood hormone concentrations are strongly associated with birth size. Therefore, we hypothesize that LNSs increase birth size through a change in the endocrine regulation of fetal development. We compared the effect of daily prenatal LNSs with multiple micronutrient tablets on cord blood hormone concentrations using a randomized, controlled design including 197 pregnant women from rural Burkina Faso. Insulin-like growth factors (IGF) I and II, their binding proteins IGFBP-1 and IGFBP-3, leptin, cortisol, and insulin were quantified in cord sera using immunoassays. LNS was associated with higher cord blood leptin mainly in primigravidae (+57%; P = 0.02) and women from the highest tertile of BMI at study inclusion (+41%; P = 0.02). We did not find any significant LNS effects on other measured cord hormones. The observed increase in cord leptin was associated with a significantly higher birth weight. Cord sera from small-for-gestational age newborns had lower median IGF-I (-9 μg/L; P = 0.003), IGF-II (-79 μg/L; P = 0.003), IGFBP-3 (-0.7 μg/L; P = 0.007), and leptin (-1.0 μg/L; P = 0.016) concentrations but higher median cortisol (+18 μg/L; P = 0.037) concentrations compared with normally grown newborns. Prenatal LNS resulted in increased cord leptin concentrations in primigravidae and mothers with higher BMI at study inclusion. The elevated leptin concentrations could point toward a higher neonatal fat mass.

  10. Cadmium toxicity to two marine phytoplankton under different nutrient conditions

    International Nuclear Information System (INIS)

    Miao, A.-J.; Wang, W.-X.

    2006-01-01

    Cd accumulation and toxicity in two marine phytoplankton (diatom Thalassiosira weissflogii and dinoflagellate Prorocentrum minimum) under different nutrient conditions (nutrient-enriched, N- and P-starved conditions) were examined in this study. Strong interactions between the nutrients and Cd uptake by the two algal species were found. Cd accumulation as well as N and P starvation themselves inhibited the assimilation of N, P, and Si by the phytoplankton. Conversely, N starvation strongly inhibited Cd accumulation but no influence was observed under P starvation. However, the Cd accumulation difference between nutrient-enriched and N-starved cells was smaller when [Cd 2+ ] was increased in the medium, indicating that net Cd accumulation was less dependent on the N-containing ligands at high-Cd levels. As for the subcellular distribution of the accumulated Cd, most was distributed in the insoluble fraction of T. weissflogii while it was evenly distributed in the soluble and insoluble fractions of P. minimum at low-Cd levels. A small percentage of cellular Cd ( 2+ ], which increased when the [Cd 2+ ] increased. Cd toxicity in phytoplankton was quantified as depression of growth and maximal photosynthetic system II quantum yield, and was correlated with the [Cd 2+ ], intracellular Cd concentration, and Cd concentrations in the cell-surface-adsorbed, soluble, and insoluble fractions. According to the estimated median inhibition concentration (IC50) based on the different types of Cd concentration, the toxicity difference among the different nutrient-conditioned cells was the smallest when the Cd concentration in the soluble fraction was used, suggesting that it may be the best predictor of Cd toxicity under different nutrient conditions

  11. The determination of hydroxide and carbonate in concentrated sodium chloride solutions

    NARCIS (Netherlands)

    Roolvink, W.B.; Bos, M.

    1980-01-01

    A computer method for the determination of carbonate and hydroxide in concentrated (2.89 M) sodium chloride solutions is described. The method is based on multiparametric curve-fitting and can also be applied to salts of dibasic acids with unknown equilibrium constants. The systematic error is not

  12. Thermodynamics of curium(III) in concentrated electrolyte solutions: formation of sulfate complexes in NaCl/Na2SO4 solutions

    International Nuclear Information System (INIS)

    Paviet, P.; Fanghaenel, T.; Klenze, R.; Kim, J.I.

    1996-01-01

    The formation of sulfate complexes of Curium in aqueous solutions is studied by time resolved laser fluorescence spectroscopy (TRLFS) at 25 C. The species Cm 3+ , Cm(SO 4 ) - , Cm(SO 4 ) - 2 and Cm(SO 4 ) 3- 3 are quantified spectroscopically in the trace concentration range by peak deconvolution of fluorescence emission spectra. The complex formation equilibria are measured in NaCl/ Na 2 SO 4 solutions of constant ionic strength (3 molal) as a function of the sulfate concentration. The stability constants of Cm(SO 4 ) + and Cm(SO 4 ) - 2 are determined to be log β 1 = 0.93±0.08 and log β 2 = 0.61±0.08, respectively. The complex Cm(SO 4 ) 3- 3 is found to be stable only at very high sulfate concentrations (above 1 molal) and therefore not considered for further evaluation. (orig.)

  13. Fissile materials in solution concentration measured by active neutron interrogation

    International Nuclear Information System (INIS)

    Romeyer Dherbey, J.; Passard, Ch.; Cloue, J.; Bignan, G.

    1993-01-01

    The use of the active neutron interrogation to measure the concentration of plutonium contained in flow solutions is particularly interesting for fuel reprocessing plants. Indeed, this method gives a signal which is in a direct relation with the fissile materials concentration. Moreover, it is less sensitive to the gamma dose rate than the other nondestructive methods. Two measure methods have been evolved in CEA. Their principles are given into details in this work. The first one consists to detect fission delayed neutrons induced by a 252 Cf source. In the second one fission prompt neutrons induced by a neutron generator of 14 MeV are detected. (O.M.)

  14. Morphology-dependent water budgets and nutrient fluxes in arctic thaw ponds

    Science.gov (United States)

    Koch, Joshua C.; Gurney, Kirsty; Wipfli, Mark S.

    2014-01-01

    Thaw ponds on the Arctic Coastal Plain of Alaska are productive ecosystems, providing habitat and food resources for many fish and bird species. Permafrost in this region creates unique pond morphologies: deep troughs, shallow low-centred polygons (LCPs) and larger coalescent ponds. By monitoring seasonal trends in pond volume and chemistry, we evaluated whether pond morphology and size affect water temperature and desiccation, and nitrogen (N) and phosphorus (P) fluxes. Evaporation was the largest early-summer water flux in all pond types. LCPs dried quickly and displayed high early-summer nutrient concentrations and losses. Troughs consistently received solute-rich subsurface inflows, which accounted for 12 to 42 per cent of their volume and may explain higher P in the troughs. N to P ratios increased and ammonium concentrations decreased with pond volume, suggesting that P and inorganic N availability may limit ecosystem productivity in older, larger ponds. Arctic summer temperatures will likely increase in the future, which may accelerate mid-summer desiccation. Given their morphology, troughs may remain wet, become warmer and derive greater nutrient loads from their thawing banks. Overall, seasonal- to decadal-scale warming may increase ecosystem productivity in troughs relative to other Arctic Coastal Plain ponds. 

  15. Nutrient depletion in Bacillus subtilis biofilms triggers matrix production

    International Nuclear Information System (INIS)

    Zhang, Wenbo; Seminara, Agnese; Suaris, Melanie; Angelini, Thomas E; Brenner, Michael P; Weitz, David A

    2014-01-01

    Many types of bacteria form colonies that grow into physically robust and strongly adhesive aggregates known as biofilms. A distinguishing characteristic of bacterial biofilms is an extracellular polymeric substance (EPS) matrix that encases the cells and provides physical integrity to the colony. The EPS matrix consists of a large amount of polysaccharide, as well as protein filaments, DNA and degraded cellular materials. The genetic pathways that control the transformation of a colony into a biofilm have been widely studied, and yield a spatiotemporal heterogeneity in EPS production. Spatial gradients in metabolites parallel this heterogeneity in EPS, but nutrient concentration as an underlying physiological initiator of EPS production has not been explored. Here, we study the role of nutrient depletion in EPS production in Bacillus subtilis biofilms. By monitoring simultaneously biofilm size and matrix production, we find that EPS production increases at a critical colony thickness that depends on the initial amount of carbon sources in the medium. Through studies of individual cells in liquid culture we find that EPS production can be triggered at the single-cell level by reducing nutrient concentration. To connect the single-cell assays with conditions in the biofilm, we calculate carbon concentration with a model for the reaction and diffusion of nutrients in the biofilm. This model predicts the relationship between the initial concentration of carbon and the thickness of the colony at the point of internal nutrient deprivation. (paper)

  16. The influence of change of concentration of sum of nutrient elements on uptake 137Cs from inert substrate to the lettuce

    International Nuclear Information System (INIS)

    Alipbekov, O.A.; Dlimbetova, G.K.

    2002-01-01

    Radiation ecology has become the science of applied character after the numbers of great accidents at the nuclear fuel cycle enterprises (United Kingdom, 1957; Russia,1957; Ukraine, 1986). The success of the fight on the consequences liquidations of the uncontrolled fallen artificial radionuclides on the agricultural fields depends a lot on the correct use of accumulated division products in the soil-plant system in the field migration appropriateness. The considerable lowering of radionuclides uptake into the plants from the soil can be achieved by increase of disability of products fastening of soil division. At the same time the addition of the stuff with high sorption and fixing characteristics into the soil, as a rule, gives a considerable effect only in the first period of their use. Later the fixed isotopes can come into ion-exchange process again after the achievement of the balance condition with the soil-absorbing complex, i.e. pass in the more mobile forms. Entering of mineral fertilizers into the soil often leads to the contradictory results, so the search in this direction is going on. The given information emphasizes the actuality of the further studying the methods of regulation of long living radionuclides availability from the soil to the plants with the help of the nutrient mineral elements. The aim of the present work is the study of the influence of concentration of sum of basic nutrient elements (nitrogen, phosphorus, potassium, calcium, magnesium, iron, copper, zinc, manganese, cobalt, molybdenum, boron) on the uptake of 137 Cs from the inert substrate to the Lettuce plants. The vegetation experiments were carried out in one liter polyethylene vascular. One liter of milled quartz sand (size of the fractions was 0.5-1.0 mm) was put into each vascular specially cleaned from admixtures. The nutrient elements were added according to Rinkis. The results of the carried out researches have shown that the decrease of the concentration of sum of macro

  17. Absorption capacity and viscosity for CO_2 capture process using high concentrated PZ-DEAE aqueous solution

    International Nuclear Information System (INIS)

    Fu, Dong; Wang, LeMeng; Mi, ChenLu; Zhang, Pan

    2016-01-01

    Highlights: • Absorption of CO_2 in high concentrated DEAE-PZ aqueous solutions were measured. • Viscosities of CO_2-unloaded and CO_2-loaded DEAE-PZ aqueous solutions were measured. • Weiland equation was used to calculate the viscosities. • Effects of temperature, concentration and CO_2 loading on viscosity were demonstrated. - Abstract: The absorption capacity of CO_2 in piperazine (PZ) promoted 2-diethylaminoethanol (DEAE) aqueous solution was measured. The viscosities of both CO_2-unloaded and CO_2-loaded PZ-DEAE aqueous solutions were measured and then modelled. The temperatures ranged from 303.2 K to 323.2 K. The mass fraction of PZ and DEAE respectively ranged from 0 to 0.075 and 0.3 to 0.5. The temperature and concentration dependences of absorption capacity were determined. The effects of temperature, mass fraction and CO_2 loading on viscosities are demonstrated.

  18. Predicting the activity coefficients of free-solvent for concentrated globular protein solutions using independently determined physical parameters.

    Directory of Open Access Journals (Sweden)

    Devin W McBride

    Full Text Available The activity coefficient is largely considered an empirical parameter that was traditionally introduced to correct the non-ideality observed in thermodynamic systems such as osmotic pressure. Here, the activity coefficient of free-solvent is related to physically realistic parameters and a mathematical expression is developed to directly predict the activity coefficients of free-solvent, for aqueous protein solutions up to near-saturation concentrations. The model is based on the free-solvent model, which has previously been shown to provide excellent prediction of the osmotic pressure of concentrated and crowded globular proteins in aqueous solutions up to near-saturation concentrations. Thus, this model uses only the independently determined, physically realizable quantities: mole fraction, solvent accessible surface area, and ion binding, in its prediction. Predictions are presented for the activity coefficients of free-solvent for near-saturated protein solutions containing either bovine serum albumin or hemoglobin. As a verification step, the predictability of the model for the activity coefficient of sucrose solutions was evaluated. The predicted activity coefficients of free-solvent are compared to the calculated activity coefficients of free-solvent based on osmotic pressure data. It is observed that the predicted activity coefficients are increasingly dependent on the solute-solvent parameters as the protein concentration increases to near-saturation concentrations.

  19. Nutrient sequestration in Aquitaine lakes (SW France) limits nutrient flux to the coastal zone

    Science.gov (United States)

    Buquet, Damien; Anschutz, Pierre; Charbonnier, Céline; Rapin, Anne; Sinays, Rémy; Canredon, Axel; Bujan, Stéphane; Poirier, Dominique

    2017-12-01

    Oligotrophic coastal zones are disappearing from increased nutrient loading. The quantity of nutrients reaching the coast is determined not only by their original source (e.g. fertilizers used in agriculture, waste water discharges) and the land use, but also by the pathways through which nutrients are cycled from the source to the river mouth. In particular, lakes sequester nutrients and, hence, reduce downstream transfer of nutrients to coastal environments. Here, we quantify the impact of Aquitaine great lakes on the fluxes of dissolved macro-nutrients (N, P, Si) to the Bay of Biscay. For that, we have measured nutrient concentrations and fluxes in 2014 upstream and downstream lakes of Lacanau and Carcans-Hourtin, which belongs to the catchment of the Arcachon Bay, which is the largest coastal lagoon of the Bay of Biscay French coast. Data were compared to values obtained from the Leyre river, the main freshwater and nutrient source for the lagoon. Results show that processes in lakes greatly limit nutrient flux to the lagoon compared to fluxes from Leyre river, although the watershed is similar in terms of land cover. In lakes, phosphorus and silicon are trapped for long term in the sediment, silicon as amorphous biogenic silica and phosphorus as organic P and P associated with Fe-oxides. Nitrogen that enters lakes mostly as nitrate is used for primary production. N is mineralized in the sediment; a fraction diffuses as ammonium. N2 production through benthic denitrification extracts only 10% of dissolved inorganic nitrogen from the aquatic system. The main part is sequestered in organic-rich sediment that accumulates below 5 m depth in both lakes.

  20. Nutrient cycling, connectivity, and free-floating plant abundance in backwater lakes of the Upper Mississippi River

    Science.gov (United States)

    Houser, Jeff N.; Giblin, Shawn M.; James, William F.; Langrehr, H.A.; Rogala, James T.; Sullivan, John F.; Gray, Brian R.

    2013-01-01

    River eutrophication may cause the formation of dense surface mats of free floating plants (FFP; e.g., duckweeds and filamentous algae) which may adversely affect the ecosystem. We investigated associations among hydraulic connectivity to the channel, nutrient cycling, FFP, submersed aquatic vegetation (SAV), and dissolved oxygen concentration (DO) in ten backwater lakes of the Upper Mississippi River (UMR) that varied in connectivity to the channel. Greater connectivity was associated with higher water column nitrate (NO3-N) concentration, higher rates of sediment phosphorus (P) release, and higher rates of NO3-N flux to the sediments. Rates of sediment P and N (as NH4-N) release were similar to those of eutrophic lakes. Water column nutrient concentrations were high, and FFP tissue was nutrient rich suggesting that the eutrophic condition of the UMR often facilitated abundant FFP. However, tissue nutrient concentrations, and the associations between FFP biomass and water column nutrient concentrations, suggested that nutrients constrained FFP abundance at some sites. FFP abundance was positively associated with SAV abundance and negatively associated with dissolved oxygen concentration. These results illustrate important connections among hydraulic connectivity, nutrient cycling, FFP, SAV, and DO in the backwaters of a large, floodplain river.

  1. Modelling trends in soil solution concentrations under five forest-soil combinations in the Netherlands

    NARCIS (Netherlands)

    Salm, van der C.; Vries, de W.; Kros, J.

    1996-01-01

    The influence of forest and soil properties on changes in soil solution concentration upon a reduction deposition was examined for five forest-soil combinations with the dynamic RESAM model. Predicted concentrations decreased in the direction Douglas fir - Scotch pine - oak, due to decreased

  2. Standardisation of an European end-user nutrient database for nutritional epidemiology: what can we learn from the EPIC Nutrient Database (ENDB) project?

    DEFF Research Database (Denmark)

    Slimani, N.; Deharveng, G.; Unwin, I.

    2007-01-01

    the absence of a reference European nutrient database for international nutritional epidemiology studies, the EPIC Nutrient Database (ENDB) project has been set up to standardise nutrient databases (NDBs) across 10 European countries participating in the EPIC study. This paper reports the main...... problems in harmonising NDBs experienced by end-user in the ENDB project and the solutions adopted to prevent and minimize them, which are also relevant for other large European nutritional studies. Furthermore, it provides end-user recommendations for improving the comparability of European and other NDBs...

  3. Nutrient budgets for large Chinese estuaries

    Directory of Open Access Journals (Sweden)

    S. M. Liu

    2009-10-01

    Full Text Available Chinese rivers deliver about 5–10% of global freshwater input and 15–20% of the global continental sediment to the world ocean. We report the riverine fluxes and concentrations of major nutrients (nitrogen, phosphorus, and silicon in the rivers of the contiguous landmass of China and Korea in the northeast Asia. The rivers are generally enriched with dissolved inorganic nitrogen (DIN and depleted in dissolved inorganic phosphate (PO43− with very high DIN: PO43− concentration ratios. DIN, phosphorus, and silicon levels and loads in rivers are mainly affected by agriculture activities and urbanization, anthropogenic activities and adsorption on particulates, and rock types, climate and physical denudation intensity, respectively. Nutrient transports by rivers in the summer are 3–4 times higher than those in the winter with the exception of NH4+. The flux of NH4+ is rather constant throughout the year due to the anthropogenic sources such as the sewer discharge. As nutrient composition has changed in the rivers, ecosystems in estuaries and coastal sea have also changed in recent decades. Among the changes, a shift of limiting nutrients from phosphorus to nitrogen for phytoplankton production with urbanization is noticeable and in some areas silicon becomes the limiting nutrient for diatom productivity. A simple steady-state mass-balance box model was employed to assess nutrient budgets in the estuaries. The major Chinese estuaries export <15% of nitrogen, <6% of phosphorus required for phytoplankton production and ~4% of silicon required for diatom growth in the Chinese Seas (Bohai, Yellow Sea, East China Sea, South China Sea. This suggests that land-derived nutrients are largely confined to the immediate estuaries, and ecosystem in the coastal sea beyond the estuaries is mainly supported by other nutrient sources such as regeneration, open ocean and

  4. Specific wavelength colorimeter. [for measuring given solute concentration in test sample

    Science.gov (United States)

    Brawner, C. C.; Mcdavid, L. S.; Walsh, J. M. (Inventor)

    1974-01-01

    A self contained, specific wavelength, single beam colorimeter is described for direct spectrophotometric measurement of the concentration of a given solute in a test sample. An electrical circuit employing a photoconductive cell converts the optical output into a linear, directly readable meter output. The colorimeter is simple to operate and is adapted for use in zero gravity conditions. In a specific application, the colorimeter is designed to analyze the concentration of iodine in potable water carried aboard a space vehicle such as the 4B stage of Skylab.

  5. Development of a vinasse nutritive solution for hydroponics.

    Science.gov (United States)

    dos Santos, José Darcy; Lopes da Silva, André Luís; da Luz Costa, Jefferson; Scheidt, Gessiel Newton; Novak, Alessandra Cristine; Sydney, Eduardo Bittencourt; Soccol, Carlos Ricardo

    2013-01-15

    Vinasse is a residue that originates from the distillation of fuel alcohol. However, it contains a relative amount of nutrients. The aim of this work was to develop a nutritive solution using vinasse and to compare it with a commercial solution for the cultivation of lettuce, watercress and rocket. Vinasse obtained from juice must was decanted and filtered, followed by chemical analyses of the nutrients. A nutritive solution composed of 10% vinasse supplemented with nutrients was in agreement with the results of the chemical analyses (a similar amount of Furlani's solution). Experiments were then performed in an NFT (Nutrient film technique) system. The treatments used the vinasse solution and a commercial solution constituted from a Yara Fertilizantes(®) product. The height of the aerial part and the number of leaves of the crops were evaluated at 7, 14, 21, 28, 35 and 42 days. In most crops, the results were very similar. The vinasse solution promoted a larger number of leaves in lettuce and the highest aerial part in watercress. For the rocket, there were no significant differences between the two solutions. In conclusion, a nutritive solution was developed using vinasse, and this solution provided suitable growth, which was higher in some cases, for the crops studied herein. This study shows the great potential of this technology as a rational alternative to vinasse disposal. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Two-Phase Flow Modeling of Solid Dissolution in Liquid for Nutrient Mixing Improvement in Algal Raceway Ponds

    Directory of Open Access Journals (Sweden)

    Haider Ali

    2018-04-01

    Full Text Available Achieving optimal nutrient concentrations is essential to increasing the biomass productivity of algal raceway ponds. Nutrient mixing or distribution in raceway ponds is significantly affected by hydrodynamic and geometric properties. The nutrient mixing in algal raceway ponds under the influence of hydrodynamic and geometric properties of ponds is yet to be explored. Such a study is required to ensure optimal nutrient concentrations in algal raceway ponds. A novel computational fluid dynamics (CFD model based on the Euler–Euler numerical scheme was developed to investigate nutrient mixing in raceway ponds under the effects of hydrodynamic and geometric properties. Nutrient mixing was investigated by estimating the dissolution of nutrients in raceway pond water. Experimental and CFD results were compared and verified using solid–liquid mass transfer coefficient and nutrient concentrations. Solid–liquid mass transfer coefficient, solid holdup, and nutrient concentrations in algal pond were estimated with the effects of pond aspect ratios, water depths, paddle wheel speeds, and particle sizes of nutrients. From the results, it was found that the proposed CFD model effectively simulated nutrient mixing in raceway ponds. Nutrient mixing increased in narrow and shallow raceway ponds due to effective solid–liquid mass transfer. High paddle wheel speeds increased the dissolution rate of nutrients in raceway ponds.

  7. Critical zone structure controls concentration-discharge relationships and solute generation in forested tropical montane watersheds

    Science.gov (United States)

    Wymore, Adam S.; Brereton, Richard L.; Ibarra, Daniel E.; Maher, Kate; McDowell, William H.

    2017-07-01

    Concentration-discharge (C-Q) relationships are poorly known for tropical watersheds, even though the tropics contribute a disproportionate amount of solutes to the global ocean. The Luquillo Mountains in Puerto Rico offer an ideal environment to examine C-Q relationships across a heterogeneous tropical landscape. We use 10-30 years of weekly stream chemistry data across 10 watersheds to examine C-Q relationships for weathering products (SiO2(aq), Ca2+, Mg2+, and Na+) and biologically controlled solutes (dissolved organic carbon [DOC], dissolved organic nitrogen [DON], NH4+, NO3-, PO43-, K+, and SO42-). We analyze C-Q relationships using power law equations and a solute production model and use principal component analysis to test hypotheses regarding how the structure of the critical zone controls solute generation. Volcaniclastic watersheds had higher concentrations of weathering solutes and smaller tributaries were approximately threefold more efficient at generating these solutes than larger rivers. Lithology and vegetation explained a significant amount of variation in the theoretical maximum concentrations of weathering solutes (r2 = 0.43-0.48) and in the C-Q relationships of PO43- (r2 = 0.63) and SiO2(aq) (r2 = 0.47). However, the direction and magnitude of these relationships varied. Across watersheds, various forms of N and P displayed variable C-Q relationships, while DOC was consistently enriched with increasing discharge. Results suggest that PO43- may be a useful indicator of watershed function. Relationships between C-Q and landscape characteristics indicate the extent to which the structure and function of the Critical zone controls watershed solute fluxes.

  8. Sodium concentration in home made salt – sugar – solution (sss ...

    African Journals Online (AJOL)

    In a cohort of 210 young mothers, selected through cluster sampling technique from Ogida health district of Egor Local Government Area of Edo State, the electrolyte concentration of prepared salt-sugar-solutions (SSS) were evaluated. This was predicated on the need to determine the effects of introduction of various ...

  9. Growth and accumulation of carotenoids and nitrogen compounds in Gracilaria domingensis (Kütz. Sonder ex Dickie (Gracilariales, Rhodophyta cultured under different irradiance and nutrient levels

    Directory of Open Access Journals (Sweden)

    Fernanda Ramlov

    2011-05-01

    Full Text Available Effects of the interaction of irradiance and nutrient levels on growth and contents of photosynthetic pigments, carotenoids and proteins in Gracilaria domingensis (Kütz. Sonder ex Dickie (Gracilariales, Rhodophyta were investigated experimentally. Nutrient availability provided by dilutions of the nutrient solution of von Stosch (25 and 50%, which corresponded to nitrate concentrations of 125 and 250 μmol, respectively and two photon flux densities [low PFD (50±5 and high PFD (100±5 μmol photons.m-2.s-1] were tested. Growth rates of G. domingensis were stimulated by high PFD. The interaction between high nutrient availability (50% VSES and high PFD stimulated the accumulation of total soluble protein. Phycobiliprotein concentrations (phycoerythrin, phycocyanin, and allophycocyanin and carotenoid contents were influenced by irradiance levels. Phycobiliprotein concentrations were higher at low PFD and high irradiances stimulated carotenoid accumulation. These results reflect the function of these pigments in photoprotection and the acclimation of G. domingensis to changes in irradiance levels. Our results indicate that light is a limiting factor for G. domingensis growth, that variations in phycobiliprotein contents under different irradiance levels are related to photoacclimation process, and that higher carotenoid contents at high irradiances are due to a photoprotection mechanism.

