WorldWideScience

Sample records for biodegradable mulch sheet

  1. Utilization of a Biodegradable Mulch Sheet Produced from Poly(Lactic Acid/Ecoflex®/Modified Starch in Mandarin Orange Groves

    Directory of Open Access Journals (Sweden)

    Yasukatsu Maeda

    2009-08-01

    Full Text Available We have developed a mulch sheet made by inflation molding of PLA, Ecoflex® and modified starch, which all have different biodegradabilities. A field test of use as an agricultural mulch sheet for mandarin oranges was carried out over two years. The mechanical properties of the mulch sheet were weakened with time during the field test, but the quality of the mandarin oranges increased, a result of the controlled degradation of the sheet. The most degradable modified starch degraded first, allowing control of the moisture on the soil. Accelerator mass spectroscopy was used for evaluation of the biomass carbon ratio. The biomass carbon ratio decreased by degradation of the biobased materials, PLA and modified starch in the mulch sheet.

  2. The use of biodegradable mulch films in muskmelon crop production

    Directory of Open Access Journals (Sweden)

    Artur Saraiva

    2012-10-01

    Full Text Available Due to the large amount of mulch films used in agricultural crops and to all the environmental problems related with their disposal, the biodegradable mulch films seems to be the best solution for replacing the conventional polyethylene mulches. The main goal of this work was to evaluate and compare the performance of biodegradable mulch films with the conventional polyethylene ones in muskmelon culture during two years. Beyond fruit productivity and quality, the impact of each plastic in the soil moisture and temperature were also assessed. Taking into account that there are no reported biodegradation studies realized in Portugal, it was also important to verify the biodegradability of this new mulch films under the Portuguese soil conditions. The biodegradable mulch films did not show significant differences in fruit productivity and quality. The biodegradation rate of the mulches tested was not as high as would be expected. From the overall results obtained, biodegradable mulch films appear to be a good solution for the replacement of the conventional polyethylene mulches, however the Research and Development should continue to be done ton improve their biodegradation rate.

  3. The use of biodegradable mulch for tomato and broccoli production: Crop yield and quality, mulch deterioration, and growers' perceptions

    Science.gov (United States)

    Cowan, Jeremy Scott

    Biodegradable mulch may offer the benefits of polyethylene mulch for crop production with the added benefit of biodegradability. Four studies were carried out in Mount Vernon, WA to evaluate biodegradable mulch for tomato (Solanum lycopersicum L.) and broccoli (Brassica oleracea var. italica) production. The first study compared four biodegradable mulch treatments: BioAgri, BioTelo, WeedGuardPlus (cellulose product), and SB-PLA-10/11/12 (experimental, non-woven fabric), to polyethylene mulch and bare ground in high tunnels and in the open field for tomato yield and fruit quality over three growing seasons. Biodegradable plastic films produced yields and fruit quality comparable to polyethylene. Moreover, high tunnels increased total and marketable fruit weight five and eight times, respectively, compared to the open field. The second study quantified relationships among visual assessment parameters and mulch mechanical properties. Visual assessments and mechanical property tests of polyethylene, BioAgri, BioTelo, WeedGuardPlus, and SB-PLA-10/11/12, were made over three growing seasons. Regression analyses found the strongest relationship overall (r2 = 0.41) to be between the percent of initial breaking force in the machine direction and log 10 of percent visual deterioration. However, evaluating mulch products individually and increasing sample frequency are recommended for future research. The third study evaluated three biodegradable mulch products, BioAgri, Crown 1, and SB-PLA-11, after soil-incorporation. The average area of recovered mulch fragments decreased for all mulch products over time. The number of mulch fragments initially increased for all mulch products, with the greatest number of Crown 1 and BioAgri fragments recovered 132 and 299 days after incorporation, respectively. At 397 days after soil-incorporation, the total area of recovered fragments of Crown 1 and BioAgri was 0% and 34% of the theoretical maximum area, respectively. The fourth study

  4. Performance and environmental impact of biodegradable polymers as agricultural mulching films

    OpenAIRE

    Touchaleaume, François; Martin-Closas, Lluís; Angellier-Coussy, Hélène; Chevillard, Anne; Cesar, Guy; Gontard, Nathalie; Gastaldi, Emmanuelle

    2016-01-01

    In the aim of resolving environmental key issues such as irreversible soil pollution by non-biodegradable and non-recoverable polyethylene (PE) fragments, a full-scale field experiment was set up to evaluate the suitability of four biodegradable materials based on poly(butylene adipate-co-terephtalate) (PBAT) to be used as sustainable alternatives to PE for mulching application in vineyard. Initial ultimate tensile properties, functional properties during field ageing (water vapour permeabili...

  5. Performance and environmental impact of biodegradable polymers as agricultural mulching films.

    Science.gov (United States)

    Touchaleaume, François; Martin-Closas, Lluís; Angellier-Coussy, Hélène; Chevillard, Anne; Cesar, Guy; Gontard, Nathalie; Gastaldi, Emmanuelle

    2016-02-01

    In the aim of resolving environmental key issues such as irreversible soil pollution by non-biodegradable and non-recoverable polyethylene (PE) fragments, a full-scale field experiment was set up to evaluate the suitability of four biodegradable materials based on poly(butylene adipate-co-terephtalate) (PBAT) to be used as sustainable alternatives to PE for mulching application in vineyard. Initial ultimate tensile properties, functional properties during field ageing (water vapour permeability and radiometric properties), biodegradability and agronomical performance of the mulched vines (wood production and fruiting yield) were studied. In spite of their early loss of physical integrity that occurred only five months after vine planting, the four materials satisfied all the requested functional properties and led to agronomic performance as high as polyethylene. In the light of the obtained results, the mulching material lifespan was questioned in the case of long-term perennial crop such as grapevine. Taking into account their mulching efficiency and biodegradability, the four PBAT-based studied materials are proven to constitute suitable alternatives to the excessively resistant PE material. PMID:26386433

  6. Physical and Degradable Properties of Mulching Films Prepared from Natural Fibers and Biodegradable Polymers

    Directory of Open Access Journals (Sweden)

    Zhijian Tan

    2016-05-01

    Full Text Available The use of plastic film in agriculture has the serious drawback of producing vast quantities of waste. In this work, films were prepared from natural fibers and biodegradable polymers as potential substitutes for the conventional non-biodegradable plastic film used as mulching material in agricultural production. The physical properties (e.g., mechanical properties, heat preservation, water permeability, and photopermeability and degradation characteristics (evaluated by micro-organic culture testing and soil burial testing of the films were studied in both laboratory and field tests. The experimental results indicated that these fiber/polymer films exhibited favorable physical properties that were sufficient for use in mulching film applications. Moreover, the degradation degree of the three tested films decreased in the following order: fiber/starch (ST film > fiber/poly(vinyl alcohol (PVA film > fiber/polyacrylate (PA film. The fiber/starch and fiber/PVA films were made from completely biodegradable materials and demonstrated the potential to substitute non-biodegradable films.

  7. Biodegradation of poly(hydroxy butanoic acid) copolymer mulch films in soil

    Science.gov (United States)

    Kukade, Pranav

    Agricultural mulch films that are used to cover soil of crop rows contribute to earlier maturation of crops and higher yield. Incineration and landfill disposals are the most common means of disposal of the incumbent polyethylene (PE) mulch films; however, these are not environment friendly options. Biodegradable mulch films that can be rototilled into the soil after crop harvest are a promising alternative to offset problems such as landfill disposal, film retrieval and disposal costs. In this study, an in-house laboratory scale test method was developed in which the rate of disintegration, as a result of biodegradation of films based on polyhydroxybutanoic acid (PHB) copolymers was investigated in a soil environment using the residual weight loss method. The influence of soil composition, moisture levels in the soil, and industry-standard anti-microbial additive in the film composition on the rate of disintegration of PHB copolymer films was investigated. The soil composition has significant effect on the disintegration kinetics of PHB copolymer films, since the increasing compost levels in the soil lowered the rate of disintegration of the film. Also, with the increase in moisture level up to a threshold limit, the microbial activity and, hence, the rate of disintegration increased. Lastly, the developed lab-scale test protocol was found to be sensitive to even small concentrations of industry-standard antimicrobial additive in the film composition.

  8. Analysis of the degradation of biodegradable mulches in a pepper crop under organic management

    Science.gov (United States)

    Moreno, Carmen; González, Sara; Villena, Jaime; Meco, Ramón; María Moreno, Marta

    2016-04-01

    The use of biodegradable mulch materials (biopolymers and papers) as an alternative to polyethylene is increasing nowadays, particularly in organic farming, due to environmental factors. It is necessary to test their functionality under field conditions by identifying, for example, the undesirable early degradation which commonly takes place in some of these biodegradable materials. In this sense, it is quite common and easy to apply the use of visual scales to estimate the level of deterioration of mulches, which can be subjective. Therefore, the objectives of this work are: i) To study the degradation of different mulch materials under field conditions by measuring the soil surface they covered. ii) To compare these soil surface values with the overall assessment of their functionality obtained by visual scales. The trial was performed in an organically grown pepper crop in Ciudad Real (Central Spain) in the 2014 spring-summer season. The mulch materials used were: 1) black polyethylene (15 μm); black biopolymers (15 μm): 2) Mater-Bi® (corn starch based), 3) Sphere 4® (potato starch based), 4) Sphere 6® (potato starch based), 5) Bioflex® (polylactic acid based), 6) Ecovio® (polylactic acid based), 7) Mimgreen® (black paper, 85 g/m2). A randomized complete block design with four replications was adopted. The crop was drip irrigated following the water demand of each treatment. To assess the evolution of the soil surface covered by the mulches, a total of 560 photographs of the superficial (exposed) part and 196 photographs of the buried part of the materials (1415x2831 pixels, 28 pixels/cm) were analyzed by using Adobe Photoshop CS at 15, 30, 45, 60, 90,120, 145 days after transplanting. Additionally, four experts evaluated the functionality of these materials based on the photographs according to a scale from 1 (completely deteriorated material) to 9 (intact material). The results show: i) The superficial part corresponding to the polyethylene and the

  9. STUDY ON WET STRENGTH PERFORMANCE OF KENAF MULCH

    Institute of Scientific and Technical Information of China (English)

    Jinghui Zhou; Xinge Wu; Hongwei Zhu

    2004-01-01

    Optimum applied technical conditions of wet strength agent for kenaf mulch were studied in this article. Breaking length, wet-dry strength ratio, tear index and burst index of kenaf mulch were measured and optimum wet strength agent was selected. The aim is to make mulch have properties of heat preservation, humidity preservation, growth prompting, biodegradation and maximum wet strength and to improve impact resistance of mulch to rainwater so as to assure growth of plant and replace plastic film.

  10. Plastic Sheet-mulching for Yield Improvement of Summer Sweet Potato, Longshu 24%地膜覆盖栽培对夏薯‘龙薯24号’增产因素的探讨

    Institute of Scientific and Technical Information of China (English)

    梁金平

    2013-01-01

    以甘薯‘龙薯24号'为试验材料,采用随机区组设计,研究地膜覆盖栽培对夏薯产量和品质的影响.结果表明:覆膜可显著提高夏薯产量.覆膜栽培2年平均鲜薯产量为55.13 t·hm-2,比CK增产22.9%;覆膜栽培两年平均薯干产量为15.92 t·hm-2,比CK增产20.0%,差异达极显著水平.覆膜栽培收获期甘薯块根干物质含量比CK下降0.7%,总淀粉含量比CK下降0.61%,品质差异不显著.试验结果明确覆膜增产因素为覆膜栽培显著提高了单株薯块鲜重,降低了生长前期的T/R比值,提高了块根膨大高峰期的日鲜重增长速率.覆膜栽培生长过程土壤容重降低,土壤孔隙度提高,土壤通透性增强,土壤含水量相对稳定,覆膜栽培为甘薯的生长创造了良好的土壤环境,有利于根系发育,为块根的膨大奠定了良好的基础.覆膜栽培增效显著,每公顷可增加纯收入1.3万元.%By the randomized block design,effects of using plastic sheets for mulching on the yield and quality of the summer sweet potatoes,Longshu 24,were studied.The results showed that the plastic sheet-mulching increased the yield significantly.The average fresh tuber yield was 55.13 t · hm-2 from the two years experiment.It was higher than that of CK by 22.9%.The average yield of the sweet potato dry matters,from the two years experiment,was 15.92 t · hm-2.It was higher than that of CK by 20.0%.The differences were significant.The dry matter content of the sweet potatoes was lower than that of CK by 0.7 %,and the starch content was lower by 0.61%.There was no significant difference on the overall root quality during the harvest period.The reasons that the plastic sheet-mulching could promoted the sweet potato yield were believed to include:(a) the weight pre plant of the tuberous roots was increased significantly; (b) the T/R radio during early and mid growing stages was reduced,while the root development during the peak stage was enhanced

  11. Generating Elastic, Biodegradable Polyurethane/Poly(lactide-co-glycolide) Fibrous Sheets with Controlled Antibiotic Release via Two-Stream Electrospinning

    OpenAIRE

    Hong, Yi; FUJIMOTO, KAZURO; Hashizume, Ryotaro; Guan, Jianjun; Stankus, John J.; Tobita, Kimimasa; Wagner, William R.

    2008-01-01

    Damage control laparotomy is commonly applied to prevent compartment syndrome following trauma but is associated with new risks to the tissue, including infection. To address the need for biomaterials to improve abdominal laparotomy management, we fabricated an elastic, fibrous composite sheet with two distinct submicrometer fiber populations: biodegradable poly(ester urethane) urea (PEUU) and poly(lactide-co-glycolide) (PLGA), where the PLGA was loaded with the antibiotic tetracycline hydroc...

  12. Mulch materials in processing tomato: a multivariate approach

    Directory of Open Access Journals (Sweden)

    Marta María Moreno

    2013-08-01

    Full Text Available Mulch materials of different origins have been introduced into the agricultural sector in recent years alternatively to the standard polyethylene due to its environmental impact. This study aimed to evaluate the multivariate response of mulch materials over three consecutive years in a processing tomato (Solanum lycopersicon L. crop in Central Spain. Two biodegradable plastic mulches (BD1, BD2, one oxo-biodegradable material (OB, two types of paper (PP1, PP2, and one barley straw cover (BS were compared using two control treatments (standard black polyethylene [PE] and manual weed control [MW]. A total of 17 variables relating to yield, fruit quality, and weed control were investigated. Several multivariate statistical techniques were applied, including principal component analysis, cluster analysis, and discriminant analysis. A group of mulch materials comprised of OB and BD2 was found to be comparable to black polyethylene regarding all the variables considered. The weed control variables were found to be an important source of discrimination. The two paper mulches tested did not share the same treatment group membership in any case: PP2 presented a multivariate response more similar to the biodegradable plastics, while PP1 was more similar to BS and MW. Based on our multivariate approach, the materials OB and BD2 can be used as an effective, more environmentally friendly alternative to polyethylene mulches.

  13. Poly(lactic acid) and Osage Orange Wood Fiber Composites for Agricultural Mulch Films

    Science.gov (United States)

    Osage orange wood(OO)was combined with poly(lactic acid)(PLA)to form a polymer composite intended for use as an agricultural mulch film. The PLA-OO mechanical properties were comparable to existing mulch film products and had the advantage of being completely biodegradable through a single growing ...

  14. Image Analysis to Estimate Mulch Residue in Soil

    Science.gov (United States)

    Moreno, Carmen; Mancebo, Ignacio; Saa, Antonio; Moreno, Marta M.

    2014-01-01

    Mulching is used to improve the condition of agricultural soils by covering the soil with different materials, mainly black polyethylene (PE). However, problems derived from its use are how to remove it from the field and, in the case of it remaining in the soil, the possible effects on it. One possible solution is to use biodegradable plastic (BD) or paper (PP), as mulch, which could present an alternative, reducing nonrecyclable waste and decreasing the environmental pollution associated with it. Determination of mulch residues in the ground is one of the basic requirements to estimate the potential of each material to degrade. This study has the goal of evaluating the residue of several mulch materials over a crop campaign in Central Spain through image analysis. Color images were acquired under similar lighting conditions at the experimental field. Different thresholding methods were applied to binarize the histogram values of the image saturation plane in order to show the best contrast between soil and mulch. Then the percentage of white pixels (i.e., soil area) was used to calculate the mulch deterioration. A comparison of thresholding methods and the different mulch materials based on percentage of bare soil area obtained is shown. PMID:25309953

  15. Image Analysis to Estimate Mulch Residue in Soil

    Directory of Open Access Journals (Sweden)

    Carmen Moreno

    2014-01-01

    Full Text Available Mulching is used to improve the condition of agricultural soils by covering the soil with different materials, mainly black polyethylene (PE. However, problems derived from its use are how to remove it from the field and, in the case of it remaining in the soil, the possible effects on it. One possible solution is to use biodegradable plastic (BD or paper (PP, as mulch, which could present an alternative, reducing nonrecyclable waste and decreasing the environmental pollution associated with it. Determination of mulch residues in the ground is one of the basic requirements to estimate the potential of each material to degrade. This study has the goal of evaluating the residue of several mulch materials over a crop campaign in Central Spain through image analysis. Color images were acquired under similar lighting conditions at the experimental field. Different thresholding methods were applied to binarize the histogram values of the image saturation plane in order to show the best contrast between soil and mulch. Then the percentage of white pixels (i.e., soil area was used to calculate the mulch deterioration. A comparison of thresholding methods and the different mulch materials based on percentage of bare soil area obtained is shown.

  16. ‘White revolution’ to ‘white pollution’—agricultural plastic film mulch in China

    Science.gov (United States)

    Liu, E. K.; He, W. Q.; Yan, C. R.

    2014-09-01

    Plastic film mulching has played an important role in Chinese agriculture due to its soil warming and moisture conservation effects. With the help of plastic film mulch technology, grain and cash crop yields have increased by 20-35% and 20-60%, respectively. The area of plastic film coverage in China reached approximately 20 million hectares, and the amount of plastic film used reached 1.25 million tons in 2011. While producing huge benefits, plastic film mulch technology has also brought on a series of pollution hazards. Large amounts of residual plastic film have detrimental effects on soil structure, water and nutrient transport and crop growth, thereby disrupting the agricultural environment and reducing crop production. To control pollution, the Chinese government urgently needs to elevate plastic film standards. Meanwhile, research and development of biodegradable mulch film and multi-functional mulch recovery machinery will help promote effective control and management of residual mulch pollution.

