Liquid nitrogen dewar for protein crystal growth

Science.gov (United States)

2001-01-01

Gaseous Nitrogen Dewar apparatus developed by Dr. Alex McPherson of the University of California, Irvine for use aboard Mir and the International Space Station allows large quantities of protein samples to be crystallized in orbit. The specimens are contained either in plastic tubing (heat-sealed at each end). Biological samples are prepared with a precipitating agent in either a batch or liquid-liquid diffusion configuration. The samples are then flash-frozen in liquid nitrogen before crystallization can start. On orbit, the Dewar is placed in a quiet area of the station and the nitrogen slowly boils off (it is taken up by the environmental control system), allowing the proteins to thaw to begin crystallization. The Dewar is returned to Earth after one to four months on orbit, depending on Shuttle flight opportunities. The tubes then are analyzed for crystal presence and quality

Improved Eco-Friendly Recombinant Anabaena sp. Strain PCC7120 with Enhanced Nitrogen Biofertilizer Potential▿

Science.gov (United States)

Chaurasia, Akhilesh Kumar; Apte, Shree Kumar

2011-01-01

Photosynthetic, nitrogen-fixing Anabaena strains are native to tropical paddy fields and contribute to the carbon and nitrogen economy of such soils. Genetic engineering was employed to improve the nitrogen biofertilizer potential of Anabaena sp. strain PCC7120. Constitutive enhanced expression of an additional integrated copy of the hetR gene from a light-inducible promoter elevated HetR protein expression and enhanced functional heterocyst frequency in the recombinant strain. The recombinant strain displayed consistently higher nitrogenase activity than the wild-type strain and appeared to be in homeostasis with compatible modulation of photosynthesis and respiration. The enhanced combined nitrogen availability from the recombinant strain positively catered to the nitrogen demand of rice seedlings in short-term hydroponic experiments and supported better growth. The engineered strain is stable, eco-friendly, and useful for environmental application as nitrogen biofertilizer in paddy fields. PMID:21057013

Improved eco-friendly recombinant Anabaena sp. strain PCC7120 with enhanced nitrogen biofertilizer potential.

Science.gov (United States)

Chaurasia, Akhilesh Kumar; Apte, Shree Kumar

2011-01-01

Photosynthetic, nitrogen-fixing Anabaena strains are native to tropical paddy fields and contribute to the carbon and nitrogen economy of such soils. Genetic engineering was employed to improve the nitrogen biofertilizer potential of Anabaena sp. strain PCC7120. Constitutive enhanced expression of an additional integrated copy of the hetR gene from a light-inducible promoter elevated HetR protein expression and enhanced functional heterocyst frequency in the recombinant strain. The recombinant strain displayed consistently higher nitrogenase activity than the wild-type strain and appeared to be in homeostasis with compatible modulation of photosynthesis and respiration. The enhanced combined nitrogen availability from the recombinant strain positively catered to the nitrogen demand of rice seedlings in short-term hydroponic experiments and supported better growth. The engineered strain is stable, eco-friendly, and useful for environmental application as nitrogen biofertilizer in paddy fields.

Gaseous Matter

CERN Document Server

Angelo, Joseph A

2011-01-01

aseous Matter focuses on the many important discoveries that led to the scientific interpretation of matter in the gaseous state. This new, full-color resource describes the basic characteristics and properties of several important gases, including air, hydrogen, helium, oxygen, and nitrogen. The nature and scope of the science of fluids is discussed in great detail, highlighting the most important scientific principles upon which the field is based. Chapters include:. Gaseous Matter An Initial Perspective. Physical Characteristics of Gases. The Rise of the Science of Gases. Kinetic Theory of

Nitrogen nutrition effects on development, growth and nitrogen accumulation of vegetables

NARCIS (Netherlands)

Biemond, H.

1995-01-01

In order to be able to match nitrogen supply and nitrogen requirement of vegetable crops, insight is necessary in the responses to nitrogen of important processes of growth and development. This study focused on effects of amount of nitrogen applied and fractionation of nitrogen supply on

[Effects of water deficit and nitrogen fertilization on winter wheat growth and nitrogen uptake].

Science.gov (United States)

Qi, You-Ling; Zhang, Fu-Cang; Li, Kai-Feng

2009-10-01

Winter wheat plants were cultured in vitro tubes to study their growth and nitrogen uptake under effects of water deficit at different growth stages and nitrogen fertilization. Water deficit at any growth stages could obviously affect the plant height, leaf area, dry matter accumulation, and nitrogen uptake. Jointing stage was the most sensitive stage of winter wheat growth to water deficit, followed by flowering stage, grain-filling stage, and seedling stages. Rewatering after the water deficit at seedling stage had a significant compensation effect on winter wheat growth, and definite compensation effect was observed on the biomass accumulation and nitrogen absorption when rewatering was made after the water deficit at flowering stage. Under the same nitrogen fertilization levels, the nitrogen accumulation in root with water deficit at seedling, jointing, flowering, and grain-filling stages was reduced by 25.82%, 55.68%, 46.14%, and 16.34%, and the nitrogen accumulation in aboveground part was reduced by 33.37%, 51.71%, 27.01%, and 2.60%, respectively, compared with no water deficit. Under the same water deficit stages, the nitrogen content and accumulation of winter wheat decreased with decreasing nitrogen fertilization level, i. e., 0.3 g N x kg(-1) FM > 0.2 g N x kg(-1) FM > 0.1 g N x kg(-1) FM. Nitrogen fertilization had obvious regulation effect on winter wheat plant growth, dry matter accumulation, and nitrogen uptake under water stress.

Exogenous trehalose improves growth under limiting nitrogen through upregulation of nitrogen metabolism.

Science.gov (United States)

Lin, Yingchao; Zhang, Jie; Gao, Weichang; Chen, Yi; Li, Hongxun; Lawlor, David W; Paul, Matthew J; Pan, Wenjie

2017-12-19

The trehalose (Tre) pathway has strong effects on growth and development in plants through regulation of carbon metabolism. Altering either Tre or trehalose 6-phosphate (T6P) can improve growth and productivity of plants as observed under different water availability. As yet, there are no reports of the effects of modification of Tre orT6P on plant performance under limiting nutrition. Here we report that nitrogen (N) metabolism is positively affected by exogenous application of Tre in nitrogen-deficient growing conditions. Spraying foliage of tobacco (Nicotiana tabacum) with trehalose partially alleviated symptoms of nitrogen deficiency through upregulation of nitrate and ammonia assimilation and increasing activities of nitrate reductase (NR), glycolate oxidase (GO), glutamine synthetase (GS) and glutamine oxoglutarate aminotransferase (GOGAT) with concomitant changes in ammonium (NH 4 + ) and nitrate (NO 3 - ) concentrations, glutamine and amino acids. Chlorophyll and total nitrogen content of leaves and rates of photosynthesis were increased compared to nitrogen-deficient plants without applied Tre. Total plant biomass accumulation was also higher in Tre -fed nitrogen-deficient plants, with a smaller proportion of dry weight partitioned to roots, compared to nitrogen-deficient plants without applied Tre. Consistent with higher nitrogen assimilation and growth, Tre application reduced foliar starch. Minimal effects of Tre feeding were observed on nitrogen-sufficient plants. The data show, for the first time, significant stimulatory effects of exogenous Tre on nitrogen metabolism and growth in plants growing under deficient nitrogen. Under such adverse conditions metabolism is regulated for survival rather than productivity. Application of Tre can alter this regulation towards maintenance of productive functions under low nitrogen. This has implications for considering approaches to modifying the Tre pathway for to improve crop nitrogen-use efficiency and

Replenishment and mobilization of intracellular nitrogen pools decouples wine yeast nitrogen uptake from growth

OpenAIRE

SANCHO FORNER, MARTA; Alicia Gutiérrez; BELTRAN CASELLAS, GEMMA; José Manuel Guillamon; Jonas Warringer

2016-01-01

Wine yeast capacity to take up nitrogen from the environment and catabolize it to support population growth, fermentation, and aroma production is critical to wine production. Under nitrogen restriction, yeast nitrogen uptake is believed to be intimately coupled to reproduction with nitrogen catabolite repression (NCR) suggested mediating this link. We provide a time- and strain-resolved view of nitrogen uptake, population growth, and NCR activity in wine yeasts. Nitrogen uptake was found to ...

Removal and recovery of nitrogen and sulfur oxides from gaseous mixtures containing them

International Nuclear Information System (INIS)

Cooper, H.B.H.

1984-01-01

A cyclic process for removing lower valence nitrogen oxides from gaseous mixtures includes treating the mixtures with an aqueous media including alkali metal carbonate and alkali metal bicarbonate and a preoxygen oxidant to form higher valence nitrogen oxides and to capture these oxides as alkali metal salts, expecially nitrites and nitrates, in a carbonate/bicarbonate-containing product aqueous media. Highly selective recovery of nitrates in high purity and yield may then follow, as by crystallization, with the carbonate and bicarbonate alkali metal salts strongly increasing the selectivity and yield of nitrates. The product nitrites are converted to nitrates by oxidation after lowering the product aqueous media pH to below about 9. A cyclic process for removing sulfur oxides from gas mixtures includes treating these mixtures includes treating these mixtures with aqueous media including alkali metal carbonate and alkali metal bicarbonate where the ratio of alkali metal to sulfur dioxide is not less than 2. The sulfur values may be recovered from the resulting carbonate/bicarbonate/-sulfite containing product aqueous media as alkali metal sulfate or sulfite salts which are removed by crystallization from the carbonate-containing product aqueous media. As with the nitrates, the carbonate/bicarbonate system strongly increases yield of sulfate or sulfite during crystallization. Where the gas mixtures include both sulfur dioxide and lower valence nitrogen oxides, the processes for removing lower valence nitrogen oxides and sulfur dioxide may be combined into a single removal/recovery system, or may be effected in sequence

Effects of high CO2 on growth and metabolism of Arabidopsis seedlings during growth with a constantly limited supply of nitrogen.

Science.gov (United States)

Takatani, Nobuyuki; Ito, Takuro; Kiba, Takatoshi; Mori, Marie; Miyamoto, Tetsuro; Maeda, Shin-Ichi; Omata, Tatsuo

2014-02-01

Elevated CO2 has been reported to stimulate plant growth under nitrogen-sufficient conditions, but the effects of CO2 on growth in a constantly nitrogen-limited state, which is relevant to most natural habitats of plants, remain unclear. Here, we maintained Arabidopsis seedlings under such conditions by growing a mutant with reduced nitrate uptake activity on a medium containing nitrate as the sole nitrogen source. Under nitrogen-sufficient conditions (i.e. in the presence of ammonium), growth of shoots and roots of both the wild type (WT) and the mutant was increased approximately 2-fold by elevated CO2. Growth stimulation of shoots and roots by elevated CO2 was observed in the WT growing with nitrate as the sole nitrogen source, but in the mutant grown with nitrate, the high-CO2 conditions stimulated only the growth of roots. In the mutant, elevated CO2 caused well-known symptoms of nitrogen-starved plants, including decreased shoot/root ratio, reduced nitrate content and accumulation of anthocyanin, but also had an increased Chl content in the shoot, which was contradictory to the known effect of nitrogen depletion. A high-CO2-responsive change specific to the mutant was not observed in the levels of the major metabolites, although CO2 responses were observed in the WT and the mutant. These results indicated that elevated CO2 causes nitrogen limitation in the seedlings grown with a constantly limited supply of nitrogen, but the Chl content and the root biomass of the plant increase to enhance the activities of both photosynthesis and nitrogen uptake, while maintaining normal metabolism and response to high CO2.

Influence of seed priming and nitrogen application on the growth and development of maize seedlings in saline conditions

International Nuclear Information System (INIS)

Cao, D.; Zhang, Y.; Zhang, Y.; Guan, B.

2018-01-01

Seed priming and nitrogen application can promote plant tolerance and resistance to salt stress. To explore the combined effects of these two factors on the growth of salt-stressed seedlings, four treatments (priming + nitrogen application, PN; priming + no nitrogen application, P; unprimed + nitrogen application, UPN; and control treatment unprimed + no nitrogen application, UP) were applied to evaluate the responses of plant morphology, antioxidase systems, physiological and biochemical parameters of the maize seedlings under different concentrations of salt stress (0, 100, 200, and 300 mM). The results indicated that under salt stress, the priming treatment facilitated the growth of seedlings of root and stems, increased the amount of osmoregulatory substances, and enhanced the antioxidase activity and resistance of the maize seedlings. After nitrogen application during the maize growth stage, the growth of young leaves was greatly promoted along with an increase in the soluble protein and chlorophyll content. The combination of seed priming and nitrogen application significantly improved the plant growth, antioxidase activities and physiological and biochemical parameters. (author)

Growth responses of low-alpine dwarf-shrub heath species to nitrogen deposition and management

International Nuclear Information System (INIS)

Britton, Andrea J.; Fisher, Julia M.

2008-01-01

Nitrogen deposition is a continuing problem in European alpine regions. We hypothesised that, despite climatic limitations, low-alpine Calluna heathland would respond to nitrogen addition with increased shoot growth and flowering and that fire and grazing would modify responses. In a five-year study, 0-50 kg N ha -1 y -1 were added, combined with burning (+/-) and clipping (+/-). Calluna vulgaris responded with increased shoot extension, but effects on flowering were variable. Burning enhanced the positive effect of nitrogen addition and negative effects of clipping. Sub-dominant shrubs generally did not respond to nitrogen. C. vulgaris shoot extension was stimulated by nitrogen addition of 10 kg N ha -1 y -1 (above background) supporting suggestions that alpine heathlands are sensitive to low levels of nitrogen deposition. Increased C. vulgaris growth could negatively impact on important lichen components of this vegetation through increased shading and competition. Climatic factors constrain productivity in this community, but do not prevent rapid responses to nitrogen deposition by some species. - Low levels of N deposition increase productivity in alpine dwarf-shrub heath despite strong climatic constraints

Transgenic plants with enhanced growth characteristics

Energy Technology Data Exchange (ETDEWEB)

Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

2018-01-09

The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

Transgenic plants with enhanced growth characteristics

Energy Technology Data Exchange (ETDEWEB)

Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

2016-09-06

The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

Numerical Simulation and Analysis on Liquid Nitrogen Spray Heat Exchanger

OpenAIRE

Wenjing Ding; Weiwei Shan; Zijuan; Wang; Chao He

2017-01-01

Liquid spray heat exchanger is the critical equipment of temperature regulating system by gaseous nitrogen which realizes the environment temperature in the range of -180 ℃~+180 ℃. Liquid nitrogen is atomized into smaller liquid drops through liquid nitrogen sprayer and then contacts with gaseous nitrogen to be cooled. By adjusting the pressure of liquid nitrogen and gaseous nitrogen, the flowrate of liquid nitrogen is changed to realize the required outlet temperature of heat exchanger. The ...

Gaseous Nitrogen Losses from Tropical Savanna Soils of Northern Australia: Dynamics, Controls and Magnitude of N2O, NO, and N2 emissions

Science.gov (United States)

Werner, C.; Hickler, T.; Hutley, L. B.; Butterbach-Bahl, K.

2014-12-01

Tropical savanna covers a large fraction of the global land area and thus may have a substantial effect on the global soil-atmosphere exchange of nitrogen. The pronounced seasonality of hygric conditions in this ecosystem affects strongly microbial process rates in the soil. As these microbial processes control the uptake, production, and release of nitrogen compounds, it is thought that this seasonality finally leads to strong temporal dynamics and varying magnitudes of gaseous losses to the atmosphere. However, given their areal extent and in contrast to other ecosystems, still few in-situ or laboratory studies exist that assess the soil-atmosphere exchange of nitrogen. We present laboratory incubation results from intact soil cores obtained from a natural savanna site in Northern Australia, where N2O, NO, and N2 emissions under controlled environmental conditions were investigated. Furthermore, in-situ measurements of high temporal resolution at this site recorded with automated static and dynamic chamber systems are discussed (N2O, NO). This data is then used to assess the performance of a process-based biogeochemical model (LandscapeDNDC), and the potential magnitude and dynamics of components of the site-scale nitrogen cycle where no measurements exist (biological nitrogen fixation and nitrate leaching). Our incubation results show that severe nutrient limitation of the soil only allows for very low N2O emissions (0.12 kg N ha-1 yr-1) and even a periodic N2O uptake. Annual NO emissions were estimated at 0.68 kg N ha-1 yr-1, while the release of inert nitrogen (N2) was estimated at 6.75 kg N ha-1 yr-1 (data excl. contribution by pulse emissions). We observed only minor N2O pulse emissions after watering the soil cores and initial rain events of the dry to wet season transition in-situ, but short-lived NO pulse emissions were substantial. Interestingly, some cores exhibited a very different N2O emission potential, indicating a substantial spatial variability of

Martian Soil Plant Growth Experiment: The Effects of Adding Nitrogen, Bacteria, and Fungi to Enhance Plant Growth

Science.gov (United States)

Kliman, D. M.; Cooper, J. B.; Anderson, R. C.

2000-01-01

Plant growth is enhanced by the presence of symbiotic soil microbes. In order to better understand how plants might prosper on Mars, we set up an experiment to test whether symbiotic microbes function to enhance plant growth in a Martian soil simulant.

Enhancing biological nitrogen fixation

Energy Technology Data Exchange (ETDEWEB)

Danso, S.K.A.; Eskew, D.L. (Joint FAO/IAEA Div. of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development, Vienna (Austria))

1984-06-01

Several co-ordinated research programmes (CRPs) conducted by the Soil Fertility, Irrigation and Crop Production Section of the Joint FAO/IAEA Division have concentrated on finding the most efficient way of applying nitrogen fertilizers to various crops, using nitrogen-15 (/sup 15/N) as a tracer. The findings of these studies have been adopted in many countries around the world, resulting in savings of nitrogen fertilizers worth many millions of dollars every year. More recently, the Section's CRPs have focused on enhancing the natural process of biological di-nitrogen fixation. The /sup 15/N isotope technique has proven to be very valuable in studies of the legume-Rhizobium symbiosis, allowing many more experiments than before to be done and yielding much new practical information. The Soils Section is now working to extend the use of the technique to other nitrogen-fixing symbioses.

Low energy consumption method for separating gaseous mixtures and in particular for medium purity oxygen production

Science.gov (United States)

Jujasz, Albert J.; Burkhart, James A.; Greenberg, Ralph

1988-01-01

A method for the separation of gaseous mixtures such as air and for producing medium purity oxygen, comprising compressing the gaseous mixture in a first compressor to about 3.9-4.1 atmospheres pressure, passing said compressed gaseous mixture in heat exchange relationship with sub-ambient temperature gaseous nitrogen, dividing the cooled, pressurized gaseous mixture into first and second streams, introducing the first stream into the high pressure chamber of a double rectification column, separating the gaseous mixture in the rectification column into a liquid oxygen-enriched stream and a gaseous nitrogen stream and supplying the gaseous nitrogen stream for cooling the compressed gaseous mixture, removing the liquid oxygen-enriched stream from the low pressure chamber of the rectification column and pumping the liquid, oxygen-enriched steam to a predetermined pressure, cooling the second stream, condensing the cooled second stream and evaporating the oxygen-enriched stream in an evaporator-condenser, delivering the condensed second stream to the high pressure chamber of the rectification column, and heating the oxygen-enriched stream and blending the oxygen-enriched stream with a compressed blend-air stream to the desired oxygen concentration.

Effects of Nitrogen Application on Growth and Ethanol Yield of Sweet Sorghum [Sorghum bicolor (L. Moench] Varieties

Directory of Open Access Journals (Sweden)

Oluwatoyin Olugbemi

2016-01-01

Full Text Available A study was carried out in two locations, Ilorin (8° 29′ N; 4° 35′ E; about 310 m asl and Ejiba (8° 17′ N; 5° 39′ E; about 246 m asl, at the Southern Guinea Savannah agroecological zone of Nigeria to assess the effect of nitrogen fertilizer on the growth and ethanol yield of four sweet sorghum varieties (NTJ-2, 64 DTN, SW Makarfi 2006, and SW Dansadau 2007. Five N fertilizer levels (0, 40, 80, 120, and 160 kg ha−1 were used in a 4 × 5 factorial experiment, laid out in split-plots arrangement. The application of nitrogen fertilizer was shown to enhance the growth of sweet sorghum as observed in the plant height, LAI, CGR, and other growth indices. Nitrogen fertilizer application also enhanced the ethanol yield of the crop, as variations in growth parameters and ethanol yield were observed among the four varieties studied. The variety SW Dansadau 2007 was observed as the most promising in terms of growth and ethanol yield, and the application of 120 kg N ha−1 resulted in the best ethanol yield at the study area.

Growth responses, biomass partitioning, and nitrogen isotopes of prairie legumes in response to elevated temperature and varying nitrogen source in a growth chamber experiment.

Science.gov (United States)

Whittington, Heather R; Deede, Laura; Powers, Jennifer S

2012-05-01

Because legumes can add nitrogen (N) to ecosystems through symbiotic fixation, they play important roles in many plant communities, such as prairies and grasslands. However, very little research has examined the effect of projected climate change on legume growth and function. Our goal was to study the effects of temperature on growth, nodulation, and N chemistry of prairie legumes and determine whether these effects are mediated by source of N. We grew seedlings of Amorpha canescens, Dalea purpurea, Lespedeza capitata, and Lupinus perennis at 25/20°C (day/night) or 28/23°C with and without rhizobia and mineral N in controlled-environment growth chambers. Biomass, leaf area, nodule number and mass, and shoot N concentration and δ(15)N values were measured after 12 wk of growth. Both temperature and N-source affected responses in a species-specific manner. Lespedeza showed increased growth and higher shoot N content at 28°C. Lupinus showed decreases in nodulation and lower shoot N concentration at 28°C. The effect of temperature on shoot N concentration occurred only in individuals whose sole N source was N(2)-fixation, but there was no effect of temperature on δ(15)N values in these plants. Elevated temperature enhanced seedling growth of some species, while inhibiting nodulation in another. Temperature-induced shifts in legume composition or nitrogen dynamics may be another potential mechanism through which climate change affects unmanaged ecosystems.

Plant phenology, growth and nutritive quality of Briza maxima: Responses induced by enhanced ozone atmospheric levels and nitrogen enrichment

International Nuclear Information System (INIS)

Sanz, J.; Bermejo, V.; Muntifering, R.; Gonzalez-Fernandez, I.; Gimeno, B.S.; Elvira, S.; Alonso, R.

2011-01-01

An assessment of the effects of tropospheric ozone (O 3 ) levels and substrate nitrogen (N) supplementation, singly and in combination, on phenology, growth and nutritive quality of Briza maxima was carried out. Two serial experiments were developed in Open-Top Chambers (OTC) using three O 3 and three N levels. Increased O 3 exposure did not affect the biomass-related parameters, but enhanced senescence, increased fiber foliar content (especially lignin concentration) and reduced plant life span; these effects were related to senescence acceleration induced by the pollutant. Added N increased plant biomass production and improved nutritive quality by decreasing foliar fiber concentration. Interestingly, the effects of N supplementation depended on meteorological conditions and plant physiological activity. N supplementation counteracted the O 3 -induced senescence but did not modifiy the effects on nutritive quality. Nutritive quality and phenology should be considered in new definitions of the O 3 limits for the protection of herbaceous vegetation. - Research highlights: → Forage quality (foliar protein and fiber content) and phenology are more O 3 -sensitive than growth parameters in the Mediterranean annual grass Briza maxima. → The effects of N supplementation depended on meteorological conditions and plant physiological activity. → Increase in nitrogen supplementation counterbalanced the O 3 -induced increase in senescence biomass. → Nutritive quality and phenology should be considered in new definitions of the O 3 limits for the protection of natural herbaceous vegetation. - Forage quality and phenology are more O 3 -sensitive than growth parameters in the Mediterranean annual grass Briza maxima.

Isotope exchange investigation of nitrogen redistribution in expanded austenite

International Nuclear Information System (INIS)

Christiansen, T.L.; Drouet, M.; Martinavičius, A.; Somers, M.A.J.

2013-01-01

Sequential plasma and gaseous nitriding of Fe–18Cr–10Ni–3Mo stainless steel at 390 °C with 14 N and 15 N isotopes followed by denitriding in flowing hydrogen was investigated. Redistribution of plasma-inserted nitrogen atoms ( 15 N) by subsequent gaseous nitriding ( 14 N) was observed. Denitriding after plasma- and gaseous nitriding resulted in predominant retraction of 14 N, and only a minor amount of 15 N. The nitrogen isotope diffusion behaviour is explained by two different states of nitrogen bonding and short-range ordering between nitrogen and chromium

Effect of Nitrogen Nutritional Stress on Some Growth Parameters of Zea mays L. and Vigna unguiculata (L. Walp.

Directory of Open Access Journals (Sweden)

Akinbode Foluso OLOGUNDUDU

2013-02-01

Full Text Available This study investigated the responses of maize (Zea mays L. and cowpea (Vigna unguiculata L. Walp. seedlings growth parameters to nitrogen nutritional stress. This was with a view to determining whether nitrogen nutritional stress would retard or enhance maize and cowpea growth, partly, wholly or not at all through its effect on biomass accumulation and some morphological parameters. Germination of seeds was done using treated sand in sixty plastic pots. 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 effects of optimal concentration and nitrogen stress on the growth rates (as measured by their fresh and dry weight were studied. The result of the growth analysis showed that there was increase in shoot height with supraoptimal concentrations of nitrogen treatments (X10N and X5N while there was a decrease in shoot height with minus nitrogen (-N regimes. The observed higher biomass (dry matter yield under the FN regimes in both Zea mays and Vigna unguiculata were attributed to optimal nutrient assimilation rate.

Nitrogen Metabolism and Growth Enhancement in Tomato Plants Challenged with Trichoderma harzianum Expressing the Aspergillus nidulans Acetamidase amdS Gene

Science.gov (United States)

Domínguez, Sara; Rubio, M. Belén; Cardoza, Rosa E.; Gutiérrez, Santiago; Nicolás, Carlos; Bettiol, Wagner; Hermosa, Rosa; Monte, Enrique

2016-01-01

Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in Trichoderma harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea, and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by (i) enhanced growth, (ii) increased carbon and nitrogen levels, and (iii) a

Nitrogen metabolism and growth enhancement in tomato plants challenged with Trichoderma harzianum expressing the Aspergillus nidulans acetamidase amdS gene

Directory of Open Access Journals (Sweden)

Sara Domínguez

2016-08-01

Full Text Available Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in T. harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by i enhanced growth, ii increased carbon and nitrogen levels and iii a

Nitrogen Metabolism and Growth Enhancement in Tomato Plants Challenged with Trichoderma harzianum Expressing the Aspergillus nidulans Acetamidase amdS Gene.

Science.gov (United States)

Domínguez, Sara; Rubio, M Belén; Cardoza, Rosa E; Gutiérrez, Santiago; Nicolás, Carlos; Bettiol, Wagner; Hermosa, Rosa; Monte, Enrique

2016-01-01

Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in Trichoderma harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea, and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by (i) enhanced growth, (ii) increased carbon and nitrogen levels, and (iii) a

A bell pepper cultivar tolerant to chilling enhanced nitrogen allocation and stress-related metabolite accumulation in the roots in response to low root-zone temperature.

Science.gov (United States)

Aidoo, Moses Kwame; Sherman, Tal; Lazarovitch, Naftali; Fait, Aaron; Rachmilevitch, Shimon

2017-10-01

Two bell pepper (Capsicum annuum) cultivars, differing in their response to chilling, were exposed to three levels of root-zone temperatures. Gas exchange, shoot and root phenology, and the pattern of change of the central metabolites and secondary metabolites caffeate and benzoate in the leaves and roots were profiled. Low root-zone temperature significantly inhibited gaseous exchange, with a greater effect on the sensitive commercial pepper hybrid (Canon) than on the new hybrid bred to enhance abiotic stress tolerance (S103). The latter was less affected by the treatment with respect to plant height, shoot dry mass, root maximum length, root projected area, number of root tips and root dry mass. More carbon was allocated to the leaves of S103 than nitrogen at 17°C, while in the roots at 17°C, more nitrogen was allocated and the ratio between C/N decreased. Metabolite profiling showed greater increase in the root than in the leaves. Leaf response between the two cultivars differed significantly. The roots accumulated stress-related metabolites including γ-aminobutyric acid (GABA), proline, galactinol and raffinose and at chilling (7°C) resulted in an increase of sugars in both cultivars. Our results suggest that the enhanced tolerance of S103 to root cold stress, reflected in the relative maintenance of shoot and root growth, is likely linked to a more effective regulation of photosynthesis facilitated by the induction of stress-related metabolism. © 2017 Scandinavian Plant Physiology Society.

Enhanced photosynthetic capacity increases nitrogen metabolism through the coordinated regulation of carbon and nitrogen assimilation in Arabidopsis thaliana.

Science.gov (United States)

Otori, Kumi; Tanabe, Noriaki; Maruyama, Toshiki; Sato, Shigeru; Yanagisawa, Shuichi; Tamoi, Masahiro; Shigeoka, Shigeru

2017-09-01

Plant growth and productivity depend on interactions between the metabolism of carbon and nitrogen. The sensing ability of internal carbon and nitrogen metabolites (the C/N balance) enables plants to regulate metabolism and development. In order to investigate the effects of an enhanced photosynthetic capacity on the metabolism of carbon and nitrogen in photosynthetically active tissus (source leaves), we herein generated transgenic Arabidopsis thaliana plants (ApFS) that expressed cyanobacterial fructose-1,6-/sedoheptulose-1,7-bisphosphatase in their chloroplasts. The phenotype of ApFS plants was indistinguishable from that of wild-type plants at the immature stage. However, as plants matured, the growth of ApFS plants was superior to that of wild-type plants. Starch levels were higher in ApFS plants than in wild-type plants at 2 and 5 weeks. Sucrose levels were also higher in ApFS plants than in wild-type plants, but only at 5 weeks. On the other hand, the contents of various free amino acids were lower in ApFS plants than in wild-type plants at 2 weeks, but were similar at 5 weeks. The total C/N ratio was the same in ApFS plants and wild-type plants, whereas nitrite levels increased in parallel with elevations in nitrate reductase activity at 5 weeks in ApFS plants. These results suggest that increases in the contents of photosynthetic intermediates at the early growth stage caused a temporary imbalance in the free-C/free-N ratio and, thus, the feedback inhibition of the expression of genes involved in the Calvin cycle and induction of the expression of those involved in nitrogen metabolism due to supply deficient free amino acids for maintenance of the C/N balance in source leaves of ApFS plants.

A novel enhanced diffusion sampler for collecting gaseous pollutants without air agitation.

Science.gov (United States)

Pan, Xuelian; Zhuo, Shaojie; Zhong, Qirui; Chen, Yuanchen; Du, Wei; Cheng, Hefa; Wang, Xilong; Zeng, Eddy Y; Xing, Baoshan; Tao, Shu

2018-03-06

A novel enhanced diffusion sampler for collecting gaseous phase polycyclic aromatic hydrocarbons (PAHs) without air agitation is proposed. The diffusion of target compounds into a sampling chamber is facilitated by continuously purging through a closed-loop flow to create a large concentration difference between the ambient air and the air in the sampling chamber. A glass-fiber filter-based prototype was developed. It was demonstrated that the device could collect gaseous PAHs at a much higher rate (1.6 ± 1.4 L/min) than regular passive samplers, while the ambient air is not agitated. The prototype was also tested in both the laboratory and field for characterizing the concentration gradients over a short distance from the soil surface. The sampler has potential to be applied in other similar situations to characterize the concentration profiles of other chemicals.

Growth of graphene films from non-gaseous carbon sources

Science.gov (United States)

Tour, James; Sun, Zhengzong; Yan, Zheng; Ruan, Gedeng; Peng, Zhiwei

2015-08-04

In various embodiments, the present disclosure provides methods of forming graphene films by: (1) depositing a non-gaseous carbon source onto a catalyst surface; (2) exposing the non-gaseous carbon source to at least one gas with a flow rate; and (3) initiating the conversion of the non-gaseous carbon source to the graphene film, where the thickness of the graphene film is controllable by the gas flow rate. Additional embodiments of the present disclosure pertain to graphene films made in accordance with the methods of the present disclosure.

Liver changes under the influence of chronic experimental intoxication with nitrogen oxides

Energy Technology Data Exchange (ETDEWEB)

Kosmider, S; Misiewicz, A

1973-01-01

Male guinea pigs were divided into three groups: a control group; a group of animals breathing air containing 1 ppM nitrogen oxides during 6 months, 8 hr/day; and third group exposed to products of reactions between nitrogen oxide and gaseous ammonia. The animals lived through the 6 mo with no increase in mortality. The body weight of the animals exposed to nitrogen oxides increased during the 6 mo by 62 g on the average, while in the control group the body weight increased by 395 g on the average. In homogenates of the livers of the animals exposed to nitrogen oxides, the activities of aldolase, lactic dehydrogenase, acid, and alkaline phosphatase increased, and the activities of cholinesterase, ceruloplasmin, and aminotransferases (aspartic and alanine) decreased. Neutralization of NO/sub x/ by gaseous ammonia restored the disorders in enzyme activities in the liver of the animals exposed to nitrogen oxides to their normal values. The study was statistically analyzed. The livers of the animals exposed to nitrogen oxides contained small foci of necrosis, and hemorrhages could be observed. In some animals, fatty degeneration of the liver could be observed. The changes in the liver can also be associated with inhibited protein synthesis, enhanced catabolic processes, and hypovitaminosis.

Increased nitrogen input enhances Kandelia obovata seedling growth in the presence of invasive Spartina alterniflora in subtropical regions of China.

Science.gov (United States)

Cui, Xiaowei; Song, Weimin; Feng, Jianxiang; Jia, Dai; Guo, Jiemin; Wang, Zhonglei; Wu, Hao; Qi, Fei; Liang, Jie; Lin, Guanghui

2017-01-01

Mangroves in China are severely affected by the rapid invasion of the non-native species Spartina alterniflora Although many studies have addressed the possible impacts of S. alterniflora on the performance of mangrove seedlings, how excessive nitrogen (N) input due to eutrophication affects the interactions between mangrove species and S. alterniflora remains unknown. Here, we report the results from a mesocosm experiment using seedlings of the native mangrove species Kandelia obovata and the exotic S. alterniflora grown in monoculture and mixed culture under no nitrogen addition and nitrogen (N) addition treatments for 18 months. Without N addition, the presence of S. alterniflora inhibited the growth of K. obovata seedlings. Excessive N addition significantly increased the growth rate of K. obovata in both cultures. However, the positive and significantly increasing relative interaction intensity index under excessive N input suggested that the invasion of S. alterniflora could favour the growth of K. obovata under eutrophication conditions. Our results imply that excessive N input in southeastern China can increase the competitive ability of mangrove seedlings against invasive S. alterniflora. © 2017 The Author(s).

Measurements of gaseous multiplication coefficient in pure isobutane

International Nuclear Information System (INIS)

Lima, Iara Batista de

2010-01-01

In this work it is presented measurements of gaseous multiplication coefficient (α) in pure isobutane obtained with a parallel plate chamber, protected against discharges by one electrode (anode) of high resistivity glass (ρ = 2 x 10 12 Ω.cm). The method applied was the Pulsed Townsend, where the primary ionization is produced through the incidence of a nitrogen laser beam onto a metallic electrode (cathode). The electric currents measured with the chamber operating in both ionization and avalanche regimes were used to calculate the gaseous multiplication coefficient by the solution of the Townsend equation for uniform electric fields. The validation of the technique was provided by the measurements of gaseous multiplication coefficient in pure nitrogen, a widely studied gas, which has well-established data in literature. The α coefficients in isobutane were measured as a function of the reduced electric field in the range of 139Td up to 208Td. The obtained values were compared with those simulated by Imonte software (version 4.5) and the only experimental results available in the literature, recently obtained in our group. This comparison showed that the results are concordant within the experimental errors. (author)

Dissolution and Release of Gaseous Nitrogen (N2, N2O) in the Source Region of the Yellow River

Science.gov (United States)

Zhang, L.; Xia, X.; Wang, J.

2017-12-01

Nitrogen is an important biogenic element. The migration and transformation of nitrogen in rivers is an important process affecting global nitrogen cycling and greenhouse gas emissions. However, there is a lack of research on nitrogen removal and greenhouse gas emission characteristics of high altitude rivers. In this work, the spatial and temporal variations of dissolved nitrogen (N2 and N2O) concentrations, saturation, and release flux as well as their responses to environmental factors were studied in the Yellow River source area, a typical high altitude river. The results showed that the dissolved concentrations of N2 and N2O in the rivers were 8.24-137.75 μmol.L-1 and 2.57-31.94 nmol.L-1, respectively. N2 and N2O saturation were greater than 100% for all the sampling sites, indicating that the river is a release source for atmosphere N2 and N2O. Correspondingly, the fluxes of N2 and N2O from river water to atmosphere were 24.12-1606.57 mmol (m2.d) -1 and 12.96-276.81 μmol (m2.d) -1, respectively. Generally, the dissolution concentration and release flux of N2 and N2O in July were larger than that in May. The concentrations of N2 and N2O in river water were related to the environmental factors, and the dissolved concentration of N2 in the surface water was significantly positively correlated with water temperature, NH4+-N and total inorganic nitrogen (DIN) (p<0.01). The dissolved concentration of N2O was significantly positively correlated with the content of suspended particulates, DO, and DIN (p<0.01). Thus, DIN is a key factor in the process of N2 and N2O formation. This study can help to understand the nitrogen cycling in high-altitude rivers and provide basic data for a comprehensive assessment of global river nitrogen loss. Key Words: Source Region of the Yellow River; Gaseous Nitrogen; Nitrogen loss; High altitude river

Sensitivity Analysis of Fatigue Crack Growth Model for API Steels in Gaseous Hydrogen.

Science.gov (United States)

Amaro, Robert L; Rustagi, Neha; Drexler, Elizabeth S; Slifka, Andrew J

2014-01-01

A model to predict fatigue crack growth of API pipeline steels in high pressure gaseous hydrogen has been developed and is presented elsewhere. The model currently has several parameters that must be calibrated for each pipeline steel of interest. This work provides a sensitivity analysis of the model parameters in order to provide (a) insight to the underlying mathematical and mechanistic aspects of the model, and (b) guidance for model calibration of other API steels.

Elementary budget of stag beetle larvae associated with selective utilization of nitrogen in decaying wood

Science.gov (United States)

Tanahashi, Masahiko; Ikeda, Hiroshi; Kubota, Kôhei

2018-06-01

Wood degradation by insects plays important roles for the forest matter cycling. Since wood is deficient in nitrogen compared to the insect body, wood-feeding insects need to assimilate the nitrogen selectively and discard an excess carbon. Such a stoichiometric imbalance between food and body will cause high metabolic cost; therefore, wood-feeding insects may somehow alleviate the stoichiometric imbalance. Here, we investigated the carbon and nitrogen budgets of the larvae of stag beetle, Dorcus rectus, which feed on decaying wood. Assimilation efficiency of ingested wood was 22%, and those values based on the carbon and nitrogen were 27 and 45%, respectively, suggesting the selective digestion of nitrogen in wood. Element-based gross growth efficiency was much higher for nitrogen (45%) than for carbon (3%). As a result, the larvae released 24% of the ingested carbon as volatile, whereas almost no gaseous exchange was observed for nitrogen. Moreover, solubility-based elementary analysis revealed that the larvae mainly utilized alkaline-soluble-water-insoluble fraction of wood, which is rich in nitrogen. Actually, the midgut of the larvae was highly alkaline (pH 10.3). Stag beetle larvae are known to exhibit coprophagy, and here we also confirmed that alkaline-soluble-water-insoluble nitrogen increased again from fresh feces to old feces in the field. Stable isotope analysis suggested the utilization of aerial nitrogen by larvae; however, its actual contribution is still disputable. Those results suggest that D. rectus larvae selectively utilize alkaline-soluble nitrogenous substrates by using their highly alkaline midgut, and perhaps associate with microbes that enhance the nitrogen recycling in feces.

Elementary budget of stag beetle larvae associated with selective utilization of nitrogen in decaying wood.

Science.gov (United States)

Tanahashi, Masahiko; Ikeda, Hiroshi; Kubota, Kôhei

2018-05-03

Wood degradation by insects plays important roles for the forest matter cycling. Since wood is deficient in nitrogen compared to the insect body, wood-feeding insects need to assimilate the nitrogen selectively and discard an excess carbon. Such a stoichiometric imbalance between food and body will cause high metabolic cost; therefore, wood-feeding insects may somehow alleviate the stoichiometric imbalance. Here, we investigated the carbon and nitrogen budgets of the larvae of stag beetle, Dorcus rectus, which feed on decaying wood. Assimilation efficiency of ingested wood was 22%, and those values based on the carbon and nitrogen were 27 and 45%, respectively, suggesting the selective digestion of nitrogen in wood. Element-based gross growth efficiency was much higher for nitrogen (45%) than for carbon (3%). As a result, the larvae released 24% of the ingested carbon as volatile, whereas almost no gaseous exchange was observed for nitrogen. Moreover, solubility-based elementary analysis revealed that the larvae mainly utilized alkaline-soluble-water-insoluble fraction of wood, which is rich in nitrogen. Actually, the midgut of the larvae was highly alkaline (pH 10.3). Stag beetle larvae are known to exhibit coprophagy, and here we also confirmed that alkaline-soluble-water-insoluble nitrogen increased again from fresh feces to old feces in the field. Stable isotope analysis suggested the utilization of aerial nitrogen by larvae; however, its actual contribution is still disputable. Those results suggest that D. rectus larvae selectively utilize alkaline-soluble nitrogenous substrates by using their highly alkaline midgut, and perhaps associate with microbes that enhance the nitrogen recycling in feces.

Electron beam gaseous pollutants treatment

International Nuclear Information System (INIS)

Chmielewski, A.G.

1999-01-01

Emission of gaseous pollutants, mostly during combustion of fossil fuels, creates a threat to the environment. New, economical technologies are needed for flue gas treatment. A physico-chemical basis of the process using electron beam for the simultaneous removal of sulfur and nitrogen oxides and volatile organic compounds are presented in this report. Development of the process and its upscaling has been discussed. (author)

One unit-cell seed layer induced epitaxial growth of heavily nitrogen doped anatase TiO{sub 2} films

Energy Technology Data Exchange (ETDEWEB)

Chen, T L; Hirose, Y; Hitosugi, T; Hasegawa, T [Kanagawa Academy of Science and Technology (KAST), Kawasaki 213-0012 (Japan)], E-mail: chen@ksp.or.jp

2008-03-21

We present a novel way to obtain heavily nitrogen doped anatase TiO{sub 2} films by using a solid-state nitrogen source. Epitaxial growth of the films was realized by introducing one unit-cell seed layer, which was indicated by reflection high-energy electron diffraction as intensity oscillation. Results of x-ray diffraction and x-ray photoelectron spectroscopy confirmed that the films were in the anatase phase heavily doped with nitrogen of {approx}15 at%. The films obtained exhibited considerable narrowing of the optical bandgap, resulting in an enhancement of absorption in the visible-light region. (fast track communication)

Integrated use of plant growth promoting rhizobacteria, biogas slurry and chemical nitrogen for sustainable production of maize under salt-affected conditions

International Nuclear Information System (INIS)

Ahmad, M.; Jamil, M.; Akhtar, F.U.Z.

2014-01-01

Salinity is one of the most critical constraints hampering agricultural production throughout the world, including Pakistan. Some plant growth promoting rhizobacteria (PGPR) have the ability to reduce the deleterious effect of salinity on plants due to the presence of ACC-deaminase enzyme along with some other mechanisms. The integrated use of organic, chemical and biofertilizers can reduce dependence on expensive chemical inputs. To sustain high crop yields without deterioration of soil fertility, it is important to work out optimal combination of chemical and biofertilizers, and manures in the cropping system. A pot trial was conducted to study the effect of integrated use of PGPR, chemical nitrogen, and biogas slurry for sustainable production of maize under salt-stressed conditions and for good soil health. Results showed that sole application of PGPR, chemical nitrogen and biogas slurry enhanced maize growth but their combined application was more effective. Maximum improvement in maize growth, yield, ionic concentration in leaves and nutrient concentration in grains was observed in the treatment where PGPR and biogas slurry was used in the presence of 100% recommended nitrogen as chemical fertilizer. It also improved the soil pH, ECe, and available N, P and K contents. It is concluded that integrated use of PGPR, biogas slurry and chemical nitrogen not only enhanced maize growth, yield and quality but also improved soil health. So, it may be evaluated under field conditions to get sustained yield of maize from salt-affected soils. (author)

Real-time observation of epitaxial crystal growth in gaseous environment using x-ray diffraction and x-ray reflectometry

International Nuclear Information System (INIS)

Kawamura, Tomoaki; Bhunia, Satyaban; Watanabe, Yoshio; Fujikawa, Seiji

2008-01-01

We made the x-ray diffractometer combined with the MOCVD growth system for the real-time observation of epitaxial growth in gaseous environment, and investigated the growth mechanism of InP crystals. Changes of the (-5/2 O) Bragg diffraction during the growth revealed that the growth starts immediately after the In source has been supplied and gradually stopped, owing to the migrating In atoms on the surface. Additionally, one can easily determine the growth modes, including 3-dimensional mode, layer-by-layer mode, and step-flow mode, by observing the change of x-ray reflectivity with various growth conditions. (author)

Enhanced cytocompatibility of silver-containing biointerface by constructing nitrogen functionalities

Energy Technology Data Exchange (ETDEWEB)

Zhang, Wei, E-mail: weizhang@mail.ipc.ac.cn [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Jun [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Wang, Huaiyu [Department of Physics & Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Xu, Ying; Wang, Pingli [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Ji, Junhui, E-mail: jhji@mail.ipc.ac.cn [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Chu, Paul K. [Department of Physics & Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

2015-09-15

Graphical abstract: Constructing nitrogen functionalities is promising method to enhance cytocompatibility of the biointerface by simultaneous Ag and N{sub 2} plasma modification. - Highlights: • N{sub 2} plasma immersion ion implantation (PIII) treatment generates plenty of nitrogen functionalities on polymer substrate. • N{sub 2} PIII treatment increases surface roughness and hydrophilicity and improves its capability to adsorb protein. • Simultaneous Ag and N{sub 2} plasma modification constructs nitrogen functionalities to enhance cytocompatibility of the biointerface. - Abstract: Silver (Ag) has recently been introduced into polymeric biomedical implants by plasma immersion ion implantation (PIII) to enhance the antibacterial capability. However, Ag ions and nanoparticles can increase the cytotoxicity and inhibit cellular proliferation and the relationship is time- and dose-dependent. In this study, Ag and N{sub 2} PIII is conducted in concert to produce nitrogen functional groups as well as Ag-containing biointerface. In addition to the creation of nitrogen functionalities, the surface roughness and hydrophilicity are improved in favor of protein adsorption. Compared to the biointerface created by Ag PIII only, the nitrogen functionalities generated by N{sub 2} co-PIII do not affect DNA synthesis and the total protein level but evidently enhance cellular adhesion, viability, and proliferation at the biointerface. The modified surface is observed to upregulate the osteogenesis-related marker expression of bone cells in contact. Our findings suggest that dual Ag and N{sub 2} PIII is a desirable technique to enhance both the cytocompatibility and antibacterial capability of medical polymers.

Influence of carbohydrate addition on nitrogen transformations and greenhouse gas emissions of intensive aquaculture system.

Science.gov (United States)

Hu, Zhen; Lee, Jae Woo; Chandran, Kartik; Kim, Sungpyo; Sharma, Keshab; Khanal, Samir Kumar

2014-02-01

Aquaculture is one of the fastest-growing segments of the food economy in modern times. It is also being considered as an important source of greenhouse gas (GHG) emissions. To date, limited studies have been conducted on GHG emissions from aquaculture system. In this study, daily addition of fish feed and soluble starch at a carbon-to-nitrogen (C/N) ratio of 16:1 (w/w) was used to examine the effects of carbohydrate addition on nitrogen transformations and GHG emissions in a zero-water exchange intensive aquaculture system. The addition of soluble starch stimulated heterotrophic bacterial growth and denitrification, which led to lower total ammonia nitrogen, nitrite and nitrate concentrations in aqueous phase. About 76.2% of the nitrogen output was emitted in the form of gaseous nitrogen (i.e., N2 and N2O) in the treatment tank (i.e., aquaculture tank with soluble starch addition), while gaseous nitrogen accounted for 33.3% of the nitrogen output in the control tank (i.e., aquaculture tank without soluble starch addition). Although soluble starch addition reduced daily N2O emissions by 83.4%, it resulted in an increase of daily carbon dioxide (CO2) emissions by 91.1%. Overall, starch addition did not contribute to controlling the GHG emissions from the aquaculture system. © 2013.

An example of transition from a corrosion process in gaseous phase to corrosion in aqueous environment: the case of Z2CN18-10 stainless steel by iodine and water in vapour phase

International Nuclear Information System (INIS)

Mathieu, Bruno

1990-01-01

This research thesis addresses an example of transition of a corrosion process in gaseous phase towards corrosion in aqueous environment, specifically in the case of the corrosion of the Z2CN18-10 stainless steel by gaseous iodine in presence of water vapour (and possibly nitrogen dioxide). This transition occurs in two steps: initiation in gaseous phase and growth in aqueous environment. This transition is due to hygroscopic properties of mostly chromium iodides and, to a lesser extent, iron iodides. Morphological, electrochemical and thermogravimetry studies have been performed by varying different parameters governing corrosion processes: corrosion temperature, iodine concentration, relative humidity, and reaction time [fr

Effects of elevated carbon dioxide concentration on growth and nitrogen fixation in Alnus glutinosa in a long-term field experiment

Energy Technology Data Exchange (ETDEWEB)

Temperton, V. M.; Jackson, G.; Barton, C. V. M.; Jarvis, P. G. [Edinburgh Univ., Inst. of Ecology and Resource Management, Edinburgh (United Kingdom); Grayston, S. J. [Macaulay Land Use Research Inst., Plant-Soil Interaction Group, Aberdeen (United Kingdom)

2003-10-01

Total biomass, relative growth rate, net assimilation rate, leaf area and net photosynthetic rate of nitrogen-fixing were measured in common alder trees, grown for three years in open-top chambers in the presence of either ambient or elevated atmospheric carbon dioxide, and in two soil nitrogen regimes: i.e. full nutrient solution or no fertilizer. The objective was to clarify the relationship between elevated carbon dioxide and the rate of nitrogen fixation of nodulated trees growing under field conditions. Results showed that growth in elevated carbon dioxide stimulated net photosynthesis and total biomass accumulation. However, relative growth rate was not significantly affected by elevated carbon dioxide. Leaf area and leaf phosphorus concentration were also unaffected. Nodule mass on roots of unfertilized trees exposed to elevated carbon dioxide increased, compared with fertilized trees exposed to ambient carbon dioxide levels. Since neither in the fertilized, nor the unfertilized trees was there any evidence of effects on growth, biomass and photosynthesis that could be attributed to the interaction of fertilizer and elevated carbon dioxide interaction, it was concluded that both types exhibit similar carbon dioxide-induced growth and photosynthetic enhancements. 40 refs., 5 tabs., 3 figs.

Effects of elevated carbon dioxide concentration on growth and nitrogen fixation in Alnus glutinosa in a long-term field experiment

International Nuclear Information System (INIS)

Temperton, V. M.; Jackson, G.; Barton, C. V. M.; Jarvis, P. G.; Grayston, S. J.

2003-01-01

Total biomass, relative growth rate, net assimilation rate, leaf area and net photosynthetic rate of nitrogen-fixing were measured in common alder trees, grown for three years in open-top chambers in the presence of either ambient or elevated atmospheric carbon dioxide, and in two soil nitrogen regimes: i.e. full nutrient solution or no fertilizer. The objective was to clarify the relationship between elevated carbon dioxide and the rate of nitrogen fixation of nodulated trees growing under field conditions. Results showed that growth in elevated carbon dioxide stimulated net photosynthesis and total biomass accumulation. However, relative growth rate was not significantly affected by elevated carbon dioxide. Leaf area and leaf phosphorus concentration were also unaffected. Nodule mass on roots of unfertilized trees exposed to elevated carbon dioxide increased, compared with fertilized trees exposed to ambient carbon dioxide levels. Since neither in the fertilized, nor the unfertilized trees was there any evidence of effects on growth, biomass and photosynthesis that could be attributed to the interaction of fertilizer and elevated carbon dioxide interaction, it was concluded that both types exhibit similar carbon dioxide-induced growth and photosynthetic enhancements. 40 refs., 5 tabs., 3 figs

Ultraviolet-B radiation and nitrogen effects on growth and yield of maize under Mediterranean field conditions

OpenAIRE

Correia, Carlos M.; Coutinho, João F.; Björn, Lars Olof; Torres-Pereira, José M. G.

2000-01-01

The effects of an increase in UV-B radiation on growth and yield of maize (Zea mays L.) were investigated at four levels of applied nitrogen (0, 100, 200 and 300 kg ha−1 of N) under Mediterranean field conditions. The experiment simulated a 20% stratospheric ozone depletion over Portugal. Enhanced UV-B and N deficiency decreased yield and total biomass production by 22–49%. High UV-B dose reduced yield, total biomass and growth of N-fertilized maize plants but did not affect N-stressed plants...

Effects of Organic and Inorganic Nitrogen on the Growth and Production of Domoic Acid by Pseudo-nitzschia multiseries and P. australis (Bacillariophyceae) in Culture.

Science.gov (United States)

Martin-Jézéquel, Véronique; Calu, Guillaume; Candela, Leo; Amzil, Zouher; Jauffrais, Thierry; Séchet, Véronique; Weigel, Pierre

2015-11-26

Over the last century, human activities have altered the global nitrogen cycle, and anthropogenic inputs of both inorganic and organic nitrogen species have increased around the world, causing significant changes to the functioning of aquatic ecosystems. The increasing frequency of Pseudo-nitzschia spp. in estuarine and coastal waters reinforces the need to understand better the environmental control of its growth and domoic acid (DA) production. Here, we document Pseudo-nitzschia spp. growth and toxicity on a large set of inorganic and organic nitrogen (nitrate, ammonium, urea, glutamate, glutamine, arginine and taurine). Our study focused on two species isolated from European coastal waters: P. multiseries CCL70 and P. australis PNC1. The nitrogen sources induced broad differences between the two species with respect to growth rate, biomass and cellular DA, but no specific variation could be attributed to any of the inorganic or organic nitrogen substrates. Enrichment with ammonium resulted in an enhanced growth rate and cell yield, whereas glutamate did not support the growth of P. multiseries. Arginine, glutamine and taurine enabled good growth of P. australis, but without toxin production. The highest DA content was produced when P. multiseries grew with urea and P. australis grew with glutamate. For both species, growth rate was not correlated with DA content but more toxin was produced when the nitrogen source could not sustain a high biomass. A significant negative correlation was found between cell biomass and DA content in P. australis. This study shows that Pseudo-nitzschia can readily utilize organic nitrogen in the form of amino acids, and confirms that both inorganic and organic nitrogen affect growth and DA production. Our results contribute to our understanding of the ecophysiology of Pseudo-nitzschia spp. and may help to predict toxic events in the natural environment.

Study of various NH4+/NO3- mixtures for enhancing growth of potatoes

Science.gov (United States)

Cao, W.; Tibbitts, T. W.

1993-01-01

Two experiments were conducted to determine the effects of various NH4(+)-N/NO3(-)-N percentages on growth and mineral concentrations in potato (Solanum tuberosum L.) plants using a non-recirculating nutrient film system in a controlled environment. The first experiment included six NH4(+)-N/NO3(-)-N percentages at 0/100, 20/80, 40/60, 60/40, 80/20, and 100/0 with the same total N concentration of 4 mM. The second experiment included six NH4(+)-N/NO3(-)-N percentages at 0/100, 4/96, 8/92, 12/88, 16/84, and 20/80 again with the same total N of 4 mM. In each experiment, plants were harvested 35 days after transplanting when tubers had been initiated and started to enlarge. Dry weights of shoots, tubers, and whole plant at the harvest were increased significantly with all mixed nitrogen treatments as compared with single NH4+ or NO3- form. The enhanced growth with mixed nitrogen was greatest at 8% to 20% NH4(+)-N. Also, the concentrations and accumulation of total N in the shoots and roots were greater with mixed nitrogen than with separate NH4+ or NO3- nutrition. With NH4+ present in the solutions, the concentrations of P and Cl in the shoots were increased compared to NO3- alone, whereas the tissue concentrations of Ca and Mg were decreased. It was concluded that nitrogen fertilization provided with combined NH4+ and NO3- forms, even at small proportions of NH4+, can enhance nitrogen uptake and productivity in potato plants.

Trichoderma asperellum T42 Reprograms Tobacco for Enhanced Nitrogen Utilization Efficiency and Plant Growth When Fed with N Nutrients

Directory of Open Access Journals (Sweden)

Bansh N. Singh

2018-02-01

Full Text Available Trichoderma spp., are saprophytic fungi that can improve plant growth through increased nutrient acquisition and change in the root architecture. In the present study, we demonstrate that Trichoderma asperellum T42 mediate enhancement in host biomass, total nitrogen content, nitric oxide (NO production and cytosolic Ca2+ accumulation in tobacco. T42 inoculation enhanced lateral root, root hair length, root hair density and root/shoot dry mass in tobacco under deprived nutrients condition. Interestingly, these growth attributes were further elevated in presence of T42 and supplementation of NO3- and NH4+ nutrients to tobacco at 40 and 70 days, particularly in NO3- supplementation, whereas no significant increment was observed in nia30 mutant. In addition, NO production was more in tobacco roots in T42 inoculated plants fed with NO3- nutrient confirming NO generation was dependent on NR pathway. NO3- dependent NO production contributed to increase in lateral root initiation, Ca2+ accumulation and activities of nitrate transporters (NRTs in tobacco. Higher activities of several NRT genes in response to T42 and N nutrients and suppression of ammonium transporter (AMT1 suggested that induction of high affinity NRTs help NO3- acquisition through roots of tobacco. Among the NRTs NRT2.1 and NRT2.2 were more up-regulated compared to the other NRTs. Addition of sodium nitroprusside (SNP, relative to those supplied with NO3-/NH4+ nutrition and T42 treated plants singly, and with application of NO inhibitor, cPTIO, confirmed the altered NO fluorescence intensity in tobacco roots. Our findings suggest that T42 promoted plant growth significantly ant N content in the tobacco plants grown under N nutrients, notably higher in NO3-, providing insight of the strategy for not only tobacco but probably for other crops as well to adapt to fluctuating nitrate availability in soil.