  10. Growth and accumulation of carotenoids and nitrogen compounds in Gracilaria domingensis (Kütz. Sonder ex Dickie (Gracilariales, Rhodophyta cultured under different irradiance and nutrient levels

    Directory of Open Access Journals (Sweden)

    Fernanda Ramlov

    2011-04-01

    Full Text Available Effects of the interaction of irradiance and nutrient levels on growth and contents of photosynthetic pigments, carotenoids and proteins in Gracilaria domingensis (Kütz. Sonder ex Dickie (Gracilariales, Rhodophyta were investigated experimentally. Nutrient availability provided by dilutions of the nutrient solution of von Stosch (25 and 50%, which corresponded to nitrate concentrations of 125 and 250 μmol, respectively and two photon flux densities [low PFD (50±5 and high PFD (100±5 μmol photons.m-2.s-1] were tested. Growth rates of G. domingensis were stimulated by high PFD. The interaction between high nutrient availability (50% VSES and high PFD stimulated the accumulation of total soluble protein. Phycobiliprotein concentrations (phycoerythrin, phycocyanin, and allophycocyanin and carotenoid contents were influenced by irradiance levels. Phycobiliprotein concentrations were higher at low PFD and high irradiances stimulated carotenoid accumulation. These results reflect the function of these pigments in photoprotection and the acclimation of G. domingensis to changes in irradiance levels. Our results indicate that light is a limiting factor for G. domingensis growth, that variations in phycobiliprotein contents under different irradiance levels are related to photoacclimation process, and that higher carotenoid contents at high irradiances are due to a photoprotection mechanism.

  11. Optimal nutrient application strategy for bioremediation of oil-polluted beaches. Volume 1

    International Nuclear Information System (INIS)

    Li, H.; Zhao, Q.; Boufadel, M.C.; Venosa, A.D.

    2007-01-01

    Offshore oil spills in coastal areas generally occur in the intertidal zone of beaches and affect the top 25 cm of soil, known as the bioremediation zone. Biostimulation by nutrient application such as nitrogen and phosphorus is a viable technology for restoring oil-contaminated beaches. The key for achieving a rapid cost-effective cleanup is to ensure maximum nutrient residence time. This study proposed a strategy that consisted of injecting nutrients through a perforated pipe at the high tide line. Beach hydraulics were numerically simulated to estimate the optimal injection flow rate of nutrient solution. It was shown that the optimal application should begin following high tide just as it drops and should last for half a tidal cycle. The flow rate ensures that the saturated wet-front of the nutrient solution on the beach surface moves seaward with the same speed of the falling tide keeping a constant distance with the tide line. The numerical results were generalized to a broad range of hydraulic and tidal properties of beaches using an innovative dimensionless formulation for water flow and solute transport in porous media. Nomographs were presented to provide the flow rate based on 4 parameters, notably the beach slope, permeability, tidal amplitude and tidal period. 29 refs., 1 tab., 5 figs

  12. A path-independent integral for the characterization of solute concentration and flux at biofilm detachments

    Science.gov (United States)

    Moran, B.; Kulkarni, S.S.; Reeves, H.W.

    2007-01-01

    A path-independent (conservation) integral is developed for the characterization of solute concentration and flux in a biofilm in the vicinity of a detachment or other flux limiting boundary condition. Steady state conditions of solute diffusion are considered and biofilm kinetics are described by an uptake term which can be expressed in terms of a potential (Michaelis-Menten kinetics). An asymptotic solution for solute concentration at the tip of the detachment is obtained and shown to be analogous to that of antiplane crack problems in linear elasticity. It is shown that the amplitude of the asymptotic solution can be calculated by evaluating a path-independent integral. The special case of a semi-infinite detachment in an infinite strip is considered and the amplitude of the asymptotic field is related to the boundary conditions and problem parameters in closed form for zeroth and first order kinetics and numerically for Michaelis-Menten kinetics. ?? Springer Science+Business Media, Inc. 2007.

  13. Complete nutrient recovery from source-separated urine by nitrification and distillation.

    Science.gov (United States)

    Udert, K M; Wächter, M

    2012-02-01

    In this study we present a method to recover all nutrients from source-separated urine in a dry solid by combining biological nitrification with distillation. In a first process step, a membrane-aerated biofilm reactor was operated stably for more than 12 months, producing a nutrient solution with a pH between 6.2 and 7.0 (depending on the pH set-point), and an ammonium to nitrate ratio between 0.87 and 1.15 gN gN(-1). The maximum nitrification rate was 1.8 ± 0.3 gN m(-2) d(-1). Process stability was achieved by controlling the pH via the influent. In the second process step, real nitrified urine and synthetic solutions were concentrated in lab-scale distillation reactors. All nutrients were recovered in a dry powder except for some ammonia (less than 3% of total nitrogen). We estimate that the primary energy demand for a simple nitrification/distillation process is four to five times higher than removing nitrogen and phosphorus in a conventional wastewater treatment plant and producing the equivalent amount of phosphorus and nitrogen fertilizers. However, the primary energy demand can be reduced to values very close to conventional treatment, if 80% of the water is removed with reverse osmosis and distillation is operated with vapor compression. The ammonium nitrate content of the solid residue is below the limit at which stringent EU safety regulations for fertilizers come into effect; nevertheless, we propose some additional process steps that will increase the thermal stability of the solid product. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Late gestational nutrient restriction

    DEFF Research Database (Denmark)

    Tygesen, Malin Plumhoff; Nielsen, Mette Olaf; Nørgaard, Peder

    2008-01-01

    We investigated the effect of 50% nutrient restriction during the last 6 weeks of gestation on twin-pregnant ewes' plasma glucose, non-esterified fatty acid, ß-hydroxybutyrate, insulin, IGF-1 and leptin concentrations and the effects on lamb birth weight and ewes' lactation performance. Plasma...

  15. Metrological assessment of TDR performance for measurement of potassium concentration in soil solution

    Directory of Open Access Journals (Sweden)

    Isaac de M. Ponciano

    2016-04-01

    Full Text Available ABSTRACT Despite the growing use of the time domain reflectometry (TDR technique to monitoring ions in the soil solution, there are few studies that provide insight into measurement error. To overcome this lack of information, a methodology, based on the central limit theorem error, was used to quantify the uncertainty associated with using the technique to estimate potassium ion concentration in two soil types. Mathematical models based on electrical conductivity and soil moisture derived from TDR readings were used to estimate potassium concentration, and the results were compared to potassium concentration determined by flame spectrophotometry. It was possible to correct for random and systematic errors associated with TDR readings, significantly increasing the accuracy of the potassium estimation methodology. However, a single TDR reading can lead to an error of up to ± 18.84 mg L-1 K+ in soil solution (0 to 3 dS m-1, with a 95.42% degree of confidence, for a loamy sand soil; and an error of up to ± 12.50 mg L-1 of K+ (0 to 2.5 dS m-1 in soil solution, with a 95.06% degree of confidence, for a sandy clay soil.

  16. Relations of biological indicators to nutrient data for lakes and streams in Pennsylvania and West Virginia, 1990-98

    Science.gov (United States)

    Brightbill, Robin A.; Koerkle, Edward H.

    2003-01-01

    The Clean Water Action Plan of 1998 provides a blueprint for federal agencies to work with states, tribes, and other stakeholders to protect and restore the Nation's water resources. The plan includes an initiative that addresses the nutrient-enrichment problem of lakes and streams across the United States. The U.S. Environmental Protection Agency (USEPA) is working to set nutrient criteria by nationwide nutrient ecoregions that are an aggregation of the Omernik level III ecoregions. Because low levels of nutrients are necessary for healthy streams and elevated concentrations can cause algal blooms that deplete available oxygen and kill off aquatic organisms, criteria levels are to be set, in part, using the relation between chlorophyll a and concentrations of total nitrogen and total phosphorus.Data from Pennsylvania and West Virginia, collected between 1990 and 1998, were analyzed for relations between chlorophyll a, nutrients, and other explanatory variables. Both phytoplankton and periphyton chlorophyll a concentrations from lakes and streams were analyzed separately within each of the USEPA nutrient ecoregions located within the boundaries of the two states. These four nutrient ecoregions are VII (Mostly Glaciated Dairy), VIII (Nutrient Poor, Largely Glaciated Upper Midwest and Northeast), IX (Southeastern Temperate Forested Plains and Hills), and XI (Central and Eastern Forested Uplands).Phytoplankton chlorophyll a concentrations in lakes were related to total nitrogen, total phosphorus, Secchi depth, concentration of dissolved oxygen, pH, water temperature, and specific conductivity. In nutrient ecoregion VII, nutrients were not significant predictors of chlorophyll a concentrations. Total nitrogen, Secchi depth, and pH were significantly related to phytoplankton chlorophyll a concentrations in nutrient ecoregion IX. Lake periphyton chlorophyll a concentrations from nutrient ecoregion XI were related to total phosphorus rather than total nitrogen, Secchi

  17. ELECTRODIALYSIS IN THE CONVERSION STEP OF THE CONCENTRATED SALT SOLUTIONS IN THE PROCESS OF BATTERY SCRAP

    Directory of Open Access Journals (Sweden)

    S. I. Niftaliev

    2014-01-01

    Full Text Available Summary. The concentrated sodium sulfate solution is formed during the processing of waste battery scrap. A promising way to further treatment of the concentrated salt solution could be the conversion of these salts into acid and bases by electrodialysis, that can be reused in the same technical process cycle. For carrying out the process of conversion of salts into the corresponding acid and base several cells schemes with different combinations of cation, anion and bipolar membranes are used. At this article a comparative analysis of these cells is carried out. In the cells there were used the membranes МC-40, МА-41 and МB-2I. Acid and base solutions with higher concentration may be obtained during the process of electrodialysis in the circulation mode, when a predetermined amount of salt in the closed loop is run through a set of membranes to obtain the desired concentration of the product. The disadvantages of this method are the high cost of buffer tanks and the need to work with small volumes of treated solutions. In industrial applications it is advisable to use continuous electrodialysis with bipolar membranes, since this configuration allows to increase the number of repeating sections, which is necessary to reduce the energy costs. The increase of the removal rate of salts can be achieved by increasing the process steps, and to produce a more concentrated products after the conversion step can be applied electrodialysis-concentrator or evaporator.

  18. Distribution of nutrients in the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    De; Naqvi, S.W.A; Reddy, C.V.G.

    and low nutrient concentrations increased in thickness from north to south. The intermediate water layer was marked by a steep rise of nutrients associated with oxygen minimum suggesting active decomposition of organic matter.N:P in the upper 75 m...

  19. Determination of the thermodynamic state of concentrated hemoglobin solutions by means of small angle X-ray scattering

    International Nuclear Information System (INIS)

    Zinke, M.

    1979-01-01

    Exemplified by hemoglobin, the thermodynamic equilibrium properties of the dissolved macromolecular system could be determined solely from the small angle X-ray scattering of concentrated macromolecular solutions via the intermolecular structure of the dissolved macromolecules and their intermolecular potentials. From the scattering experiment on concentrated Hb solutions the concentration dependence of the following properties of the dissolved Hb system were determined: fluctuation, isothermic compressibility, internal energy, surface tension, and osmotic pressure. (author)

  20. Zinc deficiency in field-grown pecan trees: changes in leaf nutrient concentrations and structure.

    Science.gov (United States)

    Ojeda-Barrios, Dámaris; Abadía, Javier; Lombardini, Leonardo; Abadía, Anunciación; Vázquez, Saúl

    2012-06-01

    Zinc (Zn) deficiency is a typical nutritional disorder in pecan trees [Carya illinoinensis (Wangenh.) C. Koch] grown under field conditions in calcareous soils in North America, including northern Mexico and south-western United States. The aim of this study was to assess the morphological and nutritional changes in pecan leaves affected by Zn deficiency as well as the Zn distribution within leaves. Zinc deficiency led to decreases in leaf chlorophyll concentrations, leaf area and trunk cross-sectional area. Zinc deficiency increased significantly the leaf concentrations of K and Ca, and decreased the leaf concentrations of Zn, Fe, Mn and Cu. All nutrient values found in Zn-deficient leaves were within the sufficiency ranges, with the only exception of Zn, which was approximately 44, 11 and 9 µg g(-1) dry weight in Zn-sufficient, moderately and markedly Zn-deficient leaves, respectively. Zinc deficiency led to decreases in leaf thickness, mainly due to a reduction in the thickness of the palisade parenchyma, as well as to increases in stomatal density and size. The localisation of Zn was determined using the fluorophore Zinpyr-1 and ratio-imaging technique. Zinc was mainly localised in the palisade mesophyll area in Zn-sufficient leaves, whereas no signal could be obtained in Zn-deficient leaves. The effects of Zn deficiency on the leaf characteristics of pecan trees include not only decreases in leaf chlorophyll and Zn concentrations, but also a reduction in the thickness of the palisade parenchyma, an increase in stomatal density and pore size and the practical disappearance of Zn leaf pools. These characteristics must be taken into account to design strategies to correct Zn deficiency in pecan tree in the field. Copyright © 2012 Society of Chemical Industry.

  1. Glacier Melting Increases the Solute Concentrations of Himalayan Glacial Lakes.

    Science.gov (United States)

    Salerno, Franco; Rogora, Michela; Balestrini, Raffaella; Lami, Andrea; Tartari, Gabriele A; Thakuri, Sudeep; Godone, Danilo; Freppaz, Michele; Tartari, Gianni

    2016-09-06

    Over the past two decades, we observed a substantial rise in ionic content that was mainly determined by the sulfate concentration at 20 remote high elevation lakes located in central southern Himalaya. At LCN9, which was monitored on an annual basis for the last 20 years, the sulfate concentrations increased over 4-fold. Among the main causes, we exclude a change in the composition of wet atmospheric deposition, as well as a possible influence of decrease in seasonal snow cover duration, which could have exposed larger basin surfaces to alteration processes. Glacier retreat likely was the main factor responsible for the observed increase of sulfate concentrations. We attribute this chemical changes mainly to the sulfide oxidation processes that occur in subglacial environments. Moreover, we observe that the weakened monsoon of the past two decades has only partially contributed to the lakes enrichment through runoff waters that are more concentrated in solutes or lowering the water table, resulting in more rock exposed to air and enhanced mineral oxidation.

  2. [Computer modeling the dependences of the membrane potential for polymeric membrane separated non-homogeneous electrolyte solutions on concentration Rayleigh number].

    Science.gov (United States)

    Slezak, Izabella H; Jasik-Slezak, Jolanta; Bilewicz-Wyrozumska, Teresa; Slezak, Andrzej

    2006-01-01

    On the basis of model equation describing the membrane potential delta psi(s) on concentration Rayleigh number (R(C)), mechanical pressure difference (deltaP), concentration polarization coefficient (zeta s) and ratio concentration of solutions separated by membrane (Ch/Cl), the characteristics delta psi(s) = f(Rc)(delta P, zeta s, Ch/Cl) for steady values of zeta s, R(C) and Ch/Cl in single-membrane system were calculated. In this system neutral and isotropic polymeric membrane oriented in horizontal plane, the non-homogeneous binary electrolytic solutions of various concentrations were separated. Nonhomogeneity of solutions is results from creations of the concentration boundary layers on both sides of the membrane. Calculations were made for the case where on a one side of the membrane aqueous solution of NaCl at steady concentration 10(-3) mol x l(-1) (Cl) was placed and on the other aqueous solutions of NaCl at concentrations from 10(-3) mol x l(-1) to 2 x 10(-2) mol x l(-1) (Ch). Their densities were greater than NaCl solution's at 10(-3) mol x l(-1). It was shown that membrane potential depends on hydrodynamic state of a complex concentration boundary layer-membrane-concentration boundary layer, what is controlled by deltaP, Ch/Cl, Rc and Zeta(s).

  3. Improving fermented quality of cider vinegar via rational nutrient feeding strategy.

    Science.gov (United States)

    Qi, Zhengliang; Dong, Die; Yang, Hailin; Xia, Xiaole

    2017-06-01

    This work aimed to find a rational nutrient feeding strategy for cider vinegar fermentation based on adequate information on the nutritional requirement of acetic acid bacteria. Through single nutrient lack experiment assay, necessary nutrient recipe for Acetobacter pasteurianus CICIM B7003 in acetous fermentation was confirmed. Compounds from the essential nutrient recipe were tested further to find out the key substrates significantly influencing cider vinegar fermentation. The findings showed that aspartate, glutamate, proline and tryptophan should be considered in detail for optimizing nutritional composition of cider. Finally, a nutrient feeding strategy that simultaneously adds proline, glutamate, aspartate and tryptophan to form final concentrations of 0.02g/L, 0.03g/L, 0.01g/L and 0.005g/L in cider was achieved by orthogonal experiment design. Comparing to the original fermentation, the yield of acetic acid from alcohol reached 93.3% and the concentration of most volatile flavor compounds increased with the rational nutrient feeding strategy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Effect of uranyl nitrate and free acid concentration in feed solution of gelation on UO2 kernel quality

    International Nuclear Information System (INIS)

    Masduki, B.; Wardaya; Widarmoko, A.

    1996-01-01

    An investigation on the effect of uranium and free nitric acid concentration of uranyl nitrate as feed of gelation process on quality of UO 2 kernel was done.The investigation is to look for some concentration of uranyl nitrate solutions those are optimum as feed for preparation of gelled UO 3 . Uranyl nitrate solution of various concentration of uranium (450; 500; 550; 600; 650; 700 g/l) and free nitric acid of (0.9; 1.0; 1.1 N) was made into feed solutions by adding urea and HMTA with mole ratio of urea/uranium and HMTA/uranium 2.1 and 2.0. The feed solutions were changed into spherical gelled UO 3 by dropping was done to get the optimum concentrations of uranyl nitrate solutions. The gelled UO 3 was soaked and washed with 2.5% ammonia solution for 17 hours, dried at 70 o C, calcined at 350 o C for 3 hours then reduced at 850 o C for 3 hours. At every step of the steps process the colour and percentage of well product of gelled UO 3 were noticed. The density and O/U ratio of end product (UO 2 kernel) was determined, the percentage of well product of all steps process was also determined. The three factor were used to chose the optimum concentration of uranyl nitrate solution. From this investigation it was concluded that the optimum concentration of uranyl nitrate was 600 g/l uranium with free nitric acid 0,9 - 1,0 N, the percentage of well product was 97% density of 6.12 - 4.8 g/cc and O/U ratio of 2.15 - 2.06. (author)

  5. In-core LOCA-s: analytical solution for the delayed mixing model for moderator poison concentration

    International Nuclear Information System (INIS)

    Firla, A.P.

    1995-01-01

    Solutions to dynamic moderator poison concentration model with delayed mixing under single pressure tube / calandria tube rupture scenario are discussed. Such a model is described by a delay differential equation, and for such equations the standard ways of solution are not directly applicable. In the paper an exact, direct time-domain analytical solution to the delayed mixing model is presented and discussed. The obtained solution has a 'marching' form and is easy to calculate numerically. Results of the numerical calculations based on the analytical solution indicate that for the expected range of mixing times the existing uniform mixing model is a good representation of the moderator poison mixing process for single PT/CT breaks. However, for postulated multi-pipe breaks ( which is very unlikely to occur ) the uniform mixing model is not adequate any more; at the same time an 'approximate' solution based on Laplace transform significantly overpredicts the rate of poison concentration decrease, resulting in excessive increase in the moderator dilution factor. In this situation the true, analytical solution must be used. The analytical solution presented in the paper may also serve as a bench-mark test for the accuracy of the existing poison mixing models. Moreover, because of the existing oscillatory tendency of the solution, special care must be taken in using delay differential models in other applications. (author). 3 refs., 3 tabs., 8 figs

  6. Deactivation and treatment of mine wastewaters and of aqueous solutions discharged in uranium ore treatment and processing

    International Nuclear Information System (INIS)

    Jilek, R.; Prochazka, H.; Fuska, J.; Nemec, P.; Katzer, J.

    1974-01-01

    A description is presented of decontamination and purification of mine wastewaters and water solutions discharged from uranium ore treatment and processing and of the simultaneous removal and concentration of uranium-radium daughters, mainly of 226 Ra and 210 Pb. These elements are incorporated in the mycelium of microorganisms, such as those of the Fungi imperfecti class or are sorbed on the mycelium surface. The mycelia are then mechanically separated from the decontaminated solution, e.g., by filtration, centrifugation or sedimentation. The mycelium may be cultivated in the purified solutions to which nutrients are added, such as carbon, nitrogen and phosphorus in concentrations necessary for the growth of the microorganisms used. The mycelium may be added to the purified solution either in the native or in the dried state. (B.S.)

  7. Fitotoxidez de cádmio para Eucalyptus maculata e E. urophylla em solução nutritiva Cadmium phytotoxity to Eucalyptus maculata and E. urophylla in nutrient solution

    Directory of Open Access Journals (Sweden)

    Cláudio Roberto Fonsêca Sousa Soares

    2005-04-01

    Full Text Available Estudaram-se os efeitos de doses crescentes de Cd em solução nutritiva no crescimento e absorção mineral de mudas de Eucalyptus maculata e E. urophylla e respectivos sintomas de fitotoxidez em casa de vegetação. Mudas foram mantidas por cinco semanas em vasos contendo 2 L de solução nutritiva de Clark, adicionando-se 0, 45, 90, 135 e 180 miM de Cd fornecido como CdSO4. Após uma semana de exposição aos tratamentos, E. maculata exibiu pontuações avermelhadas nas nervuras, clorose internerval, necrose, murchamento das folhas e escurecimento das raízes. Além desses sintomas, E. urophylla apresentou morte das gemas apicais e acentuada queda de folhas. A dose crítica de Cd para reduzir em 10% a matéria seca da parte aérea foi baixa; 2,4 miM e 1,5 miM de Cd para E. maculata e E. urophylla, respectivamente. Os níveis críticos de toxidez na parte aérea foram de 14,5 mg kg-1 em E. maculata e 10,8 mg kg-1 de Cd em E. urophylla. Esses resultados indicaram que E. maculata é provavelmente menos sensível ao Cd do que E. urophylla. Foi também observado que o Cd reduziu a translocação de Cu em até 24 e 43% em E. maculata e E. urophylla, respectivamente. A translocação de Fe caiu de 36% em média, nas duas espécies no controle para apenas 12% com 180 miM Cd. A elevação nas doses de Cd reduziu os teores de Ca e Mg na parte aérea das espécies, atingindo-se teores de Mg abaixo da faixa considerada adequada em E. urophylla. Ficaram evidenciadas a fitotoxidez de Cd no Eucalyptus e a relação desta com a diminuição da translocação de Cu e Fe e com a diminuição dos teores foliares de Mg.The effects of increasing concentration of Cd in nutrient solution on growth, mineral uptake and phytotoxicity symptoms in Eucalyptus maculata and E. urophylla seedlings were studied under greenhouse conditions. Seedlings were kept for five weeks in 2 L pots containing Clark's nutrient solution amended with 0, 45, 90, 135 and 180 muM as CdSO4

  8. Simultaneous determination of nitric acid and uranium concentrations in aqueous solution from measurements of electrical conductivity, density, and temperature

    International Nuclear Information System (INIS)

    Spencer, B.B.

    1991-01-01

    Nuclear fuel reprocessing plants handle aqueous solutions of nitric acid and uranium in large quantities. Automatic control of process operations requires reliable measurements of these solutes concentration, but this is difficult to directly measure. Physical properties such as solution density and electrical conductivity vary with solute concentration and temperature. Conductivity, density and temperature can be measured accurately with relatively simple and inexpensive devices. These properties can be used to determine solute concentrations will good correlations. This paper provides the appropriate correlations for solutions containing 2 to 6 Molar (M) nitric acid and 0 to 300 g/L uranium metal at temperatures from 25--90 degrees C. The equations are most accurate below 5 M nitric acid, due to a broad maximum in the conductivity curve at 6 M. 12 refs., 9 figs., 6 tabs

  9. Effect of Na2CO3 degumming concentration on LiBr-formic acid-silk fibroin solution properties

    Directory of Open Access Journals (Sweden)

    Liu Zhi

    2016-01-01

    Full Text Available Salt-acid system has been proved to be of high efficiency for silk fibroin dissolution. Using salt-acid system to dissolve silk, native silk fibrils can be preserved in the regenerated solution. Increasing experiments indicate that acquirement of silk fibrils in solution is strongly associated with the degumming process. In this study, the effect of sodium carbonate degumming concentration on solution properties based on lithium bromide-formic acid dissolution system was systematically investigated. Results showed that the morphology transformation of silk fibroin in solution from nanospheres to nanofibrils is determined by sodium carbonate concentration during the degumming process. Solutions containing different silk fibroin structure exhibited different rheological behaviors and different electrospinnability, leading to different electrospun nanofibre properties. The results have guiding significance for preparation and application of silk fibroin solutions.