  17. Effects of Film Mulch and Soil Pesticides on Nematodes, Weeds, and Yields of Vegetable Crops

    OpenAIRE

    Johnson, A. W.; Jaworski, C. A.; Glaze, N. C.; Sumner, D. R.; Chalfant, R. B.

    1981-01-01

    Field plots in Tifton loamy sand were treated with various soil pesticides in 1973 and 1974 and either left exposed or covered with biodegradable flint mulch. Test crops were cantaloup, slicing and pickling cucumber, squash, and sweet corn. Overhead sprinkler irrigation was used in 1973, and trickle irrigation under the film mulch was used on sweet corn in 1974. Soil was assayed for nematodes, and roots of plants were evaluated for damage by root-knot nematodes. Nematode populations were redu...

  18. Study of the degradation of mulch materials in vegetable crops for organic farming

    Science.gov (United States)

    María Moreno, Marta; Mancebo, Ignacio; Moreno, Carmen; Villena, Jaime; Meco, Ramón

    2014-05-01

    Mulching is the most common technique used worldwide by vegetable growers in protected cultivation. For this purpose, several plastic materials have been used, with polyethylene (PE) being the most widespread. However, PE is produced from petroleum derivatives, it is not degradable, and thus pollutes the environment for periods much longer than the crop duration (Martín-Closas and Pelacho, 2011), which are very important negative aspects especially for organic farmers. A large portion of plastic films is left on the field or burnt uncontrollably by the farmers, with the associated negative consequences to the environment (Moreno and Moreno, 2008). Therefore, the best solution is to find a material with a lifetime similar to the crop duration time that can be later incorporated by the agricultural system through a biodegradation process (Martín-Closas and Pelacho, 2011). In this context, various biodegradable materials have been considered as alternatives in the last few years, including oxo-biodegradable films, biopolymer mulches, different types of papers, and crop residues (Kasirajan and Ngouajio, 2012). In this work we evaluate the evolution of different properties related to mulch degradation in both the buried and the superficial (exposed) part of mulch materials of different composition (standard black PE, papers and black biodegradable plastics) in summer vegetable crops under organic management in Castilla-La Mancha (Central Spain). As results, it is remarkable the early deterioration suffered by the buried part of the papers, disappearing completely in the soil at the end of the crop cycles and therefore indicating the total incorporation of these materials to the soil once the crop has finished. In the case of the degradation of the exposed mulch, small differences between crops were observed. In general, all the materials were less degraded under the plants than when receiving directly the solar radiation. As conclusion, biodegradable mulches degrade

  19. Technique of green mulch spreading

    OpenAIRE

    Schäfer, Winfried; Väisänen, Jaana; Pihala, Marjo

    2001-01-01

    Finland’s policy of subsidising the conversion to organic production precipitated the rapid growth of organic farming in the 1990’s. As a consequence, many stockless farms encountered the problems of nitrogen deficit, poor grain quality, and weed control. Since the spreading of green mulch on cash crops is very common especially in tropical agriculture, organic fertilisers like green mulch may be an alternative that would compensate for the prohibition on the use of mineral N-fertilisers. How...

  20. Production of iceberg lettuce using mulches

    Directory of Open Access Journals (Sweden)

    Verdial Marcelo Fontanetti

    2001-01-01

    Full Text Available Mulches bring several benefits to lettuce cultivation. This work evaluated the effect of mulches on the cultivation of iceberg lettuce, cv. Lucy Brown. The treatment plots were: 1- no mulch and no weed control (control; 2- no mulch and weed control every 15 days; 3- sugarcane bagasse mulch of 2 cm thickness; 4- black plastic mulch; 5- double-faced plastic mulch (silver/black. Data were collected in regard to plant cycle when in the field, amount of chlorophyll in the leaves, productivity (individual weight per head and amount of nutrients absorbed by the leaves. Double-faced plastic mulch provides the highest productivity and the highest values for the amount of chlorophyll, nitrogen, phosphorus, sulfur, boron and iron accumulation in the leaves.

  1. Trichloroethylene (TCE) adsorption using sustainable organic mulch

    International Nuclear Information System (INIS)

    Soluble substrates (electron donors) have been commonly injected into chlorinated solvent contaminated plume to stimulate reductive dechlorination. Recently, different types of organic mulches with economic advantages and sustainable benefits have received much attention as new supporting materials that can provide long term sources of electron donors for chlorinated solvent bioremediation in engineered biowall systems. However, sorption capacities of organic mulches for chlorinated solvents have not been studied yet. In this study, the physiochemical properties of organic mulches (pine, hardwood and cypress mulches) were measured and their adsorption capacity as a potential media was elucidated. Single, binary and quaternary isotherm tests were conducted with trichloroethylene (TCE), tetrachloroethylene (PCE), trans-dichloroethylene (trans-DCE) and cis-dichloroethylene (cis-DCE). Among the three tested mulches, pine mulch showed the highest sorption capacity for the majority of the tested chemicals in single isotherm test. In binary or quaternary isotherm tests, competition among chemicals appears to diminish the differences in Qe for tested mulches. However, pine mulch also showed higher adsorption capacity for most chemicals when compared to hardwood and cypress mulches in the two isotherm tests. Based upon physicochemical properties of the three mulches, higher sorption capacity of pine mulch over hardwood and cypress mulches appears to be attributed to a higher organic carbon content and the lower polarity.

  2. Impact of mulches and growing season on indicator bacteria survival during lettuce cultivation.

    Science.gov (United States)

    Xu, Aixia; Buchanan, Robert L; Micallef, Shirley A

    2016-05-01

    In fresh produce production, the use of mulches as ground cover to retain moisture and control weeds is a common agricultural practice, but the influence that various mulches have on enteric pathogen survival and dispersal is unknown. The goal of this study was to assess the impact of different mulching methods on the survival of soil and epiphytic fecal indicator bacteria on organically grown lettuce during different growing seasons. Organically managed lettuce, cultivated with various ground covers - polyethylene plastic, corn-based biodegradable plastic, paper and straw mulch - and bare ground as a no-mulch control, was overhead inoculated with manure-contaminated water containing known levels of generic Escherichia coli and Enterococcus spp. Leaves and soil samples were collected at intervals over a two week period on days 0, 1, 3, 5, 7, 10 and 14, and quantitatively assessed for E. coli, fecal coliforms and Enterococcus spp. Data were analyzed using mixed models with repeated measures and an exponential decline with asymptote survival model. Indicator bacterial concentrations in the lettuce phyllosphere decreased over time under all treatments, with more rapid E. coli declines in the fall than in the spring (pmodel gave very good fits for the progression of E. coli concentrations in the phyllosphere over time (R(2)=0.88±0.12). In the spring season, decline rates of E. coli counts were faster (2013 p=0.18; 2014 psoil compared to lettuce phyllosphere, and mulch type was a factor for fecal coliform levels (pstudy demonstrates that mulches used in lettuce production may impact the fate of enteric bacteria in soil or on lettuce, most likely in relation to soil moisture retention, and other weather-related factors, such as temperature and rainfall. The data suggest that the time between exposure to a source of enteric bacteria and harvesting of the crop is season dependent, which has implications for determining best harvest times. PMID:26938806

  3. Mulching for sustainable use of saline water to grow tomato in sultanate of oman

    International Nuclear Information System (INIS)

    Tomato is grown in 991 hectares with production of 44477 tons in the sultanate of Oman. It is very important vegetable crop of Oman oat present being an integral part of daily diet of the people in various from like salad. Ketchup and kitchen cooking. Oman agriculture relies upon groundwater only, a major portion of which is saline that may concentrate further with the ever increasing pumping and probable seawater intrusions. Hence, the use of saline water is inevitable that can ultimately salinized the good productive soils. The production potential of these soils will gradually decrease and sustainability cannot be kept. This study was conducted to manage the saline water for avoiding bad effect on crop yields and soil health. A field experiment was conducted on tomato (Ginan variety) crop. Two mulching materials: organic matter (from date palm residues) and black plastic sheet, were tested in comparison to control (without any mulch). Two saline waters (EC=3 and 6 dSm/sup -1/) were used for irrigation. Uniform dose of fertilizers was applied. Four pickings of tomato were obtained and yield data were recorded EC moisture % age and temperature of soils were recorded after harvesting of crops. It was observed that data palm mulch proved as the most superior in terms of tomato fruit yield and control of increase in soil EC and temperature. It was followed by black plastic mulch. Both types of mulches indicated significant differences over control as well as among each other. (author)

  4. The influence of non-living mulch, mechanical and thermal treatments on weed population and yield of rainfed fresh-market tomato (Solanum lycopersicum L.

    Directory of Open Access Journals (Sweden)

    M. Fontanelli

    2013-06-01

    Full Text Available Weed control is often a major limitation for vegetable crops, since compared to arable crops fewer herbicides are available and the crops are more sensitive to weeds. Field experiments were carried out in the province of Pisa (Central Italy to determine the effect of two different mulches (black biodegradable plastic film and wheat straw and mechanical and thermal treatments on weed population and yield of rain-fed fresh market tomato (Solanum lycopersicum L.. Rolling harrow, flaming machine and precision hoe for weed control, which were either built, enhanced or modified by the University of Pisa were used separately (mechanical-thermal strategy or in combination with a straw mulch (mechanical-thermal-straw strategy. These two innovative strategies were compared with the traditional farming system, which uses a biodegradable plastic mulch film. The strategies were compared in terms of machine performance, weed density, total labour requirement, weed dry biomass, and crop fresh yield at harvest. The total operative time for weed control was on average ~25 h ha-1 for the two systems, which included mulching, and over 30 h ha-1 for the mechanical-thermal strategy. The three strategies controlled weeds effectively, with only 30 g m-2 in each treatment. Tomato yield, however, was 35% higher for strategies that included mulching (both biodegradable film and straw.

  5. Strawberry under low-tunnel protected with experimental biodegradable films

    International Nuclear Information System (INIS)

    A research was carried out in order to test innovative biodegradable materials for the protected cultivation of strawberry in Southern Italy. A field test was carried out in order to evaluate the agronomic performances of the biodegradable materials in comparison with non biodegradable LDPE materials. Different kinds of biodegradable black films were used for soil mulching and transparent biodegradable films for the covering of the low tunnels. Climatic data of the site, air temperature and relative humidity inside the low tunnels and soil temperature under the mulching films were gathered during the test. Besides, laboratory radiometric tests were executed on the films in order to evaluate parameters such as the transmissivity in different wavelength ranges. The biodegradable materials showed a high capacity to induce greenhouse effect due to their very low transmissivity in the long wave infrared range. The yield obtained using biodegradable materials was on average 12% higher then the one obtained with traditional films. Concerning the earliness, at the first day of the harvest, the yield obtained with biodegradable materials was 70% higher in comparison with the case of LDPE films. The research showed that the biodegradable materials could be a sustainable alternative to the plastic films based on fossil raw materials

  6. Mulch Treatment with Mulch Planter and its Effects on Maize Production

    OpenAIRE

    Nader Sakenian Dehkordi; Rouhollah Farhadi

    2016-01-01

    A study was done to develop management and protection of soil and water. The effect of rice husk as mulch was examined for maize production. The seeds of maize were planted in two different depths (4 and 6 cm) and the husk of rice was injected in different conditions (lateral part of row and sub row) by a mulch planter in a farm of Shahrekord. Different mulches were placed in soil (without mulch, 200, and 300 g per a meter of length). A factorial design based on complete randomized block wa...

  7. Mulch tillage for conserving soil water

    Science.gov (United States)

    Mulching is the practice of maintaining organic or inorganic materials on or applying them to the soil surface. It is an ancient practice, but through the years clean tillage that incorporated crop residues and also controlled weeds became the norm. Frequent and deep tillage often was promoted to co...

  8. Biodegradable Polymers

    OpenAIRE

    Isabelle Vroman; Lan Tighzert

    2013-01-01

    Biodegradable materials are used in packaging, agriculture, medicine and other areas. In recent years there has been an increase in interest in biodegradable polymers. Two classes of biodegradable polymers can be distinguished: synthetic or natural polymers. There are polymers produced from feedstocks derived either from petroleum resources (non renewable resources) or from biological resources (renewable resources). In general natural polymers offer fewer advantages than synthetic polymers. ...

  9. Phosphorus isothermal adsorption characteristics of mulch of bioretention

    Directory of Open Access Journals (Sweden)

    Mei Ying

    2012-01-01

    Full Text Available This study aims to identify mulch of bioretention which has high phosphorus sorption capacity. The phosphorus adsorption characteristics of five types of mulch of bioretention are studied by three isothermal adsorption experiments. Results show that the Langmuir eqution is suitable for describing absorption characteristics of five types of mulch. The positive values of Gibbs free energy for phosphorus indicate that the phosphorus biosorption by five mulches is a non-spontaneous process, and the values of mean sorption free energy of mulch are less than 8 kJ/mol, which proves that the adsorption process can be dominated by physical forces. The vermiculite is the better mulch of bioretention based on high phosphorus removal capacity.

  10. Application of Mulching Materials of Rainfall Harvesting System for Improving Soil Water and Corn Growth in Northwest of China

    Institute of Scientific and Technical Information of China (English)

    HAN Juan; JIA Zhi-kuan; HAN Qing-fang; ZHANG Jie

    2013-01-01

    The ridge and furrow rainfall harvesting (RFRH) system is used for dryland crop production in northwest of China. To determine the effects of RFRH using different mulching materials on corn growth and water use efifciency (WUE), a ifeld experiment was conducted during 2008-2010 at the Heyang Dryland Experimental Station, China. Four treatments were used in the study. Furrows received uncovered mulching in all RFRH treatments whereas ridges were mulched with plastic iflm (PF), biodegradable iflm (BF) or liquid iflm (LF). A conventional lfat ifeld without mulching was used as the control (CK). The results indicated that the average soil water storage at depths of 0-200 cm were 8.2 and 7.3%, respectively higher with PF and BF than with CK. However, LF improved soil water storage during the early growth stage of the crop. Compared with CK, the corn yields with PF and BF were increased by 20.4 and 19.4%, respectively, and WUE with each treatment increased by 23.3 and 21.7%, respectively. There were no signiifcant differences in corn yield or WUE with the PF and BF treatments. The net income was the highest with PF, followed by BF, and the 3-yr average net incomes with these treatments were increased by 2 559 and 2 430 CNY ha-1, respectively, compared with CK. BF and PF had similar effects in enhancing the soil water content, crop yield and net income. Therefore, it can be concluded that biodegradable iflm may be a sustainable ecological alternative to plastic iflm for use in the RFRH system in northwest of China.

  11. Root pruning reduces root competition in living mulch cropping systems

    OpenAIRE

    Båth, B.; Kristensen, Hanne Lakkenborg; Thorup-Kristensen, Kristian

    2009-01-01

    In intercropping systems with a cash crop and a living mulch intercrop, competition between the cash crop and the intercrop (the living mulch) often reduces the yield of the cash crop. This project investigated (1) the influence of root pruning of living mulches on aboveground biomass of white cabbage. Below-ground growth and competition were examined by measuring (2) root distribution in minirhizotrons and (3) uptake of 15N placed at different soil depths. Two field experiments were carried ...

  12. Mulch Induced Eco-physiological Growth and Yield of Maize

    OpenAIRE

    Awal, M. A.; M.A.H. Khan

    2000-01-01

    Mulching effects of sawdust, ash, rice straw and water hyacinth on growth, dry matter partitioning, earliness, yield attributes and yield of maize were studied. All mulches except sawdust significantly influenced the SLA, CGR, NAR and DM partitioning, but with no apparent effect on RGR. Water hyacinth and rice straw mulches hastened the tasseling, silking and maturity time by 6, 8 and 8 days respectively and produced double the amount of biological and economic yield as compared to the contro...

  13. Environmental controller of soil (mulch). Dojo kankyo chosetsu shizai-maruchi

    Energy Technology Data Exchange (ETDEWEB)

    Ishimoto, S. (Mikado Chemical M.F.G. Co., Chiba (Japan))

    1993-08-10

    Mulch for environmental controller of soil is divided into two types that are the best use of mulch using natural material and chemical material mulch. Stone mulch is the natural mulch and has been used in China for the cultivation of melon since about 500 years before. Plastic film mulch is used as chemical material mulch and is divided according to its purpose of use into light reflection film, light transparency suppression film, light transparent film, anti vaporization film, rain water permeation film, shock-proof film and so forth. As the weed growth was severe in case of transparent film mulch, the weed problem was solved by the development of black film or the film with weeding function prepared by mixing of polyethylene resin and weed killer. Besides, the development situation of green film mixing weed killer, light reflection type film mulch in tunnel cultivation, mulch to avoid virus diseases and non-woven cloth mulch are cited. 5 figs.

  14. Colored plastic mulch microclimates affect strawberry fruit yield and quality

    Science.gov (United States)

    Shiukhy, Saeid; Raeini-Sarjaz, Mahmoud; Chalavi, Vida

    2015-08-01

    Significant reduction of strawberry ( Fragaria × ananassa, Duch.) fruit yield and quality, as a consequence of conventional cultivation method, is common in the Caspian Sea region, Iran. Recently, growers started using plastic mulches to overcome these shortcomings. Plastic mulches have different thermal and radiation properties and could affect strawberry fruit yield and quality. In the present study, the effect of different colored plastic mulches (black, red, and white) along with conventional practice was tested on yield and quality of strawberry Camarosa cultivar, in a completely randomized block design. Colored plastic mulches had highly significant effect on fruit weight, size, and phytochemical contents. In the most harvest times, mean fruit weight was significantly higher in red plastic relative to white and control treatments. Total fruit weight of plastic mulches was not significantly different, while all were statistically higher than that of control. Fruit size significantly increased over red plastic mulch. Total fruit numbers over plastic mulches were significantly higher than that of control treatment. The content of phenolic compounds was similar between treatments, while anthocyanin content, IC50 value, and flavonoid content significantly were affected by colored plastics. In conclusion, colored plastic mulches could affect strawberry fruit weight and quality through altering strawberry thermal and radiation environment.

  15. The technology and mechanism of removal of plastic mulch and land preparation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Huiyou; HOU Shulin; NA Mingjun; YANG Xiaoli; BAI Shengnan

    2007-01-01

    In this article ,the characteristic of the field plastic mulch, the craft for mechanization removal and land preparation of plastic mulch and the mechanism frequently used in the removal and land preparation of plastic mulch were introduced, which offered references for the design of removal mechanism and land preparation of plastic mulch and structural optimization combination of working components.