Impact of nitrogen nutrition and moisture deficits on growth, yield ...

African Journals Online (AJOL)

In order to evaluate the impact of nitrogen nutrition and moisture deficits on growth, yield and radiation use efficiency of wheat (Triticum aestivum L.), a field experiment was conducted at Agronomic Research Area, University of Agriculture Faisalabad, during 2008 to 2009. The study comprised of four nitrogen levels, that is, ...

Enhanced vegetation growth peak and its key mechanisms

Science.gov (United States)

Huang, K.; Xia, J.; Wang, Y.; Ahlström, A.; Schwalm, C.; Huntzinger, D. N.; Chen, J.; Cook, R. B.; Fang, Y.; Fisher, J. B.; Jacobson, A. R.; Michalak, A.; Schaefer, K. M.; Wei, Y.; Yan, L.; Luo, Y.

2017-12-01

It remains unclear that whether and how the vegetation growth peak has been shifted globally during the past three decades. Here we used two global datasets of gross primary productivity (GPP) and a satellite-derived Normalized Difference Vegetation Index (NDVI) to characterize recent changes in seasonal peak vegetation growth. The attribution of changes in peak growth to their driving factors was examined with several datasets. We demonstrated that the growth peak of global vegetation has been linearly increasing during the past three decades. About 65% of this trend is evenly explained by the expanding croplands (21%), rising atmospheric [CO2] (22%), and intensifying nitrogen deposition (22%). The contribution of expanding croplands to the peak growth trend was substantiated by measurements from eddy-flux towers, sun-induced chlorophyll fluorescence and a global database of plant traits, all of which demonstrated that croplands have a higher photosynthetic capacity than other vegetation types. The contribution of rising atmospheric [CO2] and nitrogen deposition are consistent with the positive response of leaf growth to elevated [CO2] (25%) and nitrogen addition (8%) from 346 manipulated experiments. The positive effect of rising atmospheric [CO2] was also well captured by 15 terrestrial biosphere models. However, most models underestimated the contributions of land-cover change and nitrogen deposition, but overestimated the positive effect of climate change.

Increased iron availability resulting from increased CO2 enhances carbon and nitrogen metabolism in the economical marine red macroalga Pyropia haitanensis (Rhodophyta).

Science.gov (United States)

Chen, Binbin; Zou, Dinghui; Yang, Yufeng

2017-04-01

Ocean acidification caused by rising CO 2 is predicted to increase the concentrations of dissolved species of Fe(II) and Fe(III), leading to the enhanced photosynthetic carbon sequestration in some algal species. In this study, the carbon and nitrogen metabolism in responses to increased iron availability under two CO 2 levels (390 μL L -1 and 1000 μL L -1 ), were investigated in the maricultivated macroalga Pyropia haitanensis (Rhodophyta). The results showed that, elevated CO 2 increased soluble carbonhydrate (SC) contents, resulting from enhanced photosynthesis and photosynthetic pigment synthesis in this algae, but declined its soluble protein (SP) contents, resulting in increased ratio of SC/SP. This enhanced photosynthesis performance and carbon accumulation was more significant under iron enrichment condition in seawater, with higher iron uptake rate at high CO 2 level. As a key essential biogenic element for algae, Fe-replete functionally contributed to P. haitanensis photosynthesis. Increased SC fundamentally provided carbon skeletons for nitrogen assimilation. The significant increase of carbon and nitrogen assimilation finally contributed to enhanced growth in this alga. This was also intuitively reflected by respiration that provided energy for cellular metabolism and algal growth. We propose that, in the predicted scenario of rising atmospheric CO 2 , P. haitanensis is capable to adjust its physiology by increasing its carbon and nitrogen metabolism to acclimate the acidified seawater, at the background of global climate change and simultaneously increased iron concentration due to decreased pH levels. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enhancement of cell growth on honeycomb-structured polylactide surface using atmospheric-pressure plasma jet modification

Energy Technology Data Exchange (ETDEWEB)

Cheng, Kuang-Yao; Chang, Chia-Hsing; Yang, Yi-Wei; Liao, Guo-Chun; Liu, Chih-Tung; Wu, Jong-Shinn, E-mail: chongsin@faculty.nctu.edu.tw

2017-02-01

Graphical abstract: Atmospheric-pressure plasma enhances cell growth on two different pore sizes of honeycomb pattern on polylactide surface. - Highlights: • Different pore sizes of honeycomb pattern on PLA film are created. • The two-step plasma treatment provided the oxygen- and nitrogen-containing functional groups that had a major impact on cell cultivation. • The plasma treatment had a significant effect for cell proliferation. • The surface structures are the main influence on cell cultivation, while plasma treatment can indeed improve the growth environment. - Abstract: In this paper, we compare the cell growth results of NIH-3T3 and Neuro-2A cells over 72 h on flat and honeycomb structured PLA films without and with a two-step atmospheric-pressure nitrogen-based plasma jet treatment. We developed a fabrication system used for forming of a uniform honeycomb structure on PLA surface, which can produce two different pore sizes, 3–4 μm and 7–8 μm, of honeycomb pattern. We applied a previously developed nitrogen-based atmospheric-pressure dielectric barrier discharge (DBD) jet system to treat the PLA film without and with honeycomb structure. NIH-3T3 and a much smaller Neuro-2A cells were cultivated on the films under various surface conditions. The results show that the two-step plasma treatment in combination with a honeycomb structure can enhance cell growth on PLA film, should the cell size be not too smaller than the pore size of honeycomb structure, e.g., NIH-3T3. Otherwise, cell growth would be better on flat PLA film, e.g., Neuro-2A.

Growth and nitrogen dynamics of glycine max inoculated with bradyrhizobium japonicum and exposed to elevated atmospheric carbon dioxide

International Nuclear Information System (INIS)

Rehman, A.; Hamid, N.; Jawaid, F.

2010-01-01

Seeds of Glycine max (soybean) were inoculated with N-fixing bacterium Bradyrhizobium japonicum and grown in growth chamber to investigate interactive effects of atmospheric CO/sub 2/ and plants Nitrogen status on root and shoot length and biomass, nodule formation and Nitrogen concentration. Plants were grown with CO/sub 2/ at 3500 and 1000 ppm with or without Bradyrhizobium japonicum inoculation. Root and shoot length and dry mass of Glycine max increased significantly with CO/sub 2/ enrichment provided with Bradyrhizobium japonicum as compared to deficient Nitrogen fixing bacterium. While ambient and enriched CO/sub 2/ levels resulted in increased Nitrogen concentration of Glycine max shoot and root which is inoculated with N-fixing bacterium. Nodule formation was also enhanced in plants supplied with Bradyrhizobium japonicum as compared to plants which is Bradyrhizobium japonicum deficient at both CO/sub 2/ concentrations. (author)

Nitrogen deficiency inhibits leaf blade growth in Lolium perenne by increasing cell cycle duration and decreasing mitotic and post-mitotic growth rates.

Science.gov (United States)

Kavanová, Monika; Lattanzi, Fernando Alfredo; Schnyder, Hans

2008-06-01

Nitrogen deficiency severely inhibits leaf growth. This response was analysed at the cellular level by growing Lolium perenne L. under 7.5 mM (high) or 1 mM (low) nitrate supply, and performing a kinematic analysis to assess the effect of nitrogen status on cell proliferation and cell growth in the leaf blade epidermis. Low nitrogen supply reduced leaf elongation rate (LER) by 43% through a similar decrease in the cell production rate and final cell length. The former was entirely because of a decreased average cell division rate (0.023 versus 0.032 h(-1)) and thus longer cell cycle duration (30 versus 22 h). Nitrogen status did not affect the number of division cycles of the initial cell's progeny (5.7), and accordingly the meristematic cell number (53). Meristematic cell length was unaffected by nitrogen deficiency, implying that the division and mitotic growth rates were equally impaired. The shorter mature cell length arose from a considerably reduced post-mitotic growth rate (0.033 versus 0.049 h(-1)). But, nitrogen stress did not affect the position where elongation stopped, and increased cell elongation duration. In conclusion, nitrogen deficiency limited leaf growth by increasing the cell cycle duration and decreasing mitotic and post-mitotic elongation rates, delaying cell maturation.

Growth of nitrogen-doped graphene on copper: Multiscale simulations

Science.gov (United States)

Gaillard, P.; Schoenhalz, A. L.; Moskovkin, P.; Lucas, S.; Henrard, L.

2016-02-01

We used multiscale simulations to model the growth of nitrogen-doped graphene on a copper substrate by chemical vapour deposition (CVD). Our simulations are based on ab-initio calculations of energy barriers for surface diffusion, which are complemented by larger scale Kinetic Monte Carlo (KMC) simulations. Our results indicate that the shape of grown doped graphene flakes depends on the temperature and deposition flux they are submitted during the process, but we found no significant effect of nitrogen doping on this shape. However, we show that nitrogen atoms have a preference for pyridine-like sites compared to graphite-like sites, as observed experimentally.

The influence of different forms and concentrations of nitrogen on ...

African Journals Online (AJOL)

... mass and leaf area development were enhanced in plants supplied with nitrogen in any form. It was suggested that growth of D. eriantha was influenced by carbohydrate fluctuations.D. eriantha. Keywords: botany; carbohydrates; digitaria eriantha; dry mass; growth; leaf area; leaves; nitrogen; physiology; plant physiology; ...

Foliar application of pyraclostrobin fungicide enhances the growth, rhizobial-nodule formation and nitrogenase activity in soybean (var. JS-335).

Science.gov (United States)

Joshi, Juhie; Sharma, Sonika; Guruprasad, K N

2014-09-01

A field study was conducted to investigate the impact of the fungicide pyraclostrobin (F500 - Headline®; a.i. 20%) on the activity of nitrogenase in soybean (var. JS-335). Pyraclostrobin (F500) was applied on the leaves of soybean plants at 10 and 20 days after emergence (DAE) of seedlings at concentrations ranging from 0.05% to 1%. Leghemoglobin (Lb) content and nitrogenase activity in root nodules were analyzed at 45(th)day after emergence of seedlings indicated a remarkable increase in Lb content and enhanced activity of nitrogenase in the root nodules of pyraclostrobin treated plants. The fungicide also enhanced the number of nodules along with weight of nodules, root biomass and growth of shoot and leaves. Enhanced nitrogen fixation in the root nodules by pyraclostrobin improves the growth of the plant in soybean before flowering and pod formation which ultimately resulted in yield and yield attributes. These results suggest that pyraclostrobin (F500) can be successfully employed as a foliar spray under field conditions to enhance the growth, nitrogen assimilation and hence yield of soybean. Copyright © 2014 Elsevier Inc. All rights reserved.

Studies on the injuries of crops by harmful gases under covering. I. Injuries of vegetables by gaseous nitrogen dioxide and the conditions affecting crop susceptibility. [Eggplant

Energy Technology Data Exchange (ETDEWEB)

Kato, T; Tachibana, S; Inden, T

1974-09-01

The effects of environmental conditions such as soil-moisture humidity, and light on injuries to crops such as kidney bean, cucumber, tomato, and egg plant as well as the relationships between injury occurrence and plant nutrition, age of seedlings, and leaf position were investigated when the crops were exposed to gaseous nitrogen dioxide under a covering. The injury was severer when the soil moisture was richer and the humidity was higher. Injury was greater under dark conditions as opposed to light conditions before, during, and after NO/sub 2/ exposure. The first leaves of kidney bean plants were more susceptible to the gas when they were younger. Leaves with active metabolism (in the middle position) were the most susceptible to NO/sub 2/. Vegetables grown in fields or cultures poor in nitrogen were apparently susceptible to the gas, and those grown in ammonia-nitrogen rich cultures were more severely injured than those grown on nitrate-nitrogen rich cultures. Those grown in iron-deficient cultures were more susceptible to NO/sub 2/ than controls.

Fate of fertilizer nitrogen in soil-plant system under irrigating condition. Pt.1: Effect of nitrogen level

International Nuclear Information System (INIS)

Chen Qing; Wen Xianfang; Zheng Xingyun; Pan Jiarong

1997-01-01

Three nitrogen fertilization levels including optimum rate of nitrogen applied (N1.0, 150 kg N·ha -1 ), 150% of optimum rate (N1.5, 225 kg N·ha -1 ) and 50% of optimum rate (N0.5, 75 kg N·ha -1 ) were selected to determine the fate of nitrogen in soil plant system by 15 N technique in 1994∼1995 field experiment which was conducted in Shijiazhuang. The results showed that under irrigated condition the nitrogen use efficiencies (NUE) of ammonium bicarbonate by winter wheat in fertilized treatments were 38.5%, 32.3% and 22.4% respectively, while the highest NUE of winter wheat was found in N0.5 treatment due to a relatively high fertility. The highest yield (6.8 x 10 3 kg grain·ha -1 , 14.7 x 10 3 kg top·ha -1 ) was obtained in N1.0 treatment, but nitrogen uptake and grain yield in N1.5 treatment were lower than those of other fertilizer treatments and there was no significant difference between N0.0 and N1.5 in grain yield. the highest residue of fertilizer N was determined in N1.5 treatment, of which 46% existed in the top layer of the soil (0∼50 cm). There was no significant difference in residual fertilizer N in soil between the other two treatments (31.28% in N0.5, 31.12% in N1.0). In 15 N balance calculation, the unaccounted part of applied N which was leaching down 50 cm in the soil profile as nitrate or gaseous loss through volatilization, denitrification were 30.20%, the soil profile as nitrate or gaseous loss through volatilization, denitrification were 30.20%, 36.56%, 31.25% in N0.5, N1.5 treatments, respectively. It is very important to control residual N in order to prevent N pollution and promote the growth of next crop

Growth and foliar nitrogen concentrations of interplanted native woody legumes and pecan

Science.gov (United States)

J.W. Van Sambeek; Nadia E. Navarrete-Tindall; Kenneth L. Hunt

2008-01-01

The interplanting and underplanting of nodulated nitrogen-fixing plants in tree plantings can increase early growth and foliage nitrogen content of hardwoods, especially black walnut and pecan. Recent studies have demonstrated that some non-nodulated woody legumes may be capable of fixing significant levels of atmospheric nitrogen. The following nine nurse crop...

Loss of nitrogen (study with 15N) as gaseous oxides under submerged conditions of paddy

International Nuclear Information System (INIS)

Mandal, S.R.; Datta, N.P.

1987-01-01

The experiment in a specially designed, air-tight pot with rice and different water soluble grades of nitrophosphate, ammonium nitrate (plus super phosphate) tagged with six atom per cent excess 15 N clearly revealed that the loss of nitrogen as oxides during the growth period of rice under submerged condition was very small (1.48 to 2.57 mg/pot). The 15 N content in the lost oxides was also very small and a small traction of total nitrogen applied represented the loss in this channel (0.0062 to 0.0163 per cent). The loss was influenced by NH 4 :NO 3 ratio in the fertilizer and increased with the increasing quantity of nitrate present in the fertilizers. (author)

Enhancement of L-phenylalanine production by engineered Escherichia coli using phased exponential L-tyrosine feeding combined with nitrogen source optimization.

Science.gov (United States)

Yuan, Peipei; Cao, Weijia; Wang, Zhen; Chen, Kequan; Li, Yan; Ouyang, Pingkai

2015-07-01

Nitrogen source optimization combined with phased exponential L-tyrosine feeding was employed to enhance L-phenylalanine production by a tyrosine-auxotroph strain, Escherichia coli YP1617. The absence of (NH4)2SO4, the use of corn steep powder and yeast extract as composite organic nitrogen source were more suitable for cell growth and L-phenylalanine production. Moreover, the optimal initial L-tyrosine level was 0.3 g L(-1) and exponential L-tyrosine feeding slightly improved L-phenylalanine production. Nerveless, L-phenylalanine production was greatly enhanced by a strategy of phased exponential L-tyrosine feeding, where exponential feeding was started at the set specific growth rate of 0.08, 0.05, and 0.02 h(-1) after 12, 32, and 52 h, respectively. Compared with exponential L-tyrosine feeding at the set specific growth rate of 0.08 h(-1), the developed strategy obtained a 15.33% increase in L-phenylalanine production (L-phenylalanine of 56.20 g L(-1)) and a 45.28% decrease in L-tyrosine supplementation. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Studies on the injuries of crops by harmful gases under covering. II. On the mechanism of crop injury due to gaseous nitrogen dioxide. [Eggplant

Energy Technology Data Exchange (ETDEWEB)

Kato, T; Tachibana, S; Inden, T

1974-12-01

The mechanism of crop injury by nitrogen dioxide gas was investigated by exploring kidney bean, cucumber, tomato, egg plant, and spinach plants 6.0 to 17 ppM NO/sub 2/ under various conditions. The application of aqueous oxyethylene decasanol on crop leaves reduced the injury due to the gas, expecially on the lower leaf sides. Leaves exposed to NO/sub 2/ in the dark showed severer injury and contained more nitrite anion than those exposed to NO/sub 2/ in the light. Leaves smeared with an aqueous sodium nitrite solution showed the same type of injury as that induced by NO/sub 2/. After treatment with 3-(3,4-dichlorophenyl)-1,1- dimethylurea, the leaves became more susceptible to the gas even under light and formed more nitrite anion than controls. Plants grown in nitrate-nitrogen cultures were less susceptible to NO/sub 2/ damage than those grown in ammonia-nitrogen cultures or cultures without nitrogen and contained less nitrite anion than others. Plant injury by gaseous nitrogen dioxide appeared to be caused by nitrite anion. Susceptibility to NO/sub 2/ depended on the amount of the gas taken in by stomata and on the physiological activity of the plant which reduces the anion. The reduction is carried out by nitrite reductase. The photochemical reduction by reductase in chloroplasts appears to be related to the injury-reducing effect of light.

Growth of Rhodococcus sp. strain BCP1 on gaseous n-alkanes: new metabolic insights and transcriptional analysis of two soluble di-iron monooxygenase genes

Science.gov (United States)

Cappelletti, Martina; Presentato, Alessandro; Milazzo, Giorgio; Turner, Raymond J.; Fedi, Stefano; Frascari, Dario; Zannoni, Davide

2015-01-01

Rhodococcus sp. strain BCP1 was initially isolated for its ability to grow on gaseous n-alkanes, which act as inducers for the co-metabolic degradation of low-chlorinated compounds. Here, both molecular and metabolic features of BCP1 cells grown on gaseous and short-chain n-alkanes (up to n-heptane) were examined in detail. We show that propane metabolism generated terminal and sub-terminal oxidation products such as 1- and 2-propanol, whereas 1-butanol was the only terminal oxidation product detected from n-butane metabolism. Two gene clusters, prmABCD and smoABCD—coding for Soluble Di-Iron Monooxgenases (SDIMOs) involved in gaseous n-alkanes oxidation—were detected in the BCP1 genome. By means of Reverse Transcriptase-quantitative PCR (RT-qPCR) analysis, a set of substrates inducing the expression of the sdimo genes in BCP1 were assessed as well as their transcriptional repression in the presence of sugars, organic acids, or during the cell growth on rich medium (Luria–Bertani broth). The transcriptional start sites of both the sdimo gene clusters were identified by means of primer extension experiments. Finally, proteomic studies revealed changes in the protein pattern induced by growth on gaseous- (n-butane) and/or liquid (n-hexane) short-chain n-alkanes as compared to growth on succinate. Among the differently expressed protein spots, two chaperonins and an isocytrate lyase were identified along with oxidoreductases involved in oxidation reactions downstream of the initial monooxygenase reaction step. PMID:26029173

Nitrogen nutrition and temporal effects of enhanced carbon dioxide on soybean growth

Science.gov (United States)

Vessey, J. K.; Henry, L. T.; Raper, C. D. Jr

1990-01-01

Plants grown on porous media at elevated CO2 levels generally have low concentrations of tissue N and often appear to require increased levels of external N to maximize growth response. This study determines if soybean [Glycine max (L.) Merr. Ransom'] grown hydroponically at elevated CO2 requires increases in external NO3- concentrations beyond levels that are optimal at ambient CO2 to maintain tissue N concentrations and maximize the growth response. This study also investigates temporal influences of elevated CO2 on growth responses by soybean. Plants were grown vegetatively for 34 d in hydroponic culture at atmospheric CO2 concentrations of 400, 650, and 900 microliters L-1 and during the final 18 d at NO3- concentrations of 0.5, 1.0, 5.0 and 10.0 mM in the culture solution. At 650 and 900 microliters L-1 CO2, plants had maximum increases of 31 and 45% in dry weight during the experimental period. Plant growth at 900 microliters L-1 CO2 was stimulated earlier than at 650 microliters L-1. During the final 18 d of the experiment, the relative growth rates (RGR) of plants grown at elevated CO2 declined. Elevated CO2 caused increases in total N and total NO3(-)-N content and leaf area but not leaf number. Enhancing CO2 levels also caused a decrease in root:shoot ratios. Stomatal resistance increased by 2.1- and 2.8-fold for plants at the 650 and 900 microliters L-1 CO2, respectively. Nitrate level in the culture solutions had no effect on growth or on C:N ratios of tissues, nor did increases in CO2 levels cause a decrease in N concentration of plant tissues. Hence, increases in NO3- concentration of the hydroponic solution were not necessary to maintain the N status of the plants or to maximize the growth response to elevated CO2.

Robust biological nitrogen fixation in a model grass-bacterial association.

Science.gov (United States)

Pankievicz, Vânia C S; do Amaral, Fernanda P; Santos, Karina F D N; Agtuca, Beverly; Xu, Youwen; Schueller, Michael J; Arisi, Ana Carolina M; Steffens, Maria B R; de Souza, Emanuel M; Pedrosa, Fábio O; Stacey, Gary; Ferrieri, Richard A

2015-03-01

Nitrogen-fixing rhizobacteria can promote plant growth; however, it is controversial whether biological nitrogen fixation (BNF) from associative interaction contributes to growth promotion. The roots of Setaria viridis, a model C4 grass, were effectively colonized by bacterial inoculants resulting in a significant enhancement of growth. Nitrogen-13 tracer studies provided direct evidence for tracer uptake by the host plant and incorporation into protein. Indeed, plants showed robust growth under nitrogen-limiting conditions when inoculated with an ammonium-excreting strain of Azospirillum brasilense. (11)C-labeling experiments showed that patterns in central carbon metabolism and resource allocation exhibited by nitrogen-starved plants were largely reversed by bacterial inoculation, such that they resembled plants grown under nitrogen-sufficient conditions. Adoption of S. viridis as a model should promote research into the mechanisms of associative nitrogen fixation with the ultimate goal of greater adoption of BNF for sustainable crop production. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

Nitrogenous fertilizer uptake by guinea grass in several growth flushes

International Nuclear Information System (INIS)

Ambrosano, E.J.; Ambrosano, G.M.B.

1996-01-01

Nitrogen recovery was evaluated by the 15 N absorption by guineagrass cv. Tobiata. 15 N fertilizer was applied in February, March, May, June, August and September, in posts containing 5 kg of limed and fertilized soil, under greenhouse conditions in Piracicaba, State of Sao Paulo, Brazil. For each 15 N application three cuttings were performed at approximately 5-7 week interval. The following measurements were taken: consumed water, dry matter yield, nitrogen content, nitrogen in the plant derived form the fertilizers (Ndff), nitrogen recovery (R), and the relation between dry matter yield and nitrogen content. It was also determined the number of vegetative and reproductive tillers and apical meristem elimination. Plant growth was reduced after flowing; highest values of nitrogen recovery in the three cutting were observed for 15 N-fertilizer applied in September and August; highest residual effects, in the second and third cuttings after fertilizers 15 N applications, were observed in September, June and August, reaching 22% in September. (author)

Study of nitrogen solubility in multicomponent iron alloys at its pressure in gaseous phase up to 1000kPa

International Nuclear Information System (INIS)

Pomarin, Yu.M.; Grigorenko, G.M.; Latash, Yu.V.; Kanibolotskij, S.A.

1983-01-01

A facility in which metal is melted in a weighed state and nitrogen partical pressure during relting may be charge from 0 to 1000 kPa is developed to investigate nitrogen solubility is liquim metals and alloys. Investigation of nitrogen solubility was performed using samples of 03Kh25N5AM3 steel and Kh20N5, Kh20N10, Kh40N10, Kh40N20 alloys. Positive deflection of [N]=f(√Psub(Nsub(2))) dependence from the Henry law is shown to be observed in the Kh40N10 alloy in the 100-1000 kPa pressure range. In this case the vatue of positive deflection decreases with temperature growth and at T=2273 K nitrogen solubility in the alloy submits to the law of square root. An equation permitting to calculate nitrogen solubility in alloys of Fe-Cr-Ni and Fe-Cr-Mn systems in the 0 to 1000 kPa range of nitrogen partial pressures is obtained

Growth of Rhodococcus sp. strain BCP1 on gaseous n-alkanes: new metabolic insights and transcriptional analysis of two soluble di-iron monooxygenase genes

Directory of Open Access Journals (Sweden)

Martina eCappelletti

2015-05-01

Full Text Available Rhodococcus sp. strain BCP1 was initially isolated for its ability to grow on gaseous n-alkanes, which act as inducers for the co-metabolic degradation of low-chlorinated compounds. Here, both molecular and metabolic features of BCP1 cells grown on gaseous and short-chain n-alkanes (up to n-heptane were examined in detail. We show that propane metabolism generated terminal and sub-terminal oxidation products such as 1- and 2-propanol, whereas 1-butanol was the only terminal oxidation product detected from butane metabolism. Two gene clusters, prmABCD and smoABCD – coding for soluble di-iron monooxgenases (SDIMOs involved in gaseous n-alkanes oxidation – were detected in the BCP1 genome. By means of reverse transcriptase-quantitative PCR (RT-qPCR analysis, a set of substrates inducing the expression of the sdimo genes in BCP1 were assessed as well as their transcriptional repression in the presence of sugars, organic acids or during the cell growth on rich medium (Luria Bertani broth. The transcriptional start sites of both the sdimo gene clusters were identified by means of primer extension experiments. Finally, proteomic studies revealed changes in the protein pattern induced by growth on gaseous- (n-butane and/or liquid (n-hexane short-chain n-alkanes as compared to growth on succinate. Among the differently expressed protein spots, two chaperonins and an isocytrate lyase were identified along with oxidoreductases involved in oxidation reactions downstream of the initial monooxygenase reaction step.

Effects of Nitrogen Availability and Form on Phytoplankton Growth in a Eutrophied Estuary (Neuse River Estuary, NC, USA).

Science.gov (United States)

Cira, Emily K; Paerl, Hans W; Wetz, Michael S

2016-01-01

Nitrogen availability and form are important controls on estuarine phytoplankton growth. This study experimentally determined the influence of urea and nitrate additions on phytoplankton growth throughout the growing season (March 2012, June 2011, August 2011) in a temperate, eutrophied estuary (Neuse River Estuary, North Carolina, USA). Photopigments (chlorophyll a and diagnostic photopigments: peridinin, fucoxanthin, alloxanthin, zeaxanthin, chlorophyll b) and microscopy-based cell counts were used as indicators of phytoplankton growth. In March, the phytoplankton community was dominated by Gyrodinium instriatum and only fucoxanthin-based growth rates were stimulated by nitrogen addition. The limited response to nitrogen suggests other factors may control phytoplankton growth and community composition in early spring. In June, inorganic nitrogen concentrations were low and stimulatory effects of both nitrogen forms were observed for chlorophyll a- and diagnostic photopigment-based growth rates. In contrast, cell counts showed that only cryptophyte and dinoflagellate (Heterocapsa rotundata) growth were stimulated. Responses of other photopigments may have been due to an increase in pigment per cell or growth of plankton too small to be counted with the microscopic methods used. Despite high nitrate concentrations in August, growth rates were elevated in response to urea and/or nitrate addition for all photopigments except peridinin. However, this response was not observed in cell counts, again suggesting that pigment-based growth responses may not always be indicative of a true community and/or taxa-specific growth response. This highlights the need to employ targeted microscopy-based cell enumeration concurrent with pigment-based technology to facilitate a more complete understanding of phytoplankton dynamics in estuarine systems. These results are consistent with previous studies showing the seasonal importance of nitrogen availability in estuaries, and also

The growth of irradiated candida utilis in molasses media with and without nitrogen

International Nuclear Information System (INIS)

Andini, L.; Harsoyo; Siagian, E.G.

1987-01-01

The growth of irradiated candida utilis in molassea media with and without nitrogen. The experiment has been done to compare the growth of C.utilis on molasses media containing nitrogen and without nitrogen. The C.utilis irradiated with gamma rays from 60 Co (Gamma Cell 220) with different exposure i.e. 0,21, 43, 64, 85 and 106 Gy and then inoculated on 2% molasses medium with and without N, and incubated at 28 0 +- 2 0 C for 0 and 1 day. Parameters observed were the number of colony, the size of colony growth on 2% molasses medium with and without N. The results showed that the growth in media molasses with N was different from that without N. The incubation effect seemed to be a significant, while the effect of irradiation was not significant, which was probably due to the insufficient dose used for inducing stimulation. The interaction between the added Nand incubation was also significant. 13 refs

Regulation of nitrogen uptake and assimilation: Effects of nitrogen source and root-zone and aerial environment on growth and productivity of soybean

Science.gov (United States)

Raper, C. David, Jr.

1994-01-01

The interdependence of root and shoot growth produces a functional equilibrium as described in quantitative terms by numerous authors. It was noted that bean seedlings grown in a constant environment tended to have a constant distribution pattern of dry matter between roots and leaves characteristic of the set of environmental conditions. Disturbing equilibrium resulted in a change in relative growth of roots and leaves until the original ratio was restored. To define a physiological basis for regulation of nitrogen uptake within the balance between root and shoot activities, the authors combined a partioning scheme and a utilization priority assumption in which: (1) all carbon enters the plant through photosynthesis in leaves and all nitrogen enters the plant through active uptake by roots, (2) nitrogen uptake by roots and secretion into the xylem for transport to the shoots are active processes, (3) availability of exogenous nitrogen determines concentration of soluble carbohydrates within the roots, (4) leaves are a source and a sink for carbohydrates, and (5) the requirement for nitrogen by leaf growth is proportionally greater during initiation and early expansion than during later expansion.

Protein as chemical cue: non-nutritional growth enhancement by exogenous protein in Pseudomonas putida KT2440.

Directory of Open Access Journals (Sweden)

Hiren Joshi

Full Text Available Research pertaining to microbe-microbe and microbe-plant interactions has been largely limited to small molecules like quorum sensing chemicals. However, a few recent reports have indicated the role of complex molecules like proteins and polysaccharides in microbial communication. Here we demonstrate that exogenous proteins present in culture media can considerably accelerate the growth of Pseudomonas putida KT2440, even when such proteins are not internalized by the cells. The growth enhancement is observed when the exogenous protein is not used as a source of carbon or nitrogen. The data show non-specific nature of the protein inducing growth; growth enhancement was observed irrespective of the protein type. It is shown that growth enhancement is mediated via increased siderophore secretion in response to the exogenous protein, leading to better iron uptake. We highlight the ecological significance of the observation and hypothesize that exogenous proteins serve as chemical cues in the case of P.putida and are perceived as indicator of the presence of competitors in the environment. It is argued that enhanced siderophore secretion in response to exogenous protein helps P.putida establish numerical superiority over competitors by way of enhanced iron assimilation and quicker utilization of aromatic substrates.

Halotolerant rhizobacteria promote growth and enhance salinity tolerance in peanut

Directory of Open Access Journals (Sweden)

Sandeep Sharma

2016-10-01

Full Text Available Use of Plant growth promoting rhizobacteria (PGPR is a promising strategy to improve the crop production under optimal or sub-optimal conditions. In the present study, five diazotrophic salt tolerant bacteria were isolated from the roots of a halophyte, Arthrocnemum indicum. The isolates were partially characterized in vitro for plant growth promoting traits and evaluated for their potential to promote growth and enhanced salt tolerance in peanut. The 16S rRNA gene sequence homology indicated that these bacterial isolates belong to the genera, Klebisiella, Pseudomonas, Agrobacterium and Ochrobactrum. All isolates were nifH positive and able to produce indole -3-acetic acid (ranging from 11.5 to 19.1 µg ml-1. The isolates showed phosphate solubilisation activity (ranging from 1.4 to 55.6 µg phosphate /mg dry weight, 1-aminocyclopropane-1-carboxylate deaminase activity (0.1 to 0.31 µmol α-kB/µg protein/h and were capable of reducing acetylene in acetylene reduction assay (ranging from 0.95 to 1.8 µmol C2H4 mg protein/h. These isolates successfully colonized the peanut roots and were capable of promoting the growth under non-stress condition. A significant increase in total nitrogen (N content (up to 76% was observed over the non-inoculated control. All isolates showed tolerance to NaCl ranging from 4-8% in nutrient broth medium. Under salt stress, inoculated peanut seedlings maintained ion homeostasis, accumulated less reactive oxygen species (ROS and showed enhanced growth compared to non-inoculated seedlings. Overall, the present study has characterized several potential bacterial strains that showed an enhanced growth promotion effect on peanut under control as well as saline conditions. The results show the possibility to reduce chemical fertilizer inputs and may promote the use of bio-inoculants.

Liquid nitrogen enhancement of alpha particle tracks in a polycarbonate detector

International Nuclear Information System (INIS)

Pilione, L.J.

1977-01-01

Makrofol-E polycarbonate detectors were exposed to 1 to 3 MeV alpha particles and subsequently immersed in liquid nitrogen for various periods of time. The influence of the liquid nitrogen on the track recording properties of the detector has been found by measuring the track densities and diameters. Track densities increase with immersion time with a maximum gain of approximately 9% after 1200 min in liquid nitrogen. Track enhancement decreases with waiting time between the end of alpha particle exposure and the beginning of liquid nitrogen immersion. Track diameters decrease with time after passage of the particles and this process is accelerated by immersion in liquid nitrogen. (author)

Nitrogen for growth of stock plants and production of strawberry runner tips

Directory of Open Access Journals (Sweden)

Djeimi Isabel Janisch

2012-01-01

Full Text Available The objective of this research was to determine growth and dry matter partitioning among organs of strawberry stock plants under five Nitrogen concentrations in the nutrient solution and its effects on emission and growth of runner tips. The experiment was carried out under greenhouse conditions, from September 2010 to March 2011, in a soilless system with Oso Grande and Camino Real cultivars. Nitrogen concentrations of 5.12, 7.6, 10.12 (control, 12.62 and 15.12 mmol L-1 in the nutrient solution were studied in a 5x2 factorial randomised experimental design. All runner tips bearing at least one expanded leaf (patent requested were collected weekly and counted during the growth period. The number of leaves, dry matter (DM of leaves, crown and root, specific leaf area and leaf area index (LAI was determined at the final harvest. Increasing N concentration in the nutrient solution from 5.12 to 15.12 mmol L-1 reduces growth of crown, roots and LAI of strawberry stock plants but did not affect emission and growth of runner tips. It was concluded that for the commercial production of plug plants the optimal nitrogen concentration in the nutrient solution should be 5.12 mmol L-1.

Effect of nitrogen regime on microalgal lipid production during mixotrophic growth with glycerol.

Science.gov (United States)

Paranjape, Kiran; Leite, Gustavo B; Hallenbeck, Patrick C

2016-08-01

Mixotrophic growth of microalgae to boost lipid production is currently under active investigation. Such a process could be of practical importance if a cheap source of organic carbon, such as waste glycerol from biodiesel production, could be used. Several previous studies have already demonstrated that this carbon source can be used by different indigenous strains of microalgae. In this study it is shown that different nitrogen limitation strategies can be applied to further increase lipid production during growth with glycerol. In one strategy, cultures were grown in nitrogen replete medium and then resuspended in nitrogen free medium. In a second strategy, cultures were grown with different initial concentrations of nitrate. Lipid production by the two microalgal strains used, Chlorella sorokiniana (PCH02) and Chlorella vulgaris (PCH05), was shown to be boosted by strategies of nitrogen limitation, but they responded differently to how nitrogen limitation was imposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of nitrogen salts on the growth of Ceratonia siliqua L. Shoot cultures

Directory of Open Access Journals (Sweden)

Vinterhalter Branka

2007-01-01

Full Text Available Effects of reduced nitrogen salt nutriton on the growth, lenticel hypertrophy and anthocyanin accumulation of carob (Ceratonia siliqua L. shoot cultures were investigated in conditions of light and darkness. Growth of shoot cultures was not significantly affected until nitrogen salts were reduced to less than ¼ of full-strength MS (Murashige and Skoog, 1962 values. Cultures in darkness were less affected and their main shoots even increased in length. Appearance of hypertrophied lenticels in light decreased, while in darkness they were absent in all treatments. Reduced nitrogen salt nutrition strongly affected anthocyanin accumulation of shoots and leaves, which greatly increased in both light and darkness. .

Development of NF3 Deposit Removal Technology for the Portsmouth Gaseous Diffusion Plant

International Nuclear Information System (INIS)

Scheele, R.D.; McNamara, B.K.; Rapko, B.M.; Edwards, M.K.; Kozelisky, A.E.; Daniel, R.C.; McSweeney, T.I.; Maharas, S.J.; Weaver, P.J.; Iwamasa, K.J.; Kefgen, R.B.

2006-01-01

This paper summarizes the Battelle, Stoller, and WASTREN (BSW) team's efforts, to date, in support of the United States Department of Energy's plans to remove uranium and technetium deposits before decommissioning the Portsmouth Gaseous Diffusion Plant. The BSW team investigated nitrogen trifluoride (NF 3 ) as a safer yet effective alternative gaseous treatment to the chlorine trifluoride (ClF 3 )-elemental fluorine (F 2 ) treatment currently used to remove uranium and technetium deposits from the uranium enrichment cascade. Both ClF 3 and F 2 are highly reactive, toxic, and hazardous gases, while NF 3 , although toxic [1], is no more harmful than moth balls [2]. BSW's laboratory thermo-analytical and laboratory-scale prototype studies with NF 3 established that thermal NF 3 can effectively remove likely and potential uranium (UO 2 F 2 and UF 4 ) and technetium deposits (a surrogate deposit material, TcO 2 , and pertechnetates) by conversion to volatile compounds. Our engineering evaluations suggest that NF 3 's effectiveness could be enhanced by combining with a lesser concentration of ClF 3 . BSW's and other's studies indicate compatibility with Portsmouth materials of construction (aluminum, copper, and nickel). (authors)

Effect of vanadium and tungsten on nitrogen fixation and the growth of Medicago sativa

Energy Technology Data Exchange (ETDEWEB)

Jha, K K

1969-01-01

In sand culture, it was found that vanadium had no stimulatory effect on nitrogen content or the growth of Medicago sativa inoculated with an effective strain of Rhizobium meliloti or supplied with ammonium nitrate. At the level of 500 ppm it reduced the plant growth, the inhibitory effect being particularly severe on the root. On the other hand tungsten increased nitrogen fixation and the dry matter yield of the inoculated plants. The results are suggestive of a direct role of tungsten in symbiotic nitrogen fixation. 4 references, 2 tables.

Isotope exchange investigation of nitrogen redistribution in expanded austenite

DEFF Research Database (Denmark)

Christiansen, Thomas Lundin; Drouet, M.; Martinavičius, A.

2013-01-01

Sequential plasma and gaseous nitriding of Fe–18Cr–10Ni–3Mo stainless steel at 390°C with 14N and 15N isotopes followed by denitriding in flowing hydrogen was investigated. Redistribution of plasma-inserted nitrogen atoms (15N) by subsequent gaseous nitriding (14N) was observed. Denitriding after...

Developments in nitrogen generators

International Nuclear Information System (INIS)

Ayres, C.L.; Abrardo, J.M.; Himmelberger, L.M.

1984-01-01

Three process cycles for the production of nitrogen by the cryogenic separation of air are described in detail. These cycles are: (1) a waste expander cycle; (2) an air expander cycle; and (3) a cycle for producing large quantities of gaseous nitrogen. Each cycle has distinct advantages for various production ranges and delivery pressures. A dicussion of key parameters that must be considered when selecting a cycle to meet specific product requirements is presented. The importance of high plant reliability and a dependable liquid nitrogen back up system is also presented. Lastly, a discussion of plant safety dealing with the hazards of nitrogen, enriched oxygen, and hydrocarbons present in the air is reviewed

Study of nitrogen injection to enhance forced convection for gas fast reactors

International Nuclear Information System (INIS)

Tauveron, N.; Dor, I.; Bentivoglio, F.

2011-01-01

Highlights: → The present study concerns the use of blowers in case of nitrogen injection. It is a well-known fact that heavier gases (than helium) enhance natural circulation. The use of such heavier gases (nitrogen is considered here) can also enhance forced convection. → A specific work on the impact of the use of alternative gas on blower behaviour is presented. → These developments are used in a simplified system analysis and in a complete transient behaviour analysis in depressurised situations computed with the CATHARE2 code. - Abstract: In the frame of the international forum GenIV, the gas fast reactor is considered as a promising concept, combining the benefits of fast spectrum and high temperature, using helium as coolant. In the current preliminary viability GFR studies safety system relies on blowers in case of depressurised conditions. The present study concerns the use of blowers in case of nitrogen injection. It is a well-known fact that heavier gases (than helium) enhance natural circulation. The use of such gases (nitrogen is considered) can also enhance forced convection. A specific work on the impact of the use of alternative gas on blower behaviour is presented. Transient behaviours in depressurised situations are computed with the CATHARE2 code and analyzed.

Enhancement of lipid production in two marine microalgae under different levels of nitrogen and phosphorus deficiency.

Science.gov (United States)

Adenan, Nurul Salma; Yusoff, Fatimah Md; Medipally, Srikanth Reddy; Shariff, M

2016-07-01

Microalgae are important food sources for aquaculture animals. Among the different factors which influence the biochemical composition of microalgae, nitrogen and phosphorus are two of the most important nutrient sources for growth and development. The present study aimed to assess the effects of nitrogen and phosphorus deficiency on lipid production of Chlorella sp. and Chaetoceros calcitrans. Early stationary phase culture of these species were exposed to different stress levels of nitrogen and phosphorus (25%, 50% and 75% of the full NO(3)-N and PO(4)-P concentration in the Conway media), and solvent extraction and gas-liquid chromatography methods were performed for analysis of lipid and fatty acid composition. The results revealed that lipid production in these two species significantly increased (Pnitrogen and phosphorus decreased. The fatty acid proportion remained unaffected under nitrogen deficiency, while phosphorus limitation resulted in a decrease of saturated fatty acids and promoted a higher content of omega-3 fatty acids in these species. The protein and carbohydrate levels were also altered under limited nutrients. Therefore, these conditions could be used for enhanced lipid production in microalgae for aquaculture and other industrial applications.

Enhanced nitrogen removal in trickling filter plants.

Science.gov (United States)

Dai, Y; Constantinou, A; Griffiths, P

2013-01-01

The Beaudesert Sewage Treatment Plant (STP), originally built in 1966 and augmented in 1977, is a typical biological trickling filter (TF) STP comprising primary sedimentation tanks (PSTs), TFs and humus tanks. The plant, despite not originally being designed for nitrogen removal, has been consistently achieving over 60% total nitrogen reduction and low effluent ammonium concentration of less than 5 mg NH3-N/L. Through the return of a NO3(-)-rich stream from the humus tanks to the PSTs and maintaining an adequate sludge age within the PSTs, the current plant is achieving a substantial degree of denitrification. Further enhanced denitrification has been achieved by raising the recycle flows and maintaining an adequate solids retention time (SRT) within the PSTs. This paper describes the approach to operating a TF plant to achieve a high degree of nitrification and denitrification. The effectiveness of this approach is demonstrated through the pilot plant trial. The results from the pilot trial demonstrate a significant improvement in nitrogen removal performance whilst maximising the asset life of the existing infrastructure. This shows great potential as a retrofit option for small and rural communities with pre-existing TFs that require improvements in terms of nitrogen removal.

Analysis of coffee (Coffea arabica L.) performance in relation to radiation level and rate of nitrogen supply II. Uptake and distribution of nitrogen, leaf photosynthesis and first bean yields

NARCIS (Netherlands)

Bote, Adugna Debela; Zana, Zewdneh; Ocho, Fikre L.; Vos, Jan

2018-01-01

Natural supply of nitrogen is often limiting coffee production. From the viewpoints of growth and biomass production, adequate nitrogen supply is important. Growing coffee under full sunlight not only enhances potential yields but also increases demands for nitrogen fertilizer, the extent of which

Growth of planetisimals in a gaseous ring

International Nuclear Information System (INIS)

Hourigan, K.

1981-01-01

The aggregation of planetesimals in a gaseous ring leads to the development of a dominant body amongst the planetesimal population. The presence of the gas in the form of a differentially rotating ring serves to constrain the orbits of the planetesimals and grains to within a thin toroidal region through the action of gas drag. This situation allows for the efficient aggregation of bodies and, as a result of the low resultant relative velocites, the minimization of collisional fragmentation effects

Importance of molybdenum in the nitrogen metabolism of microorganisms and higher plants

Energy Technology Data Exchange (ETDEWEB)

Mulder, E G

1948-01-01

The effect of molybdenum on the growth of microorganisms and higher plants and on some well-defined biochemical reactions was investigated. Results indicate that Aspergillus niger requires small amounts of molybdenum when growing in a culture solution supplied with nitrate nitrogen. With ammonium sulfate as a source of nitrogen, the response of the fungus to molybdenum was much smaller. It was shown that this different response of Aspergillus to molybdenum was not brought about by a difference in purity of both nitrogen compounds used, nor by a difference in absorption of the molybdenum impurity, but by a considerably higher requirement of molybdenum in a medium with nitrate nitrogen. The growth-rate curve and the increasing sporulation of Aspergillus niger with increasing amounts of molybdenum were used in estimating very small amounts of this element in various materials. In culture solution experiments with tomato, barley and oat plants the effect of traces of molybdenum on the growth of these plants was investigated. In good agreement with the results of the experiments with Aspergillus and denitrifying bacteria it could be shown that in the green plant as in these microorganisms molybdenum is acting as a catalyst in nitrate reduction. In experiments with Azotobacter chroococcum and leguminous plants the effect of molybdenum on the fixation of gaseous N/sub 2/ was studied. In culture solutions with pea plants the effect of molybdenum on the nitrogen fixation of the nodules was investigated. In the absence of molybdenum as well as in a complete nutrient medium many nodules were formed. 30 references, 6 figures, 16 tables.

Growth, photosynthesis and nitrogen metabolism in soybean varieties after exclusion of the UV-B and UV-A/B components of solar radiation

OpenAIRE

Sanjay Singh Baroniya; Sunita Kataria; Govind Prakash Pandey; Kadur N. Guruprasad

2014-01-01

A field experiment was conducted to study the impact of the exclusion of the solar UV components on growth, photosynthesis and nitrogen metabolism in soybean (Glycine max) varieties PK-472, Pusa-24, JS 71-05, JS-335, NRC-7 and Kalitur. The plants were grown in specially designed UV exclusion chambers wrapped with filters to exclude UV-B or UV-A/B and transmitted all UV. Exclusion of UV significantly enhanced the growth of the aerial parts as well as the growth of the below ground parts in all...

[Effects of simulated nitrogen deposition on weeds growth and nitrogen uptake].

Science.gov (United States)

Jiang, Qiqing; Tang, Jianjun; Chen, Xin; Chen, Jing; Yang, Ruyi; Hu, S

2005-05-01

In this paper, a greenhouse experiment was conducted to study the responses of different functional groups weeds to simulated nitrogen deposition (4.0 g N.m(-2).yr(-1)). Native weed species Poa annua, Lolium perenne, Avena fatua, Medicago lupulina, Trifolium repens, Plantago virginica, Veronica didyma, Echinochloa crusgalli var. mitis, Eleusine indica and Amaranthus spinosus in orchard ecosystem were used test materials, and their above-and underground biomass and nitrogen uptake were measured. The results showed that under simulated N deposition, the total biomass, shoot biomass and root biomass of all weed species tended increase, while the total biomass was differed for different functional groups of weeds. The biomass of C4 grass, legumes and C3 grass was significantly increased under N deposition, while that of C3 and C4 forbs was not significantly impacted. The root/shoot biomass ratio of Avena fatua and Plantago virginica was enhanced by N deposition, but that of Poa annu, Lolium perenne, Medicago lupulina, Trifolium repens and Amarathus spinosus was not impacted significantly. N deposition had no significant effect on plant N concentration, but significantly enhanced the N uptake of all test weed species except Amarathus spinosus, Poa annua and Veronica didyma. was suggested that the further increase of N deposition might speed up the changes of the community structure weed species due to their different responses to N deposition.

Response of maize to reduced urea application combined with compound nitrogen fertilizer synergists

International Nuclear Information System (INIS)

Tian Xiuying; WANG Zhengyin

2006-01-01

Pot and field experiments were conducted to study the response to application rate of urea labeled with 15 N combined with compound nitrogen fertilizer synergists in the growth, yield, uptake and utilization rate of urea of maize. In pot experiment, the standard urea application rate is 120 mg/perpot; in field experiment, the standard urea application rate is 157.5 kg/hm 2 . Maize with 15 N-urea. The results showed that the growth of maize seedling was obviously promoted with appropriate dosage of compound nitrogen fertilizer synergists (20%-60% of N). The treatments of urea application rate reduced by 5%-15% and added compound nitrogen fertilizer synergists, the growth and nitrogen content of maize were not significant changed, and the total 15 N uptake and nitrogen uptake by maize were the same as CK 2 or increased a little. Nitrogen use efficiency of other treatments increased by 5.6%-7.3% comparing with CK, except the treatment of urea application rate reduced by 30%. The apparent utilization rate of nitrogen was enhanced by 7.7%-17.0%. Under the field condition, maize yield, total uptake, net uptake, physiological rate and agronomic use efficiency of nitrogen were the same as CK or increased. The apparent utilization rate of nitrogen was enhanced by 14.8%-15.2% treated with urea reduced by 5%-15% (7.8-23.7 kg/hm 2 ) and added with compound nitrogen fertilizer synergists. It was not helpful for the growth and nitrogen utilization rate of maize when urea reduced by 30% and combined with compound nitrogen fertilizer synergists. As a result, treated with urea decreased by 15% and combined with appropriate dosage of compound nitrogen fertilizer synergists (20% of urea), the growth and yield of maize had litter effect and higher the uptake and utilization of nitrogen. (authors)

Effects of Nitrogen Availability and Form on Phytoplankton Growth in a Eutrophied Estuary (Neuse River Estuary, NC, USA)

Science.gov (United States)

Paerl, Hans W.; Wetz, Michael S.

2016-01-01

Nitrogen availability and form are important controls on estuarine phytoplankton growth. This study experimentally determined the influence of urea and nitrate additions on phytoplankton growth throughout the growing season (March 2012, June 2011, August 2011) in a temperate, eutrophied estuary (Neuse River Estuary, North Carolina, USA). Photopigments (chlorophyll a and diagnostic photopigments: peridinin, fucoxanthin, alloxanthin, zeaxanthin, chlorophyll b) and microscopy-based cell counts were used as indicators of phytoplankton growth. In March, the phytoplankton community was dominated by Gyrodinium instriatum and only fucoxanthin-based growth rates were stimulated by nitrogen addition. The limited response to nitrogen suggests other factors may control phytoplankton growth and community composition in early spring. In June, inorganic nitrogen concentrations were low and stimulatory effects of both nitrogen forms were observed for chlorophyll a- and diagnostic photopigment-based growth rates. In contrast, cell counts showed that only cryptophyte and dinoflagellate (Heterocapsa rotundata) growth were stimulated. Responses of other photopigments may have been due to an increase in pigment per cell or growth of plankton too small to be counted with the microscopic methods used. Despite high nitrate concentrations in August, growth rates were elevated in response to urea and/or nitrate addition for all photopigments except peridinin. However, this response was not observed in cell counts, again suggesting that pigment-based growth responses may not always be indicative of a true community and/or taxa-specific growth response. This highlights the need to employ targeted microscopy-based cell enumeration concurrent with pigment-based technology to facilitate a more complete understanding of phytoplankton dynamics in estuarine systems. These results are consistent with previous studies showing the seasonal importance of nitrogen availability in estuaries, and also

Effect of nitrogen dressings on growth and development of sugar-beet

NARCIS (Netherlands)

Houba, V.J.G.

1973-01-01

The growth and development of sugar-beet with different nitrogen dressings was studied by measurement of leaf area and of dry weight and chemical composition (inorganic cations and anions) of several plant parts during the growth season.

For a correct interpretation of the data, the losses in

Effect of nitrogen supply on leaf appearance, leaf growth, leaf nitrogen economy and photosynthetic capacity in maize (Zea mays L.)

NARCIS (Netherlands)

Vos, J.; Putten, van der P.E.L.; Birch, C.J.

2005-01-01

Leaf area growth and nitrogen concentration per unit leaf area, Na (g m-2 N) are two options plants can use to adapt to nitrogen limitation. Previous work indicated that potato (Solanum tuberosum L.) adapts the size of leaves to maintain Na and photosynthetic capacity per unit leaf area. This paper

Nitrogen deposition does not enhance Sphagnum decomposition.

Science.gov (United States)

Manninen, S; Kivimäki, S; Leith, I D; Leeson, S R; Sheppard, L J

2016-11-15

Long-term additions of nitrogen (N) to peatlands have altered bryophyte growth, species dominance, N content in peat and peat water, and often resulted in enhanced Sphagnum decomposition rate. However, these results have mainly been derived from experiments in which N was applied as ammonium nitrate (NH4NO3), neglecting the fact that in polluted areas, wet deposition may be dominated either by NO3(-) or NH4(+). We studied effects of elevated wet deposition of NO3(-) vs. NH4(+) alone (8 or 56kgNha(-1)yr(-1) over and above the background of 8kgNha(-1)yr(-1) for 5 to 11years) or combined with phosphorus (P) and potassium (K) on Sphagnum quality for decomposers, mass loss, and associated changes in hummock pore water in an ombrotrophic bog (Whim). Adding N, especially as NH4(+), increased N concentration in Sphagnum, but did not enhance mass loss from Sphagnum. Mass loss seemed to depend mainly on moss species and climatic factors. Only high applications of N affected hummock pore water chemistry, which varied considerably over time. Overall, C and N cycling in this N treated bog appeared to be decoupled. We conclude that moss species, seasonal and annual variation in climatic factors, direct negative effects of N (NH4(+) toxicity) on Sphagnum production, and indirect effects (increase in pH and changes in plant species dominance under elevated NO3(-) alone and with PK) drive Sphagnum decomposition and hummock C and N dynamics at Whim. Copyright © 2016 Elsevier B.V. All rights reserved.

Regularities of growth, condensation, solution of vapour and gaseous bubbles in turbulent flows

International Nuclear Information System (INIS)

Avdeev, A.A.

1988-01-01

Corrections for interphase transfer exchange intensity and for bubbles dynamics in the forced turbulent flow as well are obtained on the basis of the surface periodical restoration model. Analysis of the effects, caused by turbulence additional generation due to bubbles floating-up within gravity field, is carried out. Formulae for calculating interphase heat and mass transfer at bubbling are suggested. Application limits for the developed model are determined. Comparison of calculation results according to the derived universal dependence with experimental data on growth rates and condensation of vapour bubble, and on solution rates of gaseous bubbles in water (Re=8x10 3 -2x10 6 ; Pr0.83-568, pressure up to 10 MPa) has revealed their good agreeme nt

Growth response of four freshwater algal species to dissolved organic nitrogen of different concentration and complexity

DEFF Research Database (Denmark)

Fiedler, Dorothea; Graeber, Daniel; Badrian, Maria

2015-01-01

1. Dissolved organic nitrogen (DON) compounds dominate the nitrogen pool of many lakes, but their importance as nitrogen sources for freshwater phytoplankton is not fully understood. Previous growth experiments demonstrated the availability of urea and amino acids but often at unnaturally high...... (DCAA), natural organic matter (NOM)) or with nitrate as the sole nitrogen source. Monocultures of Chlamydomonas spp., Cyclotella meneghiniana, Microcystis aeruginosa and Anabaena flos-aquae were incubated with dissolved nitrogen compounds at concentrations ranging from 0.01 to 0.5 mg N L−1, which...... and their compound preferences. Therefore, DON composition can influence biomass and structure of phytoplankton communities. 6. These experiments demonstrate the importance of the main DON compounds for phytoplankton growth when no inorganic nitrogen is available. DON should in future be included in nitrogen budget...

Resonance-enhanced two-photon ionization of ions by Lyman alpha radiation in gaseous nebulae.

Science.gov (United States)

Johansson, S; Letokhov, V

2001-01-26

One of the mysteries of nebulae in the vicinity of bright stars is the appearance of bright emission spectral lines of ions, which imply fairly high excitation temperatures. We suggest that an ion formation mechanism, based on resonance-enhanced two-photon ionization (RETPI) by intense H Lyman alpha radiation (wavelength of 1215 angstroms) trapped inside optically thick nebulae, can produce these spectral lines. The rate of such an ionization process is high enough for rarefied gaseous media where the recombination rate of the ions formed can be 10(-6) to 10(-8) per second for an electron density of 10(3) to 10(5) per cubic centimeter in the nebula. Under such conditions, the photo-ions formed may subsequently undergo further RETPI, catalyzed by intense He i and He ii radiation, which also gets enhanced in optically thick nebulae that contain enough helium.

Effects of organic nitrogen and carbon sources on mycelial growth ...

African Journals Online (AJOL)

STORAGESEVER

2009-10-19

Oct 19, 2009 ... mycelial growth and polysaccharides production and their optimization in the ... Soybean meal was selected as the optimal organic nitrogen source for its significant ..... economy and high yield in industrial production. There-.