  10. Application of refractometry to quality assurance monitoring of parenteral nutrition solutions.

    Science.gov (United States)

    Chang, Wei-Kuo; Chao, You-Chen; Yeh, Ming-Kung

    2008-01-01

    Parenteral nutrition (PN) solution contains various concentrations of dextrose, amino acids, lipids, vitamins, electrolytes, and trace elements. Incorrect preparation of PN solution could lead to patient death. In this study we used the refractive index as a quality assurance tool to monitor the preparation of PN solution. Refractive indices of single nutrient components and PN solutions consisting of various concentrations of dextrose, amino acids, electrolytes, and lipids were measured. A mathematical equation and its linear plot were generated then used to predict the refractive index of the PN solution. The best-fit refractive index for PN solution (i.e., the predicted refractive index)=0.9798x(% dextrose)+1.2889x(% amino acids)+1.1017x(% lipids)+0.9440x(% sum of the electrolytes)+0.5367 (r2=0.99). This equation was validated by comparing the measured refractive indices of 500 clinical PN solutions to their predicted refractive indices. We found that 2 of the 500 prepared samples (0.4%) had less than the predicted refractive index (<95%). Refractive index can be used as a reliable quality assurance tool for monitoring PN preparation. Such information can be obtained at the bedside and used to confirm the accuracy of the PN solution composition.

  11. Growth and physiological responses to water and nutrient stress in ...

    African Journals Online (AJOL)

    Growth and physiological responses to water and nutrient stress in oil palm. ... changes in growth, physiology and nutrient concentration in response to two watering regimes (well-watered and water-stress conditions) and ... from 32 Countries:.

  12. Modelling nutrient cycling in forest ecosystems; Modellering av naeringssyklus i skogoekosystemer

    Energy Technology Data Exchange (ETDEWEB)

    Kvindesland, Sheila H.S.B.

    1997-12-31

    Acid deposition`s threat to fresh water and forest environments became an issue in the late 1960s. Acid deposition and forest nutrient cycling then began to be researched in greater co-operation. This thesis studies nutrient cycling processes in Norway spruce forests, emphasizing the effects on soil chemical properties, soil solution chemistry and streamwater chemistry. It investigates the effects of different aged stands on nutrient cycling and sets up nutrient budgets of the base cations and nitrogen at two sites in Norway. It also selects, documents, calibrates, tests and improves nutrient cycling models for use in Norwegian forests. 84 refs., 44 figs., 46 tabs.

  13. Structure Manipulation of Carbon Aerogels by Managing Solution Concentration of Precursor and Its Application for CO2 Capture

    Directory of Open Access Journals (Sweden)

    Pingping He

    2018-04-01

    Full Text Available A series of carbon aerogels were synthesized by polycondensation of resorcinol and formaldehyde, and their structure was adjusted by managing solution concentration of precursors. Carbon aerogels were characterized by X-ray diffraction (XRD, Raman, Fourier transform infrared spectroscopy (FTIR, N2 adsorption/desorption and scanning electron microscope (SEM technologies. It was found that the pore structure and morphology of carbon aerogels can be efficiently manipulated by managing solution concentration. The relative micropore volume of carbon aerogels, defined by Vmicro/Vtol, first increased and then decreased with the increase of solution concentration, leading to the same trend of CO2 adsorption capacity. Specifically, the CA-45 (the solution concentration of precursors is 45 wt% sample had the highest CO2 adsorption capacity (83.71 cm3/g and the highest selectivity of CO2/N2 (53 at 1 bar and 0 °C.

  14. Structural study of concentrated micellar solutions

    International Nuclear Information System (INIS)

    Zemb, Thomas

    1985-01-01

    This research thesis reports the study of the structure of concentrated soap-water binary micelles with a comparison of measurements of light, neutrons and X-ray scattering, and the relaxation induced by paramagnetic ions adsorbed at the interface. In the first part, the author discusses the specific sensitivity ranges of different experimental techniques, outlines the resolution which can be obtained with scattering experiments, and proposes a critical analysis of results published in the relevant literature. In a second part, the author discusses the compared results of the application of various techniques (magnetic resonance, X-light and neutron scattering) on the two most used model systems: sodium octanoate and sodium dodecyl sulfate (SDS) in solution. Then, the author addresses the case of ternary systems: study of the influence of the presence of a co-surfactant on the structure, study of the effect of interfacial charge on the micellar structure, use of the same previous quantitative methods to study the disturbances brought to the structure due to the presence of reactants [fr

  15. Effect of Ni and Urea on Growth, Nitrate and Nutrients Concentration in Lettuce (Lactuca sativa Grown in Hydroponics

    Directory of Open Access Journals (Sweden)

    Hosein Nazari Mamaqani

    2017-02-01

    Full Text Available Introduction: The N source used in commercial hydroponic culture of vegetables is mainly NO3-N. The rate of NO3- uptake is usually high, particularly in leafy vegetables and it can be markedly increased when the NO3- supply in the environment is high. An abundant N supply leads to a high NO3-N absorption and accumulation in plants. When NO3- rich vegetables are consumed, various harmful effects on human health may occur such as met-hemoglobinemia (Blue Baby Syndrome and cancer. Keeping levels of NO3- below limits of FAO seems to be impossible without changing conventional fertilizer application techniques. The suitability of urea for the cultivation of field crops has been well documented. Urea is used as the main source of N fertilizer for crops grown in soil. Its use as N source for crops grown under the hydroponic system has yet to be evaluated. To hydrolyze urea, the enzyme urease requires Ni as a component. Substitution of urea for commonly used N03-N fertilizers in hydroponic culture of vegetables would not only enable to avoid excessive accumulation of N03- in plants but would also reduce the cost of production. Leafy vegetable crops, such as lettuce and spinach, contain large amounts of N03-N. Therefore, it is important to reduce N03- concentrations in hydroponically grown with lowest negative effects on yield. Materials and Methods: The experiments were carried outin greenhouse hydroponicsResearchFaculty of Agriculture, University of Tabriz in randomized complete block designwithtwo factors ureaatfivelevels of 0,25, 50, 75and100milligrams perliter(U0, U25,U50, U75, U100andnickelattwo levels of0and2mg per liter (Ni0, Ni2ofnickelsulfate(NiSO4in4replicatesusinglettuce(Lactuca sativa cv. Siyahoo. Plants fed with the modifiedHoagland solutionorhalf theconcentration. Treatments added to nutrient solution when plants were in four leaf stage. Plants were harvested 50 days after treatment. Different organs (leaves, stems and roots were separated

  16. Mudas de melancia produzidas com substrato à base de pó de coco e soluções nutritivas Watermelon seedlings produced with coconut powder and nutrient solutions

    Directory of Open Access Journals (Sweden)

    Anamaria RP Ramos

    2012-06-01

    mudas de melancia, em relação ao crescimento e status nutricional.The choice of substrate is one of the most important stages for the seedlings production and must take into account the nutritional requirements of cultivated species. Thus, the objective was to evaluate the substrate using coconut dust associated with nutrient solutions to produce seedlings of watermelon. The experiment was carried out at Embrapa Semi-Arid in Petrolina, Pernambuco state, Brazil, in a greenhouse in a completely randomized design with ten replications in a factorial arrangement 2 x 10 (cultivars of watermelon and substrates. The cultivars used were: Opara and Top Gun. The coconut fiber was associated with nutrient solutions as follows: T1= control treatment composed of the commercial organic substrate Plantmax® (SC, T2= coconut powder (PC, T3= coconut powder + melon solution (PC+SM, T4= coconut powder + solution of Hoagland and Arnon 12.5% (12.5% PC+HS, T5= coconut powder + solution of Hoagland and Arnon 25% (PC+HS 25%, T6= coconut powder + solution of Hoagland and Arnon 50% (PC+HS 50%, T7= coconut powder + solution of Hoagland and Arnon 75% (PC+HS 75%, T8= coconut powder + solution of Hoagland and Arnon 100% (100% PC+HS, T9= coconut powder + Aminoagro Mol (PC+AM, T10= coconut powder Aminoagro Root (PC+AR. The solutions were applied eight times, 10 mL on each application, since the fourth day after sowing date (DAS, when the evaluation of seedlings emergence began. At 24 DAS we evaluated the fresh weight of shoots and roots, root length, number of roots in the upper third and contents of macro and micronutrients in the aboveground part. The cv. Top Gun presented higher levels of nutrients, except for iron and copper. The treatments T6, T7 and T8 presented levels of nutrients in plants similar to the commercial substrate Plantmax. In general, the combinations of coconut dust associated with the nutrient solution of Hoagland and Arnon at 50, 75 and 100% and Aminoagro Root proved to be

  17. Extraction of soil solution by drainage centrifugation-effects of centrifugal force and time of centrifugation on soil moisture recovery and solute concentration in soil moisture of loess subsoils.

    Science.gov (United States)

    Fraters, Dico; Boom, Gerard J F L; Boumans, Leo J M; de Weerd, Henk; Wolters, Monique

    2017-02-01

    The solute concentration in the subsoil beneath the root zone is an important parameter for leaching assessment. Drainage centrifugation is considered a simple and straightforward method of determining soil solution chemistry. Although several studies have been carried out to determine whether this method is robust, hardly any results are available for loess subsoils. To study the effect of centrifugation conditions on soil moisture recovery and solute concentration, we sampled the subsoil (1.5-3.0 m depth) at commercial farms in the loess region of the Netherlands. The effect of time (20, 35, 60, 120 and 240 min) on recovery was studied at two levels of the relative centrifugal force (733 and 6597g). The effect of force on recovery was studied by centrifugation for 35 min at 117, 264, 733, 2932, 6597 and 14,191g. All soil moisture samples were chemically analysed. This study shows that drainage centrifugation offers a robust, reproducible and standardised way for determining solute concentrations in mobile soil moisture in silt loam subsoils. The centrifugal force, rather than centrifugation time, has a major effect on recovery. The maximum recovery for silt loams at field capacity is about 40%. Concentrations of most solutes are fairly constant with an increasing recovery, as most solutes, including nitrate, did not show a change in concentration with an increasing recovery.

  18. Relationships between nutrients and chlorophyll a concentration in the international Alma Gol Wetland, Iran

    Directory of Open Access Journals (Sweden)

    Saeed Balali

    2013-05-01

    Full Text Available This study investigated the relationships between nutrients and chlorophyll, a concentration in the International Alma Gol Wetland. Chlorophyll a is the major photosynthetic pigment in lots of phytoplanktons and has been used as a trophy index in aquatic ecosystems. Water samples were collected fortnightly from five stations in the wetland during summer and autumn. Chlorophyll-a ranged between 4.38 to 156.55 mg/m3, sulfate ranged between 138 to 190 mg/l, total alkalinity ranged between 80 to 280 mg/l, silica ranged between 3.80 to 35.00 mg/l, phosphate ranged between 0.02 to 3.70 mg/l, ammonia ranged between 0.10 to 11.90 mg/l, nitrate ranged between 0.01 to 2.75 mg/l and nitrite ranged between 0.01 to 0.39 mg/l. There was a significant correlation between chlorophyll a and nitrate, nitrite and ammonia but there was no significant correlation between chlorophyll a and silica, total alkalinity, sulfate and phosphorus.

  19. Nutrient Shielding in Clusters of Cells

    Science.gov (United States)

    Lavrentovich, Maxim O.; Koschwanez, John H.; Nelson, David R.

    2014-01-01

    Cellular nutrient consumption is influenced by both the nutrient uptake kinetics of an individual cell and the cells’ spatial arrangement. Large cell clusters or colonies have inhibited growth at the cluster's center due to the shielding of nutrients by the cells closer to the surface. We develop an effective medium theory that predicts a thickness ℓ of the outer shell of cells in the cluster that receives enough nutrient to grow. The cells are treated as partially absorbing identical spherical nutrient sinks, and we identify a dimensionless parameter ν that characterizes the absorption strength of each cell. The parameter ν can vary over many orders of magnitude between different cell types, ranging from bacteria and yeast to human tissue. The thickness ℓ decreases with increasing ν, increasing cell volume fraction ϕ, and decreasing ambient nutrient concentration ψ∞. The theoretical results are compared with numerical simulations and experiments. In the latter studies, colonies of budding yeast, Saccharomyces cerevisiae, are grown on glucose media and imaged under a confocal microscope. We measure the growth inside the colonies via a fluorescent protein reporter and compare the experimental and theoretical results for the thickness ℓ. PMID:23848711

  20. Concentration Dependences of the Surface Tension and Density of Solutions of Acetone-Ethanol-Water Systems at 293 K

    Science.gov (United States)

    Dadashev, R. Kh.; Dzhambulatov, R. S.; Mezhidov, V. Kh.; Elimkhanov, D. Z.

    2018-05-01

    Concentration dependences of the surface tension and density of solutions of three-component acetone-ethanol-water systems and the bounding binary systems at 273 K are studied. The molar volume, adsorption, and composition of surface layers are calculated. Experimental data and calculations show that three-component solutions are close to ideal ones. The surface tensions of these solutions are calculated using semi-empirical and theoretical equations. Theoretical equations qualitatively convey the concentration dependence of surface tension. A semi-empirical method based on the Köhler equation allows us to predict the concentration dependence of surface tension within the experimental error.

  1. Concentration-Discharge Responses to Storm Events in Coastal California Watersheds

    Science.gov (United States)

    Aguilera, Rosana; Melack, John M.

    2018-01-01

    Storm events in montane catchments are the main cause of mobilization of solutes and particulates into and within stream channels in coastal California. Nonlinear behavior of nutrients and suspended sediments during storms is evident in the hysteresis that arises in concentration-discharge (C-Q) relationships. We examined patterns in the C-Q hysteresis of nutrients (NO3-, NH4+, DON, and PO43-) and total suspended solids (TSS) during storms across 10 sites and water years 2002-2015 by quantifying the slope of the C-Q relationship and the rotational pattern of the hysteresis loop. We observed several hysteresis types in the ˜400 storms included in our study. Concentrations of constituents associated with sediment transport (PO43- and TSS) peaked during high flows. Conversely, nitrogen species had hysteretic responses such as dilution with clockwise rotation in urban sites and enrichment with anticlockwise rotation in undeveloped sites. The wide range of C-Q responses that occurred among sites and seasons reflected the variable hydrological and biogeochemical characteristics of catchments and storms. Responses for nitrate in nested catchments differed in slope and rotation of C-Q hysteresis. Upland undeveloped and lowland urban sites had anticlockwise rotation at the onset of the rainy season following a dry year, which implied a delay in the transport of this solute to the streams. Slopes by the middle of the rainy season showed that the urban site switched from dilution to enrichment, and then again to dilution with clockwise rotation at the end of the season, which implied high initial concentrations and proximal sources.

  2. Equilibrium and Dynamic Osmotic Behaviour of Aqueous Solutions with Varied Concentration at Constant and Variable Volume

    Science.gov (United States)

    Minkov, Ivan L.; Manev, Emil D.; Sazdanova, Svetla V.; Kolikov, Kiril H.

    2013-01-01

    Osmosis is essential for the living organisms. In biological systems the process usually occurs in confined volumes and may express specific features. The osmotic pressure in aqueous solutions was studied here experimentally as a function of solute concentration (0.05–0.5 M) in two different regimes: of constant and variable solution volume. Sucrose, a biologically active substance, was chosen as a reference solute for the complex tests. A custom made osmotic cell was used. A novel operative experimental approach, employing limited variation of the solution volume, was developed and applied for the purpose. The established equilibrium values of the osmotic pressure are in agreement with the theoretical expectations and do not exhibit any evident differences for both regimes. In contrast, the obtained kinetic dependences reveal striking divergence in the rates of the process at constant and varied solution volume for the respective solute concentrations. The rise of pressure is much faster at constant solution volume, while the solvent influx is many times greater in the regime of variable volume. The results obtained suggest a feasible mechanism for the way in which the living cells rapidly achieve osmotic equilibrium upon changes in the environment. PMID:24459448

  3. The effect of nutrient enrichment on the growth, nucleic acid concentrations, and elemental stoichiometry of coral reef macroalgae.

    Science.gov (United States)

    Reef, Ruth; Pandolfi, John M; Lovelock, Catherine E

    2012-08-01

    The growth rate hypothesis (GRH) links growth rates with organism elemental stoichiometry. Support for the GRH was found for many animal species, but less so for plants. This is the first study to test the GRH in macroalgae. Tropical coral reef macroalgae from three lineages, Caulerpa serrulata (Chlorophyta), Laurencia intricata (Rhodophyta), and Sargassum polyphyllum (Phaeophyceae) were grown enriched with nitrogen or phosphorous and under control conditions at Heron Island on the Great Barrier Reef, Australia. Growth rate, photosynthesis, nucleic acid composition, and elemental stoichiometry were measured. Nutrient enrichment had positive effects on photosynthetic rates and on investment in RNA. However, growth rate was not correlated with either photosynthetic rates or RNA content; thus, we did not find support for the GRH in tropical macroalgae. Macroalgae, especially L. intricata, accumulated P to very high levels (>0.6% of dry weight). The growth rate response to tissue P concentrations was unimodal. Above 0.21%, P accumulation had negative effects on growth. Nitrogen was not stored, but evidence of futile cycling was observed. The capacity to store large amounts of P is probably an adaptation to the low and patchy nutrient environment of the tropical oceans.

  4. Oxidative Pressure Leaching of Silver from Flotation Concentrates with Ammonium Thiocyanate Solution

    Science.gov (United States)

    Yang, Sheng-Hai; Yang, Jian-Guang; Liu, Wei; Chen, Geng-Tao; Tang, Mo-Tang; Qiu, Guan-Zhou

    2010-02-01

    The thermodynamics and technologies of the selective pressure leaching of silver from flotation concentrates were investigated in an ammonium thiocyanate medium. Thermodynamic analyses, which include silver solubility in NH4SCN solution and Eh-pH diagrams of the Me-MeS-NH4SCN-H2O system at 25 °C, were discussed. The effects of several factors, such as temperature, leaching time, oxidant, pH value, flotation concentrates concentration, surfactant concentration, and so on, on the extraction percentages of silver and zinc were investigated. The following optimal leaching conditions were obtained: NH4SCN concentration 1.5 M, lignin concentration 0.5 g/L, Fe3+ concentration 2 g/L, flotation concentrates addition 200 g/L, and oxygen pressure 1.2 MPa at 130 °C for 3 hours. Under these optimum conditions, the average extraction percentage of silver exceeded 94 pct, whereas the average extraction percentage of zinc was less than 3 pct. Only 7 pct of ammonium thiocyanate was consumed after 4 cycles, which indicated that ammonium thiocyanate hardly was oxidized under these oxidative pressure leaching conditions.

  5. Radiolysis of concentrated solutions. 1. Pulse and γ radiolysis studies of direct and indirect effects in LiCl solutions

    International Nuclear Information System (INIS)

    Pucheault, J.; Ferradini, C.; Julien, R.; Deysine, A.; Gilles, L.; Moreau, M.

    1979-01-01

    This study of the radiolysis of concentrated aqueous LiCl solutions enables the relative contributions of the direct and indirect effects to be evaluated as a function of Cl - concentration and also permits an evaluation of the role of Cl - in the early stages of water radiolysis. Radicalar and molecular yields G/sub Cl 2 - /, G/sub OH/, G//sub e//sub aq/ - / + G/sub H/, G/sub H 2 O 2 /, and G/sub H 2 / are determined for all concentrations employed, and the material balance is verified. The main conclusions concerning the apparent inefficacy of the direct effect and the importance of OH scavenging in spurs are discussed

  6. Trends in nutrient concentrations, loads, and yields in streams in the Sacramento, San Joaquin, and Santa Ana Basins, California, 1975-2004

    Science.gov (United States)

    Kratzer, Charles R.; Kent, Robert; Seleh, Dina K.; Knifong, Donna L.; Dileanis, Peter D.; Orlando, James L.

    2011-01-01

    A comprehensive database was assembled for the Sacramento, San Joaquin, and Santa Ana Basins in California on nutrient concentrations, flows, and point and nonpoint sources of nutrients for 1975-2004. Most of the data on nutrient concentrations (nitrate, ammonia, total nitrogen, orthophosphate, and total phosphorus) were from the U.S. Geological Survey's National Water Information System database (35.2 percent), the California Department of Water Resources (21.9 percent), the University of California at Davis (21.6 percent), and the U.S. Environmental Protection Agency's STOrage and RETrieval database (20.0 percent). Point-source discharges accounted for less than 1 percent of river flows in the Sacramento and San Joaquin Rivers, but accounted for close to 80 percent of the nonstorm flow in the Santa Ana River. Point sources accounted for 4 and 7 percent of the total nitrogen and total phosphorus loads, respectively, in the Sacramento River at Freeport for 1985-2004. Point sources accounted for 8 and 17 percent of the total nitrogen and total phosphorus loads, respectively, in the San Joaquin River near Vernalis for 1985-2004. The volume of wastewater discharged into the Santa Ana River increased almost three-fold over the study period. However, due to improvements in wastewater treatment, the total nitrogen load to the Santa Ana River from point sources in 2004 was approximately the same as in 1975 and the total phosphorus load in 2004 was less than in 1975. Nonpoint sources of nutrients estimated in this study included atmospheric deposition, fertilizer application, manure production, and tile drainage. The estimated dry deposition of nitrogen exceeded wet deposition in the Sacramento and San Joaquin Valleys and in the basin area of the Santa Ana Basin, with ratios of dry to wet deposition of 1.7, 2.8, and 9.8, respectively. Fertilizer application increased appreciably from 1987 to 2004 in all three California basins, although manure production increased in the

  7. Impact of managed moorland burning on peat nutrient and base cation status

    Science.gov (United States)

    Palmer, Sheila; Gilpin, Martin; Wearing, Catherine; Johnston, Kerrylyn; Holden, Joseph; Brown, Lee

    2013-04-01

    Controlled 'patch' burning of moorland vegetation has been used for decades in the UK to stimulate growth of heather (Calluna vulgaris) for game bird habitat and livestock grazing. Typically small patches (300-900 m2) are burned in rotations of 8-25 years. However, our understanding of the short-to-medium term environmental impacts of the practice on these sensitive upland areas has so far been limited by a lack of scientific data. In particular the effect of burning on concentrations of base cations and acid-base status of these highly organic soils has implications both for ecosystem nutrient status and for buffering of acidic waters. As part of the EMBER project peat chemistry data were collected in ten upland blanket peat catchments in the UK. Five catchments were subject to a history of prescribed rotational patch burning. The other five catchments acted as controls which were not subject to burning, nor confounded by other detrimental activities such as drainage or forestry. Soil solution chemistry was also monitored at two intensively studied sites (one regularly burned and one control). Fifty-centimetre soil cores, sectioned into 5-cm intervals, were collected from triplicate patches of four burn ages at each burned site, and from twelve locations at similar hillslope positions at each control site. At the two intensively monitored sites, soil solution chemistry was monitored at four depths in each patch. Across all sites, burned plots had significantly smaller cation exchange capacities, lower concentrations of exchangeable base cations and increased concentrations of exchangeable H+ and Al3+ in near-surface soil. C/N ratios were also lower in burned compared to unburned surface soils. There was no consistent trend between burn age and peat chemistry across all burned sites, possibly reflecting local controls on post-burn recovery rates or external influences on burn management decisions. At the intensively monitored site, plots burned less than two years

  8. [Influence of an infusion of 5- or 20% glucose solution on blood glucose and inorganic phosphate concentrations in dairy cows].

    Science.gov (United States)

    Aldaek, T A A; Failing, K; Wehrend, A; Klymiuk, M C

    2011-01-01

    The study was performed to evaluate the influence of an intravenous infusion of 5% and 20% dextrose solution on the plasma concentration of glucose and inorganic phosphate in healthy, dairy cows. Ten healthy, lactating, nonpregnant 3 to 6 year-old Holstein-Friesian cows were included in this investigation. The daily milk yield was 20.3±2.7 liters. Blood plasma concentrations of inorganic phosphate and glucose were determined before, during, immediately and 60 minutes after infusion of 0.9% physiological saline, 5% or 20% dextrose solution. A statistically significant influence of dextrose infusion on blood glucose concentration was observed. After 20% dextrose infusion (200 g dextrose) the blood glucose concentration increased by approximately 13.26 mmol/l. The administration of 5% dextrose solution (50 g dextrose) yielded an increase of blood glucose concentration by 3.31 mmol/l. There was no significant correlation between plasma inorganic phosphate concentrations and infusion of 0.9% saline, 5% or 20% dextrose solution. Intravenous administration of 1000 ml of 5% or 20% dextrose solution does not induce a lasting plasma phosphate reduction and is suitable for elevating the blood glucose concentration.