  16. The application of a mulch biofilm barrier for surfactant enhanced polycyclic aromatic hydrocarbon bioremediation

    International Nuclear Information System (INIS)

    Lab scale mulch biofilm barriers were constructed and tested to evaluate their performance for preventing the migration of aqueous and surfactant solubilized PAHs. The spatial distribution of viable PAH degrader populations and resultant biofilm formation were also monitored to evaluate the performance of the biobarrier and the prolonged surfactant effect on the PAH degrading microorganism consortia in the biobarrier. Sorption and biodegradation of PAHs resulted in stable operation of the system for dissolved phenanthrene and pyrene during 150 days of experimentation. The nonionic surfactant could increase the solubility of phenanthrene and pyrene significantly. However, the biobarrier itself couldn't totally prevent the migration of micellar solubilized phenanthrene and pyrene. The presence of surfactant and the resultant highly increased phenanthrene or pyrene concentration didn't appear to cause toxic effects on the attached biofilm in the biobarrier. However, the presence of surfactant did change the structural composition of the biofilm. - Mulch biofilm barrier showed potential for surfactant enhanced bioremediation, and the presence of surfactant changed the structural composition of the biofilm

  17. Effect of Different Mulches under Rainfall Concentration System on Corn Production in the Semi-arid Areas of the Loess Plateau

    Science.gov (United States)

    Ren, Xiaolong; Zhang, Peng; Chen, Xiaoli; Guo, Jingjing; Jia, Zhikuan

    2016-01-01

    The ridge and furrow farming system for rainfall concentration (RC) has gradually been popularized to improve the water availability for crops and to increase the water use efficiency (WUE), thereby stabilizing high yields. In the RC system, plastic-covered ridges are rainfall harvesting zones and furrows are planting zones. In this study, we optimized the mulching patterns for RC planting to mitigate the risks of drought during crop production in semi-arid agricultural areas. We conducted a four-year field study to determine the effects on corn production of mulching with 0.08-mm plastic film, maize straw, 8% biodegradable film, liquid film, bare furrow, and conventional flat (CF) farming. We found that RC significantly increased (P > 0.05) the soil moisture storage in the top 0-100 cm layer and the topsoil temperature (0-10 cm) during the corn-growing season. Combining RC with mulching further improved the rain-harvesting, moisture-retaining, and yield-increasing effects in furrows. Compared with CF, the four-year average yield increased by 1497.1 kg ha-1 to 2937.3 kg ha-1 using RC with mulch treatments and the WUE increased by 2.3 kg ha-1 mm-1 to 5.1 kg ha-1 mm-1.

  18. Mulch Treatment with Mulch Planter and its Effects on Maize Production

    Directory of Open Access Journals (Sweden)

    Nader Sakenian Dehkordi

    2016-05-01

    Full Text Available 800x600 Normal 0 21 false false false HR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-fareast-language:EN-US;} A study was done to develop management and protection of soil and water. The effect of rice husk as mulch was examined for maize production. The seeds of maize were planted in two different depths (4 and 6 cm and the husk of rice was injected in different conditions (lateral part of row and sub row by a mulch planter in a farm of Shahrekord. Different mulches were placed in soil (without mulch, 200, and 300 g per a meter of length. A factorial design based on complete randomized block was performed. Indices of plant height, weight of ear, diameter of ear, length of ear, weight of ear sheath, height growth rate of plant, and seed numbers in each ear were measured. Results showed that differences were significant in the indices of plant height, height growth rate of plant, and seed numbers in each ear. In the other indices were not seen significant differences. The results also showed that there was no significant difference in the weight of ear and ear sheath. The depth of 6 cm, 300 g mulch per a meter, and injected mulch in the lateral part of row enhanced growth of plant height and seed numbers in each ear. Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4

  19. Cell sheet engineering

    Directory of Open Access Journals (Sweden)

    Masayuki Yamato

    2004-05-01

    Full Text Available We have developed ‘cell sheet engineering’ in order to avoid the limitations of tissue reconstruction using biodegradable scaffolds or single cell suspension injection. Our concept is tissue reconstruction, not from single cells, but from cell sheets. Cell sheets are prepared using temperature-responsive culture dishes. Temperature-responsive polymers are covalently grafted onto the dishes, allowing various types of cells to adhere and proliferate at 37°C. The cells spontaneously detach when the temperature is reduced below 32°C without the need for proteolytic enzymes. The confluent cells are noninvasively harvested as single, contiguous cell sheets with intact cell-cell junctions and deposited extracellular matrix (ECM. We have used these harvested cell sheets for various tissue reconstructions, including ocular surfaces, periodontal ligaments, cardiac patches, and bladder augmentation.

  20. SOIL MULCHING WITH STRAW IN BROCCOLI CULTIVATION FOR EARLY HARVEST

    OpenAIRE

    Edyta Kosterna

    2014-01-01

    All treatments which protect soil from degradation and use of plant protection methods, other than chemicals are of great importance in the cultivation. This effect is attributed, among others, to organic mulches. By limiting the growth of weeds, maintaining proper moisture and reducing daily temperature fluctuations, mulch improves soil conditions for plant growth and development. The experiment was carried out between 2010 and 2012 at the Experimental Farm in Zawady as a split-block design ...

  1. EFFECT OF LIVING MULCH ON PEST/BENEFICIAL INTERACTION

    OpenAIRE

    Burgio, Giovanni; Kristensen, Hanne L.; Campanelli, Gabriele; Bavec, Franc; Bavec, Martina; von Fragstein und Niemsdorff, Peter; Depalo, Laura; Lanzoni, Alberto; Canali, Stefano

    2014-01-01

    The aim of this study was to evaluate the effect of cover crops on pest/beneficial dynamics and to test the potential of living mulch on enhancing biological control against insect pests. The research, carried out in the frame of the InterVeg (Core Organic II) project, involved four European countries: Germany, Slovenia, Denmark and Italy. Three crops were tested: cauliflower, leek and artichoke. The preliminary results obtained in Italy on cauliflower, indicated that the living mulch did not...

  2. Soil Air Regime of Corn Field Under Plastic Mulching

    Institute of Scientific and Technical Information of China (English)

    CHENYONG-XIANG; LIUXIAO-YI; 等

    1995-01-01

    The effects of plastic mulching on soil aeration at the soil depth of 0-100 cm were studied in a corn field.The results indicated that the CO2 concentration of unmulched soil in the 0-100 cm layer ranged from 0.001 to 0.016 m3/m3,and that of mulched oil 0.002 to 0.018m3/m3,about 32,39% higher than the former on the average.Such a CO2 concentration in the soil air is still sutiable for crop growth.The O2 concentration was inversely correlated with CO2 concentration in the soil air (unmulching r=-0.92,mulching r=-0.79*).O2 concentration raged from 0.11 to 0.17m3/m3 in the mulched soil and 0.13 to 0.18m3/m3 in the unmulched soil.By contrast,N2 concentration in soil air remained relatively steady,with no difference between the two treatments.The relationship between the soil respiratory intensity and the depth of a soil layer appeard to be a power function.At the layer of 0-20cm,the soil respiration intensity in the mulched soil was obviously higher than that in the unmulched.Plastic mulching could also affect soil structure.In comparison with the unmulched soil,the content of >0.25mm aggregate and 0.05-0.001mm microaggregate in the mulched soil was reduced by 82.1% and 35.8%,respectively;the soil total porotity,gaseous phase rate and aeration porosity in the depth of 10-20cm were reduced by 2.85%,19.89%and 26.54% respectively ,but contrary at the depth of 0-10cm.

  3. Alteration of Soil Temperature and Moisture Through Mulching on the Morpho-physiological Differentiation in Maize

    OpenAIRE

    Awal, M. A.; M.A.H. Khan

    1999-01-01

    Mulching effects of sawdust, ash, rice straw and water hyacinth on the morpho-physiological differentation of maize (Zea mays L.) and to relate these with soil environment were described. Water hyacinth and rice straw mulches had significant promotive effects on shoot elongation, root penetration, LAI and DM accumulation. All mulches conserved soil moisture but water hyacinth and rice straw retained comparatively greater amount. Water hyacinth and rice straw mulches reduced soil temperature f...

  4. Monitoring Plastic-Mulched Farmland by Landsat-8 OLI Imagery Using Spectral and Textural Features

    OpenAIRE

    Hasituya; Zhongxin Chen; Limin Wang; Wenbin Wu; Zhiwei Jiang; He Li

    2016-01-01

    In recent decades, plastic-mulched farmland has expanded rapidly in China as well as in the rest of the world because it results in marked increases of crop production. However, plastic-mulched farmland significantly influences the environment and has so far been inadequately investigated. Accurately monitoring and mapping plastic-mulched farmland is crucial for agricultural production, environmental protection, resource management, and so on. Monitoring plastic-mulched farmland using moderat...

  5. SOIL MULCHING WITH STRAW IN BROCCOLI CULTIVATION FOR EARLY HARVEST

    Directory of Open Access Journals (Sweden)

    Edyta Kosterna

    2014-04-01

    Full Text Available All treatments which protect soil from degradation and use of plant protection methods, other than chemicals are of great importance in the cultivation. This effect is attributed, among others, to organic mulches. By limiting the growth of weeds, maintaining proper moisture and reducing daily temperature fluctuations, mulch improves soil conditions for plant growth and development. The experiment was carried out between 2010 and 2012 at the Experimental Farm in Zawady as a split-block design with three replicates. The effect of the kind of straw (rye, corn, rape, buckwheat and its dose (10 and 20 t∙ha-1 applied as a mulch on the yield and quality of broccoli ‘Milady F1’ cultivated for early harvest was investigated. The effect of straw was compared to a control plot without mulch. Weather conditions in the successive years of the study had a significant influence on the yield and quality of broccoli. The highest yields with the best parameters were obtained in 2010 and 2012, which were characterized by sufficient rainfall for broccoli. It was not found significant differences in the yield level and weight of head between particular kinds of straw, however, all kinds of straw investigated in the experiment, irrespective of dose, contributed to a significant increase in the yield and favourably influenced the biometric features of broccoli compared to that achieved from cultivation without straw. Soil mulching with corn straw was most favourable to yield and its parameters.

  6. Biodegradation of photo-degraded mulching films based on polyethylenes containing polyethylene oxide modified TiO2 as pro-oxidant additives%光氧化TiO2/PEO/LDPE复合薄膜的生物降解性能

    Institute of Scientific and Technical Information of China (English)

    杨薇; 杨玉鹰; 蔡亦金; 张桂乔; 罗颖

    2016-01-01

    The photodegradable TiO2/PEO/LDPE composite film was prepared by an addition of TiO2 as a pro-oxidant containing polyethylene oxide (PEO)into commercial LDPE.The biological mineralization in a seal composting environment and microbial degradation of oxidized LDPE were studied.The results show that the intensities of carbonyl group peak in the TiO2/PEO/LDPE composite film with exposed to UVA340 irradiation for 600 h increased would be due to ester,acid and aldehyde compounds,which were produced by LDPE degra-dation,increased in films and the structure of TiO2/PEO/LDPE composite film destroyed clearly.The TiO2/PEO/LDPE composite films with pro-oxidant exposed to UV irradiation followed by compost for 180 days or soil microbial degradation for 254 days.In this process,the mineralization rate of TiO2/PEO/LDPE composite film reached 1 5 .2 6%.On the other hand,microscopic examination showed a profuse mycelia growth and spores on the oxidized TiO2/PEO/LDPE composite films,which illustrated that the soil microbial were fully capable of utilizing degradation products as a carbon source.The addition of PEO improves the hydrophilicity of nano-TiO2 in LDPE matrix,thus the photocatalytic degradation efficiency increases facilitating the oxo-degradation of LDPE greatly which promotes the subsequent biodegradation.%以聚氧乙烯(PEO)为亲水改性剂、纳米 TiO2颗粒作为光催化助氧剂,与低密度聚乙烯(LDPE)树脂复合制备了光氧化-生物降解TiO2/PEO/LDPE 纳米复合薄膜。通过密封堆肥和土壤微生物的降解实验,研究了该复合薄膜在空气中紫外光氧化降解后的生物降解性能。结果表明,TiO2/PEO/LDPE 复合薄膜在 UVA340的紫外光照射600 h后,发生了明显的降解,羰基指数增大,产生了大量羰基类的化合物,结构发生明显的破坏;光氧化后的薄膜碎片经过180 d的堆肥或254 d的土壤微生物降解后,其矿化率达到15.26%,薄膜表面长满了孢子及大量的菌丝,能够

  7. Biodegradation of plastics in soil and effects on nitrification activity. A laboratory approach.

    Directory of Open Access Journals (Sweden)

    Giulia eBettas Ardisson

    2014-12-01

    Full Text Available The progressive application of new biodegradable plastics in agriculture calls for improved testing approaches to assure their environmental safety. Full biodegradation (≥ 90% prevents accumulation in soil, which is the first tier of testing. The application of specific ecotoxicity tests is the second tier of testing needed to show safety for the soil ecosystem. Soil microbial nitrification is widely used as a bioindicator for evaluating the impact of chemicals on soil but it is not applied for evaluating the impact of biodegradable plastics. In this work the International Standard test for biodegradation of plastics in soil (ISO 17556, 2012 was applied both to measure biodegradation and to prepare soil samples needed for a subsequent nitrification test based on another International Standard (ISO 14238, 2012. The plastic mulch film tested in this work showed full biodegradability and no inhibition of the nitrification potential of the soil in comparison with the controls. The laboratory approach suggested in this Technology Report enables (i to follow the course of biodegradation, (ii a strict control of variables and environmental conditions, (iii the application of very high concentrations of test material (to maximize the possible effects. This testing approach could be taken into consideration in improved testing schemes aimed at defining the biodegradability of plastics in soil.

  8. Termites and mulch work together to rehabilitate soils

    NARCIS (Netherlands)

    Ouédraogo, E.; Mando, A.; Brussaard, L.

    2008-01-01

    In semi-arid areas such as the Sahelian zone of Africa, many soils have become severely degraded. One extreme form is the bare and crused soil, which is virtually productively "dead". In Burkina Faso, farmers have responded by applying mulch to attract termites that then help to rehabilitate the soi

  9. Effects of gravel mulch on emergency of galleta grass seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Winkel, V.K.; Medrano, J.C.; Stanley, C.; Walo, M.D.

    1993-02-01

    Gravel mulches show promise as effective material on the US Dept. of Energy Nevada Test Site for stabilizing erosive soils and aiding plant establishment by conserving soil water. A greenhouse study was implemented to determine the effects of gravel mulch on seedling emergence and soil water, and optimal depths of gravel for various native plant species. Greenhouse flats were sown with seeds of nine species of native grasses, forbs, and shrubs. The flats were then treated with a variety of mulch treatments including, no mulch, a 1-cm layer of soil over seeds, and 2 to 3-cm and 4 to 5-cm layers of 3 to 25-mm mixed gravel. Superimposed over these treatments were 3 irrigation treatments. Seedling density data was collected daily, and soil water was monitored daily with the gravimetric method. This study showed that under a variety of soil water conditions, a 2--3 cm gravel layer may aid emergence of galleta grass. Results from this study also demonstrated that a deeper layer of gravel (4--5 cm) prohibits emergence, probably because it acts as a physical barrier to the seedlings. Galleta grass emergence can be used as a model for how other species might respond to these seedbed and irrigation treatments, provided they have adequate germination and are exposed to similar environmental conditions.

  10. Herbicide dissipation from low density polyethylene mulch utilizing analytical techniques

    Science.gov (United States)

    In Georgia, most of the low density polyethylene mulch (LDPM) is laid for spring vegetable production followed by a second crop in the autumn, with a potential third crop the following spring. Between these vegetable plantings, farmers often use contact and residual herbicides to control weeds that ...

  11. Influence of Container Mulches on Irrigation and Nutrient Management

    Science.gov (United States)

    An experiment was conducted in 2005 and repeated in 2006 to determine the influence of mulch products and controlled release fertilizer (CRF) placement on irrigation and nutrition requirements of container-grown crops. Hydrangea (Hydrangea macrophylla 'Fasan' and 'Endless Summer') were grown in 2.7...

  12. Proceedings of biodegradation

    International Nuclear Information System (INIS)

    This book contains the proceedings of Biodegradation. Topics include:biodegradation using the tools of biotechnology, basic science aspects of biodegradation, the physiological characteristics of microorganisms, the use of selective techniques that enhance the process of microbial evolution of biodegradative genes in nature, the genetic characteristics of microorganisms allowing them to biodegrade both natural and synthetic toxic chemicals, the molecular techniques that allow selective assembly of genetic segments form a variety of bacterial strains to a single strain, and methods needed to advance biodegradation research as well as the high-priority chemical problems important to the Department of Defense or to the chemical industry

  13. Economic assessment of different mulches in conventional and water-saving rice production systems.

    Science.gov (United States)

    Jabran, Khawar; Hussain, Mubshar; Fahad, Shah; Farooq, Muhammad; Bajwa, Ali Ahsan; Alharrby, Hesham; Nasim, Wajid

    2016-05-01

    Water-saving rice production systems including alternate wetting and drying (AWD) and aerobic rice (AR) are being increasingly adopted by growers due to global water crises. Application of natural and artificial mulches may further improve water economy of water-saving rice production systems. Conventionally flooded rice (CFR) system has been rarely compared with AWD and AR in terms of economic returns. In this 2-year field study, we compared CFR with AWD and AR (with and without straw and plastic mulches) for the cost of production and economic benefits. Results indicated that CFR had a higher production cost than AWD and AR. However, application of mulches increased the cost of production of AWD and AR production systems where plastic mulch was expensive than straw mulch. Although the mulching increased the cost of production for AWD and AR, the gross income of these systems was also improved significantly. The gross income from mulched plots of AWD and AR was higher than non-mulched plots of the same systems. In conclusion, AWD and AR effectively reduce cost of production by economizing the water use. However, the use of natural and artificial mulches in such water-saving environments further increased the economic returns. The maximized economic returns by using straw mulch in water-saving rice production systems definitely have pragmatic implications for sustainable agriculture. PMID:26832873

  14. Effects of Mulching Mode on Canopy Physiological, Ecological Characteristics and Yield of Upland Rice

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-zhu; LIU Yang; ZENG Xiang; CHEN Kai-lin; HUANG Zc-hui; XIE Hong-ke

    2011-01-01

    The effects of mulching mode on population physiology and ecology of rice were studied using a combination P88S/1128 as the material under three mulching cultivation modes including plastic film mulching,straw mulching and liquid film mulching,as well as bare cultivation (control).The results indicated that mulching mode had significant effects on micro-meteorological factors and individual growth of rice,as shown by an increase of relative humidity,a better internal micro-meteorological environment of rice population,a significant reduction under the rice canopy temperature,especially during high-temperature periods.Rice plants under mulching cultivation conditions displayed a stronger transpiration and lower leaf temperature,thereby improving the ability of anti-high temperature stress and markedly increasing the photosynthetic rate.Furthermore,the yield components of rice were significantly optimized under mulching cultivation,of which with plastic film mulching displayed the highest grain number per panicle and seed-setting rate,and a yield increase of 16.81% compared with the control; and with straw mulching displayed an increase of effective panicle number and a 9.59%increase of total yield compared to the control.