Growth, photosynthesis and nitrogen metabolism in soybean varieties after exclusion of the UV-B and UV-A/B components of solar radiation

Directory of Open Access Journals (Sweden)

Sanjay Singh Baroniya

2014-12-01

Full Text Available A field experiment was conducted to study the impact of the exclusion of the solar UV components on growth, photosynthesis and nitrogen metabolism in soybean (Glycine max varieties PK-472, Pusa-24, JS 71-05, JS-335, NRC-7 and Kalitur. The plants were grown in specially designed UV exclusion chambers wrapped with filters to exclude UV-B or UV-A/B and transmitted all UV. Exclusion of UV significantly enhanced the growth of the aerial parts as well as the growth of the below ground parts in all of the six soybean varieties. Nitrate reductase activity (NRA was significantly reduced, whereas leghemoglobin (Lb content, total soluble protein, net photosynthesis (Pn and α-tocopherol content were enhanced after UV exclusion. The exclusion of solar UV-A/B enhanced all parameters to a larger extent than the exclusion of solar UV-B in four of the six varieties of soybean except for NRC-7 and Kalitur. These two varieties responded more to UV-B exclusion compared to UV-A/B exclusion. A significant inverse correlation between the NRA and the number of nodules per plant was observed. The extent of response in all parameters was greater in PK-472 and JS71-05 than that in Kalitur and JS-335 after UV exclusion. The exclusion of UV augmented the growth of nodules, Lb content and α-tocopherol levels and conferred higher rates of Pn to support better growth of nodules. Control plants (+ UV-A/B seemed to fulfill their N demand through the assimilation of NO3− resulting in lower symbiotic nitrogen fixation and higher NR activity.

Interspecific correlates of plasticity in relative growth rate following a decrease in nitrogen availability.

Science.gov (United States)

Useche, Antonio; Shipley, Bill

2010-02-01

Nitrogen availability varies greatly over short time scales. This requires that a well-adapted plant modify its phenotype by an appropriate amount and at a certain speed in order to maximize growth and fitness. To determine how plastic ontogenetic changes in each trait interact and whether or not these changes are likely to maximize growth, ontogenetic changes in relative growth rate (RGR), net assimilation rate (NAR), specific leaf area (SLA) and root weight ratio (RWR), before and after a decrease in nitrogen supply, were studied in 14 herbaceous species. Forty-four plants of each species were grown in hydroponic culture under controlled conditions in a control treatment where the supply of nitrogen remained constant at 1 mm, and in a stress treatment where the nitrogen supply was abruptly decreased from 1 to 0.01 mm during the growth period. In the treatment series, and in comparison with the control, NAR and RGR decreased, RWR increased, and SLA did not change except for the timing of ontogenetic change. Species having greater increases in the maximum rate of change in RWR also had smaller reductions in RGR; plasticity in RWR is therefore adaptive. In contrast, species which showed a greater decrease in NAR showed stronger reductions in RGR; plasticity in NAR is therefore not adaptive. Plasticity in RGR was not related to plasticity in SLA. There were no significant relationships among the plasticities in NAR, RWR or SLA. Potentially fast-growing species experienced larger reductions in RGR following the nitrogen reduction. These results suggest that competitive responses to interspecific competition for nitrogen might be positively correlated with the plasticity in the maximum rate of change in RWR in response to a reduction in nitrogen supply.

Retention of gaseous isotopes

International Nuclear Information System (INIS)

Yarbro, O.O.; Mailen, J.C.; Stephenson, M.J.

1977-01-01

Retention of gaseous fission products during fuel reprocessing has, in the past, been limited to a modest retention of 131 I when processing fuels decayed less than about 180 days. The projected rapid growth of the nuclear power industry along with a desire to minimize environmental effects is leading to the reassessment of requirements for retention of gaseous fission products, including 131 I, 129 I, 85 Kr, 3 H, and 14 C. Starting in the late 1960s, a significant part of the LMFBR reprocessing development program has been devoted to understanding the behavior of gaseous fission products in plant process and effluent streams and the development of advanced systems for their removal. Systems for iodine control include methods for evolving up to 99% of the iodine from dissolver solutions to minimize its introduction and distribution throughout downstream equipment. An aqueous scrubbing system (Iodox) using 20 M HNO 3 as the scrubbing media effectively removes all significant iodine forms from off-gas streams while handling the kilogram quantities of iodine present in head-end and dissolver off-gas streams. Silver zeolite is very effective for removing iodine forms at low concentration from the larger-volume plant off-gas streams. Removal of iodine from plant liquid effluents by solid sorbents either prior to or following final vaporization appears feasible. Krypton is effectively released during dissolution and can be removed from the relatively small volume head-end and dissolver off-gas stream. Two methods appear applicable for removal and concentration of krypton: (1) selective absorption in fluorocarbons, and (2) cryogenic absorption in liquid nitrogen. The fluorocarbon absorption process appears to be rather tolerant of the normal contaminants (H 2 O, CO 2 , NOsub(x), and organics) present in typical reprocessing plant off-gas whereas the cryogenic system requires an extensive feed gas pretreatment system. Retention of tritium in a reprocessing plant is

Understanding nitrate uptake, signaling and remobilisation for improving plant nitrogen use efficiency.

Science.gov (United States)

Kant, Surya

2018-02-01

The majority of terrestrial plants use nitrate as their main source of nitrogen. Nitrate also acts as an important signalling molecule in vital physiological processes required for optimum plant growth and development. Improving nitrate uptake and transport, through activation by nitrate sensing, signalling and regulatory processes, would enhance plant growth, resulting in improved crop yields. The increased remobilisation of nitrate, and assimilated nitrogenous compounds, from source to sink tissues further ensures higher yields and quality. An updated knowledge of various transporters, genes, activators, and microRNAs, involved in nitrate uptake, transport, remobilisation, and nitrate-mediated root growth, is presented. An enhanced understanding of these components will allow for their orchestrated fine tuning in efforts to improving nitrogen use efficiency in plants. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Enhanced microalgal lipid production with media engineering of potassium nitrate as a nitrogen source.

Science.gov (United States)

Gour, Rakesh Singh; Bairagi, Madhusudan; Garlapati, Vijay Kumar; Kant, Anil

2018-01-01

Algal biofuels are far from a commercial reality due to the technical challenges associated with their growth and lipid extraction procedures. In this study, we investigated the effect of 4 different media and 5 different nitrogen sources at 5 levels on the growth, biomass and lipid productivity of Scenedesmus sp and Chlorella sp The hypothesis was that a nitrogen source can be identified that provides enough stress to accumulate lipids without compromising significantly on biomass and lipid productivity. A maximum specific growth rate and doubling per day have been observed with algal species using modified BG-11 medium. Among the tested nitrogen sources, 2.5 mM potassium nitrate as a nitrogen constituent of modified BG-11 medium resulted in higher lipid content and productivity in the case of S. dimorphus (29.15%, 15.449 mg L -1 day -1 ). Another noteworthy outcome of the present study lies in the usage of a smaller amount of the nitrogen source, i.e., 2.5 mM, which is found to be 7 times less than the standard BG11 media (17.60 mM sodium nitrate).

Effectiveness of liquid organic-nitrogen fertilizer in enhancing ...

African Journals Online (AJOL)

The ever increasing price of nitrogenous (N) fertilizers coupled with the deleterious effects of imbalanced N fertilizers on the environment necessitates the enhancement of N use efficiency of plants. The objectives of this study were to: (1) Evaluate the uptake of selected nutrients due to application of liquid organic-N ...

Microwave plasma-assisted photoluminescence enhancement in nitrogen-doped ultrananocrystalline diamond film

Directory of Open Access Journals (Sweden)

Yu Lin Liu

2012-06-01

Full Text Available Optical properties and conductivity of nitrogen-doped ultrananocrystal diamond (UNCD films were investigated following treatment with low energy microwave plasma at room temperature. The plasma also generated vacancies in UNCD films and provided heat for mobilizing the vacancies to combine with the impurities, which formed the nitrogen-vacancy defect centers. The generated color centers were distributed uniformly in the samples. The conductivity of nitrogen-doped UNCD films treated by microwave plasma was found to decrease slightly due to the reduced grain boundaries. The photoluminescence emitted by the plasma treated nitrogen-doped UNCD films was enhanced significantly compared to the untreated films.

Intercropping effect on root growth and nitrogen uptake at different nitrogen levels

DEFF Research Database (Denmark)

Ramirez-Garcia, Javier; Martens, Helle Juel; Quemada, Miguel

2015-01-01

of root growth and N foraging for barley (Hordeum vulgare L.) and vetch (Vicia sativa L.), frequently grown in mixtures as cover crops. N was added at 0 (N0), 50 (N1) and 150 (N2) kg N ha−1. The roots discrimination relying on the anatomical and morphological differences observed between dicots......Aims Intercropping legumes and non-legumes may affect the root growth of both components in the mixture, and the non-legume is known to be strongly favored by increasing nitrogen (N) supply. The knowledge of how root systems affect the growth of the individual species is useful for understanding...... the interactions in intercrops as well as for planning cover cropping strategies. The aim of this work was (i) to determine if different levels of N in the topsoil influence root depth (RD) and intensity of barley and vetch as sole crops or as an intercropped mixture and (ii) to test if the choice of a mixture...

Growth and nitrogen metabolism changes in NaCl-stressed tobacco ...

African Journals Online (AJOL)

Growth and nitrogen metabolism changes in NaCl-stressed tobacco (Nicotiana rustica L. var. Souffi) seedlings. Chokri Zaghdoud, Houda Maâroufi-Dguimi, Youssef Ouni, Mokhtar Guerfel, Houda Gouia, Kamel-Eddine Negaz, Ali Ferchichi, Mohamed Debouba ...

CO/sub 2/ enrichment improves recovery of growth and photosynthesis from drought and nitrogen stress in maize

International Nuclear Information System (INIS)

Zong, Y.

2014-01-01

In the context of the increasing risk of extreme drought as a result of climate change and increasing CO/sub 2/ in the future of northwest China, evaluation of crops ability to recover and survive droughts requires further attention. To test the effects of re-watering on plants suffering water and nitrogen limitations in the presence of elevated CO/sub 2/, maize (Zea mays) was planted to experience combined elevated CO/sub 2/ (380 or 750 micro mol/sup -1/, climate chamber), water stress (15% PEG-6000) and nitrogen limitation (5 or 15mM N in Hoagland solutions) and then re-watered at three levels (300mL, 600mL, 900mL per pot of distilled water). When plants were re-watered, drought stressed and N limited plants with ambient CO/sub 2/ increased their water content more than that of elevated CO/sub 2/, while the enhancement of growth rate were negatively related to the increasing plant water content. Elevated CO/sub 2/ could help re-watered seedlings to have higher photosynthetic capacity (Fv/Fm, PSII, Pn,Pn/Tr and Pn/Gs) and new leaf growth under low water content, apart from nitrogen deficiency. The results demonstrated that elevated CO2 could help drought stressed seedlings to maintain higher carbon assimilation rates under low water content, as a result to improve leaf water use efficiency. (author)

Effect of dietary protein to energy ratio on growth and nitrogenous ...

African Journals Online (AJOL)

The effect of dietary protein to energy ratio (P:E) on the growth of dusky kob Argyrosomus japonicus was investigated as a first step towards formulating a practical diet for this potential mariculture species in South Africa. The effects of dietary protein and lipid on growth, feed conversion ratio (FCR) and nitrogenous waste ...

EFFICIENCY OF PRE-TREATMENT OF LEACHATE FROM MUNICIPAL WASTE DUMPS BY GASEOUS DESORPTION (STRIPPING OF AMMONIA

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Justyna Koc-Jurczyk

2017-05-01

Full Text Available The paper studies the efficiency of pre-treatment of landfill leachate by gaseous desorption of ammonia. The research was done on a municipal non-hazardous waste dump in Krosno (Sub-Carpathian Province, Poland. The pretreatment provided a favorable BOD5/COD ratio in leachate. Also concentrations of 16 PAHs and heavy metals did not exceed the legal limits. However, gaseous desorption of ammonia was insufficiently efficient in recovering ammonia nitrogen from leachate.

Natural sources of gaseous pollutants in the atmosphere

Energy Technology Data Exchange (ETDEWEB)

Altshuller, A P

1958-01-01

Various gaseous pollutants including ozone, nitrous oxide, nitric oxide, nitrogen dioxide, methane, hydrogen, formaldehyde, ammonia, hydrogen sulfide, mercaptans, chlorine compounds and free radicals can be formed by natural processes such as ultraviolet photochemical processes in the upper atmosphere and microbiological processes. The modes of formation and destruction of these gases, especially of their concentrations in the atmosphere, and the various reactions in which these gases can participate with each other are discussed in detail. 114 references.

Respiration and nitrogen assimilation: targeting mitochondria-associated metabolism as a means to enhance nitrogen use efficiency.

Science.gov (United States)

Foyer, Christine H; Noctor, Graham; Hodges, Michael

2011-02-01

Considerable advances in our understanding of the control of mitochondrial metabolism and its interactions with nitrogen metabolism and associated carbon/nitrogen interactions have occurred in recent years, particularly highlighting important roles in cellular redox homeostasis. The tricarboxylic acid (TCA) cycle is a central metabolic hub for the interacting pathways of respiration, nitrogen assimilation, and photorespiration, with components that show considerable flexibility in relation to adaptations to the different functions of mitochondria in photosynthetic and non-photosynthetic cells. By comparison, the operation of the oxidative pentose phosphate pathway appears to represent a significant limitation to nitrogen assimilation in non-photosynthetic tissues. Valuable new insights have been gained concerning the roles of the different enzymes involved in the production of 2-oxoglutarate (2-OG) for ammonia assimilation, yielding an improved understanding of the crucial role of cellular energy balance as a broker of co-ordinate regulation. Taken together with new information on the mechanisms that co-ordinate the expression of genes involved in organellar functions, including energy metabolism, and the potential for exploiting the existing flexibility for NAD(P)H utilization in the respiratory electron transport chain to drive nitrogen assimilation, the evidence that mitochondrial metabolism and machinery are potential novel targets for the enhancement of nitrogen use efficiency (NUE) is explored.

Femtosecond Time-Resolved Resonance-Enhanced CARS of Gaseous Iodine at Room Temperature

International Nuclear Information System (INIS)

He Ping; Fan Rong-Wei; Xia Yuan-Qin; Yu Xin; Chen De-Ying; Yao Yong

2011-01-01

Time-resolved resonance-enhanced coherent anti-Stokes Raman scattering (CARS) is applied to investigate molecular dynamics in gaseous iodine. 40 fs laser pulses are applied to create and monitor the high vibrational states of iodine at room temperature (corresponding to a vapor pressure as low as about 35 Pa) by femtosecond time-resolved CARS. Depending on the time delay between the probe pulse and the pump/Stokes pulse pairs, the high vibrational states both on the electronically ground states and the excited states can be detected as oscillations in the CARS transient signal. It is proved that the femtosecond time-resolved CARS technique is a promising candidate for investigating the molecular dynamics of a low concentration system and can be applied to environmental and atmospheric monitoring measurements. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Anthropogenic nitrogen deposition ameliorates the decline in tree growth caused by a drier climate.

Science.gov (United States)

Ibáñez, Inés; Zak, Donald R; Burton, Andrew J; Pregitzer, Kurt S

2018-02-01

Most forest ecosystems are simultaneously affected by concurrent global change drivers. However, when assessing these effects, studies have mainly focused on the responses to single factors and have rarely evaluated the joined effects of the multiple aspects of environmental change. Here, we analyzed the combined effects of anthropogenic nitrogen (N) deposition and climatic conditions on the radial growth of Acer saccharum, a dominant tree species in eastern North American forests. We capitalized on a long-term N deposition study, replicated along a latitudinal gradient, that has been taking place for more than 20 yr. We analyzed tree radial growth as a function of anthropogenic N deposition (ambient and experimental addition) and of summer temperature and soil water conditions. Our results reveal that experimental N deposition enhances radial growth of this species, an effect that was accentuated as temperature increased and soil water became more limiting. The spatial and temporal extent of our data also allowed us to assert that the positive effects of growing under the experimental N deposition are likely due to changes in the physiological performance of this species, and not due to the positive correlation between soil N and soil water holding capacity, as has been previously speculated in other studies. Our simulations of tree growth under forecasted climate scenarios specific for this region also revealed that although anthropogenic N deposition may enhance tree growth under a large array of environmental conditions, it will not mitigate the expected effects of growing under the considerably drier conditions characteristic of our most extreme climatic scenario. © 2018 by the Ecological Society of America.

Nitrogen Fertilization Increases Cottonwood Growth on Old-Field Soil

Science.gov (United States)

B. G. Blackmon; E. H. White

1972-01-01

Nitrogen (150 lb ./acre as NH4N03 ) applied to a 6-year-old eastern cottonwood plantation in an old field on Commerce silt loam soil increased diameter, basal area, and volume growth by 200 percent over untreated controls. The plantation did not respond to 100 pounds P per acre from concentrated superphosphate.

Method of absorbing UF6 from gaseous mixtures in alkamine absorbents

International Nuclear Information System (INIS)

Lafferty, R.H.; Smiley, S.H.; Radimer, K.J.

1976-01-01

A method is described for recovering UF 6 from gaseous mixtures by absorption in a liquid. The liquid absorbent must have a relatively low viscosity and at least one component of the absorbent is an alkamine having less than 3 carbon atoms bonded to the amino nitrogen, less than 2 of the carbon atoms other than those bonded to the amino nitrogen are free of the hydroxy radical and precipitate the absorbed uranium from the absorbent. At least one component of the absorbent is chosen from the group consisting of ethanolamine, diethanolamine, and 3-methyl-3-amino-propane-diol-1,2

Effects of Nitrogen Fertilizers on the Growth and Nitrate Content of Lettuce (Lactuca sativa L.)

Science.gov (United States)

Liu, Cheng-Wei; Sung, Yu; Chen, Bo-Ching; Lai, Hung-Yu

2014-01-01

Nitrogen is an essential element for plant growth and development; however, due to environmental pollution, high nitrate concentrations accumulate in the edible parts of these leafy vegetables, particularly if excessive nitrogen fertilizer has been applied. Consuming these crops can harm human health; thus, developing a suitable strategy for the agricultural application of nitrogen fertilizer is important. Organic, inorganic, and liquid fertilizers were utilized in this study to investigate their effect on nitrate concentrations and lettuce growth. The results of this pot experiment show that the total nitrogen concentration in soil and the nitrate concentration in lettuce increased as the amount of nitrogen fertilizer increased. If the recommended amount of inorganic fertilizer (200 kg·N·ha−1) is used as a standard of comparison, lettuce augmented with organic fertilizers (200 kg·N·ha−1) have significantly longer and wider leaves, higher shoot, and lower concentrations of nitrate. PMID:24758896

Pyrolysis of superfine pulverized coal. Part 3. Mechanisms of nitrogen-containing species formation

International Nuclear Information System (INIS)

Liu, Jiaxun; Jiang, Xiumin; Shen, Jun; Zhang, Hai

2015-01-01

Highlights: • NH 3 and NO formation mechanisms during superfine pulverized coal pyrolysis are investigated. • Influences of temperature, heating rate, particle size, atmosphere, and acid wash on the NH 3 and NO formation are analyzed. • Transformations of nitrogen-containing structures in coal/char during pyrolysis are recognized through XPS observation. • Relationships among nitrogen-containing gaseous species during pyrolysis are discussed. - Abstract: With more stringent regulations being implemented, elucidating the formation mechanisms of nitrogen-containing species during the initial pyrolysis step becomes important for developing new NO x control strategies. However, there is a lack of agreement on the origins of NO x precursors during coal pyrolysis, in spite of extensive investigations. Hence, it is important to achieve a more precise knowledge of the formation mechanisms of nitrogen-contain species during coal pyrolysis. In this paper, pyrolysis experiments of superfine pulverized coal were performed in a fixed bed at low heating rates. The influences of temperature, coal type, particle size and atmosphere on the NH 3 and NO evolution were discussed. There is a central theme to develop knowledge of the relationship between particle sizes and evolving behaviors of nitrogen-containing species. Furthermore, the catalytic role of inherent minerals in coal was proved to be effective on the partitioning of nitrogen during coal pyrolysis. In addition, the conversion pathways of heteroaromatic nitrogen structures in coal/char during pyrolysis were recognized through the X-ray photoelectron spectroscopy (XPS) analysis. Large quantities of pyridinic and quanternary nitrogen functionalities were formed during the thermal degradation. Finally, the relationships among the nitrogen-containing gaseous species during coal pyrolysis were discussed. In brief, a comprehensive picture of the volatile-nitrogen partitioning during coal pyrolysis is obtained in this

Nitrogen diffusion and nitrogen depth profiles in expanded austenite: experimental assessment, numerical simulation and role of stress

DEFF Research Database (Denmark)

Christiansen, Thomas; Dahl, Kristian Vinter; Somers, Marcel A. J.

2008-01-01

during gaseous nitriding, a qualitative discussion of the role of stress on local equilibrium conditions of growing expanded austenite and a discussion of the erroneous concentration dependent diffusivity of nitrogen in expanded austenite as obtained from applying the Boltzmann-Matano method...

Studies on growth, nitrogen and energy metabolism in rats

DEFF Research Database (Denmark)

Thorbek, G; Chwalibog, André; Eggum, B O

1982-01-01

Feed intake, growth, nitrogen retention and energy metabolism were measured in 12 male Wistar rats fed ad lib. for 14 weeks with non-purified diets. The feed intake increased rapidly in 4 weeks time from 16 g/d to 25 g/d, and then it was constant in the following 10 weeks. In relation to metabolic...

Nitrogen fertilization and root growth dynamics of durum wheat for a sustainable production

Directory of Open Access Journals (Sweden)

Donato De Giorgio

2012-07-01

Full Text Available In an area of the Apulian Tavoliere (southern Italy, the effects of three levels of nitrogen fertilization (0, 50 and 100 kg N ha–1 on root development, growth analysis and yield parameters of durum wheat were evaluated. The research was conducted over a four-year period (1994-97. The non-destructive mini-rhizotron method was used to study the root system at stem extension and at the beginning of heading and ripening stages. At the end of tillering and at boot and flowering stages, samples of wheat biomass were taken and subjected to growth analysis. Yield data and the main biometric parameters were collected at harvest time. The doses of nitrogen (N fertilizer 50 and 100 kg N ha–1 had a greater effect on root development in the 20-30 cm soil layer and on epigeal biomass than the control test (N0 without nitrogen fertilization. In the test (N0 the growth of root and epigeal biomass was slower during the first vegetative phases, however, afterwards both of them recovered and the root system was mainly developed in the 30-40 cm soil layer. A better development of root system in deeper soil layers, without nitrogen supply, has allowed the plant to overcome more easily the water-deficit and thermal stresses during the ripening stage. The results of this research have shown that the production of grain with 50 kg ha–1 of N is similar to those of 100 kg ha–1 of N doses and higher than the test without nitrogen fertilization. In this kind of environment can be recommended a nitrogen dose of 50 kg ha–1 for obtaining an increase in grain production with low costs and reduced agricultural sources of pollution.

Effect of nitrogen and fish manure fertilization on growth and chemical composition of lettuce

Science.gov (United States)

Yildirim, Ertan; Kul, Raziye; Turan, Metin; Ekinci, Melek; Alak, Gonca; Atamanalp, Muhammet

2016-04-01

Present experiment was designed to determine the response of various dozes of fish manure (FM) and commercial fertilizers on plant growth, yield and nutrient content of lettuce. The treatments consisted of fish manure, commercial fertilizer and the combination of fish manure and commercial fertilizer with four dozes of nitrogen (0 kg/ha, 100 kg/ha, 150 kg/ha and 200 kg/ha). The results of the study showed that treatments significantly affected the growth and chemical characteristics of lettuce. The best results in regard to plant growth and yield were obtained from 100 and 150 kg kg/ha nitrogen dozes of the combination of fish manure and commercial fertilizer.

Gaseous NO2 effects on stomatal behavior, photosynthesis and respiration of hybrid poplar leaves

Science.gov (United States)

In this study, we used poplar as a model plant and investigated the effects of gaseous nitrogen dioxide (NO2, 4 microliter per liter) on stomatal conductance, photosynthesis, dark- and photorespiration of Populus alba x Populus berolinensis hybrid leaves using the photosynthesis system and scanning...

Effects of growth reducer and nitrogen fertilization on morphological variables, SPAD index, interception of radiation and productivity of wheat

Directory of Open Access Journals (Sweden)

Elvis Felipe Elli

2015-12-01

Full Text Available ABSTRACT The objective of this study was to evaluate the effect of growth reducer and nitrogen fertilization on morphological variables, SPAD index, radiation interception, and grain yield of three cultivars of wheat. The experimental design was a randomized block in factorial scheme 3x5x2, with three cultivars (Mestre, Iguaçú and Itaipú, five nitrogen doses (0, 40, 80, 120, 160 Kg ha-1, and application or no application of a growth reducer, with three replications. The following characteristics were evaluated: plant height, SPAD index, leaf area index (LAI, Global Radiation Interception (GRI and grain yield. The Tukey test (p < 0.05 was used for the comparison between the means of cultivar and growth reducer factors, and for a regression analysis to evaluate N levels. Increasing the dose of nitrogen promotes an increase in LAI of plants of wheat crops differently among cultivars, which leads to a greater degree of global radiation interception. At doses higher or equal to 120 Kg ha-1 of nitrogen, there are significant differences in grain yield between treatments with and without the application of the growth reducer. The significant interaction between growth reducer and nitrogen dose, showed that applications of growth reducer increase the GRI at doses above and below 80 Kg ha-1 of nitrogen. Nitrogen rates of 138 and 109 Kg ha-1 are responsible for maximum grain yields of wheat, which is 4235 and 3787 Kg ha-1 with and without the use of growth reducer, respectively.

Plasma-assisted nitrogen doping of VACNTs for efficiently enhancing the supercapacitor performance

Energy Technology Data Exchange (ETDEWEB)

Mashayekhi, Alireza; Hosseini, Seyed Mahmoud [University of Tehran, Nano-fabricated Energy Devices Laboratory, School of Electrical and Computer Engineering, College of Engineering (Iran, Islamic Republic of); Hassanpour Amiri, Morteza; Namdar, Naser [University of Tehran, Thin Film and Nano-electronics Laboratory, Nano-electronics Centre of Excellence, School of Electrical and Computer Engineering, College of Engineering (Iran, Islamic Republic of); Sanaee, Zeinab, E-mail: z.sanaee@ut.ac.ir [University of Tehran, Nano-fabricated Energy Devices Laboratory, School of Electrical and Computer Engineering, College of Engineering (Iran, Islamic Republic of)

2016-06-15

Nitrogen doping of vertically aligned carbon nanotubes (VACNTs) using plasma-enhanced chemical vapour deposition has been investigated to improve the supercapacitance performance of CNTs. Incorporating electrochemical measurements on the open-ended nitrogen-doped CNTs, showed the achievement of 6 times improvement in the capacitance value. For nitrogen-doped CNTs on silicon substrate, specific capacitance of 60 F g{sup −1} was obtained in 0.5 M KCl solution, with capacity retention ratio above 90 % after cycled at 0.1 A g{sup −1} for 5000 cycles. Using this sample, a symmetric supercapacitance was fabricated which showed the power density of 37.5 kW kg{sup −1}. The facile fabrication approach and its excellent capacitance improvement, propose it as an efficient technique for enhancing the supercapacitance performance of the carbon-based electrodes.

Effects of organic nitrogen and carbon sources on mycelial growth ...

African Journals Online (AJOL)

Grifola umbellate is a famous and expensive Chinese herb medicine and the main medicinal component is polysaccharide mainly produced by its mycelia. Effects of organic nitrogen and carbon resources on mycelial growth and polysaccharides production of a medicinal mushroom, G. umbellate were studied in the ...

Growth and Yield Components of Tomato as Influenced by Nitrogen ...

African Journals Online (AJOL)

yield of tomato, and later application in the growing stages favours fruit development, thus nitrogen has a dramatic effect on tomato growth and development ..... CRBD design in factorial experiment using SAS analytical Software. ..... with relatively fertile soil experimental conditions there is no existence of joint factor.

Bacillus spp. from rainforest soil promote plant growth under limited nitrogen conditions.

Science.gov (United States)

Huang, X-F; Zhou, D; Guo, J; Manter, D K; Reardon, K F; Vivanco, J M

2015-03-01

The aim of this study was to evaluate effects of PGPR (plant growth-promoting rhizobacteria) isolated from rainforest soil on different plants under limited nitrogen conditions. Bacterial isolates from a Peruvian rainforest soil were screened for plant growth-promoting effects on Arabidopsis (Col-0). Four selected isolates including one Bacillus subtilis, two B. atrophaeus and one B. pumilus significantly promoted growth of Zea mays L. and Solanum lycopersicum under greenhouse conditions. Moreover, the PGPRs significantly promoted growth of S. lycopersicum in both low and nitrogen-amended soil conditions. These PGPR strains were further studied to obtain insights into possible mechanisms of plant growth promotion. Volatile chemicals from those isolates promoted Arabidopsis growth, and the expression of genes related to IAA production was induced in the Arabidopsis plants treated with PGPRs. Further, selected PGPR strains triggered induced systemic resistance (ISR) against Pseudomonas syringae pv tomato DC3000 in Arabidopsis. PGPR strains isolated from the rainforest soil promoted the plant growth of Arabidopsis, corn and tomato. New PGPR that have wider adaptability to different crops, soils and environmental conditions are needed to decrease our reliance on agricultural amendments derived from fossil-based fuels. The PGPRs isolated from a nonagricultural site constitute new plant growth-promoting strains that could be developed for agricultural uses. © 2014 The Society for Applied Microbiology.

Nitrogenous air pollutants: Chemical and biological implications

International Nuclear Information System (INIS)

Grosjean, D.

1979-01-01

Theoretical and experimental studies on the health effects and chemistry of gaseous and particulate nitrogenous air pollutants are presented. Specific topics include Fourier transform infrared studies of nitrogenous compounds, the mechanism of peroxynitric acid formation, N-nitroso compounds in the air, the chemical transformations of nitrogen oxides during the sampling of combustion products, the atmospheric chemistry of peroxy nitrates, and the effects of nitrogen dioxide on lung metabolism. Attention is also given to the interaction of nitrogen oxides and aromatic hydrocarbons under simulated atmospheric conditions, the characterization of particulate amines, the role of ammonia in atmospheric aerosol chemistry, the relationship between sulfates and nitrates and tropospheric measurements of nitric acid vapor and particulate nitrates

Correlation between Fatigue Crack Growth Behavior and Fracture Surface Roughness on Cold-Rolled Austenitic Stainless Steels in Gaseous Hydrogen

Directory of Open Access Journals (Sweden)

Tai-Cheng Chen

2018-03-01

Full Text Available Austenitic stainless steels are often considered candidate materials for use in hydrogen-containing environments because of their low hydrogen embrittlement susceptibility. In this study, the fatigue crack growth behavior of the solution-annealed and cold-rolled 301, 304L, and 310S austenitic stainless steels was characterized in 0.2 MPa gaseous hydrogen to evaluate the hydrogen-assisted fatigue crack growth and correlate the fatigue crack growth rates with the fracture feature or fracture surface roughness. Regardless of the testing conditions, higher fracture surface roughness could be obtained in a higher stress intensity factor (∆K range and for the counterpart cold-rolled specimen in hydrogen. The accelerated fatigue crack growth of 301 and 304L in hydrogen was accompanied by high fracture surface roughness and was associated with strain-induced martensitic transformation in the plastic zone ahead of the fatigue crack tip.

Dielectrophoretic separation of gaseous isotopes

International Nuclear Information System (INIS)

McConnell, D.B.

1975-01-01

Gaseous isotopes are separated from a mixture in a vertically elongated chamber by subjecting the mixture to a nonuniform transverse electric field. Dielectrophoretic separation of the isotopes is effected, producing a transverse temperature gradient in the chamber, thereby enhancing the separation by convective countercurrent flow. In the example given, the process and apparatus are applied to the production of heavy water from steam

Are climate warming and enhanced atmospheric deposition of sulfur and nitrogen threatening tufa landscapes in Jiuzhaigou National Nature Reserve, Sichuan, China?

Science.gov (United States)

Qiao, Xue; Du, Jie; Lugli, Stefano; Ren, Jinhai; Xiao, Weiyang; Chen, Pan; Tang, Ya

2016-08-15

Massive deposition of calcium carbonate in ambient temperature waters (tufa) can form magnificent tufa landscapes, many of which are designated as protected areas. However, tufa landscapes in many areas are threatened by both local anthropogenic activities and climate change. This study, for the first time, posed the question whether the tufa landscape degradation (characterized by tufa degradation and increased biomass of green algae) in Jiuzhaigou National Nature Reserve of China is partially caused by regional air pollution and climate warming. The results indicate that wet deposition (including rain and snow) polluted by anthropogenic SO2, NOx, and NH3 emissions dissolves exposed tufa and may considerably reduce tufa deposition rate and even cause tufa dissolution within shallow waters. These effects of wet deposition on tufa enhanced as pH of wet deposition decreased from 8.01 to 5.06. Annual Volume Weighted Mean concentration of reactive nitrogen (including NH4(+) and NO3(-)) in wet deposition (26.1μmolL(-1)) was 1.8 times of the corresponding value of runoff (14.8μmolL(-1)) and exceeded China's national standard of total nitrogen in runoff for nature reserves (14.3μmolL(-1)), indicating a direct nitrogen fertilization effect of wet deposition on green algae. As water temperature is the major limiting factor of algal growth in Jiuzhaigou and temperature in the top layer (0-5cm) of runoff (depthclimate warming in this region would favor algal growth. In sum, this study suggests that climate warming and enhanced sulfur and nitrogen deposition have contributed to the current degradation of tufa landscape in Jiuzhaigou, but in order to quantify the contributions, further studies are needed, as many other anthropogenic and natural processes also influence tufa landscape evolution. Copyright © 2016 Elsevier B.V. All rights reserved.

The role of nitrogen and phosphorus in regulating Phormidium sp. (cyanobacteria) growth and anatoxin production.

Science.gov (United States)

Heath, Mark; Wood, Susie A; Young, Roger G; Ryan, Ken G

2016-03-01

Benthic proliferations of the cyanobacteria Phormidium can cover many kilometres of riverbed. Phormidium can produce neurotoxic anatoxins and ingestion of benthic mats has resulted in numerous animal poisonings in the last decade. Despite this, there is a poor understanding of the environmental factors regulating growth and anatoxin production. In this study, the effects of nitrogen and phosphorus on the growth of two Phormidium strains (anatoxin-producing and non-anatoxin-producing) were examined in batch monocultures. Cell concentrations were significantly reduced under reduced nitrogen (ca. production. Cellular anatoxin concentrations were lowest (169 fg cell(-1)) under the high-nitrogen and high-phosphorus treatment. This supports the growth-differentiation balance hypothesis that suggests actively dividing and expanding cells are less likely to produce secondary-metabolites. Anatoxin quota was highest (>407 fg cell(-1)) in the reduced phosphorus treatments, possibly suggesting that it is produced as a stress response to growth limiting conditions. In all treatments there was a 4-5-fold increase in anatoxin quota in the lag growth phase, possibly indicating it may provide a physiological benefit during initial substrate colonization. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Nitrogen-oxy compounds formation in moist - N2 gaseous systems

International Nuclear Information System (INIS)

Dey, G.R.; Das, Tomi Nath

2015-01-01

In any high ionizing radiation zone continuous generation of nitrogen compounds such as NO 2 , NO 2 - and NO 3 - in aqueous and gas phase is a normal phenomena. Their formation mechanisms, and the control processes still pose a challenge with reference to the resulting corrosive environment generated, and it's effect on various structural materials used in nuclear industry. The source(s) of nitrogen for these products are mainly air which ingresses into the system, and/or nitrogen compounds such as ammonia, hydrazine, volatile amines used in different parts of the nuclear power plants to control pH and scavenge dissolved oxygen in coolant/moderator systems. Under high radiation environment their subsequent chemistry leads to the formation of various N-O compounds. With the objective to elucidate such reaction mechanisms, we studied and compared the chemistry of nitrogen in water and moist-nitrogen systems under the complimentary initiation techniques of cold plasma, wherein free electrons in eV energy range initiate the radical induced chemistry. In the gas phase, cold plasma produced NO and NO 2 which were confirmed on-line by respective absorbance measurement at 204, 214.5, 226 and 400 nm, while NO 2 - was analyzed as additional product after wet-chemical sampling in sulphanalic acid (0.5%) and N (1-naphthyl) ethylene diamine dihydrochloride (0.1%) mixed solution followed by absorbance measurement at 540 nm. This work was explored in three different systems: (i) N 2 from commercial high purity N 2 gas cylinder, (ii) N 2 from such source pretreated with activated silica gel (to reduce/minimize moisture concentration further) and (iii) N 2 bubbled through water (saturated moisture in N 2 system). The observed concentration of NO 2 - was found to be higher in moisture saturated N 2 system. In this presentation a brief summary of the results on various aspect of the formation of different N-O compounds during radiolysis of aqueous systems and gas phase cold

Nitrogen side-dress as a strategy to reduce defoliation demages at different growth stages of maize

Directory of Open Access Journals (Sweden)

Luis Sangoi

2014-02-01

Full Text Available Nitrogen can mitigate damages caused by leaf area reduction due to its influence on cell division. This work was carried out aiming to evaluate the efficiency of side-dressing different rates of nitrogen as a management strategy to maize stem defoliation at different growth stages. The experiment was set in Lages, during the 2008/2009 and 2009/2010 growing seasons. The experimental design was a randomized block with split plots. Three defoliation times were tested in the main plot: eight expanded leaves (V8, fifteen expanded leaves (V15 and tasseling (VT, plus a control without defoliation. Four nitrogen rates were assessed in the split-plots: 0, 50, 100 and 200 kg ha-1 of N. Nitrogen was side-dressed at the defoliation day of each growth stage and at V8 in the control. Defoliations performed at V8 did not reduce grain yield, in comparison to the control, regardless of N rate. Side-dressing N rates at V15 increased grain yield, mitigating damages caused by defoliation. Defoliation carried out at VT promoted great grain yield reduction that could not be alleviated with subsequent nitrogen fertilization. The success of nitrogen side-dress as a strategy to minimize maize grain yield losses caused by defoliation depends on the growth stage leaf area reduction occurs.

Nitrogen-fixing trees inhibit growth of regenerating Costa Rican rainforests.

Science.gov (United States)

Taylor, Benton N; Chazdon, Robin L; Bachelot, Benedicte; Menge, Duncan N L

2017-08-15

More than half of the world's tropical forests are currently recovering from human land use, and this regenerating biomass now represents the largest carbon (C)-capturing potential on Earth. How quickly these forests regenerate is now a central concern for both conservation and global climate-modeling efforts. Symbiotic nitrogen-fixing trees are thought to provide much of the nitrogen (N) required to fuel tropical secondary regrowth and therefore to drive the rate of forest regeneration, yet we have a poor understanding of how these N fixers influence the trees around them. Do they promote forest growth, as expected if the new N they fix facilitates neighboring trees? Or do they suppress growth, as expected if competitive inhibition of their neighbors is strong? Using 17 consecutive years of data from tropical rainforest plots in Costa Rica that range from 10 y since abandonment to old-growth forest, we assessed how N fixers influenced the growth of forest stands and the demographic rates of neighboring trees. Surprisingly, we found no evidence that N fixers facilitate biomass regeneration in these forests. At the hectare scale, plots with more N-fixing trees grew slower. At the individual scale, N fixers inhibited their neighbors even more strongly than did nonfixing trees. These results provide strong evidence that N-fixing trees do not always serve the facilitative role to neighboring trees during tropical forest regeneration that is expected given their N inputs into these systems.

Effect of Nitrogen Fertilizer on Weeds Growth and Emergence and Yield and Yield Components of Corn (Zea mays L.

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M. Gholamshahi

2017-01-01

Full Text Available Introduction: Corn is one of the important crops of poaceae family which has important role in supplying food for human societies. Corn is third food crop in world and it has high potential compare to other crops because of its C4 photosynthetic pathway. In addition, corn is a strong and fast growing plant but it is sensitive to competition with weeds. According studies, there are 25 to 30 problematic weeds in corn farms which they include annual and perennial species. Annual weeds life cycle is similar to corn life cycle, there for the most problem of weeds in corn is summer annual weeds. Damage of weeds is different and it depends on weeds density, species composition, time of emergence, crop variety and other factors. While non control of weeds depending on those density and Variety, corn yeild may be decrease of 15 to 90 percent. Weeds which germinate in a short time can compete with crop on light, water and nutrition sources. Most of the weeds show better reaction to fertilizers compare with crops. This subject is due to weeds ability to nutrition absorption and aggregation and their high performances. Most of the weeds species are more responsive than crops to application of nitrogen fertilizer. Furthermore, the growth of most of the weed species increases with increasing nitrogen. Therefore, the increase of nitrogen in farming systems can have impacts on weeds and crops competitiveness. However, weeds compete with crop about using light, nutrient, water and soil space and the result of this competition is yield losses. Moreover, nitrogen is necessary to increase yield and nitrogen fertilizer enhances corn competitiveness, especially early in the season due to the slow growth of the plant and is necessary to achieve optimal performance. Excessive of nitrogen fertilizer during the growing season is benefit for weeds. Therefore, in order to study the effects of nitrogen fertilizer in combination with weeds management on yield and yield

Nitrogen controlled iron catalyst phase during carbon nanotube growth

Energy Technology Data Exchange (ETDEWEB)

Bayer, Bernhard C., E-mail: bernhard.bayer@univie.ac.at [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Faculty of Physics, University of Vienna, A-1090 Vienna (Austria); Baehtz, Carsten [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, D-01314 Dresden (Germany); Kidambi, Piran R.; Weatherup, Robert S.; Caneva, Sabina; Cabrero-Vilatela, Andrea; Hofmann, Stephan [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Mangler, Clemens; Kotakoski, Jani; Meyer, Jannik C. [Faculty of Physics, University of Vienna, A-1090 Vienna (Austria); Goddard, Caroline J. L. [Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB3 0FS (United Kingdom)

2014-10-06

Close control over the active catalyst phase and hence carbon nanotube structure remains challenging in catalytic chemical vapor deposition since multiple competing active catalyst phases typically co-exist under realistic synthesis conditions. Here, using in-situ X-ray diffractometry, we show that the phase of supported iron catalyst particles can be reliably controlled via the addition of NH{sub 3} during nanotube synthesis. Unlike polydisperse catalyst phase mixtures during H{sub 2} diluted nanotube growth, nitrogen addition controllably leads to phase-pure γ-Fe during pre-treatment and to phase-pure Fe{sub 3}C during growth. We rationalize these findings in the context of ternary Fe-C-N phase diagram calculations and, thus, highlight the use of pre-treatment- and add-gases as a key parameter towards controlled carbon nanotube growth.

Improved cell viability and hydroxyapatite growth on nitrogen ion-implanted surfaces

Science.gov (United States)

Shafique, Muhammad Ahsan; Murtaza, G.; Saadat, Shahzad; Uddin, Muhammad K. H.; Ahmad, Riaz

2017-08-01

Stainless steel 306 is implanted with various doses of nitrogen ions using a 2 MV pelletron accelerator for the improvement of its surface biomedical properties. Raman spectroscopy reveals incubation of hydroxyapatite (HA) on all the samples and it is found that the growth of incubated HA is greater in higher ion dose samples. SEM profiles depict uniform growth and greater spread of HA with higher ion implantation. Human oral fibroblast response is also found consistent with Raman spectroscopy and SEM results; the cell viability is found maximum in samples treated with the highest (more than 300%) dose. XRD profiles signified greater peak intensity of HA with ion implantation; a contact angle study revealed hydrophilic behavior of all the samples but the treated samples were found to be lesser hydrophilic compared to the control samples. Nitrogen implantation yields greater bioactivity, improved surface affinity for HA incubation and improved hardness of the surface.

Permafrost carbon−climate feedback is sensitive to deep soil carbon decomposability but not deep soil nitrogen dynamics

Science.gov (United States)

Koven, Charles D.; Lawrence, David M.; Riley, William J.

2015-01-01

Permafrost soils contain enormous amounts of organic carbon whose stability is contingent on remaining frozen. With future warming, these soils may release carbon to the atmosphere and act as a positive feedback to climate change. Significant uncertainty remains on the postthaw carbon dynamics of permafrost-affected ecosystems, in particular since most of the carbon resides at depth where decomposition dynamics may differ from surface soils, and since nitrogen mineralized by decomposition may enhance plant growth. Here we show, using a carbon−nitrogen model that includes permafrost processes forced in an unmitigated warming scenario, that the future carbon balance of the permafrost region is highly sensitive to the decomposability of deeper carbon, with the net balance ranging from 21 Pg C to 164 Pg C losses by 2300. Increased soil nitrogen mineralization reduces nutrient limitations, but the impact of deep nitrogen on the carbon budget is small due to enhanced nitrogen availability from warming surface soils and seasonal asynchrony between deeper nitrogen availability and plant nitrogen demands. Although nitrogen dynamics are highly uncertain, the future carbon balance of this region is projected to hinge more on the rate and extent of permafrost thaw and soil decomposition than on enhanced nitrogen availability for vegetation growth resulting from permafrost thaw. PMID:25775603

Measurements of gaseous multiplication coefficient in pure isobutane; Medidas do coeficiente de multiplicacao gasosa no isobutano puro

Energy Technology Data Exchange (ETDEWEB)

Lima, Iara Batista de

2010-07-01

In this work it is presented measurements of gaseous multiplication coefficient ({alpha}) in pure isobutane obtained with a parallel plate chamber, protected against discharges by one electrode (anode) of high resistivity glass ({rho} = 2 x 10{sup 12}{Omega}.cm). The method applied was the Pulsed Townsend, where the primary ionization is produced through the incidence of a nitrogen laser beam onto a metallic electrode (cathode). The electric currents measured with the chamber operating in both ionization and avalanche regimes were used to calculate the gaseous multiplication coefficient by the solution of the Townsend equation for uniform electric fields. The validation of the technique was provided by the measurements of gaseous multiplication coefficient in pure nitrogen, a widely studied gas, which has well-established data in literature. The {alpha} coefficients in isobutane were measured as a function of the reduced electric field in the range of 139Td up to 208Td. The obtained values were compared with those simulated by Imonte software (version 4.5) and the only experimental results available in the literature, recently obtained in our group. This comparison showed that the results are concordant within the experimental errors. (author)

Influence of abscisic acid on growth, biomass and lipid yield of Scenedesmus quadricauda under nitrogen starved condition.

Science.gov (United States)

Sulochana, Sujitha Balakrishnan; Arumugam, Muthu

2016-08-01

Scenedesmus quadricauda, accumulated more lipid but with a drastic reduction in biomass yield during nitrogen starvation. Abscisic acid (ABA) being a stress responsible hormone, its effect on growth and biomass with sustainable lipid yield during nitrogen depletion was studied. The result revealed that the ABA level shoots up at 24h (27.21pmol/L) during the onset of nitrogen starvation followed by a sharp decline. The external supplemented ABA showed a positive effect on growth pattern (38×10(6)cells/ml) at a lower concentration. The dry biomass yield is also increasing up to 2.1 fold compared to nitrogen deficient S. quadricauda. The lipid content sustains in 1 and 2μM concentration of ABA under nitrogen-deficient condition. The fatty acid composition of ABA treated S. quadricauda cultures with respect to nitrogen-starved cells showed 11.17% increment in saturated fatty acid content, the desired lipid composition for biofuel application. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impacts of Plant Growth-Promoting Rhizobacteria-based Biostimulants on Wheat Growth under Greenhouse and Field Conditions

OpenAIRE

Nguyen, Minh; Ongena, Marc; Colinet, Gilles; Vandenbol, Micheline; Spaepen, Stijn; Bodson, Bernard; Jijakli, Haissam; du Jardin, Patrick; Delaplace, Pierre

2015-01-01

Plant Growth-Promoting Rhizobacteria (PGPR) are one of the main biostimulant classes due to their capacity of stimulating root growth and enhancing soil mineral availability, hence increasing nutrient use efficiency in crops. The aim of this study is to screen commercially PGPR-containing products to enhance wheat growth and yield in combination with an optimized nitrogen (N) fertilizer application scheme. This could lead to a significant reduction of N fertilizer application without affectin...

Gaseous nebulae

International Nuclear Information System (INIS)

Williams, R.E.

1976-01-01

Gaseous nebulae are large, tenuous clouds of ionized gas that are associated with hot stars and that emit visible light because of the energy that they receive from the ultraviolet radiation of the stars. Examples include H II regions, planetary nebulae, and nova/supernova remnants. The emphasis is on the physical processes that occur in gaseous nebulae as opposed to a study of the objects themselves. The introduction discusses thermodynamic vs. steady-state equilibrium and excitation conditions in a dilute radiation field. Subsequent sections take up important atomic processes in gaseous nebulae (particle--particle collision rates, radiative interaction rates, cross sections), the ionization equilibrium (sizes of H II regions, ionization of the heavier elements), kinetic temperature and energy balance (heating of the electrons, cooling of the electrons), and the spectra of gaseous nebulae (line fluxes in nebulae). 7 figures, 5 tables

Density effects in heavy ion charge-exchange processes in gaseous and solid targets

International Nuclear Information System (INIS)

Teplova, Ya.A.; Dmitriev, I.S.; Belkova, Yu.A.

2000-01-01

Experimental results on the pre-equilibrium and equilibrium charge distributions in celluloid films for incident Be, B, C, N, O ions are analyzed in order to obtain charge-exchange cross-sections. The determined 'effective' cross-sections of electron capture and loss in celluloid together with earlier measured analogous cross-sections in nitrogen allow us to calculate charge fractions F i (t) depending on the target thickness in solid (celluloid) and gaseous (nitrogen) matter. The absolute values and the ratios A cap =σ g i,i-1 /σ s i,i-1 and A loss =σ g i-1,i /σ s i-1,i of electron capture and loss cross-sections in {s} solids (celluloid, carbon) and {g} gases (nitrogen) are under consideration

Changes in Growth and Oil Yield Indices of Rapeseed (Brassica napus L., cv. Hyola 401 in Different Concentrations andTimes of Application of Supplementary Nitrogen Fertilizer

Directory of Open Access Journals (Sweden)

P. Tousi Kehal

2013-03-01

Full Text Available In order to investigate the effect of concentration and time of supplementary nitrogen fertilizer spray on growth indices of rapeseed (cv. Hyola 401, a field experiment was conducted at Rice Research Institute of Iran as a randomized complete blocks design with 16 treatments and 3 replications in 2008-2009. The treatments included concentration of nitrogen fertilizer (urea at two levels (5 and 10 ppm in seven levels of application time:1 spraying at 6-8- leaf stage, 2 beginning of stem elongation, 3 prior to flowering, 4 at 6-8- leaf stage + beginning of stem elongation, 5 at 6-8- leaf + prior to flowering, 6 beginning of stem elongation+ prior to flowering, and 7 at 6-8- leaf + beginning of stem elongation+ prior to flowering, which were compared with two control treatments (no fertilizer nitrogen and conventional soil fertilization. Results showed that significant difference was observed between spray treatments including concentration and times of nitrogen application, between controls and between controls with spray treatments, of grain and oil yield, crop growth rate (CGR, leaf area index (LAI and leaf area duration (LAD. Application of nitrogen (10 ppm at the beginning of stem elongation+ prior to flowering stages produced maximum grain yield (4221.7 kg/ha and oil yield (1771.1 kg/ha. Spray treatments produced maximum oil yield index (15.3% compared to controls. Maximum LAI (6.9 and 5.6 respectively, CGR (15.2 and 14.3 g/m2.10 GDD, respectively and LAD (1204 and 1029 cm2/10 GDD, respectively were also obtained from spray application of nitrogen (10 ppm at the beginning of stem elongation+ prior to flowering stages and at 6-8-leaf stage + beginning of stem elongation + prior to flowering. According to the results of the present investigation, it seems that foliar application of supplementary nitrogen fertilizer at the end growth stages (beginning of stem elongation and prior to flowering of rapeseed plants may help to enhance growth indices

Nitrogen-doping effects on the growth, structure and electrical performance of carbon nanotubes obtained by spray pyrolysis method

Energy Technology Data Exchange (ETDEWEB)

Ionescu, Mihnea Ioan; Zhang Yong; Li Ruying [Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON N6A 5B9 (Canada); Abou-Rachid, Hakima [Defense Research and Development Canada - Valcartier, 2459 Boulevard PieXI Nord, Quebec, QC G3J 1X5 (Canada); Sun Xueliang, E-mail: xsun@eng.uwo.ca [Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON N6A 5B9 (Canada)

2012-03-01

Vertically aligned nitrogen-doped carbon nanotubes (CNTs) with modulated nitrogen content have been synthesized in a large scale by using spray pyrolysis chemical vapor deposition technique. The effects of nitrogen doping on the growth, structure and electrical performance of carbon nanotubes have been systematically examined. Field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman techniques have been employed to characterize the morphology, composition, and vibrational properties of nanotubes. The results indicate that the nitrogen incorporation significantly influences the growth rate, morphology, size and structure of nanotubes. Electrical measurement investigation of the nanotubes indicates that the change in electrical resistance increases with temperature and pressure as the nitrogen concentration increases inside the tubes. This work presents a versatile, safe, and easy way to scale up route of growing carbon nanotubes with controlled nitrogen content and modulated structure, and may provide an insight in developing various nitrogen-doped carbon-based nanodevices.

Electron spin contrast of Purcell-enhanced nitrogen-vacancy ensembles in nanodiamonds

Science.gov (United States)

Bogdanov, S.; Shalaginov, M. Y.; Akimov, A.; Lagutchev, A. S.; Kapitanova, P.; Liu, J.; Woods, D.; Ferrera, M.; Belov, P.; Irudayaraj, J.; Boltasseva, A.; Shalaev, V. M.

2017-07-01

Nitrogen-vacancy centers in diamond allow for coherent spin-state manipulation at room temperature, which could bring dramatic advances to nanoscale sensing and quantum information technology. We introduce a method for the optical measurement of the spin contrast in dense nitrogen-vacancy (NV) ensembles. This method brings insight into the interplay between the spin contrast and fluorescence lifetime. We show that for improving the spin readout sensitivity in NV ensembles, one should aim at modifying the far-field radiation pattern rather than enhancing the emission rate.

Subtle Gardeners: Inland Predators Enrich Local Topsoils and Enhance Plant Growth.

Science.gov (United States)

Fedriani, José M; Garrote, Pedro José; Delgado, María del Mar; Penteriani, Vincenzo

2015-01-01

Inland vertebrate predators could enrich of nutrients the local top soils in the area surrounding their nests and dens by depositing faeces, urine, and prey remains and, thus, alter the dynamics of plant populations. Surprisingly, and in contrast with convincing evidence from coastal habitats, whether and how this phenomenon occurs in inland habitats is largely uncertain even though these habitats represent a major fraction of the earth's surface. We investigated during two consecutive breeding seasons the potential enrichment of the top-soils associated with inland ground-nesting eagle owls Bubo bubo, as well as its possible consequences in the growth of two common annual grasses in southern Spain. Top-soils associated with owl nests differed strongly and significantly from control top-soils in chemical parameters, mainly fertility-related properties. Specifically, levels of available phosphorus, total nitrogen, organic matter, and available potassium were 49.1, 5.6, 3.1, and 2.7 times higher, respectively, in top-soils associated with owl nests as compared to control top-soils. Germination experiments in chambers indicated that nutrient enrichment by nesting owls enhanced seedling growth in both annual grasses (Phalaris canariensis and Avena sativa), with seedling size being 1.4-1.3 times higher in owl nest top-soils than in control top-soils. Our experimental study revealed that pervasive inland, predatory birds can profoundly enrich the topsoil around their nests and, thus, potentially enhance local vegetation growth. Because diverse inland vertebrate predators are widespread in most habitats they have a strong potential to enhance spatial heterogeneity, impinge on plant communities, and exert an overlooked effect on primary productivity worldwide.

Subtle Gardeners: Inland Predators Enrich Local Topsoils and Enhance Plant Growth.

Directory of Open Access Journals (Sweden)

José M Fedriani

Full Text Available Inland vertebrate predators could enrich of nutrients the local top soils in the area surrounding their nests and dens by depositing faeces, urine, and prey remains and, thus, alter the dynamics of plant populations. Surprisingly, and in contrast with convincing evidence from coastal habitats, whether and how this phenomenon occurs in inland habitats is largely uncertain even though these habitats represent a major fraction of the earth's surface. We investigated during two consecutive breeding seasons the potential enrichment of the top-soils associated with inland ground-nesting eagle owls Bubo bubo, as well as its possible consequences in the growth of two common annual grasses in southern Spain. Top-soils associated with owl nests differed strongly and significantly from control top-soils in chemical parameters, mainly fertility-related properties. Specifically, levels of available phosphorus, total nitrogen, organic matter, and available potassium were 49.1, 5.6, 3.1, and 2.7 times higher, respectively, in top-soils associated with owl nests as compared to control top-soils. Germination experiments in chambers indicated that nutrient enrichment by nesting owls enhanced seedling growth in both annual grasses (Phalaris canariensis and Avena sativa, with seedling size being 1.4-1.3 times higher in owl nest top-soils than in control top-soils. Our experimental study revealed that pervasive inland, predatory birds can profoundly enrich the topsoil around their nests and, thus, potentially enhance local vegetation growth. Because diverse inland vertebrate predators are widespread in most habitats they have a strong potential to enhance spatial heterogeneity, impinge on plant communities, and exert an overlooked effect on primary productivity worldwide.

A Case Study of Nitrogen Saturation in Western U.S. Forests

Directory of Open Access Journals (Sweden)

Mark E. Fenn

2001-01-01

Full Text Available Virtually complete nitrification of the available ammonium in soil and nitrification activity in the forest floor are important factors predisposing forests in the San Bernardino Mountains of southern California to nitrogen (N saturation. As a result, inorganic N in the soil solution is dominated by nitrate. High nitrification rates also generate elevated nitric oxide (NO emissions from soil. High-base cation saturation of these soils means that soil calcium depletion or effects associated with soil acidification are not an immediate risk for forest health as has been postulated for mesic forests in the eastern U.S. Physiological disturbance (e.g., altered carbon [C] cycling, reduced fine root biomass, premature needle abscission of ozone-sensitive ponderosa pine trees exposed to high N deposition and high ozone levels appear to be the greater threat to forest sustainability. However, N deposition appears to offset the aboveground growth depression effects of ozone exposure. High nitrification activity reported for many western ecosystems suggests that with chronic N inputs these systems are prone to N saturation and hydrologic and gaseous losses of N. High runoff during the winter wet season in California forests under a Mediterranean climate may further predispose these watersheds to high nitrate leachate losses. After 4 years of N fertilization at a severely N saturated site in the San Bernardino Mountains, bole growth unexpectedly increased. Reduced C allocation below- ground at this site, presumably in response to ozone or N or both pollutants, may enhance the bole growth response to added N.