  9. Rape phosphatide concentrate in the technologies of surfactants production by the Actinobacteria

    Directory of Open Access Journals (Sweden)

    N. Koretska

    2015-05-01

    Full Text Available Introduction. Due to the fact that the production of microbial surfactants is limited by the low yield of end products and high cost of processes, the actual task is to optimize and reduce the cost of the technology of biosurfactants synthesis. One of the solutions of this problem is to use the industrial wastes, including rape phosphatide concentrate (PC. Materials and methods. Hexadecane and rape phosphatide concentrate (2% were used as a carbon source in a nutrient medium for the cultivation of bacteria. Lipids were extracted from a cell mass and supernatant by the mixture of chloroform-methanol 2:1. The qualitative analysis of metabolites was performed by a thin layer chromatography. Results and discussion. The peculiarities of synthesis of biosurfactants by strains G. rubripertincta UCM Aс-122 and R. erythropolis Au-1 during the growth on the nutrient media with rape phosphatide concentrate as a carbon source was studied. Quantity of biomass was 9.4 – 10.1 g/l, exopoly mers –8.9-9.5 g/l and the content of cellbound trehalose lipids was 1.37 – 2.26 g/l; whereas the content of exogenous trehalose lipids –metabolites of R. erythropolis Au-1 was 2.95 g/l. It was found that the addition of trehalose lipids (0.01 g/l to the nutrient medium caused the increase of biomass on 14.6 –17.0 % and cell-bound lipids on 13.9 –15.5 %. Conclusions. Rape phosphatide concentrate is economically viable carbon source in the technologies of surfactant production by Actinobacteria. Its use promotes an increasing of exogenous surfactants strain R. erythropolisAu-1 in 3-fold compared with cultivation on nutrient medium with hexadecane. Trehalose lipids show a stimulating effect on growth and synthesis of biosurfactants by strains of G. rubripertincta UCM Ac-122 and R. erythropolisAu-1.

  10. Upland and in-stream controls on baseflow nutrient dynamics in tile-drained agroecosystem watersheds

    Science.gov (United States)

    Controls on baseflow nutrient concentrations in agroecosystems are poorly characterized in comparison with storm events. However, in landscapes with low residence times (e.g., rivers and reservoirs), baseflow nutrient concentration dynamics during sensitive timeframes can drive deleterious environm...

  11. Similarity of nutrient uptake and root dimensions of Engelmann spruce and subalpine fir at two contrasting sites in Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Yanai, R; McFarlane, K; Lucash, M; Kulpa, S; Wood, D

    2009-10-09

    Nutrient uptake capacity is an important parameter in modeling nutrient uptake by plants. Researchers commonly assume that uptake capacity measured for a species can be used across sites. We tested this assumption by measuring the nutrient uptake capacity of intact roots of Engelmann spruce (Picea engelmanni Parry) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.) at Loch Vale Watershed and Fraser Experimental Forest in the Rocky Mountains of central Colorado. Roots still attached to the tree were exposed to one of three concentrations of nutrient solutions for time periods ranging from 1 to 96 hours, and solutions were analyzed for ammonium, nitrate, calcium, magnesium, and potassium. Surprisingly, the two species were indistinguishable in nutrient uptake within site for all nutrients (P > 0.25), but uptake rates differed by site. In general, nutrient uptake was higher at Fraser (P = 0.01, 0.15, 0.03, 0.18 for NH{sub 4}{sup +}, NO{sub 3}{sup -}, Ca{sup 2+}, and K{sup +}, respectively), which is west of the Continental Divide and has lower atmospheric deposition of N than Loch Vale. Mean uptake rates by site for ambient solution concentrations were 0.12 {micro}mol NH{sub 4}{sup +} g{sub fwt}{sup -1} h{sup -1}, 0.02 {micro}mol NO{sub 3}{sup -} g{sub fwt}{sup -1}, 0.21 {micro}mol Ca{sup 2+} g{sub fwt}{sup -1} h{sup -1}, and 0.01 {micro}mol Mg{sup 2+} g{sub fwt}{sup -1} h{sup -1} at Loch Vale, and 0.21 {micro}mol NH{sub 4}{sup +} f{sub fwt}{sup -1}h{sup -1}, 0.04 {micro}mol NO{sub 3}{sup -} g{sub fwt}{sup -1} h{sup -1}, 0.51 {micro}mol Ca{sup 2+}g{sub fwt}{sup -1}h{sup -1}, and 0.07 {micro}mol Mg{sup 2+} f{sub fwt}{sup -1}h{sup -1} at Fraser. The importance of site conditions in determining uptake capacity should not be overlooked when parameterizing nutrient uptake models. We also characterized the root morphology of these two species and compared them to other tree species we have measured at various sites in the northeastern USA. Engelman spruce and subalpine fir

  12. Recovery of nutrients from biogas digestate with biochar and clinoptilolite

    NARCIS (Netherlands)

    Kocaturk, N.P.

    2016-01-01

    The liquid fraction of digestate contains nutrients which makes it a valuable fertiliser in agricultural crop production systems. However, direct application of digestate may raise practical and environmental problems. Therefore, processes to concentrate nutrients have been proposed aiming not

  13. Efficacy of pectin solution for preventing gastro-esophageal reflux events in patients with percutaneous endoscopic gastrostomy.

    Science.gov (United States)

    Adachi, Kyoichi; Furuta, Kenji; Aimi, Masahito; Fukazawa, Kousuke; Shimura, Shino; Ohara, Shunji; Nakata, Shuji; Inoue, Yukiko; Ryuko, Kanji; Ishine, Junichi; Katoh, Kyoko; Hirata, Toshiaki; Ohhata, Shuzo; Katoh, Setsushi; Moriyama, Mika; Sumikawa, Masuko; Sanpei, Mari; Kinoshita, Yoshikazu

    2012-05-01

    The aim of this study was to determine the efficacy of pectin solution, which increases the viscosity of liquid nutrient, for prevention of gastro-esophageal reflux in comparison with half-solid nutrient. The subjects were 10 elderly patients undergoing percutaneous endoscopic gastrostomy feeding. Twenty-four-hour esophageal multichannel intraluminal impedance and pH testing was performed during intake of half-solid nutrient and a combination of pectin solution and liquid nutrient. During 4 h after delivery, there was no significant difference in the total number of gastro-esophageal reflux events between the feeding of the half-solid nutrient and the combination of pectin solution and liquid nutrient (5.7 ± 1.2 vs 5.3 ± 1.0/4 h). Acidic reflux after delivery of the half-solid nutrient was significantly more frequent than that after delivery of the combination of pectin solution and liquid nutrient (80.7% vs 60.4%, p = 0.018). The incidence of gastro-esophageal reflux reaching the upper portion of the esophagus tended to be higher during delivery of the half-solid nutrient than during delivery of the combination of pectin solution and liquid nutrient (47.4% vs 34.0%, p = 0.153). In conclusion, the usage of pectin solution combined with liquid nutrient is effective for preventing acidic gastro-esophageal reflux and gastro-esophageal reflux reaching the upper portion of the esophagus.

  14. Proposal for a method to estimate nutrient shock effects in bacteria

    Directory of Open Access Journals (Sweden)

    Azevedo Nuno F

    2012-08-01

    Full Text Available Abstract Background Plating methods are still the golden standard in microbiology; however, some studies have shown that these techniques can underestimate the microbial concentrations and diversity. A nutrient shock is one of the mechanisms proposed to explain this phenomenon. In this study, a tentative method to assess nutrient shock effects was tested. Findings To estimate the extent of nutrient shock effects, two strains isolated from tap water (Sphingomonas capsulata and Methylobacterium sp. and two culture collection strains (E. coli CECT 434 and Pseudomonas fluorescens ATCC 13525 were exposed both to low and high nutrient conditions for different times and then placed in low nutrient medium (R2A and rich nutrient medium (TSA. The average improvement (A.I. of recovery between R2A and TSA for the different times was calculated to more simply assess the difference obtained in culturability between each medium. As expected, A.I. was higher when cells were plated after the exposition to water than when they were recovered from high-nutrient medium showing the existence of a nutrient shock for the diverse bacteria used. S. capsulata was the species most affected by this phenomenon. Conclusions This work provides a method to consistently determine the extent of nutrient shock effects on different microorganisms and hence quantify the ability of each species to deal with sudden increases in substrate concentration.

  15. Effect of boron nutrition on American ginseng in field and in nutrient cultures

    Directory of Open Access Journals (Sweden)

    John T.A. Proctor

    2014-01-01

    Full Text Available Field and nutrient cultures of American ginseng (Panax quinquefolius L. were used to establish foliar symptoms related to boron (B concentration in leaves and soils, and to evaluate radish as a time-saving model system for B nutrition. Application of excess B, 8 kg/ha versus the recommended 1.5 kg/ha, to field plantings of 2-, 3-, and 4-yr-old American ginseng plants just prior to crop emergence caused, within 4 wk after crop emergence, leaf symptoms of chlorosis followed by necrosis starting at the tips and progressing along the margins. The B concentration in leaves of 2–4-yr-old plants receiving 1.5 kg/ha B was 30 μg/g dry mass compared to 460 μg/g dry mass where 8 kg/ha B was applied. Similarly, B concentration in soils receiving the lower B concentration was 1.8 μg/g dry mass and 2.2–2.8 μg/g dry mass where the higher B concentration was applied. Application of 8 kg/ha B reduced the dry yield of 3rd-yr roots by 20% from 2745 kg/ha to 2196 kg/ha and 4th-yr roots by 26% from 4130 kg/ha to 3071 kg/ha. Ginseng seedlings and radish were grown under greenhouse conditions in nutrient culture with four B concentrations ranging from 0 mg/L to 10 mg/L. At 5 mg/L and 10 mg/L ginseng and radish developed typical leaf B toxicity symptoms similar to those described above for field-grown plants. Increasing B in the nutrient solution from 0.5 mg/L to 10 mg/L decreased, in a linear fashion, the root and leaf dry mass of ginseng, but not radish. Given the many similarities of ginseng and radish to B utilization, radish might be used as a time-saving model system for the study of B, and other micronutrients, in the slow-growing perennial ginseng.

  16. Rhizosphere priming: a nutrient perspective

    Directory of Open Access Journals (Sweden)

    Feike Auke Dijkstra

    2013-07-01

    Full Text Available Rhizosphere priming is the change in decomposition of soil organic matter (SOM caused by root activity. Rhizosphere priming plays a crucial role in soil carbon (C dynamics and their response to global climate change. Rhizosphere priming may be affected by soil nutrient availability, but rhizosphere priming itself can also affect nutrient supply to plants. These interactive effects may be of particular relevance in understanding the sustained increase in plant growth and nutrient supply in response to a rise in atmospheric CO2 concentration. We examined how these interactions were affected by elevated CO2 in two similar semiarid grassland field studies. We found that an increase in rhizosphere priming enhanced the release of nitrogen (N through decomposition of a larger fraction of SOM in one study, but not in the other. We postulate that rhizosphere priming may enhance N supply to plants in systems that are N limited, but that rhizosphere priming may not occur in systems that are phosphorus (P limited. Under P limitation, rhizodeposition may be used for mobilisation of P, rather than for decomposition of SOM. Therefore, with increasing atmospheric CO2 concentrations, rhizosphere priming may play a larger role in affecting C sequestration in N poor than in P poor soils.

  17. Direct Analysis of Proteins from Solutions with High Salt Concentration Using Laser Electrospray Mass Spectrometry

    Science.gov (United States)

    Karki, Santosh; Shi, Fengjian; Archer, Jieutonne J.; Sistani, Habiballah; Levis, Robert J.

    2018-05-01

    The detection of lysozyme, or a mixture of lysozyme, cytochrome c, and myoglobin, from solutions with varying salt concentrations (0.1 to 250 mM NaCl) is compared using laser electrospray mass spectrometry (LEMS) and electrospray ionization-mass spectrometry (ESI-MS). Protonated protein peaks were observed up to a concentration of 250 mM NaCl in the case of LEMS. In the case of ESI-MS, a protein solution with salt concentration > 0.5 mM resulted in predominantly salt-adducted features, with suppression of the protonated protein ions. The constituents in the mixture of proteins were assignable up to 250 mM NaCl for LEMS and were not assignable above a NaCl concentration of 0.5 mM for ESI. The average sodium adducts () bound to the 7+ charge state of lysozyme for LEMS measurements from salt concentrations of 2.5, 25, 50, and 100 mM NaCl are 1.71, 5.23, 5.26, and 5.11, respectively. The conventional electrospray measurements for lysozyme solution containing salt concentrations of 0.1, 1, 2, and 5 mM NaCl resulted in of 2.65, 6.44, 7.57, and 8.48, respectively. LEMS displays an approximately two orders of magnitude higher salt tolerance in comparison with conventional ESI-MS. The non-equilibrium partitioning of proteins on the surface of the charged droplets is proposed as the mechanism for the high salt tolerance phenomena observed in the LEMS measurements. [Figure not available: see fulltext.

  18. Concentration of Rutin Model Solutions from Their Mixtures with Glucose Using Ultrafiltration

    Directory of Open Access Journals (Sweden)

    Zaid S. Saleh

    2010-02-01

    Full Text Available Separation of polyphenolic phytochemical compounds from their mixtures with sugars is necessary to produce an added-value sugar-reduced extract with high biological activity from fruit juice processing industry waste streams. The separation characteristics of a binary mixture of rutin and glucose using a Pellicon-2 regenerated cellulose ultrafiltration membrane with an area of 0.1 m2 having nominal MWCO of 1,000 Da were investigated, to demonstrate the separation of phenolic compounds from sugars. The effects of the operating variables–transmembrane pressure, feed solution temperature and pH, initial feed concentration and feed flow rate–on the permeate flux and enrichment of rutin, were determined. The permeate flux increased with the increase in transmembrane pressure up to a certain limit and after that the flux remained more or less constant. The optimum transmembrane pressure was within 4–5 bar. The flux increased with the increase in feed solution temperature because of reduced feed viscosity, and better solubility. The concentration of rutin was optimum at lower temperature (30ºC, with an enrichment factor of 1.3. The effect of pH on permeate flux was less obvious. Lowering the feed solution pH increased the retention of rutin and the optimum separation was obtained within pH 3–4. The permeate flux decreased with the increase in feed concentration of rutin (concentration range 0.1–0.5 g/L. The enrichment of rutin was significant in the glucose concentration range 0.35–0.5 g/L. The feed flow rate had a significant effect on the flux and separation characteristics. Higher cross-flow through the membrane reduced the fouling by providing a shear force to sweep away deposited materials from the membrane surface. At high feed flow rate, more rutin was retained by the membrane with less sugar permeating through. The optimum feed flow rate was 1.5 L/min. For the separation of rutin (in the retentate and glucose (in the permeate, the

  19. The quality of our Nation's waters-Nutrients in the Nation's streams and groundwater, 1992-2004

    Science.gov (United States)

    Dubrovsky, N.M.; Burow, K.R.; Clark, G.M.; Gronberg, J.M.; Hamilton, P.A.; Hitt, K.J.; Mueller, D.K.; Munn, M.D.; Nolan, B.T.; Puckett, L.J.; Rupert, M.G.; Short, T.M.; Spahr, N.E.; Sprague, L.A.; Wilber, W.G.

    2010-01-01

    National Findings and Their Implications Although the use of artificial fertilizer has supported increasing food production to meet the needs of a growing population, increases in nutrient loadings from agricultural and, to a lesser extent, urban sources have resulted in nutrient concentrations in many streams and parts of aquifers that exceed standards for protection of human health and (or) aquatic life, often by large margins. Do NAWQA findings substantiate national concerns for aquatic and human health? National Water-Quality Assessment (NAWQA) findings indicate that nutrient concentrations in streams and groundwater in basins with significant agricultural or urban development are substantially greater than naturally occurring or ?background? levels. For example, median concentrations of total nitrogen and phosphorus in agricultural streams are about 6 times greater than background levels. Findings also indicate that concentrations in streams routinely were 2 to 10 times greater than regional nutrient criteria recommended by the U.S. Environmental Protection Agency (USEPA) to protect aquatic life. Such large differences in magnitude suggest that significant reductions in sources of nutrients, as well as greater use of land management strategies to reduce the transport of nutrients to streams, are needed to meet recommended criteria for streams draining areas with significant agricultural and urban development. Nitrate concentrations above the Federal drinking-water standard-or Maximum Contaminant Level (MCL)-of 10 milligrams per liter (mg/L, as nit-ogen) are relatively uncommon in samples from streams used for drinking water or from relatively deep aquifers; the MCL is exceeded, however, in more than 20 percent of shallow (less than 100 feet below the water table) domestic wells in agricultural areas. This finding raises concerns for human health in rural agricultural areas where shallow groundwater is used for domestic supply and may warn of future

  20. Morphological and Structural Analysis of Nano-hydroxyapatite (n-hap) Coatings Electrodeposited on Titanium Substrate : Effect of Deposition Solution Concentration

    International Nuclear Information System (INIS)

    Nik Norziehana Che Isa; Norjanah Yury; Yusairie Mohd

    2011-01-01

    Various concentration of deposition solutions containing CaCl 2 and NH 4 H 2 PO 4 (with Ca/P ratio equal to 1.67) were used to study the effect of deposition solution concentration on the surface morphology and structure of Hydroxyapatite (HAp) coatings. Each HAp coating was deposited onto Ti substrate by applying a constant potential of 1.5 V (vs Ag/ AgCl) at 80 degree Celsius. The formation of HAp coatings was confirmed by FTIR and XRD analyses. Various morphologies consisting of HAp nanoparticles were produced from different deposition solutions as observed by SEM. The concentration of deposition solution has significantly affected the morphology of n-HAp coatings. (author)

  1. Treatment of Source-Separated Blackwater: A Decentralized Strategy for Nutrient Recovery towards a Circular Economy

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    Melesse Eshetu Moges

    2018-04-01

    Full Text Available Using a filter medium for organic matter removal and nutrient recovery from blackwater treatment is a novel concept and has not been investigated sufficiently to date. This paper demonstrates a combined blackwater treatment and nutrient-recovery strategy and establishes mechanisms for a more dependable source of plant nutrients aiming at a circular economy. Source-separated blackwater from a student dormitory was used as feedstock for a sludge blanket anaerobic-baffled reactor. The effluent from the reactor, with 710 mg L−1 NH4–N and 63 mg L−1 PO4–P, was treated in a sequence of upflow and downflow filtration columns using granular activated carbon, Cocos char and polonite as filter media at a flow rate of 600 L m−2 day−1 and organic loading rate of 430 g chemical oxygen demand (COD m−2 day−1. Filtration treatment of the anaerobic effluent with carbon adsorbents removed 80% of the residual organic matter, more than 90% of suspended solids, and turbidity while releasing more than 76% NH4–N and 85% of PO4–P in the liquid phase. The treatment train also removed total coliform bacteria and E. coli in the effluent, achieving concentrations below detection limit after the integration of ultraviolet (UV light. These integrated technological pathways ensure simultaneous nutrient recovery as a nutrient solution, pathogen inactivation, and reduction of active organic substances. The treated nutrient-rich water can be applied as a source of value creation for various end-use options.

  2. Gastric volume rather than nutrient content inhibits food intake.

    Science.gov (United States)

    Phillips, R J; Powley, T L

    1996-09-01

    To evaluate the separate contributions of distension and nutrient stimulation of the stomach to the inhibition of short-term food intake and, particularly, to reassess previous analyses based on the inflatable gastrointestinal cuff, four experiments were performed. Rats equipped with pyloric cuffs and indwelling gastric catheters consumed a liquid diet ad libitum. Their consumption during short-term (30 min) feeding bout was measured after gastric infusions on cuff-open and cuff-closed trials. Animals taking meals (approximately 5 ml) with cuffs closed immediately after receiving intragastric infusions of 2.5, 5, 7.5, or 10 ml of normal saline exhibited both suppression at the smallest infusion and a dose-dependent reduction across the other volumes (experiment 1). Additionally, when the test diet concentration was varied, animals with their cuffs closed consumed a constant volume, not a constant number of calories (experiment 2). Furthermore, cuff-closed animals exhibited no more suppression to 5-ml intragastric infusions of nutrients (including, on different trials, 50 and 100% Isocal diet; 10, 20, and 40% glucose; and 40% sucrose and 40% fructose) than to the same volume of saline (experiments 3 and 4). In contrast, on cuff-open trials in which gastric contents could empty into the duodenum, these same nutrient loads were more effective (except fructose) than saline in producing suppression of food intake. In summary, although both limited gastric distension with the pylorus occluded and intestinal nutrient stimulation with the cuff open effectively reduced intake, cuff-closed gastric loads of mixed macronutrients or carbohydrate solutions of 2-8 kcal, pH from 5.8 to 6.7, and osmolarities between 117 and 2,294 mosM/kg produced only the distension-based suppression generated by the same volume of saline.

  3. Effect of molybdenum on yield and nutrient content of the strawberry

    International Nuclear Information System (INIS)

    Bender, R.J.; Barros, I.B.I. de

    1984-01-01

    The cultivation of strawberries (Fragaria x ananassa Duch.) cv. Campinas in nutrient solution using five fields levels of molybdenum (MO), 0.010 ppm, 0.010 ppm, 0.10 ppm, 1.0 ppm and control (Without applying molybdenum). The experiment was carried out in greenhouse and phytothron to evaluate the changes in the mineral status of the leaves and the quality of the berries. The concentration of Mo in the leaves, at the beginning of fruiting stage, varied from 0.5 ppm to 64 ppm. The total N in the levels was affected significantly by Mo. Average weight of the berries were affected by treatments and presented a quadratic regression response. (M.A.C.) [pt

  4. δ15N of seagrass leaves for monitoring anthropogenic nutrient increases in coral reef ecosystems

    International Nuclear Information System (INIS)

    Yamamuro, M.; Kayanne, H.; Yamano, H.

    2003-01-01

    In a coral reef environment, a slight increase in dissolved inorganic nitrogen (DIN;≥1.0 μM) can alter the ecosystem via macroalgal blooms. We collected seagrass leaves from the tropical and subtropical Pacific Ocean in five countries and examined the interactions between nutrient concentrations (C, N, P), molar ratios of nutrients, and δ 15 N to find a possible indicator of the DIN conditions. Within most sites, the concentrations of nutrients and their molar ratios showed large variations owing to species-specific values. On the other hand, almost identical δ 15 N values were found in seagrass leaves of several species at each site. The correlations between δ 15 N and nutrient concentrations and between δ 15 N and molar ratios of nutrients suggested that nutrient availability did not affect the δ 15 N value of seagrass leaves by altering the physiological condition of the plants. Increases in δ 15 N of seagrass leaves mostly matched increases in DIN concentrations in the bottom water. We suggest that δ 15 N in seagrass leaves can be a good tool to monitor time-integrated decrease/increase of DIN concentrations at a site, both in the water column and the interstitial water

  5. Physiological responses of sweet potato (Ipomoea batatas L. plants due to different copper concentrations

    Directory of Open Access Journals (Sweden)

    Cristina Copstein Cuchiara

    2015-12-01

    Full Text Available At low concentrations, Cu is considered as an essential micronutrient for plants and as a constituent and activator of several enzymes. However, when in excess, Cu can negatively affect plant growth and metabolism. Therefore, the aim of this study was to evaluate physiological responses of sweet potato plants at different Cu concentrations by measuring morphological parameters, antioxidant metabolism, stomatal characteristics, and mineral profile. For this purpose, sweet potato plants were grown hydroponically in complete nutrient solution for six days. Then, the plants were transferred to solutions containing different Cu concentrations, 0.041 (control, 0.082, and 0.164 mM, and maintained for nine days. The main effect of increased Cu concentration was observed in the roots. The sweet potato plants grown in 0.082 mM Cu solution showed increased activity of antioxidant enzymes and no changes in growth parameters. However, at a concentration of 0.164 mM, Cu was transported from the roots to the shoots. This concentration altered morpho-anatomical characteristics and activated the antioxidant system because of the stress generated by excess Cu. On the basis of the results, it can be concluded that the sweet potato plants were able to tolerate Cu toxicity until 0.082 mM.

  6. Photoluminescence Spectroscopy of Rhodamine 800 Aqueous Solution and Dye-Doped Polymer Thin-Film: Concentration and Solvent Effects

    Science.gov (United States)

    Le, Khai Q.; Dang, Ngo Hai

    2018-05-01

    This paper investigates solvent and concentration effects on photoluminescence (PL) or fluorescence properties of Rhodamine 800 (Rho800) dyes formed in aqueous solution and polymer thin-film. Various commonly used organic solvents including ethanol, methanol and cyclopentanol were studied at a constant dye concentration. There were small changes in the PL spectra for the different solvents in terms of PL intensity and peak wavelength. The highest PL intensity was observed for cyclopentanol and the lowest for ethanol. The longest peak wavelength was found in cyclopentanol (716 nm) and the shortest in methanol (708 nm). Dissolving the dye powder in the methanol solvent and varying the dye concentration in aqueous solution from the high concentrated solution to highly dilute states, the wavelength tunability was observed between about 700 nm in the dilute state and 730 nm at high concentration. Such a large shift may be attributed to the formation of dye aggregates. Rho800 dye-doped polyvinyl alcohol (PVA) polymer thin-film was further investigated. The PL intensity of the dye in the form of thin-film is lower than that of the aqueous solution form whereas the peak wavelength is redshifted due to the presence of PVA. This paper, to our best knowledge, reports the first study of spectroscopic properties of Rho800 dyes in various forms and provides useful guidelines for production of controllable organic luminescence sources.