  15. Short Communication: Effect of mulching materials on mini tuber production of potato from in vitro plantlets

    Directory of Open Access Journals (Sweden)

    D.A.N. MAJUMDER

    2016-06-01

    Full Text Available Abstract. Majumder DAN, Nath SC, Kabir MA, Majumder S. 2016. Effect of mulching materials on mini tuber production of potato from in vitro plantlets. Nusantara Bioscience 8: 123-127. This paper describes the effectiveness of organic and plastic mulching for potato mini tuber production in Bangladesh. The field experiment was carried out during the Rabi season of 2013-2014 to 2014-2015 with virus free in vitro cultured plantlets of var. Diamant. The mulching materials of water hyacinth mulch (WHM, rice straw mulch (RSM and black polythene mulch (BPM were compared to no-mulching (control to find out suitable mulching material (s for obtaining higher tuber yield. During the whole production period morphological characters, yield characters as well as of soil temperature and soil moisture were assessed. The results showed that WHM (5.28 t/ac and RSM (4.59 t/ac had a positive effect on increased the proportion of tuber size above 28 mm and on increasing of tuber yields by 54.0% to 77.2% compared with control (2.98 t/ac. Higher soil temperatures were recorded with plastic mulch caused lower potato tuber yield (3.04 t/ac while WHM and RSM decreased soil temperatures and increased the moisture percentage. The mulching of mini tubers had negative effect on tubers quality in regards of scab, green tuber and weed biomass.

  16. The effects of mulch types on earliness, fruit set ratios, and yield for apricot

    Directory of Open Access Journals (Sweden)

    Burcu YAMAN

    2013-12-01

    Full Text Available The objective of this study is to enhance earliness and fruit set, which is a crucial factor in apricot production. The study was conducted on an apricot orchard located in Serinyol town of Antakya between 2010 and 2011. In the experiment, ‘Ninfa’, ‘Bebeco’, ‘Aurora’ and ‘Roksana’ cultivars were used. The experimental cultivars were planted on 3 x 6 m in 2006 as one-year-old plants budded on seedling rootstocks. The plants have been irrigated by drip irrigation since their transplantation. In the experiment, there were four treatments as follows: control, transparent polyethylene mulch, organic mulch, and transparent polyethylene mulch + organic mulch. As plastic mulch, a 0.02 mm (UV+AB transparent plastic 1.60 cm in width; and, wheat straw as organic mulch was used. The experiment was designed as split-plot experimental design with 5 replications having 1 tree in each replication. The mulch was applied based on the physiological stages of the trees; prior to break of dormancy and opening of the buds. In the study, phenological observations (first flowering, full flowering and the end of the flowering as well as fruit set ratios, the status of vegetative development and yield were determined. As a result, in the both years, the flowering and fruit set ratios of control trees were found lower than the organic mulch or plastic mulch treated trees. Mulching treatments were enhanced 2-4 days earliness compared to control treatment for fruit maturity; and transparent polyethylene mulch + organic mulch was found partially better than the others two mulching treatments.

  17. The effect of mulch and fertilizers on broccoli (Brassica oleracea L. Var. Italica oxidants and antioxidants

    Directory of Open Access Journals (Sweden)

    Ali Husain Jasim

    2014-11-01

    Full Text Available Factorial field experiments was conducted during 2012/2013 growth season to study the effect of soil mulch (mulch and without mulch and some fertilizers (control, sulfur, organic and high potash fertilizer on H2O2 content and the activity of catalase (CAT, superoxide dismutase (SOD, and glutathione (GSH oxidative enzymes of broccoli leaves and flowers. The results showed that using mulch, fertilizer treatment and the interaction between mulch and high potash treatment led to a significant increase in CAT and SOD activity. Furthermore, high potash and sulfur supplementation caused a significant increase in broccoli antioxidants both in leaves and flowers respectively. We conclude that mulch and high potash treatment led to increase plant tolerance to salt stress by increasing antioxidant mechanisms.

  18. Tomato response to starter fertilizer, polyethylene mulch, and level of soil phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Grubinger, V.P.; Minotti, P.L.; Wien, H.C.; Turner, A.D. (Cornell Univ., Ithaca, NY (United States). Dept. of Fruit and Vegetable Science)

    1993-03-01

    Unmulched and polyethylene-mulched tomatoes (Lycopersicon esculentum Mill.) were grown with and without starter fertilizer (SF) in four field experiments. The field varied as to residual P level and the amount of P incorporated before planting. No benefits from SF were obtained on a soil with high residual P that was moderately fertilized with P before transplanting or on a soil with low residual P that was heavily fertilized with P. A positive effect from SF was observed only when residual P was low and no P was broadcast, and this was true in mulched and unmulched plots. No significant SF by mulch interaction was obtained in these experiments even though mulching consistently increased shoot P concentrations and fruit yield. The mulch was beneficial even under conditions where unmulched tomato leaves contained 0.4% P 3 weeks after transplanting, indicating that factors in addition to improved P nutrition are also involved in the mulch effect.

  19. Metalized Polyethylene Mulch to Reduce Incidence of Huanglongbing and Improve Growth of New Citrus Plantings

    OpenAIRE

    Croxton, S.; Stansly, P.

    2014-01-01

    Polyethylene mulch was evaluated for deterring colonization by Asian citrus psyllid (ACP) Diaphorina citri, reducing incidence of huanglongbing (HLB) or citrus greening disease and accelerating growth of young citrus.  UV reflective low density polyethylene mulch metalized with aluminum, low density whitefaced polyethylene mulch and bare ground all using drip irrigation in a randomized complete block design were tested and compared to the current grower standard using micro-sprinkler irrigati...

  20. Effect of organic mulching on physico-chemical properties of soil

    International Nuclear Information System (INIS)

    Rice straw is used as organic mulch to regulate the hydrothermal regime of the soil. It is also used for moisture conservation, soil temperature moderation and weed suppression. Attempts were made to study the physico-chemical properties of soil through a series of experiments at four different locations of lateritic sandy loam soil of India under straw mulch. It was concluded that rice straw might be used as a nutrient source in crop production and act as mulch-cum manure. (author)

  1. Effectiveness of Straw Mulch on Infiltration, Splash Erosion, Runoff and Sediment in Laboratory Conditions

    OpenAIRE

    Gholami Leila; Banasik Kazimierz; Sadeghi Seyed Hamidreza; Khaledi Darvishan Abdulvahed; Hejduk Leszek

    2014-01-01

    Mulches have extraordinary potential in reducing surface runoff, increasing infiltration of water into the soil and decreasing soil erosion. The straw mulches as a biological material, has the ability to be a significant physical barrier against the impact of raindrops and reduce the detachment of soil aggregates. The present study is an attempt to determine the efficiency of straw mulch as conservation treatment in changes in the splash erosion, time-to-runoff, runoff coefficient, infiltrati...

  2. Effects of soil tillage and mulching on thermal performance of a Luvisol topsoil layer

    OpenAIRE

    Andrade, J. A.; Alexandre, C.A.; Basch, G.

    2010-01-01

    Important energy exchanges at soil surface regulate the thermal environment within top soil layer and the boundary layer above it. By this reason, the application of mulches or the modelling of micro relief by soil tillage are common practises to modify the thermal regime of a soil. The aim of this study is to compare the effect on thermal behaviour of a Luvisol resulting of soil tillage and the application of stubble mulch and, different amounts of straw mulch. For this purpose, experi...

  3. Polyethylene mulch stimulates early root growth and nutrient uptake of transplanted tomatoes

    Energy Technology Data Exchange (ETDEWEB)

    Wien, H.C.; Minotti, P.L.; Grubinger, V.P. (Cornell Univ., Ithaca, NY (United States). Dept. of Fruit and Vegetable Science)

    1993-03-01

    Tomato (Lycopersicon esculentum Mill.) plants grown on polyethylene (PE) mulch in New York State frequently have more branches and increased mineral nutrient uptake and yield than plants not mulched. In four field experiments conducted on a silt loam soil, clear PE mulch stimulated root extension shortly after transplanting. One week after transplanting, roots were significantly longer for mulched than for unmulched plants in all four experiments, whereas above ground dry matter differences did not become significant until 14 days after transplanting in two of four trials. Mulching increased branching, hastened flowering on basal branches, and increased concentration of major nutrients in the above ground parts. In the field, stimulation of above ground growth due to mulch might be brought about by warming of the stem by air escaping from the planting hole in the mulch. However, an experiment with black, white, or clear mulch, in which the planting hole was either left uncovered or covered with soil, showed no effect of hole closure on branching even though air temperature near the stem was increased when holes were left uncovered. The results taken together imply that the increased above ground growth observed with mulching is a consequence of enhanced root growth and nutrient uptake.

  4. THE EFFECT OF DIFFERENT TYPES OF STRAW MULCHES ON WEED-CONTROL IN VEGETABLES CULTIVATION

    OpenAIRE

    Edyta Kosterna

    2014-01-01

    The experiment was carried out in 2010–2012. The effect of different kinds of straw and its dose applied to soil mulching on the amount and fresh mass of weeds and yield level of broccoli and tomato was investigated. The type of straw mulch applied to the soil mulching influenced number and fresh mass of weeds. This effect could be the result of the properties of the mulch (colour, structure, etc.) or the allelopathic effect on the germination and growth of individual weed species. The most e...

  5. Vegetative and reproductive evaluation of hot peppers under different plastic mulches in poly/plastic tunnel

    International Nuclear Information System (INIS)

    Since the beginning of civilization, the man has developed technologies to increase the efficiency of food production. The use of plastic mulch in commercial vegetable production is one of these traditional techniques that have been used for centuries. Studies were conducted to assess the efficacy of plastic mulch on growth and yield of two hot pepper hybrids, viz. Sky Red and Maha in poly/plastic tunnel. The treatments were black plastic mulch, clear plastic mulch and bare soil as control. Both hot pepper hybrids mulched with black plastic showed significantly better vegetative growth (plant height, leaf area etc) and fruit yield. Clear plastic mulch significantly increased soil temperature and reduced the number of days to first flower than black plastic mulch and bare soil. However, fruit yield was higher by 39.56 and 36.49% respectively in both hybrids when they were grown on black and clear plastic mulch as compared to bare soil. Overall results indicated that the use of plastic mulch is an ideal option to maximize hot pepper productivity as well as to extend their production season in poly/plastic tunnels. (author)

  6. Application of date palm trees mulch as a bedding material for dry heifers in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Sadik M.W

    2012-09-01

    Full Text Available A study was conducted to determine the safety of using Saudi date palm trees mulch as a bedding material for dry heifers. Date palm trees mulch was used as bedding material for 10 days. Final Composite regulated elements (N, P, K, Na, Ca, and Mg, NDF, ADF, pH, moisture, and EC were improved by use of date palm trees mulch as a bedding material especially in concrete area (1.85%, 0.50%, 1.42%, 0.59%, 2.56%, 0.26%, 60.00%, 49.40%, 7.53, 30%, 16.88 for N, P, K, Na, Ca. Mg, NDF, ADF, pH, Moisture and Electrical conductivity, respectively. On a dry matter basis, highly enriched element fresh manure was collected from the concrete section bedded with date palm trees mulch. Both Concrete area bedded with date palm trees mulch and Sand area bedded with date palm trees mulch were free of salmonella after 10 days. Date palm trees mulch was unsuitable medium for pathogenic bacteria especially Escherichia coli O157:H7 .Total viable bacterial counts failed to increase with the incubation time (104. Date palm tree mulch was unsuitable medium for flies and minimizes density of house flies. Date palm trees mulch seemed to be a safe, comfortable and effective bedding material for cow’s feedlots.

  7. Soil mulching significantly enhances yields and water and nitrogen use efficiencies of maize and wheat: a meta-analysis

    Science.gov (United States)

    Qin, Wei; Hu, Chunsheng; Oenema, Oene

    2015-11-01

    Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil characteristics, crop species, and also water and nitrogen (N) input levels. Here we report on a meta-analysis of the effects of mulching on wheat and maize, using 1310 yield observations from 74 studies conducted in 19 countries. Our results indicate that mulching significantly increased yields, WUE (yield per unit water) and NUE (yield per unit N) by up to 60%, compared with no-mulching. Effects were larger for maize than wheat, and larger for plastic mulching than straw mulching. Interestingly, plastic mulching performed better at relatively low temperature while straw mulching showed the opposite trend. Effects of mulching also tended to decrease with increasing water input. Mulching effects were not related to soil organic matter content. In conclusion, soil mulching can significantly increase maize and wheat yields, WUE and NUE, and thereby may contribute to closing the yield gap between attainable and actual yields, especially in dryland and low nutrient input agriculture. The management of soil mulching requires site-specific knowledge.

  8. Interactions of Metarhizium anisoplae and tree-based mulches in repellence and mycoses against Coptotermes formosanus (Isoptera: Rhinotermitidae).

    Science.gov (United States)

    Sun, Jian-Zhong; Fuxa, James R; Richter, Arthur; Ring, Dennis

    2008-06-01

    The use of mulch in urban landscapes has increased in the United States for the past decade. Tree-based organic mulches can supply Coptotermes formosanus Shiraki with food, moisture, and shelter. The current research contributes to mulch management technology in termite control. A choice test arena was designed to determine the repellence and mortality caused by commercial mulches treated with different concentrations of the fungus Metarhizium anisopliae (Metschnikoff) against C. formosanus. Each of six tree-based mulches (pine bark, pine straw, bald cypress, eucalyptus, water oak, and melaleuca) was coated with six conidial concentrations ranging from 1 x 10(3) to 1 x 10(8) conidia/ml. The foragers of C. formosanus were repelled significantly by the fungal-treated mulch substrates; the proportion of termites on fungal-treated mulch was usually 99% of the termites were killed in test arenas containing a chamber with mulch treated with 10(7) or 10(8) conidia/ml. M. anisopliae significantly reduced mulch consumption by 34-71%. Mulch consumption by the termites was negatively correlated with fungal concentration, and the type of mulch also affected consumption. The differences in termite foraging activities, mortality, and food consumption among mulches were usually confounded by differences in fungal concentrations of M. anisopliae. The results indicate that repellence and virulence of M. anisopliae conidia should significantly reduce the suitability of these six mulches as a habitat for C. formosanus. PMID:18559182

  9. Effect of different mulch materials on winter wheat production in desalinized soil in Heilonggang region of North China

    Institute of Scientific and Technical Information of China (English)

    YANG Yan-min; LIU Xiao-jing; LI Wei-qiang; LI Cun-zhen

    2006-01-01

    Freshwater shortage is the main problem in Heilonggang lower-lying plain, while a considerable amount of underground saline water is available. We wanted to find an effective way to use the brackish water in winter wheat production. Surfacemulch has significant effect in reducing evaporation and decreasing soil salinity level. This research was aimed at comparing the effect of different mulch materials on winter wheat production. The experiment was conducted during 2002~2003 and 2003~2004.Four treatments were setup: (1) no mulch, (2) mulch with plastic film, (3) mulch with corn straw, (4) mulch with concrete slab between the rows. The result indicated that concrete mulch and straw mulch was effective in conserving soil water compared to plastic film mulch which increased soil temperature. Concrete mulch decreases surface soil salinity better in comparison to other mulches used. Straw mulch conserved more soil water but decreased wheat grain yield probably due to low temperature. Concrete mulch had similar effect with plastic film mulch on promoting winter wheat development and growth.

  10. Growth and yield of anthurium in response to sawdust mulching

    Directory of Open Access Journals (Sweden)

    Juliana Domingues Lima

    2016-03-01

    Full Text Available ABSTRACT: The objectives of the study were to analyze the effect of sawdust mulch on the: (1 soil characteristics; (2 growth and flower yield of the anthurium cv. 'Apalai'. Assay was conducted in a totally randomized design in subdivided plots, with five treatments and eight replications. The treatment consisted of five volumes of sawdust 0, 20, 40, 60 and 80L m-2, distributed over the bed, every three months. Soil, plants and flower stalks were evaluated during two years. Soil temperature, moisture, organic matter, bulk density and water retention conditions were improved, while the leaf area of plants and the yield of flower stalks were increased when the soil were mulched with sawdust. In addition to increasing soil organic matter, however, no change occurred in the level of nutrients in plants. Sawdust also improved the dimension of flower stalks. Application of 40L m-2 of sawdust every three months is recommended.

  11. Termites and mulch work together to rehabilitate soils

    OpenAIRE

    Ouédraogo, E.; Mando, A.; Brussaard, L.

    2008-01-01

    In semi-arid areas such as the Sahelian zone of Africa, many soils have become severely degraded. One extreme form is the bare and crused soil, which is virtually productively "dead". In Burkina Faso, farmers have responded by applying mulch to attract termites that then help to rehabilitate the soil. A research project shows the importance of termites in breaking up hardened soil and increasing water infiltration. The land became productive enough to farm within months.