Arabidopsis Phosphatidic Acid Phosphohydrolases Are Essential for Growth under Nitrogen-Depleted Conditions

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Yushi Yoshitake

2017-10-01

Full Text Available The Arabidopsis homologs of mammalian lipin, PAH1 and PAH2, are cytosolic phosphatidic acid phosphohydrolases that are involved in phospholipid biosynthesis and are essential for growth under phosphate starvation. Here, pah1 pah2 double-knockout mutants were found to be hypersensitive to nitrogen (N starvation, whereas transgenic plants overexpressing PAH1 or PAH2 in the pah1 pah2 mutant background showed a similar growth phenotype as compared with wild type (WT under N starvation. The chlorophyll content of pah1 pah2 was significantly lower than that of WT, whereas the chlorophyll content and photosynthetic activity of the transgenic plants were significantly higher than those of WT under N-depleted conditions. Membrane glycerolipid composition of the pah1 pah2 mutants showed a significant decrease in the mole percent of chloroplast lipids to other phospholipids, whereas membrane lipid composition did not differ between transgenic plants and WT plants. Pulse-chase labeling experiments using plants grown under N-depleted conditions showed that, in pah1 pah2 plants, the labeling percent of chloroplast lipids such as phosphatidylglycerol and monogalactosyldiacylglycerol in the total glycerolipids was significantly lower than in WT. Moreover, N starvation-induced degradation of chloroplast structure was enhanced in pah1 pah2 mutants, and the membrane structure was recovered by complementation with PAH1. Thus, PAH is involved in maintaining chloroplast membrane structure and is required for growth under N-depleted conditions.

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

Growth-promoting Sphingomonas paucimobilis ZJSH1 associated with Dendrobium officinale through phytohormone production and nitrogen fixation

Science.gov (United States)

Yang, Suijuan; Zhang, Xinghai; Cao, Zhaoyun; Zhao, Kaipeng; Wang, Sai; Chen, Mingxue; Hu, Xiufang

2014-01-01

Growth-promoting Sphingomonas paucimobilis ZJSH1, associated with Dendrobium officinale, a traditional Chinese medicinal plant, was characterized. At 90 days post-inoculation, strain ZJSH1 significantly promoted the growth of D. officinale seedlings, with increases of stems by 8.6% and fresh weight by 7.5%. Interestingly, the polysaccharide content extracted from the inoculated seedlings was 0.6% higher than that of the control. Similar growth promotion was observed with the transplants inoculated with strain ZJSH1. The mechanism of growth promotion was attributed to a combination of phytohormones and nitrogen fixation. Strain ZJSH1 was found using the Kjeldahl method to have a nitrogen fixation activity of 1.15 mg l−1, which was confirmed by sequencing of the nifH gene. Using high-performance liquid chromatography-mass spectrometry, strain ZJSH1 was found to produce various phytohormones, including salicylic acid (SA), indole-3-acetic acid (IAA), Zeatin and abscisic acid (ABA). The growth curve showed that strain ZJSH1 grew well in the seedlings, especially in the roots. Accordingly, much higher contents of SA, ABA, IAA and c-ZR were detected in the inoculated seedlings, which may play roles as both phytohormones and ‘Systemic Acquired Resistance’ drivers. Nitrogen fixation and secretion of plant growth regulators (SA, IAA, Zeatin and ABA) endow S. paucimobilis ZJSH1 with growth-promoting properties, which provides a potential for application in the commercial growth of D. officinale. PMID:25142808

Evaluation of the influence of nitrogen fixing, phosphate solubilizing ...

African Journals Online (AJOL)

Three biofertilizers nitrobein, phosphorein, and potash, containing nitrogen fixing, phosphate solubilizing, and potash mobilizing microorganisms, respectively were studied in peanut (Arachis hypogea L.) and sunflower (Helianthus annuus L.). Amendment with each of these biofertilizers enhanced different growth ...

Response of Quercus velutina growth and water use efficiency to climate variability and nitrogen fertilization in a temperate deciduous forest in the northeastern USA.

Science.gov (United States)

Jennings, Katie A; Guerrieri, Rossella; Vadeboncoeur, Matthew A; Asbjornsen, Heidi

2016-04-01

Nitrogen (N) deposition and changing climate patterns in the northeastern USA can influence forest productivity through effects on plant nutrient relations and water use. This study evaluates the combined effects of N fertilization, climate and rising atmospheric CO2on tree growth and ecophysiology in a temperate deciduous forest. Tree ring widths and stable carbon (δ(13)C) and oxygen (δ(18)O) isotopes were used to assess tree growth (basal area increment, BAI) and intrinsic water use efficiency (iWUE) ofQuercus velutinaLamb., the dominant tree species in a 20+ year N fertilization experiment at Harvard Forest (MA, USA). We found that fertilized trees exhibited a pronounced and sustained growth enhancement relative to control trees, with the low- and high-N treatments responding similarly. All treatments exhibited improved iWUE over the study period (1984-2011). Intrinsic water use efficiency trends in the control trees were primarily driven by changes in stomatal conductance, while a stimulation in photosynthesis, supported by an increase in foliar %N, contributed to enhancing iWUE in fertilized trees. All treatments were predominantly influenced by growing season vapor pressure deficit (VPD), with BAI responding most strongly to early season VPD and iWUE responding most strongly to late season VPD. Nitrogen fertilization increasedQ. velutinasensitivity to July temperature and precipitation. Combined, these results suggest that ambient N deposition in N-limited northeastern US forests has enhanced tree growth over the past 30 years, while rising ambient CO2has improved iWUE, with N fertilization and CO2having synergistic effects on iWUE. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Manipulating vineyard nitrogen on a saline site: 1. Effect of nitrogen on growth, grape yield and nutrients of Vitis vinifera L. cv Shiraz.

Science.gov (United States)

Bell, Sally-Jean; Francis, I Leigh

2013-08-15

With increased prevalence of saline irrigation water applied to vines worldwide, the issue of appropriate nitrogen management is of concern. Different rates of nitrogen per vine as urea were applied to Shiraz vines on own roots over four seasons in a low-rainfall, saline growing environment. Application of nitrogen in the vineyard early in the season not only altered the vine nitrogen status but also increased some other elements in the petioles, notably chloride and sodium but also manganese and magnesium. In contrast, nitrogen application decreased petiole phosphorus. In comparison with the majority of nitrogen studies on non-saline sites, nitrogen-induced growth responses were restricted under the saline conditions in this study. While some changes in canopy density in response to nitrogen were observed, this did not affect light interception in the fruit zone. Yield responses were varied and could be related to the nutritional conditions under which bud development and flowering took place. This study demonstrated that current best practice guidelines, in terms of rate of nitrogen applied, for correcting a nitrogen deficiency on a non-saline site may not be appropriate for saline sites and that application of nitrogen can increase the potential for salt toxicity in vines. © 2013 Society of Chemical Industry.

Enhanced nitrogen deposition over China

Energy Technology Data Exchange (ETDEWEB)

Liu, Xuejun; Zhang, Ying; Han, Wenxuan; Tang, Aohan; Shen, Jianlin; Cui, Zhenling; Christie, Peter; Zhang, Fusuo [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Vitousek, Peter [Department of Biology, Stanford University, Stanford, California 94305 (United States); Erisman, Jan Willem [VU University Amsterdam, 1081 HV Amsterdam (Netherlands); Goulding, Keith [The Sustainable Soils and Grassland Systems Department, Rothamsted Research, Harpenden AL5 2JQ (United Kingdom); Fangmeier, Andreas [Institute of Landscape and Plant Ecology, University of Hohenheim, 70593 Stuttgart (Germany)

2013-02-28

China is experiencing intense air pollution caused in large part by anthropogenic emissions of reactive nitrogen. These emissions result in the deposition of atmospheric nitrogen (N) in terrestrial and aquatic ecosystems, with implications for human and ecosystem health, greenhouse gas balances and biological diversity. However, information on the magnitude and environmental impact of N deposition in China is limited. Here we use nationwide data sets on bulk N deposition, plant foliar N and crop N uptake (from long-term unfertilized soils) to evaluate N deposition dynamics and their effect on ecosystems across China between 1980 and 2010. We find that the average annual bulk deposition of N increased by approximately 8 kilograms of nitrogen per hectare (P < 0.001) between the 1980s (13.2 kilograms of nitrogen per hectare) and the 2000s (21.1 kilograms of nitrogen per hectare). Nitrogen deposition rates in the industrialized and agriculturally intensified regions of China are as high as the peak levels of deposition in northwestern Europe in the 1980s, before the introduction of mitigation measures. Nitrogen from ammonium (NH4+) is the dominant form of N in bulk deposition, but the rate of increase is largest for deposition of N from nitrate (NO3-), in agreement with decreased ratios of NH3 to NOx emissions since 1980. We also find that the impact of N deposition on Chinese ecosystems includes significantly increased plant foliar N concentrations in natural and semi-natural (that is, non-agricultural) ecosystems and increased crop N uptake from long-term-unfertilized croplands. China and other economies are facing a continuing challenge to reduce emissions of reactive nitrogen, N deposition and their negative effects on human health and the environment.

Deciphering the Principles of Bacterial Nitrogen Dietary Preferences: a Strategy for Nutrient Containment.

Science.gov (United States)

Wang, Jilong; Yan, Dalai; Dixon, Ray; Wang, Yi-Ping

2016-07-19

A fundamental question in microbial physiology concerns why organisms prefer certain nutrients to others. For example, among different nitrogen sources, ammonium is the preferred nitrogen source, supporting fast growth, whereas alternative nitrogen sources, such as certain amino acids, are considered to be poor nitrogen sources, supporting much slower exponential growth. However, the physiological/regulatory logic behind such nitrogen dietary choices remains elusive. In this study, by engineering Escherichia coli, we switched the dietary preferences toward amino acids, with growth rates equivalent to that of the wild-type strain grown on ammonia. However, when the engineered strain was cultured together with wild-type E. coli, this growth advantage was diminished as a consequence of ammonium leakage from the transport-and-catabolism (TC)-enhanced (TCE) cells, which are preferentially utilized by wild-type bacteria. Our results reveal that the nitrogen regulatory (Ntr) system fine tunes the expression of amino acid transport and catabolism components to match the flux through the ammonia assimilation pathway such that essential nutrients are retained, but, as a consequence, the fast growth rate on amino acids is sacrificed. Bacteria exhibit different growth rates under various nutrient conditions. These environmentally related behaviors reflect the coordination between metabolism and the underlying regulatory networks. In the present study, we investigated the intertwined nitrogen metabolic and nitrogen regulatory systems to understand the growth differences between rich and poor nitrogen sources. Although maximal growth rate is considered to be evolutionarily advantageous for bacteria (as remarked by François Jacob, who said that the "dream" of every cell is to become two cells), we showed that negative-feedback loops in the regulatory system inhibit growth rates on amino acids. We demonstrated that in the absence of regulatory feedback, amino acids are capable

Unravelling chemical priming machinery in plants: the role of reactive oxygen-nitrogen-sulfur species in abiotic stress tolerance enhancement.

Science.gov (United States)

Antoniou, Chrystalla; Savvides, Andreas; Christou, Anastasis; Fotopoulos, Vasileios

2016-10-01

Abiotic stresses severely limit crop yield and their detrimental effects are aggravated by climate change. Chemical priming is an emerging field in crop stress management. The exogenous application of specific chemical agents before stress events results in tolerance enhancement and reduction of stress impacts on plant physiology and growth. However, the molecular mechanisms underlying the remarkable effects of chemical priming on plant physiology remain to be elucidated. Reactive oxygen, nitrogen and sulfur species (RONSS) are molecules playing a vital role in the stress acclimation of plants. When applied as priming agents, RONSS improve stress tolerance. This review summarizes the recent knowledge on the role of RONSS in cell signalling and gene regulation contributing to abiotic stress tolerance enhancement. Copyright © 2016 Elsevier Ltd. All rights reserved.

The role of char and tar in determining the gas-phase partitioning of nitrogen during biomass gasification

International Nuclear Information System (INIS)

Broer, Karl M.; Brown, Robert C.

2015-01-01

Highlights: • Switchgrass was gasified at an equivalence ratio of zero and 650–850 °C. • Short residence times were employed to minimize secondary reactions. • Char- and tar-bound nitrogen, NH_3, HCN, and N_2 were all significant products. • Increasing temperature leads to increased release of gaseous nitrogen compounds. • Kinetic models of gasification should include nitrogen release from char and tar. - Abstract: Gasification is an attractive option for converting biomass into fuels and chemicals. Most biomass contains significant amounts of fuel-bound nitrogen (FBN), which partially converts into ammonia (NH_3) and hydrogen cyanide (HCN) during gasification. These nitrogen compounds are problematic as they can lead to NO_X emissions or catalyst poisoning in downstream applications of syngas. FBN can convert to other products as well, including diatomic nitrogen (N_2), char-bound nitrogen (char-N), and tar-bound nitrogen (tar-N). Efforts to predict concentrations of NH_3 and HCN have been hindered by a lack of accurate, comprehensive measurements of nitrogen partitioning among gasification products. The present study gasified switchgrass under allothermal, short residence time conditions and measured NH_3, HCN, char-N, and tar-N as a function of temperature in the range of 650–850 °C with diatomic nitrogen determined by difference. It was found that a major portion of FBN was retained in the char and tar products. As temperature was increased, char and tar were consumed, releasing nitrogen as gaseous NH_3 and HCN. This increase in undesirable nitrogen compounds is contrary to the predictions of most gasification models, which overlook the presence of significant nitrogen in char and tar even if they include tar cracking and char gasification reactions. The results of this study demonstrate that gas-phase reactions alone are not sufficient to predict the fate of nitrogen during gasification. In order for modeling efforts to obtain more accurate

Studies of gaseous multiplication coefficient in isobutane using a resistive plate chamber

Energy Technology Data Exchange (ETDEWEB)

Goncalves, Josemary A.C.; Botelho, Suzana; Tobias, Carmen C.B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Pontificia Univ. Catolica de Sao Paulo (PUC/SP), SP (Brazil); Lima, Iara B.; Vivaldini, Tulio C. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Ridenti, Marco A.; Pascholati, Paulo R. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Fisica. Lab. do Acelerador Linear; Fonte, Paulo; Mangiarotti, Alessio [Universidade de Coimbra (Portugal). Dept. de fisica. Lab. de Instrumentacao e Fisica Experimental de Particulas

2009-07-01

Full text: Due to the increasing demands concerning High Energy Physics, Nuclear Medicine and other Nuclear Applications about gaseous detectors operating in high electric fields, many efforts have been done about the choice of filling gases that fulfill these requirements. In this context, the electron transport parameters in gases, as the gaseous multiplication coefficient, play an important role not only for detector design but also for simulation and modeling of discharges, allowing the validation of electron impact cross-sections. In the present work the preliminary measurements of gaseous multiplication coefficient, as function of the reduced electric field (from 36V/cm.Torr until 93V/cm.Torr), for isobutane are presented. Among several filling gases, isobutane is widely used in resistive plate chambers RPCs, and other gaseous detectors, due to its timing properties. Although its characteristics, there is a lack of swarm parameters data in literature for this gas, mainly at high electric fields. The experimental method used is based on the Pulsed Townsend technique, which follows from Townsend equation solution for a uniform electric field. Considering the ratio between the current (I), measured in avalanche mode, and the primary ionization current (I{sub 0}), the effective multiplication coefficient can be determined, since alpha = d{sup -1}ln(I/I{sub 0}), where d is the gap between the electrodes. In our configuration, the experimental setup consists of two parallel plates enclosure in a stainless steel chamber at gas flow regime. The anode, is made of a high resistivity (2.10{sup 12}{omega}.cm) glass (3mm thick and 14mm diameter), while the cathode is of aluminium (40mm diameter). Primary electrons are produced by irradiating the cathode with a nitrogen laser (LTB MNL200-LD) and are accelerated toward the anode by means of a high voltage power supply (Bertan 225-30). In order to validate the technique and to analyze effects of non-uniformity, results for

Thalli Growth, Propagule Survival, and Integrated Physiological Response to Nitrogen Stress of Ramalina calicaris var. japonica in Shennongjia Mountain (China

Directory of Open Access Journals (Sweden)

Chuan-Hua Wang

2018-05-01

Full Text Available In this study, effects of nitrogen (N availability on growth, survival of Ramalina calicaris var. japonica, and whether it respond nitrogen stress in an integrated physiological way was evaluated. Thalli growth and propagule survival, thalli N and phosphorus (P content, and activity of phosphomonoesterase (PME of R. calicaris var. japonica were determined in a field experiment. Its differentiate adsorption in ammonia and nitrate, the activity of glutamine synthetase (GSA and nitrate reductase (NRA also were investigated in a series of indoor experiments. The results showed that N deposition significantly decreased the growth and survival of this lichen, and the N sensitivity threshold was suggested at 6.0 kg N⋅ha-1⋅y-1. When the N deposition increased from 8.59 kg N⋅ha-1⋅y-1 to 14.24, 20.49, 32.99 and 57.99 kg N⋅ha-1⋅y-1, the growth rates of lichen thalli decreased by 26.47, 39.01, 52.18 and 60.3%, respectively; Whereas the survival rate of the lichen propagules decreased from 92.8% of control (0.0 kg N⋅ha-1⋅y-1 to 10.7% of 50.0 kg N⋅ha-1⋅y-1, when they were treated with 0.00, 6.25, 12.5, 25.0, and 50.0 kg N⋅ha-1⋅y-1 deposition. Compared with an adequate adsorption of ammonium N, no nitrate adsorption occurred when thalli was submerged in solution lower than 0.4 mM. Our results also suggested that thalli total nitrogen, N:P ratio increased with N availability, and the activity of PME was significantly correlated with thalli total nitrogen. These all indicated that phosphorus limitation occurred when R. calicaris var. japonica treated with higher nitrogen deposition. Compared with slightly effects of NRA, GSA of R. calicaris var. japonica responded nitrogen availability significantly; In addition, GSA and NRA negatively correlated with thalli growth rate and propagule survival significantly. These results indicated that nitrogen stress do decrease growth and survival of R. calicaris var. japonica, and lichen would be

Testing of a Spray-bar Thermodynamic Vent System in Liquid Nitrogen

Science.gov (United States)

Flachbart, R. H.; Hastings, L. J.; Hedayat, A.; Nelson, S. L.; Tucker, S. P.

2005-01-01

To support development of a microgravity pressure control capability for liquid oxygen, thermodynamic vent system (TVS) testing was conducted at Marshall Space Flight Center (MSFC) using liquid nitrogen (LN2) as a LOX simulant. The spray bar TVS hardware used was originally designed by the Boeing Company for testing in liquid hydrogen (LH2). With this concept, a small portion of the tank fluid is passed through a Joule-Thomson (J-T) device, and then through a longitudinal spray bar mixed-heat exchanger in order to cool the bulk fluid. To accommodate the larger mass flow rates associated with LN2, the TVS hardware was modified by replacing the recirculation pump with an LN2 compatible pump and replacing the J-T valve. The primary advantage of the spray-bar configuration is that tank pressure control can be achieved independent of liquid and vapor location, enhancing the applicability of ground test data to microgravity conditions. Performance testing revealed that the spray-bar TVS was effective in controlling tank pressure within a 6.89 kPa band for fill levels of 90%, 50%, and 25%. Tests were also conducted with gaseous helium (GHe) in the ullage. The TVS operated nominally with GHe in the ullage, with performance similar to the tests with gaseous nitrogen (GN2). Testing demonstrated that the spray-bar TVS design was flexible enough for use in two different propellants with minimal hardware modifications.

Wear characterization of a tool steel surface modified by melting and gaseous alloying

International Nuclear Information System (INIS)

Rizvi, S.A.

1999-01-01

Hot forging dies are subjected to laborious service conditions and so there is a need to explore means of improving die life to increase productivity and quality of forgings. Surface modification in order to produce wear resistant surface is an attractive method as it precludes the need to use expensive and highly alloyed steels. In this study, a novel, inexpensive surface modification technique is used to improve the tri biological properties of an H13 tool steel. Surface melting was achieved using a tungsten heat source and gaseous alloying produced under a shield of argon, carbon dioxide, carbon dioxide-argon mixture and nitrogen gases. The change in wear behaviour was compared through micro-hardness indentation measurements and using a dry sliding pin-on-plate wear testing machine. This study shows superior wear behaviour of the modified surfaces when compared to the untreated surfaces. The increase in wear resistance is attributed to the formation of carbides when surfaces are melted under a carbon dioxide shield. However, in the case of nitrogen and argon gaseous alloying, an increase in wear resistance can be attributed to an increase in surface hardness which in turn effects surface deformation behaviour. (author)

Two new sources of reactive gaseous mercury in the free troposphere

OpenAIRE

H. Timonen; J. L. Ambrose; D. A. Jaffe

2012-01-01

Mercury (Hg) is a neurotoxin that bioaccumulates in the food chain. Mercury is emitted to the atmosphere primarily in its elemental form, which has a long lifetime allowing global transport. It is known that atmospheric oxidation of gaseous elemental mercury (GEM) generates reactive gaseous mercury (RGM) which plays an important role in the atmospheric mercury cycle by enhancing the rate of mercury deposition to ecosystems. However, the primary GEM oxidants, and the sources and chemical ...

Characteristics and applications of small, portable gaseous air pollution monitors.

Science.gov (United States)

McKercher, Grant R; Salmond, Jennifer A; Vanos, Jennifer K

2017-04-01

Traditional approaches for measuring air quality based on fixed measurements are inadequate for personal exposure monitoring. To combat this issue, the use of small, portable gas-sensing air pollution monitoring technologies is increasing, with researchers and individuals employing portable and mobile methods to obtain more spatially and temporally representative air pollution data. However, many commercially available options are built for various applications and based on different technologies, assumptions, and limitations. A review of the monitor characteristics of small, gaseous monitors is missing from current scientific literature. A state-of-the-art review of small, portable monitors that measure ambient gaseous outdoor pollutants was developed to address broad trends during the last 5-10 years, and to help future experimenters interested in studying gaseous air pollutants choose monitors appropriate for their application and sampling needs. Trends in small, portable gaseous air pollution monitor uses and technologies were first identified and discussed in a review of literature. Next, searches of online databases were performed for articles containing specific information related to performance, characteristics, and use of such monitors that measure one or more of three criteria gaseous air pollutants: ozone, nitrogen dioxide, and carbon monoxide. All data were summarized into reference tables for comparison between applications, physical features, sensing capabilities, and costs of the devices. Recent portable monitoring trends are strongly related to associated applications and audiences. Fundamental research requires monitors with the best individual performance, and thus the highest cost technology. Monitor networking favors real-time capabilities and moderate cost for greater reproduction. Citizen science and crowdsourcing applications allow for lower-cost components; however important strengths and limitations for each application must be addressed

Differential growth responses of Brachypodium distachyon genotypes to inoculation with plant growth promoting rhizobacteria.

Science.gov (United States)

do Amaral, Fernanda P; Pankievicz, Vânia C S; Arisi, Ana Carolina M; de Souza, Emanuel M; Pedrosa, Fabio; Stacey, Gary

2016-04-01

Plant growth promoting rhizobacteria (PGPR) can associate and enhance the growth of important crop grasses. However, in most cases, the molecular mechanisms responsible for growth promotion are not known. Such research could benefit by the adoption of a grass model species that showed a positive response to bacterial inoculation and was amenable to genetic and molecular research methods. In this work we inoculated different genotypes of the model grass Brachypodium distachyon with two, well-characterized PGPR bacteria, Azospirillum brasilense and Herbaspirillum seropedicae, and evaluated the growth response. Plants were grown in soil under no nitrogen or with low nitrogen (i.e., 0.5 mM KNO3). A variety of growth parameters (e.g., shoot height, root length, number of lateral roots, fresh and dry weight) were measured 35 days after inoculation. The data indicate that plant genotype plays a very important role in determining the plant response to PGPR inoculation. A positive growth response was observed with only four genotypes grown under no nitrogen and three genotypes tested under low nitrogen. However, in contrast, relatively good root colonization was seen with most genotypes, as measured by drop plate counting and direct, microscopic examination of roots. In particular, the endophytic bacteria H. seropedicae showed strong epiphytic and endophytic colonization of roots.

Effects of application of inhibitors and biochar to fertilizer on gaseous nitrogen emissions from an intensively managed wheat field.

Science.gov (United States)

He, Tiehu; Liu, Deyan; Yuan, Junji; Luo, Jiafa; Lindsey, Stuart; Bolan, Nanthi; Ding, Weixin

2018-07-01

The effects of biochar combined with the urease inhibitor, hydroquinone, and nitrification inhibitor, dicyandiamide, on gaseous nitrogen (N 2 O, NO and NH 3 ) emissions and wheat yield were examined in a wheat crop cultivated in a rice-wheat rotation system in the Taihu Lake region of China. Eight treatments comprised N fertilizer at a conventional application rate of 150kgNha -1 (CN); N fertilizer at an optimal application rate of 125kgNha -1 (ON); ON+wheat-derived biochar at rates of 7.5 (ONB1) and 15tha -1 (ONB2); ON+nitrification and urease inhibitors (ONI); ONI+wheat-derived biochar at rates of 7.5 (ONIB1) and 15tha -1 (ONIB2); and, a control. The reduced N fertilizer application rate in the ON treatment decreased N 2 O, NO, and NH 3 emissions by 45.7%, 17.1%, and 12.3%, respectively, compared with the CN treatment. Biochar application increased soil organic carbon, total N, and pH, and also increased NH 3 and N 2 O emissions by 32.4-68.2% and 9.4-35.2%, respectively, compared with the ON treatment. In contrast, addition of urease and nitrification inhibitors decreased N 2 O, NO, and NH 3 emissions by 11.3%, 37.9%, and 38.5%, respectively. The combined application of biochar and inhibitors more effectively reduced N 2 O and NO emissions by 49.1-49.7% and 51.7-55.2%, respectively, compared with ON and decreased NH 3 emission by 33.4-35.2% compared with the ONB1 and ONB2 treatments. Compared with the ON treatment, biochar amendment, either alone or in combination with inhibitors, increased wheat yield and N use efficiency (NUE), while addition of inhibitors alone increased NUE but not wheat yield. We suggest that an optimal N fertilizer rate and combined application of inhibitors+biochar at a low application rate, instead of biochar application alone, could increase soil fertility and wheat yields, and mitigate gaseous N emissions. Copyright © 2018 Elsevier B.V. All rights reserved.

Enzyme Production and Nitrogen Fixation by Free, Immobilized and Coimmobilized Inoculants of Trichoderma harzianum and Azospirillum brasilense and Their Possible Role in Growth Promotion of Tomato

Directory of Open Access Journals (Sweden)

Momein H. El-Katatny

2010-01-01

Full Text Available A plant growth-promoting rhizobacterium (Azospirillum brasilense strain Az and a biocontrol fungus (Trichoderma harzianum strain T24 have been evaluated for their individual and combined production of hydrolytic enzymes, nitrogen fixation and their possible role in growth promotion of tomato seedlings. The studied organisms were inoculated as free or calcium alginate-encapsulated cells. All freshly prepared macrobeads showed high encapsulation capacity (EC/% of inocula compared with dry macrobeads. Results of enzyme production did not exhibit consistent pattern of the effect of encapsulation process on enzyme production. Beads entrapping bacterial and/or fungal cells were used successfully in 3 repeated cycles in the presence of fresh sterile culture medium in each growth cycle. Enzyme production by immobilized bacterial and/or fungal cells increased as the growth cycles were repeated. Co-culturing of A. brasilense with T. harzianum (free or immobilized in semisolid nitrogen deficient medium (N-free medium enabled A. brasilense to fix nitrogen on pectin, chitin and carboxymethyl cellulose. The activity of nitrogen fixation by A. brasilense in the case of single and combined cultures with Trichoderma (using dry encapsulated beads into the sterile soil increased with the addition of carbon source. Most of inoculations with free or alginate macrobead formulations of T. harzianum and/or A. brasilense showed significant increase in the growth parameters of tomato seedlings. The root system grew more profusely in the case of all seeds treated with A. brasilense. The growth parameters of Az/T24-treated seeds using dry coimmobilized macrobeads were higher than those of the untreated control. Moreover, the effect was improved significantly in soil enriched with different C sources. Enhanced tomato seedling growth after the co-inoculation could be due to the synergistic effect of both Trichoderma and Azospirillum. Finally, co-inoculation with Azospirillum

Optimation of Nitrogen and Phosphorus in Azolla Growth as Biofertilizer

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Hany Handajani

2013-03-01

Full Text Available Nitrogen is one of the most important minerals for living organisms. Azolla is known as a small water fern which can fix nitrogen through the symbiotic association with the blue green algae Anabaena. Experimental studies were carried out in the glass house, investigating the growth of Azolla using different levels of nitrogen and phosphorus in the media. The experiment used 12 treatments with 3 levels of nitrogen (0, 5, and 10 mg atom/L and 4 levels of phosphorus (0, 10, 20, and 30 mg atom/l in a factorial design with 3 replicates. The results show that the highest biomass for fresh weight (13.28 g, dry weight (1,126 g, and the fastest doubling time (7.71 days were found in combination of 10 mg atom/L N and 30 mg atom/L P. Meanwhile, the highest protein content was found in combination of 5 mg atom/L N and 20 mg atom/L P. After the third day heterocyst cells in Anabaena could only be found in those two combinations, but the highest heterocyst cells was found in the lower N and P combination similar to the highest protein content. Further experiment is suggested to introduce Azolla as bio-fertilizer for acid water system, such as peat land water.

Development of gaseous photomultiplier

International Nuclear Information System (INIS)

Tokanai, F.; Sumiyoshi, T.; Sugiyama, H.; Okada, T.

2014-01-01

We have been developing gaseous photomultiplier tubes (PMTs) with alkali photocathode combined with micropattern gas detectors (MPGDs). The potential advantage of the gaseous PMT is that it can achieve a very large effective area with adequate position and timing resolutions. In addition, it will be easily operated under a very high magnetic field, compared with the conventional vacuum-based PMT. To evaluate the gaseous PMTs filled with Ne and Ar based gas mixture, we have developed gaseous PMTs with an alkali photocathode combined with MPGDs such as a glass capillary plate, GEM, and Micromegas detector. We describe the recent development of the gaseous PMTs, particularly the production of the photocathode, gas gain, ion and photon feedbacks, quantum efficiency, and the characteristics in the magnetic field environment. (author)

Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy

Science.gov (United States)

Gunning, Brendan P.; Clinton, Evan A.; Merola, Joseph J.; Doolittle, W. Alan; Bresnahan, Rich C.

2015-10-01

Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N2 while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N2 and 7.7 sccm Ar flows at 600 W radio frequency power, for which the standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 1016 to 3.8 × 1019 cm-3 were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1-2 × 1015 cm-3. The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be addressed. Nonetheless, the dramatically enhanced growth rates demonstrate

Quantification of growth, yield and radiation use efficiency of promising cotton cultivars at varying nitrogen levels

International Nuclear Information System (INIS)

Wajid, A.; Ahmad, A.; Khaliq, T.; Alam, S.; Hussaun, A.; Hussain, K.; Naseem, W.; Usman, M.; Ahmad, S.

2010-01-01

Cotton cultivars response to different doses of nitrogen for radiation interception, canopy development, growth and seed yield were studied in 2006. The experiment was laid out in randomized complete block design with split arrangement under the climatic conditions of Bahawalpur. Data on seed yield, total dry matter (TDM), leaf area index (LAI), fraction of intercepted radiation (Fi), accumulated radiation interception during the growth season (Sa) and radiation use efficiency (RUE) were taken into account. TDM pattern showed sigmoid growth curve for both cultivars and nitrogen levels and showed strong relationship (R2 = 0.98) with the accumulated intercepted radiation (Sa) for the season. Mean maximum value of fraction of incident PAR (Fi) remained 90% at 120 days after sowing (DAS) harvest due to maximum crop canopy development. Cultivar NIAB-111 produced 0.81 g m/sup -2/ of TDM for each MJ of accumulated PAR and nitrogen at the rate of 185 kg ha/sup -1/ statistically proved to be better in converting radiation into dry matter production. (author)

Development of benzene, toluene, ethylbenzene and xylenes certified gaseous reference materials

Science.gov (United States)

Brum, M. C.; Sobrinho, D. C. G.; Fagundes, F. A.; Oudwater, R. J.; Augusto, C. R.

2016-07-01

The work describes the production of certified gaseous reference materials of benzene, toluene, ethylbenzene and xylenes (BTEX) in nitrogen from the gravimetric production up to the long term stability tests followed by the certifying step. The uncertainty in the amount fractions of the compounds in these mixtures was approximately 4% (relative) for the range studied from 2 to 16 µmol/mol. Also the adsorption of the BTEX on the cylinder surface and the tubing were investigated as potential uncertainty source.

Enhanced nitrogen removal from piggery wastewater with high NH4+ and low COD/TN ratio in a novel upflow microaerobic biofilm reactor.

Science.gov (United States)

Meng, Jia; Li, Jiuling; Li, Jianzheng; Antwi, Philip; Deng, Kaiwen; Nan, Jun; Xu, Pianpian

2018-02-01

To enhance nutrient removal more cost-efficiently in microaerobic process treating piggery wastewater characterized by high ammonium (NH 4 + -N) and low chemical oxygen demand (COD) to total nitrogen (TN) ratio, a novel upflow microaerobic biofilm reactor (UMBR) was constructed and the efficiency in nutrient removal was evaluated with various influent COD/TN ratios and reflux ratios. The results showed that the biofilm on the carriers had increased the biomass in the UMBR and enhanced the enrichment of slow-growth-rate bacteria such as nitrifiers, denitrifiers and anammox bacteria. The packed bed allowed the microaerobic biofilm process perform well at a low reflux ratio of 35 with a NH 4 + -N and TN removal as high as 93.1% and 89.9%, respectively. Compared with the previously developed upflow microaerobic sludge reactor, the UMBR had not changed the dominant anammox approach to nitrogen removal, but was more cost-efficiently in treating organic wastewater with high NH 4 + -N and low COD/TN ratio. Copyright © 2017 Elsevier Ltd. All rights reserved.

Growth Analysis of Fenugreek (Trigonella foenum- graecum L. under Various Levels of Nitrogen and Plant Density

Directory of Open Access Journals (Sweden)

L Bazrkar-Khatibani

2018-02-01

Full Text Available Introduction Fenugreek (Trigonella foenum-graecum L. is a specific condiment crop mostly grown for its edible parts, and is used as a green fodder and fresh vegetable. The seeds have medicinal value solely against digestive disorders, whereas its leaves are rich source of minerals and nutrients. The growth and yield of fenugreek is particularly affected by the application of nitrogen fertilizer and planting arrangement. Plant growth is a process of biomass accumulation which in turn is derived out of the interaction of the respiration, photosynthesis, water relations, long-distance transport, and mineral nutrition processes. Growth is the most important process in predicting plant reactions to environment. Irradiance, temperature, soil-water potential, nutrient supply and enhanced concentrations of atmospheric carbon dioxide are among some external components influencing crop growth and development. Growth analysis is a useful tool in studying the complex interactions between plant growth and the environment, clarifying and interpreting physiological responses. Plants total dry matter (TDM production and accumulation can be appraised via relative growth rate (RGR and crop growth rate (CGR which are the most important growth indices. Leaf area index (LAI is a factor of crop growth analysis that accounts for the potential of the crop to assimilate light energy and is a determinant component in understanding the function of many crop management practices. Materials and Methods A field investigation was conducted in a paddy field at Shaft County (Guilan Province for eight consecutive months (from November 2009 to June 2010, to study the effect of four levels of nitrogen fertilizer (0, 25, 50 and 75 Kg N ha-1 and four levels of planting density (60, 80,100, and 120 plants m-2 on the growth indices of fenugreek (Trigonella foenum graecum L. crop. The soil for the experiment was loam in texture and strongly acidic in reaction (pH 4.5. Sixteen treatment

Mevva ion source operated in purely gaseous mode

International Nuclear Information System (INIS)

Yushkov, G.Y.; MacGill, R.A.; Brown, I. G.

2003-01-01

We have operated a vacuum arc ion source in such a way as to form beams of purely gaseous ions. The vacuum arc configuration that is conventionally used to produce intense beams of metal ions was altered so as to form gaseous ion beams, with only minimal changes to the external circuitry and no changes at all internally to the ion source. In our experiments we formed beams from oxygen (O + and O 2 + ), nitrogen (N + and N 2 + ), argon (Ar + ) and carbon dioxide (C + , CO 2 + , O + and O 2 + ) at extraction voltage of 2 to 50 kV. We used a pulsed mode of operation, with beam pulses approximately 50 milliseconds long and repetition rate 10 pulses per second, for a duty cycle of about 50%. Downstream ion beam current as measured by a 5 cm diameter Faraday cup was typically 0.5 mA pulse or about 250 (micro)A time averaged. This time averaged beam current is very similar to that obtained for metal ions when the source is operated in the usual vacuum arc mode. Here we describe the modifications made to the source and the results of our investigations

Cyanobacteria in CELSS: Growth strategies for nutritional variation and nitrogen cycling

Science.gov (United States)

Fry, I. V.; Packer, L.

1990-01-01

Cyanobacteria (blue-green algae) are versatile organisms which are capable of adjusting their cellular levels of carbohydrate, protein, and lipid in response to changes in the environment. Under stress conditions there is an imbalance between nitrogen metabolism and carbohydrate/lipid synthesis. The lesion in nitrogen assimilation is at the level of transport: the stress condition diverts energy from the active accumulation of nitrate to the extrusion of salt, and probably inhibits a cold-labile ATP'ace in the case of cold shock. Both situations affect the bioenergetic status of the cell such that the nitrogenous precursors for protein synthesis are depleted. Dispite the inhibition of protein synthesis and growth, photosynthetic reductant generation is relatively unaffected. The high O2 reductant would normally lead to photo-oxidative damage of cellular components; however, the organism copes by channeling the 'excess' reductant into carbon storage products. The increase in glycogen (28 to 35 percent dry weight increase) and the elongation of lipid fatty acid side chains (2 to 5 percent dry weight increase) at the expense of protein synthesis (25 to 34 percent dry weight decrease) results in carbohydrate, lipid and protein ratios that are closer to those required in the human diet. In addition, the selection of nitrogen fixing mutants which excrete ammonium ions present an opportunity to tailor these micro-organisms to meet the specific need for a sub-system to reverse potential loss of fixed nitrogen material.

Cryogenically enhanced magneto-Archimedes levitation

Energy Technology Data Exchange (ETDEWEB)

Catherall, A T; Lopez-Alcaraz, P; Benedict, K A; King, P J; Eaves, L [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

2005-05-01

The application of both a strong magnetic field and magnetic field gradient to a diamagnetic body can produce a vertical force which is sufficient to counteract its weight due to gravity. By immersing the body in a paramagnetic fluid, an additional adjustable magneto-buoyancy force is generated which enhances the levitation effect. Here we show that cryogenic oxygen and oxygen-nitrogen mixtures in both gaseous and liquid form provide sufficient buoyancy to permit the levitation and flotation of a wide range of materials. These fluids may provide an alternative to synthetic ferrofluids for the separation of minerals. We also report the dynamics of corrugation instabilities on the surface of magnetized liquid oxygen.

Cryogenically enhanced magneto-Archimedes levitation

International Nuclear Information System (INIS)

Catherall, A T; Lopez-Alcaraz, P; Benedict, K A; King, P J; Eaves, L

2005-01-01

The application of both a strong magnetic field and magnetic field gradient to a diamagnetic body can produce a vertical force which is sufficient to counteract its weight due to gravity. By immersing the body in a paramagnetic fluid, an additional adjustable magneto-buoyancy force is generated which enhances the levitation effect. Here we show that cryogenic oxygen and oxygen-nitrogen mixtures in both gaseous and liquid form provide sufficient buoyancy to permit the levitation and flotation of a wide range of materials. These fluids may provide an alternative to synthetic ferrofluids for the separation of minerals. We also report the dynamics of corrugation instabilities on the surface of magnetized liquid oxygen

Gaseous poison injection device

International Nuclear Information System (INIS)

Kubota, Ryuji; Sugisaki, Toshihiko; Inada, Ikuo.

1983-01-01

Purpose: To rapidly control the chain reaction due to thermal neutrons in a reactor core by using gaseous poisons as back-up means for control rod drives. Constitution: Gaseous poisons having a large neutron absorption cross section are used as back-up means for control rod drives. Upon failure of control rod insertion, the gaseous poisons are injected into the lower portion of the reactor core to control the reactor power. As the gaseous poisons, vapors at a high temperature and a higher pressure than that of the coolants in the reactor core are injected to control the reactor power due to the void effects. Since the gaseous poisons thus employed rapidly reach the reactor core and form gas bubbles therein, the deccelerating effect of the thermal neutrons is decreased to reduce the chain reaction. (Moriyama, K.)

Intrinsic fatigue crack propagation in aluminum-lithium alloys - The effect of gaseous environments

Science.gov (United States)

Piascik, Robert S.; Gangloff, Richard P.

1989-01-01

Gaseous environmental effects on intrinsic fatigue crack growth are significant for the Al-Li-Cu alloy 2090, peak aged. For both moderate Delta K-low R and low Delta K-high R regimes, crack growth rates decrease according to the environment order: purified water vapor, moist air, helium and oxygen. Gaseous environmental effects are pronounced near threshold and are not closure dominated. Here, embrittlement by low levels of H2O (ppm) supports hydrogen embrittlement and suggests that molecular transport controlled cracking, established for high Delta K-low R, is modified near threshold. Localized crack tip reaction sites or high R crack opening shape may enable the strong, environmental effect at low levels of Delta K. Similar crack growth in He and O2 eliminates the contribution of surface films to fatigue damage in alloy 2090. While 2090 and 7075 exhibit similar environmental trends, the Al-Li-Cu alloy is more resistant to intrinsic corrosion fatigue crack growth.

Effects of Different Amounts of Nitrogen and Azotobarvar on Growth Characteristics and Yield of Chickpea (Cicer arietinum L.

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ghobad mohammadpoor

2017-09-01

Full Text Available Introduction One of the most important agricultural efforts is to minimize the use of chemicals nitrogen fertilizers and to replace it with biological nitrogen fertilizers to produce healthy productions. In dry conditions the use of industrial nitrogen fertilizers depends on the amount of rainfall and consumed cautiously. Low consumption of nitrogen sources reduce crop growth and yield and higher than optimum applications of chemical Nitrogen sources can cause many environmental disorders. This is while Azotobacter as a soil bacteria also fixes nitrogen, produce vitamins, growth hormones and antibiotics and also increases the photosynthesis, plant growth and grain yield and reduces the need to application of chemical Nitrogen. Materials and Methods In order to study the effect of biological and industrial nitrogen fertilizers on growth, yield and yield components of chickpea (Bivanij variety, an experiment was conducted with split plot arrangement based on randomized complete block design (RCBD with four replications under rainfed conditions in the Telesm village, Dalahoo, Kermanshah, during 2013 agricultural season. Climate of the region is temperate and semi-arid with 535.6 mm of rainfall. Soil texture is clay - loam with 0.02 percent of nitrogen. Basic amount of Nitrogen fertilizer was considered 30 Kg.ha-1 Urea and four levels of chemical nitrogen fertilizers including: %50 of base fertilizer, %100 of base fertilizer, %150 of base fertilizer and no fertilizer (control were assumed as main plot factors. Similarly, the basic amount of Azotobarvar bio-fertilizer was considered as 100 g.ha-1 and four levels of it including %50 of base fertilizer, %100 of base fertilizer, %150 of base fertilizer and no bio-fertilizer (control were assumed as sub plot factors. Bio-fertilizers are inoculated to seeds and planting was done manually on 19 March 2013. Density was considered 40 plants per square meter with 25 cm intervals between rows and 10 cm on the

Nucleation and Growth of GaN on GaAs (001) Substrates

International Nuclear Information System (INIS)

Drummond, Timothy J.; Hafich, Michael J.; Heller, Edwin J.; Lee, Stephen R.; Liliental-Weber, Zuzanna; Ruvimov, Sergei; Sullivan, John P.

1999-01-01

The nucleation of GaN thin films on GaAs is investigated for growth at 620 ''C. An rf plasma cell is used to generate chemically active nitrogen from N 2 . An arsenic flux is used in the first eight monolayer of nitride growth to enhance nucleation of the cubic phase. Subsequent growth does not require an As flux to preserve the cubic phase. The nucleation of smooth interfaces and GaN films with low stacking fault densities is dependent upon relative concentrations of active nitrogen species in the plasma and on the nitrogen to gallium flux ratio

Emissions of gaseous nitrogen species from manure management: A new approach

International Nuclear Information System (INIS)

Daemmgen, Ulrich; Hutchings, Nicholas J.

2008-01-01

A procedure for the assessment of emissions of nitrogen (N) species (ammonia, nitrous oxide, nitric oxide, di-nitrogen) from the manure management system is developed, which treats N pools and flows including emissions strictly according to conservation of mass criteria. As all relevant flows in the husbandry of mammals are depicted, the methodology is considered a Tier 3 approach in IPCC terminology or a detailed methodology in UN ECE terminology. The importance of accounting for all N species is illustrated by comparing emission estimates obtained using this approach with those obtained from the application the present detailed/Tier 2 methodology. - A cow is a cow. There is no distinction between an IPCC and a UN ECE cow!

Emissions of gaseous nitrogen species from manure management: A new approach

Energy Technology Data Exchange (ETDEWEB)

Daemmgen, Ulrich [Federal Agricultural Research Centre, Institute of Agroecology, Bundesallee 50, 38116 Braunschweig (Germany)], E-mail: ulrich.daemmgen@fal.de; Hutchings, Nicholas J. [Danish Institute of Agricultural Sciences, Department of Agroecology, Tjele (Denmark)], E-mail: nick.hutchings@agrsci.dk

2008-08-15

A procedure for the assessment of emissions of nitrogen (N) species (ammonia, nitrous oxide, nitric oxide, di-nitrogen) from the manure management system is developed, which treats N pools and flows including emissions strictly according to conservation of mass criteria. As all relevant flows in the husbandry of mammals are depicted, the methodology is considered a Tier 3 approach in IPCC terminology or a detailed methodology in UN ECE terminology. The importance of accounting for all N species is illustrated by comparing emission estimates obtained using this approach with those obtained from the application the present detailed/Tier 2 methodology. - A cow is a cow. There is no distinction between an IPCC and a UN ECE cow{exclamation_point}.

Growth and yield of cucumber as influenced by compost and nitrogen fertilizer in sandy soils using the nuclear technique for determination of nitrogen

International Nuclear Information System (INIS)

El-Sherif, M.F.A.

2005-01-01

this study was carried out during the period from 2002 to 2003 seasons, at the department of plant research, Nuclear Research Center (NRC,) Atomic Energy Authority (AEA), Egypt, on cucumber plants c.v. dp007 F1 (wafer). the main objective of this work was to study the effect of compost type, application level and nitrogen rate on vegetative growth, chemical composition, early and total yield and to determine the fertilizer nitrogen uptake and utilization by the cucumber plant and its parts, i.e., shoots and fruits . results revealed that the sugar cane bagasse compost (SC) gave a significantly higher response with most vegetative growth expressed as plant length, leaf number and dry weight of cucumber plant, compared with beet compost (BC). the application of compost from 2 up to 6 ton/fed

Effect of Growth Temperature on Bamboo-shaped Carbon–Nitrogen (C–N Nanotubes Synthesized Using Ferrocene Acetonitrile Precursor

Directory of Open Access Journals (Sweden)

Dobal PramodSingh

2008-01-01

Full Text Available Abstract This investigation deals with the effect of growth temperature on the microstructure, nitrogen content, and crystallinity of C–N nanotubes. The X-ray photoelectron spectroscopic (XPS study reveals that the atomic percentage of nitrogen content in nanotubes decreases with an increase in growth temperature. Transmission electron microscopic investigations indicate that the bamboo compartment distance increases with an increase in growth temperature. The diameter of the nanotubes also increases with increasing growth temperature. Raman modes sharpen while the normalized intensity of the defect mode decreases almost linearly with increasing growth temperature. These changes are attributed to the reduction of defect concentration due to an increase in crystal planar domain sizes in graphite sheets with increasing temperature. Both XPS and Raman spectral observations indicate that the C–N nanotubes grown at lower temperatures possess higher degree of disorder and higher N incorporation.

Safety in handling helium and nitrogen

International Nuclear Information System (INIS)

Schmauch, G.; Lansing, L.; Santay, T.; Nahmias, D.

1991-01-01

Based upon the authors' industrial experience and practices, they have provided an overview of safety in storage, handling, and transfer of both laboratory and bulk quantities of gaseous and liquid forms of nitrogen and helium. They have addressed the properties and characteristics of both the gaseous and liquid fluids, typical storage and transport containers, transfer techniques, and the associated hazards which include low temperatures, high pressures, and asphyxiation. Methods and procedures to control and eliminate these hazards are described, as well as risk remediation through safety awareness training, personal protective equipment, area ventilation, and atmosphere monitoring. They have included as an example a recent process hazards analysis performed by Air Products on the asphyxiation hazard associated with the use of liquid helium in MRI magnet systems

Influences of Air, Oxygen, Nitrogen, and Carbon Dioxide Nanobubbles on Seed Germination and Plant Growth.

Science.gov (United States)

Ahmed, Ahmed Khaled Abdella; Shi, Xiaonan; Hua, Likun; Manzueta, Leidy; Qing, Weihua; Marhaba, Taha; Zhang, Wen

2018-05-23

Nanobubbles (NBs) hold promise in green and sustainable engineering applications in diverse fields (e.g., water/wastewater treatment, food processing, medical applications, and agriculture). This study investigated the effects of four types of NBs on seed germination and plant growth. Air, oxygen, nitrogen, and carbon dioxide NBs were generated and dispersed in tap water. Different plants, including lettuce, carrot, fava bean, and tomato, were used in germination and growth tests. The seeds in water-containing NBs exhibited 6-25% higher germination rates. Especially, nitrogen NBs exhibited considerable effects in the seed germination, whereas air and carbon dioxide NBs did not significantly promote germination. The growth of stem length and diameter, leave number, and leave width were promoted by NBs (except air). Furthermore, the promotion effect was primarily ascribed to the generation of exogenous reactive oxygen species by NBs and higher efficiency of nutrient fixation or utilization.

Effects of UV-B radiation on growth, photosynthesis, UV-B-absorbing compounds and NADP-malic enzyme in bean (Phaseolus vulgaris L.) grown under different nitrogen conditions.

Science.gov (United States)

Pinto, M E; Casati, P; Hsu, T P; Ku, M S; Edwards, G E

1999-02-01

The effects of UV-B radiation on growth, photosynthesis, UV-B-absorbing compounds and NADP-malic enzyme have been examined in different cultivars of Phaseolous vulgaris L. grown under 1 and 12 mM nitrogen. Low nitrogen nutrition reduces chlorophyll and soluble protein contents in the leaves and thus the photosynthesis rate and dry-matter accumulation. Chlorophyll, soluble protein and Rubisco contents and photosynthesis rate are not significantly altered by ambient levels of UV-B radiation (17 microW m-2, 290-320 nm, 4 h/day for one week). Comparative studies show that under high nitrogen, UV-B radiation slightly enhances leaf expansion and dry-matter accumulation in cultivar Pinto, but inhibits these parameters in Vilmorin. These results suggest that the UV-B effect on growth is mediated through leaf expansion, which is particularly sensitive to UV-B, and that Pinto is more tolerant than Vilmorin. The effect of UV-B radiation on UV-B-absorbing compounds and on NADP-malic enzyme (NADP-ME) activity is also examined. Both UV-B radiation and low-nitrogen nutrition enhance the content of UV-B-absorbing compounds, and among the three cultivars used, Pinto exhibits the highest increases and Arroz the lowest. The same trend is observed for the specific activity and content of NADP-ME. On a leaf-area basis, the amount of UV-B-absorbing compounds is highly correlated with the enzyme activity (r2 = 0.83), suggesting that NADP-ME plays a key role in biosynthesis of these compounds. Furthermore, the higher sensitivity of Vilmorin than Pinto to UV-B radiation appears to be related to the activity of NADP-ME and the capacity of the plants to accumulate UV-B-absorbing compounds.

Nitrogen dioxide exposures inside ice skating rinks.

Science.gov (United States)

Brauer, M; Spengler, J D

1994-01-01

OBJECTIVES. The common operation of fuel-powered resurfacing equipment in enclosed ice skating rinks has the potential for producing high concentrations of carbon monoxide and nitrogen dioxide. Exposures to these gaseous combustion products may adversely affect the health of those inside the rink. Little information is available on pollutant concentrations under normal operating conditions. METHODS. One-week average nitrogen dioxide concentrations in 70 northeastern US rinks were measured with passive samplers during normal winter season conditions. RESULTS. The median nitrogen dioxide level inside rinks was 180 ppb, more than 10 times higher than the median outdoor concentration. One-week average nitrogen dioxide concentrations above 1000 ppb were measured in 10% of the rinks. CONCLUSIONS. Considering that short-term peak concentrations were likely to have reached two to five times the measured 1-week averages, our results suggest that nitrogen dioxide levels were well above short-term air quality guidelines and constitute a public health concern of considerable magnitude. PMID:8129060

A new mathematical model for nitrogen gas production with special emphasis on the role of attached growth media in anammox hybrid reactor.

Science.gov (United States)

Tomar, Swati; Gupta, Sunil Kumar

2015-11-01

The present study emphasised on the development of new mathematical models based on mass balance and stoichiometry of nitrogen removal in anammox hybrid reactor (AHR). The performance of AHR at varying hydraulic retention times (HRTs) and nitrogen loading rates (NLRs) revealed that nitrogen removal efficiency (NRE) increases with increase in HRT and was found optimal (89 %) at HRT of 2 days. Mass balance of nitrogen revealed that major fraction (74.1 %) of input nitrogen is converted into N2 gas followed by 11.2 % utilised in biomass synthesis. Attached growth media (AGM) in AHR contributed to an additional 15.4 % ammonium removal and reduced the sludge washout rate by 29 %. This also enhanced the sludge retention capacity of AHR and thus minimised the formation of nitrate in the treated effluent, which is one of the bottlenecks of anammox process. Process kinetics was also studied using various mathematical models. The mass balance model derived from total nitrogen was found most precise and predicted N2 gas with least error (1.68 ± 4.44 %). Model validation for substrate removal kinetics dictated comparatively higher correlation for Grau second-order model (0.952) than modified Stover-Kincannon model (0.920). The study concluded that owing to features of high biomass retention, less nitrate formation and consistently higher nitrogen removal efficiency, this reactor configuration is techno-economically most efficient and viable. The study opens the door for researchers and scientists for pilot-scale testing of AHR leading to its wide industrial application.

Method for combined removal of mercury and nitrogen oxides from off-gas streams

Science.gov (United States)

Mendelsohn, Marshall H [Downers Grove, IL; Livengood, C David [Lockport, IL

2006-10-10

A method for removing elemental Hg and nitric oxide simultaneously from a gas stream is provided whereby the gas stream is reacted with gaseous chlorinated compound to convert the elemental mercury to soluble mercury compounds and the nitric oxide to nitrogen dioxide. The method works to remove either mercury or nitrogen oxide in the absence or presence of each other.

Fate of nitrogenous fertilizers in forest soil

International Nuclear Information System (INIS)

Pang, P.C.K.

1984-01-01

The fate of the nitrogenous fertilizers through the processes of denitrification, ammonia volatilization, immobilization and uptake by a conifer is determined, with the aid of 15 N-labelled fertizers. The foliage of Douglas-fir was able to absorb gaseous ammonia under optimal conditions. Denitrification and immobilization of fertilizer-N by forest soil were highest with forest floor samples and decreased with depth. Laboratory studies with four-year-old Douglas-fir demostrated that a higher quantity of fertilizer-N was utilized by trees when the nitrogen was supplied as NO 3 - rather than NH 4 + . (M.A.C.) [pt

[Rice endogenous nitrogen fixing and growth promoting bacterium Herbaspirillum seropedicae DX35].

Science.gov (United States)

Wang, Xiucheng; Cao, Yanhua; Tang, Xue; Ma, Xiaotong; Gao, Jusheng; Zhang, Xiaoxia

2014-03-04

To screen efficient nitrogen fixation endophytes from rice and to analyze their growth-promoting properties. We isolated strains from the roots of rice in the field where it has a rice-rice-green manure rotation system for 30 years. Efficient strains were screened by acetylene reduction assay. Phylogenetic analysis is based on 16S rRNA gene, nifH gene and the composition of fatty acid. In addition, we also detected the ability of indole acetic acid secretion through the Salkowski colorimetric method, measured the production of siderophore through the blue plate assay and detected phosphate solubilization, to analyze the growth-promoting properties. A total of 48 strains were isolated, in which DX35 has the highest nitrogenase activity. It belongs to Herbaspirillum seropedicae after identification. Its nitrogenase activity (181.21 nmol C2H4/(mg protein x h)) was 10 times as much as the reference strain Azotobacter chroococcum ACCC10006. In addition, it also can secrete siderophore and solubilize phosphorus. Strain DX35, belonging to Herbaspirillum seropedicae, is an efficient nitrogen fixation endophytes.