  7. Diagnosis of nutrient imbalances with vector analysis in agroforestry systems.

    Science.gov (United States)

    Isaac, Marney E; Kimaro, Anthony A

    2011-01-01

    Agricultural intensification has had unintended environmental consequences, including increased nutrient leaching and surface runoff and other agrarian-derived pollutants. Improved diagnosis of on-farm nutrient dynamics will have the advantage of increasing yields and will diminish financial and environmental costs. To achieve this, a management support system that allows for site-specific rapid evaluation of nutrient production imbalances and subsequent management prescriptions is needed for agroecological design. Vector diagnosis, a bivariate model to depict changes in yield and nutritional response simultaneously in a single graph, facilitates identification of nutritional status such as growth dilution, deficiency, sufficiency, luxury uptake, and toxicity. Quantitative data from cocoa agroforestry systems and pigeonpea intercropping trials in Ghana and Tanzania, respectively, were re-evaluated with vector analysis. Relative to monoculture, biomass increase in cocoa ( L.) under shade (35-80%) was accompanied by a 17 to 25% decline in P concentration, the most limiting nutrient on this site. Similarly, increasing biomass with declining P concentrations was noted for pigeonpea [ (L). Millsp.] in response to soil moisture availability under intercropping. Although vector analysis depicted nutrient responses, the current vector model does not consider non-nutrient resource effects on growth, such as ameliorated light and soil moisture, which were particularly active in these systems. We revisit and develop vector analysis into a framework for diagnosing nutrient and non-nutrient interactions in agroforestry systems. Such a diagnostic technique advances management decision-making by increasing nutrient precision and reducing environmental issues associated with agrarian-derived soil contamination. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

  8. Nutrient dynamics across a dissolved organic carbon and burn gradient in central Siberia

    Science.gov (United States)

    Rodriguez-Cardona, B.; Coble, A. A.; Prokishkin, A. S.; Kolosov, R.; Spencer, R. G.; Wymore, A.; McDowell, W. H.

    2016-12-01

    In stream ecosystems, dissolved organic carbon (DOC) and nitrogen (N) processing are tightly linked. In temperate streams, greater DOC concentrations and higher DOC:NO3- ratios promote the greatest nitrate (NO3-) uptake. However, less is known about this relationship in other biomes including the arctic which is undergoing changes due to climate change contributing to thawing of permafrost and alterations in biogeochemical cycles in soils and streams. Headwater streams draining into the N. Tunguska River in the central Siberian plateau are affected by forest fires but little is known about the aquatic biogeochemical implications in both a thawing and burning landscape. There are clear patterns between carbon concentration and fire history where generally DOC concentration in streams decrease after fires and older burn sites have shown greater DOC concentrations and more bioavailable DOC that could promote greater heterotrophic uptake of NO3-. However, the relationship between nutrient dynamics, organic matter composition, and fire history in streams is not very clear. In order to assess the influence of organic matter composition and DOC concentration on nutrient uptake in arctic streams, we conducted a series of short-term nutrient addition experiments following the tracer addition for spiraling curve characterization (TASCC) method, consisting of NO3- and NH4++PO43- additions, across 4 streams that comprise a fire gradient that spans 3- >100 years since the last burn with DOC concentrations ranging between 12-23 mg C/L. We hypothesized that nutrient uptake would be greatest in older burn sites due to greater DOC concentrations and availability. We will specifically examine how nutrient uptake relates to DOC concentration and OM composition (analyzed via FTICR-MS) across the burn gradient. Across the four sites DOC concentration and DOC:NO3- ratios decreased from old burn sites to recently burned sites. Results presented here can elucidate on the potential impacts

  9. Synthesis of Copper-Chelates Derived from Amino Acids and Evaluation of Their Efficacy as Copper Source and Growth Stimulator for Lactuca sativa in Nutrient Solution Culture.

    Science.gov (United States)

    Kaewchangwat, Narongpol; Dueansawang, Sattawat; Tumcharern, Gamolwan; Suttisintong, Khomson

    2017-11-15

    Five tetradentate ligands were synthesized from l-amino acids and utilized for the synthesis of Cu(II)-chelates 1-5. The efficacy of Cu(II)-chelates as copper (Cu) source and growth stimulator in hydroponic cultivation was evaluated with Lactuca sativa. Their stability test was performed at pH 4-10. The results suggested that Cu(II)-chelate 3 is the most pH tolerant complex. Levels of Cu, Zn, and Fe accumulated in plants supplied with Cu(II)-chelates were compared with those supplied with CuSO 4 at the same Cu concentration of 8.0 μM. The results showed that Cu(II)-chelate 3 significantly enhanced Cu, Zn, and Fe content in shoot by 35, 15, and 48%, respectively. Application of Cu(II)-chelate 3 also improved plant dry matter yield by 54%. According to the results, Cu(II)-chelate 3 demonstrated the highest stimulating effect on plant growth and plant mineral accumulation so that it can be used as an alternative to CuSO 4 for supplying Cu in nutrient solutions and enhancing the plant growth.

  10. Alocação de biomassa e nutrientes em Heteranthera reniformis sob o efeito de N, P e K Allocation of biomass and nutrients in Heteranthera reniformis under the effect of N, P and K

    Directory of Open Access Journals (Sweden)

    V.D. Domingos

    2005-03-01

    Full Text Available Este trabalho objetivou estudar a distribuição de biomassa e nutrientes entre os componentes vegetativos de Heteranthera reniformis sob o efeito de diferentes concentrações de N, P e K. As plantas foram cultivadas em vasos plásticos preenchidos com pedra rolada, em soluções nutritivas a 80% da concentração original de Sarruge, sendo esta a solução-base. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro níveis (0, 25, 50 e 75% da solução-base avaliados individualmente em N, P e K, além da testemunha (100% da solução-base, com quatro repetições no período de 35 dias. As maiores áreas foliares ocorreram em soluções com 75% de P e 50% de N e K. A solução com 50% de N proporcionou a maior biomassa seca de plantas. A contribuição do caule na alocação de recursos apresentou resultados que variaram entre 55,5 e 74,5% em relação à matéria seca total referente ao nível 0 e 75% de N; a contribuição de raízes reduziu com o aumento da concentração de N, bem como de P e K. As maiores contribuições de raízes ocorreram nas ausências de N (26,8% e P (19,2%, os quais foram maiores em relação aos seus respectivos níveis mais concentrados. Os teores de N, P e K corresponderam a uma ordem crescente em folha, caule e raízes, em que os maiores teores foram obtidos nos níveis de 50 a 125 mg L-1 de N, 5 a 15 mg L-1 de P e 100 a 150 mg L- 1 de K.This research aimed to study the biomass and nutrient distribution among the vegetative components of Heteranthera reniformis under the effect of different concentrations of N, P and K. The plants were cultivated in plastic pots filled with rolled stone, in nutrient solutions with 80% of the original concentration of Sarruge as the base solution. The experimental design was completely randomized, at 5 levels (0, 25, 50, 75% of the base solution evaluated individually in N, P and K, besides the control (100% of the base solution, with 4 replicates in

  11. Seasonal dynamics of nitrate and ammonium ion concentrations in soil solutions collected using MacroRhizon suction cups.

    Science.gov (United States)

    Kabala, Cezary; Karczewska, Anna; Gałka, Bernard; Cuske, Mateusz; Sowiński, Józef

    2017-07-01

    The aims of the study were to analyse the concentration of nitrate and ammonium ions in soil solutions obtained using MacroRhizon miniaturized composite suction cups under field conditions and to determine potential nitrogen leaching from soil fertilized with three types of fertilizers (standard urea, slow-release urea, and ammonium nitrate) at the doses of 90 and 180 kg ha -1 , applied once or divided into two rates. During a 3-year growing experiment with sugar sorghum, the concentration of nitrate and ammonium ions in soil solutions was the highest with standard urea fertilization and the lowest in variants fertilized with slow-release urea for most of the months of the growing season. Higher concentrations of both nitrogen forms were noted at the fertilizer dose of 180 kg ha -1 . One-time fertilization, at both doses, resulted in higher nitrate concentrations in June and July, while dividing the dose into two rates resulted in higher nitrate concentrations between August and November. The highest potential for nitrate leaching during the growing season was in July. The tests confirmed that the miniaturized suction cups MacroRhizon are highly useful for routine monitoring the concentration of nitrate and ammonium ions in soil solutions under field conditions.

  12. Stressor-Response Models Relating Nutrient Enrichment to Algal Communities in Pacific Northwest Streams and Rivers

    Science.gov (United States)

    Sobota, D. J.; Hubler, S.; Paul, M. J.; Labiosa, R.

    2015-12-01

    Excessive algal growth in streams and rivers from nutrient enrichment can cause costly human health and environmental problems. As part of the US Environmental Protection Agency's Nutrient Scientific Technical Exchange Partnership and Support (N-STEPS) program, we have been developing stressor-response (S-R) models relating nutrients to attached algal (periphyton) communities to help prioritize monitoring for water quality impairments in Oregon (Pacific Northwest, USA) streams and rivers. Existing data from the state and neighboring states were compiled and standardized from the Oregon Department of Environmental Quality, US Environmental Protection Agency, and the US Geological Survey. To develop S-R models, algal community and biomass metrics were compared with nitrogen (N) and phosphorus (P) concentration data, including total, dissolved, and inorganic forms of these nutrients. In total, 928 paired algal-nutrient samples were compiled from the 8 Level-III Ecoregions occurring in Oregon. Relationships between algal biomass metrics and nutrient concentrations were weak, with only ash-free dry mass and standing stock of chlorophyll a showing slight positive relationships across gradients of total N and soluble reactive P concentrations, respectively. In contrast, metrics describing algal community composition, including percent diatoms and abundance of nutrient-sensitive species, showed very strong nonlinear relationships with total N or P concentrations. This suggests that data describing algal community composition can help identify specific nutrient stressors across environmentally-diverse streams and rivers in the Pacific Northwest. Future analyses will examine if nutrient-algal S-R models vary across different hydrological, physiographical, and ecological settings in the region.

  13. Trees and Streets as Drivers of Urban Stormwater Nutrient Pollution.

    Science.gov (United States)

    Janke, Benjamin D; Finlay, Jacques C; Hobbie, Sarah E

    2017-09-05

    Expansion of tree cover is a major management goal in cities because of the substantial benefits provided to people, and potentially to water quality through reduction of stormwater volume by interception. However, few studies have addressed the full range of potential impacts of trees on urban runoff, which includes deposition of nutrient-rich leaf litter onto streets connected to storm drains. We analyzed the influence of trees on stormwater nitrogen and phosphorus export across 19 urban watersheds in Minneapolis-St. Paul, MN, U.S.A., and at the scale of individual streets within one residential watershed. Stormwater nutrient concentrations were highly variable across watersheds and strongly related to tree canopy over streets, especially for phosphorus. Stormwater nutrient loads were primarily related to road density, the dominant control over runoff volume. Street canopy exerted opposing effects on loading, where elevated nutrient concentrations from trees near roads outweighed the weak influence of trees on runoff reduction. These results demonstrate that vegetation near streets contributes substantially to stormwater nutrient pollution, and therefore to eutrophication of urban surface waters. Urban landscape design and management that account for trees as nutrient pollution sources could improve water quality outcomes, while allowing cities to enjoy the myriad benefits of urban forests.

  14. [Analyze nanofiltration separation rule of chlorogenic acid from low concentration ethanol by Donnan effect and solution-diffusion effect].

    Science.gov (United States)

    Li, Cun-Yu; Liu, Li-Cheng; Jin, Li-Yang; Li, Hong-Yang; Peng, Guo-Ping

    2017-07-01

    To separate chlorogenic acid from low concentration ethanol and explore the influence of Donnan effect and solution-diffusion effect on the nanofiltration separation rule. The experiment showed that solution pH and ethanol volume percent had influences on the separation of chlorogenic acid. Within the pH values from 3 to 7 for chlorogenic acid in 30% ethanol, the rejection rate of chlorogenic acid was changed by 70.27%. Through the response surface method for quadratic regression model, an interaction had been found in molecule weight cut-off, pH and ethanol volume percent. In fixed nanofiltration apparatus, the existence states of chlorogenic acid determinedits separation rules. With the increase of ethanol concentration, the free form chlorogenic acid was easily adsorbed, dissolved on membrane surface and then caused high transmittance due to the solution-diffusion effect. However, at the same time, due to the double effects of Donnan effect and solution-diffusion effect, the ionic state of chlorogenic acid was hard to be adsorbed in membrane surface and thus caused high rejection rate. The combination of Box-Behnken design and response surface analysis can well optimize the concentrate process by nanofiltration, and the results showed that nanofiltration had several big advantages over the traditional vacuum concentrate technology, meanwhile, and solved the problems of low efficiency and serious component lossesin the Chinese medicines separation process for low concentration organic solvent-water solution. Copyright© by the Chinese Pharmaceutical Association.

  15. The role of aquatic fungi in transformations of organic matter mediated by nutrients

    Science.gov (United States)

    Cynthia J. Tant; Amy D. Rosemond; Andrew S. Mehring; Kevin A. Kuehn; John M. Davis

    2015-01-01

    1. We assessed the key role of aquatic fungi in modifying coarse particulate organic matter (CPOM) by affecting its breakdown rate, nutrient concentration and conversion to fine particulate organic matter (FPOM). Overall, we hypothesised that fungal-mediated conditioning and breakdown of CPOM would be accelerated when nutrient concentrations are increased and tested...

  16. Nutrient Budgets Calculated in Floodwaters Using a Whole-Ecosystem Experimental Manipulation

    Science.gov (United States)

    Talbot, C. J.; Paterson, M. J.; Xenopoulos, M. A.

    2017-12-01

    Flooding provides pathways for nutrients to move into surface waters and alter nutrient concentrations, therefore influencing downstream ecosystems and increasing events of eutrophication. Nutrient enrichment will likely affect water quality, primary production, and overall ecosystem function. Quantifying nutrient movement post-flood will help evaluate the risks or advantages that flooding will have on ecosystem processes. Here we constructed nutrient budgets using data collected as part of the Flooded Upland Dynamics Experiment (FLUDEX) at the Experimental Lakes Area (ELA) in northwestern Ontario. Three experimental reservoirs with varying amounts of stored carbon were created by flooding forested land from May through September annually from 1999 to 2003. Organic matter became a significant source of nutrients under flooded conditions and elevated reservoir total nitrogen (TN) and total phosphorus (TP) concentrations within one week of flooding. The highest TN (2.6 mg L-1) and TP (579 µg L-1) concentrations throughout the entire flooding experiment occurred in the medium carbon reservoir within the first two weeks of flooding in 1999. TN and TP fluxes were positive in all years of flooding. TP fluxes decreased after each flooding season therefore, TP production may be less problematic in floodplains subject to frequent repeated flooding. However, TN fluxes remained large even after repeated flooding. Therefore, flooding, whether naturally occurring or from anthropogenic flow alteration, may be responsible for producing significant amounts of nitrogen and phosphorus in aquatic ecosystems.

  17. Differential Concentrations of some Nutrient Element in Forage of Corn (Zea mays L. as Affected by Organic Fertilizers and Soil Compaction

    Directory of Open Access Journals (Sweden)

    N. Najafi

    2016-01-01

    Full Text Available Soil compaction is one of the most important limiting factor for normal crop growth, because it reduces absorption by the plant. Application of organic fertilizers in agricultural soils can reduce the detrimental effects of soil compaction on plant growth and also supply some nutrients to plant. Thus, a factorial experiment was carried out in a randomized complete block design with three replications and 14 treatments to evaluate the effects of organic fertilizers in mitigating soil compaction. The first factor in this study was the source and amount of organic fertilizer at seven levels (control, farmyard manure, sewage sludge compost and municipal solid waste compost and each of organic fertilizers at two levels of 15 and 30 g/kg of soil. The second factor was soil compaction at two levels (bulk density of 1.2 and 1.7 g/cm3. To perform this experiment, 10 kg of dry soil was poured into special PVC pots and then seeds of single cross 704 corn were planted. At the end of the growth period, the corn shoot was harvested and concentrations of phosphorus (P, potassium (K, sodium (Na, iron (Fe, zinc (Zn, manganese (Mn, cadmium (Cd and lead (Pb were determined by dry ashing method. The results showed that concentrations of Cd and Pb in the shoot, related to the different treatments, were negligible. Concentrations of P, K, Fe, Mn and Zn in the corn shoot were increased significantly by application of farmyard manure, sewage sludge compost and municipal solid waste compost at both levels of soil compaction. However, Na concentration of shoot did not change significantly. Soil compaction significantly reduced P, Fe, Mn and Zn concentrations of corn shoot, but it affected concentrations of Na and K significantly. Application of organic fertilizers and increasing their levels reduced the negative effects of soil compaction on nutrients uptake by corn plant. This study showed that to improve forage corn nutrition, application of 15 or 30 g of farmyard

  18. Sweet pepper production in substrate in response to salinity, nutrient solution management and training system Produção de pimentão cultivado em substrato em resposta à salinidade, manejo da solução nutritiva e sistema de condução

    Directory of Open Access Journals (Sweden)

    José S Rubio

    2011-09-01

    Full Text Available The objective of the present study was to evaluate the marketable fruit yield of sweet pepper plants (Capsicum annuum cv. Orlando in function of the management of nutrient solution with training system. Plants were grown on coconut coir dust under greenhouse conditions in the southeast of Spain. A randomized block design in split-split plot with four blocks was used to test the effect of the nutrient solution strength (full or half-strength Hoagland nutrient solution, training system (two and three stems per plant and water salinity (saline and non-saline on total and marketable yield, fruit quality, and fruit mineral concentration. Salt treatment decreased fruit yield by decreasing the fruit fresh weight but not the number of fruits per plant. Under saline and non-saline conditions, the higher yield of fruits was obtained in plants watered with half-strength Hoagland solution, and grown with three stems per plant. Blossom end rot incidence increased under saline conditions or using full-strength Hoagland solution, but decreased with the combination of half-strength Hoagland solution and three-stem training system. Salt treatment also decreased fruit quality in all the treatments due to a decrease in PO2-, SO4(2-, Fe2+;3+, Cu1+;2+ and Mn2+ concentrations, and fruit shape index. Likewise, plants exposed to salinity and watered with half-strength Hoagland solution and trained with three stems showed a reduction in juice glucose and fructose concentration. Based on these results, an increase of the marketable fruit yield could be obtained under non or moderate saline conditions with the implementation of suitable culture practices.Este experimento teve como objetivo avaliar a produção comercial de pimentão doce (Capsicum annuum cv. Orlando em função do manejo da solução nutritiva, da salinidade e do sistema de condução. As plantas de pimentão doce foram cultivadas em substrato de fibra de coco em casa de vegetação no sudeste da Espanha

  19. Effect of Plant Growth Promoting Rhizobacteria on the Concentration and Uptake of Macro Nutrients by Corn in a Cd-contaminated Calcareous Soil under Drought Stress

    Directory of Open Access Journals (Sweden)

    shahrzad karami

    2017-02-01

    Full Text Available Introduction: Heavy metals such as cadmium (Cd are found naturally in soils, but their amount can be changed by human activities. The study of the uptake and accumulation of heavy metals by plants is done in order to prevent their threats on human and animal’s health.Cadmium is a toxic element for living organisms. Cadmium competes with many of nutrients to be absorbed by the plant and interferes with their biological roles. Water stress affects the cell structure and the food is diverted from its normal metabolic pathway. It also reduces the availability and uptake of nutrients by the plant. One reason for the reduction of plant growth under drought stress is the accumulation of ethylene in plants. There are ways to mitigate the negative effects of drought stress that one of which is the use of Plant Growth Promoting Rhizobacteria(PGPRs to increasing the availability of nutrients. Soil beneficial bacteria play an important role in the biological cycles and have been used to increase plant health and soil fertility over the past few decades.The aim of this study was to investigate theeffect of PGPRson the concentration and uptake of macro nutrients by corn in a Cd-contaminated calcareous soil under drought stress. Materials and Methods: A greenhouse factorial experiment was conducted in a completely randomized design with three replications. The treatments were two levels of bacteria (with and without bacteria, four levels of Cd (5, 10, 20, and 40 mg kg-1, and three levels of drought stress (without stress, 80, and 65% of field capacity. The pots were filled with 3 kg of treated soil. Cd was treated as its sulfate salt in amounts of 5, 10, 20, and 40 mg kg-1. The soil was mixed uniformly with 150 mg N kg-1 as urea, 20 mg P kg-1 as Ca (H2PO42, 5 mg Fe kg-1 as Fe-EDDHA and 10, 10 and 2.5 mg Zn, Mn and Cu kg-1, respectively as their sulfate salt in order to meet plant needs for these nutrients. Six seeds of Zea mays (var. HIDO were planted at

  20. Groundwater impacts on surface water quality and nutrient loads in lowland polder catchments: monitoring the greater Amsterdam area

    Science.gov (United States)

    Yu, Liang; Rozemeijer, Joachim; van Breukelen, Boris M.; Ouboter, Maarten; van der Vlugt, Corné; Broers, Hans Peter

    2018-01-01

    The Amsterdam area, a highly manipulated delta area formed by polders and reclaimed lakes, struggles with high nutrient levels in its surface water system. The polders receive spatially and temporally variable amounts of water and nutrients via surface runoff, groundwater seepage, sewer leakage, and via water inlets from upstream polders. Diffuse anthropogenic sources, such as manure and fertiliser use and atmospheric deposition, add to the water quality problems in the polders. The major nutrient sources and pathways have not yet been clarified due to the complex hydrological system in lowland catchments with both urban and agricultural areas. In this study, the spatial variability of the groundwater seepage impact was identified by exploiting the dense groundwater and surface water monitoring networks in Amsterdam and its surrounding polders. A total of 25 variables (concentrations of total nitrogen (TN), total phosphorus (TP), NH4, NO3, HCO3, SO4, Ca, and Cl in surface water and groundwater, N and P agricultural inputs, seepage rate, elevation, land-use, and soil type) for 144 polders were analysed statistically and interpreted in relation to sources, transport mechanisms, and pathways. The results imply that groundwater is a large source of nutrients in the greater Amsterdam mixed urban-agricultural catchments. The groundwater nutrient concentrations exceeded the surface water environmental quality standards (EQSs) in 93 % of the polders for TP and in 91 % for TN. Groundwater outflow into the polders thus adds to nutrient levels in the surface water. High correlations (R2 up to 0.88) between solutes in groundwater and surface water, together with the close similarities in their spatial patterns, confirmed the large impact of groundwater on surface water chemistry, especially in the polders that have high seepage rates. Our analysis indicates that the elevated nutrient and bicarbonate concentrations in the groundwater seepage originate from the decomposition of

  1. Groundwater impacts on surface water quality and nutrient loads in lowland polder catchments: monitoring the greater Amsterdam area

    Directory of Open Access Journals (Sweden)

    L. Yu

    2018-01-01

    Full Text Available The Amsterdam area, a highly manipulated delta area formed by polders and reclaimed lakes, struggles with high nutrient levels in its surface water system. The polders receive spatially and temporally variable amounts of water and nutrients via surface runoff, groundwater seepage, sewer leakage, and via water inlets from upstream polders. Diffuse anthropogenic sources, such as manure and fertiliser use and atmospheric deposition, add to the water quality problems in the polders. The major nutrient sources and pathways have not yet been clarified due to the complex hydrological system in lowland catchments with both urban and agricultural areas. In this study, the spatial variability of the groundwater seepage impact was identified by exploiting the dense groundwater and surface water monitoring networks in Amsterdam and its surrounding polders. A total of 25 variables (concentrations of total nitrogen (TN, total phosphorus (TP, NH4, NO3, HCO3, SO4, Ca, and Cl in surface water and groundwater, N and P agricultural inputs, seepage rate, elevation, land-use, and soil type for 144 polders were analysed statistically and interpreted in relation to sources, transport mechanisms, and pathways. The results imply that groundwater is a large source of nutrients in the greater Amsterdam mixed urban–agricultural catchments. The groundwater nutrient concentrations exceeded the surface water environmental quality standards (EQSs in 93 % of the polders for TP and in 91 % for TN. Groundwater outflow into the polders thus adds to nutrient levels in the surface water. High correlations (R2 up to 0.88 between solutes in groundwater and surface water, together with the close similarities in their spatial patterns, confirmed the large impact of groundwater on surface water chemistry, especially in the polders that have high seepage rates. Our analysis indicates that the elevated nutrient and bicarbonate concentrations in the groundwater seepage originate

  2. Thermodynamic characteristics of solutions of Bu4NI in dimethylsulfoxide over a wide concentration range

    International Nuclear Information System (INIS)

    Safonova, L.P.; Shmukler, L.Eh.; Kolker, A.M.

    2008-01-01

    The integral heats of solution of Bu 4 NI in dimethylsulfoxide (DMSO) were measured at 298.15, 313.15, and 328.15 K and concentrations from dilute to saturation. The standard enthalpies and heat capacities of solution and solvation of Bu 4 NI in DMSO at various temperatures and the C-bar p 0 (Bu 4 N + ) value at 298.15 K were calculated. The obtained and literature data were used to consider the influence of the nature of solvents on Δ sol H m (Bu 4 NI) and of the electrolyte on Δ sol H m in dimethylsulfoxide at 298.15 K. The dynamic viscosity and density of the Bu 4 NI-DMSO system were determined at various concentrations and temperatures. The Eyring equation was used to calculate the activation energy of viscous flow at all the concentrations studied [ru

  3. Effect of subalpine canopy removal on snowpack, soil solution, and nutrient export, Fraser Experimental Forest, CO

    Science.gov (United States)

    Stottlemyer, R.; Troendle, C.A.