  12. Effects of film mulch and unevenness of row surface on soil temperature

    International Nuclear Information System (INIS)

    The purpose of this paper is to clarify the effect of the amount of contact between film mulch and row surface upon the variations of 10 soil temperatures and their deviations at the same 10 cm depth, and thereby properly compare the soil temperatures of two plots. Three process zones, consisting of a zone without mulch, a zone with black polyethylene mulch, and a zone with transparent polyethylene mulch, were established. Each zone was divided into three sub-zones whose contact percentages, that is, the amount of contact between the variations of mulch and the soil, were set to 100%, 70%, and 50%, respectively. Each sub-zone was further divided into two plots: one where no vegetation would be grown, and the other where radish plants would be grown. In all, 18 experimental plots were prepared. The daily range in soil temperature was measured beneath each of the 18 plots. The order relation of the daily ranges among the plots was transparent mulch (1.8 deg C to 2.7 deg C) > no mulch (1.2 deg C to 1.9 deg C) > black mulch (0.8 deg C to 1.1 deg C). The soil temperature order of the two plots based on t-test was as follows: The soil temperature at no mulch zone at 6:00 was 100% plot > 70% plot > 50% plot. The temperature at 15:00 was 50% plot > 70% plot > 100% plot. Accordingly, temperature change in the 50% plot was most significant. Soil temperature in the black mulch zone at 6:00 was highest in the 50% plot. Therefore, the insulating effect at the black mulch zone was the greatest. At 15:00, temperature rise in the 70% plot was most significant. In the transparent mulch zone, the 100% and 70% plots showed an equivalent insulating effect at 6:00, and the temperature rise in the 50% plot at 15:00 was largest. The soil temperature difference between two plots for each mulch zone, the distribution range of the difference between the 100% plot and the 70% plot, and that between the 100% plot and the 50% plot, all increased with increasing amounts of solar radiation. In

  13. Evaluation of mulching materials as integrated weed management component in maize crop

    International Nuclear Information System (INIS)

    Yield losses by weeds in maize crop and demonstrated efficacy of various mulches in weed management led to check the efficacy of various available mulches for suppressing weeds in maize crop at National Agricultural Research Centre (NARC), Islamabad during kharif (autumn) season 2011. The experiment was laid in Randomized Complete Block Design, (RBCD) having eight treatments and four replications. The treatments were black plastic, white plastic, sugarcane straw, wheat straw, live mulch, weeds as mulch, hand weeding and weedy check. Weed data included weed density m, fresh and dry weight g m, while crop data included crop density m, fresh and dry weight g m, number of plant plot, stover yield (g), plant height (cm), number of cobs plant, number of leaves plant, average grain number of five cobs and grain yield (t ha). With the exception of hand weeding, minimum number of weeds 128 m and 164 m were recorded in black plastic and weeds as mulch, respectively, compared to 595 min weedy check. Similarly, maximum grain yields (1.91 and 1.85 tha) were recorded in black plastic and weeds as mulch, while minimum grain yield (0.64 t ha) was recorded in weedy check plots. The economic net returns of black plastic mulch and weeds as mulch were Rs. 39,824 and Rs. 38,291, respectively as compared to Rs. 21431 for weedy check. Yield increased by 21.1 and 16.5% over hand weeding by plastic mulch and weeds as mulch, respectively. Black plastic followed by weeds as mulch, are recommended to control weeds and get maximum yield as well as net economic return. (author)

  14. Yield responses of wheat to mulching practices in dryland farming on the Loess Plateau.

    Directory of Open Access Journals (Sweden)

    Li-fang Wang

    Full Text Available Improving farming practices of soil and water conservation has profound effects on the yield of wheat (Triticum aestivum L. in dryland farming regions of the Loess Plateau in China. Mulching has proven to be an effective practice to increase crop yield, and possibly contribute to replenishing groundwater. This evaluation study collected and analyzed the data of 1849 observations published in 38 papers using meta-analysis to investigate effects of the mulching practices on wheat yield in terms of different rainfall and regions in comparison with conventional tillage. The main results of the study follow. The effects of the mulching practices were ranked in the order of RFM (ridge-furrow mulching > MTMC (mulching with two materials combined > MOM (mulching with other materials > WSM (wheat straw mulching > FM (flat mulching. The effects of the mulching practices at the different levels of rainfall during the wheat growing season were in the order: ( (> 250 mm > (150-250 mm. The effects of the mulching practices in the different regions were in the order of Henan > Shanxi > Shaanxi > Gansu. WSM, MTMC and FM performed better in improving wheat yield for rainfall of 250 mm during the growing season, respectively. The wheat yield with FM, MTMC, MOM and MOM was higher than those with the other mulching practices in Shaanxi, Gansu, Henan and Shanxi. The wheat yield with RFM was 27.4% higher than that with FM, indicating that RFM was the most effective practice to improve wheat yield among all the practices. These findings have important implications for choosing appropriate crop field management to improve wheat yield.

  15. [Relationships of water conservation through mulching in fallow period with wheat nitrogen transportation and crop yield in dryland].

    Science.gov (United States)

    Zhang, Meng; Sun, Min; Gao, Zhi-qiang; Zhao, Hong-mei; Li, Guang; Ren, Ai-xia; Hao, Xing-yu; Yang, Zhen-ping

    2016-01-01

    Field experiments were carried out to study the effects of different mulching times (30 or 60 d after previous wheat harvest) and mulching methods (whole-mulching, half-mulching and no- mulching) on wheat plant N absorption and assimilation after deep plowing in fallow period on dryland. The results showed that mulching improved water storage efficiency in fallow period and soil water storage of 0-300 cm at sowing stage significantly. Mulching in fallow period, especially the whole-mulching, increased the N accumulation amount of each growth stage, N translocation amount and rate before anthesis (NABA) , and N accumulation amount after anthesis (NAAA) and grain N. Yield, N uptake efficiency (NUPE), N partial factor productivity (NPFP) and N harvest index (NHI) were all significantly increased under mulching, and whole-mulching had better effects. Mulching at 30 d after previous wheat harvest significantly increased the soil water storage of 0-300 cm at sowing stage and the water storage efficiency in fallow period compared with mulching at 60 d after previous wheat harvest. Compared with mulching at 60 d after previous wheat harvest, mulching at 30 d increased the N accumulation amount of each growth stage, the N accumulation amount in leaf and shoot at maturity, the NABA of stem + sheath, leaf and shoot and the yield. The soil water at the depth of 0-300 cm at sowing stage was positively correlated to N mobilization amount before anthesis and N accumulation amount after anthesis. The N mobilization amount of stem + sheath had a remarkable direct effect on its yield with the direct path coefficient of 0.619. In summary, mulching in fallow period increased the soil moisture at sowing stage to promote N absorption and utilization, increase yield and improve quality, and whole-mulching in advance had better effects. PMID:27228600

  16. Nematode, Fungi, and Weed Control using Telone C35 and Colored Plastic Mulches

    Science.gov (United States)

    Methyl bromide fumigation controls weeds, fungi, and nematodes. An alternative treatment system was investigated that used various colored plastic mulches with Telone C35 (65% 1,3- dichloropropene plus 35% chloropicrin). These mulches controlled weeds by a thickness that prevented nutsedge penetrati...

  17. The effect of different mulches on the growth and yield of organically grown strawberry

    OpenAIRE

    Kivijärvi, Pirjo; Prokkola, Soile

    2003-01-01

    Different mulches were studied in field trials over a three-year period under organic production in Mikkeli and Ruukki. The mulching materials were black plastic, flax fibre mat (woodchips+buckwheat husk in 2002), green mass, straw, buckwheat husk, birch woodchips and pine woodchips.

  18. The effect of different mulches on yield, fruit quality and strawberry mite in organically grown strawberry

    OpenAIRE

    Kivijärvi, Pirjo; Parikka, Päivi; Tuovinen, Tuomo

    2002-01-01

    An organic strawberry field experiment was started in 2000 at MTT Ecological Production in Mikkeli to study the influence of mulching materials on the growth, yield, microbiological fruit quality and strawberry mite. Mulching materials are black plastic, flax fibre mat, green mass, barley straw, buckwheat husk as well as pine and birch woodchips.

  19. Soil mulching significantly enhances yields and water and nitrogen use efficiencies of maize and wheat

    NARCIS (Netherlands)

    Qin, Wei; Hu, Chunsheng; Oenema, Oene

    2015-01-01

    Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil

  20. A new method to evaluate the weed-suppressing effect of mulches

    DEFF Research Database (Denmark)

    Arentoft, B. W.; Ali, A.; Streibig, Jens Carl;

    2013-01-01

    , with mulch thickness as the independent variable. Weed cover was measured by non-destructive image analysis by estimating the relationship between the number of green pixels and the total number of pixels in each experimental plot. The thickness of mulch layer required to attain a 50 and 90% weed...

  1. A method for estimating maximum static rainfall retention in pebble mulches used for soil moisture conservation

    Science.gov (United States)

    Peng, Hongtao; Lei, Tingwu; Jiang, Zhiyun; Horton, Robert

    2016-06-01

    Mulching of agricultural fields and gardens with pebbles has long been practiced to conserve soil moisture in some semi-arid regions with low precipitation. Rainfall interception by the pebble mulch itself is an important part of the computation of the water balance for the pebble mulched fields and gardens. The mean equivalent diameter (MED) was used to characterize the pebble size. The maximum static rainfall retention in pebble mulch is based on the water penetrating into the pores of pebbles, the water adhering to the outside surfaces of pebbles and the water held between pebbles of the mulch. Equations describing the water penetrating into the pores of pebbles and the water adhering to the outside surface of pebbles are constructed based on the physical properties of water and the pebble characteristics. The model for the water between pebbles of the mulch is based on the basic equation to calculate the water bridge volume and the basic coordination number model. A method to calculate the maximum static rainfall retention in the pebble mulch is presented. Laboratory rain simulation experiments were performed to test the model with measured data. Paired sample t-tests showed no significant differences between the values calculated with the method and the measured data. The model is ready for testing on field mulches.

  2. Vertical Mulching e manejo da água em semeadura direta Vertical Mulching and water management in no tillage system

    Directory of Open Access Journals (Sweden)

    Sandra Maria Garcia

    2008-04-01

    Full Text Available A intensa mobilização do solo no sistema cultivo convencional causou degradação da estrutura, compactação e adensamento do solo abaixo da camada arável, reduzindo a macroporosidade e a taxa de infiltração de água no solo, com conseqüente aumento de escoamento superficial, de erosão e de assoreamento de rios e de reservatórios. A semeadura direta, que protege a superfície do solo, praticamente controlou a perda por erosão hídrica, os terraços foram eliminados, pelos agricultores, e a conseqüência foi maior escoamento superficial do que no sistema cultivo convencional. Com o objetivo de avaliar o comportamento hidrológico do vertical mulching em semeadura direta, em relação ao escoamento superficial, realizou-se esta pesquisa nos anos agrícolas 2002/2003 e 2003/2004, em Latossolo Vermelho distrófico típico, na região fisiográfica do planalto médio do Rio Grande do Sul, isto é, um experimento em escala de campo, com parcelas sem vertical mulching, com vertical mulching a cada 10 m e com vertical mulching a cada 5 m, no delineamento de blocos ao acaso com três repetições. Sulcos em nível, perpendiculares ao declive, com dimensões de 0,08 m de largura por x 0,38 m de profundidade, foram abertos e preenchidos com palha compactada o suficiente para prevenir desmoronamento das paredes do sulco. No ciclo da cultura da soja e do trigo foram simuladas chuvas com duas intensidades, 70 e 106 mm h-1. Foram determinados o escoamento superficial, a taxa de infiltração básica de água no solo e a concentração de nutrientes e de CO no escoamento superficial. Os resultados indicam que o vertical mulching na semeadura direta reduz, significativamente, o volume do escoamento superficial aumenta a taxa de infiltração básica de água no solo e reduz também as perdas totais de nutrientes e de CO devido ao menor volume de água no escoamento superficial.Intensive soil mobilization in the conventional tillage system has caused

  3. Biodegradability of Plastics

    Directory of Open Access Journals (Sweden)

    Yutaka Tokiwa

    2009-08-01

    Full Text Available Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.. In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  4. Effects of Mulching on Soil Properties and Growth of Tea Olive (Osmanthus fragrans).

    Science.gov (United States)

    Ni, Xue; Song, Weiting; Zhang, Huanchao; Yang, Xiulian; Wang, Lianggui

    2016-01-01

    Different mulches have variable effects on soil physical properties and plant growth. This study aimed to compare the effects of mulching with inorganic (round gravel, RG), organic (wood chips, WC), and living (manila turf grass, MG) materials on soil properties at 0-5-cm and 5-10-cm depths, as well as on the growth and physiological features of Osmanthus fragrans L. 'Rixianggui' plants. Soil samples were collected at three different time points from field plots of O. fragrans plants treated with the different mulching treatments. Moisture at both soil depths was significantly higher after mulching with RG and WC than that in the unmulched control (CK) treatment. Mulching did not affect soil bulk density, pH, or total nitrogen content, but consistently improved soil organic matter. The available nitrogen in the soil increased after RG and WC treatments, but decreased after MG treatment during the experimental period. Mulching improved plant growth by increasing root activity, soluble sugar, and chlorophyll a content, as well as by providing suitable moisture conditions and nutrients in the root zone. Plant height and trunk diameter were remarkably increased after mulching, especially with RG and WC. However, while MG improved plant growth at the beginning of the treatment, the 'Rixianggui' plants later showed no improvement in growth. This was probably because MG competed with the plants for water and available nitrogen in the soil. Thus, our findings suggest that RG and WC, but not MG, improved the soil environment and the growth of 'Rixianggui' plants. Considering the effect of mulching on soil properties and plant growth and physiology, round gravel and wood chips appear to be a better choice than manila turf grass in 'Rixianggui' nurseries. Further studies are required to determine the effects of mulch quality and mulch-layer thickness on shoot and root growths. PMID:27508410

  5. Effects of Mulching on Soil Properties and Growth of Tea Olive (Osmanthus fragrans)

    Science.gov (United States)

    Ni, Xue; Song, Weiting; Zhang, Huanchao; Yang, Xiulian; Wang, Lianggui

    2016-01-01

    Different mulches have variable effects on soil physical properties and plant growth. This study aimed to compare the effects of mulching with inorganic (round gravel, RG), organic (wood chips, WC), and living (manila turf grass, MG) materials on soil properties at 0–5-cm and 5–10-cm depths, as well as on the growth and physiological features of Osmanthus fragrans L. ‘Rixianggui’ plants. Soil samples were collected at three different time points from field plots of O. fragrans plants treated with the different mulching treatments. Moisture at both soil depths was significantly higher after mulching with RG and WC than that in the unmulched control (CK) treatment. Mulching did not affect soil bulk density, pH, or total nitrogen content, but consistently improved soil organic matter. The available nitrogen in the soil increased after RG and WC treatments, but decreased after MG treatment during the experimental period. Mulching improved plant growth by increasing root activity, soluble sugar, and chlorophyll a content, as well as by providing suitable moisture conditions and nutrients in the root zone. Plant height and trunk diameter were remarkably increased after mulching, especially with RG and WC. However, while MG improved plant growth at the beginning of the treatment, the ‘Rixianggui’ plants later showed no improvement in growth. This was probably because MG competed with the plants for water and available nitrogen in the soil. Thus, our findings suggest that RG and WC, but not MG, improved the soil environment and the growth of ‘Rixianggui’ plants. Considering the effect of mulching on soil properties and plant growth and physiology, round gravel and wood chips appear to be a better choice than manila turf grass in ‘Rixianggui’ nurseries. Further studies are required to determine the effects of mulch quality and mulch-layer thickness on shoot and root growths. PMID:27508410

  6. Control of enzymatic degradation of biodegradable polymers by treatment with biosurfactants, mannosylerythritol lipids, derived from Pseudozyma spp. yeast strains.

    Science.gov (United States)

    Fukuoka, Tokuma; Shinozaki, Yukiko; Tsuchiya, Wataru; Suzuki, Ken; Watanabe, Takashi; Yamazaki, Toshimasa; Kitamoto, Dai; Kitamoto, Hiroko

    2016-02-01

    Cutinase-like esterase from the yeasts Pseudozyma antarctica (PaE) shows strong degradation activity in an agricultural biodegradable plastic (BP) model of mulch films composed of poly(butylene succinate-co-adipate) (PBSA). P. antarctica is known to abundantly produce a glycolipid biosurfactant, mannosylerythritol lipid (MEL). Here, the effects of MEL on PaE-catalyzed degradation of BPs were investigated. Based on PBSA dispersion solution, the degradation of PBSA particles by PaE was inhibited in the presence of MEL. MEL behavior on BP substrates was monitored by surface plasmon resonance (SPR) using a sensor chip coated with polymer films. The positive SPR signal shift indicated that MEL readily adsorbed and spread onto the surface of a BP film. The amount of BP degradation by PaE was monitored based on the negative SPR signal shift and was decreased 1.7-fold by MEL pretreatment. Furthermore, the shape of PBSA mulch films in PaE-containing solution was maintained with MEL pretreatment, whereas untreated films were almost completely degraded and dissolved. These results suggest that MEL covering the surface of BP film inhibits adsorption of PaE and PaE-catalyzed degradation of BPs. We applied the above results to control the microbial degradation of BP mulch films. MEL pretreatment significantly inhibited BP mulch film degradation by both PaE solution and BP-degradable microorganism. Moreover, the degradation of these films was recovered after removal of the coated MEL by ethanol treatment. These results demonstrate that the biodegradation of BP films can be readily and reversibly controlled by a physical approach using MEL. PMID:26512003

  7. Water fluxes in maize, millet and soybean plant-residue mulches used in direct seeding

    International Nuclear Information System (INIS)

    The objective of this work was to evaluate the effects of crop residue mulches from maize, millet and soybean on water storage capacity, water evaporation, soil cover, solar radiation interception and surface water run-off as well as to incorporate these effects in a crop growth model. The mulch of millet and maize presented higher capacity for water storage than soybean mulch: 3.26, 3.24 and 2.62 g of water per gram of dry matter, respectively. Water losses from wet mulches were related to the potential evapotranspiration. The soil cover levels were similar among the three types of material. The three types of mulch intercepted similar quantities of photosynthetically active radiation and infrared radiation. The mulch of maize straw was slightly more efficient in intercepting radiation than that from millet or soybean. Mulching with millet residues was efficient in the control of surface water run-off: only 45.5 mm of water (out of 843.5 mm rainfall) was lost through runoff under the no-till system with millet as cover crop, whereas 222.5 mm of water was lost in the conventional system with tillage. Most of the relations derived in this work could be described by exponential models. (author)

  8. Biodegradable composites from polyester and sugar beet pulp with antimicrobial coating for food packaging

    Science.gov (United States)

    Totally biodegradable, double-layered antimicrobial composite Sheets were introduced for food packaging. The substrate layers of the sheets were prepared from poly (lactic acid) (PLA) and sugar beet pulp (SBP) or poly (butylene adipate-co-terephthalate (PBAT) and SBP by a twin-screw extruder. The ac...