Infuences of Rice Husk Biochar (RHB on Rice Growth Performance and Fertilizer Nitrogen Recovery up to Maximum Tillering Stage

Directory of Open Access Journals (Sweden)

Deniel Anak Sang

2018-03-01

Full Text Available A pot study was carried out to investigate the effects of rice husk biochar addition on rice growth performance and fertilizer nitrogen recovery. The biochar effect was studied by using 15N labelled fertilizer urea (10 atom% 15N, as isotopic tracer, until maximum tillering stage (75 days after sowing. Rice husk biochar (RHB was applied at rates of 0, 5, 10 and 20 Mg ha-1 and laid in randomized complete block design with four replications. The result showed that biochar application significantly improved soil chemical properties (pH, total C, total N, and available P compared to control treatment. Biochar addition increased number of tiller and root dry matter weight up to 4% and 35%, respectively, compared to un-amended pot. Likewise, application of biochar significantly increased N, P and K uptake by 3%, 19% and 33%, respectively, as compared to the nutrient uptake from the control treatment. Biochar treatment had no significant impact on fertilizer nitrogen recovery in aboveground biomass, in the range of 41% and 42%, in comparison to the control. However, nitrogen fertilizer recovery in soil significantly increased by 47% over the control at application rate of 20 Mg ha-1 RHB.  Increased fertilizer N recovery in soil possibly reduced N losses to the environment from volatilization and denitrification processes. Total 15N fertilizer recovery also found increase at highest application of RHB biochar with an increment of 16%. In general, addition of biochar appeared to enhance crop growth performance but its effect on fertilizer N recovery in plant requires further study up to maturity of rice plant.

Preparation of ZnS@In2S3 Core@shell Composite for Enhanced Photocatalytic Degradation of Gaseous o-Dichlorobenzene under Visible Light.

Science.gov (United States)

Liu, Baojun; Hu, Xia; Li, Xinyong; Li, Ying; Chen, Chang; Lam, Kwok-Ho

2017-11-27

In this study, novel ZnS@In 2 S 3 core@shell hollow nanospheres were fabricated by a facile refluxing method for the first time, and the formation mechanism of hollow structure with interior architecture was discussed based on ion-exchange Ostwald ripening. As the photocatalytic material for degradation of gaseous o-Dichlorobenzene (o-DCB), the as-synthesized core@shell hollow nanospheres were found to show significantly enhanced catalytic performance for effective separation of photo-generated charges. Moreover, the mechanisms of enhanced activity were elucidated by band alignment and unique configuration. Such photocatalyst would meet the demands for the control of persistent organic pollutant (POPs) in the atmospheric environment.

Influence of nitrogen on the growth and the properties of InAs quantum dots

International Nuclear Information System (INIS)

Schumann, O.

2004-01-01

This work investigates the influence of nitrogen incorporation on the growth and the optical properties of InAs quantum dots on GaAs(001) substrates. On the basis of systematic growth interruptions it was shown that the large quantum dots nucleate at dislocations, which are already formed during the growth of the wetting layer. After solving the growth problems, the influence of different combinations of matrix layers on the structural and optical properties of the quantum dots was investigated in the second part of this work. The strain and bandgap of these layers were varied systematically. (orig.)

Comparative effectiveness of ACC-deaminase and/or nitrogen-fixing rhizobacteria in promotion of maize (Zea mays L.) growth under lead pollution.

Science.gov (United States)

Hassan, Waseem; Bano, Rizwana; Bashir, Farhat; David, Julie

2014-09-01

Lead (Pb) pollution is appearing as an alarming threat nowadays. Excessive Pb concentrations in agricultural soils result in minimizing the soil fertility and health which affects the plant growth and leads to decrease in crop production. Plant growth promoting rhizobacteria (PGPR) are beneficial bacteria which can protect the plants against many abiotic stresses, and enhance the growth. The study aimed to identify important rhizobacterial strains by using the 1-aminocyclopropane-1-carboxylate (ACC) enrichment technique and examine their inoculation effects in the growth promotion of maize, under Pb pollution. A pot experiment was conducted and six rhizobacterial isolates were used. Pb was added to 2 kg soil in each pot (with 4 seeds/pot) using Pb(NO3)2 at the rate of 0, 100, 200, 300, and 400 mg kg(-1) Pb with three replications in completely randomized design. Rhizobacterial isolates performed significantly better under all Pb levels, i.e., 100 to 400 Pb mg kg(-1) soil, compared to control. Comparing the efficacy of the rhizobacterial isolates under different Pb levels, rhizobacterial isolates having both ACC-deaminase and nitrogen-fixing activities (AN8 and AN12) showed highest increase in terms of the physical, chemical and enzymatic growth parameters of maize, followed by the rhizobacterial isolates having ACC-deaminase activity only (ACC5 and ACC8), and then the nitrogen-fixing rhizobia (Azotobacter and RN5). However, the AN8 isolate showed maximum efficiency, and highest shoot and root length (14.2 and 6.1 cm), seedling fresh and dry weights (1.91 and 0.14 g), chlorophyll a, b, and carotenoids (24.1, 30.2 and 77.7 μg/l), protein (0.82 mg/g), proline (3.42 μmol/g), glutathione S-transferase, peroxidase and catalase (12.3, 4.2 and 7.2 units/mg protein), while the lowest Pb uptake in the shoot and root (0.83 and 0.48 mg/kg) were observed under this rhizobial isolate at the highest Pb level (i.e., 400 Pb mg kg(-1) soil). The results revealed that PGPR

Cell surface acid-base properties of the cyanobacterium Synechococcus: Influences of nitrogen source, growth phase and N:P ratios

Science.gov (United States)

Liu, Yuxia; Alessi, D. S.; Owttrim, G. W.; Kenney, J. P. L.; Zhou, Qixing; Lalonde, S. V.; Konhauser, K. O.

2016-08-01

The distribution of many trace metals in the oceans is controlled by biological uptake. Recently, Liu et al. (2015) demonstrated the propensity for a marine cyanobacterium to adsorb cadmium from seawater, suggesting that cell surface reactivity might also play an important role in the cycling of metals in the oceans. However, it remains unclear how variations in cyanobacterial growth rates and nutrient supply might affect the chemical properties of their cellular surfaces. In this study we used potentiometric titrations and Fourier Transform Infrared (FT-IR) spectrometry to profile the key metabolic changes and surface chemical responses of a Synechococcus strain, PCC 7002, during different growth regimes. This included testing various nitrogen (N) to phosphorous (P) ratios (both nitrogen and phosphorous dependent), nitrogen sources (nitrate, ammonium and urea) and growth stages (exponential, stationary, and death phase). FT-IR spectroscopy showed that varying the growth substrates on which Synechococcus cells were cultured resulted in differences in either the type or abundance of cellular exudates produced or a change in the cell wall components. Potentiometric titration data were modeled using three distinct proton binding sites, with resulting pKa values for cells of the various growth conditions in the ranges of 4.96-5.51 (pKa1), 6.67-7.42 (pKa2) and 8.13-9.95 (pKa3). According to previous spectroscopic studies, these pKa ranges are consistent with carboxyl, phosphoryl, and amine groups, respectively. Comparisons between the titration data (for the cell surface) and FT-IR spectra (for the average cellular changes) generally indicate (1) that the nitrogen source is a greater determinant of ligand concentration than growth phase, and (2) that phosphorus limitation has a greater impact on Synechococcus cellular and extracellular properties than does nitrogen limitation. Taken together, these techniques indicate that nutritional quality during cell growth can

Simplified MPN method for enumeration of soil naphthalene degraders using gaseous substrate.

Science.gov (United States)

Wallenius, Kaisa; Lappi, Kaisa; Mikkonen, Anu; Wickström, Annika; Vaalama, Anu; Lehtinen, Taru; Suominen, Leena

2012-02-01

We describe a simplified microplate most-probable-number (MPN) procedure to quantify the bacterial naphthalene degrader population in soil samples. In this method, the sole substrate naphthalene is dosed passively via gaseous phase to liquid medium and the detection of growth is based on the automated measurement of turbidity using an absorbance reader. The performance of the new method was evaluated by comparison with a recently introduced method in which the substrate is dissolved in inert silicone oil and added individually to each well, and the results are scored visually using a respiration indicator dye. Oil-contaminated industrial soil showed slightly but significantly higher MPN estimate with our method than with the reference method. This suggests that gaseous naphthalene was dissolved in an adequate concentration to support the growth of naphthalene degraders without being too toxic. The dosing of substrate via gaseous phase notably reduced the work load and risk of contamination. The result scoring by absorbance measurement was objective and more reliable than measurement with indicator dye, and it also enabled further analysis of cultures. Several bacterial genera were identified by cloning and sequencing of 16S rRNA genes from the MPN wells incubated in the presence of gaseous naphthalene. In addition, the applicability of the simplified MPN method was demonstrated by a significant positive correlation between the level of oil contamination and the number of naphthalene degraders detected in soil.

Nitrogen cycling in a flooded-soil ecosystem planted to rice (Oryza sativa L.)

International Nuclear Information System (INIS)

Reddy, K.R.

1982-01-01

15 N studies of various aspects of the nitrogen cycle in a flooded rice ecosystem on Crowley silt loam soil in Louisiana were reviewed to construct a mass balance model of the nitrogen cycle for this system. Nitrogen transformations modeled included 1) net ammonification (0.22 mg NH 4+ -N kg dry soil - 1 day - 1 ). 2) net nitrification (207 mg NO 3- -N kg dry soil - 1 day - 1 ). 3) denitrification (0.37 mg N kg dry soil - 1 day - 1 ), and 4) biological N 2 fixation (0.16 mg N kg dry soil - 1 day - 1 ). Nitrogen inputs included 1) application of fertilizers, 2) incorporation of crop residues, 3) biological N 2 fixation, and 4) deposition. Nitrogen outputs included 1) crop removal, 2) gaseous losses from NH 3 volatilization and simultaneous occurrence of nitrification-denitrification, and 3) leaching and runoff. Mass balance calculations indicated that 33% of the available inorganic nitrogen was recovered by rice, and the remaining nitrogen was lost from the system. Losses of N due to ammonia volatilization were minimal because fertilizer-N was incorporated into the soil. A significant portion of inorganic-N was lost by ammonium diffusion from the anaerobic layer to the aerobic layer in response to a concentration gradient and subsequent nitrification in the aerobic layer followed by nitrate diffusion into the anaerobic layer and denitrification into gaseous end products. Leaching and surface runoff losses were minimal. (orig.)

Effect of Borax and cysteamine compound on finishing sheep growth performance, nitrogen retention, serum biochemical indices and body protein motabolism

International Nuclear Information System (INIS)

Chang Xinyao' Xie Hongbing; Wei Gangcai; Wang Hong

2009-01-01

Experiment was conducted to investigate the effects of borax, cysteamine and the mixture of two compounds on growth performance, serum biochemical indices, protein turn-over and nitrogen aggradation of sheep by using isotope ( 15 N-Gly) technique, nitrogen balance trial and serum testing. The results showed that both borax and cysteamine could increase the growth performance of sheep, especially the cysteamine and its mixture with borax, which increased average daily feed intake (P 3 ) and levothyroxine (T 4 ) of mixture were higher than that of control group (P<0.05), and the concentrations of growth hormone (GH) and insulin-like growth factors (IGF-1) were also significantly higher than those of control group (P<0.01). There was no significant difference of insulin (INS) between experiment groups and control group (P<0.05). Both mixture and borax contributed to increasing nitrogen retention, net nitrogen utilization, digestibility and biological value. Both borax and cysteamine accelerated protein degradation rate, apparent amino acid utilization rate and net amino acid utilization rate as well as biological value, body protein and oxidation rate, but the former was greater than the later. (authors)

Exogenous sodium sulfide improves morphological and physiological responses of a hybrid Populus species to nitrogen dioxide.

Science.gov (United States)

Hu, Yanbo; Bellaloui, Nacer; Sun, Guangyu; Tigabu, Mulualem; Wang, Jinghong

2014-06-15

Gaseous nitrogen dioxide (NO2) can disturb normal plant growth and trigger complex physiological responses. NO2-induced responses are influenced by biotic or abiotic factors. In this study, we investigated the effects of exogenous sodium sulfide (Na2S, 5mmolL(-1)) on epidermis and stomata related physico-chemical responses of hybrid poplar cuttings (Pouplus alba×P. berolinensis) to gaseous NO2 (4μl1(-1)) for three time periods (0, 14 and 48h). We also investigated hydrogen sulfide (H2S), nitrate-nitrogen and nitrate reductase activity (NR) in control and Na2S treated plants. Our results showed that NO2 exposure for 48h led to the decline of NR, maximal PSII quantum yield (Fv/Fm), net photosynthetic rate (Pn), and dark respiration rate (Rd). The maximum rate for the post-illumination carbon dioxide burst (PIB) occurred in 48-h exposed leaves 13-15s after darkening. Moreover, NO2 exposure resulted in a significant increase in nitrogen percentage (from 0 to 33%) and a decrease in the macro and micro-elements of leaf surface. Spraying Na2S aqueous solution on the leaf surfaces significantly increased the thicknesses of palisade/spongy tissue and H2S content. Na2S pretreatment alleviated NO2-caused toxic effects as indicated by increased NR and higher values of Pn, Fv/Fm, and actual photochemical efficiency in light (ФPSII) compared with the control. Na2S pretreatment had no significant impacts on PIB-based photorespiration or elements composition of a leaf surface. Copyright © 2013 Elsevier GmbH. All rights reserved.

Viral pathogen production in a wild grass host driven by host growth and soil nitrogen.

Science.gov (United States)

Whitaker, Briana K; Rúa, Megan A; Mitchell, Charles E

2015-08-01

Nutrient limitation is a basic ecological constraint that has received little attention in studies on virus production and disease dynamics. Nutrient availability could directly limit the production of viral nucleic acids and proteins, or alternatively limit host growth and thus indirectly limit metabolic pathways necessary for viral replication. In order to compare direct and indirect effects of nutrient limitation on virus production within hosts, we manipulated soil nitrogen (N) and phosphorus (P) availability in a glasshouse for the wild grass host Bromus hordeaceus and the viral pathogen Barley yellow dwarf virus-PAV. We found that soil N additions increased viral concentrations within host tissues, and the effect was mediated by host growth. Specifically, in statistical models evaluating the roles of host biomass production, leaf N and leaf P, viral production depended most strongly on host biomass, rather than the concentration of either nutrient. Furthermore, at low soil N, larger plants supported greater viral concentrations than smaller ones, whereas at high N, smaller plants supported greater viral concentrations. Our results suggest that enhanced viral productivity under N enrichment is an indirect consequence of nutrient stimulation to host growth rate. Heightened pathogen production in plants has important implications for a world facing increasing rates of nutrient deposition. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

The effects of nitrogen fixation and plant growth-promoting in rice-diazotroph association

International Nuclear Information System (INIS)

Lin Fan; Wang Lu

1999-05-01

This is a review of studies on applications of the genetic engineered ammonium-tolerant diazotroph as an inoculum with the effects of nitrogen-fixation, plant growth-promoting and yield-increasing on rice and some crops by using 15 N tracer in mini-plot and field experiments in resent years

Inhibition of tomato shoot growth by over-irrigation is linked to nitrogen deficiency and ethylene.

Science.gov (United States)

Fiebig, Antje; Dodd, Ian C

2016-01-01

Although physiological effects of acute flooding have been well studied, chronic effects of suboptimal soil aeration caused by over-irrigation of containerized plants have not, despite its likely commercial significance. By automatically scheduling irrigation according to soil moisture thresholds, effects of over-irrigation on soil properties (oxygen concentration, temperature and moisture), leaf growth, gas exchange, phytohormone [abscisic acid (ABA) and ethylene] relations and nutrient status of tomato (Solanum lycopersicum Mill. cv. Ailsa Craig) were studied. Over-irrigation slowly increased soil moisture and decreased soil oxygen concentration by 4%. Soil temperature was approximately 1°C lower in the over-irrigated substrate. Over-irrigating tomato plants for 2 weeks significantly reduced shoot height (by 25%) and fresh weight and total leaf area (by 60-70%) compared with well-drained plants. Over-irrigation did not alter stomatal conductance, leaf water potential or foliar ABA concentrations, suggesting that growth inhibition was not hydraulically regulated or dependent on stomatal closure or changes in ABA. However, over-irrigation significantly increased foliar ethylene emission. Ethylene seemed to inhibit growth, as the partially ethylene-insensitive genotype Never ripe (Nr) was much less sensitive to over-irrigation than the wild type. Over-irrigation induced significant foliar nitrogen deficiency and daily supplementation of small volumes of 10 mM Ca(NO3 )2 to over-irrigated soil restored foliar nitrogen concentrations, ethylene emission and shoot fresh weight of over-irrigated plants to control levels. Thus reduced nitrogen uptake plays an important role in inhibiting growth of over-irrigated plants, in part by stimulating foliar ethylene emission. © 2015 Scandinavian Plant Physiology Society.

EVALUATION OF GASEOUS EMISSIONS FROM THE RĂDĂUŢI MUNICIPAL LANDFILL

Directory of Open Access Journals (Sweden)

Marinela PETRESCU

2011-03-01

Full Text Available Our study presents the evaluation of gaseous emissions generated by a non-compliant municipal landfill after its closure (municipal landfill Rădăuţi. To this end we measured and interpreted the characteristics of gaseous emissions captured in two monitoring boreholes made on the deposit surface (F1 and F2. The main components of landfill gas are CH4 and CO2, and in lower proportions O2, N2 and nitrogen oxides, and also traces of H2S and CO. Their concentrations were measured using a portable gas analyzer GA type 2000Plus, which recorded simultaneously temperature and pressure data of the landfill gas. The high concentration of about 60% CH4 and approximately 39% CO2 in the landfill gas captured in two different areas (F1 and F2 shows the polluting character of those emissions with a direct impact on the environmental component "air", due to the greenhouse effect produced by those two components. Moreover, the characteristics of the measured gaseous emissions (a CH4 content above 50%, a 2-3 l / h flow rate indicates they have significant energy potential and represent a possible source of renewable energy.

The better growth phenotype of DvGS1-transgenic arabidopsis thaliana is attributed to the improved efficiency of nitrogen assimilation

Directory of Open Access Journals (Sweden)

Zhu Chenguang

2015-01-01

Full Text Available The overexpression of the algal glutamine synthetase (GS gene DvGS1 in Arabidopsis thaliana resulted in higher plant biomass and better growth phenotype. The purpose of this study was to recognize the biological mechanism for the growth improvement of DvGS1-transgenic Arabidopsis. A series of molecular and biochemical investigations related to nitrogen and carbon metabolism in the DvGS1-transgenic line was conducted. Analysis of nitrogen use efficiency (NUE-related gene transcription and enzymatic activity revealed that the transcriptional level and enzymatic activity of the genes encoding GS, glutamate synthase, glutamate dehydrogenase, alanine aminotransferase and aspartate aminotransferase, were significantly upregulated, especially from leaf tissues of the DvGS1-transgenic line under two nitrate conditions. The DvGS1-transgenic line showed increased total nitrogen content and decreased carbon: nitrogen ratio compared to wild-type plants. Significant reduced concentrations of free nitrate, ammonium, sucrose, glucose and starch, together with higher concentrations of total amino acids, individual amino acids (glutamate, aspartate, asparagine, methionine, soluble proteins and fructose in leaf tissues confirmed that the DvGS1-transgenic line demonstrated a higher efficiency of nitrogen assimilation, which subsequently affected carbon metabolism. These improved metabolisms of nitrogen and carbon conferred the DvGS1-transgenic Arabidopsis higher NUE, more biomass and better growth phenotype compared with the wild-type plants.

Bench-scale and full-scale studies of nitric oxides reduction by gaseous fuel reburning

International Nuclear Information System (INIS)

Su, S.; Xiang, J.; Sun, L.S.; Hu, S.; Zhu, J.M.

2008-01-01

Nitrogen oxides (NOx) emissions from coal-fired boilers are significant contributors to atmospheric pollution. China has specified more rigorous legal limits for NOx emissions from power plants. As a result of the need to reduce NOx emissions, cost-effective NOx reduction strategies must be explored. This paper presented detailed experimental studies on a gaseous fuel reburning process that was performed in a 36 kilowatt bench-scale down-fired furnace to define the optimal reburning operating conditions when different Chinese coals were fired in the furnace. In addition, the combustion system of a 350 megawatt full-scale boiler was retrofitted according to the experimental results. Finally, the gaseous fuel reburning was applied to the retrofitted full-scale boiler. The purpose of the study was to obtain a better understanding of the influence of the key parameters on nitric oxide (NO) reduction efficiency of the reburning process and demonstrate the gaseous fuel reburning on a 350 MWe coal-fired boiler in China. The paper described the experimental procedure with particular reference to the experimental facility and measurement; a schematic diagram of the experimental system; experimental fuels; and characteristics of coals for the reburning experiments. Results that were presented included influence of reburn zone residence time; influence of gaseous reburn fuel per cent; influence of excess air coefficient; and unburned carbon in fly ash. It was concluded that both an above 50 per cent NO reduction efficiency and low carbon loss can be obtained by the gaseous fuel reburning process under the optimal operating conditions. 20 refs., 5 tabs., 10 figs

Growth analysis partitioning of assimilate in tomato plants cv. Micro-Tom submitted to nitrogen and pyraclostrobin

Directory of Open Access Journals (Sweden)

Emanuela Garbin Martinazzo

2015-10-01

Full Text Available This work aimed at comparing the growth and partitioning of assimilate in tomato plants cv. Micro-Tom subjected to nitrogen and pyraclostrobin. This substance favors the development of chloroplasts and the synthesis of chlorophyll. Tomato plants were submitted to the treatments: T1, complete nutrient solution without pyraclostrobin, T2, complete nutrient solution + pyraclostrobin, T3, ½ strength nutrient solution without N pyraclostrobin and T4, ½ strength nutrient solution N + pyraclostrobin. Plants were collected at regular intervals of seven days after transplantation throughout the crop cycle, with dry mass and leaf area being determined. From the primary data, growth analysis was carried out to calculate total dry matter (Wt, the instantaneous rates of dry matter production (Ct, relative growth (Rw e net assimilation (Ea, leaf area (Af, production rates (Ca and relative growth of leaf area index (Ra and leaf weight (Fw specific leaf area (Sa the dry matter partitioning between organs and number (Nfr and fresh fruit weight (Wfr. Plants of T1 showed higher Wt, Ct and Wfr compared to those of other treatments. However, the T2 plants exhibited similar Nfr to T1 plants, being superior to others. Also allocated on the total dry matter and at the end of the cycle, a higher percentage of dry matter in the seafood compared to T3 and T4 plants. Also they allocated relative to the total dry matter and at the end of the cycle, a higher percentage in fruits of plants to T3 and T4. The association between nitrogen and pyraclostrobin changes the growth and assimilated partition on tomato plants cv. Micro – Tom, and those submitted to ½ dose of nitrogen have a higher total dry matter and less final percentage of total dry matter in fruits , comparatively to those submitted to the association ½ dose of nitrogen and pyraclostrobin.

Enhancement of soybean (Glycine max L.) growth by bio-fertilizers of Nostoc muscorum and Nostoc rivulare

International Nuclear Information System (INIS)

Sholkamy, E.N.; Komy, H.M.E.

2015-01-01

In the present study the nitrogenase activity of Nostoc muscorum and Nostoc rivulare was evaluated in vitro; the test showed that Nostoc muscorum and Nostoc rivulare have the ability to fix nitrogen. In a pot experiment under field conditions, the results of the present study showed that inoculation of the soybean plant with Nostoc muscorum and Nostoc rivulare, either alone or in combination with N-fertilizer at 50 and 100 kg N/ha, caused a significant increase in the growth of these plants, as reflected in plant height, leaf area, weight of plant as well as the legume weight of soybeans. The combination of biofertilization and N-fertilization, especially at 100 kg N/ha, had more effect on both the growth of soybeans and nitrogenase activity compared to biofertilization alone. Nostoc muscorum and Nostoc rivulare are a promising biofertilizers for achieving an efficient association between N2 fixing cyanobacteria and soybeans; and thus enhancement of the growth. (author)

Growth responses of Neurospora crassa to increased partial pressures of the noble gases and nitrogen.

Science.gov (United States)

Buchheit, R G; Schreiner, H R; Doebbler, G F

1966-02-01

Buchheit, R. G. (Union Carbide Corp., Tonawanda, N.Y.), H. R. Schreiner, and G. F. Doebbler. Growth responses of Neurospora crassa to increased partial pressures of the noble gases and nitrogen. J. Bacteriol. 91:622-627. 1966.-Growth rate of the fungus Neurospora crassa depends in part on the nature of metabolically "inert gas" present in its environment. At high partial pressures, the noble gas elements (helium, neon, argon, krypton, and xenon) inhibit growth in the order: Xe > Kr> Ar > Ne > He. Nitrogen (N(2)) closely resembles He in inhibitory effectiveness. Partial pressures required for 50% inhibition of growth were: Xe (0.8 atm), Kr (1.6 atm), Ar (3.8 atm), Ne (35 atm), and He ( approximately 300 atm). With respect to inhibition of growth, the noble gases and N(2) differ qualitatively and quantitatively from the order of effectiveness found with other biological effects, i.e., narcosis, inhibition of insect development, depression of O(2)-dependent radiation sensitivity, and effects on tissue-slice glycolysis and respiration. Partial pressures giving 50% inhibition of N. crassa growth parallel various physical properties (i.e., solubilities, solubility ratios, etc.) of the noble gases. Linear correlation of 50% inhibition pressures to the polarizability and of the logarithm of pressure to the first and second ionization potentials suggests the involvement of weak intermolecular interactions or charge-transfer in the biological activity of the noble gases.

Temperature sensitivity of nitrogen productivity

OpenAIRE

Ladanai, Svetlana; Ågren, Göran

2002-01-01

Environmental conditions control physiological processes in plants and thus their growth. The predicted global warming is expected to accelerate tree growth. However, the growth response is a complex function of several processes. To circumvent this problem we have used the nitrogen productivity (dry matter production per unit of nitrogen in the plant), which is an aggregate parameter. Data on needle dry matter, production, and nitrogen content in needles of Scots pine (Pinus sylvestris) from...

Trimethylamine and trimethylamine N-oxide are supplementary energy sources for a marine heterotrophic bacterium: implications for marine carbon and nitrogen cycling.

Science.gov (United States)

Lidbury, Ian D E A; Murrell, J Colin; Chen, Yin

2015-03-01

Bacteria of the marine Roseobacter clade are characterised by their ability to utilise a wide range of organic and inorganic compounds to support growth. Trimethylamine (TMA) and trimethylamine N-oxide (TMAO) are methylated amines (MA) and form part of the dissolved organic nitrogen pool, the second largest source of nitrogen after N2 gas, in the oceans. We investigated if the marine heterotrophic bacterium, Ruegeria pomeroyi DSS-3, could utilise TMA and TMAO as a supplementary energy source and whether this trait had any beneficial effect on growth. In R. pomeroyi, catabolism of TMA and TMAO resulted in the production of intracellular ATP which in turn helped to enhance growth rate and growth yield as well as enhancing cell survival during prolonged energy starvation. Furthermore, the simultaneous use of two different exogenous energy sources led to a greater enhancement of chemoorganoheterotrophic growth. The use of TMA and TMAO primarily as an energy source resulted in the remineralisation of nitrogen in the form of ammonium, which could cross feed into another bacterium. This study provides greater insight into the microbial metabolism of MAs in the marine environment and how it may affect both nutrient flow within marine surface waters and the flux of these climatically important compounds into the atmosphere.

Terrestrial nitrogen cycles: Some unanswered questions

Science.gov (United States)

Vitousek, P.

1984-01-01

Nitrogen is generally considered to be the element which most often limits the growth of plants in both natural and agricultural ecosystems. It regulates plant growth because photosynthetic rates are strongly dependent on the concentration of nitrogen in leaves, and because relatively large mounts of protein are required for cell division and growth. Yet nitrogen is abundant in the biosphere - the well-mixed pool in the atmosphere is considered inexhaustible compared to biotic demand, and the amount of already fixed organic nitrogen in soils far exceeds annual plant uptake in terrestrial ecosystems. In regions where natural vegetation is not nitrogen limited, continuous cultivation induces nitrogen deficiency. Nitrogen loss from cultivated lands is more rapid than that of other elements, and nitrogen fertilization is generally required to maintain crop yield under any continuous system. The pervasiveness of nitrogen deficiency in many natural and most managed sites is discussed.

Rapid monitoring of intermediate states and mass balance of nitrogen during denitrification by means of cavity enhanced Raman multi-gas sensing

Energy Technology Data Exchange (ETDEWEB)

Keiner, Robert [Institute of Physical Chemistry, Friedrich Schiller University Jena, Jena 07743 (Germany); Leibniz Institute of Photonic Technology, Jena 07745 (Germany); Herrmann, Martina; Küsel, Kirsten [Institute of Ecology, Friedrich Schiller University Jena, Jena 07743 (Germany); German Centre for Integrative Biodiversity Research (iDiv) Halle–Jena–Leipzig, Leipzig 04103 (Germany); Popp, Jürgen [Institute of Physical Chemistry, Friedrich Schiller University Jena, Jena 07743 (Germany); Leibniz Institute of Photonic Technology, Jena 07745 (Germany); InfectoGnostics Forschungscampus, Zentrum für Angewandte Forschung, Jena 07743 (Germany); Abbe School of Photonics, Friedrich Schiller University, Jena (Germany); Frosch, Torsten, E-mail: torsten.frosch@uni-jena.de [Institute of Physical Chemistry, Friedrich Schiller University Jena, Jena 07743 (Germany); Leibniz Institute of Photonic Technology, Jena 07745 (Germany); InfectoGnostics Forschungscampus, Zentrum für Angewandte Forschung, Jena 07743 (Germany)

2015-03-15

Highlights: • CERS is a versatile new analytical methodology. • Continuous online quantification of reduction of {sup 15}N-labelled nitrate by P. stutzeri was demonstrated. • The total nitrogen element budget was monitored online for the first time. • Sterile online acquisition of the pH changes in the P. stutzeri culture was demonstrated. • An increased slope of the pH value coincided with a temporary accumulation of N{sub 2}O. - Abstract: The comprehensive investigation of changes in N cycling has been challenging so far due to difficulties with measuring gases such as N{sub 2} and N{sub 2}O simultaneously. In this study we introduce cavity enhanced Raman gas spectroscopy as a new analytical methodology for tracing the stepwise reduction of {sup 15}N-labelled nitrate by the denitrifying bacteria Pseudomonas stutzeri. The unique capabilities of Raman multi-gas analysis enabled real-time, continuous, and non-consumptive quantification of the relevant gases ({sup 14}N{sub 2}, {sup 14}N{sub 2}O, O{sub 2}, and CO{sub 2}) and to trace the fate of {sup 15}N-labeled nitrate substrate ({sup 15}N{sub 2}, {sup 15}N{sub 2}O) added to a P. stutzeri culture with one single measurement. Using this new methodology, we could quantify the kinetics of the formation and degradation for all gaseous compounds (educts and products) and thus study the reaction orders. The gas quantification was complemented with the analysis of nitrate and nitrite concentrations for the online monitoring of the total nitrogen element budget. The simultaneous quantification of all gases also enabled the contactless and sterile online acquisition of the pH changes in the P. stutzeri culture by the stoichiometry of the redox reactions during denitrification and the CO{sub 2}-bicarbonate equilibrium. Continuous pH monitoring – without the need to insert an electrode into solution – elucidated e.g. an increase in the slope of the pH value coinciding with an accumulation of nitrite, which in

Effects of growth reducer and nitrogen fertilization on morphological variables, SPAD index, interception of radiation and productivity of wheat

OpenAIRE

Elvis Felipe Elli; Braulio Otomar Caron; Sandro Luis Petter Medeiros; Elder Eloy; Gean Charles Monteiro; Denise Schmidt

2015-01-01

ABSTRACT The objective of this study was to evaluate the effect of growth reducer and nitrogen fertilization on morphological variables, SPAD index, radiation interception, and grain yield of three cultivars of wheat. The experimental design was a randomized block in factorial scheme 3x5x2, with three cultivars (Mestre, Iguaçú and Itaipú), five nitrogen doses (0, 40, 80, 120, 160 Kg ha-1), and application or no application of a growth reducer, with three replications. The following characteri...

Resonantly enhanced production of excited fragments of gaseous molecules following core-level excitation

International Nuclear Information System (INIS)

Chen, J.M.; Lu, K.T.; Lee, J.M.; Ho, S.C.; Chang, H.W.; Lee, Y.Y.

2005-01-01

State-selective dissociation dynamics for the excited fragments of gaseous Si(CH 3 ) 2 Cl 2 following Cl 2p and Si 2p core-level excitations have been investigated by resonant photoemission spectroscopy and dispersed UV/optical fluorescence spectroscopy. The main features in the gaseous Si(CH 3 ) 2 Cl 2 fluorescence spectrum are identified as the emission from excited Si*, Si + *, CH* and H*. The core-to-Rydberg excitations at both Si 2p and Cl 2p edges lead to a noteworthy production of not only the excited atomic fragments, neutral and ionic (Si*, Si + *) but also the excited diatomic fragments (CH*). In particular, the excited neutral atomic fragments Si* are significantly reinforced. The experimental results provide deeper insight into the state-selective dissociation dynamics for the excited fragments of molecules via core-level excitation

Nitrogen evolution during rapid hydropyrolysis of coal

Energy Technology Data Exchange (ETDEWEB)

Xu, W.-C.; Kumagai, M. [Institute of Research and Innovation, Kashiwa (Japan)

2002-12-01

The behavior of nitrogen evolution during rapid hydropyrolysis of coal has been investigated at temperatures ranging from 923 to 1123 K and hydrogen pressure up to 5 MPa using a continuous free fall pyrolyzer. Three coals have been tested in this study. The dominant nitrogen gaseous species is ammonia, together with a little amount of HCN because most of HCN is converted to NH{sub 3} through secondary reactions. The results show that the evolution of nitrogen in coal is caused mainly by devolatilization at temperatures below 973 K, while the evolution of volatile nitrogen in char is accelerated with increasing temperature and hydrogen pressure. The mineral matter in coal act as catalysts to promote the evolution of volatile nitrogen in char to N{sub 2} apparently at high temperatures of 1123 K, as found during pyrolysis of coal by Ohtsuka et al. A pseudo-first-order kinetic model was applied to the evolution of nitrogen in coal during rapid hydropyrolysis. The model shows the activation energy for the nitrogen evolution from coal is 36.6 58.6 kJ/mol while the rate of the nitrogen evolution depends on hydrogen pressure in the order of 0.16 0.24. 41 refs., 11 figs., 3 tabs.

Functional role of bacteria from invasive Phragmites australis in promotion of host growth

Science.gov (United States)

Soares, M. A.; Li, H-Y; Kowalski, Kurt P.; Bergen, M.; Torres, M. S.; White, J. F.

2016-01-01

We hypothesize that bacterial endophytes may enhance the competitiveness and invasiveness of Phragmites australis. To evaluate this hypothesis, endophytic bacteria were isolated from P. australis. The majority of the shoot meristem isolates represent species from phyla Firmicutes, Proteobacteria, and Actinobacteria. We chose one species from each phylum to characterize further and to conduct growth promotion experiments in Phragmites. Bacteria tested include Bacillus amyloliquefaciens A9a, Achromobacter spanius B1, and Microbacterium oxydans B2. Isolates were characterized for known growth promotional traits, including indole acetic acid (IAA) production, secretion of hydrolytic enzymes, phosphate solubilization, and antibiosis activity. Potentially defensive antimicrobial lipopeptides were assayed for through application of co-culturing experiments and mass spectrometer analysis. B. amyloliquefaciens A9a and M. oxydans B2 produced IAA. B. amyloliquefaciens A9a secreted antifungal lipopeptides. Capability to promote growth of P. australis under low nitrogen conditions was evaluated in greenhouse experiments. All three isolates were found to increase the growth of P. australis under low soil nitrogen conditions and showed increased absorption of isotopic nitrogen into plants. This suggests that the Phragmites microbes we evaluated most likely promote growth of Phragmites by enhanced scavenging of nitrogenous compounds from the rhizosphere and transfer to host roots. Collectively, our results support the hypothesis that endophytic bacteria play a role in enhancing growth of P. australis in natural populations. Gaining a better understanding of the precise contributions and mechanisms of endophytes in enabling P. australis to develop high densities rapidly could lead to new symbiosis-based strategies for management and control of the host.

Quantitative determination of heavy nitrogen by spectroscopy

International Nuclear Information System (INIS)

Kumazawa, Kikuo

1974-01-01

Explanation is made on the merits of the determination with heavy nitrogen, the principle and apparatus used for the determination, the method of production of discharge tubes, and the application of the method to several special cases. The spectra belonging to the 2nd positive system are used for the analysis of heavy nitrogen by emission spectroscopy. The spectra near 2980 A are used most often. The bandheads utilizable for the determination are 2976.8 for 14 N 2 , 2982.9 for 14 N 15 N, and 2988.6 A for 15 N 2 , respectively. The sample must be sealed in a discharge tube as nitrogen gas, at first. Mixing of impurities lowers the sensitivity of the determination. The gas pressure is adjusted 10 1-6 Torr. The preparation of gaseous nitrogen is made by either the Rittenberg or the Dumas method. When the amount of a given sample is more than 50 mg, and nitrogen is present as ammonium salt, NH 3 is converted to nitrogen by the reaction with sodium hypobromite. When nitrogen is not present as ammonium salt, Dumas' method is adopted. The amount of heavy nitrogen in the aminoacid separated by thin layer chromatography with silica gel was successfully determined by this method. Simultaneous determination of heavy nitrogen and total nitrogen was also possible by this method. (Fukutomi, T.)

Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy

Energy Technology Data Exchange (ETDEWEB)

Gunning, Brendan P.; Clinton, Evan A.; Merola, Joseph J.; Doolittle, W. Alan, E-mail: alan.doolittle@ece.gatech.edu [Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Bresnahan, Rich C. [Veeco Instruments, St. Paul, Minnesota 55127 (United States)

2015-10-21

Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N{sub 2} while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N{sub 2} and 7.7 sccm Ar flows at 600 W radio frequency power, for which the standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 10{sup 16} to 3.8 × 10{sup 19} cm{sup −3} were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1–2 × 10{sup 15} cm{sup −3}. The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be

Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy

International Nuclear Information System (INIS)

Gunning, Brendan P.; Clinton, Evan A.; Merola, Joseph J.; Doolittle, W. Alan; Bresnahan, Rich C.

2015-01-01

Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N 2 while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N 2 and 7.7 sccm Ar flows at 600 W radio frequency power, for which the standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 10 16 to 3.8 × 10 19 cm −3 were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1–2 × 10 15 cm −3 . The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be addressed. Nonetheless, the

Nitrogen-responsive genes are differentially regulated in planta during Fusarium oxyspsorum f. sp. lycopersici infection.

Science.gov (United States)

Divon, Hege H; Rothan-Denoyes, Beatrice; Davydov, Olga; DI Pietro, Antonio; Fluhr, Robert

2005-07-01

SUMMARY Nitrogen is an essential growth component whose availability will limit microbial spread, and as such it serves as a key control point in dictating an organism's adaptation to various environments. Little is known about fungal nutrition in planta. To enhance our understanding of this process we examined the transcriptional adaptation of Fusarium oxysporum f. sp. lycopersici, the causal agent for vascular wilt in tomato, during nutritional stress and plant colonization. Using RT-PCR and microarray technology we compared fungal gene expression in planta to axenic nitrogen starvation culture. Several expressed sequence tags, representing at least four genes, were identified that are concomitantly induced during nitrogen starvation and in planta growth. Three of these genes show similarity to a general amino acid permease, a peptide transporter and an uricase, all functioning in organic nitrogen acquisition. We further show that these genes represent a distinguishable subset of the nitrogen-responsive transcripts that respond to amino acids commonly available in the plant. Our results indicate that nitrogen starvation partially mimics in planta growth conditions, and further suggest that minute levels of organic nitrogen sources dictate the final outcome of fungal gene expression in planta. The nature of the identified transcripts suggests modes of nutrient uptake and survival for Fusarium during colonization.

Response of Nodularia spumigena to pCO2 – Part 1: Growth, production and nitrogen cycling

Directory of Open Access Journals (Sweden)

M. Nausch

2012-08-01

Full Text Available Heterocystous cyanobacteria of the genus Nodularia form extensive blooms in the Baltic Sea and contribute substantially to the total annual primary production. Moreover, they dispense a large fraction of new nitrogen to the ecosystem when inorganic nitrogen concentration in summer is low. Thus, it is of ecological importance to know how Nodularia will react to future environmental changes, in particular to increasing carbon dioxide (CO2 concentrations and what consequences there might arise for cycling of organic matter in the Baltic Sea. Here, we determined carbon (C and dinitrogen (N2 fixation rates, growth, elemental stoichiometry of particulate organic matter and nitrogen turnover in batch cultures of the heterocystous cyanobacterium Nodularia spumigena under low (median 315 μatm, mid (median 353 μatm, and high (median 548 μatm CO2 concentrations. Our results demonstrate an overall stimulating effect of rising pCO2 on C and N2 fixation, as well as on cell growth. An increase in pCO2 during incubation days 0 to 9 resulted in an elevation in growth rate by 84 ± 38% (low vs. high pCO2 and 40 ± 25% (mid vs. high pCO2, as well as in N2 fixation by 93 ± 35% and 38 ± 1%, respectively. C uptake rates showed high standard deviations within treatments and in between sampling days. Nevertheless, C fixation in the high pCO2 treatment was elevated compared to the other two treatments by 97% (high vs. low and 44% (high vs. mid at day 0 and day 3, but this effect diminished afterwards. Additionally, elevation in carbon to nitrogen and nitrogen to phosphorus ratios of the particulate biomass formed (POC : POP and PON : POP was observed at high pCO2. Our findings suggest that rising pCO2 stimulates the growth of heterocystous diazotrophic cyanobacteria, in a similar way as reported for the non-heterocystous diazotroph Trichodesmium. Implications for biogeochemical cycling and food web dynamics, as well as ecological and socio-economical aspects in the

Nitrogen deposition outweighs climatic variability in driving annual growth rate of canopy beech trees: Evidence from long-term growth reconstruction across a geographic gradient.

Science.gov (United States)

Gentilesca, Tiziana; Rita, Angelo; Brunetti, Michele; Giammarchi, Francesco; Leonardi, Stefano; Magnani, Federico; van Noije, Twan; Tonon, Giustino; Borghetti, Marco

2018-07-01

In this study, we investigated the role of climatic variability and atmospheric nitrogen deposition in driving long-term tree growth in canopy beech trees along a geographic gradient in the montane belt of the Italian peninsula, from the Alps to the southern Apennines. We sampled dominant trees at different developmental stages (from young to mature tree cohorts, with tree ages spanning from 35 to 160 years) and used stem analysis to infer historic reconstruction of tree volume and dominant height. Annual growth volume (G V ) and height (G H ) variability were related to annual variability in model simulated atmospheric nitrogen deposition and site-specific climatic variables, (i.e. mean annual temperature, total annual precipitation, mean growing period temperature, total growing period precipitation, and standard precipitation evapotranspiration index) and atmospheric CO 2 concentration, including tree cambial age among growth predictors. Generalized additive models (GAM), linear mixed-effects models (LMM), and Bayesian regression models (BRM) were independently employed to assess explanatory variables. The main results from our study were as follows: (i) tree age was the main explanatory variable for long-term growth variability; (ii) GAM, LMM, and BRM results consistently indicated climatic variables and CO 2 effects on G V and G H were weak, therefore evidence of recent climatic variability influence on beech annual growth rates was limited in the montane belt of the Italian peninsula; (iii) instead, significant positive nitrogen deposition (N dep ) effects were repeatedly observed in G V and G H ; the positive effects of N dep on canopy height growth rates, which tended to level off at N dep values greater than approximately 1.0 g m -2  y -1 , were interpreted as positive impacts on forest stand above-ground net productivity at the selected study sites. © 2018 John Wiley & Sons Ltd.

Fertilizers nitrogen balance under maizl and winter rye in lysimentric experiments

International Nuclear Information System (INIS)

Ionova, O.N.

1979-01-01

The balance of the labelled 15 N nitrogen fertilizers in lysimentric experiment carried oUt in the turf-podsolic medium loamy soil has been studied. The results of two year experiment (1976-1977) have shown that depending on the doses and time of introduction the use of fertilizer nitrogen by maize varied from 51 to 58 % and by winter rye from 52 to 59 %. Consolidation in the organic substance of soil constituted 18-26 and 17-33 %, respectively. The losses of fertilizer nitrogen varied (14-29 % under maize and 9-23 % under winter rye). Nitrogen losses as a result of atmospheric precipitation infiltration both under maize and winter rye occured mainly at the expense of nitrogen of soil and reached considerable dimensions (31 kg) only under conditions of exceeding moistening of 1976. The losses of fertilizer nitrogen caused by washing out do not exceed 1 % for two years. The main losses of fertilizer nitrogen occurred in the form of gaseous nitrogen compounds

On the effect of pre-oxidation on the nitriding kinetics

DEFF Research Database (Denmark)

Friehling, Peter Bernhard; Somers, Marcel A. J.

2000-01-01

The oxidation of ferritic surfaces prior to gaseous nitriding has been reported to lead to improved uniformity of the compound layer thickness and enhanced nitriding kinetics. The present work considers the nucleation and growth of a model compound layer on pure iron and, using previous...... experimental and theoretical work reported in the literature, puts forward two hypotheses to explain the effects of pre-oxidation on compound layer formation. It is proposed that the nucleation of iron nitrides is enhanced by the presence of an iron-oxide layer and that the growth of an iron-nitride layer...... proceeds faster after pre-oxidation, due to a higher nitrogen content in the part of the compound layer closest to the surface....

Effects of substrate type on plant growth and nitrogen and nitrate concentration in spinach

Science.gov (United States)

The effects of three commercial substrates (a mixture of forest residues, composted grape husks, and white peat; black peat; and coir) on plant growth and nitrogen (N) and nitrate (NO3) concentration and content were evaluated in spinach (Spinacia oleracea L. cv. Tapir). Spinach seedlings were trans...

EURODIF: the uranium enrichment by gaseous diffusion

International Nuclear Information System (INIS)

Rougeau, J.P.

1981-01-01

During the seventies the nuclear power programme had an extremely rapid growth rate which entailed to increase the world uranium enrichment capacity. EURODIF is the largest undertaking in this field. This multinational joint venture built and now operates and enrichment plant using the gaseous diffusion process at Tricastin (France). This plant is delivering low enriched uranium since two years and has contracted about 110 million SWU's till 1990. Description, current activity and prospects are given in the paper. (Author) [pt

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.

Stress corrosion cracking of an uranium-6 weight per cent niobium in gaseous oxygen, nitrogen and hydrogen

International Nuclear Information System (INIS)

Brunet, H.

1989-01-01

Stress corrosion cracking (SCC) of uranium-6 weight per cent niobium alloy is studied in gaseous oxygen at room temperature (for pressures between 4.10 -7 and 0.15MPa) and 100 0 C (pressure of 0.15 MPa) and in gaseous hydrogen (for pressures between 10 -6 and 0.15 MPa). SCC map and cracking kinetics are determined as fonctions of stress-intensity factor, pressure and temperature. For oxygen, temperature seems to have no effect on the alloy embrittlement within the range of this study but the pressure influence is more complex. At room temperature, hydrogen pressure less than 0.15 MPa has no influence on the cracking kinetics. For a pressure of 0.15 MPa, fracture occurs by hydriding reaction. Complementary analyses on fracture surfaces lead to propose different mechanics responsible for cracking kinetics in these environments [fr

Enhancement of intestinal growth in neonatal rats by epidermal growth factor in milk

International Nuclear Information System (INIS)

Berseth, C.L.

1987-01-01

Breast milk has been shown to enhance neonatal intestinal growth. Because epidermal growth factor (EGF) is present in the milk of various mammalian species, the hypothesis was tested that EGF in rodent milk mediates, in part, the breast milk-enhanced intestinal growth in neonatal rat. Fifty-eight rat pups fed artificial formal that contained 1.2, 3.0, and 6.0 μg/ml EGF for 39 h had greater incorporation of [ 3 H]thymidine into DNA and DNA content of intestine than 29 pups fed unsupplemented formula. Pups fed EGF for 5 days had significantly greater body weight, intestinal weight, length, and DNA content than control pups. Conversely, pups fed pooled rat milk containing rabbit-derived antibody to EGF for 39 h had intestines of lower weight that contained less DNA than animals fed rat milk containing normal rabbit serum. EGF appears to mediate, in part, breast milk-enhanced neonatal intestinal growth

The origin of the enhanced performance of nitrogen-doped MoS_2 in lithium ion batteries

International Nuclear Information System (INIS)

Liu, Qiuhong; Weijun, Xia; Wu, Zhenjun; Huo, Jia; Liu, Dongdong; Wang, Shuangyin; Wang, Qiang

2016-01-01

MoS_2 with a similar layered structure to graphene has been widely applied in various areas including lithium ion batteries. However, low conductivity, capacity fading and poor rate performance are still the main challenges for MoS_2 anode materials. In this work, for the first time, we prepared nitrogen-doped MoS_2 (N-MoS_2) nanosheets through a simple two-step method involving the preparation of MoS_2 with defects by the hydrothermal method, followed by sintering in a NH_3 atmosphere. Our electrochemical characterizations and density functional theory calculations demonstrated that nitrogen doping could enhance the electron conductivity and showed higher specific capacity than pristine MoS_2 as anode materials of lithium ion batteries, which can be attributed to the faster transportation of electrons and ions because of nitrogen doping. This work helps us understand the origin of the enhanced performance of N-doped MoS_2 in lithium ion batteries. (paper)

Method to reduce the nitrogen oxide content of gaseous wastes

Energy Technology Data Exchange (ETDEWEB)

Klopp, G.; Sueto, J.; Szasz, K.; Szebenyi, I.; Winkler, G.; Machacs, M.; Palmai, G.

1980-11-13

The proposed process is suited for the denitrification of waste gases from nitric acid plants. It proceeds without an additional energy source with an integrated adsorption unit which guaranties the complete recirculation of the produced nitrogen oxides and allows the regeneration of the adsorbents by the use of the energy from the oxidation of nitrous oxide to nitric oxide. The desorption is carried out by the intermediate passage of the hot gases from the oxidizer through the adsorber.

Effects of inorganic nitrogen forms on growth, morphology, nitrogen uptake capacity and nutrient allocation of four tropical aquatic macrophytes (Salvinia cucullata, Ipomoea aquatica, Cyperus involucratus and Vetiveria zizanioides)

DEFF Research Database (Denmark)

Jampeetong, Arunothai; Brix, Hans; Kantawanichkul, Suwasa

2012-01-01

This study assesses the growth and morphological responses, nitrogen uptake and nutrient allocation in four aquatic macrophytes when supplied with different inorganic nitrogen treatments (1) NH4+, (2) NO3−, or (3) both NH4+ and NO3−. Two free-floating species (Salvinia cucullata Roxb. ex Bory...... and Ipomoea aquatica Forssk.) and two emergent species (Cyperus involucratus Rottb. and Vetiveria zizanioides (L.) Nash ex Small) were grown with these N treatments at equimolar concentrations (500 M). Overall, the plants responded well to NH4+. Growth as RGR was highest in S. cucullata (0.12±0.003 d−1......) followed by I. aquatica (0.035 ±0.002 d−1), C. involucratus (0.03±0.002 d−1) and V. zizanioides (0.02±0.003 d−1). The NH4+ uptake rate was significantly higher than the NO3− uptake rate. The free-floating species had higher nitrogen uptake rates than the emergent species. The N-uptake rate differed between...

Microarray and growth analyses identify differences and similarities of early corn response to weeds, shade, and nitrogen stress

Science.gov (United States)

Weed interference with crop growth is often attributed to water, nutrient, or light competition; however, specific physiological responses to these stresses are not well described. This study’s objective was to compare growth, yield, and gene expression responses of corn to nitrogen (N), low light (...

Effects of vermicompost and nitrogen fertilizers on growth of Jimson weed (Datura stramonium L. as a medicinal plant

Directory of Open Access Journals (Sweden)

Ramin Abbaspour

2016-05-01

Full Text Available An experiment was conducted in order to evaluate the effect of organic (3 and 6 ton/ha vermicompost and chemical (150 and 300 kg/ha nitrogen fertilizers on growth, seed dispersal and heteroblasty of jimson weed at green house of Shiraz University in 2012. The results showed that the highest and the lowest plant growth, seed production and seed dispersal was in 300 kg/ha N and 6 ton/ha vermicompost, respectively. Position of the seeds on maternal plant had an important influence on the emergence percentage. Seeds on the middle and lowest parts of the plants had less emergence percentage compared with those on the higher parts. In general, application of 300 kg/ha nitrogen accelerated the growth of jimson weed and increase dispersal and heteroblasty of the jimson seed.

Plant allometry, leaf nitrogen and phosphorus stoichiometry, and interspecific trends in annual growth rates.

Science.gov (United States)

Niklas, Karl J

2006-02-01

Life forms as diverse as unicellular algae, zooplankton, vascular plants, and mammals appear to obey quarter-power scaling rules. Among the most famous of these rules is Kleiber's (i.e. basal metabolic rates scale as the three-quarters power of body mass), which has a botanical analogue (i.e. annual plant growth rates scale as the three-quarters power of total body mass). Numerous theories have tried to explain why these rules exist, but each has been heavily criticized either on conceptual or empirical grounds. N,P-STOICHIOMETRY: Recent models predicting growth rates on the basis of how total cell, tissue, or organism nitrogen and phosphorus are allocated, respectively, to protein and rRNA contents may provide the answer, particularly in light of the observation that annual plant growth rates scale linearly with respect to standing leaf mass and that total leaf mass scales isometrically with respect to nitrogen but as the three-quarters power of leaf phosphorus. For example, when these relationships are juxtaposed with other allometric trends, a simple N,P-stoichiometric model successfully predicts the relative growth rates of 131 diverse C3 and C4 species. The melding of allometric and N,P-stoichiometric theoretical insights provides a robust modelling approach that conceptually links the subcellular 'machinery' of protein/ribosomal metabolism to observed growth rates of uni- and multicellular organisms. Because the operation of this 'machinery' is basic to the biology of all life forms, its allometry may provide a mechanistic explanation for the apparent ubiquity of quarter-power scaling rules.

Decomposition kinetics of expanded austenite with high nitrogen contents

DEFF Research Database (Denmark)

Christiansen, Thomas; Somers, Marcel A. J.

2006-01-01

This paper addresses the decomposition kinetics of synthesized homogeneous expanded austenite formed by gaseous nitriding of stainless steel AISI 304L and AISI 316L with nitrogen contents up to 38 at.% nitrogen. Isochronal annealing experiments were carried out in both inert (N2) and reducing (H2......) atmospheres. Differential thermal analysis (DTA) and thermogravimetry were applied for identification of the decomposition reactions and X-ray diffraction analysis was applied for phase analysis. CrN precipitated upon annealing; the activation energies are 187 kJ/mol and 128 kJ/mol for AISI 316L and AISI 304L...

Combined inoculation of Pseudomonas fluorescens and Trichoderma harzianum for enhancing plant growth of vanilla (Vanilla planifolia).

Science.gov (United States)

Sandheep, A R; Asok, A K; Jisha, M S

2013-06-15

This study was conducted to evaluate the plant growth promoting efficiency of combined inoculation of rhizobacteria on Vanilla plants. Based on the in vitro performance of indigenous Trichoderma spp. and Pseudomonas spp., four effective antagonists were selected and screened under greenhouse experiment for their growth enhancement potential. The maximum percentage of growth enhancement were observed in the combination of Trichoderma harzianum with Pseudomonas fluorescens treatment followed by Pseudomonas fluorescens, Trichoderma harzianum, Pseudomonas putida and Trichoderma virens, respectively in decreasing order. Combined inoculation of Trichoderma harzianum and Pseudomonas fluorescens registered the maximum length of vine (82.88 cm), highest number of leaves (26.67/plant), recorded the highest fresh weight of shoots (61.54 g plant(-1)), fresh weight of roots (4.46 g plant(-1)) and dry weight of shoot (4.56 g plant(-1)) where as the highest dry weight of roots (2.0806 g plant(-1)) were achieved with treatments of Pseudomonas fluorescens. Among the inoculated strains, combined inoculation of Trichoderma harzianum and Pseudomonas fluorescens recorded the maximum nitrogen uptake (61.28 mg plant(-1)) followed by the combined inoculation of Trichoderma harzianum (std) and Pseudomonas fluorescens (std) (55.03 mg plant(-1)) and the highest phosphorus uptake (38.80 mg plant(-1)) was recorded in dual inoculation of Trichoderma harzianum and Pseudomonas fluorescens.

Conversion of sulfur and nitrogen oxides in air under exposure to microsecond electron beams

International Nuclear Information System (INIS)

Denisov, G.V.; Kuznetsov, D.L.; Novoselov, Yu.N.; Tkachenko, R.M.

2002-01-01

Flue gases of power plants realizing sulfur and nitrogen oxides into the atmosphere represent one of the environmental pollution sources. Paper presents the results of experimental investigations of conversion of sulfur and nitrogen oxides in the ionized gas mixture simulating composition of off-gases of thermal power stations. Pulse beam of microsecond duration electrons was used as a source of ionization. Mutual influence of both types of oxides on process of their conversion is shown. One studied possible kinetic mechanisms to remove sulfur and nitrogen oxides from gaseous mixture [ru

[Coupling effects of periodic rewatering after drought stress and nitrogen fertilizer on growth and water and nitrogen productivity of Coffea arabica].