    1999-01-01

    proportionally greater than water flux. Increased subsurface flow accounted for most of the increase in non-limiting nutrient loss. For limiting nutrients, loss of plant uptake and increased shallow subsurface flow accounted for the greater loss. Seasonal ion concentration patterns in streamwater and subsurface flow were similar.Research on the effects of vegetation manipulation on snowpack, soil water, and streamwater chemistry and flux has been underway at the Fraser Experimental Forest (FEF), CO, since 1982. Greater than 95% of FEF snowmelt passes through watersheds as subsurface flow where soil processes significantly alter meltwater chemistry. To better understand the mechanisms accounting for annual variation in watershed streamwater ion concentration and flux with snowmelt, we studied subsurface water flow, its ion concentration, and flux in conterminous forested and clear cut plots. Repetitive patterns in subsurface flow and chemistry were apparent. Control plot subsurface flow chemistry had the highest ion concentrations in late winter and fall. When shallow subsurface flow occurred, its Ca2+, SO42-, and HCO3- concentrations were lower and K+ higher than deep flow. The percentage of Ca2+, NO3-, SO42-, and HCO3- flux in shallow depths was less and K+ slightly greater than the percentage of total flow. Canopy removal increased precipitation reaching the forest floor by about 40%, increased peak snowpack water equivalent (SWE) > 35%, increased the average snowpack Ca2+, NO3-, and NH4+ content, reduced the snowpack K+ content, and increased the runoff four-fold. Clear cutting doubled the percentage of subsurface flow at shallow depths, and increased K+ concentration in shallow subsurface flow and NO3- concentrations in both shallow and deep flow. The percentage change in total Ca2+, SO42-, and HCO3- flux in shallow depths was less than the change in water flux, while that of K+ and NO3- flux was greater. Relative to the control, in the clear cut the percentage of total Ca

  4. Effects of mountain agriculture on nutrient cycling at upstream watersheds

    Science.gov (United States)

    Lin, T.-C.; Shaner, P. L.; Wang, L.-J.; Shih, Y.-T.; Wang, C.-P.; Huang, G.-H.; Huang, J.-C.

    2015-05-01

    The expansion of agriculture to rugged mountains can exacerbate negative impacts of agriculture activities on ecosystem function. In this study, we monitored streamwater chemistry of four watersheds with varying proportions of agricultural lands (0.4, 3, 17, 22%) and rainfall chemistry of two of the four watersheds at Feitsui Reservoir Watershed in northern Taiwan to examine the effects of agriculture on watershed nutrient cycling. We found that the greater the proportions of agricultural lands, the higher the ion concentrations, which is evident for fertilizer-associated ions (NO3-, K+) but not for ions that are rich in soils (SO42-, Ca2+, Mg2+), suggesting that agriculture enriched fertilizer-associated nutrients in streamwater. The watershed with the highest proportion of agricultural lands had higher concentrations of ions in rainfall and lower nutrient retention capacity (i.e. higher output-input ratio of ions) compared to the relatively pristine watershed, suggesting that agriculture can influence atmospheric deposition of nutrients and a system's ability to retain nutrients. Furthermore, we found that a forested watershed downstream of agricultural activities can dilute the concentrations of fertilizer-associated ions (NO3-, K+) in streamwater by more than 70%, indicating that specific landscape configurations help mitigate nutrient enrichment to aquatic systems. We estimated that agricultural lands at our study site contributed approximately 400 kg ha-1 yr-1 of NO3-N and 260 kg ha-1 yr-1 of PO4-P output via streamwater, an order of magnitude greater than previously reported around the globe and can only be matched by areas under intense fertilizer use. Furthermore, we re-constructed watershed nutrient fluxes to show that excessive leaching of N and P, and additional loss of N to the atmosphere via volatilization and denitrification, can occur under intense fertilizer use. In summary, this study demonstrated the pervasive impacts of agriculture activities

  5. A smart market for nutrient credit trading to incentivize wetland construction

    Science.gov (United States)

    Raffensperger, John F.; Prabodanie, R. A. Ranga; Kostel, Jill A.

    2017-03-01

    Nutrient trading and constructed wetlands are widely discussed solutions to reduce nutrient pollution. Nutrient markets usually include agricultural nonpoint sources and municipal and industrial point sources, but these markets rarely include investors who construct wetlands to sell nutrient reduction credits. We propose a new market design for trading nutrient credits, with both point source and non-point source traders, explicitly incorporating the option of landowners to build nutrient removal wetlands. The proposed trading program is designed as a smart market with centralized clearing, done with an optimization. The market design addresses the varying impacts of runoff over space and time, and the lumpiness of wetland investments. We simulated the market for the Big Bureau Creek watershed in north-central Illinois. We found that the proposed smart market would incentivize wetland construction by assuring reasonable payments for the ecosystem services provided. The proposed market mechanism selects wetland locations strategically taking into account both the cost and nutrient removal efficiencies. The centralized market produces locational prices that would incentivize farmers to reduce nutrients, which is voluntary. As we illustrate, wetland builders' participation in nutrient trading would enable the point sources and environmental organizations to buy low cost nutrient credits.

  6. Fluid motion and solute distribution around sinking aggregates I : Small-scale fluxes and heterogeneity of nutrients in the pelagic environment

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Ploug, H.; Thygesen, Uffe Høgsbro

    2001-01-01

    in the ambient water. We described the fluid flow and solute distribution around a sinking aggregate by solving the Navier- Stokes' equations and the advection-diffusion equations numerically. The model is valid for Reynolds numbers characteristic of marine snow, up to Re = 20. The model demonstrates...... in its wake, where solute concentration is either elevated (leaking substances) or depressed (consumed substances) relative to ambient concentration. Such plumes may impact the nutrition of osmotrophs. For example, based on published solubilization rates of aggregates we describe the amino acid plume...

  7. Hydroponic Crop Production using Recycled Nutrients from Inedible Crop Residues

    Science.gov (United States)

    Garland, Jay L.; Mackowiak, Cheryl L.; Sager, John C.

    1993-01-01

    The coupling of plant growth and waste recycling systems is an important step toward the development of bioregenerative life support systems. This research examined the effectiveness of two alternative methods for recycling nutrients from the inedible fraction (residue) of candidate crops in a bioregenerative system as follows: (1) extraction in water, or leaching, and (2) combustion at 550 C, with subsequent reconstitution of the ash in acid. The effectiveness of the different methods was evaluated by (1) comparing the percent recovery of nutrients, and (2) measuring short- and long-term plant growth in hydroponic solutions, based on recycled nutrients.

  8. Nutrient concentrations, loads, and yields in the Eucha-Spavinaw Basin, Arkansas and Oklahoma, 2002-09

    Science.gov (United States)

    Esralew, Rachel A.; Tortorelli, Robert L.

    2010-01-01

    The city of Tulsa, Oklahoma, uses Lake Eucha and Spavinaw Lake in the Eucha-Spavinaw Basin in northwestern Arkansas and northeastern Oklahoma for public water supply. The city has spent millions of dollars over the last decade to eliminate taste and odor problems in the drinking water from the Eucha-Spavinaw system, which may be attributable to blue-green algae. Increases in the algal biomass in the lakes may be attributable to increases in nutrient concentrations in the lakes and in the waters feeding the lakes. The U.S. Geological Survey, in cooperation with the City of Tulsa, investigated and summarized total nitrogen and total phosphorus concentrations in water samples and provided estimates of nitrogen and phosphorus loads, yields, and flow-weighted concentrations during base flow and runoff for two streams discharging to Lake Eucha for the period January 2002 through December 2009. This report updates a previous report that used data from water-quality samples collected from January 2002 through December 2006. Based on the results from the Mann-Whitney statistical test, unfiltered total nitrogen concentrations were significantly greater in runoff water samples than in base-flow water samples collected from Spavinaw Creek near Maysville and near Cherokee City, Arkansas; Spavinaw Creek near Colcord, Oklahoma, and Beaty Creek near Jay, Oklahoma. Nitrogen concentrations in runoff water samples collected from all stations generally increased with increasing streamflow. Nitrogen concentrations in base-flow and runoff water samples collected in Spavinaw Creek significantly increased from the station furthest upstream (near Maysville) to the Sycamore station and then significantly decreased from the Sycamore station to the station furthest downstream (near Colcord). Nitrogen concentrations in base-flow and runoff water samples collected from Beaty Creek were significantly less than base-flow and runoff water samples collected from Spavinaw Creek. Based on the results

  9. {delta}{sup 15}N of seagrass leaves for monitoring anthropogenic nutrient increases in coral reef ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Yamamuro, M.; Kayanne, H.; Yamano, H

    2003-04-01

    In a coral reef environment, a slight increase in dissolved inorganic nitrogen (DIN;{>=}1.0 {mu}M) can alter the ecosystem via macroalgal blooms. We collected seagrass leaves from the tropical and subtropical Pacific Ocean in five countries and examined the interactions between nutrient concentrations (C, N, P), molar ratios of nutrients, and {delta}{sup 15}N to find a possible indicator of the DIN conditions. Within most sites, the concentrations of nutrients and their molar ratios showed large variations owing to species-specific values. On the other hand, almost identical {delta}{sup 15}N values were found in seagrass leaves of several species at each site. The correlations between {delta}{sup 15}N and nutrient concentrations and between {delta}{sup 15}N and molar ratios of nutrients suggested that nutrient availability did not affect the {delta}{sup 15}N value of seagrass leaves by altering the physiological condition of the plants. Increases in {delta}{sup 15}N of seagrass leaves mostly matched increases in DIN concentrations in the bottom water. We suggest that {delta}{sup 15}N in seagrass leaves can be a good tool to monitor time-integrated decrease/increase of DIN concentrations at a site, both in the water column and the interstitial water.

  10. Soil-plant nutrient interactions in two mangrove areas at Southern Brazil

    Directory of Open Access Journals (Sweden)

    Ana Paula Lang Martins Madi

    2016-01-01

    The results exposed that the nutritional state of the mangrove species is different and independent form the soil attributes in which they grow. Few correlations were found among leaf nutrient concentrations and soil attributes, suggesting differential selective nutrient uptake among species.

  11. Circulating fat-soluble vitamin concentrations and nutrient composition of aquatic prey eaten by American oystercatchers (Haematopus palliatus) in the southeastern United States

    Science.gov (United States)

    Carlson-Bremer, Daphne; Norton, Terry M.; Sanders, Felicia J.; Winn, Brad; Spinks, Mark D.; Glatt, Batsheva A.; Mazzaro, Lisa; Jodice, Patrick G.R.; Chen, Tai C.; Dierenfeld, Ellen S.

    2014-01-01

    The American oystercatcher (Haematopus palliatus palliatus) is currently listed as a species of high concern by the United States Shorebird Conservation Plan. Because nutritional status directly impacts overall health and reproduction of individuals and populations, adequate management of a wildlife population requires intimate knowledge of a species' diet and nutrient requirements. Fat-soluble vitamin concentrations in blood plasma obtained from American oystercatchers and proximate, vitamin, and mineral composition of various oystercatcher prey species were determined as baseline data to assess nutritional status and nutrient supply. Bird and prey species samples were collected from the Cape Romain region, South Carolina, USA, and the Altamaha River delta islands, Georgia, USA, where breeding populations appear relatively stable in recent years. Vitamin A levels in blood samples were higher than ranges reported as normal for domestic avian species, and vitamin D concentrations were lower than anticipated based on values observed in poultry. Vitamin E levels were within ranges previously reported for avian groups with broadly similar feeding niches such as herons, gulls, and terns (eg, aquatic/estuarine/marine). Prey species (oysters, mussels, clams, blood arks [Anadara ovalis], whelks [Busycon carica], false angel wings [Petricola pholadiformis]) were similar in water content to vertebrate prey, moderate to high in protein, and moderate to low in crude fat. Ash and macronutrient concentrations in prey species were high compared with requirements of carnivores or avian species. Prey items analyzed appear to meet nutritional requirements for oystercatchers, as estimated by extrapolation from domestic carnivores and poultry species; excesses, imbalances, and toxicities—particularly of minerals and fat-soluble vitamins—may warrant further investigation.

  12. FOLIAR NUTRIENT CONTENTS AND FRUIT YIELD IN CUSTARD APPLE PROGENIES

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Lima e Silva

    2009-01-01

    Full Text Available Foliar nutrient contents are evaluated in several fruit trees with many objectives. Leaf analysis constitutes a way of evaluating the nutritional requirements of crops. Due to the positive impact that fertilizers have on crop yields, researchers frequently try to evaluate the correlations between yield and foliar nutrient contents. This work's objective was to present fruit yields from the 4th to the 6th cropping seasons, evaluate foliar nutrient contents (on the 5th cropping season, and estimate the correlations between these two groups of traits for 20 half-sibling custard apple tree progenies. The progenies were evaluated in a random block design with five replicates and four plants per plot. One hundred leaves were collected from the middle third of the canopy (in height of each of four plants in each plot. The leaves were collected haphazardly, i.e., in a random manner, but without using a drawing mechanism. In the analysis of variance, the nutrient concentrations in the leaves from plants of each plot were represented by the average of four plants in the plot. Fruit yield in the various progenies did not depend on cropping season; progeny A4 was the most productive. No Spearman correlation was found between leaf nutrient concentrations and fruit yield. Increased nutrient concentrations in the leaves were progeny-dependent, i.e., with regard to Na (progenies FE5 and JG1, Ca (progeny A4, Mg (progeny SM7, N (progeny A3, P (progeny M, and K contents (progeny JG3. Spearman's correlation was negative between Na-Mg, Na-Ca, and Mg-P contents, and positive between Mg-Ca and N-K contents.

  13. Concentrations and loads of nutrients in the tributaries of the Lake Okeechobee watershed, south-central Florida, water years 2004-2008

    Science.gov (United States)

    Byrne, Michael J.; Wood, Molly S.

    2011-01-01

    Lake Okeechobee in south-central Florida is the second largest freshwater lake in the contiguous United States. Excessive phosphorus loading, harmful high and low water levels, and rapid expansion of non-native vegetation have threatened the health of the lake in recent decades. A study was conducted to monitor discharge and nutrient concentrations from selected tributaries into Lake Okeechobee and to evaluate nutrient loads. The data analysis was performed at 16 monitoring stations from December 2003 to September 2008. Annual and seasonal discharge measured at monitoring stations is affected by rainfall. Hurricanes affected three wet years (2004, 2005, and the latter part of 2008) and resulted in substantially greater discharge than the drought years of 2006, 2007, and the early part of 2008. Rainfall supplies about 50 percent of the water to Lake Okeechobee, discharge from the Kissimmee River supplies about 25 percent, and discharge from tributaries and groundwater seepage along the lake perimeter collectively provide the remaining 25 percent. Annually, tributary discharge from basins located on the west side of the Kissimmee River is about 5 to 6 times greater than that from basins located on the east side. For the purposes of this study, the basins on the east side of the Kissimmee River are called "priority basins" because of elevated phosphorus concentrations, while those on the west side are called "nonpriority" basins. Total annual discharge in the non-priority basins ranged from 245,000 acre-feet (acre-ft) in 2007 to 1,322,000 acre-ft in 2005, while annual discharge from the priority basins ranged from 41,000 acre-ft in 2007 to 219,000 acre-ft in 2005. Mean total phosphorus concentrations ranged from 0.10 to 0.54 milligrams per liter (mg/L) at the 16 tributaries during 2004–2008. Mean concentrations were significantly higher at priority basin sites than at non-priority basin sites, particularly at Arbuckle Creek and C 41A Canal. Concentrations of organic

  14. Effects of a specific blend of essential oils on apparent nutrient digestion, rumen fermentation and rumen microbial populations in sheep fed a 50:50 alfalfa hay:concentrate diet

    Directory of Open Access Journals (Sweden)

    N. Khateri

    2017-03-01

    Full Text Available Objective An experiment was conducted to investigate the effects of a specific mixture of essential oils (MEO, containing thyme, clove and cinnamon EO, on rumen microbial fermentation, nutrient apparent digestibility and blood metabolites in fistulated sheep. Methods Six sheep fitted with ruminal fistulas were used in a repeated measurement design with two 24-d periods to investigate the effect of adding MEO at 0 (control, 0.8, and 1.6 mL/d on apparent nutrient digestibility, rumen fermentation characteristics, rumen microbial population and blood chemical metabolites. Animals were fed with a 50:50 alfalfa hay:concentrate diet. Results Ruminal pH, total volatile fatty acids (VFA concentration, molar proportion of individual VFA, acetate: propionate ratio and methane production were not affected with MEO. Relative to the control, Small peptides plus amino acid nitrogen and large peptides nitrogen concentration in rumen fluid were not affected with MEO supplementation; while, rumen fluid ammonia nitrogen concentration at 0 and 6 h after morning feeding in sheep fed with 1.6 mL/d of MEO was lower (p<0.05 compared to the control and 0.8 mL/d of MEO. At 0 h after morning feeding, ammonia nitrogen concentration was higher (p<0.05 in sheep fed 0.8 mL/d of MEO relative to 1.6 mL/d and control diet. Ruminal protozoa and hyper ammonia producing (HAP bacteria counts were not affected by addition of MEO in the diet. Relative to the control, no changes were observed in the red and white blood cells, hemoglobin, hematocrit, glucose, beta-hydroxybutyric acid, cholesterol, total protein, albumin, blood urea nitrogen and aspartate aminotransferase and alanine aminotransferase concentration. Apparent total tract digestibility of dry matter, crude proten, organic matter, and neutral detergent fiber were not influenced by MEO supplementation. Conclusion The results of the present study suggested that supplementation of MEO may have limited effects on apparent

  15. Phytoremediation to remove nutrients and improve eutrophic stormwaters using water lettuce (Pistia stratiotes L.).

    Science.gov (United States)

    Lu, Qin; He, Zhenli L; Graetz, Donald A; Stoffella, Peter J; Yang, Xiaoe

    2010-01-01

    Water quality impairment by nutrient enrichment from agricultural activities has been a concern worldwide. Phytoremediation technology using aquatic plants in constructed wetlands and stormwater detention ponds is increasingly applied to remediate eutrophic waters. The objectives of this study were to evaluate the effectiveness and potential of water lettuce (Pistia stratiotes L.) in removing nutrients including nitrogen (N) and phosphorus (P) from stormwater in the constructed water detention systems before it is discharged into the St. Lucie Estuary, an important surface water system in Florida, using phytoremediation technologies. In this study, water lettuce (P. stratiotes) was planted in the treatment plots of two stormwater detention ponds (East and West Ponds) in 2005-2007 and water samples from both treatment and control plots were weekly collected and analyzed for water quality properties including pH, electrical conductivity, turbidity, suspended solids, and nutrients (N and P). Optimum plant density was maintained and plant samples were collected monthly and analyzed for nutrient contents. Water quality in both ponds was improved, as evidenced by decreases in water turbidity, suspended solids, and nutrient concentrations. Water turbidity was decreased by more than 60%. Inorganic N (NH(4) (+) and NO(3) (-)) concentrations in treatment plots were more than 50% lower than those in control plots (without plant). Reductions in both PO(4) (3-) and total P were approximately 14-31%, as compared to the control plots. Water lettuce contained average N and P concentrations of 17 and 3.0 g kg(-1), respectively, and removed 190-329 kg N ha(-1) and 25-34 kg P ha(-1) annually. Many aquatic plants have been used to remove nutrients from eutrophic waters but water lettuce proved superior to most other plants in nutrient removal efficiency, owing to its rapid growth and high biomass yield potential. However, the growth and nutrient removal potential are affected by many

  16. Nutrient and dissolved organic carbon removal from water using mining and metallurgical by-products.

    Science.gov (United States)

    Wendling, Laura A; Douglas, Grant B; Coleman, Shandel; Yuan, Zheng

    2012-05-15

    Excess nutrient input to water bodies frequently results in algal blooms and development of oxygen deficient conditions. Mining or metallurgical by-products can potentially be utilised as filtration media within water treatment systems such as constructed wetlands, permeable reactive barriers, or drain liners. These materials may offer a cost-effective solution for the removal of nutrients and dissolved organic carbon (DOC) from natural waters. This study investigated steel-making, alumina refining (red mud and red sand) and heavy mineral processing by-products, as well as the low-cost mineral-based material calcined magnesia, in laboratory column trials. Influent water and column effluents were analysed for pH and flow rate, alkalinity, nutrient species and DOC, and a range of major cations and anions. In general, by-products with high Ca or Mg, and to a lesser extent those with high Fe content, were well-suited to nutrient and DOC removal from water. Of the individual materials examined, the heavy mineral processing residue neutralised used acid (NUA) exhibited the highest sorption capacity for P, and removed the greatest proportions of all N species and DOC from influent water. In general, NUA and mixtures containing NUA, particularly those with calcined magnesia or red mud/red sand were the most effective in removing nutrients and DOC from influent water. Post-treatment effluents from columns containing NUA and NUA/steel-making by-product, NUA/red sand and NUA/calcined magnesia mixtures exhibited large reductions in DOC, P and N concentrations and exhibited a shift in nutrient ratios away from potential N- and Si-limitation and towards potential P-limitation. If employed as part of a large-scale water treatment scheme, use of these mining and metallurgical by-products for nutrient removal could result in reduced algal biomass and improved water quality. Identification and effective implementation of mining by-products or blends thereof in constructed wetlands

  17. Impacts of waste from concentrated animal feeding operations on water quality

    Science.gov (United States)

    Burkholder, J.; Libra, B.; Weyer, P.; Heathcote, S.; Kolpin, D.; Thorne, P.S.; Wichman, M.

    2007-01-01

    Waste from agricultural livestock operations has been a long-standing concern with respect to contamination of water resources, particularly in terms of nutrient pollution. However, the recent growth of concentrated animal feeding operations (CAFOs) presents a greater risk to water quality because of both the increased volume of waste and to contaminants that may be present (e.g., antibiotics and other veterinary drugs) that may have both environmental and public health importance. Based on available data, generally accepted livestock waste management practices do not adequately or effectively protect water resources from contamination with excessive nutrients, microbial pathogens, and pharmaceuticals present in the waste. Impacts on surface water sources and wildlife have been documented in many agricultural areas in the United States. Potential impacts on human and environmental health from long-term inadvertent exposure to water contaminated with pharmaceuticals and other compounds are a growing public concern. This workgroup, which is part of the Conference on Environmental Health Impacts of Concentrated Animal Feeding Operations: Anticipating Hazards-Searching for Solutions, identified needs for rigorous ecosystem monitoring in the vicinity of CAFOs and for improved characterization of major toxicants affecting the environment and human health. Last, there is a need to promote and enforce best practices to minimize inputs of nutrients and toxicants from CAFOs into freshwater and marine ecosystems.

  18. Effects of potential and concentration of bicarbonate solution on stress corrosion cracking of annealed carbon steel

    International Nuclear Information System (INIS)

    Haruna, Takumi; Zhu, Liehong; Murakami, Makoto; Shibata, Toshio

    2000-01-01

    Effects of potential and concentration of bicarbonate on stress corrosion cracking (SCC) of annealed SM 400 B carbon steel has been investigated in bicarbonate solutions at 343 K. The surface of annealed specimen had decarburized layer of about 0. 5 mm thickness. A potentiostatic slow strain rate testing apparatus equipped with a charge coupled device camera system was employed to evaluate SCC susceptibility from the viewpoint of the crack behavior. In a constant bicarbonate concentration of 1 M, cracks were observed in the potential range from -800 to 600 mV Ag/ A gCl . and especially, the initiation and the propagation of the cracks were accelerated at -600 mV. At a constant potential of -600 mV, cracks were observed in the concentration range from 0.001 to 1 M, and the initiation and the propagation of the cracks were suppressed as the concentration decreased. Polarization curves for the decarburized surface were measured with two different scan rates. High SCC susceptibility may be expected in the potential range where the difference between the two current densities is large. It was found in this system that the potential with the maximum difference in the current density was -600 mV for 1 M bicarbonate solution, and the potential increased with a decrease in the concentration of bicarbonate. This means that an applied potential of -600 mV provides the highest SCC susceptibility for 1 M bicarbonate solution, and that the SCC susceptibility decreases as the concentration decreases. These findings support the dependence of the actual SCC behavior on the potential and the concentration of bicarbonate. (author)

  19. Performance test of nutrient control equipment for hydroponic plants

    Science.gov (United States)

    Rahman, Nurhaidar; Kuala, S. I.; Tribowo, R. I.; Anggara, C. E. W.; Susanti, N. D.

    2017-11-01

    Automatic control equipment has been made for the nutrient content in irrigation water for hydroponic plants. Automatic control equipment with CCT53200E conductivity controller to nutrient content in irrigation water for hydroponic plants, can be used to control the amount of TDS of nutrient solution in the range of TDS numbers that can be set according to the range of TDS requirements for the growth of hydroponically cultivated crops. This equipment can minimize the work time of hydroponic crop cultivators. The equipment measurement range is set between 1260 ppm up to 1610 ppm for spinach plants. Caisim plants were included in this experiment along with spinach plants with a spinach plants TDS range. The average of TDS device is 1450 ppm, while manual (conventional) is 1610 ppm. Nutrient solution in TDS controller has pH 5,5 and temperature 29,2 °C, while manual is pH 5,6 and temperature 31,3 °C. Manually treatment to hydroponic plant crop, yields in an average of 39.6 grams/plant, greater than the yield of spinach plants with TDS control equipment, which is in an average of 24.6 grams / plant. The yield of caisim plants by manual treatment is in an average of 32.3 grams/crop, less than caisim crop yields with TDS control equipment, which is in an average of 49.4 grams/plant.