  9. Microbial Functional Diversity, Biomass and Activity as Affected by Soil Surface Mulching in a Semiarid Farmland.

    Science.gov (United States)

    Shen, Yufang; Chen, Yingying; Li, Shiqing

    2016-01-01

    Mulching is widely used to increase crop yield in semiarid regions in northwestern China, but little is known about the effect of different mulching systems on the microbial properties of the soil, which play an important role in agroecosystemic functioning and nutrient cycling. Based on a 4-year spring maize (Zea mays L.) field experiment at Changwu Agricultural and Ecological Experimental Station, Shaanxi, we evaluated the responses of soil microbial activity and crop to various management systems. The treatments were NMC (no mulching with inorganic N fertilizer), GMC (gravel mulching with inorganic N fertilizer), FMC (plastic-film mulching with inorganic N fertilizer) and FMO (plastic-film mulching with inorganic N fertilizer and organic manure addition). The results showed that the FMO soil had the highest contents of microbial biomass carbon and nitrogen, dehydrogenase activity, microbial activity and Shannon diversity index. The relative use of carbohydrates and amino acids by microbes was highest in the FMO soil, whereas the relative use of polymers, phenolic compounds and amines was highest in the soil in the NMC soil. Compared with the NMC, an increased but no significant trend of biomass production and nitrogen accumulation was observed under the GMC treatment. The FMC and FMO led a greater increase in biomass production than GMC and NMC. Compare with the NMC treatment, FMC increased grain yield, maize biomass and nitrogen accumulation by 62.2, 62.9 and 86.2%, but no significant difference was found between the FMO and FMC treatments. Some soil biological properties, i.e. microbial biomass carbon, microbial biomass nitrogen, being sensitive to the mulching and organic fertilizer, were significant correlated with yield and nitrogen availability. Film mulching over gravel mulching can serve as an effective measure for crop production and nutrient cycling, and plus organic fertilization additions may thus have improvements in the biological quality of the

  10. Runoff Water in Cocoa Plantation as Affected by Rorak Number and Mulch Type

    Directory of Open Access Journals (Sweden)

    Sri Wahyuni

    2015-12-01

    Full Text Available Soil erosion is a serious problem in the field of ecology and environment. Providing rorak (small blocked ditches and mulches as an alternative conservation action is expected to minimize water runoff. The purpose of this study was to examine the effects of combination of rorak and mulches in controlling water runoff in a cocoa farm. Location of this research was in Kaliwining Experimental Station, Indonesian Coffee and Cocoa Research Institute during rainy season in early 2015. This research used a nested design in which there is a complete factorial design of random groups that every combination treatment was repeated three times. Each experiment plot consisted of 16 cocoa trees of eight years old. The first factor was rorak treatment consisted of without rorak, 9 rorak per 16 trees (plot and 16 rorak per 16 trees, whereas the second factor was mulch treatment consisted of control (without mulch, cocoa leaves as mulch and rice straw mixed with cocoa leaves as mulch. Rorak collecting runoff water was made of aluminum with a length of 40 cm, width 30 cm and  high 30 cm. Observation of runoff water was carried out early every morning. The results showed that increased number of rorak combined with cocoa leaf and rice straw significantly controlled runoff water compared to control. Rorak and mulch treatments were able to reduce runoff water compared to control. High number of rorak per plot increased the effectiveness in controlling runoff water when it was combined with mulch especially mixture of wide leaf (cocoa leaf and needleshaped leaf (rice straw. Treatment of 16 rorak in every 16 trees with cocoa leaves and rice straw mulch could reduce runoff water by 82.8% compared to a control.

  11. Microbial Functional Diversity, Biomass and Activity as Affected by Soil Surface Mulching in a Semiarid Farmland

    Science.gov (United States)

    Shen, Yufang; Chen, Yingying; Li, Shiqing

    2016-01-01

    Mulching is widely used to increase crop yield in semiarid regions in northwestern China, but little is known about the effect of different mulching systems on the microbial properties of the soil, which play an important role in agroecosystemic functioning and nutrient cycling. Based on a 4-year spring maize (Zea mays L.) field experiment at Changwu Agricultural and Ecological Experimental Station, Shaanxi, we evaluated the responses of soil microbial activity and crop to various management systems. The treatments were NMC (no mulching with inorganic N fertilizer), GMC (gravel mulching with inorganic N fertilizer), FMC (plastic-film mulching with inorganic N fertilizer) and FMO (plastic-film mulching with inorganic N fertilizer and organic manure addition). The results showed that the FMO soil had the highest contents of microbial biomass carbon and nitrogen, dehydrogenase activity, microbial activity and Shannon diversity index. The relative use of carbohydrates and amino acids by microbes was highest in the FMO soil, whereas the relative use of polymers, phenolic compounds and amines was highest in the soil in the NMC soil. Compared with the NMC, an increased but no significant trend of biomass production and nitrogen accumulation was observed under the GMC treatment. The FMC and FMO led a greater increase in biomass production than GMC and NMC. Compare with the NMC treatment, FMC increased grain yield, maize biomass and nitrogen accumulation by 62.2, 62.9 and 86.2%, but no significant difference was found between the FMO and FMC treatments. Some soil biological properties, i.e. microbial biomass carbon, microbial biomass nitrogen, being sensitive to the mulching and organic fertilizer, were significant correlated with yield and nitrogen availability. Film mulching over gravel mulching can serve as an effective measure for crop production and nutrient cycling, and plus organic fertilization additions may thus have improvements in the biological quality of the

  12. Impact of tillage, plant population and mulches on phenological characters of maize

    International Nuclear Information System (INIS)

    Field experiments were conducted during 2006 and 2007 in Peshawar, using open pollinated maize variety Azam in RCB design having 3 factors viz., tillage, maize populations and mulches with split-split plot arrangements. Tillage levels (zero and conventional) were assigned to the main plots, populations (90000, 60000 and 30000 plants ha/sup -1/) to sub-plots and four types of mulches (weeds mulch, black plastic mulch, white plastic mulch and mungbean as living mulch), a hand weeding and a weedy check were allotted to sub-sub plots, respectively. Data were recorded on days to tasseling, days to silking, days to maturity, leaf area of maize plant-1 (cm/sub 2/) and plant height (cm). Tillage affected leaf area of maize, where zero tillage resulted lower leaf area of 4094 cm/sub 2/ compared to conventional tillage (4722 cm/sub 2/). Different levels of plant populations affected all the physiological parameters. Days to tasseling, silking and maturity were more in higher plant population as compared to medium and lower plant population. Similarly, minimum leaf area plant-1 was recorded in higher plant population (3894 cm/sub 2/) than medium and lower plant population of 4398 and 4932 cm/sub 2/, respectively. Maximum plant height was recorded in hand weeding treatment (173 cm). However, it was statistically at par with black plastic mulch (171 cm), followed by weeds mulch (162 cm) and white plastic mulch (161 cm) as compared to weedy check (152 cm). Based on two years study it is suggested that even if tillage options and plant populations are a part of the weed management program, it should not be used as a sole management tool, as both have a negative impact on the phenological parameters of maize which subsequently affected the final yield and must be integrated and supplemented with other control methods. (author)

  13. Microbial Functional Diversity, Biomass and Activity as Affected by Soil Surface Mulching in a Semiarid Farmland.

    Directory of Open Access Journals (Sweden)

    Yufang Shen

    Full Text Available Mulching is widely used to increase crop yield in semiarid regions in northwestern China, but little is known about the effect of different mulching systems on the microbial properties of the soil, which play an important role in agroecosystemic functioning and nutrient cycling. Based on a 4-year spring maize (Zea mays L. field experiment at Changwu Agricultural and Ecological Experimental Station, Shaanxi, we evaluated the responses of soil microbial activity and crop to various management systems. The treatments were NMC (no mulching with inorganic N fertilizer, GMC (gravel mulching with inorganic N fertilizer, FMC (plastic-film mulching with inorganic N fertilizer and FMO (plastic-film mulching with inorganic N fertilizer and organic manure addition. The results showed that the FMO soil had the highest contents of microbial biomass carbon and nitrogen, dehydrogenase activity, microbial activity and Shannon diversity index. The relative use of carbohydrates and amino acids by microbes was highest in the FMO soil, whereas the relative use of polymers, phenolic compounds and amines was highest in the soil in the NMC soil. Compared with the NMC, an increased but no significant trend of biomass production and nitrogen accumulation was observed under the GMC treatment. The FMC and FMO led a greater increase in biomass production than GMC and NMC. Compare with the NMC treatment, FMC increased grain yield, maize biomass and nitrogen accumulation by 62.2, 62.9 and 86.2%, but no significant difference was found between the FMO and FMC treatments. Some soil biological properties, i.e. microbial biomass carbon, microbial biomass nitrogen, being sensitive to the mulching and organic fertilizer, were significant correlated with yield and nitrogen availability. Film mulching over gravel mulching can serve as an effective measure for crop production and nutrient cycling, and plus organic fertilization additions may thus have improvements in the biological

  14. 华北地区地膜残留及典型覆膜作物残膜系数%Characteristics of residual mulching film and residual coefficient of typical crops in North China

    Institute of Scientific and Technical Information of China (English)

    张丹; 胡万里; 刘宏斌; 杜连凤; 徐钰; 成振华; 孙世友; 王洪媛

    2016-01-01

    film in North China was 1.5×105 t. Vegetables, cotton and peanut field had great contributions to the total amount of residual film in this region, and the amount of residual film was 5.5×104, 3.9×104 and 3.0×104 t, respectively. Three years of residual coefficient test showed that the residual coefficient of peanut and cotton were 9.7% and 14.3%. If the present mulching pattern was carried on, the quantity of residual film in peanut and cotton fields would reach up to 69.1 and 70.4 kg/hm2 in 2021, becoming polluted areas that exceed the national standard of film residue. Although the pollution of residual film was not serious at present, it will become a significant issue if no measure was taken to solve it. It is in urgent need to elevate mulch film standards, develop biodegradable mulch film and enhance mulch film recycling. This study will eventually contribute to promoting effective control and management of residual mulch pollution in North China.%为阐明华北地区残膜污染现状及当年地膜残留系数,2008-2011年采用问卷调查及样方检测方法对华北地区主要作物的地膜残留状况进行系统调查,在此基础上2011-2014年通过定点试验监测方法研究典型覆膜作物(花生、棉花)的地膜残留系数。结果表明:华北地区土壤耕层地膜残留强度分布范围为0.2~82.2 kg/hm2,其平均值为26.8 kg/hm2。区域内不同作物和不同省份间地膜残留强度存在显著差异(P<0.05),花生和棉花地膜残留强度较高,分别为32.0和31.8 kg/hm2;华北地区所有省份中,河北省农田地膜残留强度最高,为36.8 kg/hm2。2011年,华北地区农田地膜残留总量为14.8万t,其中地膜残留总量居前3位的作物是蔬菜(5.5万t)、棉花(3.9万t)、花生(3.0万t),占残膜总量的83.8%。3 a的地膜残留系数定点监测试验结果表明,花生和棉花的地膜残留系数分别为9.7%和14.3%,如果一直沿用目

  15. Grey water biodegradability.

    Science.gov (United States)

    Ghunmi, Lina Abu; Zeeman, Grietje; Fayyad, Manar; van Lier, Jules B

    2011-02-01

    Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different conditions in the biodegradation test. The maximum aerobic and anaerobic biodegradability and conversion rate for the different COD fractions is determined. The results show that, on average, dormitory grey water COD fractions are 28% suspended, 32% colloidal and 40% dissolved. The studied factors incubation time, inoculum addition and temperature are influencing the determined biodegradability. The maximum biodegradability and biodegradation rate differ between different COD fractions, viz. COD(ss), COD(col) and COD(diss). The dissolved COD fraction is characterised by the lowest degradation rate, both for anaerobic and aerobic conditions. The maximum biodegradability for aerobic and anaerobic conditions is 86 and 70% respectively, whereas the first order conversion rate constant, k₂₀, is 0.119 and 0.005 day⁻¹, respectively. The anaerobic and aerobic conversion rates in relation to temperature can be described by the Arrhenius relation, with temperature coefficients of 1.069 and 1.099, respectively. PMID:20658309

  16. Effects of mulch practices on fresh ear yield and yield components of sweet corn

    OpenAIRE

    Burhan KARA; ATAR, Bekir

    2013-01-01

    The experiment was carried out in the vegetation seasons of 2010 and 2011. The main purpose of the study was to determine the effects of mulch practices (a control-unmulched treatment, a plastic mulch treatment, and a straw mulch treatment) on fresh ear yield and some yield-related traits of sweet corn according to 3 sowing dates: 1 April, 15 April, and 1 May, respectively. The main effects of sowing dates were significant for the harvest period, the emerging rate from soil, the fresh ear yie...

  17. GROWING OF THE ORGANIC POTATOES WITH USING OF THE MULCHING MATERIALS

    OpenAIRE

    Dvorak, Petr; Tomasek, Jaroslav; Hamouz, Karel

    2010-01-01

    Mulching which has become more popular lately is an important way of soil protection in the plant production. Mulching massively reduces soil erosion [DÖRING ET AL., 2005], virus vector in seed potatoes [DÖRING ET AL., 2006] and it may also act as a tool for the control of nitrogen losses by immobilization of post-harvest nitrate [DÖRING ET AL., 2005]. Mulch especially reduces water evaporation from soil and helps to maintain stable soil temperature [JI AND UNGER, 2001; KAR AND KUMAR, 20...

  18. Research on the Peanut Leaf Etiolation Prevention and Film Mulching Effect in Hubei Province

    Institute of Scientific and Technical Information of China (English)

    Changbing; YU; Yinshui; LI; Lihua; XIE; Xiaojia; HU; Boshou; LIAO; Fang; CHEN; Xing; LIAO

    2014-01-01

    The possible nutrient problems existing in leaf etiolation,the influence of film mulching on the yield of peanut and benefits of balanced fertilization were analyzed. The results showed that the deficiency of nutrient elements was not main limiting factor in leaf etiolation of peanut in Hong’an. Deep trench,film mulching,liming and organic manure could be used to prevent leaf etiolation. The film mulching could increase the yield of peanut by improving the rate of germination and seedling,the number of branches and full pod,and it was beneficial to playing the effect of balanced fertilization.

  19. The effect of soil mulching with organic mulches, on weed infestation in broccoli and tomato cultivated under polypropylene fibre, and without a cover

    Directory of Open Access Journals (Sweden)

    Kosterna Edyta

    2014-07-01

    Full Text Available An investigation was done on the effect of different types of organic mulches that were applied in form of straw to the soil mulching process, on the weed infestation, number, and fresh mass of weeds in broccoli cv. Milady F1 (Brassica oleracea L. var. italica Plenck and tomato cv. Polfast F1 (Lycopersicon esculentum Mill. grown under polypropylene fibre as a covering, or grown without a covering. The different types of organic straw mulches were: rye (Secale cereale L., corn (Zea mays L., rape (Brassica napus L. subsp. napus, and buckwheat (Fagopyrum esculentum Moench.. All the organic mulches were applied at a dose of 10 t/ha. The effect of the mulches was compared to a control plot which had no mulch. The type of organic mulch applied to the soil mulching process influenced species composition, number, and fresh mass of weeds. This effect could be the result of the properties of the mulch (colour, structure, etc. or the allelopathic effect on the germination and growth of individual weeds species. Irrespective of the investigated factors, 24 and 25 weeds species, respectively, were observed immediately after cover removal and before broccoli and tomato harvest. In the first date of estimation Chenopodium album L., Echinochloa crus-galli (L. P. Beauv., Fallopia convolvulus (L. Á. Löve, Stellaria media (L. Vill., and Viola tricolor L. dominated, however, before the vegetables were harvested Ch. album, V. tricolor, Veronica arvensis L., and E. crus-galli dominated. An application of polypropylene fibre contributed to an increase in the number and fresh mass of weeds in both vegetables in the first date of estimation (after cover removal. During this period, vegetables cannot compete with weeds. It is important to note, though, that before the vegetables were harvested, a decrease was found in the number and fresh mass of weeds in the covered plots. The most efficient weed limiter, both after cover removal and also before the broccoli and

  20. Biodegradable modified Phba systems

    International Nuclear Information System (INIS)

    Compositions as well as production technology of ecologically sound biodegradable multicomponent polymer systems were developed. Our objective was to design some bio plastic based composites with required mechanical properties and biodegradability intended for use as biodegradable packaging. Significant characteristics required for food packaging such as barrier properties (water and oxygen permeability) and influence of γ-radiation on the structure and changes of main characteristics of some modified PHB matrices was evaluated. It was found that barrier properties were plasticizers chemical nature and sterilization with γ-radiation dependent and were comparable with corresponding values of typical polymeric packaging films. Low γ-radiation levels (25 kGy) can be recommended as an effective sterilization method of PHB based packaging materials. Purposely designed bio plastic packaging may provide an alternative to traditional synthetic packaging materials without reducing the comfort of the end-user due to specific qualities of PHB - biodegradability, Biocompatibility and hydrophobic nature

  1. Green and biodegradable electronics

    OpenAIRE

    Mihai Irimia-Vladu; Eric. D. Głowacki; Gundula Voss; Siegfried Bauer; Niyazi Serdar Sariciftci

    2012-01-01

    We live in a world where the lifetime of electronics is becoming shorter, now approaching an average of several months. This poses a growing ecological problem. This brief review will present some of the initial steps taken to address the issue of electronic waste with biodegradable organic electronic materials. Many organic materials have been shown to be biodegradable, safe, and nontoxic, including compounds of natural origin. Additionally, the unique features of such organic materials sugg...

  2. Energy balance and evapotranspiration of melon grown with plastic mulch in the Brazilian semiarid region

    OpenAIRE

    Valéria Peixoto Borges; Bernardo Barbosa da Silva; José Espínola Sobrinho; Rafael da Costa Ferreira; Alexsandra Duarte de Oliveira; José Francismar de Medeiros

    2015-01-01

    Melon plants (Cucumis melo L.) are grown in the state of Rio Grande do Norte (RN), the largest producer of melons in Brazil, with plastic mulch and agrotextiles. Studies of crop evapotranspiration (ET) under these conditions are required to ensure adequate irrigation. This study aimed to determine the crop coefficients (Kc) of irrigated melon plants grown with mulch and agrotextiles in the region of Mossoró, RN, based on the Bowen Ratio Energy Balance (BREB) method. Two experiments were condu...