Science.gov (United States)

Hao, Kun; Liu, Xiao Gang; Zhang, Yan; Han, Zhi Hui; Yu, Ning; Yang, Qi Liang; Liu, Yan Wei

2017-12-01

The effects of periodic rewatering after drought stress and nitrogen fertilizer on growth, yield, photosynthetic characteristics of leaves and water and nitrogen productivity of Coffea arabica (Katim P7963) were studied under different nitrogen application levels in 2.5 consecutive years. Irrigation (periodic rewatering after drought stress) and nitrogen were designed as two factors, with four modes of irrigation, namely, full irrigation (I F-F : 100%ET 0 +100%ET 0 , ET 0 was reference crop evapotranspiration), rewatering after light drought stress (I L-F : 80%ET 0 +100%ET 0 ), rewatering after moderate drought stress (I M-F : 60%ET 0 +100%ET 0 ) and rewatering after severe drought stress (I S-F : 40%ET 0 +100%ET 0 ), and three levels of nitrogen, namely, high nitrogen (N H : 750 kg N·hm -2 each time), middle nitrogen (N M : 500 kg N·hm -2 each time), low nitrogen (N L : 250 kg N·hm -2 each time), and nitrogen was equally applied for 4 times. The results showed that irrigation and nitrogen had significant effect on plant height, stem diameter, yield and water and nitrogen productivity of C. arabica, and plant height and stem diameter showed S-curve with the day ordinal number, and leaf photosynthesis decreased significantly under drought stress but most photosynthesis index recovered somewhat after rewatering. Compared with I F-F , I L-F increased dry bean yield by 6.9%, while I M-F and I S-F decreased dry bean yield by 15.2% and 38.5%, respectively; I L-F and I M-F increased water use efficiency by 18.8% and 6.0%, respectively, while I S-F decreased water use efficiency by 12.1%; I L-F increased nitrogen partial productivity by 6.1%, while I M-F and I S-F decreased nitrogen partial productivity by 14.0% and 36.0%, respectively. Compared with N H , N M increased dry bean yield and water use efficiency by 20.9% and 19.3%, while N L decreased dry bean yield and water use efficiency by 42.4% and 41.9%, respectively; N M and N L increased nitrogen partial

Nitrogen side-dress as a strategy to reduce defoliation demages at different growth stages of maize

OpenAIRE

Luis Sangoi; Gilmar José Picoli Junior; Vitor Paulo Vargas; Jefferson Vieira; Amauri Schmitt; Sérgio Roberto Zoldan; Eduardo Siega; Giovani Carniel

2014-01-01

Nitrogen can mitigate damages caused by leaf area reduction due to its influence on cell division. This work was carried out aiming to evaluate the efficiency of side-dressing different rates of nitrogen as a management strategy to maize stem defoliation at different growth stages. The experiment was set in Lages, during the 2008/2009 and 2009/2010 growing seasons. The experimental design was a randomized block with split plots. Three defoliation times were tested in the main plot: eight expa...

Klebsiella pneumoniae inoculants for enhancing plant growth

Science.gov (United States)

Triplett, Eric W [Middleton, WI; Kaeppler, Shawn M [Oregon, WI; Chelius, Marisa K [Greeley, CO

2008-07-01

A biological inoculant for enhancing the growth of plants is disclosed. The inoculant includes the bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101, Pantoea agglomerans P102, Klebsiella pneumoniae 342, Klebsiella pneumoniae zmvsy, Herbaspirillum seropedicae Z152, Gluconacetobacter diazotrophicus PA15, with or without a carrier. The inoculant also includes strains of the bacterium Pantoea agglomerans and K. pneumoniae which are able to enhance the growth of cereal grasses. Also disclosed are the novel bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101 and P102, and Klebsiella pneumoniae 342 and zmvsy.

Gaseous byproducts from high-temperature thermal conversion elemental analysis of nitrogen- and sulfur-bearing compounds with considerations for δ2H and δ18O analyses.

Science.gov (United States)

Hunsinger, Glendon B; Tipple, Christopher A; Stern, Libby A

2013-07-30

High-temperature, conversion-reduction (HTC) systems convert hydrogen and oxygen in materials into H2 and CO for δ(2)H and δ(18)O measurements by isotope ratio mass spectrometry. HTC of nitrogen- and sulfur-bearing materials produces unintended byproduct gases that could affect isotope analyses by: (1) allowing isotope exchange reactions downstream of the HTC reactor, (2) creating isobaric or co-elution interferences, and (3) causing deterioration of the chromatography. This study characterizes these HTC byproducts. A HTC system (ThermoFinnigan TC/EA) was directly connected to a gas chromatograph/quadrupole mass spectrometer in scan mode (m/z 8 to 88) to identify the volatile products generated by HTC at conversion temperatures of 1350 °C and 1450 °C for a range of nitrogen- and sulfur-bearing solids [keratin powder, horse hair, caffeine, ammonium nitrate, potassium nitrate, ammonium sulfate, urea, and three nitrated organic explosives (PETN, RDX, and TNT)]. The prominent HTC byproduct gases include carbon dioxide, hydrogen cyanide, methane, acetylene, and water for all nitrogen-bearing compounds, as well as carbon disulfide, carbonyl sulfide, and hydrogen sulfide for sulfur-bearing compounds. The 1450 °C reactor temperature reduced the abundance of most byproduct gases, but increased the significant byproduct, hydrogen cyanide. Inclusion of a post-reactor chemical trap containing Ascarite II and Sicapent, in series, eliminated the majority of byproducts. This study identified numerous gaseous HTC byproducts. The potential adverse effects of these gases on isotope ratio analyses are unknown but may be mitigated by higher HTC reactor temperatures and purifying the products with a purge-and-trap system or with chemical traps. Published in 2013. This article is a U.S. Government work and is in the public domain in the USA.

The effect of Nitrogen on Radiation Use Efficiency and Growth indices of Maize Hybrids (Zea mays L. under Kermanshah Condition

Directory of Open Access Journals (Sweden)

M Ahmadi

2018-02-01

Full Text Available Introduction Dry matter produced by crops is a function of absorbed radiation and radiation use efficiency. Radiation use efficiency is an effective approach to quantify total dry matter accumulation. It is defined as biomass produced by plant for solar radiation absorbed during growing season. Radiation use efficiency is often calculated from the linear regression slope between total dry matter accumulation and cumulative solar radiation absorbed. It is affected by species, weather conditions, crop management, plant development stages, and the production of photosynthesis compounds. Among the factors of agronomic management, nitrogen fertilizer and crop species are the most important aspects that affect the radiation use efficiency. Therefore, by considering the fact that Kermanshah province has favorable condition in terms of more natural resources such as solar radiation, the aims of the present study were evaluation of nitrogen effect on radiation use efficiency, growth indices and yield of some current maize hybrids. Materials and Methods A split plot experiment was done based on randomized complete block design with 4 replications at 2014. Treatments were 4 levels of nitrogen fertilizer application (40%, 70%, 100% and 140% of the maize demand to nitrogen which based on the amount recommended by soil experiment equivalent to 138, 238, 350 and 483 kg.ha-1 of urea as main plots and 3 maize hybrids KSC-704, BC-678 and Simon as sub plots. Leaf area index and total dry matter yield measured during growing season. Crop growth rate and relative growth ratio calculated by differentiation from fitted equation on total dry matter yield data. In order to calculate radiation use efficiency, sunny hours for Kermanshah latitude obtained from the nearest weather station. Daily solar radiation simulated by the method cited by Goudriaan and Van Laar (1993 for growing season. The absorbed radiation in each stage obtained through the multiplication simulated

Freshwater mineral nitrogen and essential elements in autotrophs in James Ross Island, West Antarctica

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Coufalík Pavel

2016-12-01

Full Text Available The lakes and watercourses are habitats for various communities of cyanobacteria and algae, which are among the few primary producers in Antarctica. The amount of nutrients in the mineral-poor Antarctic environment is a limiting factor for the growth of freshwater autotrophs in most cases. In this study, the main aim was to assess the availability of mineral nitrogen for microorganisms in cyanobacterial mats in James Ross Island. The nitrate and ammonium ions in water environment were determined as well as the contents of major elements (C, N, P, S, Na, K, Ca, Mg, Al, Fe, Mn in cyanobacterial mats. The molar ratios of C:N, C:P and N:P in mats were in focus. The growth of freshwater autotrophs seems not to be limited by the level of nitrogen, according to the content of available mineral nitrogen in water and the biogeochemical stoichiometry of C:N:P. The source of nutrients in the Ulu Peninsula is not obvious. The nitrogen fixation could enhance the nitrogen content in mats, which was observed in some samples containing the Nostoc sp.

[Effects of the nitrogen nutrition conditions on the growth and protein synthesis of carboxydobacteria].

Science.gov (United States)

Volova-Kesler, T G; Barashkov, V A; Trubachev, I N; Stasishina, G N

1979-01-01

The rate of growth of bacterial strains oxidizing carbon monoxide (Pseudomonas gazotropha Z-1156, Comamonas compransoris Z-1155, and Seliberia carboxydohydrogena Z--1062) was studied as a function of the concentration of NH4Cl in the medium. The bacteria could grow on media containing various nitrogen sources (NH4Cl, KNO3, CO(NH2)2). Changes in the amino acid content and biochemical composition of the biomass were studied during growth of the bacteria on these media. The biological value of proteins of the bacteria was estimated.

Does low stomatal conductance or photosynthetic capacity enhance growth at elevated CO2 in Arabidopsis?

Science.gov (United States)

Easlon, Hsien Ming; Carlisle, Eli; McKay, John K; Bloom, Arnold J

2015-03-01

The objective of this study was to determine if low stomatal conductance (g) increases growth, nitrate (NO3 (-)) assimilation, and nitrogen (N) utilization at elevated CO2 concentration. Four Arabidopsis (Arabidopsis thaliana) near isogenic lines (NILs) differing in g were grown at ambient and elevated CO2 concentration under low and high NO3 (-) supply as the sole source of N. Although g varied by 32% among NILs at elevated CO2, leaf intercellular CO2 concentration varied by only 4% and genotype had no effect on shoot NO3 (-) concentration in any treatment. Low-g NILs showed the greatest CO2 growth increase under N limitation but had the lowest CO2 growth enhancement under N-sufficient conditions. NILs with the highest and lowest g had similar rates of shoot NO3 (-) assimilation following N deprivation at elevated CO2 concentration. After 5 d of N deprivation, the lowest g NIL had 27% lower maximum carboxylation rate and 23% lower photosynthetic electron transport compared with the highest g NIL. These results suggest that increased growth of low-g NILs under N limitation most likely resulted from more conservative N investment in photosynthetic biochemistry rather than from low g. © 2015 American Society of Plant Biologists. All Rights Reserved.

Solubility of Hydrogen and Nitrogen in liquid cast iron during melting and mold filling

OpenAIRE

Diószegi, Attila; Elfsberg, Jessica; Diószegi, Zoltán

2016-01-01

Defect formation like gas- and shrinkage porosity at cast iron component production is related to the content of gaseous elements in the liquid metal. The present work investigate the solubility of hydrogen and nitrogen in liquid iron aimed for production of lamellar and compacted graphite cast iron. The used methods and instruments are a combination of commercial measuring devices and novel experimental assemblies for measuring solubility of hydrogen and nitrogen during melting and mold fill...

Gaseous waste processing facility

International Nuclear Information System (INIS)

Konno, Masanobu; Uchiyama, Yoshio; Suzuki, Kunihiko; Kimura, Masahiro; Kawabe, Ken-ichi.

1992-01-01

Gaseous waste recombiners 'A' and 'B' are connected in series and three-way valves are disposed at the upstream and the downstream of the recombiners A and B, and bypass lines are disposed to the recombiners A and B, respectively. An opening/closing controller for the three-way valves is interlocked with a hydrogen densitometer disposed to a hydrogen injection line. Hydrogen gas and oxygen gas generated by radiolysis in the reactor are extracted from a main condenser and caused to flow into a gaseous waste processing system. Gaseous wastes are introduced together with overheated steams to the recombiner A upon injection of hydrogen. Both of the bypass lines of the recombiners A and B are closed, and recombining reaction for the increased hydrogen gas is processed by the recombiners A and B connected in series. In an operation mode not conducting hydrogen injection, it is passed through the bypass line of the recombiner A and processed by the recombiner B. With such procedures, the increase of gaseous wastes due to hydrogen injection can be coped with existent facilities. (I.N.)

Responses of Surface Ozone Air Quality to Anthropogenic Nitrogen Deposition

Science.gov (United States)

Zhang, L.; Zhao, Y.; Tai, A. P. K.; Chen, Y.; Pan, Y.

2017-12-01

Human activities have substantially increased atmospheric deposition of reactive nitrogen to the Earth's surface, inducing unintentional effects on ecosystems with complex environmental and climate consequences. One consequence remaining unexplored is how surface air quality might respond to the enhanced nitrogen deposition through surface-atmosphere exchange. We combine a chemical transport model (GEOS-Chem) and a global land model (Community Land Model) to address this issue with a focus on ozone pollution in the Northern Hemisphere. We consider three processes that are important for surface ozone and can be perturbed by addition of atmospheric deposited nitrogen: emissions of biogenic volatile organic compounds (VOCs), ozone dry deposition, and soil nitrogen oxide (NOx) emissions. We find that present-day anthropogenic nitrogen deposition (65 Tg N a-1 to the land), through enhancing plant growth (represented as increases in vegetation leaf area index (LAI) in the model), could increase surface ozone from increased biogenic VOC emissions, but could also decrease ozone due to higher ozone dry deposition velocities. Meanwhile, deposited anthropogenic nitrogen to soil enhances soil NOx emissions. The overall effect on summer mean surface ozone concentrations show general increases over the globe (up to 1.5-2.3 ppbv over the western US and South Asia), except for some regions with high anthropogenic NOx emissions (0.5-1.0 ppbv decreases over the eastern US, Western Europe, and North China). We compare the surface ozone changes with those driven by the past 20-year climate and historical land use changes. We find that the impacts from anthropogenic nitrogen deposition can be comparable to the climate and land use driven surface ozone changes at regional scales, and partly offset the surface ozone reductions due to land use changes reported in previous studies. Our study emphasizes the complexity of biosphere-atmosphere interactions, which can have important

Nitrogenous compounds stimulate glucose-derived acid production by oral Streptococcus and Actinomyces.

Science.gov (United States)

Norimatsu, Yuka; Kawashima, Junko; Takano-Yamamoto, Teruko; Takahashi, Nobuhiro

2015-09-01

Both Streptococcus and Actinomyces can produce acids from dietary sugars and are frequently found in caries lesions. In the oral cavity, nitrogenous compounds, such as peptides and amino acids, are provided continuously by saliva and crevicular gingival fluid. Given that these bacteria can also utilize nitrogen compounds for their growth, it was hypothesized that nitrogenous compounds may influence their acid production; however, no previous studies have examined this topic. Therefore, the present study aimed to assess the effects of nitrogenous compounds (tryptone and glutamate) on glucose-derived acid production by Streptococcus and Actinomyces. Acid production was evaluated using a pH-stat method under anaerobic conditions, whereas the amounts of metabolic end-products were quantified using high performance liquid chromatography. Tryptone enhanced glucose-derived acid production by up to 2.68-fold, whereas glutamate enhanced Streptococcus species only. However, neither tryptone nor glutamate altered the end-product profiles, indicating that the nitrogenous compounds stimulate the whole metabolic pathways involving in acid production from glucose, but are not actively metabolized, nor do they alter metabolic pathways. These results suggest that nitrogenous compounds in the oral cavity promote acid production by Streptococcus and Actinomyces in vivo. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

AMT1;1 transgenic rice plants with enhanced NH4(+) permeability show superior growth and higher yield under optimal and suboptimal NH4(+) conditions.

Science.gov (United States)

Ranathunge, Kosala; El-Kereamy, Ashraf; Gidda, Satinder; Bi, Yong-Mei; Rothstein, Steven J

2014-03-01

The major source of nitrogen for rice (Oryza sativa L.) is ammonium (NH4(+)). The NH4(+) uptake of roots is mainly governed by membrane transporters, with OsAMT1;1 being a prominent member of the OsAMT1 gene family that is known to be involved in NH4(+) transport in rice plants. However, little is known about its involvement in NH4(+) uptake in rice roots and subsequent effects on NH4(+) assimilation. This study shows that OsAMT1;1 is a constitutively expressed, nitrogen-responsive gene, and its protein product is localized in the plasma membrane. Its expression level is under the control of circadian rhythm. Transgenic rice lines (L-2 and L-3) overexpressing the OsAMT1;1 gene had the same root structure as the wild type (WT). However, they had 2-fold greater NH4(+) permeability than the WT, whereas OsAMT1;1 gene expression was 20-fold higher than in the WT. Analogous to the expression, transgenic lines had a higher NH4(+) content in the shoots and roots than the WT. Direct NH4(+) fluxes in the xylem showed that the transgenic lines had significantly greater uptake rates than the WT. Higher NH4(+) contents also promoted higher expression levels of genes in the nitrogen assimilation pathway, resulting in greater nitrogen assimilates, chlorophyll, starch, sugars, and grain yield in transgenic lines than in the WT under suboptimal and optimal nitrogen conditions. OsAMT1;1 also enhanced overall plant growth, especially under suboptimal NH4(+) levels. These results suggest that OsAMT1;1 has the potential for improving nitrogen use efficiency, plant growth, and grain yield under both suboptimal and optimal nitrogen fertilizer conditions.

AMT1;1 transgenic rice plants with enhanced NH4 + permeability show superior growth and higher yield under optimal and suboptimal NH4 + conditions

Science.gov (United States)

Rothstein, Steven J.

2014-01-01

The major source of nitrogen for rice (Oryza sativa L.) is ammonium (NH4 +). The NH4 + uptake of roots is mainly governed by membrane transporters, with OsAMT1;1 being a prominent member of the OsAMT1 gene family that is known to be involved in NH4 + transport in rice plants. However, little is known about its involvement in NH4 + uptake in rice roots and subsequent effects on NH4 + assimilation. This study shows that OsAMT1;1 is a constitutively expressed, nitrogen-responsive gene, and its protein product is localized in the plasma membrane. Its expression level is under the control of circadian rhythm. Transgenic rice lines (L-2 and L-3) overexpressing the OsAMT1;1 gene had the same root structure as the wild type (WT). However, they had 2-fold greater NH4 + permeability than the WT, whereas OsAMT1;1 gene expression was 20-fold higher than in the WT. Analogous to the expression, transgenic lines had a higher NH4 + content in the shoots and roots than the WT. Direct NH4 + fluxes in the xylem showed that the transgenic lines had significantly greater uptake rates than the WT. Higher NH4 + contents also promoted higher expression levels of genes in the nitrogen assimilation pathway, resulting in greater nitrogen assimilates, chlorophyll, starch, sugars, and grain yield in transgenic lines than in the WT under suboptimal and optimal nitrogen conditions. OsAMT1;1 also enhanced overall plant growth, especially under suboptimal NH4 + levels. These results suggest that OsAMT1;1 has the potential for improving nitrogen use efficiency, plant growth, and grain yield under both suboptimal and optimal nitrogen fertilizer conditions. PMID:24420570

Enhanced detection of nitrogen dioxide via combined heating and pulsed UV operation of indium oxide nano-octahedra

Directory of Open Access Journals (Sweden)

Oriol Gonzalez

2016-10-01

Full Text Available We report on the use of combined heating and pulsed UV light activation of indium oxide gas sensors for enhancing their performance in the detection of nitrogen dioxide in air. Indium oxide nano-octahedra were synthesized at high temperature (900 °C via vapour-phase transport and screen-printed onto alumina transducers that comprised interdigitated electrodes and a heating resistor. Compared to the standard, constant temperature operation of the sensor, mild heating (e.g., 100 °C together with pulsed UV light irradiation employing a commercially available, 325 nm UV diode (square, 1 min period, 15 mA drive current signal, results in an up to 80-fold enhancement in sensitivity to nitrogen dioxide. Furthermore, this combined operation method allows for making savings in power consumption that range from 35% to over 80%. These results are achieved by exploiting the dynamics of sensor response under pulsed UV light, which convey important information for the quantitative analysis of nitrogen dioxide.

Enhanced detection of nitrogen dioxide via combined heating and pulsed UV operation of indium oxide nano-octahedra.

Science.gov (United States)

Gonzalez, Oriol; Roso, Sergio; Vilanova, Xavier; Llobet, Eduard

2016-01-01

We report on the use of combined heating and pulsed UV light activation of indium oxide gas sensors for enhancing their performance in the detection of nitrogen dioxide in air. Indium oxide nano-octahedra were synthesized at high temperature (900 °C) via vapour-phase transport and screen-printed onto alumina transducers that comprised interdigitated electrodes and a heating resistor. Compared to the standard, constant temperature operation of the sensor, mild heating (e.g., 100 °C) together with pulsed UV light irradiation employing a commercially available, 325 nm UV diode (square, 1 min period, 15 mA drive current signal), results in an up to 80-fold enhancement in sensitivity to nitrogen dioxide. Furthermore, this combined operation method allows for making savings in power consumption that range from 35% to over 80%. These results are achieved by exploiting the dynamics of sensor response under pulsed UV light, which convey important information for the quantitative analysis of nitrogen dioxide.

Gaseous emissions in pressurised fluidised-bed combustion. Analysis and summary of the pilot experiments

International Nuclear Information System (INIS)

Korpela, T.; Hippinen, I.; Konkola, M.

1996-01-01

The influence of operating conditions on gaseous emissions in pressurised fluidised-bed combustion have been studied. The research objectives have been behaviour of sulphur absorbents and reduction of sulphur dioxide emissions, reduction of nitrogen oxide emissions, release of vapour-phase alkalimetals and carbon monoxide emissions. The sulphur capture capacities of calcium-based sorbents under PFBC conditions have been studied at a pressurised fluidised-bed reactor and at a pressurised thermogravimetric apparatus. The project has also connected results of the experimental PFBC at HUT/EVO. (author)

Enhancement of electron field emission of vertically aligned carbon nanotubes by nitrogen plasma treatment

Energy Technology Data Exchange (ETDEWEB)

Wang, B.B. [College of Chemistry and Chemical Engineering, Chongqing University of Technology, 69 Hongguang Rd, Lijiatuo, Banan District, Chongqing 400054 (China); Plasma Nanoscience Centre Australia (PNCA), CSIRO Materials Science and Engineering, P.O. Box 218, Lindfield, NSW 2070 (Australia); Cheng, Q.J. [Plasma Nanoscience Centre Australia (PNCA), CSIRO Materials Science and Engineering, P.O. Box 218, Lindfield, NSW 2070 (Australia); Plasma Nanoscience, School of Physics, University of Sydney, Sydney, NSW 2006 (Australia); Chen, X. [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); Ostrikov, K., E-mail: kostya.ostrikov@csiro.au [Plasma Nanoscience Centre Australia (PNCA), CSIRO Materials Science and Engineering, P.O. Box 218, Lindfield, NSW 2070 (Australia); Plasma Nanoscience, School of Physics, University of Sydney, Sydney, NSW 2006 (Australia)

2011-09-22

Highlights: > A new and custom-designed bias-enhanced hot-filament chemical vapor deposition system is developed to synthesize vertically aligned carbon nanotubes. > The carbon nanotubes are later treated with nitrogen plasmas. > The electron field emission characteristics of the carbon nanotubes are significantly improved after the nitrogen plasma treatment. > A new physical mechanism is proposed to interpret the improvement of the field emission characteristics. - Abstract: The electron field emission (EFE) characteristics from vertically aligned carbon nanotubes (VACNTs) without and with treatment by the nitrogen plasma are investigated. The VACNTs with the plasma treatment showed a significant improvement in the EFE property compared to the untreated VACNTs. The morphological, structural, and compositional properties of the VACNTs are extensively examined by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and energy dispersive X-ray spectroscopy. It is shown that the significant EFE improvement of the VACNTs after the nitrogen plasma treatment is closely related to the variation of the morphological and structural properties of the VACNTs. The high current density (299.6 {mu}A/cm{sup 2}) achieved at a low applied field (3.50 V/{mu}m) suggests that the VACNTs after nitrogen plasma treatment can serve as effective electron field emission sources for numerous applications.

Enhancement of electron field emission of vertically aligned carbon nanotubes by nitrogen plasma treatment

International Nuclear Information System (INIS)

Wang, B.B.; Cheng, Q.J.; Chen, X.; Ostrikov, K.

2011-01-01

Highlights: → A new and custom-designed bias-enhanced hot-filament chemical vapor deposition system is developed to synthesize vertically aligned carbon nanotubes. → The carbon nanotubes are later treated with nitrogen plasmas. → The electron field emission characteristics of the carbon nanotubes are significantly improved after the nitrogen plasma treatment. → A new physical mechanism is proposed to interpret the improvement of the field emission characteristics. - Abstract: The electron field emission (EFE) characteristics from vertically aligned carbon nanotubes (VACNTs) without and with treatment by the nitrogen plasma are investigated. The VACNTs with the plasma treatment showed a significant improvement in the EFE property compared to the untreated VACNTs. The morphological, structural, and compositional properties of the VACNTs are extensively examined by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and energy dispersive X-ray spectroscopy. It is shown that the significant EFE improvement of the VACNTs after the nitrogen plasma treatment is closely related to the variation of the morphological and structural properties of the VACNTs. The high current density (299.6 μA/cm 2 ) achieved at a low applied field (3.50 V/μm) suggests that the VACNTs after nitrogen plasma treatment can serve as effective electron field emission sources for numerous applications.

Enhanced photoluminescence from single nitrogen-vacancy defects in nanodiamonds coated with phenol-ionic complexes

Science.gov (United States)

Bray, Kerem; Previdi, Rodolfo; Gibson, Brant C.; Shimoni, Olga; Aharonovich, Igor

2015-03-01

Fluorescent nanodiamonds are attracting major attention in the field of bio-sensing and bio-labeling. In this work we demonstrate a robust approach to achieve an encapsulation of individual nanodiamonds with phenol-ionic complexes that enhance the photoluminescence from single nitrogen vacancy (NV) centers. We show that single NV centres in the coated nanodiamonds also exhibit shorter lifetimes, opening another channel for high resolution sensing. We propose that the nanodiamond encapsulation reduces the non-radiative decay pathways of the NV color centers. Our results provide a versatile and assessable way to enhance photoluminescence from nanodiamond defects that can be used in a variety of sensing and imaging applications.Fluorescent nanodiamonds are attracting major attention in the field of bio-sensing and bio-labeling. In this work we demonstrate a robust approach to achieve an encapsulation of individual nanodiamonds with phenol-ionic complexes that enhance the photoluminescence from single nitrogen vacancy (NV) centers. We show that single NV centres in the coated nanodiamonds also exhibit shorter lifetimes, opening another channel for high resolution sensing. We propose that the nanodiamond encapsulation reduces the non-radiative decay pathways of the NV color centers. Our results provide a versatile and assessable way to enhance photoluminescence from nanodiamond defects that can be used in a variety of sensing and imaging applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07510b

Effect of two doses of urea foliar application on leaves and grape nitrogen composition during two vintages.

Science.gov (United States)

Pérez-Álvarez, Eva P; Garde-Cerdán, Teresa; García-Escudero, Enrique; Martínez-Vidaurre, José María

2017-06-01

Nitrogen affects grapevine growth and also yeast metabolism, which have a direct influence on fermentation kinetics and the formation of different volatile compounds. Throughout the grapevine cycle, soil nitrogen availability and grape nitrogen composition can vary because of different factors. Nitrogen foliar applications can contribute toward enhancing grapevine nitrogen status and minimize the problem of leaching that traditional nitrogen-soil applications can provoke. The present study aimed to evaluate the influence of urea foliar applications on grapevine nitrogen status and grape amino acid content. Accordingly, two different doses of urea were applied over the leaves of a 'Tempranillo' vineyard. The highest urea doses affected nitrogen content on blade leaf tissues after veraison. Must amino acid profiles were modified by urea application and some of the compounds increased their concentrations. The effect of year on the increase of must total amino acid concentrations was more important than the effect of the doses applied. Urea foliar applications can be an interesting tool for decreasing grapevine nitrogen deficiencies. This method of nitrogen implementation in the vineyard could avoid sluggish fermentation problems during winemaking, enhance must nitrogen composition, and contribute to improving wine quality. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Influence of the technique for injection of flue gas and the configuration of the swirl burner throat on combustion of gaseous fuel and formation of nitrogen oxides in the flame

Science.gov (United States)

Dvoinishnikov, V. A.; Khokhlov, D. A.; Knyaz'kov, V. P.; Ershov, A. Yu.

2017-05-01

How the points at which the flue gas was injected into the swirl burner and the design of the burner outlet influence the formation and development of the flame in the submerged space, as well as the formation of nitrogen oxides in the combustion products, have been studied. The object under numerical investigation is the flame of the GMVI combined (oil/gas) burner swirl burner fitted with a convergent, biconical, cylindrical, or divergent throat at the burner outlet with individual supply of the air and injection of the gaseous fuel through tubing. The burners of two designs were investigated; they differ by the absence or presence of an inlet for individual injection of the flue gas. A technique for numerical simulation of the flame based on the CFD methods widely used in research of this kind underlies the study. Based on the summarized results of the numerical simulation of the processes that occur in jet flows, the specific features of the aerodynamic pattern of the flame have been established. It is shown that the flame can be conventionally divided into several sections over its length in all investigations. The lengths of each of the sections, as well as the form of the fields of axial velocity, temperatures, concentrations of the fuel, oxygen, and carbon and nitrogen oxides, are different and determined by the design features of the burner, the flow rates of the agent, and the compositions of the latter in the burner ducts as well as the configuration of the burner throat and the temperature of the environment. To what degree the burner throat configuration and the techniques for injection of the flue gas at different ambient temperatures influence the formation of nitrogen oxides has been established. It is shown that the supply of the recirculation of flue gas into the fuel injection zone enables a considerable reduction in the formation of nitrogen oxides in the flame combustion products. It has been established that the locations of the zones of

Amelioration of bauxite residue sand by intermittent additions of nitrogen fertiliser and leaching fractions: The effect on growth of kikuyu grass and fate of applied nutrients.

Science.gov (United States)

Kaur, Navjot; Phillips, Ian; Fey, Martin V

2016-04-15

Bauxite residue, a waste product of aluminium processing operations is characterised by high pH, salinity and exchangeable sodium which hinders sustainable plant growth. The aim of this study was to investigate the uptake form, optimum application rate and timing of nitrogen fertiliser to improve bauxite residue characteristics for plant growth. Kikuyu grass was grown in plastic columns filled with residue sand/carbonated residue mud mixture (20:1) previously amended with gypsum, phosphoric acid and basal nutrients. The experiment was set up as a 4×4 factorial design comprising four levels of applied nitrogen (N) fertiliser (0, 3, 6 and 12mgNkg(-1) residue) and four frequencies of leaching (16, 8 and 4day intervals). We hypothesised that the use of ammonium sulfate fertiliser would increase retention of N within the rhizosphere thereby encouraging more efficient fertiliser use. We found that N uptake by kikuyu grass was enhanced due to leaching of excess salts and alkalinity from the residue profile. It was also concluded that biomass production and associated N uptake by kikuyu grass grown in residue is dependent on the type of fertiliser used. Copyright © 2016 Elsevier B.V. All rights reserved.

Correlation of Helium Solubility in Liquid Nitrogen

Science.gov (United States)

VanDresar, Neil T.; Zimmerli, Gregory A.

2012-01-01

A correlation has been developed for the equilibrium mole fraction of soluble gaseous helium in liquid nitrogen as a function of temperature and pressure. Experimental solubility data was compiled and provided by National Institute of Standards and Technology (NIST). Data from six sources was used to develop a correlation within the range of 0.5 to 9.9 MPa and 72.0 to 119.6 K. The relative standard deviation of the correlation is 6.9 percent.

Low-temperature conversion of ammonia to nitrogen in water with ozone over composite metal oxide catalyst.

Science.gov (United States)

Chen, Yunnen; Wu, Ye; Liu, Chen; Guo, Lin; Nie, Jinxia; Chen, Yu; Qiu, Tingsheng

2018-04-01

As one of the most important water pollutants, ammonia nitrogen emissions have increased year by year, which has attracted people's attention. Catalytic ozonation technology, which involves production of ·OH radical with strong oxidation ability, is widely used in the treatment of organic-containing wastewater. In this work, MgO-Co 3 O 4 composite metal oxide catalysts prepared with different fabrication conditions have been systematically evaluated and compared in the catalytic ozonation of ammonia (50mg/L) in water. In terms of high catalytic activity in ammonia decomposition and high selectivity for gaseous nitrogen, the catalyst with MgO-Co 3 O 4 molar ratio 8:2, calcined at 500°C for 3hr, was the best one among the catalysts we tested, with an ammonia nitrogen removal rate of 85.2% and gaseous nitrogen selectivity of 44.8%. In addition, the reaction mechanism of ozonation oxidative decomposition of ammonia nitrogen in water with the metal oxide catalysts was discussed. Moreover, the effect of coexisting anions on the degradation of ammonia was studied, finding that SO 4 2- and HCO 3 - could inhibit the catalytic activity while CO 3 2- and Br - could promote it. The presence of coexisting cations had very little effect on the catalytic ozonation of ammonia nitrogen. After five successive reuses, the catalyst remained stable in the catalytic ozonation of ammonia. Copyright © 2017. Published by Elsevier B.V.

Growth versus metabolic tissue replacement in mouse tissues determined by stable carbon and nitrogen isotope analysis

Science.gov (United States)

Macavoy, S. E.; Jamil, T.; Macko, S. A.; Arneson, L. S.

2003-12-01

Stable isotope analysis is becoming an extensively used tool in animal ecology. The isotopes most commonly used for analysis in terrestrial systems are those of carbon and nitrogen, due to differential carbon fractionation in C3 and C4 plants, and the approximately 3‰ enrichment in 15N per trophic level. Although isotope signatures in animal tissues presumably reflect the local food web, analysis is often complicated by differential nutrient routing and fractionation by tissues, and by the possibility that large organisms are not in isotopic equilibrium with the foods available in their immediate environment. Additionally, the rate at which organisms incorporate the isotope signature of a food through both growth and metabolic tissue replacement is largely unknown. In this study we have assessed the rate of carbon and nitrogen isotopic turnover in liver, muscle and blood in mice following a diet change. By determining growth rates, we were able to determine the proportion of tissue turnover caused by growth versus that caused by metabolic tissue replacement. Growth was found to account for approximately 10% of observed tissue turnover in sexually mature mice (Mus musculus). Blood carbon was found to have the shortest half-life (16.9 days), followed by muscle (24.7 days). Liver carbon turnover was not as well described by the exponential decay equations as other tissues. However, substantial liver carbon turnover was observed by the 28th day after diet switch. Surprisingly, these tissues primarily reflect the carbon signature of the protein, rather than carbohydrate, source in their diet. The nitrogen signature in all tissues was enriched by 3 - 5‰ over their dietary protein source, depending on tissue type, and the isotopic turnover rates were comparable to those observed in carbon.

Rapid hydrogen hydrate growth from non-stoichiometric tuning mixtures during liquid nitrogen quenching.

Science.gov (United States)

Grim, R Gary; Kerkar, Prasad B; Sloan, E Dendy; Koh, Carolyn A; Sum, Amadeu K

2012-06-21

In this study the rapid growth of sII H(2) hydrate within 20 min of post formation quenching towards liquid nitrogen (LN(2)) temperature is presented. Initially at 72 MPa and 258 K, hydrate samples would cool to the conditions of ~60 MPa and ~90 K after quenching. Although within the stability region for H(2) hydrate, new hydrate growth only occurred under LN(2) quenching of the samples when preformed hydrate "seeds" of THF + H(2) were in the presence of unconverted ice. The characterization of hydrate seeds and the post-quenched samples was performed with confocal Raman spectroscopy. These results suggest that quenching to LN(2) temperature, a common preservation technique for ex situ hydrate analysis, can lead to rapid unintended hydrate growth. Specifically, guest such as H(2) that may otherwise need sufficiently long induction periods to nucleate, may still experience rapid growth through an increased kinetic effect from a preformed hydrate template.

The importance of nitrogen and carbohydrate storage for plant growth of the alpine herb Veratrum album

NARCIS (Netherlands)

Kleijn, D.; Treier, U.A.; Müller-Schärer, H.

2005-01-01

We examined whether nitrogen (N) and carbohydrates reserves allow Veratrum album, an alpine forb, to start spring growth earlier than the neighbouring vegetation and to survive unpredictable disturbances resulting in loss of above-ground biomass. Seasonal dynamics of plant reserves, soil N

Enhancing Nitrogen Availability, Ammonium Adsorption-Desorption, and Soil pH Buffering Capacity using Composted Paddy Husk

Science.gov (United States)

Latifah, O.; Ahmed, O. H.; Abdul Majid, N. M.

2017-12-01

Form of nitrogen present in soils is one of the factors that affect nitrogen loss. Nitrate is mobile in soils because it does not absorb on soil colloids, thus, causing it to be leached by rainfall to deeper soil layers or into the ground water. On the other hand, temporary retention and timely release of ammonium in soils regulate nitrogen availability for crops. In this study, composted paddy husk was used in studies of soil leaching, buffering capacity, and ammonium adsorption and desorption to determine the: (i) availability of exchangeable ammonium, available nitrate, and total nitrogen in an acid soil after leaching the soil for 30 days, (ii) soil buffering capacity, and (iii) ability of the composted paddy husk to adsorb and desorb ammonium from urea. Leaching of ammonium and nitrate were lower in all treatments with urea and composted paddy husk compared with urea alone. Higher retention of soil exchangeable ammonium, available nitrate, and total nitrogen of the soils with composted paddy husk were due to the high buffering capacity and cation exchange capacity of the amendment to adsorb ammonium thus, improving nitrogen availability through temporary retention on the exchange sites of the humic acids of the composted paddy husk. Nitrogen availability can be enhanced if urea is amended with composted paddy husk.

The study on effect of zeolite on nitrogen use efficiency of corn by 15N-isotope dilution method

International Nuclear Information System (INIS)

Li Changhong; Li Huaxing; Zhang Xinming; Liu Yuanjin

2002-01-01

A pot experiment was carried out to study the effect of natural zeolite on nitrogen use efficiency of corn by using 15 N-isotope dilution method. The results showed that application of zeolite could improve the corn growth and enhance the biomass of the corn seedling. By using zeolite, nitrogen use efficiency (NUE) of corn was increased by 23.2%-33.1% as compared with no-zeolite treatment; and the residual nitrogen has no significant difference between zeolite treatment and no-zeolite treatment

Penggunaan Azospirillum pada Tanah Masam dengan Aluminium Tinggi Terhadap Produksi dan Serapan Nitrogen Rumput Setaria splendida dan Chloris gayana

Directory of Open Access Journals (Sweden)

P.D.M.H. Karti

2005-04-01

Full Text Available High content of Al on the soil maybe harmful (toxic for plant. Red and yellow podzolic soil was marginal land that characterized by high Al content. Azospirillum is free living N fixing bacteria that can be associated with grass. This research was conducted to find the best yield of grass planted on the soil inoculated with Azospirillum. The research consisted of some steps; 1 soil sampling 2 laboratory research: bacterial isolation, isolate selection, standardized of population, content of IAA 3 pod experiment. Pod experiment in the glass house was designed in completely randomized design, that consisted of six treatments. The variables observed were dry mass production of shoot and root, nitrogen content of shoot and root, and nitrogen absorption. Four best isolates chosen were; SM Setaria, OBIS/BD, PO2 and PM2. Azospirillum isolates enhanced shoot and root production, nitrogen content and N total absorption of tolerance one (S. splendida. The susceptible (C. gayana, Azospirillum significantly enhanced shoot and root nitrogen content, but did not affect the growth, production and N total absorption. Root growth that was inhibited by Al toxicity, decreased the symbiotic capability of nitrogen fixing bacteria. PM2 isolate showed the best effect on production and quality of S. splendida as well as on C. gayana. This isolate will be used for future research. PM2 produces 6.4 ppm Indole Acetic Acid that promoted root growth.

Absorption of continuum radiation in a resonant expanding gaseous sphere

International Nuclear Information System (INIS)

Shaparev, N Y

2014-01-01

The paper deals with absorption of external continuum radiation in a self-similarly expanding gaseous sphere. Frequency probability and integral probability of radiation absorption in the resonance frequency range are determined depending on the expansion velocity gradient and thickness of the optical medium. It is shown that expansion results in a reduced optical thickness of the medium and enhanced integral absorption. (paper)

Nitrogen gas emissions and nitrate leaching dynamics under different tillage practices based on data synthesis and process-based modeling

Science.gov (United States)

Huang, Y.; Ren, W.; Tao, B.; Zhu, X.

2017-12-01

Nitrogen losses from the agroecosystems have been of great concern to global changes due to the effects on global warming and water pollution in the form of nitrogen gas emissions (e.g., N2O) and mineral nitrogen leaching (e.g., NO3-), respectively. Conservation tillage, particularly no-tillage (NT), may enhance soil carbon sequestration, soil aggregation and moisture; therefore it has the potential of promoting N2O emissions and reducing NO3- leaching, comparing with conventional tillage (CT). However, associated processes are significantly affected by various factors, such as soil properties, climate, and crop types. How tillage management practices affect nitrogen transformations and fluxes is still far from clear, with inconsistent even opposite results from previous studies. To fill this knowledge gap, we quantitatively investigated gaseous and leaching nitrogen losses from NT and CT agroecosystems based on data synthesis and an improved process-based agroecosystem model. Our preliminary results suggest that NT management is more efficient in reducing NO3- leaching, and meanwhile it simultaneously increases N2O emissions by approximately 10% compared with CT. The effects of NT on N2O emissions and NO3- leaching are highly influenced by the placement of nitrogen fertilizer and are more pronounced in humid climate conditions. The effect of crop types is a less dominant factor in determining N2O and NO3- losses. Both our data synthesis and process-based modeling suggest that the enhanced carbon sequestration capacity from NT could be largely compromised by relevant NT-induced increases in N2O emissions. This study provides the comprehensive quantitative assessment of NT on the nitrogen emissions and leaching in agroecosystems. It provides scientific information for identifying proper management practices for ensuring food security and minimizing the adverse environmental impacts. The results also underscore the importance of suitable nitrogen management in the NT

Facile fabrication of palladium-ionic liquids-nitrogen-doped graphene nanocomposites as enhanced electro-catalyst for ethanol oxidation

Science.gov (United States)

Li, Shuwen; Yang, Honglei; Ren, Ren; Ma, Jianxin; Jin, Jun; Ma, Jiantai

2015-10-01

The palladium-ionic liquids-nitrogen-doped graphene nanocomposites are facile fabricated as enhanced electro-catalyst for ethanol oxidation. First, the ionic liquids functionalized nitrogen-doping graphene nanosheets (PDIL-NGS) with few layers is synthesized through a facile and effective one-pot hydrothermal method with graphene oxide as raw material, urea as reducing-doping agents and ionic liquids (ILs) derived from 3,4,9,10-perylene tetracarboxylic acid as functional molecules. The results of systematic characterization reveal that the PDIL molecules not only can functionalize NGS by π-π stacking with no affecting the nitrogen doping but also prevent the agglomeration of NGS. More importantly, the processing performance and the property of electron transfer are remarkably enhanced duo to introducing a large number of ILs groups. Then, the enhanced electrocatalytic Pd nanoparticles are successfully anchored on PDIL-NGS by a facile and surfactant-free synthetic technique. As an anode catalyst, the novel catalyst exhibits better kinetics, more superior electrocatalytic performance, higher tolerance and electrochemical stability than the other catalysts toward ethanol electrooxidation, owing to the role of PDIL molecules. Therefore, the new catalyst is believed to have the potential use for direct alcohol fuel cells in the future and the functionalized NGS is promising useful materials applied in other fields.

Gaseous radioactive waste processing system

International Nuclear Information System (INIS)

Onizawa, Hideo.

1976-01-01

Object: To prevent explosion of hydrogen gas within gaseous radioactive waste by removing the hydrogen gas by means of a hydrogen absorber. Structure: A coolant extracted from a reactor cooling system is sprayed by nozzle into a gaseous phase (hydrogen) portion within a tank, thus causing slipping of radioactive rare gas. The gaseous radioactive waste rich in hydrogen, which is purged in the tank, is forced by a waste gas compressor into a hydrogen occlusion device. The hydrogen occlusion device is filled with hydrogen occluding agents such as Mg, Mg-Ni alloy, V-Nb alloy, La-Ni alloy and so forth, and hydrogen in the waste gas is removed through reaction to produce hydrogen metal. The gaseous radioactive waste, which is deprived of hydrogen and reduced in volume, is stored in an attenuation tank. The hydrogen stored in the hydrogen absorber is released and used again as purge gas. (Horiuchi, T.)

Nitrogen consumption, utilisation and losses in pig production in France, The Netherlands, and Denmark

NARCIS (Netherlands)

Dourmad, J.Y.; SOve, B.; Latimer, P.; Boisen, S.; Fernández, J.; Peet-Schwering, van der C.; Jongbloed, A.W.

1999-01-01

In highly intensive pig production areas, manure disposal is a major problem especially for nitrogen, because of water pollution by nitrates and air pollution by gaseous ammonia emissions. The situations in three European countries (Denmark, The Netherlands and France) were compared, on average, it

An explanation for why it is difficult to form slush nitrogen from liquid nitrogen used previously for this purpose.

Science.gov (United States)

Baker, Michael J; Denton, Travis T; Herr, Charles

2013-02-01

Slush nitrogen (SN) is used to avoid the Leidenfrost effect, which is problematic when using liquid nitrogen (LN). Slush nitrogen's usefulness has been demonstrated by its requirement for the successful cryopreservation of insect embryos. To convert LN to SN, typically, the pressure above a Dewar of LN is reduced, using a vacuum pump in a sealed system until conversion occurs. It has been observed that LN from a fresh tank will readily produce SN; however, repeated use of the same LN results in the inability to form SN in subsequent trials. The current experiments were designed to identify the cause of this phenomenon. The hypothesis is that gaseous oxygen from the surrounding, ambient air condenses and mixes with the LN to form a mixture with a lower freezing point and; therefore, prevents the formation of SN. The hypothesis was tested and found to be true. Copyright © 2012. Published by Elsevier Inc.

Growth and yield of corn hybrids in response to association with Azospirillum brasilense and nitrogen fertilization

Directory of Open Access Journals (Sweden)

Deniele Marini

2015-02-01

Full Text Available There is a growing interest in optimizing the positive effects of the association between Azospirillum bacteria and corn crop in order to reduce the use of nitrogen fertilizers. This study aimed to evaluate the inoculation efficiency of an A. brasilense-based commercial product in association with different rates of nitrogen fertilization in two corn genotypes. The experiment was arranged in a 2 x 2 x 5 factorial randomized block design, with four replications. The treatments consisted of two corn hybrids (30F53 and CD386; with and without inoculation with a commercial product based on A. brasilense and five nitrogen rates (0, 40, 80, 120 and 160 kg ha-1. The variables plant height, basal stem diameter, leaf area, shoot dry matter, leaf nitrogen content, length and diameter of the cob, weight of 100 grains and grain yield were evaluated. Inoculation with A. brasilense provided increases of 11 and 12% in leaf area and shoot dry matter, respectively. There were differences in the response of the corn hybrids for most variables and the increase in nitrogen supply provided increments in the growth and yield of corn.

Effect of sequences of ozone and nitrogen dioxide on plant dry ...

African Journals Online (AJOL)

Ozone (O3) is the most important gaseous air pollutant in the world because of its adverse effects on vegetation in general and crop plants in particular. Since nitrogen dioxide (NO2) is a precursor of ozone, studying the implication of sequences of these two gases is very important. Hence, the effects of sequences of ...

Mass spectrometric study of thermodynamic properties of gaseous lead tellurates. Estimation of formation enthalpies of gaseous lead polonates

Energy Technology Data Exchange (ETDEWEB)

Shugurov, S.M., E-mail: s.shugurov@spbu.ru; Panin, A.I.; Lopatin, S.I.; Emelyanova, K.A.

2016-10-15

Gaseous reactions involving lead oxides, tellurium oxide and lead tellurates were studied by the Knudsen effusion mass spectrometry. Equilibrium constants and reaction enthalpies were evaluated. Structures, molecular parameters and thermodynamic functions of gaseous PbTeO{sub 3} and Pb{sub 2}TeO{sub 4} were calculated by quantum chemistry methods. The formation enthalpies Δ{sub f}H{sup 0} (298.15) = −294 ± 13 for gaseous PbTeO{sub 3} and Δ{sub f}H{sup 0} (298.15) = −499 ± 12 for gaseous Pb{sub 2}TeO{sub 4} were obtained. On the base of these results the formation enthalpies of gaseous PbPoO{sub 3} and Pb{sub 2}PoO{sub 4} were estimated as −249 ± 34 and −478 ± 38, respectively. - Highlights: • Gaseous lead tellurates PbTeO{sub 3}, Pb{sub 2}TeO{sub 4} were discovered. • Their thermodynamic properties were studied using both high temperature mass spectrometry and quantum chemistry computations. • The obtained data allows to predict the formation enthalpies of gaseous lead polonates PbPoO{sub 3}, Pb{sub 2}PoO{sub 4}.

Identification of genotypic variation for nitrogen response in potato (Solanum tuberosum) under low nitrogen input circumstances

NARCIS (Netherlands)

Tiemens-Hulscher, M.; Lammerts Van Bueren, E.; Struik, P.C.

2009-01-01

Nitrogen is an essential nutrient for crop growth. The demand for nitrogen in the potato crop is relatively high. However, in organic farming nitrogen input is rather limited, compared with conventional farming. In this research nine potato varieties were tested at three nitrogen levels. Genotypic

Does the Euro enhance Economic Growth?

DEFF Research Database (Denmark)

Dreyer, Johannes Kabderian; A. Schmid, Peter

2016-01-01

of economic integration in Europe. The aim of this article is to investigate whether the EU and EZ memberships enhance growth of their members. In order to perform our empirical analysis, we apply an augmented Solow growth model using convergence analysis and the panel Generalized Method of Moments (GMM...... interesting to new potential EZ members, such as some of the Central Eastern European Countries (CEE), who are about or in the process to join the common currency club....

[Effects of nitrogen and irrigation water application on yield, water and nitrogen utilization and soil nitrate nitrogen accumulation in summer cotton].

Science.gov (United States)

Si, Zhuan Yun; Gao, Yang; Shen, Xiao Jun; Liu, Hao; Gong, Xue Wen; Duan, Ai Wang

2017-12-01

A field experiment was carried out to study the effects of nitrogen and irrigation water application on growth, yield, and water and nitrogen use efficiency of summer cotton, and to develop the optimal water and nitrogen management model for suitable yield and less nitrogen loss in summer cotton field in the Huang-Huai region. Two experimental factors were arranged in a split plot design. The main plots were used for arranging nitrogen factor which consisted of five nitrogen fertilizer le-vels(0, 60, 120, 180, 240 kg·hm -2 , referred as N 0 , N 1 , N 2 , N 3 , N 4 ), and the subplots for irrigation factor which consisted of three irrigation quota levels (30, 22.5, 15 mm, referred as I 1 , I 2 , I 3 ). There were 15 treatments with three replications. Water was applied with drip irrigation system. Experimental results showed that both irrigation and nitrogen fertilization promoted cotton growth and yield obviously, but nitrogen fertilizer showed more important effects than irrigation and was the main factor of regulating growth and yield of summer cotton in the experimental region. With the increase of nitrogen fertilization rate and irrigation amount, the dry mater accumulation of reproductive organs, the above-ground biomass at the flowering-bolling stage and seed cotton yield increased gradually, reached peak values at nitrogen fertilization rate of 180 kg·hm -2 and decreased slowly with the nitrogen fertilization rate further increased. The maximum yield of 4016 kg·hm -2 was observed in the treatment of N 3 I 1 . Increasing nitrogen fertilizer amount would improve significantly total N absorption of shoots and N content of stem and leaf, but decrease nitrogen partial factor productivity. The maximum irrigation-water use efficiency of 5.40 kg·m -3 and field water use efficiency of 1.24 kg·m -3 were found in the treatments of N 3 I 3 and N 3 I 1 , respectively. With increasing nitrogen fertilization amount, soil NO 3 - -N content increased and the main soil

Soil emissions of gaseous reactive nitrogen from North American arid lands: an overlooked source.

Science.gov (United States)

Sparks, J. P.; McCalley, C. K.; Strahm, B. D.

2008-12-01

The biosphere-atmosphere exchange and transformation of nitrogen has important ramifications for both terrestrial biogeochemistry and atmospheric chemistry. Several important mechanisms within this process (e.g., photochemistry, nitrogen deposition, aerosol formation) are strongly influenced by the emission of reactive nitrogen compounds from the Earth's surface. Therefore, a quantification of emission sources is a high priority for future conceptual understanding. One source largely overlooked in most global treatments are the soil emissions from arid and semi-arid landscapes worldwide. Approximately 35-40% of global terrestrial land cover is aridland and emission of reactive nitrogen from soils in these regions has the potential to strongly influence both regional and global biogeochemistry. Here we present estimates of soil emission of oxidized (NO, total NOy including NO2 and HONO) and reduced (NH3) forms of reactive nitrogen from two North American arid regions: the Mojave Desert and the Colorado Plateau. Soil fluxes in these regions are highly dependent on soil moisture conditions. Soil moisture is largely driven by pulsed rain events with fluxes increasing 20-40 fold after a rain event. Using field measurements made across seasons under an array of moisture conditions, precipitation records, and spatially explicit cover type information we have estimated annual estimates for the Mojave Desert (1.5 ± 0.7 g N ha-1 yr-1), the shale derived (1.4 ± 0.9 g N ha-1 yr-1), and sandy soil derived (2.8 ± 1.2 g N ha-1 yr-1) regions of the Colorado Plateau. The chemical composition of soil emissions varies significantly both with season and soil moisture content. Emissions from dry soils tend to be dominated by ammonia and forms of NOy other than NO. In contrast, NO becomes a dominant portion of the flux post rain events (~30% of the total flux). This variability in chemical form has significant implications for the tropospheric fate of the emitted N. NO and other

7th International Symposium on Gaseous Dielectrics

CERN Document Server

James, David

1994-01-01

The Seventh International Symposium on Gaseous Dielectrics was held in Knoxville, Tennessee, U. S. A. , on April 24-28, 1994. The symposium continued the interdisciplinary character and comprehensive approach of the preceding six symposia. Gaseous DielecIries VII is a detailed record of the symposium proceedings. It covers recent advances and developments in a wide range of basic, applied and industrial areas of gaseous dielectrics. It is hoped that Gaseous DielecIries VII will aid future research and development in, and encourage wider industrial use of, gaseous dielectrics. The Organizing Committee of the Seventh International Symposium on Gaseous Dielectrics consisted of G. Addis (U. S. A. ), L. G. Christophorou (U. S. A. ), F. Y. Chu (Canada), A. H. Cookson (U. S. A. ), O. Farish (U. K. ), I. Gallimberti (Italy) , A. Garscadden (U. S. A. ), D. R. James (U. S. A. ), E. Marode (France), T. Nitta (Japan), W. Pfeiffer (Germany), Y. Qiu (China), I. Sauers (U. S. A. ), R. J. Van Brunt (U. S. A. ), and W. Zaengl...

A study of the evolution of nitrogen compounds during coal devolatilisation

Energy Technology Data Exchange (ETDEWEB)

Arenillas, A.; Rubiera, F.; Moreno, A.H.; Pevida, C.; Pis, J.J. [CSIC, Instituto Nacional del Carbon, Oviedo (Spain). Dept. of Energy and Environment

2001-07-01

Emissions of nitrogen oxides during combustion are a major environmental problem. The chemically bound nitrogen in fuel accounts for up to 80% of total NOx emissions. In this respect, fundamental studies are needed to clarify the mechanisms and to identify the different species that are precursors in the formation of the NOx. In this work, two methodologies were employed. Simultaneous thermogravimetric-mass spectrometric (TG-MS) analysis was used to study the pyrolysis behaviour of three coals of varying rank. The release of different nitrogen compounds was followed by means of temperature-programmed pyrolysis experiments. The influence of coal rank on the evolution of volatile compounds was also considered. In addition, a series of coal chars with different burn-off degrees were obtained in a bench scale fluidised bed reactor, using the same parent coal. The evolution of gaseous compounds arising from the thermal treatment of the partially burned chars was studied in the TG-MS system. It was found that the different chemical structure of the chars exerted some influence on the evolution of the gaseous compounds during the devolatilisation process. Finally, the evolution of the volatile compounds was also studied in the bench scale fluidised bed reactor. Special attention was given to the formation of N{sub 2}O during the pyrolysis of the coals used. 27 refs., 8 figs., 3 tabs.

Recent changes in anthropogenic reactive nitrogen compounds

Science.gov (United States)

Andronache, Constantin

2014-05-01

Significant anthropogenic perturbations of the nitrogen cycle are the result of rapid population growth, with mounting need for food and energy production. The increase of reactive nitrogen compounds (such as NOx, HNO3, NH3, and N2O) has a significant impact on human health, environment, and climate. NOx emissions contribute to O3 chemistry, aerosol formation and acidic precipitation. Ammonia is a notable atmospheric pollutant that may deteriorate ecosystems and contribute to respiratory problems. It reacts with acidic gases to form aerosols or is deposited back to ecosystems. The application of fertilizers accounts for most of the N2O production, adding to greenhouse gas emissions. We analyze the change of some reactive nitrogen compounds based on observations, in eastern United States. Results show that the control of NOx and SO2 emissions over the last decades caused a significant decrease of acidic deposition. The nitrate deposition is highest in eastern US, while the ammonium ion concentration is highest in central US regions. Overall, the inorganic nitrogen wet deposition from nitrate and ammonium is enhanced in central, and eastern US. Research shows that sensitive ecosystems in northeastern regions exhibit a slow recovery from the accumulated effects of acidic deposition. Given the growing demand for nitrogen in agriculture and industry, we discuss possible pathways to reduce the impact of excess reactive nitrogen on the environment.

Effect of nitrogen supply on leaf growth, leaf nitrogen economy and photosynthetic capacity in potato

NARCIS (Netherlands)

Vos, J.; Putten, van der P.E.L.

1998-01-01

Literature reports show little effect of nitrogen supply on radiation use efficiency in potato and in other dicotyledonous C3 species. This paper tests the hypothesis that potato reduces leaf size rather than leaf nitrogen concentration and photosynthetic capacity when nitrogen is in short supply.

Effectiveness of Ammonium-Nitrogen and Nitrate-Nitrogen in Irrigation Water in Paddy Rice without Topdressed Nitrogen at the Panicle Formation Stage

OpenAIRE

池田, 元輝; 渡辺, 孝賢; Ikeda, Motoki; Watanabe, Takayasu

2002-01-01

A pot experiment was conducted to evaluate the efficiency of ammonium- and nitrate- nitrogen contained in irrigation water during the reproductive growth period of paddy rice （Oryza sativa L. cv. Hinohikari） that did not receive topdressed nitrogen at the panicle formation stage. lrrigation of water containing a low level of nitrogen （7mgNL^-1） did not increase yields so much compared to topdressed nitrogen. lrrigation of water containing a high level of nitrogen （14mgNL^-1） caused substantia...