  20. Reeds as indicators of nutrient enrichment in a small temporarily ...

    African Journals Online (AJOL)

    Nutrient (NH4 and SRP) concentrations decreased from the bank towards the main estuary channel, suggesting that nutrients introduced into the estuary in groundwater and surface runoff were taken up by the fringe of reeds. The roots, rhizomes, stems and leaves of Phragmites at the site with the greatest Phragmites ...

  1. Influence of nutrient restriction and melatonin supplementation of pregnant ewes on maternal and fetal pancreatic digestive enzymes and insulin-containing clusters.

    Science.gov (United States)

    Keomanivong, F E; Lemley, C O; Camacho, L E; Yunusova, R; Borowicz, P P; Caton, J S; Meyer, A M; Vonnahme, K A; Swanson, K C

    2016-03-01

    Primiparous ewes (n=32) were assigned to dietary treatments in a 2×2 factorial arrangement to determine effects of nutrient restriction and melatonin supplementation on maternal and fetal pancreatic weight, digestive enzyme activity, concentration of insulin-containing clusters and plasma insulin concentrations. Treatments consisted of nutrient intake with 60% (RES) or 100% (ADQ) of requirements and melatonin supplementation at 0 (CON) or 5 mg/day (MEL). Treatments began on day 50 of gestation and continued until day 130. On day 130, blood was collected under general anesthesia from the uterine artery, uterine vein, umbilical artery and umbilical vein for plasma insulin analysis. Ewes were then euthanized and the pancreas removed from the ewe and fetus, trimmed of mesentery and fat, weighed and snap-frozen until enzyme analysis. In addition, samples of pancreatic tissue were fixed in 10% formalin solution for histological examination including quantitative characterization of size and distribution of insulin-containing cell clusters. Nutrient restriction decreased (P⩽0.001) maternal pancreatic mass (g) and α-amylase activity (U/g, kU/pancreas, U/kg BW). Ewes supplemented with melatonin had increased pancreatic mass (P=0.03) and α-amylase content (kU/pancreas and U/kg BW). Melatonin supplementation decreased (P=0.002) maternal pancreatic insulin-positive tissue area (relative to section of tissue), and size of the largest insulin-containing cell cluster (P=0.04). Nutrient restriction decreased pancreatic insulin-positive tissue area (P=0.03) and percent of large (32 001 to 512 000 µm2) and giant (⩾512 001 µm2) insulin-containing cell clusters (P=0.04) in the fetus. Insulin concentrations in plasma from the uterine vein, umbilical artery and umbilical vein were greater (P⩽0.01) in animals receiving 100% requirements. When comparing ewes to fetuses, ewes had a greater percentage of medium insulin-containing cell clusters (2001 to 32 000 µm2) while fetuses

  2. Effects of nanoparticle heating on the structure of a concentrated aqueous salt solution.

    Science.gov (United States)

    Sindt, Julien O; Alexander, Andrew J; Camp, Philip J

    2017-12-07

    The effects of a rapidly heated nanoparticle on the structure of a concentrated aqueous salt solution are studied using molecular dynamics simulations. A diamond-like nanoparticle of radius 20 Å is immersed in a sodium-chloride solution at 20% above the experimental saturation concentration and equilibrated at T = 293 K and P = 1 atm. The nanoparticle is then rapidly heated to several thousand degrees Kelvin, and the system is held under isobaric-isoenthalpic conditions. It is observed that after 2-3 ns, the salt ions are depleted far more than water molecules from a proximal zone 15-25 Å from the nanoparticle surface. This leads to a transient reduction in molality in the proximal zone and an increase in ion clustering in the distal zone. At longer times, ions begin to diffuse back into the proximal zone. It is speculated that the formation of proximal and distal zones, and the increase in ion clustering, plays a role in the mechanism of nonphotochemical laser-induced nucleation.

  3. Effects of nanoparticle heating on the structure of a concentrated aqueous salt solution

    Science.gov (United States)

    Sindt, Julien O.; Alexander, Andrew J.; Camp, Philip J.

    2017-12-01

    The effects of a rapidly heated nanoparticle on the structure of a concentrated aqueous salt solution are studied using molecular dynamics simulations. A diamond-like nanoparticle of radius 20 Å is immersed in a sodium-chloride solution at 20% above the experimental saturation concentration and equilibrated at T = 293 K and P = 1 atm. The nanoparticle is then rapidly heated to several thousand degrees Kelvin, and the system is held under isobaric-isoenthalpic conditions. It is observed that after 2-3 ns, the salt ions are depleted far more than water molecules from a proximal zone 15-25 Å from the nanoparticle surface. This leads to a transient reduction in molality in the proximal zone and an increase in ion clustering in the distal zone. At longer times, ions begin to diffuse back into the proximal zone. It is speculated that the formation of proximal and distal zones, and the increase in ion clustering, plays a role in the mechanism of nonphotochemical laser-induced nucleation.

  4. Biodesulfurization of vanadium-bearing titanomagnetite concentrates and pH control of bioleaching solution

    Science.gov (United States)

    Liu, Xiao-rong; Jiang, Sheng-cai; Liu, Yan-jun; Li, Hui; Wang, Hua-jun

    2013-10-01

    Vanadium-bearing titanomagnetite concentrates were desulfurized with Acidithiobacillus ferrooxidans ( A. ferrooxidans). The sulfur content of the concentrates was reduced from 0.69wt% to 0.14wt% after bioleaching for 15 d with a 10% pulp density at 30°C. Maintaining a stable pH value during biodesulfurization was critical because of high acid consumption, resulting from a combination of nonoxidative and oxidative dissolution of pyrrhotite in acid solution. It is discovered that the citric acid-disodium hydrogen phosphate buffer of pH 2.0 can control the solution pH value smoothly in the optimal range of 2.0-3.0 for A. ferrooxidans growth. Using the buffer in the volume fraction range of 5.0%-15.0% stimulates A. ferrooxidans growth and improves the biodesulfurization efficiency. Compared with the buffer-free control case, the maximum increase of biodesulfurization rate is 29.7% using a 10.0vol% buffer. Bioleaching provides an alternative process for desulfurization of vanadium-bearing titanomagnetite ores.

  5. System-Wide Water Resources Program Nutrient Sub-Model (SWWRP-NSM) Version 1.1

    Science.gov (United States)

    2008-09-01

    in solution Thrm by the mixing of rainwater with soil solution . A rate-limited mass transfer at the soil overland flow interface controls the...dissolved nutrient transfer from soil solution to overland flow, once formed. The mass transfer coefficient will be affected by many factors including

  6. Removal of nitrate, ammonia and phosphate from aqueous solutions in packed bed filter using biochar augmented sand media

    Directory of Open Access Journals (Sweden)

    El Hanandeh Ali

    2017-01-01

    Full Text Available Nutrients from wastewater are a major source of pollution because they can cause significant impact on the ecosystem. Accordingly, it is important that the nutrient concentrations are kept to admissible levels to the receiving environment. Often regulatory limits are set on the maximum allowable concentrations in the effluent. Therefore, wastewater must be treated to meet safe levels of discharge. In this study, laboratory investigation of the efficiency of packed bed filters to remove nitrate, ammonium and phosphate from aqueous solutions were conducted. Sand and sand augmented with hydrochloric acid treated biochar (SBC were used as packing media. Synthetic wastewater solution was prepared with PO43−, NO3−, NH4+ concentrations 20, 10, 50 mg/L, respectively. Each experiment ran for a period of five days; samples from the effluent were collected on alternate days. All experiments were duplicated. Over the experiment period, the average removal efficiency of PO43−, NO3−, NH4+ were 99.2%, 72.9%, 96.7% in the sand packed columns and 99.2%, 82.3%, 97.4% in the SBC packed columns, respectively. Although, the presence of biochar in the packing media had little effect on phosphate and ammonium removal, it significantly improved nitrate removal.

  7. Two tales of legacy effects on stream nutrient behaviour

    Science.gov (United States)

    Bieroza, M.; Heathwaite, A. L.

    2017-12-01

    Intensive agriculture has led to large-scale land use conversion, shortening of flow pathways and increased loads of nutrients in streams. This legacy results in gradual build-up of nutrients in agricultural catchments: in soil for phosphorus (biogeochemical legacy) and in the unsaturated zone for nitrate (hydrologic legacy), controlling the water quality in the long-term. Here we investigate these effects on phosphorus and nitrate stream concentrations using high-frequency (10-5 - 100 Hz) sampling with in situ wet-chemistry analysers and optical sensors. Based on our 5 year study, we observe that storm flow responses differ for both nutrients: phosphorus shows rapid increases (up to 3 orders of magnitude) in concentrations with stream flow, whereas nitrate shows both dilution and concentration effects with increasing flow. However, the range of nitrate concentrations change is narrow (up to 2 times the mean) and reflects chemostatic behaviour. We link these nutrient responses with their dominant sources and flow pathways in the catchment. Nitrate from agriculture (with the peak loading in 1983) is stored in the unsaturated zone of the Penrith Sandstone, which can reach up to 70 m depth. Thus nitrate legacy is related to a hydrologic time lag with long travel times in the unsaturated zone. Phosphorus is mainly sorbed to soil particles, therefore it is mobilised rapidly during rainfall events (biogeochemical legacy). The phosphorus stream response will however depend on how well connected is the stream to the catchment sources (driven by soil moisture distribution) and biogeochemical activity (driven by temperature), leading to both chemostatic and non-chemostatic responses, alternating on a storm-to-storm and seasonal basis. Our results also show that transient within-channel storage is playing an important role in delivery of phosphorus, providing an additional time lag component. These results show, that consistent agricultural legacy in the catchment (high

  8. [Optimization of benzalkonium chloride concentration in 0.0015% tafluprost ophthalmic solution from the points of ocular surface safety and preservative efficacy].

    Science.gov (United States)

    Asada, Hiroyuki; Takaoka-Shichijo, Yuko; Nakamura, Masatsugu; Kimura, Akio

    2010-06-01

    Optimization of benzalkonium chloride (alkyl dimethylbenzylammonium chloride: BAK) concentration as preservative in 0.0015% tafluprost ophthalmic solution (Tapros 0.0015% ophthalmic solution), an anti-glaucoma medicine, was examined from the points of ocular surface safety and preservative efficacy. BAKC(12), which is dodecyl dimethylbenzylammonium chloride, and BAKmix, which is the mixture of dodecyl, tetradecyl and hexadecyl dimethylbenzylammonium chloride were used in this study. The effects of BAKC(12) concentrations and the BAK types, BAKC(12) and BAKmix, in tafluprost ophthalmic solution on ocular surface safety were evaluated using the in vitro SV 40-immobilized human corneal epithelium cell line (HCE-T). Following treatments of Tafluprost ophthalmic solutions with BAKC(12), its concentration dependency was observed on cell viability of HCE-T. The cell viability of HCE-T after treatment of these solutions with 0.001% to 0.003% BAKC(12) for 5 minutes were the same level as that after treatment of the solution without BAK. Tafluprost ophthalmic solution with 0.01% BAKC(12) was safer for the ocular surface than the same solution with 0.01% BAKmix. Preservatives-effectiveness tests of tafluprost ophthalmic solutions with various concentrations of BAKC(12) were performed according to the Japanese Pharmacopoeia (JP), and solutions with more than 0.0005% BAKC(12) conformed to JP criteria. It was concluded that 0.0005% to 0.003% of BAKC(12) in tafluprost ophthalmic solution was optimal, namely, well-balanced from the points of ocular surface safety and preservative efficacy.

  9. Nutrients in the nexus

    Science.gov (United States)

    Davidson, Eric A.; Niphong, Rachel; Ferguson, Richard B.; Palm, Cheryl; Osmond, Deanna L.; Baron, Jill S.

    2016-01-01

    Synthetic nitrogen (N) fertilizer has enabled modern agriculture to greatly improve human nutrition during the twentieth century, but it has also created unintended human health and environmental pollution challenges for the twenty-first century. Averaged globally, about half of the fertilizer-N applied to farms is removed with the crops, while the other half remains in the soil or is lost from farmers’ fields, resulting in water and air pollution. As human population continues to grow and food security improves in the developing world, the dual development goals of producing more nutritious food with low pollution will require both technological and socio-economic innovations in agriculture. Two case studies presented here, one in sub-Saharan Africa and the other in Midwestern United States, demonstrate how management of nutrients, water, and energy is inextricably linked in both small-scale and large-scale food production, and that science-based solutions to improve the efficiency of nutrient use can optimize food production while minimizing pollution. To achieve the needed large increases in nutrient use efficiency, however, technological developments must be accompanied by policies that recognize the complex economic and social factors affecting farmer decision-making and national policy priorities. Farmers need access to affordable nutrient supplies and support information, and the costs of improving efficiencies and avoiding pollution may need to be shared by society through innovative policies. Success will require interdisciplinary partnerships across public and private sectors, including farmers, private sector crop advisors, commodity supply chains, government agencies, university research and extension, and consumers.

  10. Effects of different combinations of Hoagland's solution and Azolla ...

    African Journals Online (AJOL)

    ALAN

    2013-04-17

    Apr 17, 2013 ... hydroponic cultures containing different compositions of hydroponic solutions were evaluated in ... (Hoagland's solution minus N solution excluding Azolla; ..... nutrient deficiencies on photosynthesis and respiration in spinach.

  11. Mycorrhiza formation and nutrient concentration in leeks (¤Allium porrum¤) in relation to previous crop and cover crop management on high P soils

    DEFF Research Database (Denmark)

    Sørensen, J.N.; Larsen, J.; Jakobsen, I.

    2005-01-01

    An improved integration of mycorrhizas may increase the sustainability in plant production. Two strategies for increasing the soil inoculum potential of mycorrhizal fungi were investigated in field experiments with leeks: Pre-cropping with mycorrhizal main crops and pre-establishment of mycorrhizal......, increased the colonization of leek roots by mycorrhizal fungi. During early growth stages, this increase was 45-95% relative to no cover crop. However, cover cropping did not significantly increase nutrient concentration or growth. These variables were not influenced by the time of cover crop incorporation...... or tillage treatments. Differences in colonization, nutrient uptake and plant growth diminished during the growing period and at the final harvest date, the effects on plant production disappeared. High soil P level or high soil inoculum level was most likely responsible for the limited response of increased...

  12. Phytoplankton and nutrient dynamics in Winyah Bay, SC.

    Science.gov (United States)

    Boneillo, G. E.; Brooks, S. S.; Brown, S. L.; Woodford, K. M.; Wright, C. R.

    2016-02-01

    Winyah Bay is a coastal plain estuary located in South Carolina that has been classified for a moderate risk of Eutrophication by NOAA. Winyah Bay receives freshwater input from four rivers, the Waccamaw, Sampit, Black, and Pee Dee Rivers. The Waccamaw, Sampit and Black River are blackwater systems that discharge elevated amounts of colored dissolved organic matter. During the summer and fall of 2015, bioassay experiments were performed to simultaneously examine both light and nutrient (nitrogen & phosphate) limitation throughout Winyah Bay. Sampling stations near the mouth of the Waccamaw and Sampit Rivers showed that phytoplankton were light limited in the late summer instead of nutrient limited. These stations were located in the industrialized area of the bay and typically had the highest nutrient concentrations and highest turbidity, with Secchi depths typically less than 0.5 meters. Results indicated that phytoplankton may be nitrogen limited near the mouth of Winyah Bay, where nutrient concentrations and turbidity were observed to be lower than locations further upstream. There was also an observed dissolved oxygen and pH gradient during the summer of 2015. Dissolved oxygen levels less than 4.0 mg/L were routinely observed near the industrialized head of the estuary and corresponded with lower pH values.

  13. Influence of Concentration and Agitation of Sodium Hypochlorite and Peracetic Acid Solutions on Tissue Dissolution.

    Science.gov (United States)

    Tanomaru-Filho, Mário; Silveira, Bruna Ramos Franco; Martelo, Roberta Bosso; Guerreiro-Tanomaru, Juliane Maria

    2015-11-01

    To evaluated the tissue dissolution of sodium hypochlorite (NaOCl) and peracetic acid (PA) solutions at different concentrations, with or without ultrasonic agitation. The following solutions were analyzed: 2.5% NaOCl, 0.5, 1 and 2% PA, 1% PA associated with 6.5% hydrogen peroxide (HP) and saline. Fragments of bovine pulp tissue with 25 ± 2g mg were immersed into test tubes containing 4 mL of the solutions for 10 minutes. In the groups with agitation, pulp tissues were submitted to 2 cycles of 1 minute of ultrasonic agitation. The specimens were weighed after the removal from the solutions. The percentage of mass loss was calculated according to the difference of mass before and after exposure to solutions. Data were submitted to ANOVA and Tukey tests (p Peracetic acid solution has pulp tissue dissolution. However, this ability is lower than 2.5% NaOCl solution. The sodium hypochlorite solution shows higher ability to dissolve tissue than PA.

  14. Bromfenac ophthalmic solution 0.09 %: human aqueous humor concentration detected by high-performance liquid chromatography.

    Science.gov (United States)

    Macrì, Angelo; Vagge, Aldo; Salis, Annalisa; Fucile, Carmen; Marini, Valeria; Martelli, Antonietta; Giuffrida, Sebastiano; Iester, Michele; Damonte, Gianluca; Mattioli, Francesca

    2017-04-01

    The purpose of this study was to evaluate the aqueous humor concentrations of bromfenac ophthalmic solution 0.09 % in patients undergoing phacoemulsification. Patients requiring cataract extraction received one drop (50 µL) of bromfenac 0.09 % solution in the eye to be operated, before bedtime the day before surgery or the morning of the surgery. The last administration was recorded. At the time of paracentesis, an aqueous humor sample was collected with a 30-gauge needle attached to a TB syringe and was later analyzed by high-performance liquid chromatography for drug concentration. 188 treated volunteers and 48 control, untreated, subjects were included in the study. The mean aqueous concentration of bromfenac in the treated group was 37.60 ± 68.86 and 0 nM (nmol/L) in the control group (p < 0.0001). Correlation coefficient in bromfenac group between time elapsed from instillation and drug concentration was -0.16 (p not significant). Bromfenac showed properties of good penetration and stable concentration in aqueous humor up to about 12 h after instillation.

  15. Nutrients in the Western Wadden Sea: Freshwater Input Versus Internal Recycling

    NARCIS (Netherlands)

    Leote, C.; Mulder, L.; Philippart, C.J.; Epping, E.

    2016-01-01

    At present, phosphorus (P) is seen as the main limiting nutrient for phytoplankton growth in the western Wadden Sea. Six cruises were performed for water sampling at selected stations covering a full tidal cycle for later determination of dissolved and particulate nutrient concentrations. The major

  16. Nutrients and heavy metal distribution in thermally treated pig manure

    DEFF Research Database (Denmark)

    Kuligowski, Ksawery; Poulsen, Tjalfe G.; Stoholm, Peder

    2008-01-01

    Ash from pig manure treated by combustion and thermal gasification was characterized and compared in terms of nutrient, i.e., potassium (K), phosphorus (P) and heavy metal, i.e., cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and zinc (Zn) contents. Total nutrient and metal concentrations...... that ash from gasified manure contained more water-extractable K in comparison with combusted manure whereas the opposite was the case with respect to P. Heavy metals Ni, Cr and Cd were present in higher concentrations in the fine particle size fractions (

  17. Nutrient acquisition across a dietary shift: fruit feeding butterflies crave amino acids, nectivores seek salt.

    Science.gov (United States)

    Ravenscraft, Alison; Boggs, Carol L

    2016-05-01

    Evolutionary dietary shifts have major ecological consequences. One likely consequence is a change in nutrient limitation-some nutrients become more abundant in the diet, others become more scarce. Individuals' behavior should change accordingly to match this new limitation regime: they should seek out nutrients that are deficient in the new diet. We investigated the relationship between diet and responses to nutrients using adult Costa Rican butterflies with contrasting feeding habits, testing the hypothesis that animals will respond more positively to nutrients that are scarcer in their diets. Via literature searches and our own data, we showed that nitrogen and sodium are both at lower concentration in nectar than in fruit. We therefore assessed butterflies' acceptance of sodium and four nitrogenous compounds that ranged in complexity from inorganic nitrogen (ammonium chloride) to protein (albumin). We captured wild butterflies, offered them aqueous solutions of each substance, and recorded whether they accepted (drank) or rejected each substance. Support for our hypothesis was mixed. Across the sexes, frugivores were four times more likely to accept amino acids (hydrolyzed casein) than nectivores, in opposition to expectation. In males, nectivores accepted sodium almost three times more frequently than frugivores, supporting expectations. Together, these results suggest that in butterflies, becoming frugivorous is associated with an increased receptivity to amino acids and decreased receptivity to sodium. Nectivory and frugivory are widespread feeding strategies in organisms as diverse as insects, birds, and bats; our results suggest that these feeding strategies may put different pressures on how animals fulfill their nutritional requirements.

  18. Dynamics of Reactive Microbial Hotspots in Concentration Gradient.

    Science.gov (United States)

    Hubert, A.; Farasin, J.; Tabuteau, H.; Dufresne, A.; Meheust, Y.; Le Borgne, T.

    2017-12-01

    In subsurface environments, bacteria play a major role in controlling the kinetics of a broad range of biogeochemical reactions. In such environments, nutrients fluxes and solute concentrations needed for bacteria metabolism may be highly variable in space and intermittent in time. This can lead to the formation of reactive hotspots where and when conditions are favorable to particular microorganisms, hence inducing biogeochemical reaction kinetics that differ significantly from those measured in homogeneous model environments. To investigate the impact of chemical gradients on the spatial structure and temporal dynamics of subsurface microorganism populations, we develop microfluidic cells allowing for a precise control of flow and chemical gradient conditions, as well as quantitative monitoring of the bacteria's spatial distribution and biofilm development. Using the non-motile Escherichia coli JW1908-1 strain and Gallionella capsiferriformans ES-2 as model organisms, we investigate the behavior and development of bacteria over a range of single and double concentration gradients in the concentrations of nutrients, electron donors and electron acceptors. We measure bacterial activity and population growth locally in precisely known hydrodynamic and chemical environments. This approach allows time-resolved monitoring of the location and intensity of reactive hotspots in micromodels as a function of the flow and chemical gradient conditions. We compare reactive microbial hotspot dynamics in our micromodels to classic growth laws and well-known growth parameters for the laboratory model bacteria Escherichia coli.We also discuss consequences for the formation and temporal dynamics of biofilms in the subsurface.

  19. Mass loss and nutrient concentrations of buried wood as a function of organic matter removal, soil compaction, and vegetation control in a regenerating oak-pine forest

    Science.gov (United States)

    Felix Ponder; John M. Kabrick; Mary Beth Adams; Deborah S. Page-Dumroese; Marty F. Jurgensen

    2017-01-01

    Mass loss and nutrient concentrations of northern red oak (Quercus rubra) and white oak (Q. alba) wood stakes were measured 30 months after their burial in the upper 10 cm of soil in a regenerating forest after harvesting and soil disturbance. Disturbance treatments were two levels of organic matter (OM) removal (only...

  20. Response of algal metrics to nutrients and physical factors and identification of nutrient thresholds in agricultural streams

    Science.gov (United States)

    Black, R.W.; Moran, P.W.; Frankforter, J.D.

    2011-01-01

    Many streams within the United States are impaired due to nutrient enrichment, particularly in agricultural settings. The present study examines the response of benthic algal communities in agricultural and minimally disturbed sites from across the western United States to a suite of environmental factors, including nutrients, collected at multiple scales. The first objective was to identify the relative importance of nutrients, habitat and watershed features, and macroinvertebrate trophic structure to explain algal metrics derived from deposition and erosion habitats. The second objective was to determine if thresholds in total nitrogen (TN) and total phosphorus (TP) related to algal metrics could be identified and how these thresholds varied across metrics and habitats. Nutrient concentrations within the agricultural areas were elevated and greater than published threshold values. All algal metrics examined responded to nutrients as hypothesized. Although nutrients typically were the most important variables in explaining the variation in each of the algal metrics, environmental factors operating at multiple scales also were important. Calculated thresholds for TN or TP based on the algal metrics generated from samples collected from erosion and deposition habitats were not significantly different. Little variability in threshold values for each metric for TN and TP was observed. The consistency of the threshold values measured across multiple metrics and habitats suggest that the thresholds identified in this study are ecologically relevant. Additional work to characterize the relationship between algal metrics, physical and chemical features, and nuisance algal growth would be of benefit to the development of nutrient thresholds and criteria. ?? 2010 The Author(s).