  3. The effect of different mulches on the growth and yield of organically grown strawberry

    OpenAIRE

    Kivijärvi, P.

    2004-01-01

    Different mulches were studied in field trials over a three-year period under organic production in Mikkeli and Ruukki. The soil type was coarse mineral soil rich in humus. In June 2000, organically produced strawberry plants, cv. Jonsok, were planted in four replicates in double rows, 10 plants/plot, 45 cm apart. The mulching materials were black plastic, flax fibre mat (woodchips+buckwheat husk in 2002), green mass, straw, buckwheat husk, birch woodchips and pine woodchips.

  4. DO LIVING MULCH BASED VEGETABLE CROPPING SYSTEMS YIELD SIMILARLY TO THE SOLE ONES?

    OpenAIRE

    Canali, S.; Campanelli, G.; Bavec, F.; von Fragstein, P.; Leteo, F.; Jocop, M.; Kristensen, H.L.

    2014-01-01

    Ecological services may be exploited by use of living mulches in intercropping systems for production of vegetable crops. But may high yields be attained in intercropping systems for production of resource demanding crops such as cauliflower? In the frame of the InterVeg (Core Organic II) project, four field experiments were carried out in IT, SLO, DE and DK in order to study the effect of the living mulch introduction in cauliflower based cropping systems on crop yield and yield quality. The...

  5. The effect of covering and mulching on the soil temperature, growth and yield of tomato

    OpenAIRE

    Kosterna Edyta

    2014-01-01

    By improving the thermal and moisture conditions in the immediate vicinity of plants, plastic covers influenced the growth and development and increased the yield of vegetables. Soil mulching with organic material is one method of soil water protection and also helps maintain a constant soil temperature within the root system of crops. This study investigated the effect of plant covering and the type of straw applied to soil mulching (rye, corn, rape or buckwheat) on the soil temperature, dev...

  6. Much Improved Water Use Efficiency of Rice under Non-Flooded Mulching Cultivation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Water shortage is increasingly limiting the luxury use of water in rice cultivation. In this study, non-flooded mulching cultivation of rice only consumed a fraction of the water that was needed for traditional flooded cultivation and largely maintained the grain yield. We also investigated the growth and development of rice plants and examined grain yield formation when rice was subjected to non-flooded mulching cultivation. One indica hybrid rice combination was grown in a field experiment and three cultivation methods, traditional flooding (TF), non-flooded straw mulching cultivation (SM) and non-flooded plastic mulching cultivation (PM), were conducted during the whole season. Grain yield showed that there was no significant difference between SM and TF rice, but the grain yield of SM cultivation was significantly higher than that of PM. The tiller numbers were inhibited in the early stage under non-flooded mulching cultivation, but the situation was reversed at the later period. Both SM and PM rice reduced dry matter accumulation of shoot, but increased root dry weight,enhanced the remobilization of assimilates from stems to grains and increased the harvest index. During the middle and later grain filling period, mulched plants showed a faster decrease in chlorophyll concentrations, photosynthetic rates of flag leaves and root activity than TF rice, indicating that non-flooded mulching cultivation enhanced plant senescence. In comparison, SM treatment produced higher grain yield and, more dry matter accumulation and panicle numbers than the PM treatment. The overall results suggest that high yield of non-flooded mulching cultivation of rice can be achieved with much improved irrigational water use efficiency.

  7. Plastic mulching in agriculture. Trading short-term agronomic benefits for long-term soil degradation?

    Science.gov (United States)

    Steinmetz, Zacharias; Wollmann, Claudia; Schaefer, Miriam; Buchmann, Christian; David, Jan; Tröger, Josephine; Muñoz, Katherine; Frör, Oliver; Schaumann, Gabriele Ellen

    2016-04-15

    Plastic mulching has become a globally applied agricultural practice for its instant economic benefits such as higher yields, earlier harvests, improved fruit quality and increased water-use efficiency. However, knowledge of the sustainability of plastic mulching remains vague in terms of both an environmental and agronomic perspective. This review critically discusses the current understanding of the environmental impact of plastic mulch use by linking knowledge of agricultural benefits and research on the life cycle of plastic mulches with direct and indirect implications for long-term soil quality and ecosystem services. Adverse effects may arise from plastic additives, enhanced pesticide runoff and plastic residues likely to fragment into microplastics but remaining chemically intact and accumulating in soil where they can successively sorb agrochemicals. The quantification of microplastics in soil remains challenging due to the lack of appropriate analytical techniques. The cost and effort of recovering and recycling used mulching films may offset the aforementioned benefits in the long term. However, comparative and long-term agronomic assessments have not yet been conducted. Furthermore, plastic mulches have the potential to alter soil quality by shifting the edaphic biocoenosis (e.g. towards mycotoxigenic fungi), accelerate C/N metabolism eventually depleting soil organic matter stocks, increase soil water repellency and favour the release of greenhouse gases. A substantial process understanding of the interactions between the soil microclimate, water supply and biological activity under plastic mulches is still lacking but required to estimate potential risks for long-term soil quality. Currently, farmers mostly base their decision to apply plastic mulches rather on expected short-term benefits than on the consideration of long-term consequences. Future interdisciplinary research should therefore gain a deeper understanding of the incentives for farmers

  8. Effect of drip and surface irrigation on yield, water- use-efficiency and economics of capsicum (c apsicum annum l. Grown under mulch and non mulch conditions in eastern coastal india

    Directory of Open Access Journals (Sweden)

    J.C. Paul

    2013-02-01

    Full Text Available A field experiments was conducted on the loamy sand soil at Bhubaneswar in eastern coastal of India for two years (2007-08 and 2008-09 to evaluate the yield, water-use-efficiency and economic feasibility of capsicum grown under drip and surface irrigation with non-mulch and black Linear Low Density Poly Ethylene (LLDPE plastic mulch. Actual evapotranspiration for capsicum crop was estimated using modified pan evaporation method. The net irrigation volume (V was determined after deducting the effective rainfall. Effect of three irrigation levels viz. VD, 0.8 VD and 0.6 VD (VD = full irrigation volume with drip in conjunction with LLDPE mulch and no mulch were studied on biometric and yield response of capsicum crop. The results of surface irrigation were compared with drip irrigation system under no mulch and in conjunction with LLDPE mulch. The study indicated better plant growth, more number of fruits per plant and enhancement in the yield under drip irrigation system with LLDPE mulch. The highest yield (28.7 t/ha was recorded under 100% net irrigation volume with drip irrigation (VD and plastic mulching as compared to other treatments. This system increased the yield and net seasonal income by 57 % and 54 % respectively as compared to conventional surface irrigation without mulch with a benefit cost ratio of 2.01. The benefit cost ratio was found to be the highest (2.44 for the treatment VD without mulch. Drip irrigation system could increase the yield by 28 % over surface irrigation even in the absence of mulch. Similarly, LLDPE mulch alone could increase the yield by 13 % even in the absence of drip irrigation system.1,2,3 Associate Professor, College of Agricultural Engineering and Technology, Orissa University of Agriculture and Technology, Bhubaneswar, India, plp_ouat@yahoo.co.in4 Professor, College of Agricultural Engineering and Technology, Orissa University of Agriculture and Technology, Bhubaneswar, India, kajal_bp@yahoo.co.in

  9. Effect of drip and surface irrigation on yield, water- use-efficiency and economics of capsicum (c apsicum annum l. Grown under mulch and non mulch conditions in eastern coastal India

    Directory of Open Access Journals (Sweden)

    J.C. Paul

    2013-02-01

    Full Text Available A field experiments was conducted on the loamy sand soil at Bhubaneswar in eastern coastal of India for two years (2007-08 and 2008-09 to evaluate the yield, water-use-efficiency and economic feasibility of capsicum grown under drip and surface irrigation with non-mulch and black Linear Low Density Poly Ethylene (LLDPE plastic mulch. Actual evapotranspiration for capsicum crop was estimated using modified pan evaporation method. The net irrigation volume (V was determined after deducting the effective rainfall. Effect of three irrigation levels viz. VD, 0.8 VD and 0.6 VD (VD = full irrigation volume with drip in conjunction with LLDPE mulch and no mulch were studied on biometric and yield response of capsicum crop. The results of surface irrigation were compared with drip irrigation system under no mulch and in conjunction with LLDPE mulch. The study indicated better plant growth, more number of fruits per plant and enhancement in the yield under drip irrigation system with LLDPE mulch. The highest yield (28.7 t/ha was recorded under 100% net irrigation volume with drip irrigation (VD and plastic mulching as compared to other treatments. This system increased the yield and net seasonal income by 57 % and 54 % respectively as compared to conventional surface irrigation without mulch with a benefit cost ratio of 2.01. The benefit cost ratio was found to be the highest (2.44 for the treatment VD without mulch. Drip irrigation system could increase the yield by 28 % over surface irrigation even in the absence of mulch. Similarly, LLDPE mulch alone could increase the yield by 13 % even in the absence of drip irrigation system.

  10. Water consumption and soil moisture distribution in melon crop with mulching and in a protected environment

    Directory of Open Access Journals (Sweden)

    Rodrigo Otávio Câmara Monteiro

    2013-06-01

    Full Text Available Mulching has become an important technique for land cover, but there are some technical procedures which should be adjusted for these new modified conditions to establish optimum total water depth. It is also important to observe the soil-water relations as soil water distribution and wetted volume dimensions. The objective of the present study was to estimate melon evapotranspiration under mulching in a protected environment and to verify the water spatial distribution around the melon root system in two soil classes. Mulching provided 27 mm water saving by reducing water evaporation. In terms of volume each plant received, on average, the amount of 175.2 L of water in 84 days of cultivation without mulching, while when was used mulching the water requirement was 160.2 L per plant. The use of mulching reduced the soil moisture variability throughout the crop cycle and allowed a greater distribution of soil water that was more intense in the clay soil. The clayey soil provided on average 43 mm more water depth retention in 0.50 m soil deep relative to the sandy loam soil, and reduced 5.6 mm the crop cycle soil moisture variation compared to sandy loam soil.

  11. Effect of Tithonia diversifolia mulch on Atta cephalotes (Hymenoptera: Formicidae) nests.

    Science.gov (United States)

    Rodríguez, Jonathan; Montoya-Lerma, James; Calle, Zoraida

    2015-01-01

    Recent studies have shown an insecticidal effect of Tithonia diversifolia (Hemsl.) Gray (Asterales: Asteraceae) foliage on workers of Atta cephalotes L. and inhibitory effects of this plant on the growth of the symbiotic fungus Leucoagaricus gongylophorus (A. Müler) Singer. To evaluate the potential of T. diversifolia as a biological control treatment of this important pest, we assessed the effect of green manure (mulch) of this plant on natural nests of A. cephalotes, in Cali, Colombia. Three treatments were randomly assigned to 30 nests: 1) green mulch of T. diversifolia, 2) green mulch of Miconia sp., Ruiz & Pav. and 3) unmulched control. Every 2 wk for 6 mo, the surface of the nests was completely covered with leaves. Physical and chemical parameters of nest soil were assessed before the first and after the last application of the mulch. Ant foraging in T. diversifolia-treated nests decreased by 60% after the initial applications of the mulch, while nest surface area decreased by 40%. When the nests covered with T. diversifolia were opened, it was observed that the superficial fungus chambers had been relocated at a greater depth. In addition, microbial activity and soil pH increased by 84% and 12%, respectively, in nests covered with plant residues. In conclusion, the continued use of T. diversifolia mulch reduces foraging activity and negatively affects the internal conditions of the colonies, thereby inducing the ants to relocate the fungus chambers within the nests. PMID:25843585

  12. Effects of stubble and mulching on soil erosion by wind in semi-arid China

    Science.gov (United States)

    Cong, Peifei; Yin, Guanghua; Gu, Jian

    2016-07-01

    Soil erosion is a growing challenge for agricultural production in Northern China. To explore the effect of variation in stubble height and mulching biomass on soil erosion caused by wind, we conducted a field experiment using a quadratic rotation combination design. Results showed that the quantity of straw mulch was the dominant factor affecting soil erosion, and stubble height was of secondary importance. The soil water content in stubble and straw mulching treatments was higher than in a control treatment at 0–20 cm soil, and the tendency in the amount of soil water content was opposite to the amount of wind erosion (r = ‑0.882, n = 10, p soil water content observed in the stubble and mulch treatments at the 15–20 cm depth was higher than the change from 0–5 cm to 5–10 cm. Combined, the influence of a stubble height of 34 cm and mulch quantity of 4260 kg·ha‑1 lowered the amount of erosion to 0.42 t·ha‑1, and increased the corn yield to 11900 kg·ha‑1. We determined that those were the most appropriate levels of stubble height and straw mulch for crop fields in the semi-arid regions of Northern China.

  13. Fertilization and colors of plastic mulch affect biomass and essential oil of sweet-scented geranium.

    Science.gov (United States)

    Silva, Anderson de Carvalho; Blank, Arie Fitzgerald; dos Santos, Wallace Melo; Prata, Paloma Santana; Alves, Péricles Barreto; Arrigoni-Blank, Maria de Fátima

    2014-01-01

    Sweet-scented geranium (Pelargonium graveolens L'Hér), a plant belonging to the Geraniaceae family, has medicinal and aromatic properties and is widely used in the cosmetic, soap, perfume, aromatherapy, and food industries. The aim of this study was to evaluate the influence of fertilization and the use of different colors of plastic mulch on sweet-scented geranium biomass and essential oil. Three colors of plastic mulch (black, white, and silver-colored) and a control without plastic mulch were assessed along with three fertilizers (20,000 L · ha(-1) of cattle manure; 1,000 kg · ha(-1) of NPK 3-12-6; and 20,000 L · ha(-1) of cattle manure + 1,000 kg · ha(-1) of NPK 3-12-6 fertilizer) and a control without fertilizer. The absence of a soil cover negatively influenced the agronomical variables, while coverage with plastic mulch was associated with increased biomass. The use of fertilizer had no effect on the evaluated agronomic variables. When cattle manure and NPK 3-12-6 were used together, combined with white or black plastic mulch, the highest yields of essential oil were obtained. For the silver-colored plastic mulch, higher amounts of essential oil (6,9-guaiadien) were obtained with mineral fertilizer. PMID:24757440

  14. Fertilization and Colors of Plastic Mulch Affect Biomass and Essential Oil of Sweet-Scented Geranium

    Directory of Open Access Journals (Sweden)

    Anderson de Carvalho Silva

    2014-01-01

    Full Text Available Sweet-scented geranium (Pelargonium graveolens L’Hér, a plant belonging to the Geraniaceae family, has medicinal and aromatic properties and is widely used in the cosmetic, soap, perfume, aromatherapy, and food industries. The aim of this study was to evaluate the influence of fertilization and the use of different colors of plastic mulch on sweet-scented geranium biomass and essential oil. Three colors of plastic mulch (black, white, and silver-colored and a control without plastic mulch were assessed along with three fertilizers (20,000 L·ha−1 of cattle manure; 1,000 kg·ha−1 of NPK 3-12-6; and 20,000 L·ha−1 of cattle manure + 1,000 kg·ha−1 of NPK 3-12-6 fertilizer and a control without fertilizer. The absence of a soil cover negatively influenced the agronomical variables, while coverage with plastic mulch was associated with increased biomass. The use of fertilizer had no effect on the evaluated agronomic variables. When cattle manure and NPK 3-12-6 were used together, combined with white or black plastic mulch, the highest yields of essential oil were obtained. For the silver-colored plastic mulch, higher amounts of essential oil (6,9-guaiadien were obtained with mineral fertilizer.

  15. The influence of plant mulches on the content of phenolic compounds in soil and primary weed infestation of maize

    OpenAIRE

    Agnieszka Stokłosa; Tomasz Hura; Ewa Stupnicka-Rodzynkiewicz; Teresa Dąbkowska; Andrzej Lepiarczyk

    2012-01-01

    In growing maize, an increase in the content of phenolic compounds and selected phenolic acids in soil was found after the incorporation of white mustard, buckwheat, spring barley, oats and rye mulches into the soil. The highest content of phenolic compounds in soil was found after oats mulch incorporation (20% more than in the control soil). The highest content of selected phenolic acids was found for the soil with the oats and rye mulch. Among the phenolic acids investigated, ferulic acid w...

  16. THE INCREASE OF SWEET CORN COBS YIELD DUE TO NITROGEN FERTILIZERS AND STRAW MULCHING OF ROW SPACING

    OpenAIRE

    Sidorenko S. E.; Toloraya T. R.; Lomovskoy D. V.

    2015-01-01

    The research about effectiveness of ammonium nitrate with sowing and in phase of corn 5-6 leaves and row spacing cultivation before straw mulching was done in 2011-2013. The scheme of trial included the variants with straw mulching and without it. The variants without fertilizers and with small doses of them on background without mulching gave higher yield of cobs milk maturity then with mulching. But variants with maximum fertilizers (with sowing N30 and in phase of corn 5-6 leaves N30) gave...

  17. Green and biodegradable electronics

    Directory of Open Access Journals (Sweden)

    Mihai Irimia-Vladu

    2012-07-01

    Full Text Available We live in a world where the lifetime of electronics is becoming shorter, now approaching an average of several months. This poses a growing ecological problem. This brief review will present some of the initial steps taken to address the issue of electronic waste with biodegradable organic electronic materials. Many organic materials have been shown to be biodegradable, safe, and nontoxic, including compounds of natural origin. Additionally, the unique features of such organic materials suggest they will be useful in biofunctional electronics; demonstrating functions that would be inaccessible for traditional inorganic compounds. Such materials may lead to fully biodegradable and even biocompatible/biometabolizable electronics for many low-cost applications. This review highlights recent progress in these classes of material, covering substrates and insulators, semiconductors, and finally conductors.

  18. Editorial: Biodegradable Materials

    Directory of Open Access Journals (Sweden)

    Carl Schaschke

    2014-11-01

    Full Text Available This Special Issue “Biodegradable Materials” features research and review papers concerning recent advances on the development, synthesis, testing and characterisation of biomaterials. These biomaterials, derived from natural and renewable sources, offer a potential alternative to existing non-biodegradable materials with application to the food and biomedical industries amongst many others. In this Special Issue, the work is expanded to include the combined use of fillers that can enhance the properties of biomaterials prepared as films. The future application of these biomaterials could have an impact not only at the economic level, but also for the improvement of the environment.