The relative importance of exogenous and substrate-derived nitrogen for microbial growth during leaf decomposition

Science.gov (United States)

B.M. Cheever; J. R. Webster; E. E. Bilger; S. A. Thomas

2013-01-01

Heterotrophic microbes colonizing detritus obtain nitrogen (N) for growth by assimilating N from their substrate or immobilizing exogenous inorganic N. Microbial use of these two pools has different implications for N cycling and organic matter decomposition in the face of the global increase in biologically available N. We used sugar maple leaves labeled with

Influence of nitrogen and phosphorous on the growth and root morphology of Acer mono.

Science.gov (United States)

Razaq, Muhammad; Zhang, Peng; Shen, Hai-Long; Salahuddin

2017-01-01

Nitrogen and phosphorous are critical determinants of plant growth and productivity, and both plant growth and root morphology are important parameters for evaluating the effects of supplied nutrients. Previous work has shown that the growth of Acer mono seedlings is retarded under nursery conditions; we applied different levels of N (0, 5, 10, and 15 g plant-1) and P (0, 4, 6 and 8 g plant-1) fertilizer to investigate the effects of fertilization on the growth and root morphology of four-year-old seedlings in the field. Our results indicated that both N and P application significantly affected plant height, root collar diameter, chlorophyll content, and root morphology. Among the nutrient levels, 10 g N and 8 g P were found to yield maximum growth, and the maximum values of plant height, root collar diameter, chlorophyll content, and root morphology were obtained when 10 g N and 8 g P were used together. Therefore, the present study demonstrates that optimum levels of N and P can be used to improve seedling health and growth during the nursery period.

The conditions of gaseous fuels development

International Nuclear Information System (INIS)

Anon.

1996-01-01

Face to the actual situation of petrol and gas oil in France, the situation of gaseous fuels appears to be rather modest. However, the aim of gaseous fuels is not to totally supersede the liquid fuels. Such a situation would imply a complete overturn which has not been seriously considered yet. This short paper describes the essential conditions to promote the wider use of gaseous fuels: the intervention of public authorities to adopt a more advantageous tax policy in agreement with the ''Clean Air''law project, a suitable distribution network for gaseous fuels, a choice of vehicles consistent with the urban demand, the development of transformation kits of quality and of dual-fuel vehicles by the car manufacturers. (J.S.)

Controlled surface diffusion in plasma-enhanced chemical vapor deposition of GaN nanowires

International Nuclear Information System (INIS)

Hou, W C; Hong, Franklin Chau-Nan

2009-01-01

This study investigates the growth of GaN nanowires by controlling the surface diffusion of Ga species on sapphire in a plasma-enhanced chemical vapor deposition (CVD) system. Under nitrogen-rich growth conditions, Ga has a tendency to adsorb on the substrate surface diffusing to nanowires to contribute to their growth. The significance of surface diffusion on the growth of nanowires is dependent on the environment of the nanowire on the substrate surface as well as the gas phase species and compositions. Under nitrogen-rich growth conditions, the growth rate is strongly dependent on the surface diffusion of gallium, but the addition of 5% hydrogen in nitrogen plasma instantly diminishes the surface diffusion effect. Gallium desorbs easily from the surface by reaction with hydrogen. On the other hand, under gallium-rich growth conditions, nanowire growth is shown to be dominated by the gas phase deposition, with negligible contribution from surface diffusion. This is the first study reporting the inhibition of surface diffusion effects by hydrogen addition, which can be useful in tailoring the growth and characteristics of nanowires. Without any evidence of direct deposition on the nanowire surface, gallium and nitrogen are shown to dissolve into the catalyst for growing the nanowires at 900 deg. C.

Position-sensitive gaseous photomultipliers research and applications

CERN Document Server

Francke, Tom; Peskov, Vladimir

2016-01-01

Gaseous photomultipliers are defined as gas-filled devices capable of recording single ultraviolet (UV) and visible photons with high position resolution. Used in a variety of research areas, these detectors can be paired with computers to treat and store imaging information of UV-light. Position-Sensitive Gaseous Photomultipliers: Research and Applications explores the advancement of gaseous detectors as applied for single photon detection. Emphasizing emerging perspectives and new ways to apply gaseous detectors across research fields, this research-based publication is an essential reference source for engineers, physicists, graduate-level students, and researchers.

Nitrogen sources affect productivity, desiccation tolerance and storage stability of Beauveria bassiana blastospores.

Science.gov (United States)

Mascarin, G M; Kobori, N N; Jackson, M A; Dunlap, C A; Delalibera, Í

2018-03-01

Nitrogen is a critical element in industrial fermentation media. This study investigated the influence of various nitrogen sources on blastospore production, desiccation tolerance and storage stability using two strains of the cosmopolitan insect-pathogenic fungus Beauveria bassiana. Complex organic sources of nitrogen such as soy flour, autolysed yeast and cottonseed flour induced great numbers of blastospores after 2-3 days of fermentation, which also survived drying and remained viable (32-56% survival) after 9 months storage at 4°C, although variations were found between strains. Nitrogen availability in the form of free amino acids directly influenced blastospore production and resistance to desiccation. Increasing glucose and nitrogen concentrations up to 120 and 30 g l -1 , respectively, did not improve blastospore production but enhanced desiccation tolerance. Cell viability after drying and upon fast-rehydration was increased when ≥25 g acid-hydrolysed casein per litre was supplemented in the liquid culture medium. These findings indicate that low-cost complex nitrogen compounds are suitable to enhance yeast-like growth by B. bassiana with good desiccation tolerance and therefore support its further scale-up production as a mycoinsecticide. Nitrogen is the most expensive nutrient in liquid media composition, but this study underscores the feasibility of using low-cost nitrogen compounds composed mainly of agro-industrial by-products for rapid production of desiccation-tolerant B. bassiana blastospores by liquid culture fermentation. © 2018 The Society for Applied Microbiology.

Thermal expansion and phase transformations of nitrogen-expanded austenite studied with in situ synchrotron X-ray diffraction

DEFF Research Database (Denmark)

Brink, Bastian; Ståhl, Kenny; Christiansen, Thomas Lundin

2014-01-01

Nitrogen-expanded austenite, _N, with high and low nitrogen contents was produced from AISI 316 grade stainless steel powder by gaseous nitriding in ammonia/hydrogen gas mixtures. In situ synchrotron X-ray diffraction was applied to investigate the thermal expansion and thermal stability...... as a fitting parameter. The stacking fault density is constant for temperatures up to 680 K, whereafter it decreases to nil. Surprisingly, a transition phase with composition M4N (M = Fe, Cr, Ni, Mo) appears for temperatures above 770 K. The linear coefficient of thermal expansion depends on the nitrogen...

A comparative investigation on the effects of nitrogen-doping into graphene on enhancing the electrochemical performance of SnO2/graphene for sodium-ion batteries.

Science.gov (United States)

Xie, Xiuqiang; Su, Dawei; Zhang, Jinqiang; Chen, Shuangqiang; Mondal, Anjon Kumar; Wang, Guoxiu

2015-02-21

SnO2/nitrogen-doped graphene nanohybrids have been synthesized by an in situ hydrothermal method, during which the formation of SnO2 nanocrystals and nitrogen doping of graphene occur simultaneously. The as-prepared SnO2/nitrogen-doped graphene nanohybrids exhibit enhanced electrochemical performance for sodium-ion batteries compared to SnO2/graphene nanocomposites. A systematic comparison between SnO2/nitrogen-doped graphene nanohybrids and the SnO2/graphene counterpart as anode materials for sodium-ion batteries has been conducted. The comparison is in a reasonable framework, where SnO2/nitrogen-doped graphene nanohybrids and the SnO2/graphene counterpart have the same SnO2 ratio, similar SnO2 crystallinity and particle size, close surface area and pore size. The results clearly manifest that the improved electron transfer efficiency of SnO2/nitrogen-doped graphene due to nitrogen-doping plays a more important role than the increased electro-active sites within graphene network in enhancing the electro-activity of SnO2/nitrogen-doped graphene nanohybrids compared to the SnO2/graphene counterpart. In contrast to the previous reports which often ascribe the enhanced electro-activity of nitrogen-doped graphene based composites to two nitrogen-doping effects (improving the electron transfer efficiency and increasing electro-active sites within graphene networks) in one single declaration, this work is expected to provide more specific information for understanding the effects of nitrogen-doping into graphene on improving the electrochemical performance of graphene based composites.

Relationship of Nitrogen Use Efficiency with the Activities of Enzymes Involved in Nitrogen Uptake and Assimilation of Finger Millet Genotypes Grown under Different Nitrogen Inputs

Directory of Open Access Journals (Sweden)

Nidhi Gupta

2012-01-01

Full Text Available Nitrogen responsiveness of three-finger millet genotypes (differing in their seed coat colour PRM-1 (brown, PRM-701 (golden, and PRM-801 (white grown under different nitrogen doses was determined by analyzing the growth, yield parameters and activities of nitrate reductase (NR, glutamine synthetase (GS, glutamate synthase; GOGAT, and glutamate dehydrogenase (GDH at different developmental stages. High nitrogen use efficiency and nitrogen utilization efficiency were observed in PRM-1 genotype, whereas high nitrogen uptake efficiency was observed in PRM-801 genotype. At grain filling nitrogen uptake efficiency in PRM-1 negatively correlated with NR, GS, GOGAT activities whereas it was positively correlated in PRM-701 and PRM-801, however, GDH showed a negative correlation. Growth and yield parameters indicated that PRM-1 responds well at high nitrogen conditions while PRM-701 and PRM-801 respond well at normal and low nitrogen conditions respectively. The study indicates that PRM-1 is high nitrogen responsive and has high nitrogen use efficiency, whereas golden PRM-701 and white PRM-801 are low nitrogen responsive genotypes and have low nitrogen use efficiency. However, the crude grain protein content was higher in PRM-801 genotype followed by PRM-701 and PRM-1, indicating negative correlation of nitrogen use efficiency with source to sink relationship in terms of seed protein content.

Cyanogenic glycosides in Lotus corniculatus : Their effect upon growth, energy budget, and nitrogen utilization of the southern armyworm, Spodoptera eridania.

Science.gov (United States)

Mark Scriber, J

1978-01-01

Two genotypes (one cyanogenic and the other acyanogenic) of birds-foot trefoil, Lotus corniculatus L., were used to study the effects of cyanogenic glycosides in leaf tissues upon a polyphagous herbivore, the southern armyworm, Spodoptera eridania Cram. (Lepidoptera). No differences were observed in consumption rate, assimilation efficiency, utilization of plant biomass, or metabolic costs in terms of expended calories between larvae fed acyanogenic or cyanogenic leaves. Similarly no differences were seen in the nitrogen or caloric utilization efficiencies, or in the nitrogen accumulation rate or growth rate of larvae on cyanogenic versus acyanogenic plants. Larval performance and growth on 20-week old plants was generally poorer than on 4 week old plants, however. This was reflected in slower growth, smaller pupal weights, lower nitrogen utilization efficiencies (N.U.E.) and biomass assimilation efficiencies (A.D.) on both the cyanogenic and acyanogenic plants.Although useful as a deterrent to some herbivores, cyanogenesis does not seem to provide an effective defense against this "adapted" herbivore. This study supports current hypotheses of insect/plant coevolution, and suggests that the metabolic costs of processing cyanogenic plant biomass are small in comparison to those imposed by the nutritional status of the plant leaves.

Enhancement of the complete autotrophic nitrogen removal over nitrite process in a modified single-stage subsurface vertical flow constructed wetland: Effect of saturated zone depth.

Science.gov (United States)

Huang, Menglu; Wang, Zhen; Qi, Ran

2017-06-01

This study was conducted to explore enhancement of the complete autotrophic nitrogen removal over nitrite (CANON) process in a modified single-stage subsurface vertical flow constructed wetland (VSSF) with saturated zone, and nitrogen transformation pathways in the VSSF treating digested swine wastewater were investigated at four different saturated zone depths (SZDs). SZD significantly affected nitrogen transformation pathways in the VSSF throughout the experiment. As the SZD was 45cm, the CANON process was enhanced most effectively in the system owing to the notable enhancement of anammox. Correspondingly, the VSSF had the best TN removal performance [(76.74±7.30)%] and lower N 2 O emission flux [(3.50±0.22)mg·(m 2 ·h) - 1 ]. It could be concluded that autotrophic nitrogen removal via CANON process could become a primary route for nitrogen removal in the VSSF with optimized microenvironment that developed as a result of the appropriate SZD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetic variability in uptake of nitrogen at various growth stages of barley and wheat under dryland conditions

International Nuclear Information System (INIS)

Della, A.; Hadjichristodoulou, A.

1976-01-01

Protein and dry matter in a number of high protein and commercial varieties of barley and wheat were tested at various growth stages and at two locations. Large genetic variability was found in uptake of nitrogen, which was taken up generally before heading. High protein yields were not associated with high protein content but with higher dry matter yields. Nitrogen fertilization increased protein content and protein yield at a low protein location only. It was concluded that it is possible to breed for both high grain and high straw protein varieties. (author)

Effect of nitrogen source and acclimatization on specific growth rates of microalgae determined by a high-throughput in vivo microplate autofluorescence method

DEFF Research Database (Denmark)

Podevin, Mike; De Francisci, Davide; Holdt, Susan Løvstad

2015-01-01

SGRs of the second and third cultivations. ANOVA of SGRs in the acclimatized second and third cultivations revealed preferences for nitrogen sources among most of the algae; C. vulgaris preferred sodiumnitrate over other nitrogen sources, A. protothecoides adapted to urea after no growth in the first...

Isotopic separation of nitrogen 15. Influence of the gaseous phase composition

International Nuclear Information System (INIS)

Lacoste, Germain; Routie, Rene; Mahenc, Jean

1977-01-01

A study has been made on the gas phase composition effect on the isotopic separation of nitrogen 15 for the two HNO 3 -NO and N 2 O 3 -NO systems. It was shown that the changes in composition of the gas phases could account for the increase in the overall separation; most accuracy, measurements of isotopic concentration along the separation column and of total enrichment exhibit how important are the reactions of oxydo-reduction between the two phases in such process [fr

Elevated CO2 and water addition enhance nitrogen turnover in grassland plants with implications for temporal stability.

Science.gov (United States)

Dijkstra, Feike A; Carrillo, Yolima; Blumenthal, Dana M; Mueller, Kevin E; LeCain, Dan R; Morgan, Jack A; Zelikova, Tamara J; Williams, David G; Follett, Ronald F; Pendall, Elise

2018-05-01

Temporal variation in soil nitrogen (N) availability affects growth of grassland communities that differ in their use and reuse of N. In a 7-year-long climate change experiment in a semi-arid grassland, the temporal stability of plant biomass production varied with plant N turnover (reliance on externally acquired N relative to internally recycled N). Species with high N turnover were less stable in time compared to species with low N turnover. In contrast, N turnover at the community level was positively associated with asynchrony in biomass production, which in turn increased community temporal stability. Elevated CO 2 and summer irrigation, but not warming, enhanced community N turnover and stability, possibly because treatments promoted greater abundance of species with high N turnover. Our study highlights the importance of plant N turnover for determining the temporal stability of individual species and plant communities affected by climate change. © 2018 John Wiley & Sons Ltd/CNRS.

Problem of formation of nitrogen oxides during coal combustion in power plant steam generators

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.; Kuvaev, Yu.V.

1992-07-01

Analyzes a study of physical and chemical processes of nitrogen oxide formation during coal combustion conducted at Stanford University (USA). Experimental installation, pulverized coal feeding as well as measuring techniques and equipment are described. Experiments were conducted with 55 micron particles of semibituminous coal. An equation for the percentage of coal carbon converted to gaseous products is given. Active formation of NO from nitrogen content in the fuel was observed when oxygen content was under 4%. Conversion of the fuel nitrogen to NO[sub x] in the 1,350-1,850 K temperature range did not depend on gas temperature but rather on oxygen content. 2 refs.

Laterally enhanced growth of electrodeposited Au to form ultrathin films on nonconductive surfaces

International Nuclear Information System (INIS)

Kobayashi, Chiaki; Saito, Mikiko; Homma, Takayuki

2012-01-01

We investigated the laterally enhanced growth of electrodeposited Au for fabricating nanogap electrodes. To enhance the lateral growth, we carried out electrodeposition over patterned electrodes onto a SiO 2 surface modified with self-assembled monolayers (SAMs) or dendrimers with amine groups. The morphology and thickness of the Au films were controlled by adjusting deposition conditions such as duration, applied potential, and Au ion concentration in the bath. To investigate the mechanism of the laterally enhanced growth, the surface states of SAM- or dendrimer-modified SiO 2 were analyzed by X-ray photoelectron spectroscopy (XPS). The XPS results indicate the existence of organic molecules and Au ions on the SiO 2 surface, which suggests that laterally enhanced growth is induced by the Au ions coordinated on the amine groups of the organic molecules. To further analyze the mechanism of the laterally enhanced growth, we investigated the relationship between the morphology of the laterally enhanced growth of Au and the amount of Au ions on organic molecules. The laterally enhanced growth of Au is expected to be useful for fabricating thin film nanogap electrodes.

INTERACTIONS BETWEEN SOIL TEMPERATURE AND PLANT GROWTH STAGE ON NITROGEN UPTAKE AND AMINO ACID CONTENT OF APPLE NURSERY STOCK DURING EARLY SPRING GROWTH

Science.gov (United States)

In the spring, nitrogen (N) uptake by apple roots is known to be delayed about three weeks after bud break. We used one-year-old 'Fuji' (Malus domestica Borkh) on M26 bare-root apple trees to determine whether timing of N uptake in the spring is dependant solely on the growth st...

Nitrogen fixation in Red Sea seagrass meadows

KAUST Repository

Abdallah, Malak

2017-05-01

Seagrasses are key coastal ecosystems, providing many ecosystem services. Seagrasses increase biodiversity as they provide habitat for a large set of organisms. In addition, their structure provides hiding places to avoid predation. Seagrasses can grow in shallow marine coastal areas, but several factors regulate their growth and distribution. Seagrasses can uptake different kinds of organic and inorganic nutrients through their leaves and roots. Nitrogen and phosphorous are the most important nutrients for seagrass growth. Biological nitrogen fixation is the conversion of atmospheric nitrogen into ammonia by diazotrophic bacteria. This process provides a significant source of nitrogen for seagrass growth. The nitrogen fixation is controlled by the nif genes which are found in diazotrophs. The main goal of the project is to measure nitrogen fixation rates on seagrass sediments, in order to compare among various seagrass species from the Red Sea. Moreover, we will compare the fixing rates of the Vegetated areas with the bare sediments. This project will help to ascertain the role of nitrogen fixing bacteria in the development of seagrass meadows.

Comparison of plasma generated nitrogen fertilizer to conventional fertilizers ammonium nitrate and sodium nitrate for pre-emergent and seedling growth

Science.gov (United States)

Andhavarapu, A.; King, W.; Lindsay, A.; Byrns, B.; Knappe, D.; Fonteno, W.; Shannon, S.

2014-10-01

Plasma source generated nitrogen fertilizer is compared to conventional nitrogen fertilizers in water for plant growth. Root, shoot sizes, and weights are used to examine differences between plant treatment groups. With a simple coaxial structure creating a large-volume atmospheric glow discharge, a 162 MHz generator drives the air plasma. The VHF plasma source emits a steady state glow; the high drive frequency is believed to inhibit the glow-to-arc transition for non-thermal discharge generation. To create the plasma activated water (PAW) solutions used for plant treatment, the discharge is held over distilled water until a 100 ppm nitrate aqueous concentration is achieved. The discharge is used to incorporate nitrogen species into aqueous solution, which is used to fertilize radishes, marigolds, and tomatoes. In a four week experiment, these plants are watered with four different solutions: tap water, dissolved ammonium nitrate DI water, dissolved sodium nitrate DI water, and PAW. Ammonium nitrate solution has the same amount of total nitrogen as PAW; sodium nitrate solution has the same amount of nitrate as PAW. T-tests are used to determine statistical significance in plant group growth differences. PAW fertilization chemical mechanisms are presented.

Interaction of oxides of nitrogen and aromatic hydrocarbons under simulated atmospheric conditions

International Nuclear Information System (INIS)

Obrien, R.J.; Green, P.J.; Doty, R.A.; Vanderzanden, J.W.; Easton, R.R.; Irwin, R.P.

1979-01-01

The reactions of nitrogen oxides with aromatic hydrocarbons under simulated atmospheric conditions are investigated. Gaseous reaction products formed when toluene is irradiated under simulated atmospheric conditions in the presence of nitrogen oxides were analyzed by gas chromatography. Reaction products detected include acetylene, water, acetaldehyde, acetone, toluene, benzaldehyde, ortho-, meta- and para-cresol, benzyl nitrate and meta- and para-nitrotoluene. Reaction mechanisms yielding the various products are illustrated. The assumption that all the nitrogen oxides observed to be lost from the reaction products can be accounted for by nitric acid formation in the absence of ozone formation is verified by a model in which the hydroxyl radical is assumed to be the only means of removing toluene. Under conditions in which ozone is formed, nitrogen oxide loss is accounted for by ozone formation in addition to nitric acid formation

Simulating antler growth and energy, nitrogen, calcium and phosphorus metabolism in caribou

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Ron Moen

1998-03-01

Full Text Available We added antler growth and mineral metabolism modules to a previously developed energetics model for ruminants to simulate energy and mineral balance of male and female caribou throughout an annual cycle. Body watet, fat, protein, and ash are monitored on a daily time step, and energy costs associated with reproduction and body mass changes are simulated. In order to simulate antler growth, we had to predict calcium and phosphorus metabolism as it is affected by antler growth, gestation, and lactation. We used data on dietary digestibility, protein, calcium and phosphorus content, and seasonal patterns in body mass to predict the energy, nitrogen, calcium, and phosphorus balances of a "generic" male and female caribou. Antler growth in males increased energy requirements during antler growth by 8 to 16%, depending on the efficiency with which energy was used for antler growth. Female energy requirements for antler growth were proportionately much smaller because of the smaller size of female antlers. Protein requirements for antler growth in both males and females were met by forage intake. Calcium and phosphorus must be resorbed from bone during peak antler growth in males, when > 25 g/day of calcium and > 12 g/day of phosphorus are being deposited in antlers. Females are capable of meeting calcium needs during antler growth without bone resorption, but phosphorus was resorbed from bone during the final stages of antler mineralization. After energy, phosphorus was most likely to limit growth of antlers for both males and females in our simulations. Input parameters can be easily changed to represent caribou from specific geographic regions in which dietary nutrient content or body mass patterns differ from those in our "generic" caribou. The model can be used to quantitatively analyze the evolutionary basis for development of antlers in female caribou, and the relationship between body mass and antler size in the Cervidae.

Combined effects of enhanced UV-B radiation and nitrogen deficiency on the growth, composition and photosynthesis of rye (Secale cereale)

International Nuclear Information System (INIS)

Deckmyn, G.; Impens, I.

1997-01-01

The interactive effects of N-deficiency and enhanced UV-B radiation on growth, photosynthesis and pigmentation of rye were studied. The plants were grown for 5 weeks in growth chambers with high (700 μmol m -2 s -2 ) irradiance levels. A 30% difference in UV-B at plant level was achieved by using different thicknesses of UV-B transparent Plexiglass. One half of the plants received optimal N nutrition, while the other received half of this dose. Both enhanced UV-B and N deficiency strongly decreased production (from 24–33%). The combined effect was additive (no interaction) on most parameters, including total dry weight production which was 52% lower than in the control series. Significant interaction was found on the root/shoot ratio. While reduced N supply induced an increase in the ratio at normal UV-B irradiation, under the increased UV-B, N deficiency had no effect on the root/shoot ratio. The reduced biomass due to UV-B was clearly correlated to a reduction in photosynthesis. At optimal N supply the plants increased the production of protective pigments in response to UV-B, but at reduced N supply this response was lacking. The increased N content of the high UV-B/high N plants could be a result of increased flavonoid production as well as changes in light penetration in the canopy. (author)

The Effect of Nitrogen Form on pH and Petunia Growth in a WholeTree Substrate

Science.gov (United States)

The objective of our research was to investigate the effect of nitrogen form and proportion on peat-lite (PL) and WholeTree (WT) substrate pH and petunia growth. Chipped whole pine trees (consisting of needles, limbs, bark, wood and cones) were obtained from a commercial fuel wood chipping operation...

A case study of the relative effects of power plant nitrogen oxides and sulfur dioxide emission reductions on atmospheric nitrogen deposition.

Science.gov (United States)

Vijayaraghavan, Krish; Seigneur, Christian; Bronson, Rochelle; Chen, Shu-Yun; Karamchandani, Prakash; Walters, Justin T; Jansen, John J; Brandmeyer, Jo Ellen; Knipping, Eladio M

2010-03-01

The contrasting effects of point source nitrogen oxides (NOx) and sulfur dioxide (SO2) air emission reductions on regional atmospheric nitrogen deposition are analyzed for the case study of a coal-fired power plant in the southeastern United States. The effect of potential emission reductions at the plant on nitrogen deposition to Escambia Bay and its watershed on the Florida-Alabama border is simulated using the three-dimensional Eulerian Community Multiscale Air Quality (CMAQ) model. A method to quantify the relative and individual effects of NOx versus SO2 controls on nitrogen deposition using air quality modeling results obtained from the simultaneous application of NOx and SO2 emission controls is presented and discussed using the results from CMAQ simulations conducted with NOx-only and SO2-only emission reductions; the method applies only to cases in which ambient inorganic nitrate is present mostly in the gas phase; that is, in the form of gaseous nitric acid (HNO3). In such instances, the individual effects of NOx and SO2 controls on nitrogen deposition can be approximated by the effects of combined NOx + SO2 controls on the deposition of NOy, (the sum of oxidized nitrogen species) and reduced nitrogen species (NHx), respectively. The benefit of controls at the plant in terms of the decrease in nitrogen deposition to Escambia Bay and watershed is less than 6% of the overall benefit due to regional Clean Air Interstate Rule (CAIR) controls.

Effects of Nitrification Inhibitors and Sulphur Coated Urea(SCU on Different Nitrogen Sources and Wheat Yield

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LI Yong-qiang

2016-05-01

Full Text Available Nitrogen is essential for plant growth and health, and it is also a limiting factor for the growth in most agricultural systems. Intensive N fertilizer application has become the traditional habit for agricultural producers in China because of its importance to plant productivity and agricultural land profitability. But some problems have appeared with the increase of the amount of nitrogen fertilizer applied, urea used in crops is easy to lose from volatilization or leaching. Therefore, current crop management practices lead to a highly nitrifying soil environments. Nitrogen emission is the main source of soil acidity and environmental pollution. Several methods for the use of slow controlled release urea have been reported to be used to control the pollution and to enhance nitrogen use efficiency. There is a growing interest in the formulations of coated chemical fertilizers with both urease inhibitor and nitrification inhibitor. Urease inhibitor and nitrification inhibitor may improve urea N-use efficiency and minimize N losses by gaseous emissions of ammonia(NH3 to the atmosphere and nitrate(NO3- leaching into the surface and ground water. Dicyandiamide(DCD is a nitrification inhibitor that has been studied for many years, it can effectively inhibit nitrification and N2O emission in many agricultural ecosystems. However, limited information is available on the use of the combination of nitrification inhibitor and urease inhibitor applied with urea fertilizer, especially for thiourea(THU and thiourea formaldehyde resin(TFR applications. Therefore the purpose of this study is to investigate the effect of urea with different inhibitors to improve the efficiency of nitrogen utilization. A field pot experiment was conducted to explore how to increase the concentration of DCD/THU/TFR/sulfur-coated urea(SCU to affect the transformation of soil nitrogen and wheat yield. The experiment was designed for twelve treatments which included no nitrogen

H. guilliermondii impacts growth kinetics and metabolic activity of S. cerevisiae: the role of initial nitrogen concentration.

Science.gov (United States)

Lage, Patrícia; Barbosa, Catarina; Mateus, Beatriz; Vasconcelos, Isabel; Mendes-Faia, Arlete; Mendes-Ferreira, Ana

2014-02-17

Non-Saccharomyces yeasts include different species which comprise an ecologically and biochemically diverse group capable of altering fermentation dynamics and wine composition and flavour. In this study, single- and mixed-culture of Hanseniaspora guilliermondii and Saccharomyces cerevisiae were used to ferment natural grape-juice, under two nitrogen regimes. In single-culture the strain H. guilliermondii failed to complete total sugar breakdown even though the nitrogen available has not been a limiting factor of its growth or fermentative activity. In mixed-culture, that strain negatively interfered with the growth and fermentative performance of S. cerevisiae, resulting in lower fermentation rate and longer fermentation length, irrespective of the initial nitrogen concentration. The impact of co-inoculation on the volatile compounds profile was more evident in the wines obtained from DAP-supplemented musts, characterised by increased levels of ethyl and acetate esters, associated with fruity and floral character of wines. Moreover, the levels of fatty acids and sulphur compounds which are responsible for unpleasant odours that depreciate wine sensory quality were significantly lower. Accordingly, data obtained suggests that the strain H. guilliermondii has potential to be used as adjunct of S. cerevisiae in wine industry, although possible interactions with S. cerevisiae still need to be elucidated. Copyright © 2013 Elsevier B.V. All rights reserved.

Treatment of Radioactive Gaseous Waste

International Nuclear Information System (INIS)

2014-07-01

Radioactive waste, with widely varying characteristics, is generated from the operation and maintenance of nuclear power plants, nuclear fuel cycle facilities, research laboratories and medical facilities. The waste needs to be treated and conditioned as necessary to provide waste forms acceptable for safe storage and disposal. Although radioactive gaseous radioactive waste does not constitute the main waste flow stream at nuclear fuel cycle and radioactive waste processing facilities, it represents a major source for potential direct environmental impact. Effective control and management of gaseous waste in both normal and accidental conditions is therefore one of the main issues of nuclear fuel cycle and waste processing facility design and operation. One of the duties of an operator is to take measures to avoid or to optimize the generation and management of radioactive waste to minimize the overall environmental impact. This includes ensuring that gaseous and liquid radioactive releases to the environment are within authorized limits, and that doses to the public and the effects on the environment are reduced to levels that are as low as reasonably achievable. Responsibilities of the regulatory body include the removal of radioactive materials within authorized practices from any further regulatory control — known as clearance — and the control of discharges — releases of gaseous radioactive material that originate from regulated nuclear facilities during normal operation to the environment within authorized limits. These issues, and others, are addressed in IAEA Safety Standards Series Nos RS-G-1.7, WS-G-2.3 and NS-G-3.2. Special systems should be designed and constructed to ensure proper isolation of areas within nuclear facilities that contain gaseous radioactive substances. Such systems consist of two basic subsystems. The first subsystem is for the supply of clean air to the facility, and the second subsystem is for the collection, cleanup and

Chemical vapor deposition growth of boron-carbon-nitrogen layers from methylamine borane thermolysis products

Science.gov (United States)

Leardini, Fabrice; Flores, Eduardo; Galvis E, Andrés R.; Ferrer, Isabel J.; Ramón Ares, José; Sánchez, Carlos; Molina, Pablo; van der Meulen, Herko P.; Gómez Navarro, Cristina; López Polin, Guillermo; Urbanos, Fernando J.; Granados, Daniel; García-García, F. Javier; Demirci, Umit B.; Yot, Pascal G.; Mastrangelo, Filippo; Grazia Betti, Maria; Mariani, Carlo

2018-01-01

This work investigates the growth of B-C-N layers by chemical vapor deposition using methylamine borane (MeAB) as the single-source precursor. MeAB has been synthesized and characterized, paying particular attention to the analysis of its thermolysis products, which are the gaseous precursors for B-C-N growth. Samples have been grown on Cu foils and transferred onto different substrates for their morphological, structural, chemical, electronic and optical characterizations. The results of these characterizations indicate a segregation of h-BN and graphene-like (Gr) domains. However, there is an important presence of B and N interactions with C at the Gr borders, and of C interacting at the h-BN-edges, respectively, in the obtained nano-layers. In particular, there is a significant presence of C-N bonds, at Gr/h-BN borders and in the form of N doping of Gr domains. The overall B:C:N contents in the layers is close to 1:3:1.5. A careful analysis of the optical bandgap determination of the obtained B-C-N layers is presented, discussed and compared with previous seminal works with samples of similar composition.

Soil Microbial Communities and Gas Dynamics Contribute to Arbuscular Mycorrhizal Nitrogen Uptake and Transfer to Plants

Science.gov (United States)

Hestrin, R.; Harrison, M. J.; Lehmann, J.

2016-12-01

Arbuscular mycorrhizal fungi (AMF) associate with most terrestrial plants and influence ecosystem ecology and biogeochemistry. There is evidence that AMF play a role in soil nitrogen cycling, in part by taking up nitrogen and transferring it to plants. However, many aspects of this process are poorly understood, including the factors that control fungal access to nitrogen stored in soil organic matter. In this study, we used stable isotopes and root exclusion to track nitrogen movement from organic matter into AMF and host plants. AMF significantly increased total plant biomass and nitrogen content, but both AMF and other soil microbes seemed to compete with plants for nitrogen. Surprisingly, gaseous nitrogen species also contributed significantly to plant nitrogen content under alkaline soil conditions. Our current experiments investigate whether free-living microbial communities that have evolved under a soil nitrogen gradient influence AMF access to soil organic nitrogen and subsequent nitrogen transfer to plants. This research links interactions between plants, mycorrhizal symbionts, and free-living microbes with terrestrial carbon and nitrogen dynamics.

Minimally invasive esthetic ridge preservation with growth-factor enhanced bone matrix.

Science.gov (United States)

Nevins, Marc L; Said, Sherif

2017-12-28

Extraction socket preservation procedures are critical to successful esthetic implant therapy. Conventional surgical approaches are technique sensitive and often result in alteration of the soft tissue architecture, which then requires additional corrective surgical procedures. This case series report presents the ability of flapless surgical techniques combined with a growth factor-enhanced bone matrix to provide esthetic ridge preservation at the time of extraction for compromised sockets. When considering esthetic dental implant therapy, preservation, or further enhancement of the available tissue support at the time of tooth extraction may provide an improved esthetic outcome with reduced postoperative sequelae and decreased treatment duration. Advances in minimally invasive surgical techniques combined with recombinant growth factor technology offer an alternative for bone reconstruction while maintaining the gingival architecture for enhanced esthetic outcome. The combination of freeze-dried bone allograft (FDBA) and rhPDGF-BB (platelet-derived growth factor-BB) provides a growth-factor enhanced matrix to induce bone and soft tissue healing. The use of a growth-factor enhanced matrix is an option for minimally invasive ridge preservation procedures for sites with advanced bone loss. Further studies including randomized clinical trials are needed to better understand the extent and limits of these procedures. The use of minimally invasive techniques with growth factors for esthetic ridge preservation reduces patient morbidity associated with more invasive approaches and increases the predictability for enhanced patient outcomes. By reducing the need for autogenous bone grafts the use of this technology is favorable for patient acceptance and ease of treatment process for esthetic dental implant therapy. © 2017 Wiley Periodicals, Inc.

Low nitrogen stress stimulating the indole-3-acetic acid biosynthesis of Serratia sp. ZM is vital for the survival of the bacterium and its plant growth-promoting characteristic.

Science.gov (United States)

Ouyang, Liming; Pei, Haiyan; Xu, Zhaohui

2017-04-01

Serratia sp. ZM is a plant growth-promoting (PGP) bacterial strain isolated from the rhizospheric soil of Populus euphratica in northwestern China. In this study, low nitrogen supply significantly stimulated the production of indole-3-acetic acid (IAA) in Serratia sp.ZM. The inoculation of the bacterium to wheat seedlings improved plant growth compared with the uninoculated group, and the stimulating effect was more prominent under low nitrogen stress. Inactivation of the predicted key gene in the IAA biosynthesis pathway impaired IAA production and significantly hampered mutant growth in poor medium. Furthermore, the IAA-deficient mutant lost the PGP effect under either normal or low nitrogen conditions in plant experiments. This study revealed the significant impact of environmental nitrogen levels on IAA production in the PGP strain and the vital effect of IAA on resistance physiology of both the bacterium and host plant. The characteristics of Serratia sp. ZM also indicated its application potential as a biofertilizer for plants, especially those suffering from poor nitrogen soil.

Growth Kinetics of Diazotrophic Bacillus sphaericus UPMB10 Cultured Using Different Types and Concentrations of Carbon and Nitrogen Sources

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Ooi, T. C.

2008-01-01

Full Text Available Growth kinetics of newly isolated diazotrophic Bacillus sphaericus UPMB10 grown in various carbon (lactate, acetate, glycerol, malate, fructose, xylose and sucrose and nitrogen (glutamate, yeast extract, arginine, hystadine, glycine, polypeptone, tryptophan, lysine, NH4Cl and urea sources was investigated using 2 L stirred tank fermenter. The highest growth was obtained in a medium containing lactate as a carbon source, which gave the highest maximum cell concentration of 2.30 g/L, which is corresponding to maximum viable cell count of 4.60 x 10^9 cfu/mL. However, the highest cell yield (1.06 g cell/g carbon consumed was obtained in cultivation using glycerol though slightly lower maximum viable cell count was obtained (3.22 x 10^9 cfu/mL. In addition, cost for the production of live cell using glycerol was about 15 times lower than the cost using lactate. Growth performance of this bacterium when yeast extract was used as a nitrogen source was comparable to the use of pure amino acid. The medium containing 1.8 g/L glycerol and 2 g/L yeast extract was suggested as optimal for growth of this bacterium, which gave carbon to nitrogen ratio (C/N of 10:1. The maximum viable cell count obtained in cultivation using optimised medium in 2 L stirred tank fermenter was 3.34 x 10^9 cfu/mL and the cells maintained its capacity for N2 fixation at 18 nmol C2H2/h.mL.

Applied electric field enhances DRG neurite growth: influence of stimulation media, surface coating and growth supplements

Science.gov (United States)

Wood, Matthew D.; Willits, Rebecca Kuntz

2009-08-01

Electrical therapies have been found to aid repair of nerve injuries and have been shown to increase and direct neurite outgrowth during stimulation. This enhanced neural growth existed even after the electric field (EF) or stimulation was removed, but the factors that may influence the enhanced growth, such as stimulation media or surface coating, have not been fully investigated. This study characterized neurite outgrowth and branching under various conditions: EF magnitude and application time, ECM surface coating, medium during EF application and growth supplements. A uniform, low-magnitude EF (24 or 44 V m-1) was applied to dissociated chick embryo dorsal root ganglia seeded on collagen or laminin-coated surfaces. During the growth period, cells were either exposed to NGF or N2, and during stimulation cells were exposed to either unsupplemented media (Ca2+) or PBS (no Ca2+). Parallel controls for each experiment included cells exposed to the chamber with no stimulation and cells remaining outside the chamber. After brief electrical stimulation (10 min), neurite length significantly increased 24 h after application for all conditions studied. Of particular interest, increased stimulation time (10-100 min) further enhanced neurite length on laminin but not on collagen surfaces. Neurite branching was not affected by stimulation on any surface, and no preferential growth of neurites was noted after stimulation. Overall, the results of this report suggest that short-duration electric stimulation is sufficient to enhance neurite length under a variety of conditions. While further data are needed to fully elucidate a mechanism for this increased growth, these data suggest that one focus of those investigations should be the interaction between the growth cone and the substrata.

Effect of some plant growth promoting rhizobacteria and nitrogen fertilizer on morphological characteristics of german chamomile (Matricaria chamomilla L.

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S. Dastborhan

2016-04-01

Full Text Available .In order to investigate the effects of plant growth promoting rhizobacteria and nitrogen fertilizer on morphological traits of german chamomile (Matricaria chamomilla L., a field experiment was carried out as factorial based on randomized complete block design with three replications in Research Farm of the Faculty of Agriculture, University of Tabriz, Iran, during 2007-2008. Factors were inoculation with plant growth promoting rhizobacteria (B0: no-inoculation, B1: inoculation with Azotobacter chroocuccum, B2: inoculation with Azospirillum lipoferum and B3: inoculation with a mixture of two bacteria and nitrogen fertilizer (N0:0, N1:50, N2:100 and N3:150 kgN.ha-1. Results showed that inoculation with bacteria significantly improved plant height, stem diameter, number of lateral branches, number of flowers per plant, dry weight of flowers, stems, leaves and total dry weight per plant. These traits were significantly similar for inoculation with Azotobacter, inoculation with Azospirillum and inoculation with a mixture of two bacteria. Effect of nitrogen fertilizer on all traits (except number of lateral branches was positive, but there were no significant differences among 50, 100 and 150 kg.ha-1 nitrogen. The highest and the lowest number and weight of flowers per plant were recorded for inoculation + 50 kg.ha-1 nitrogen application and no-inoculation + no-fertilizer, respectively. In general, application of biofertilizers had positive and significant effects on morphological traits of german chamomile. In addition, with adding 50 kg N.ha-1 the performance of bacteria increased and the highest flower yield were produced.

Plant growth promoting potential and phylogenetic characteristics of a lichenized nitrogen fixing bacterium, Enterobacter cloacae.

Science.gov (United States)

Swamy, Chidanandamurthy Thippeswamy; Gayathri, Devaraja; Devaraja, Thimmalapura Neelakantaiah; Bandekar, Mandar; D'Souza, Stecy Elvira; Meena, Ram Murti; Ramaiah, Nagappa

2016-12-01

Lichens are complex symbiotic association of mycobionts, photobionts, and bacteriobionts, including chemolithotropic bacteria. In the present study, 46 lichenized bacteria were isolated by conventional and enrichment culture methods on nitrogen-free bromothymol blue (NFb) medium. Only 11 of the 46 isolates fixed nitrogen on NFb and had reduced acetylene. All these 11 isolates had also produced siderophore and 10 of them the IAA. Further, ammonia production was recorded from nine of these nitrogen fixers (NF). On molecular characterization, 16 S rRNA sequencing recorded that, nine NF belonged to Proteobacteria, within Gammaproteobacteria, and were closely related to Enterobacter sp. with a maximum similarity to Enterobacter cloacae. Each one of our NF isolates was aligned closely to Enterobacter pulveris strain E443, Cronobacter sakazakii strain PNP8 and Providencia rettgeri strain ALK058. Notably, a few strains we examined found to possess plant growth promoting properties. This is the first report of Enterobacter sp. from lichens which may be inhabit lichen thalli extrinsically or intrinsically. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Changes in susceptibility of beech (Fagus sylvatica) seedlings towards Phytophthora citricola under the influence of elevated atmospheric CO2 and nitrogen fertilization

International Nuclear Information System (INIS)

Fleischmann, F.; Raidl, S.; Osswald, W.F.

2010-01-01

The growth-differentiation balance hypothesis (GDBH) predicts changes in susceptibility of plants against herbivores with changing resource availability. In the presented study we tested the validity of the GDBH for trees infected with a root pathogen. For this purpose Fagus sylvatica seedlings grown under different atmospheric CO 2 - and soil nitrogen regimes were infected with the root pathogen Phytophthora citricola. High nitrogen supply increased total biomass of beech regardless of the CO 2 -treatment, whereas elevated CO 2 enhanced biomass only in the high nitrogen treatment. The responses of beech under the different growing regimes to the Phytophthora root infection were not in line with the predictions of the GDBH. Enhanced susceptibility of beech against P. citricola was found in seedlings grown under elevated CO 2 and low nitrogen supply. Fifteen months after inoculation these plants were characterized by enhanced water use efficiency, by altered root-shoot ratios, and by enhanced specific root tip densities. - Susceptibility of Fagus sylvatica to the root pathogen Phytophthora citricola increased under elevated CO 2

Assessing the impacts of climate change and nitrogen deposition on Norway spruce growth in Austria with BIOME-BGC

Energy Technology Data Exchange (ETDEWEB)

Eastaugh, Chris S.; Potzelsberger, Elisabeth; Hasenaueur, Hubert

2011-03-15

The purpose of this study is to determine if the climate change has had an apparent impact in Austrian forests. This research has been conducted on Norway spruce forests as this is the predominant species in Austria. Growth data between regions which have different temperature and precipitation trendsw was then compared, with results showing increased productivity in all regions thus implying that growth of the forest is driven by other factors than climate. This conclusion is consistent with previous studies supporting that forest growth is mainly driven by increasing nitrogen deposition.

Growth but not photosynthesis response of a host plant to infection by a holoparasitic plant depends on nitrogen supply.

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Hao Shen

Full Text Available Parasitic plants can adversely influence the growth of their hosts by removing resources and by affecting photosynthesis. Such negative effects depend on resource availability. However, at varied resource levels, to what extent the negative effects on growth are attributed to the effects on photosynthesis has not been well elucidated. Here, we examined the influence of nitrogen supply on the growth and photosynthesis responses of the host plant Mikania micrantha to infection by the holoparasite Cuscuta campestris by focusing on the interaction of nitrogen and infection. Mikania micrantha plants fertilized at 0.2, 1 and 5 mM nitrate were grown with and without C. campestris infection. We observed that the infection significantly reduced M. micrantha growth at each nitrate fertilization and more severely at low than at high nitrate. Such alleviation at high nitrate was largely attributed to a stronger influence of infection on root biomass at low than at high nitrate fertilization. However, although C. campestris altered allometry and inhibited host photosynthesis, the magnitude of the effects was independent of nitrate fertilizations. The infection reduced light saturation point, net photosynthesis at saturating irradiances, apparent quantum yield, CO2 saturated rate of photosynthesis, carboxylation efficiency, the maximum carboxylation rate of Rubisco, and maximum light-saturated rate of electron transport, and increased light compensation point in host leaves similarly across nitrate levels, corresponding to a similar magnitude of negative effects of the parasite on host leaf soluble protein and Rubisco concentrations, photosynthetic nitrogen use efficiency and stomatal conductance across nitrate concentrations. Thus, the more severe inhibition in host growth at low than at high nitrate supplies cannot be attributed to a greater parasite-induced reduction in host photosynthesis, but the result of a higher proportion of host resources

Growth but Not Photosynthesis Response of a Host Plant to Infection by a Holoparasitic Plant Depends on Nitrogen Supply

Science.gov (United States)

Shen, Hao; Xu, Shu-Jun; Hong, Lan; Wang, Zhang-Ming; Ye, Wan-Hui

2013-01-01

Parasitic plants can adversely influence the growth of their hosts by removing resources and by affecting photosynthesis. Such negative effects depend on resource availability. However, at varied resource levels, to what extent the negative effects on growth are attributed to the effects on photosynthesis has not been well elucidated. Here, we examined the influence of nitrogen supply on the growth and photosynthesis responses of the host plant Mikania micrantha to infection by the holoparasite Cuscuta campestris by focusing on the interaction of nitrogen and infection. Mikania micrantha plants fertilized at 0.2, 1 and 5 mM nitrate were grown with and without C. campestris infection. We observed that the infection significantly reduced M. micrantha growth at each nitrate fertilization and more severely at low than at high nitrate. Such alleviation at high nitrate was largely attributed to a stronger influence of infection on root biomass at low than at high nitrate fertilization. However, although C. campestris altered allometry and inhibited host photosynthesis, the magnitude of the effects was independent of nitrate fertilizations. The infection reduced light saturation point, net photosynthesis at saturating irradiances, apparent quantum yield, CO2 saturated rate of photosynthesis, carboxylation efficiency, the maximum carboxylation rate of Rubisco, and maximum light-saturated rate of electron transport, and increased light compensation point in host leaves similarly across nitrate levels, corresponding to a similar magnitude of negative effects of the parasite on host leaf soluble protein and Rubisco concentrations, photosynthetic nitrogen use efficiency and stomatal conductance across nitrate concentrations. Thus, the more severe inhibition in host growth at low than at high nitrate supplies cannot be attributed to a greater parasite-induced reduction in host photosynthesis, but the result of a higher proportion of host resources transferred to the parasite at

Dissociation dynamics of anionic and excited neutral fragments of gaseous SiCl4 following Cl 2p and Si 2p core-level excitations

International Nuclear Information System (INIS)

Chen, J M; Lu, K T; Lee, J M; Chou, T L; Chen, H C; Chen, S A; Haw, S C; Chen, T H

2008-01-01

The state-selective dissociation dynamics for anionic and excited neutral fragments of gaseous SiCl 4 following Cl 2p and Si 2p core-level excitations were characterized by combining measurements of the photon-induced anionic dissociation, x-ray absorption and UV/visible dispersed fluorescence. The transitions of core electrons to high Rydberg states/doubly excited states in the vicinity of both Si 2p and Cl 2p ionization thresholds of gaseous SiCl 4 lead to a remarkably enhanced production of anionic, Si - and Cl - , fragments and excited neutral atomic, Si*, fragments. This enhancement via core-level excitation near the ionization threshold of gaseous SiCl 4 is explained in terms of the contributions from the Auger decay of doubly excited states, shake-modified resonant Auger decay, or/and post-collision interaction. These complementary results provide insight into the state-selective anionic and excited neutral fragmentation of gaseous molecules via core-level excitation.

Identification of genotypic variation for nitrogen response in potato (Solanum tuberosum) under low nitrogen input circumstances

OpenAIRE

Tiemens-Hulscher, M.; Lammerts Van Bueren, E.; Struik, P.C.

2009-01-01

Nitrogen is an essential nutrient for crop growth. The demand for nitrogen in the potato crop is relatively high. However, in organic farming nitrogen input is rather limited, compared with conventional farming. In this research nine potato varieties were tested at three nitrogen levels. Genotypic variation for yield, leaf area index, period of maximum soil cover, sensitivity for N-shortage and nitrogen efficiency under low input circumstances was found. However, in these experiments varietie...

Dielectrophoretic separation of gaseous isotopes

International Nuclear Information System (INIS)

McConnell, D.B.

1976-01-01

This invention relates to a process for the separation of gaseous isotopes by electrophoresis assisted by convective countercurrent flow and to an apparatus for use in the process. The invention is especially applicable to heavy water separation from steam; however, it is to be understood that the invention is broadly applicable to the separation of gaseous isotopes having different dipole moments and/or different molecular weights. (author)

Coupled effects of methane monooxygenase and nitrogen source on growth and poly-β-hydroxybutyrate (PHB) production of Methylosinus trichosporium OB3b.

Science.gov (United States)

Zhang, Tingting; Zhou, Jiti; Wang, Xiaowei; Zhang, Yu

2017-02-01

The coupled effects of nitrogen source and methane monooxygenase (MMO) on the growth and poly-β-hydroxybutyrate (PHB) accumulation capacity of methanotrophs were explored. The ammonia-supplied methanotrophs expressing soluble MMO (sMMO) grew at the highest rate, while N 2 -fixing bacteria expressing particulate MMO (pMMO) grew at the lowest rate. Further study showed that more hydroxylamine and nitrite was formed by ammonia-supplied bacteria containing pMMO, which might cause their slightly lower growth rate. The highest PHB content (51.0%) was obtained under nitrogen-limiting conditions with the inoculation of nitrate-supplied bacteria containing pMMO. Ammonia-supplied bacteria also accumulated a higher content of PHB (45.2%) with the expression of pMMO, while N 2 -fixing bacteria containing pMMO only showed low PHB production capacity (32.1%). The maximal PHB contents of bacteria expressing sMMO were low, with no significant change under different nitrogen source conditions. The low MMO activity, low cell growth rate and low PHB production capacity of methanotrophs continuously cultivated with N 2 with the expression of pMMO were greatly improved in the cyclic NO 3 - N 2 cultivation regime, indicating that long-term deficiency of nitrogen sources was detrimental to the activity of methanotrophs expressing pMMO. Copyright © 2016. Published by Elsevier B.V.

Growth and Nitrogen Uptake in Sorghum Plants Manured with Leucaena Leucocaphala Leaves as Affected by Nitrogen Rate and Time of Application

International Nuclear Information System (INIS)

Kurd Ali, F.; Al-Shammaa, M.

2011-01-01

A pot experiment was conducted to determine the effect of four rates of nitrogen (N) in the form of leucaena leaves and the time of application on the performance of sorghum plants using the 15 N isotopic dilution technique. Results showed that leucaena green manure (LGM) increased dry matter and N yield of sorghum. Nitrogen recoveries of LGM ranged between 23 and 47%. An additional beneficial effect of LGM was attributed to the enhancement of soil N uptake. The best timing of LGM incorporation for obtaining more N derived from LGM, less soil N uptake, and greater dry matter and N in sorghum leaves seemed to be at planting. However, the appropriate timing and rate of LGM to obtain greater dry matter and N yield in panicles, as well as in the whole plant of sorghum, appeared to be at 30 days before planting, particularly a rate of 120 kg N ha - 1. (author)

Supramolecular Nanofibers Enhance Growth Factor Signaling by Increasing Lipid Raft Mobility

Energy Technology Data Exchange (ETDEWEB)

Newcomb, Christina J.; Sur, Shantanu; Lee, Sungsoo S.; Yu, Jeong Min; Zhou, Yan; Snead, Malcolm L.; Stupp, Samuel I. (NWU); (USC)

2016-04-12

The nanostructures of self-assembling biomaterials have been previously designed to tune the release of growth factors in order to optimize biological repair and regeneration. We report here on the discovery that weakly cohesive peptide nanostructures in terms of intermolecular hydrogen bonding, when combined with low concentrations of osteogenic growth factor, enhance both BMP-2 and Wnt mediated signaling in myoblasts and bone marrow stromal cells, respectively. Conversely, analogous nanostructures with enhanced levels of internal hydrogen bonding and cohesion lead to an overall reduction in BMP-2 signaling. We propose that the mechanism for enhanced growth factor signaling by the nanostructures is related to their ability to increase diffusion within membrane lipid rafts. The phenomenon reported here could lead to new nanomedicine strategies to mediate growth factor signaling for translational targets.

Thermodynamic Modeling and Mechanical Design of a Liquid Nitrogen Vaporization and Pressure Building Device

Science.gov (United States)

Leege, Brian J.

The design of a liquid nitrogen vaporization and pressure building device that has zero product waste while recovering some of its stored energy is of interest for the cost reduction of nitrogen for use in industrial processes. Current devices may waste up to 30% of the gaseous nitrogen product by venting it to atmosphere. Furthermore, no attempt is made to recover the thermal energy available in the coldness of the cryogen. A seven step cycle with changing volumes and ambient heat addition is proposed, eliminating all product waste and providing the means of energy recovery from the nitrogen. This thesis discusses the new thermodynamic cycle and modeling as well as the mechanical design and testing of a prototype device. The prototype was able to achieve liquid nitrogen vaporization and pressurization up to 1000 psi, while full cycle validation is ongoing with promising initial results.

Influence of a gaseous atmosphere on fatigue crack propagation

International Nuclear Information System (INIS)

Henaff, G.

2002-01-01

The paper presents a review of the current knowledge on the influence of gaseous atmospheres, and primarily ambient air, on fatigue crack propagation in metallic alloys. Experimental evidence of the effect of exposure to ambient air or any moist environment on fatigue crack propagation in steels is first proposed. The different interacting processes are analyzed so as to clearly uncouple the influence of the various factors on crack growth resistance. Two distinct mechanisms are identified: the adsorption of vapour molecules and hydrogen assisted fracture at crack tip. (author)

Gene Deletions Resulting in Increased Nitrogen Release by Azotobacter vinelandii: Application of a Novel Nitrogen Biosensor

Science.gov (United States)

Eberhart, Lauren J.; Ohlert, Janet M.; Knutson, Carolann M.; Plunkett, Mary H.

2015-01-01

Azotobacter vinelandii is a widely studied model diazotrophic (nitrogen-fixing) bacterium and also an obligate aerobe, differentiating it from many other diazotrophs that require environments low in oxygen for the function of the nitrogenase. As a free-living bacterium, A. vinelandii has evolved enzymes and transporters to minimize the loss of fixed nitrogen to the surrounding environment. In this study, we pursued efforts to target specific enzymes and further developed screens to identify individual colonies of A. vinelandii producing elevated levels of extracellular nitrogen. Targeted deletions were done to convert urea into a terminal product by disrupting the urease genes that influence the ability of A. vinelandii to recycle the urea nitrogen within the cell. Construction of a nitrogen biosensor strain was done to rapidly screen several thousand colonies disrupted by transposon insertional mutagenesis to identify strains with increased extracellular nitrogen production. Several disruptions were identified in the ammonium transporter gene amtB that resulted in the production of sufficient levels of extracellular nitrogen to support the growth of the biosensor strain. Further studies substituting the biosensor strain with the green alga Chlorella sorokiniana confirmed that levels of nitrogen produced were sufficient to support the growth of this organism when the medium was supplemented with sufficient sucrose to support the growth of the A. vinelandii in coculture. The nature and quantities of nitrogen released by urease and amtB disruptions were further compared to strains reported in previous efforts that altered the nifLA regulatory system to produce elevated levels of ammonium. These results reveal alternative approaches that can be used in various combinations to yield new strains that might have further application in biofertilizer schemes. PMID:25888177

Plant species richness enhances nitrogen retention in green roof plots.

Science.gov (United States)

Johnson, Catherine; Schweinhart, Shelbye; Buffam, Ishi

2016-10-01

Vegetated (green) roofs have become common in many cities and are projected to continue to increase in coverage, but little is known about the ecological properties of these engineered ecosystems. In this study, we tested the biodiversity-ecosystem function hypothesis using commercially available green roof trays as replicated plots with varying levels of plant species richness (0, 1, 3, or 6 common green roof species per plot, using plants with different functional characteristics). We estimated accumulated plant biomass near the peak of the first full growing season (July 2013) and measured runoff volume after nearly every rain event from September 2012 to September 2013 (33 events) and runoff fluxes of inorganic nutrients ammonium, nitrate, and phosphate from a subset of 10 events. We found that (1) total plant biomass increased with increasing species richness, (2) green roof plots were effective at reducing storm runoff, with vegetation increasing water retention more than soil-like substrate alone, but there was no significant effect of plant species identity or richness on runoff volume, (3) green roof substrate was a significant source of phosphate, regardless of presence/absence of plants, and (4) dissolved inorganic nitrogen (DIN = nitrate + ammonium) runoff fluxes were different among plant species and decreased significantly with increasing plant species richness. The variation in N retention was positively related to variation in plant biomass. Notably, the increased biomass and N retention with species richness in this engineered ecosystem are similar to patterns observed in published studies from grasslands and other well-studied ecosystems. We suggest that more diverse plantings on vegetated roofs may enhance the retention capacity for reactive nitrogen. This is of importance for the sustained health of vegetated roof ecosystems, which over time often experience nitrogen limitation, and is also relevant for water quality in receiving waters

Enhancing the biodegradation of oil in sandy sediments with choline: A naturally methylated nitrogen compound

International Nuclear Information System (INIS)

Mortazavi, Behzad; Horel, Agota; Anders, Jennifer S.; Mirjafari, Arsalan; Beazley, Melanie J.; Sobecky, Patricia A.