  1. Thermosolutal convection in saturated porous enclosure with concentrated energy and solute sources

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Di; Zhao, Fu-Yun; Tang, Guang-Fa [College of Civil Engineering, Hunan University, Changsha (China)

    2008-01-15

    Double diffusive natural convection within a vertical porous enclosure with localized heating and salting from one side is numerically studied by the finite element based finite volume method. In the formulation of the problem, use is made of the Darcy model, which allows the slip boundary condition on a solid wall to be satisfied. Comparisons with benchmark solutions for natural convection in fluid saturated porous enclosures are first presented to validate the code. Following that, an extensive series of numerical simulations is conducted in the range of -55 {<=} N {<=} + 55 and 0.125 {<=} L {<=} 0.875, where N and L are the buoyancy ratio and the element location, respectively. Streamlines, heatlines, masslines, isotherms and iso-concentrations in the system are produced to illustrate the flow structure transition from solutal dominated opposing to thermal dominated and solutal dominated aiding flows, respectively. The computed average Nusselt and Sherwood numbers provide guidance for locating the heating and salting element. (author)

  2. Thermosolutal convection in saturated porous enclosure with concentrated energy and solute sources

    Energy Technology Data Exchange (ETDEWEB)

    Liu Di [College of Civil Engineering, Hunan University, Changsha (China)], E-mail: liudi66@163.com; Zhao Fuyun [College of Civil Engineering, Hunan University, Changsha (China)], E-mail: zfycfdnet@163.com; Tang Guangfa [College of Civil Engineering, Hunan University, Changsha (China)], E-mail: gftangcfd@163.com

    2008-01-15

    Double diffusive natural convection within a vertical porous enclosure with localized heating and salting from one side is numerically studied by the finite element based finite volume method. In the formulation of the problem, use is made of the Darcy model, which allows the slip boundary condition on a solid wall to be satisfied. Comparisons with benchmark solutions for natural convection in fluid saturated porous enclosures are first presented to validate the code. Following that, an extensive series of numerical simulations is conducted in the range of -55 {<=} N {<=} + 55 and 0.125 {<=} L {<=} 0.875, where N and L are the buoyancy ratio and the element location, respectively. Streamlines, heatlines, masslines, isotherms and iso-concentrations in the system are produced to illustrate the flow structure transition from solutal dominated opposing to thermal dominated and solutal dominated aiding flows, respectively. The computed average Nusselt and Sherwood numbers provide guidance for locating the heating and salting element.

  3. Nutrient content of biomass components of Hamlin sweet orange trees

    Directory of Open Access Journals (Sweden)

    Mattos Jr. Dirceu

    2003-01-01

    Full Text Available The knowledge of the nutrient distribution in trees is important to establish sound nutrient management programs for citrus production. Six-year-old Hamlin orange trees [Citrus sinensis (L. Osb.] on Swingle citrumelo [Poncirus trifoliata (L. Raf. x Citrus paradisi Macfad.] rootstock, grown on a sandy Entisol in Florida were harvested to investigate the macro and micronutrient distributions of biomass components. The biomass of aboveground components of the tree represented the largest proportion of the total. The distribution of the total tree dry weight was: fruit = 30.3%, leaf = 9.7%, twig = 26.1%, trunk = 6.3%, and root = 27.8%. Nutrient concentrations of recent mature leaves were in the adequate to optimal range as suggested by interpretation of leaf analysis in Florida. Concentrations of Ca in older leaves and woody tissues were much greater than those in the other parts of the tree. Concentrations of micronutrients were markedly greater in fibrous root as compared to woody roots. Calcium made up the greatest amount of nutrient in the citrus tree (273.8 g per tree, followed by N and K (234.7 and 181.5 g per tree, respectively. Other macronutrients comprised about 11% of the total nutrient content of trees. The contents of various nutrients in fruits were: N = 1.20, K = 1.54, P = 0.18, Ca = 0.57, Mg = 0.12, S = 0.09, B = 1.63 x 10-3, Cu = 0.39 x 10-3, Fe = 2.1 x 10-3, Mn = 0.38 10-3, and Zn = 0.40 10-3 (kg ton-1. Total contents of N, K, and P in the orchard corresponded to 66.5, 52.0, and 8.3 kg ha-1, respectively, which were equivalent to the amounts applied annually by fertilization.

  4. Determination of dew absorption by coffee plant through deuterium concentrations in leaf water

    Energy Technology Data Exchange (ETDEWEB)

    Leopoldo, P R [Faculdade de Ciencias Medicas e Biologicas de Botucatu (Brazil); Salati, E; Matsui, E [Centro de Energia Nuclear na Agricultura, Piracicaba (Brazil)

    1975-12-01

    The effect of dew falling on leaves on the water metabolism of the coffee plant (Coffea arabica) is examined. The use of natural stable isotopes variations in plant physiological studies is demonstrated. Water extracted from leaf samples is analysed by mass spectrometry. Analyses of deuterium concentrations in water extracted from plant leaves, dew and nutrient solutions are made. Determination of changes in deuterium concentration in the water of leaves from plants exposed to dew, compared with leaves not exposed to dew, is carried out. Results show that during daytime there is an enrichment in deuterium in water contained in the leaves, while at night the opposite occurs.

  5. Determination of dew absorption by coffee plant through deuterium concentrations in leaf water

    International Nuclear Information System (INIS)

    Leopoldo, P.R.; Salati, E.; Matsui, E.

    1975-01-01

    The effect of dew falling on leaves on the water metabolism of the coffee plant (Coffea arabica) is examined. The use of natural stable isotopes variations in plant physiological studies is demonstrated. Water extracted from leaf samples is analysed by mass spectrometry. Analyses of deuterium concentrations in water extracted from plant leaves, dew and nutrient solutions are made. Determination of changes in deuterium concentration in the water of leaves from plants exposed to dew, compared with leaves not exposed to dew, is carried out. Results show that during daytime there is an enrichment in deuterium in water contained in the leaves, while at night the opposite occurs [pt

  6. Substitution of common concentrates with by-products modulated ruminal fermentation, nutrient degradation, and microbial community composition in vitro.

    Science.gov (United States)

    Ertl, P; Knaus, W; Metzler-Zebeli, B U; Klevenhusen, F; Khiaosa-Ard, R; Zebeli, Q

    2015-07-01

    A rumen simulation technique was used to evaluate the effects of the complete substitution of a common concentrate mixture (CON) with a mixture consisting solely of by-products from the food industry (BP) at 2 different forage-to-concentrate ratios on ruminal fermentation profile, nutrient degradation, and abundance of rumen microbiota. The experiment was a 2×2 factorial arrangement with 2 concentrate types (CON and BP) and 2 concentrate levels (25 and 50% of diet dry matter). The experiment consisted of 2 experimental runs with 12 fermentation vessels each (n=6 per treatment). Each run lasted for 10d, with data collection on the last 5d. The BP diets had lower starch, but higher neutral detergent fiber (NDF) and fat contents compared with CON. Degradation of crude protein was decreased, but NDF and nonfiber carbohydrate degradation were higher for the BP diets. At the 50% concentrate level, organic matter degradation tended to be lower for BP and CH4 formation per unit of NDF degraded was also lower for BP. The BP mixture led to a higher concentration of propionate and a lower acetate-to-propionate ratio, whereas concentrations of butyrate and caproate decreased. Concentrate type did not affect microbial community composition, except that the abundance of bacteria of the genus Prevotella was higher for BP. Increasing the concentrate level resulted in higher degradation of organic matter and crude protein. At the higher concentrate level, total short-chain fatty acid formation increased and concentrations of isobutyrate and valerate decreased. In addition, at the 50% concentrate level, numbers of protozoa increased, whereas numbers of methanogens, anaerobic fungi, and fibrolytic bacteria decreased. No interaction was noted between the 2 dietary factors on most variables, except that at the higher concentrate level the effects of BP on CH4 and CO2 formation per unit of NDF degraded, crude protein degradation, and the abundance of Prevotella were more prominent. In

  7. Produtividade de rúcula hidropônica cultivada em diferentes épocas e vazões de solução nutritiva Yield of hydroponic rocket cultivated in different seasons and flow rates of nutrient solution

    Directory of Open Access Journals (Sweden)

    Gláucio da C Genuncio

    2011-12-01

    Full Text Available A rúcula é uma das principais hortaliças produzidas no Brasil via hidroponia. Entretanto, além da aplicação de uma solução nutritiva adequada à cultura, torna-se imprescindível o conhecimento e o controle das variáveis intrínsecas ao manejo da solução nutritiva. Assim, o objetivo foi avaliar o acúmulo de biomassa fresca de parte aérea e raiz e a produtividade da rúcula cultivada em três vazões de solução nutritiva em hidroponia NFT, durante seis ciclos de cultivo. Os tratamentos consistiram de três vazões de solução nutritiva, sendo V1= 0,75, V2= 1,00 e V3= 1,50 L min-1. Foram avaliados seis ciclos de cultivo (de julho a dezembro. O delineamento experimental foi de blocos ao acaso com oito repetições. Realizaram-se as colheitas aos 30 dias após o transplante para os canais de hidroponia. O acúmulo de biomassa de parte aérea e de raiz foi maior nos meses de novembro e dezembro, devido a maiores temperaturas em casa de vegetação. Foi observado menor valor de biomassa de parte aérea na menor vazão do sistema. A produtividade da parte aérea e total (parte aérea + raiz foi maior nos meses mais quentes. Observou-se um incremento na produtividade com um aumento da vazão da solução nutritiva nos canais de hidroponia.The rocket is one of the main vegetable crops produced in Brazil through hydroponics. Nevertheless, besides the application of an appropriate nutrient solution for the crop, the knowledge and control of intrinsic variables for the management of the nutrient solution is essential. The accumulation of fresh biomass of the aboveground part, roots and the yield of rocket grown in three flow rates of nutrient solution during six crop cycles was studied. The treatments consisted of three flows rates of nutrient solution, V1= 0.75, V2= 1.00 and V3= 1.50 L min-1. We also evaluated six cycles of cultivation (from July to December. The experimental design was randomized blocks with eight replications. Harvest

  8. Amelioration of boron toxicity in sweet pepper as affected by calcium management under an elevated CO2 concentration.

    Science.gov (United States)

    Piñero, María Carmen; Pérez-Jiménez, Margarita; López-Marín, Josefa; Del Amor, Francisco M

    2017-04-01

    We investigated B tolerance in sweet pepper plants (Capsicum annuun L.) under an elevated CO 2 concentration, combined with the application of calcium as a nutrient management amelioration technique. The data show that high B affected the roots more than the aerial parts, since there was an increase in the shoot/root ratio, when plants were grown with high B levels; however, the impact was lessened when the plants were grown at elevated CO 2 , since the root FW reduction caused by excess B was less marked at the high CO 2 concentration (30.9% less). Additionally, the high B concentration affected the membrane permeability of roots, which increased from 39 to 54% at ambient CO 2 concentration, and from 38 to 51% at elevated CO 2 concentration, producing a cation imbalance in plants, which was differentially affected by the CO 2 supply. The Ca surplus in the nutrient solution reduced the nutritional imbalance in sweet pepper plants produced by the high B concentration, at both CO 2 concentrations. The medium B concentration treatment (toxic according to the literature) did not result in any toxic effect. Hence, there is a need to review the literature on critical and toxic B levels taking into account increases in atmospheric CO 2 .

  9. A comparison of nutrient density scores for 100% fruit juices.

    Science.gov (United States)

    Rampersaud, G C

    2007-05-01

    The 2005 Dietary Guidelines for Americans recommend that consumers choose a variety of nutrient-dense foods. Nutrient density is usually defined as the quantity of nutrients per calorie. Food and nutrition professionals should be aware of the concept of nutrient density, how it might be quantified, and its potential application in food labeling and dietary guidance. This article presents the concept of a nutrient density score and compares nutrient density scores for various 100% fruit juices. One hundred percent fruit juices are popular beverages in the United States, and although they can provide concentrated sources of a variety of nutrients, they can differ considerably in their nutrient profiles. Six methodologies were used to quantify nutrient density and 7 100% fruit juices were included in the analysis: apple, grape, pink grapefruit, white grapefruit, orange, pineapple, and prune. Food composition data were obtained from the USDA National Nutrient Database for Standard Reference, Release 18. Application of the methods resulted in nutrient density scores with a range of values and magnitudes. The relative scores indicated that citrus juices, particularly pink grapefruit and orange juice, were more nutrient dense compared to the other nonfortified 100% juices included in the analysis. Although the methods differed, the relative ranking of the juices based on nutrient density score was similar for each method. Issues to be addressed regarding the development and application of a nutrient density score include those related to food fortification, nutrient bioavailability, and consumer education and behavior.

  10. Nutrient Mass Balance for the Mobile River Basin in Alabama, Georgia, and Mississippi

    Science.gov (United States)

    Harned, D. A.; Harvill, J. S.; McMahon, G.

    2001-12-01

    percent mean). The basins retained from 60 to 87 percent (74 percent mean) of phosphorous inputs. Correlation of basin nutrient output loads and concentrations with the basin inputs and correlation of output loads and concentrations with basin land use were tested using the Spearman rank test. The correlation analysis indicated that higher nitrogen concentrations in the streams are associated with urban areas and higher loads are associated with agriculture; high phosphorus output loads and concentrations are associated with agriculture. Higher nutrient loads in agricultural basins are partly an effect of basin size-- larger basins generate larger nutrient loads. Nutrient loads and concentrations showed no significant correlation to point-source inputs. Nitrogen loads were significantly (p0.5) higher in basins with greater cropland areas. Nitrogen concentrations also increased as residential, commercial, and total urban areas increased. Phosphorus loads were positively correlated with animal-waste inputs, pasture, and total agricultural land. Phosphorus concentrations were highest in basins with the greatest amounts of row-crop agriculture.

  11. Trophic categorization in the Rías Baixas (NW Spain: nutrients in water and in macroalgae

    Directory of Open Access Journals (Sweden)

    Rubén Villares

    2006-03-01

    Full Text Available Marine eutrophication caused by an excess supply of nutrients is a serious problem in many coastal areas throughout the world. In the present study we used the capacity of macroalgae (Ulva and Enteromorpha to integrate the nutrient regime of a water body in order to examine the trophic categorization in the embayments studied. We found that the trophic categorization established based on nutrient levels in macroalgae differed from that established based on concentrations in the water. The waters of the innermost areas of the inlets were the most nutrient enriched; the algae appeared to be more affected by specific local conditions and did not display the gradient of decreasing nutrient concentrations from inner to outer areas that was observed in the water samples. The lack of correspondence between nutrients in the water and in the algae in the present study may have been due to the heterogeneous nutrient conditions found in coastal areas, so that the intertidal algae did not adequately reflect the nutrient levels of the inner zones of the embayments under study.

  12. Soluções nutritivas para cultivo e produção de frutanos em plantas de Vernonia herbacea Nutrient solutions for plant growth and fructan production in Vernonia herbacea

    Directory of Open Access Journals (Sweden)

    Geraldo Rogério Faustini Cuzzuol

    2005-09-01

    Full Text Available O crescimento limitado de rizóforos de Vernonia herbacea (Asteraceae em solução de Hoagland levou à necessidade de estabelecer uma solução nutritiva para o cultivo dessa planta, visando ao incremento da biomassa de seus rizóforos ricos em frutanos. Essa solução (denominada Vernonia, constituída de Ca(NO32.4H2O 2,5 mmol L-1, KNO3 2,3 mmol L-1 , KH2PO4 0,52 mmol L-1, Mg(NO32.6H2O 1,7 mmol L-1 e Na2SO4 1,3 mmol L-1, foi comparada com a de Hoagland nas forças iônicas de 50%, 100% e 200%. Foram realizadas duas avaliações para análise de crescimento e conteúdo de frutanos. As plantas não sobreviveram até os dois meses na solução de Hoagland 200%. A solução Vernonia diluída duas vezes (50% foi a mais eficiente para o incremento de massa seca dos rizóforos e produção de frutanos por planta. Maior crescimento da parte aérea foi verificado nas soluções de Hoagland e Vernonia 100%. Em comparação com a solução de Hoagland, a solução Vernonia é mais pobre em macronutrientes, confirmando a hipótese de que plantas adaptadas a solos oligotróficos são menos exigentes em nutrientes minerais.The limited growth of rhizophores of Vernonia herbacea in Hoagland solution demanded the definition of a nutrient solution for plants of V. herbacea, aiming at the increase of the rhizophore biomass and fructan production. This solution, named Vernonia, is comprised of Ca(NO32.4H2O 2.5 mmol L-1, KNO3 2.3 mmol L-1 , KH2PO4 0.52 mmol L-1, Mg(NO32.6H2O 1.7 mmol L-1 and Na2SO4 1.3 mmol L-1. Its effect on plants was compared to that of Hoagland solution, both with different ionic strengths, 50%, 100% and 200%. The effect of the solutions on plant growth and fructan content was evaluated twice in a six-month period. Plants did not survive up to two months, when cultivated in 200% Hoagland solution. The 50% Vernonia solution was the most effective for rhizophore biomass increase and fructan production per plant. Growth of aerial organs was

  13. A study on prediction of uranium concentration in pregnant solution from in-situ leaching

    International Nuclear Information System (INIS)

    Yi Weiping; Zhou Quan; Yu Yunzhen; Wang Shude; Yang Yihan; Lei Qifeng

    2005-01-01

    The modeling course on prediction of uranium concentration in pregnant solution from in-situ leaching of uranium is described, a mathematical model based on grey system theory is put forward, and a set of computer application software is correspondingly developed. (authors)

  14. Recent land cover history and nutrient retention in riparian wetlands

    Science.gov (United States)

    Hogan, D.M.; Walbridge, M.R.

    2009-01-01

    Wetland ecosystems are profoundly affected by altered nutrient and sediment loads received from anthropogenic activity in their surrounding watersheds. Our objective was to compare a gradient of agricultural and urban land cover history during the period from 1949 to 1997, with plant and soil nutrient concentrations in, and sediment deposition to, riparian wetlands in a rapidly urbanizing landscape. We observed that recent agricultural land cover was associated with increases in Nitrogen (N) and Phosphorus (P) concentrations in a native wetland plant species. Conversely, recent urban land cover appeared to alter receiving wetland environmental conditions by increasing the relative availability of P versus N, as reflected in an invasive, but not a native, plant species. In addition, increases in surface soil Fe content suggests recent inputs of terrestrial sediments associated specifically with increasing urban land cover. The observed correlation between urban land cover and riparian wetland plant tissue and surface soil nutrient concentrations and sediment deposition, suggest that urbanization specifically enhances the suitability of riparian wetland habitats for the invasive species Japanese stiltgrass [Microstegium vimenium (Trinius) A. Camus]. ?? 2009 Springer Science+Business Media, LLC.

  15. Assessment of nutrient retention by Natete wetland Kampala, Uganda

    Science.gov (United States)

    Kanyiginya, V.; Kansiime, F.; Kimwaga, R.; Mashauri, D. A.

    Natete wetland which is located in a suburb of Kampala city in Uganda is dominated by C yperus papyrus and covers an area of approximately 1 km 2. The wetland receives wastewater and runoff from Natete town which do not have a wastewater treatment facility. The main objective of this study was to assess nutrient retention of Natete wetland and specifically to: determine the wastewater flow patterns in the wetland; estimate the nutrient loads into and out of the wetland; determine the nutrient retention by soil, plants and water column in the wetland; and assess the above and belowground biomass density of the dominant vegetation. Soil, water and plant samples were taken at 50 m intervals along two transects cut through the wetland; soil and water samples were taken at 10 cm just below the surface. Physico-chemical parameters namely pH, electrical conductivity and temperature were measured in situ. Water samples were analyzed in the laboratory for ammonium-nitrogen, nitrate-nitrogen, total nitrogen, orthophosphate and total phosphorus. Electrical conductivity ranged between 113 μS/cm and 530 μS/cm and the wastewater flow was concentrated on the eastern side of the wetland. pH varied between 6 and 7, temperature ranged from 19 °C to 24 °C. NH 4-N, NO 3-N, and TN concentrations were retained by 21%, 98%, and 35% respectively. Phosphorus concentration was higher at the outlet of the wetland possibly due to release from sediments and leaching. Nutrient loads were higher at the inlet (12,614 ± 394 kgN/day and 778 ± 159 kgP/day) than the outlet (2368 ± 425 kgN/day and 216 ± 56 kgP/day) indicating retention by the wetland. Plants stored most nutrients compared to soil and water. The belowground biomass of papyrus vegetation in the wetland was higher (1288.4 ± 8.3 gDW/m 2) than the aboveground biomass (1019.7 ± 13.8 gDW/m 2). Plant uptake is one of the important routes of nutrient retention in Natete wetland. It is recommended that harvesting papyrus can be an

  16. Influence de la concentration de la solution nutritive sur la croissance et la nutrition minérale de la tomate

    OpenAIRE

    Morard, Philippe; Caumes, Edith; Silvestre, Jérôme

    2004-01-01

    L’influence de deux concentrations de solution nutritive a été étudiée sur la croissance et la nutrition minérale de la tomate en culture hydroponique sous serre au stade début floraison. La force ionique de la solution nutritive la plus concentrée était de 20.00 meq L–1 (SNC), valeur proche de celle qui est habituellement utilisée pour la culture de la tomate ; celle de la solution diluée (SND) était de 3.25 meq L–1. Pendant les deux semaines de l’expérimentation, la concentration du milieu ...

  17. The thermodynamic characteristics of solutions of Bu4NI in dimethylsulfoxide over a wide concentration range

    Science.gov (United States)

    Safonova, L. P.; Shmukler, L. E.; Kolker, A. M.

    2008-05-01

    The integral heats of solution of Bu4NI in dimethylsulfoxide (DMSO) were measured at 298.15, 313.15, and 328.15 K and concentrations from dilute to saturation. The standard enthalpies and heat capacities of solution and solvation of Bu4NI in DMSO at various temperatures and the bar C_p^o (Bu_4 N^ + ) value at 298.15 K were calculated. The obtained and literature data were used to consider the influence of the nature of solvents on Δsol H m (Bu4NI) and of the electrolyte on Δsol H m in dimethylsulfoxide at 298.15 K. The dynamic viscosity and density of the Bu4NI-DMSO system were determined at various concentrations and temperatures. The Eyring equation was used to calculate the activation energy of viscous flow at all the concentrations studied.

  18. Radiation crosslinking of methylcellulose and hydroxyethylcellulose in concentrated aqueous solutions

    International Nuclear Information System (INIS)

    Wach, Radoslaw A.; Mitomo, Hiroshi; Nagasawa, Naotsugu; Yoshii, Fumio

    2003-01-01

    The effects of ionizing radiation on aqueous solutions of cellulose ethers, methylcellulose (MC) and hydroxyethylcellulose (HEC) were investigated. The well-established knowledge states that cellulose and its derivatives belong to degrading type of polymers. However, in our study intermolecular crosslinking initiated by gamma rays or electron beam leaded to the formation of insoluble gel. This is an opposite effect of irradiation to the degradation. Paste-like form of the initial specimen, i.e. concentration 20-30%, when water plasticizes the bulk of polymer; and a high dose rate were favorable for hydrogel formation. Gel fraction up to 60% and 70% was obtained from solutions of HEC and MC, respectively. Produced hydrogels swell markedly in aqueous media by imbibing and holding the solvent. Radiation parameters of irradiation, such as yields of degradation and crosslinking and the gelation dose, were evaluated by sol-gel analysis on the basis of Charlesby-Rosiak equation. Despite of the crosslinked structure, obtained hydrogels can be included into the group of biodegradable materials. They undergo decomposition by the action of cellulase enzyme or microorganisms from compost

  19. STUDY OF CHEMICAL INTERACTION OF MAGNESIA CEMENT WITH HIGH CONCENTRATION MAGNESIUM CHLORIDE SOLUTIONS

    Directory of Open Access Journals (Sweden)

    DEREVIANKO V. N.

    2015-10-01

    Full Text Available Problem statement. In activating MgO by electrolyte salts, as a result of formation of non water-resist magnesium silicate hydrate are obtained the durable cement stone having the low water-resist. I. P. Vyrodov considers [9; 5], that magnesia cement curing in mixing with sufficiently concentrated (C > 20 % solutions MgCl2 is caused with the crystallization of oxyhydrochloride composition: 3MgO∙MgCl2∙11Н2О, 5MgO∙MgCl2∙13Н2О and 7MgO∙MgCl2∙15Н2О. In the lower concentration parts of MgCl2 solution is formed a transitional compound of Mg[(OHnCl2-n] with isomorphous Mg(OH2 structure. At very low Cl concentration only Mg(OH2 is practically formed. Purpose. The Formation of water-resist magnesium silicate hydrates for obtaining of fast curing and solid structure of the magnesia stone. Conclusion. The dependence of the formation of the magnesia stone from the ratio (MgO/MgCl2 of the magnesia cement (MgO and the magnesium chloride solution (MgCl2 of different density has been identified in order to obtain the best content for oxyhydrochloride 3MgO•MgCl2•11Н2О, 5MgO•MgCl2•13Н2О and magnesium hydroxide (Mg(OH2. In putting into the system MgO∙–∙H2О of the silicic acid or fine ground quartz grains with size of less than 20 – 30 microns, over 1 month for the magnesium silicate hydrates formation is needed, where from 2 to 5 % of the total number of newgrowths are created. The study is proved by the expert opinion, that magnesium silicate hydrates do not have binding properties, unlike calcium silicate hydrates, and the main role in the system curing is played with the Mg(OH2 gel recrystallization, which provides the acceptable stone strength (R ≈ 30MPa in a few years. It has been also established, that in mixing of cement with low concentration MgO solutions of less than 1,5 mol/l (or 13% 1,1g/sm3, the final product in the stone structure is Mg(OH2. With increasing the sealer (MgCl2 solution there is formed by turn in

  20. Combined Influence of Landscape Composition and Nutrient Inputs on Lake Trophic Structure

    Science.gov (United States)

    The concentration of chlorophyll a is a measure of the biological productivity of a lake and is largely (but not exclusively) determined by available nutrients. As nutrient inputs increase, productivity increases and lakes transition from low trophic state (e.g. oligotrophic) to...