2013-01-01

We investigated how additions of choline, a naturally occurring methylated nitrogen-containing compound, accelerated hydrocarbon degradation in sandy sediments contaminated with moderately weathered crude oil (4000 mg kg −1 sediment). Addition of lauroylcholine chloride (LCC) and tricholine citrate (TCC) to oil contaminated sediments resulted in 1.6 times higher hydrocarbon degradation rates compared to treatments without added choline derivatives. However, the degradation rate constant for the oil contaminated sediments amended with LCC was similar to that in contaminated sediments amended with inorganic nitrogen, phosphorus, and glucose. Additions of LLC and TCC to sediments containing extensively weathered oil also resulted in enhanced mineralization rates. Cultivation-free 16S rRNA analysis revealed the presence of an extant microbial community with clones closely related to known hydrocarbon degraders from the Gammaproteobacteria, Alphaproteobacteria, and Firmicutes phyla. The results demonstrate that the addition of minimal amounts of organic compounds to oil contaminated sediments enhances the degradation of hydrocarbons. -- Highlights: •Aerobic degradation of weathered crude oil in sandy sediments was determined. •The effect of input of choline on degradation rates was determined. •16S rRNA clone library analyses were used to examine the microbial phylogeny. •The bacterial community was consisted of clones related to hydrocarbon degraders. •Hydrocarbon degradation in sandy sediments was accelerated by addition of choline. -- Choline, a naturally occurring methylated nitrogen-containing compound, accelerated hydrocarbon degradation in sandy sediments by an extant microbial community

Growth and Nitrogen Fixation in Silicon and/or Potassium Fed Chickpeas Grown under Drought and Well Watered Conditions

Directory of Open Access Journals (Sweden)

Fawaz Kurdali

2013-08-01

Full Text Available A pot experiment was conducted to study the effects of silicon (Si and/or potassium (K on plant growth, nitrogen uptake and N2-fixation in water stressed (FC1 and well watered (FC2 chickpea plants using 15N and 13C isotopes. Three fertilizer rates of Si (Si50, Si100 and Si200 and one fertilizer rate of K were used. For most of the growth parameters, it was found that Si either alone or in combination with K was more effective to alleviate water stress than K alone. Increasing soil water level from FC1 to FC2 often had a positive impact on values of almost all studied parameters. The Si100K+ (FC1 and Si50K+ (FC2 treatments gave high enough amounts of N2-fixation, higher dry matter production and greater nitrogen yield. The percent increments of total N2-fixed in the above mentioned treatments were 51 and 47% over their controls, respectively. On the other hand, increasing leave’s dry matter in response to the solely added Si (Si50K- and Si100K- is associated with lower Δ13C under both watering regimes. This may indicate that Si fertilization had a beneficial effect on water use efficiency (WUE. Hence, Δ13C could be an adequate indicator of WUE in response to the exogenous supply of silicon to chickpea plants. Our results highlight that Si is not only involved in amelioration of growth and in maintaining of water status but it can be also considered an important element for the symbiotic performance of chickpea plants. It can be concluded that the synergistic effect of silicon and potassium fertilization with adequate irrigation improves growth and nitrogen fixation in chickpea plants.

Plasma-enhanced growth, composition, and refractive index of silicon oxy-nitride films

DEFF Research Database (Denmark)

Mattsson, Kent Erik

1995-01-01

Secondary ion mass spectrometry and refractive index measurements have been carried out on silicon oxy-nitride produced by plasma-enhanced chemical vapor deposition (PECVD). Nitrous oxide and ammonia were added to a constant flow of 2% silane in nitrogen, to produce oxy-nitride films with atomic...... nitrogen concentrations between 2 and 10 at. %. A simple atomic valence model is found to describe both the measured atomic concentrations and published material compositions for silicon oxy-nitride produced by PECVD. A relation between the Si–N bond concentration and the refractive index is found......-product. A model, that combine the chemical net reaction and the stoichiometric rules, is found to agree with measured deposition rates for given material compositions. Effects of annealing in a nitrogen atmosphere has been investigated for the 400 °C– 1100 °C temperature range. It is observed that PECVD oxy...

Laser-Excited Luminescent Tracers for Planar Concentration Measurements in Gaseous Jets

Science.gov (United States)

Lozano, Antonio

Tracers currently used in planar laser-induced fluorescence concentration measurements are not ideal for some experimental conditions, e.g., non-reacting turbulent gaseous flows at standard temperature and pressure. In this work, a number of chemicals have been evaluated, through consideration of their physical and photophysical properties, for use as luminescent concentration markers in turbulent gaseous flows. Two selected substances, biacetyl and acetone, have been studied in more detail. Acetone PLIF concentration images have been acquired in a non-reacting air jet, and the results have been compared to similar images obtained seeding with biacetyl. Acetone has proven to be a superior tracer when imaging fluorescence emission. Acetone has also been used as a fuel marker in hydrogen and methane diffusion flames. This single -laser technique enables simultaneous recording of the acetone and OH fluorescence emissions, as well as Mie scattering from ambient air dust particles. Acetone-sensitized, collisionally-induced biacetyl phosphorescence has been used to visualize molecular mixing in gaseous flows. Initial attempts to produce quantitative results with this method through simultaneous imaging of acetone fluorescence and collisionally-induced biacetyl emission, are described. Using laser-induced biacetyl phosphorescence imaging, a data set of cross-cut concentration images has been acquired in a nitrogen coflowing jet (Re = 5,000). The images have been statistically analyzed. Very simple models of the instantaneous concentration profile have been compared to the experimental data. Of all the tested models, a paraboloid has resulted to be the best approximation to the instantaneous 2-D profile. Finally, an experiment to study jet mixing in crossflow using acetone PLIF imaging has been designed. The flow facility has been constructed, and preliminary images obtained with a high quantum efficiency, thinned CCD detector have revealed the presence of jet structures

Effect of nitrogen nutrition on growth and nitrate accumulation in lettuce (Lactuca sativa L.), under various conditions of radiation and temperature

International Nuclear Information System (INIS)

Dapoigny, L.; Tourdonnet, S. de; Roger-Estrade, G.; Jeuffroy, M.H.; Fleury, A.

2000-01-01

A better understanding of the effect of environmental factors on growth and nitrate accumulation in plants is necessary to develop cultivation practices, and in particular for providing lettuces with a low nitrate content. This study was conducted to analyse the effect of nitrogen supply on the interception and conversion of the PAR in dry matter, and on the nitrate and water accumulations in fresh tissues of the lettuce, for various conditions of temperature and radiation. The growth, and water and nitrate concentrations of two soilless cultures of lettuce (summer and autumn) were measured for two levels of radiation and two levels of nitrogen supply. RUE ranged from 2.12 to 3.50 gMJ -1 , being higher for a low radiation level and for a high nitrogen supply. There was a positive correlation between the lettuce nitrate and water contents. The slope of this relationship was not affected by environmental conditions, indicating a strong interdependance between nitrate and water accumulation in lettuce. (author) [fr

Increasing plant growth by modulating omega-amidase expression in plants

Science.gov (United States)

Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

2015-06-30

The present disclosure relates to compositions and methods for increasing the leaf-to-root ratio of the signal metabolite 2-oxoglutaramate and related proline molecules in plants by modulating levels of .omega.-amidase to increase nitrogen use efficiency, resulting in enhanced growth, faster growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, increased tolerance to high salt conditions, and increased biomass yields.

Perfect alignment and preferential orientation of nitrogen-vacancy centers during chemical vapor deposition diamond growth on (111) surfaces

International Nuclear Information System (INIS)

Michl, Julia; Zaiser, Sebastian; Jakobi, Ingmar; Waldherr, Gerald; Dolde, Florian; Neumann, Philipp; Wrachtrup, Jörg; Teraji, Tokuyuki; Doherty, Marcus W.; Manson, Neil B.; Isoya, Junichi

2014-01-01

Synthetic diamond production is a key to the development of quantum metrology and quantum information applications of diamond. The major quantum sensor and qubit candidate in diamond is the nitrogen-vacancy (NV) color center. This lattice defect comes in four different crystallographic orientations leading to an intrinsic inhomogeneity among NV centers, which is undesirable in some applications. Here, we report a microwave plasma-assisted chemical vapor deposition diamond growth technique on (111)-oriented substrates, which yields perfect alignment (94% ± 2%) of as-grown NV centers along a single crystallographic direction. In addition, clear evidence is found that the majority (74% ± 4%) of the aligned NV centers were formed by the nitrogen being first included in the (111) growth surface and then followed by the formation of a neighboring vacancy on top. The achieved homogeneity of the grown NV centers will tremendously benefit quantum information and metrology applications

Reference book for the nitrogen industry worker in two volumes, volume 1

Science.gov (United States)

1982-05-01

The first volume presents the physical and chemical properties of gaseous and liquid substances used and obtained at the nitrogen industry enterprises. It describes the different methods for producing and purifying production gases (nitrogen-hydrogen mixture, gas synthesis). It examines the physical and chemical properties of the processes of amonia and methanol synthesis, the industrial plans and the principles for automating them. Certain methods are given for technological calculations, characteristics of the catalysts are presented, and the employed equipment is described. It is designed for engineering-technical workers of enterprises of the nitrogen and other sectors of industry, for specialists working in the scientific research and planning institutes, design offices and other organizations, as well as for teachers of higher educational institutions and students specializing in the field of the technology of inorganic products.

Maize growth in response to Azospirillum brasilense, Rhizobium tropici, molybdenum and nitrogen

Directory of Open Access Journals (Sweden)

Angelita A. C. Picazevicz

Full Text Available ABSTRACT The objective of this research was to evaluate the effect of Azospirillum brasilense, Rhizobium tropici, nitrogen (N and molybdenum (Mo fertilization on maize growth. The experiment was carried out in a greenhouse from October to November 2015, in a completely randomized design, in 2 x 2 x 2 x 5 factorial scheme, with 5 replicates, corresponding to the absence and presence of Azospirillum brasilense, Rhizobium tropici, N (30 kg ha-1 and five Mo doses (0, 7.5, 15.0, 22.5 and 30.0 g ha-1. The analyzed variables were: plant height, basal stem diameter, dry biomass of shoots, roots, total and N accumulated in the shoots. There was double or triple interaction between N fertilization, Azospirillum brasilense and Rhizobium tropici for the evaluated variables. However, isolated and/or combined effect of Mo was not observed. Seed inoculation with Azospirillum brasilense as well as their co-inoculation with Rhizobium tropici in the absence of N fertilization was efficient to increase plant growth. Soil N fertilization at sowing was less efficient in promoting plant growth than when it was combined with seed inoculation with Rhizobium tropici.

Diazotrophic bacteria and nitrogen fertilization on the growth of micropropagated pineapple plantlets during acclimatization

OpenAIRE

Silva,Aurilena de Aviz; Carvalho,Almy Junior Cordeiro de; Freitas,Flávia Paiva de; Pessanha,Patrícia Gomes de Oliveira; Santos,Paulo Cesar dos; Silva,Mírian Peixoto Soares da; Vasconcelos,Tábatha de Souza; Olivares,Fábio Lopes

2016-01-01

ABSTRACT: This study examines the effect of inoculation with diazotrophic bacteria and nitrogen fertilization on the growth of micropropagated pineapple cv. 'Vitória' plantlets during the acclimatization period. The experiment was carried out in a greenhouse in Campos dos Goytacazes, in randomized blocks, using a 2x5x5 factorial scheme, with the factors being two types of inocula (absence or presence of a mixture of diazotrophic bacteria that contained Burkholderia sp. UENF 114111, Burkholder...

Influence of Both Gamma Radiation and Nitrogen Fertilizer Levels on Growth and Productivity of Barley

International Nuclear Information System (INIS)

El-Khawaga, A.A.H.; Farag, I.A.A.; Eliwa, N.E.

2013-01-01

Influences of gamma irradiation doses (zero, 10, 20 and 30 Gy) as well as nitrogen fertilizer levels (zero, 50, 70 and 90 kg N/fad) on growth, yield and yield components of barley cultivar Giza 123 were studied during 2009-2010 and 2010-2011 seasons. The study was conducted in an extension field at Belbees District, Sharkia Governorate, Egypt. Irradiation with the lowest gamma does gave the highest value for each of emergence/m 2 , plant height at heading (cm), flag leaf area at heading (cm 2 ), spike length (cm), number of grains/spike and weight of grains/spike. Nitrogen application significantly increased emergence/m 2 , plant height, flag leaf area (cm 2 ), number of grains/spike, number of spikes/m2 as well as grain, straw and biological yields (kg/fad). Accepted September 2013.

Changes in susceptibility of beech (Fagus sylvatica) seedlings towards Phytophthora citricola under the influence of elevated atmospheric CO{sub 2} and nitrogen fertilization

Energy Technology Data Exchange (ETDEWEB)

Fleischmann, F., E-mail: fleischmann@wzw.tum.d [Phytopathology of Woody Plants, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany); Raidl, S. [Department Biology I and GeoBioCenterLMU, Systematic Mycology, Ludwig Maximilians Universitaet Muenchen, Menzinger Strasse 67, 80638 Muenchen (Germany); Osswald, W.F. [Phytopathology of Woody Plants, Technische Universitaet Muenchen, Am Hochanger 13, 85354 Freising (Germany)

2010-04-15

The growth-differentiation balance hypothesis (GDBH) predicts changes in susceptibility of plants against herbivores with changing resource availability. In the presented study we tested the validity of the GDBH for trees infected with a root pathogen. For this purpose Fagus sylvatica seedlings grown under different atmospheric CO{sub 2}- and soil nitrogen regimes were infected with the root pathogen Phytophthora citricola. High nitrogen supply increased total biomass of beech regardless of the CO{sub 2}-treatment, whereas elevated CO{sub 2} enhanced biomass only in the high nitrogen treatment. The responses of beech under the different growing regimes to the Phytophthora root infection were not in line with the predictions of the GDBH. Enhanced susceptibility of beech against P. citricola was found in seedlings grown under elevated CO{sub 2} and low nitrogen supply. Fifteen months after inoculation these plants were characterized by enhanced water use efficiency, by altered root-shoot ratios, and by enhanced specific root tip densities. - Susceptibility of Fagus sylvatica to the root pathogen Phytophthora citricola increased under elevated CO{sub 2}

Cloned Hemoglobin Genes Enhance Growth Of Cells

Science.gov (United States)

Khosla, Chaitan; Bailey, James E.

1991-01-01

Experiments show that portable deoxyribonucleic acid (DNA) sequences incorporated into host cells make them produce hemoglobins - oxygen-binding proteins essential to function of red blood cells. Method useful in several biotechnological applications. One, enhancement of growth of cells at higher densities. Another, production of hemoglobin to enhance supplies of oxygen in cells, for use in chemical reactions requiring oxygen, as additive to serum to increase transport of oxygen, and for binding and separating oxygen from mixtures of gases.

Hydrogen and Gaseous Fuel Safety and Toxicity

Energy Technology Data Exchange (ETDEWEB)

Lee C. Cadwallader; J. Sephen Herring

2007-06-01

Non-traditional motor fuels are receiving increased attention and use. This paper examines the safety of three alternative gaseous fuels plus gasoline and the advantages and disadvantages of each. The gaseous fuels are hydrogen, methane (natural gas), and propane. Qualitatively, the overall risks of the four fuels should be close. Gasoline is the most toxic. For small leaks, hydrogen has the highest ignition probability and the gaseous fuels have the highest risk of a burning jet or cloud.

Spectroscopic properties of nitrogen doped hydrogenated amorphous carbon films grown by radio frequency plasma-enhanced chemical vapor deposition

International Nuclear Information System (INIS)

Hayashi, Y.; Yu, G.; Rahman, M. M.; Krishna, K. M.; Soga, T.; Jimbo, T.; Umeno, M.

2001-01-01

Nitrogen doped hydrogenated amorphous carbon thin films have been deposited by rf plasma-enhanced chemical vapor deposition using CH 4 as the source of carbon and with different nitrogen flow rates (N 2 /CH 4 gas ratios between 0 and 3), at 300 K. The dependence modifications of the optical and the structural properties on nitrogen incorporation were investigated using different spectroscopic techniques, such as, Raman spectroscopy, Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, ultraviolet-visible (UV-VIS) spectroscopy, electron spin resonance (ESR), photoluminescence (PL) and spectroscopic ellipsometry (SE). Raman spectroscopy and IR absorption reveal an increase in sp 2 -bonded carbon or a change in sp 2 domain size with increasing nitrogen flow rate. It is found that the configuration of nitrogen atoms incorporated into an amorphous carbon network gradually changes from nitrogen atoms surrounded by three (σ bonded) to two (π bonded) neighboring carbons with increasing nitrogen flow rate. Tauc optical gap is reduced from 2.6 to 2.0 eV, and the ESR spin density and the peak-to-peak linewidth increase sharply with increasing nitrogen flow rate. Excellent agreement has been found between the measured SE data and modeled spectra, in which an empirical dielectric function of amorphous materials and a linear void distribution along the thickness have been assumed. The influence of nitrogen on the electronic density of states is explained based on the optical properties measured by UV-VIS and PL including nitrogen lone pair band. [copyright] 2001 American Institute of Physics

Frost formation under different gaseous atmospheres

International Nuclear Information System (INIS)

Fukada, Satoshi; Tsuru, Hisanori; Nishikawa, Masabumi

1995-01-01

Rates of water frost growth in a vessel with a cooled horizontal plate were experimentally determined under reduced pressure atmospheres of hydrogen, helium, methane and nitrogen. The mass deposited on the cooled surface under each of the atmospheres was almost in proportion to time. The Sherwood number under the condition of no mist formation, Sh 0 , in the atmospheres of methane and nitrogen was in good agreement with Catton's equation for natural convection between horizontal parallel plates. Sh 0 in a hydrogen atmosphere was unity, which corresponds to control by molecular diffusion in the stagnant gas. The tendency of the decrease in Sh due to mist formation could be evaluated well by multiplying Sh 0 by a factor ζ CSM . The ζ CSM value was calculated based on the critical supersaturation model as a function of the two interface temperatures and the total pressure. Frost growth rates under each atmosphere were in proportion to [(T S1 -T W1 )t/(1+1/A S1 )] 0.5 . The proportional constant for hydrogen was greater than that for any other tested gas. Agreement and disagreement of the frost effective thermal conductivity with previous models were discussed. (author)

Enhanced photoluminescence from single nitrogen-vacancy defects in nanodiamonds coated with phenol-ionic complexes.

Science.gov (United States)

Bray, Kerem; Previdi, Rodolfo; Gibson, Brant C; Shimoni, Olga; Aharonovich, Igor

2015-03-21

Fluorescent nanodiamonds are attracting major attention in the field of bio-sensing and bio-labeling. In this work we demonstrate a robust approach to achieve an encapsulation of individual nanodiamonds with phenol-ionic complexes that enhance the photoluminescence from single nitrogen vacancy (NV) centers. We show that single NV centres in the coated nanodiamonds also exhibit shorter lifetimes, opening another channel for high resolution sensing. We propose that the nanodiamond encapsulation reduces the non-radiative decay pathways of the NV color centers. Our results provide a versatile and assessable way to enhance photoluminescence from nanodiamond defects that can be used in a variety of sensing and imaging applications.

Method of separating tritium contained in gaseous wastes

International Nuclear Information System (INIS)

Hashimoto, Yasuo; Oozono, Hideaki.

1981-01-01

Purpose: To decrease tritium concentration in gaseous wastes to less than the allowable level by removing tritium in gaseous wastes generated upon combustion of radioactive wastes by using a plurality of heat exchangers. Method: Gaseous wastes at high temperature generated upon combustion of radioactive wastes in an incinerator are removed with radioactive solid substances through filters, cooled down to a temperature below 10 0 C by the passage through first and second heat exchangers and decreased with tritium content to less than the allowable concentration by the gaseous wastes at low temperature from the second heat exhcanger. The gaseous wastes at low temperature are used as the cooling medium for the first heat exchanger. They are heat exchanged at the upstream of the second heat exchanger with the cooling water from the third heat exchanger and cooled at the downstream by the cooling water cooled by the cooling medium. The gaseous wastes at low temperature thus cooled below 10 0 C are heated to about 350 0 C in the first heat exchanger and discharged. (Moriyama, K.)

Nitrogen deficiency in maize. I. Effects on crop growth, development, dry matter partitioning, and kernel set

International Nuclear Information System (INIS)

Uhart, S.A.; Andrade, F.H.

1995-01-01

Variations in N availability affect growth and development of maize (Zea mays L.) and may lead to changes in crop physiological conditions at flowering and in kernel set. The objectives of this study were (i) to establish the effect of N availability on crop development, crop radiation interception, radiation use efficiency, and dry matter partitioning; and (ii) to study the relationship between kernel number and crop growth at flowering and between kernel number and crop N accumulation at flowering. Three experiments with a commercial hybrid (DK636) were carried out under field conditions at the INTA Balcarce Experimental Station, Argentina, without water limitations. The treatments consisted of different radiation levels, obtained by shading, combined with different levels of N availability obtained by the addition of N fertilizer or organic matter to immobilize N. Nitrogen deficiencies delayed both vegetative and reproductive phenological development, slightly reduced leaf emergence rate, and strongly diminished leaf expansion rate and leaf area duration. Nitrogen deficiencies reduced radiation interception as much as radiation use efficiency and their effects on the ear dry mater/total dry matter ratio at harvest were associated with crop growth rate reductions at flowering. Dry matter partitioning to reproductive sinks at flowering and the ear dry matter/total dry matter ratio at harvest were reduced by N shortages. Significant relationships between kernel number and N accumulation rate or crop growth rate at flowering were fitted by linear + plateau functions with thresholds above which kernel number and grain yield did not increase

Enhanced apatite formation on Ti metal heated in PO2-controlled nitrogen atmosphere.

Science.gov (United States)

Hashimoto, Masami; Hayashi, Kazumi; Kitaoka, Satoshi

2013-10-01

The oxynitridation of biomedical titanium metal under a precisely regulated oxygen partial pressure (PO2) of 10(-14)Pa in nitrogen atmosphere at 973 K for 1 h strongly enhanced apatite formation compared with that on Ti heated in air. The factors governing the high apatite-forming ability are discussed from the viewpoint of the surface properties of Ti heated under a PO2 of 10(-14)Pa in nitrogen atmosphere determined from X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and zeta potential measurements. Nitrogen (N)-doped TiO2 (interstitial N) was formed on pure Ti heated under a PO2 of 10(-14)Pa in nitrogen atmosphere at 973 K. The XPS O1s main peak shifted toward a lower binding energy upon heating under a PO2 of 10(-14)Pa. This shift may be due to the formation of oxygen vacancies. This Ti surface had a positive zeta potential of approximately 20 mV. According to time-of-flight secondary ion mass spectroscopy results, PO4(3-) ions were predominantly adsorbed on Ti soaked in simulated body fluid (SBF) after heat treatment, followed by calcium ions. It was concluded that the apatite formation kinetics can be described using the Avrami-Erofeev equation with an Avrami index of n=2, which implies the instantaneous nucleation of apatite on the surface of Ti soaked in SBF after heat treatment at 973 K under a PO2 of 10(-14)Pa. Copyright © 2013 Elsevier B.V. All rights reserved.

Response of maize varieties to nitrogen application for leaf area profile, crop growth, yield and yield components

International Nuclear Information System (INIS)

Akmal, M.; Hameed-urRehman; Farhatullah; Asim, M.; Akbar, H.

2010-01-01

An experiment was conducted at NWFP Agricultural University, Peshawar, to study maize varieties and Nitrogen (N) rates for growth, yield and yield components. Three varieties (Azam, Jalal and Sarhad white) and three N rates (90, 120, 150, kg N ha/sup -1/) were compared. Experiment was conducted in a Randomized Complete Block design; split plot arrangement with 4 replications. Uniform and recommended cultural practices were applied during the crop growth. The results revealed that maize variety 'Jalal' performed relatively better crop growth rate (CGR) and leaf area profile (LAP) at nodal position one to six as compared to the other two varieties (Sarhad white and Azam). This resulted higher radiation use efficiency by the crop canopy at vegetative stage of development and hence contributed higher assimilates towards biomass production. Heavier grains in number and weight were due to higher LAP and taller plants of Jalal which yielded higher in the climate. Nitrogen applications have shown that maize seed yield increase in quadratic fashion with increased N to a plateau level. Considering soil fertility status and cropping system, the 150 kg ha/sup -1/ N application to maize variety Jalal in Peshawar is required for maximum biological and seed production. (author)

Ectomycorrhizal fungi enhance nitrogen and phosphorus nutrition of Nothofagus dombeyi under drought conditions by regulating assimilative enzyme activities.

Science.gov (United States)

Alvarez, Maricel; Huygens, Dries; Olivares, Erick; Saavedra, Isabel; Alberdi, Miren; Valenzuela, Eduardo

2009-08-01

Drought stress conditions (DC) reduce plant growth and nutrition, restraining the sustainable reestablishment of Nothofagus dombeyi in temperate south Chilean forest ecosystems. Ectomycorrhizal symbioses have been documented to enhance plant nitrogen (N) and phosphorus (P) uptake under drought, but the regulation of involved assimilative enzymes remains unclear. We studied 1-year-old N. dombeyi (Mirb.) Oerst. plants in association with the ectomycorrhizal fungi Pisolithus tinctorius (Pers.) Coker & Couch. and Descolea antartica Sing. In greenhouse experiments, shoot and root dry weights, mycorrhizal colonization, foliar N and P concentrations, and root enzyme activities [glutamate synthase (glutamine oxoglutarate aminotransferase (GOGAT), EC 1.4.1.13-14), glutamine synthetase (GS, EC 6.3.1.2), glutamate dehydrogenase (GDH, EC 1.4.1.2-4), nitrate reductase (NR, EC 1.6.6.1), and acid phosphomonoesterase (PME, EC 3.1.3.1-2)] were determined as a function of soil-water content. Inoculation of N. dombeyi with P. tinctorius and D. antartica significantly stimulated plant growth and increased plant foliar N and P concentrations, especially under DC. Ectomycorrhizal inoculation increased the activity of all studied enzymes relative to non-mycorrhizal plants under drought. We speculate that GDH is a key enzyme involved in the enhancement of ectomycorrhizal carbon (C) availability by fuelling the tricarboxylic acid (TCA) cycle under conditions of drought-induced carbon deficit. All studied assimilative enzymes of the ectomycorrhizal associations, involved in C, N, and P transfers, are closely interlinked and interdependent. The up-regulation of assimilative enzyme activities by ectomycorrhizal fungal root colonizers acts as a functional mechanism to increase seedling endurance to drought. We insist upon incorporating ectomycorrhizal inoculation in existing Chilean afforestation programs.

Effects of water salinity and nitrogen fertilization on the growth and yield of ‘BRS Gabriela’ castor beans

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João Batista dos Santos

2016-10-01

Full Text Available The castor bean has attracted the attention of many farmers as an alternative crop for the National Program of Biofuel and its extensive use in the ricinochemical industry. The crop requires large planting areas to meet the demands of the fuel market. The aim of the present study was to evaluate the effects of irrigation water salinity and nitrogen fertilization on the growth and production of castor beans, ‘BRS Gabriela’, in a protected environment. The present study was conducted at the Center of Technology and Natural Resources of the Federal University of Campina Grande. The experimental design was completely randomized in a 5 × 4 factorial with three replications and one plant per plot. The treatments consisted of irrigation water with five electrical conductivity (ECw levels of 0.7, 1.7, 2.7, 3.7, and 4.7 dS m-1 associated with four nitrogen levels of 60, 80, 100, and 120 mg of N kg-1 of soil. The interaction between water salinity and nitrogen rates did not exert significant effects on the variables studied. Increased salinity of irrigation water affected the growth in height and stem diameter of castor beans in all periods, and leaf area from 90 days after sowing. Increased nitrogen levels had a positive effect on leaf area at 60, 90, 120, and 150 days after sowing. The total mass of seeds, one hundred seed mass, yield, and number of fruits per plant decreased with the increase in water salinity, and the total mass of seeds was the most affected variable.

Enhanced photoluminescence from single nitrogen-vacancy defects in nanodiamonds coated with metal-phenolic networks

OpenAIRE

Bray, Kerem; Previdi, Rodolfo; Gibson, Brant C.; Shimoni, Olga; Aharonovich, Igor

2015-01-01

Fluorescent nanodiamonds are attracting major attention in the field of bio-sensing and biolabeling. In this work we demonstrate a robust approach to surface functionalize individual nanodiamonds with metal-phenolic networks that enhance the photoluminescence from single nitrogen vacancy (NV) centers. We show that single NV centres in the coated nanodiamonds also exhibit shorter lifetimes, opening another channel for high resolution sensing. We propose that the nanodiamond encapsulation suppr...

Combined metals and EDTA control: An integrated and scalable lipid enhancement strategy to alleviate biomass constraints in microalgae under nitrogen limited conditions

International Nuclear Information System (INIS)

Singh, Poonam; Guldhe, Abhishek; Kumari, Sheena; Rawat, Ismail; Bux, Faizal

2016-01-01

Highlights: • A. obliquus showed highest lipid productivity amongst all seven microalgal strains. • Combined metals stress eased the constraint of low biomass under limited nitrogen. • Combined metals stress enhanced the overall lipid productivity (1.99 fold). • EDTA addition further improved the lipid productivity (2.18 fold). • This strategy showed 2.08 fold increase in lipid productivity at 3000 L cultivation. - Abstract: The commercial realization of microalgal biodiesel production necessitates substantial impulsion towards development of strategies to improve lipid yields upstream. Nitrogen stress is the most widely used lipid enhancement strategy; yet, it is associated with compromised biomass productivity. In this novel approach, combined effect of metals and EDTA on lipid productivity of Acutodesmus obliquus was investigated under nitrogen limited conditions. The effect of metal concentrations, individually and in combination, on microalgal lipids and biomass production is a scarcely exploited area. Combined metal stress alleviates the constraint of low biomass production under nitrogen limitation and improved the overall lipid productivity. Highest lipid productivity of 73.23 mg L"−"1 d"−"1 was achieved with a combination of iron 9 mg L"−"1, magnesium 100 mg L"−"1 and calcium 27 mg L"−"1 at limited nitrogen (750 mg L"−"1). This was 1.72 fold higher than nitrogen stress alone and 1.99 fold higher than BG11 medium. Iron was found to be most significantly influencing metal followed by magnesium in response surface methodology data analysis. The enhanced photosynthetic performance and chlorophyll content further confirmed the significant impact of iron and magnesium on the microalgal biomass. The addition of EDTA to the optimised metal combination further improved the lipid productivity to 80.23 mg L"−"1 d"−"1 (2.18 fold). At 3000 L open cultivation pond this strategy has resulted in an increase of 2.08 fold in lipid productivity

Interactive Effects of CO2 Concentration and Water Regime on Stable Isotope Signatures, Nitrogen Assimilation and Growth in Sweet Pepper

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María D. Serret

2018-01-01

Full Text Available Sweet pepper is among the most widely cultivated horticultural crops in the Mediterranean basin, being frequently grown hydroponically under cover in combination with CO2 fertilization and water conditions ranging from optimal to suboptimal. The aim of this study is to develop a simple model, based on the analysis of plant stable isotopes in their natural abundance, gas exchange traits and N concentration, to assess sweet pepper growth. Plants were grown in a growth chamber for near 6 weeks. Two [CO2] (400 and 800 μmol mol−1, three water regimes (control and mild and moderate water stress and four genotypes were assayed. For each combination of genotype, [CO2] and water regime five plants were evaluated. Water stress applied caused significant decreases in water potential, net assimilation, stomatal conductance, intercellular to atmospheric [CO2], and significant increases in water use efficiency, leaf chlorophyll content and carbon isotope composition, while the relative water content, the osmotic potential and the content of anthocyanins did change not under stress compared to control conditions support this statement. Nevertheless, water regime affects plant growth via nitrogen assimilation, which is associated with the transpiration stream, particularly at high [CO2], while the lower N concentration caused by rising [CO2] is not associated with stomatal closure. The stable isotope composition of carbon, oxygen, and nitrogen (δ13C, δ18O, and δ15N in plant matter are affected not only by water regime but also by rising [CO2]. Thus, δ18O increased probably as response to decreases in transpiration, while the increase in δ15N may reflect not only a lower stomatal conductance but a higher nitrogen demand in leaves or shifts in nitrogen metabolism associated with decreases in photorespiration. The way that δ13C explains differences in plant growth across water regimes within a given [CO2], seems to be mediated through its direct

[Effects of controlled release blend bulk urea on soil nitrogen and soil enzyme activity in wheat and rice fields].

Science.gov (United States)

Zhang, Jing Sheng; Wang, Chang Quan; Li, Bing; Liang, Jing Yue; He, Jie; Xiang, Hao; Yin, Bin; Luo, Jing

2017-06-18

A field experiment was conducted to investigate the effect of controlled-release fertilizer (CRF) combined with urea (UR) on the soil fertility and environment in wheat-rice rotation system. Changes in four forms of nitrogen (total nitrogen, ammonium nitrogen, nitrate nitrogen, and microbial biomass nitrogen) and in activities of three soil enzymes participating in nitrogen transformation (urease, protease, and nitrate reductase) were measured in seven fertilization treatments (no fertilization, routine fertilization, 10%CRF+90%UR, 20%CRF+80%UR, 40%CRF+60%UR, 80%CRF+20%UR, and 100%CRF). The results showed that soil total nitrogen was stable in the whole growth period of wheat and rice. There was no significant difference among the treatments of over 20% CRF in soil total nitrogen content of wheat and rice. The soil inorganic nitrogen content was increased dramatically in treatments of 40% or above CRF during the mid-late growing stages of wheat and rice. With the advance of the growth period, conventional fertilization significantly decreased soil microbial biomass nitrogen, but the treatments of 40% and above CRF increased the soil microbial biomass nitrogen significantly. The soil enzyme activities were increased with over 40% of CRF in the mid-late growing stage of wheat and rice. By increasing the CRF ratio, the soil protease activity and nitrate reductase activity were improved gradually, and peaked in 100% CRF. The treatments of above 20% CRF could decrease the urease activity in tillering stage of rice and delay the peak of ammonium nitrogen, which would benefit nitrogen loss reduction. The treatments of 40% and above CRF were beneficial to improving soil nitrogen supply and enhancing soil urease and protease activities, which could promote the effectiveness of nitrogen during the later growth stages of wheat and rice. The 100% CRF treatment improved the nitrate reductase activity significantly during the later stage of wheat and rice. Compared with the

Effect of synchronizing the rate of degradation of dietary energy and nitrogen release on growth performance in Brahman cattle

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Virote Pattarajinda

2006-01-01

Full Text Available The objective of this research was to determine the effect of synchronizing the rate of degradation of dietary energy and nitrogen release on growth performance in Brahman beef cattle. Fifteen Brahman cattle, 1.5 years old, with an average initial body weight of 184.8±11.1 kg were assigned to one of three treatments according to a randomized complete block design. Dietary treatments contained 3 levels of synchrony index (0.39, 0.56 and 0.74 that were derived from laboratory chemical composition analysis and degradation kinetics using nylon bag technique. Diets were fed at the rate of 2.5% BW by separate concentrate and roughage. Average daily gain increased linearly (P<0.05 with increase levels of synchrony index in the diets. The digestibility of dry matter, organic matter and neutral detergent fiber increased linearly (P<0.01. The digestibility of acid detergent fiber increased linearly (P<0.05. Ruminal total volatile fatty acids concentration increased linearly (P<0.05 at 6 h post feeding. Higher concentration and fluctuation of ruminal ammonia nitrogen and blood urea nitrogen were observed in animals that received lower synchrony index in their diets. Rumen microbial population tended to increase with diets having higher levels of synchrony index. The results indicated that synchronized rate of dietary energy and nitrogen degradation improved ruminal fermentation and digestibility, thus this increased the growth rate in Brahman cattle fed with ricestraw- based diets.

Nitrogen stimulates phenological traits, growth and growing degree days of maize

International Nuclear Information System (INIS)

Hammad, H.M.; Ahmad, A.; Farhad, W.; Abbas, F.

2013-01-01

Field experiments were conducted during 2009 and 2010 to evaluate the effects of nitrogen (N) application timings and rates on phenology of autumn sown maize under semi-arid climatic conditions of Faisalabad, Pakistan. Plant development, growth and yield components were optimized by the N application in three splits; 1/3rd N at V2, 1/3rd N at V16 and 1/3rd N at R1 stages at the rate of 250 kg ha-1. At this rate, the crop achieved more calendar days and thermal time in each growth stage. The treatments T2 (1/3rd N at V2 stage, 1/3rd N at V16 stage and 1/3rd N at R1 stage) and N4 (250 kg N ha-1) accumulated the maximum days to silking and maturity (51 and 102 days, respectively), which resulted in the maximum crop growth rate and grain yield (8.38 t ha/sup -1/). The highest net benefit and marginal rate of return ($1857 and 22%, respectively) were achieved by N/sub 4/ treatment. Therefore, 250 kg N ha-1 with three above mentioned splits of N application may produce optimum grain yield of maize under semi-arid environmental and agricultural conditions similar to those of the reported experiments. (author)

Effect of Different Nitrogen Levels on Phenology, Growth Indices and Yield of two Lentil Cultivars under Rainfed Conditions in Mashhad

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M Bannayan Aval

2018-02-01

Full Text Available Introduction Lentil (Lens Culinarris Medik. is an important pulse crop in Iran and is usually grown in rainfed areas. The average lentil yield in Iran is 1195 and 476 Kg.ha-1 in irrigated and rainfed farms, respectively. Low productivity occurs due to different factors. One of these factors is poor agronomic management practices that applied by the farmers, e.g. Limitation or inappropriate fertilizer distribution. Plant development occurs in a number of consecutive phases. These phases can be affected by temperature, moisture, photoperiod, cultivar and other factors. The amount of available nitrogen affects the distribution of assimilates between vegetative and reproductive organs and phenological stages of growth. Therefore, analysis of growth indices and its effective factors can be used as a suitable tool in evaluating the yield. The aim of this study was to evaluate the effect of different nitrogen levels on phenology and growth indices of two lentil cultivars in rainfed conditions of Mashhad. Materials and Methods The experiment was conducted as split plot layout based on randomized complete blocks design with three replications at the Agricultural Research Station, Ferdowsi University of Mashhad, during growth season 2016. Nitrogen fertilizer as urea (in three levels i.e. 0, 40 and 80 kg.ha-1 and cultivar (in two levels i.e. Birjand and Robat were in main plots and sub plots, respectively. To determine the leaf area and dry matter, sampling was done every two weeks during the growing season. Phenological stages timing for each plot were determined based on 50% of emergence, 50% of flowering, 50% of maturity. Final yield was estimated from three square meter from each plot. Data were analyzed with the SAS software; the means were compared with Duncan's multiple range tests at the 5% level of probability. The graphs were prepared by SigmaPlot software. Results and Discussion The results showed that the effect of urea fertilizer was

Arbuscular mycorrhiza improve growth, nitrogen uptake, and nitrogen use efficiency in wheat grown under elevated CO2

DEFF Research Database (Denmark)

Zhu, Xiancan; Song, Fengbin; Liu, Shengqun

2016-01-01

Effects of the arbuscular mycorrhizal (AM) fungus Rhizophagus irregularis on plant growth, carbon (C) and nitrogen (N) accumulation, and partitioning was investigated in Triticum aestivum L. plants grown under elevated CO2 in a pot experiment. Wheat plants inoculated or not inoculated with the AM...... and higher plant biomass than the non-AM plants. CO2 elevation did not affect C and N partitioning in plant organs, while AM symbiosis increased C and N allocation into the roots. In addition, plant C and N accumulation, (15)N recovery rate, and N use efficiency (NUE) were significantly higher in AM plants...... than in non-AM controls under CO2 enrichment. It is concluded that AM symbiosis favors C and N partitioning in roots, increases C accumulation and N uptake, and leads to greater NUE in wheat plants grown at elevated CO2....

Rapid cycling of reactive nitrogen in the marine boundary layer.

Science.gov (United States)

Ye, Chunxiang; Zhou, Xianliang; Pu, Dennis; Stutz, Jochen; Festa, James; Spolaor, Max; Tsai, Catalina; Cantrell, Christopher; Mauldin, Roy L; Campos, Teresa; Weinheimer, Andrew; Hornbrook, Rebecca S; Apel, Eric C; Guenther, Alex; Kaser, Lisa; Yuan, Bin; Karl, Thomas; Haggerty, Julie; Hall, Samuel; Ullmann, Kirk; Smith, James N; Ortega, John; Knote, Christoph

2016-04-28

Nitrogen oxides are essential for the formation of secondary atmospheric aerosols and of atmospheric oxidants such as ozone and the hydroxyl radical, which controls the self-cleansing capacity of the atmosphere. Nitric acid, a major oxidation product of nitrogen oxides, has traditionally been considered to be a permanent sink of nitrogen oxides. However, model studies predict higher ratios of nitric acid to nitrogen oxides in the troposphere than are observed. A 'renoxification' process that recycles nitric acid into nitrogen oxides has been proposed to reconcile observations with model studies, but the mechanisms responsible for this process remain uncertain. Here we present data from an aircraft measurement campaign over the North Atlantic Ocean and find evidence for rapid recycling of nitric acid to nitrous acid and nitrogen oxides in the clean marine boundary layer via particulate nitrate photolysis. Laboratory experiments further demonstrate the photolysis of particulate nitrate collected on filters at a rate more than two orders of magnitude greater than that of gaseous nitric acid, with nitrous acid as the main product. Box model calculations based on the Master Chemical Mechanism suggest that particulate nitrate photolysis mainly sustains the observed levels of nitrous acid and nitrogen oxides at midday under typical marine boundary layer conditions. Given that oceans account for more than 70 per cent of Earth's surface, we propose that particulate nitrate photolysis could be a substantial tropospheric nitrogen oxide source. Recycling of nitrogen oxides in remote oceanic regions with minimal direct nitrogen oxide emissions could increase the formation of tropospheric oxidants and secondary atmospheric aerosols on a global scale.

Gaseous fuel reactors for power systems

Science.gov (United States)

Kendall, J. S.; Rodgers, R. J.

1977-01-01

Gaseous-fuel nuclear reactors have significant advantages as energy sources for closed-cycle power systems. The advantages arise from the removal of temperature limits associated with conventional reactor fuel elements, the wide variety of methods of extracting energy from fissioning gases, and inherent low fissile and fission product in-core inventory due to continuous fuel reprocessing. Example power cycles and their general performance characteristics are discussed. Efficiencies of gaseous fuel reactor systems are shown to be high with resulting minimal environmental effects. A technical overview of the NASA-funded research program in gaseous fuel reactors is described and results of recent tests of uranium hexafluoride (UF6)-fueled critical assemblies are presented.

Growth response of Douglas-fir seedlings to nitrogen fertilization: importance of Rubisco activation state and respiration rates.

Science.gov (United States)

Daniel K. Manter; Kathleen L. Kavanagh; Cathy L. Rose

2005-01-01

High foliar nitrogen concentration ([N]) is associated with high rates of photosynthesis and thus high tree productivity; however, at excessive [N], tree productivity is reduced. Reports of excessive [N] in the Douglas-fir forests of the Oregon Coast Range prompted this investigation of growth and needle physiological responses to increasing foliar N concentrations in...

Atmospheric nitrogen dioxide at ambient levels stimulates growth and development of horticultural plants

International Nuclear Information System (INIS)

Adam, S.E.H.; Shigeto, J.; Sakamoto, A.; Takahashi, M.; Morikawa, H.

2008-01-01

Studies have demonstrated that ambient levels of atmospheric nitrogen dioxide (NO 2 ) can cause Nicotiana plumbaginifolia to double its biomass as well as its cell contents. This paper examined the influence of NO 2 on lettuce, sunflower, cucumber, and pumpkin plants. Plants were grown in environments supplemented with stable isotope-labelled NO 2 for approximately 6 weeks and irrigated with nitrates. Measured growth parameters included leaf number, internode number, stem length, number of flower buds, and root length. Results of the study demonstrated that the addition of NO 2 doubled the aboveground and belowground biomass of sunflowers, while only the aboveground biomass of pumpkin, cucumbers, and lettuces was doubled. Levels of carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were also doubled in the lettuce samples. A mass spectrometry analysis showed that only a small percentage of total plant N was derived from NO 2 . It was concluded that exogenous NO 2 additions function as a signal rather than as a significant nutrient source in horticultural plants. 22 refs., 2 tabs., 1 fig

Effect of non-protein nitrogen and fodder legumes on the intake, digestibility and growth parameters of buffaloes

International Nuclear Information System (INIS)

Premaratne, S.

1990-01-01

Two in vivo digestibility studies and three nylon bag studies were conducted using four rumen fistulated male buffaloes to investigate the role of supplements of tree legumes and non-protein nitrogen on the feed intake, rumen function and growth of buffaloes given a basal diet of rice straw. Straw dry matter (DM) intake and digestibility were increased by urea treatment compared with urea supplementation. Inclusion of legume tree leaves in the diet increased the in vivo DM digestibility of both untreated and treated straw, but the increment was much higher for untreated straw. A supplementation of legumes also increased the in vivo nitrogen (N) digestibility of the diet of buffaloes. A trend towards an increase in straw intake with legume supplementation was also observed. Of the tree fodder legumes tested, Erythrina lithosperma had the highest potential for providing protein. Inclusion of legumes in the diet increased the DM and N degradation rates of feedstuff. In a growth trial of grazing female buffalo calves, the inclusion of fodder legumes increased the weight gain when compared with grazing alone. (author). 6 refs, 5 tabs

Rate and time of nitrogen fertilizer application on the growth, nitrogen remobilization and yield of soyabean (Glycine max(L) Merrill)

International Nuclear Information System (INIS)

Bebeley, J. F.; Sarkodie-Addo; Duku, S.

2015-01-01

Two field experiments were conducted in 2012 at the plantation Crop section of the Department of Crop and Soil Sciences, Kwame Nkrumah University of Science and Technology, to investigate the effect N availability on nodulation, nitrogen fixation, N remobilization and grain yield of soybean. The design used in both studies was a 3 x 4 factorial arranged in randomized complete block design. Each treatment was replicated three times. The factors studied were rate and time of N fertilizer application. The N rate were 0, 20, 40 and 60kg N/ha and the time of application were early vegetative and early flowering phases. Anidaso, an improved soybean variety of 110 days maturity was used. Following land preparation, seeds were planted at the beginning of the rains at a spacing of 50 x 5cm. All required cultural practices were observed. Data collected were nodule number per plant and nodule dry weight, number of pods per plant, number of seeds per pod, 100 seeds weight, total nitrogen fixed, harvest index, grain yield and remobilized N. The total nitrogen difference method was used in determining the amount of N 2 fixed by the soybean and the micro kjeldahl method was used in determining the total plant N. The results indicated that nodulation was not significantly (p>0.05) affected by N rate and time of N application. However Nitrogen fixation was significantly (p<0.05 in affected time of N application in the minor season. Harvest index was significantly affected time of N application in the major season. Grain yield was also significantly affected by time of N application in both seasons. The results indicate that if farmers would apply N fertilizer to soybean at the vegetative growth phase, there would be increase in yield. The study also demonstrate that N remobilization occurs in soybean during grain filling although rate and time of application used did not significantly (p>0.05) affect N remobilization. (au)

PLANT-MICROBIAL INTERACTIONS IN THE RHIZOSPHERE – STRATEGIES FOR PLANT GROWTH-PROMOTION

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Marius Stefan

2012-03-01

Full Text Available Plant growth-promoting rhizobacteria (PGPR are a group of bacteria that can actively colonize plant rootsand enhance plant growth using different mechanisms: production of plant growth regulators like indoleacetic acid,gibberellic acid, cytokinins and ethylene(Zahir et al., 2003, providing the host plant with fixed nitrogen, solubilizationof soil phosphorus, enhance Fe uptake, biocontrol, reducing the concentration of heavy metals. PGPR are perfectcandidates to be used as biofertilizers – eco-friendly alternative to common applied chemical fertilizer in today’sagriculture. The most important benefit of PGPR usage is related to the reduction of environmental pollution in conditionof increasing crop yield. This review presents the main mechanisms involved in PGPR promotion of plant growth.

Comparison of nitrogen removal rates and nitrous oxide production from enriched anaerobic ammonium oxidizing bacteria in suspended and attached growth reactors.

Science.gov (United States)

Panwivia, Supaporn; Sirvithayapakorn, Sanya; Wantawin, Chalermraj; Noophan, Pongsak Lek; Munakata-Marr, Junko

2014-01-01

Attached growth-systems for the anaerobic ammonium oxidation (anammox) process have been postulated for implementation in the field. However, information about the anammox process in attached growth-systems is limited. This study compared nitrogen removal rates and nitrous oxide (N2O) production of enriched anammox cultures in both suspended and attached growth sequencing batch reactors (SBRs). Suspended growth reactors (SBR-S) and attached growth reactors using polystyrene sponge as a medium (SBR-A) were used in these experiments. After inoculation with an enriched anammox culture, significant nitrogen removals of ammonium (NH4 (+)) and nitrite (NO2 (-)) were observed under NH4 (+):NO2 (-) ratios ranging from 1:1 to 1:2 in both types of SBRs. The specific rates of total nitrogen removal in SBR-S and SBR-A were 0.52 mg N/mg VSS-d and 0.44 mg N/mg VSS-d, respectively, at an NH4 (+):NO2 (-) ratio of 1:2. N2O production by the enriched anammox culture in both SBR-S and SBR-A was significantly higher at NH4 (+):NO2 (-) ratio of 1:2 than at NH4 (+):NO2 (-) ratios of 1:1 and 1:1.32. In addition, N2O production was higher at a pH of 6.8 than at pH 7.3, 7.8, and 8.3 in both SBR-S and SBR-A. The results of this investigation demonstrate that the anammox process may avoid N2O emission by maintaining an NH4 (+):NO2 (-) ratio of less than 1:2 and pH higher than 6.8.

Nitrogen and azolla response on growth of rice plant of Mitra-I variety with SRI method

International Nuclear Information System (INIS)

Nurmayulis; Putra Utama; Dewi Firnia; Hasnan Yani; Ania Citraresmini

2011-01-01

The research was conducted in Cisadap, Bunter Village, District of Sukadana, Ciamis Regency, West Java Province from January to May 2011. This study was carried out to know the response of growth of rice plant which was fertilized by nitrogen fertilizer and Azolla michrophylla using the system of rice intensification. This research used five dozes of nitrogen fertilizer (0 %, 25 %, 50 %, 75 %, 100 %) from N 92 kg ha -1 as a recommended nitrogen fertilizer (urea 200 kg ha -1 ), and also 1,13 ton ha -1 Azolla michrophylla. The result obtained from this research showed that the application of N fertilizer at 50 % of the recommend dose (100 kg ha -1 ) with adding Azolla at a rate of 1.13 t ha -1 gave good result in the terms of plant height at 2-6 weeks after planting and number of tillers at 2-7 weeks after planting. Interaction of the 50 % N fertilizer from the recommended dose planting 1,13 t ha -1 give the highest dry weight of Azolla of plants at seven weeks after planting. (author)

Structural sensitivity of cyclic crack resistance of rotor steel in gaseous hydrogen

International Nuclear Information System (INIS)

Romaniv, O.N.; Nikiforchin, G.N.; Kozak, L.Yu.

1984-01-01

Comparative evaluation of cyclic crack resistance of hardened rotor set steel 35KhN3MFA in different cstructural states during tesis in agea geseous hydrogen, in the air and in vacuum, has been mde made. It is shown, that structural sensitivity of near-threshold crack resistance of the studied rotor steel in gaseous hydrogen is to a high extent determined by the closing and morphology of fatigue crack. The decrease in crack closing (CC) observed during tests in hydrogen in low-strenght and crack branching in high-strength steels results in the fact, that in contrast to well-known notions on a higher sensitivity to hydrogen embrittlement of high-strenght alloys the negative effect of hydrogen on the near-threshold cyclic crack resistance is manifested only in steel in low-strenght state. The considered regularities in crack growth in low-alloyed steel under the effect of gaseous hydrogen are just only for high-frequency loading. In all probability in the case of fatigue crack growth (GCG) at low frequencies of loading not only the medium activity, but also the role o, closing and crack geometty in the kinetics of fatigue fracture, the clarifying of which requires further studieds, will change

Limitations to CO2-induced growth enhancement in pot studies.

Science.gov (United States)

McConnaughay, K D M; Berntson, G M; Bazzaz, F A

1993-07-01

Recently, it has been suggested that small pots may reduce or eliminate plant responses to enriched CO 2 atmospheres due to root restriction. While smaller pot volumes provide less physical space available for root growth, they also provide less nutrients. Reduced nutrient availability alone may reduce growth enhancement under elevated CO 2 . To investigate the relative importance of limited physical rooting space separate from and in conjunction with soil nutrients, we grew plants at ambient and double-ambient CO 2 levels in growth containers of varied volume, shape, nutrient concentration, and total nutrient content. Two species (Abutilon theophrasti, a C 3 dicot with a deep tap root andSetaria faberii, a C 4 monocot with a shallow diffuse root system) were selected for their contrasting physiology and root architecture. Shoot demography was determined weekly and biomass was determined after eight and ten weeks of growth. Increasing total nutrients, either by increasing nutrient concentration or by increasing pot size, increased plant growth. Further, increasing pot size while maintaining equal total nutrients per pot resulted in increased total biomass for both species. CO 2 -induced growth and reproductive yield enhancements were greatest in pots with high nutrient concentrations, regardless of total nutrient content or pot size, and were also mediated by the shape of the pot. CO 2 -induced growth and reproductive yield enhancements were unaffected by pot size (growth) or were greater in small pots (reproductive yield), regardless of total nutrient content, contrary to predictions based on earlier studies. These results suggest that several aspects of growth conditions within pots may influence the CO 2 responses of plants; pot size, pot shape, the concentration and total amount of nutrient additions to pots may lead to over-or underestimates of the CO 2 responses of real-world plants.

Gaseous air pollution and emergency hospital visits for hypertension in Beijing, China: a time-stratified case-crossover study

Directory of Open Access Journals (Sweden)

Zhang Yanshen

2010-10-01

Full Text Available Abstract Background A number of epidemiological studies have been conducted to research the adverse effects of air pollution on mortality and morbidity. Hypertension is the most important risk factor for cardiovascular mortality. However, few previous studies have examined the relationship between gaseous air pollution and morbidity for hypertension. Methods Daily data on emergency hospital visits (EHVs for hypertension were collected from the Peking University Third Hospital. Daily data on gaseous air pollutants (sulfur dioxide (SO2 and nitrogen dioxide (NO2 and particulate matter less than 10 μm in aerodynamic diameter (PM10 were collected from the Beijing Municipal Environmental Monitoring Center. A time-stratified case-crossover design was conducted to evaluate the relationship between urban gaseous air pollution and EHVs for hypertension. Temperature and relative humidity were controlled for. Results In the single air pollutant models, a 10 μg/m3 increase in SO2 and NO2 were significantly associated with EHVs for hypertension. The odds ratios (ORs were 1.037 (95% confidence interval (CI: 1.004-1.071 for SO2 at lag 0 day, and 1.101 (95% CI: 1.038-1.168 for NO2 at lag 3 day. After controlling for PM10, the ORs associated with SO2 and NO2 were 1.025 (95% CI: 0.987-1.065 and 1.114 (95% CI: 1.037-1.195, respectively. Conclusion Elevated urban gaseous air pollution was associated with increased EHVs for hypertension in Beijing, China.

[Nitrogen cycling in rice-duck mutual ecosystem during double cropping rice growth season].

Science.gov (United States)

Zhang, Fan; Chen, Yuan-Quan; Sui, Peng; Gao, Wang-Sheng

2012-01-01

Raising duck in paddy rice field is an evolution of Chinese traditional agriculture. In May-October 2010, a field experiment was conducted in a double cropping rice region of Hunan Province, South-central China to study the nitrogen (N) cycling in rice-duck mutual ecosystem during early rice and late rice growth periods, taking a conventional paddy rice field as the control. Input-output analysis method was adopted. The N output in the early rice-duck mutual ecosystem was 239.5 kg x hm(-2), in which, 12.77 kg x hm(-2) were from ducks, and the N output in the late rice-duck mutual ecosystem was 338.7 kg x hm(-2), in which, 23.35 kg x hm(-2) were from ducks. At the present N input level, there existed soil N deficit during the growth seasons of both early rice and late rice. The N input from duck sub-system was mainly from the feed N, and the cycling rate of the duck feces N recycled within the system was 2.5% during early rice growth season and 3.5% during late rice growth season. After late rice harvested, the soil N sequestration was 178.6 kg x hm(-2).

The nitrogen cycle.

Science.gov (United States)

Stein, Lisa Y; Klotz, Martin G

2016-02-08

Nitrogen is the fourth most abundant element in cellular biomass, and it comprises the majority of Earth's atmosphere. The interchange between inert dinitrogen gas (N2) in the extant atmosphere and 'reactive nitrogen' (those nitrogen compounds that support, or are products of, cellular metabolism and growth) is entirely controlled by microbial activities. This was not the case, however, in the primordial atmosphere, when abiotic reactions likely played a significant role in the inter-transformation of nitrogen oxides. Although such abiotic reactions are still important, the extant nitrogen cycle is driven by reductive fixation of dinitrogen and an enzyme inventory that facilitates dinitrogen-producing reactions. Prior to the advent of the Haber-Bosch process (the industrial fixation of N2 into ammonia, NH3) in 1909, nearly all of the reactive nitrogen in the biosphere was generated and recycled by microorganisms. Although the Haber-Bosch process more than quadrupled the productivity of agricultural crops, chemical fertilizers and other anthropogenic sources of fixed nitrogen now far exceed natural contributions, leading to unprecedented environmental degradation. Copyright © 2016 Elsevier Ltd. All rights reserved.