  19. Aphid populations (Hemiptera: Aphidoidea depend of mulching in watermelon production in the Mediterranean region of Croatia

    Directory of Open Access Journals (Sweden)

    K. Zanic

    2013-10-01

    Full Text Available Winged morphs of aphids were investigated under field conditions during 2008, 2010 and 2011 in the Mediterranean region of Croatia. Field experiments were conducted to record aphid diversity and compare polyethylene black mulch to straw mulch and bare soil in terms of their attractiveness to aphid species in a watermelon crop. Aphids were collected weekly using yellow water metal traps from May to July. During the study, 44 species in 31 genera were detected; 36 species in 24 genera were identified in 2008, 18 species in 15 genera were identified in 2010, and 34 species in 25 genera were identified in 2011. The overall seasonal percentage composition showed that Aphis fabae Scopoli and Myzus persicae (Sulzer were consistently eudominant species, whereas Acyrtosiphon pisum (Harris was consistently dominant. Cabbage aphid Brevicoryne brassicae (L. was determined as the dominant species in 2008 and as eudominant species in 2011. Additionally, Macrosiphum rosae (L. was twice recorded as the dominant species, whereas Aphis gossipii Glover was dominant once, and Phorodon humuli (Schrank was eudominant once. Our study also demonstrated that mulching sporadically affected the abundance of individual species. The attractiveness of mulching for aphid species differed between the treatments. It was found that bare soil was attractive to A. pisum and M. rosae, black mulch was attractive to B. helichrysi and P. humuli, and straw mulch was attractive to four aphid species, of which two were eudominant, A. fabae and M. persicae. The presented species are mostly polyphagous, and their preference for certain mulches can be used in crop protection management.

  20. Monitoring Plastic-Mulched Farmland by Landsat-8 OLI Imagery Using Spectral and Textural Features

    Directory of Open Access Journals (Sweden)

    Hasituya

    2016-04-01

    Full Text Available In recent decades, plastic-mulched farmland has expanded rapidly in China as well as in the rest of the world because it results in marked increases of crop production. However, plastic-mulched farmland significantly influences the environment and has so far been inadequately investigated. Accurately monitoring and mapping plastic-mulched farmland is crucial for agricultural production, environmental protection, resource management, and so on. Monitoring plastic-mulched farmland using moderate-resolution remote sensing data is technically challenging because of spatial mixing and spectral confusion with other ground objects. This paper proposed a new scheme that combines spectral and textural features for monitoring the plastic-mulched farmland and evaluates the performance of a Support Vector Machine (SVM classifier with different kernel functions using Landsat-8 Operational Land Imager (OLI imagery. The textural features were extracted from multi-bands OLI data using a Grey Level Co-occurrence Matrix (GLCM algorithm. Then, six combined feature sets were developed for classification. The results indicated that Landsat-8 OLI data are well suitable for monitoring plastic-mulched farmland; the SVM classifier with a linear kernel function is superior both to other kernel functions and to two other widely used supervised classifiers: Maximum Likelihood Classifier (MLC and Minimum Distance Classifier (MDC. For the SVM classifier with a linear kernel function, the highest overall accuracy was derived from combined spectral and textural features in the 90° direction (94.14%, kappa 0.92, followed by the combined spectral and textural features in the 45° (93.84%, kappa 0.92, 135° (93.73%, kappa 0.92, 0° (93.71%, kappa 0.92 directions, and the spectral features alone (93.57%, kappa 0.91. Spectral features make a more significant contribution to monitoring the plastic-mulched farmland; adding textural features from medium resolution imagery provide

  1. Coffee husk mulch on soil erosion and runoff: experiences under rainfall simulation experiment

    Directory of Open Access Journals (Sweden)

    H. Moreno-Ramón

    2014-05-01

    Full Text Available The high erosion rates found in the agriculture land make valuable the use of mulches to control the soil and water losses. Coffee husk (Coffee canephora var. robusta can be one of those mulches. This paper evaluates how to apply the mulch in order to obtain, with the same doses, the best effectiveness. An experimental factorial design 4 × 3 × 2 with two replicates was designed in a greenhouse with a total amount of 48 treatments. All the samples were deposited in trays of 0.51 m2 and applied a simulated rain of 122 mm h−1 during 21 min. The factors examined were: four soil classes; three treatments: buried (B, surface (S and non-residue (C, and the presence (WC or absence (WOC of the soil surface crusting. The coffee husk residue (S and B treatments reduced runoff by 10.2% and 46% respectively, soil losses by 78.3% and 88.7% and sediment concentration by 77% and 84.4%. The infiltration rate increased on average by 104% and 167%, and time to runoff by 1.58 and 2.07 min respectively. The coffee husk mulch (S and B avoided the influence of crust. Coffee husk is an efficient mulch to reduce the soil and water losses.

  2. Measuring and modeling maize evapotranspiration under plastic film-mulching condition

    Science.gov (United States)

    Li, Sien; Kang, Shaozhong; Zhang, Lu; Ortega-Farias, Samuel; Li, Fusheng; Du, Taisheng; Tong, Ling; Wang, Sufen; Ingman, Mark; Guo, Weihua

    2013-10-01

    Plastic film-mulching techniques have been widely used over a variety of agricultural crops for saving water and improving yield. Accurate estimation of crop evapotranspiration (ET) under the film-mulching condition is critical for optimizing crop water management. After taking the mulching effect on soil evaporation (Es) into account, our study adjusted the original Shuttleworth-Wallace model (MSW) in estimating maize ET and Es under the film-mulching condition. Maize ET and Es respectively measured by eddy covariance and micro-lysimeter methods during 2007 and 2008 were used to validate the performance of the Penman-Monteith (PM), the original Shuttleworth-Wallace (SW) and the MSW models in arid northwest China. Results indicate that all three models significantly overestimated ET during the initial crop stage in the both years, which may be due to the underestimation of canopy resistance induced by the Jarvis model for the drought stress in the stage. For the entire experimental period, the SW model overestimated half-hourly maize ET by 17% compared with the eddy covariance method (ETEC) and overestimated daily Es by 241% compared with the micro-lysimeter measurements (EL), while the PM model only underestimated daily maize ET by 6%, and the MSW model only underestimated half-hourly maize ET by 2% and Es by 7% during the whole period. Thus the PM and MSW models significantly improved the accuracy against the original SW model and can be used to estimate ET and Es under the film-mulching condition.

  3. Effect of trash mulch and nitrogen application on the cane yield and quality of sugarcane variety thatta

    International Nuclear Information System (INIS)

    The study was carried out to investigate the effect of trash mulching and nitrogen application on the growth, yield and quality of sugarcane variety Thatta-10 at NSCRI, farm Thatta during 2008-09. The data revealed that the plots received 225 N kg ha-1+ trash mulch showed better results for cane yield, yield components and quality. It was further observed that that the plots with mulching and varying doses of nitrogen application had low weed occurrence as compared to control plots receiving 175 N kg ha-1 + no mulch. Economic analysis data revealed that there could be no additional income from the control treatment, which received low levels of N fertilizer (175 N kg/ha) with no mulching. However, all fertilizer levels with trash mulching proved profitable over control. Moreover, better response was observed at 225 N kg/ha+ trash mulch. It is recommended that 225 N kg ha-1 application with trash mulch was profitable for obtaining maximum production of sugarcane. (author)

  4. Numerical study on transient heat transfer under soil with plastic mulch in agriculture applications using a nonlinear finite element model

    CERN Document Server

    De Castro, Carlos Armando

    2011-01-01

    In this paper is developed a simple mathematical model of transient heat transfer under soil with plastic mulch in order to determine with numerical studies the influence of different plastic mulches on the soil temperature and the evolutions of temperatures at different depths with time. The governing differential equations are solved by a Galerkin Finite Element Model, taking into account the nonlinearities due to radiative heat exchange between the soil surface, the plastic mulch and the atmosphere. The model was validated experimentally giving good approximation of the model to the measured data. Simulations were run with the validated model in order to determine the optimal combination of mulch optical properties to maximize the soil temperature with a Taguchi's analysis, proving that the material most used nowadays in Colombia is not the optimal and giving quantitative results of the properties the optimal mulch must possess.

  5. The Effect of Mulching Technology to Enhance the Diversity of Soil Macroinvertebrates in Sengon-based Agroforestry Systems

    Directory of Open Access Journals (Sweden)

    SUGIYARTO

    2009-07-01

    Full Text Available Soil macroinvertebrate are strongly influenced by environmental factors. The change of agronomic technology may affect their role in maintaining soil fertility and crop production. The aims of this study was to know the effect of technology of mulching to enhance diversity of soil macroinvertebrate in sengon-based agroforestry system. Field experiment was arranged in randomized block design with treatment i.e: with and without organic matter mulching. Sweet potato used as tested intercrop. Collection of soil macroinvertebrate was carried out using a hand sorting and pit-fall trap methods. Result of the study showed that application of maize residue as mulch enhanced diversity index of surface and deep soil macroinvertebrate, i.e: 0.215 and 0.214 (by 44% and 73% respectively compared no mulching. Organic mulching technology can support diversity of beneficial soil macroinvertebrates.

  6. Sweet Potato [Ipomoea batatas (L. Lam] Yield Influenced by Seedlings and Mulching

    Directory of Open Access Journals (Sweden)

    Bruno Novak

    2007-12-01

    Full Text Available Sweet potato [Ipomoea batatas (L. Lam] needs a yearly minimum of three month with air temperatures above 15º C for its growth and development. For the purpose of achieving the highest possible sweet potato yield during a relatively short vegetation period in continental part of Croatia, a trial with differently produced seedlings and polyethylene (PE mulch was set up. A trial was set up to study the production of seedlings from dormant sweet potato root sprouts by standard methods, and the most recent method of seedling production in containers, along with testing black PE-fi lm mulched soil, and uncovered soil. The method of seedlings production had significant effect on the yield. Higher mass of marketable roots was achieved by growing seedling with a substrate lump about the root, as compared to the seedlings produced by traditional procedure. Compared to the uncovered soil, a significantly higher yield of marketable roots was obtained with black PE-film mulch.

  7. Allelopathy of rice: effect of rice mulching on the growth of avena sativa

    International Nuclear Information System (INIS)

    Implementation of suitable weed management practice is a critical step in crop production technology to reduce the competition for water, nutrients, space and light between the economically important crops and weeds. Mechanical, chemical or biological agents are being used by the farmer community to cope with the weed problem but these methods are specific in nature, expensive and detrimental to ecosystem. Allelopathy is a cost-effective and environment friendly approach replacing the previous techniques. Therefore, keeping in view the role of rice mulching in weed management, the present study was designed to manipulate the allelopathic traits of rice for the control of Avena sativa in a field trial during which it was grown in non-mulch and rice mulch regimes of different concentrations. (author)

  8. Soil mulching can mitigate soil water deifciency impacts on rainfed maize production in semiarid environments

    Institute of Scientific and Technical Information of China (English)

    ZHU Lin; LIU Jian-liang; LUO Sha-sha; BU Ling-duo; CHEN Xin-ping; LI Shi-qing

    2015-01-01

    Temporaly irregular rainfal distribution and inefifcient rainwater management create severe constraints on crop production in rainfed semiarid areas. Gravel and plastic iflm mulching are effective methods for improving agricultural productivity and water utilization. However, the effects of these mulching practices on soil water supply and plant water use associated with crop yield are not wel understood. A 3-yr study was conducted to analyze the occurrence and distribution of dry spels in a semiarid region of Northwest China and to evaluate the effects of non-mulching (CK), gravel mulching (GM) and plastic iflm mulching (FM) on the soil water supply, plant water use and maize (Zea mays L.) grain yield. Rainfal analysis showed that dry spels of ≥5 days occurred frequently in each of 3 yr, accounting for 59.9–69.2% of the maize growing periods. The >15-d dry spels during the jointing stage would expose maize plants to particularly severe water stress. Compared with the CK treatment, both the GM and FM treatments markedly increased soil water storage during the early growing season. In general, the total evapotranspiration (ET) was not signiifcantly different among the three treatments, but the mulched treatments signiifcantly increased the ratio of pre- to post-silking ET, which was closely associated with yield improvement. As a result, the grain yield signiifcantly increased by 17.1, 70.3 and 16.7% for the GM treatment and by 28.3, 87.6 and 38.2% for the FM treatment in 2010, 2011 and 2012, respectively, compared with the CK treatment. It’s concluded that both GM and FM are effective strategies for mitigating the impacts of water deifcit and improving maize production in semiarid areas. However, FM is more effective than GM.

  9. Evapotranspiration of grapevine trained to a gable trellis system under netting and black plastic mulching

    OpenAIRE

    Moratiel Yugueros, Ruben; Martínez Cob, A.

    2012-01-01

    The evapotranspiration (ET c) of a table grape vineyard (Vitis vinifera, cv. Red Globe) trained to a gable trellis under netting and black plastic mulching was determined under semiarid conditions in the central Ebro River Valley during 2007 and 2008. The netting was made of high-density polyethylene (pores of 12 mm2) and was placed just above the ground canopy about 2.2 m above soil surface. Black plastic mulching was used to minimize soil evaporation. The surface renewal method was used to ...

  10. Absorbable and biodegradable polymers

    CERN Document Server

    Shalaby, Shalaby W

    2003-01-01

    INTRODUCTION NOTES: Absorbable/Biodegradable Polymers: Technology Evolution. DEVELOPMENT AND APPLICATIONOF NEW SYSTEMS: Segmented Copolyesters with Prolonged Strength Retention Profiles. Polyaxial Crystalline Fiber-Forming Copolyester. Polyethylene Glycol-Based Copolyesters. Cyanoacrylate-Based Systems as Tissue Adhesives. Chitosan-Based Systems. Hyaluronic Acid-Based Systems. DEVELOPMENTS IN PREPARATIVE, PROCESSING, AND EVALUATION METHODS: New Approaches to the Synthesis of Crystalline. Fiber-Forming Aliphatic Copolyesters. Advances in Morphological Development to Tailor the Performance of Me

  11. Predicting deep percolation with eddy covariance under mulch drip irrigation

    Science.gov (United States)

    Ming, Guanghui; Tian, Fuqiang; Hu, Hongchang

    2016-04-01

    Water is essential for the agricultural development and ecological sustainability of the arid and semi-arid oasis with rare precipitation input and high evaporation demand. Deep percolation (DP) defined as excess irrigation water percolating below the plant root zone will reduce irrigation water use efficiency (WUE). But the DP was often ignored in mulch drip irrigation (MDI) which has reached the area of 1.6 million hectares in Xinjiang, the northwest of China. In this study DP experiments were conducted at an agricultural experiment station located within an irrigation district in the Tarim River Basin for four cotton growing periods. First it was detected the irrigation water infiltrated into the soil layers below 100cm and the groundwater level responded to the irrigation events well. Then DP below 100cm soil layers was calculated using the soil water balance method with the aid of eddy covariance (with the energy balance closure of 0.72). The negative DP (groundwater contribution to the crop-water use through capillary rising) at the seedling and harvesting stages can reach 77mm and has a good negative correlation with the groundwater level and positive correlation with potential evaporation. During the drip irrigation stage approximately 45% of the irrigation became DP and resulted in the low irrigation WUE of 0.6. The DP can be 164mm to 270mm per year which was positive linearly correlated to irrigation depth and negative linear correlated to irrigation interval. It is better to establish the irrigation schedule with small irrigation depth and given frequently to reduce deep percolation and meet crop needs.

  12. Development of cork oak (Quercus suber L.) seedlings in response to tree shelters and mulching in northwestern Tunisia

    Institute of Scientific and Technical Information of China (English)

    Taher Mechergui; Marta Pardos; Naceur Boussaidi; Brahim Hasnaoui; Douglass F.Jacobs

    2013-01-01

    The need for reforestation in cork oak (Quercus suber L.)areas is challenged by difficulties.Principal among these is herbivory of young plants,vegetative competition,and slow growth rates of cork oak seedlings.We evaluated the early development of cork oak seedlings treated using tree shelters and mulching in northwestern Tunisia.We tested three tree shelter treatments (non-vented,vented,and control) to shield seedlings from animal damage and five mulch types to control competing vegetation (Italian Stone Pine,Lentisk,combination of Italian Stone Pine and Lentisk (organic mulches),gravel (inorganic mulch) and no mulch).At the end of the two-year experiment,sheltered seedlings were 89-99% taller than unsheltered seedlings and had higher numbers and lengths of shoot growth flushes.In contrast,both stem diameter growth and dry weight biomass (from samples extracted after two years)were significantly reduced inside tree shelters.Root-to-shoot ratio was not significantly different in sheltered vs.unsheltered seedlings,suggesting that tree shelters do not adversely affect this parameter.Mulching alone did not favour growth,but could be beneficial when combined with tree shelters.The combination of vented tree shelters and gravel mulch was the most effective treatment for promoting diameter,height and stem volume growth.

  13. The influence of plant mulches on the content of phenolic compounds in soil and primary weed infestation of maize

    Directory of Open Access Journals (Sweden)

    Agnieszka Stokłosa

    2012-12-01

    Full Text Available In growing maize, an increase in the content of phenolic compounds and selected phenolic acids in soil was found after the incorporation of white mustard, buckwheat, spring barley, oats and rye mulches into the soil. The highest content of phenolic compounds in soil was found after oats mulch incorporation (20% more than in the control soil. The highest content of selected phenolic acids was found for the soil with the oats and rye mulch. Among the phenolic acids investigated, ferulic acid was most commonly found in the soil with the plant mulches. However, two phenolic acids: the protocatechuic and chlorogenic acid, were not detected in any soil samples (neither in the control soil nor in the mulched soil. At the same time, a decrease in the primary weed infestation level in maize was found in the plots with all the applied plant mulches, especially on the plots with oats, barley and mustard. The plant mulches were more inhibitory against monocotyledonous weeds than dicotyledonous ones. During high precipitation events and wet weather, a rapid decrease in the content of phenolic compounds in soil and an increase in the primary weed infestation level in maize were observed.

  14. THE INCREASE OF SWEET CORN COBS YIELD DUE TO NITROGEN FERTILIZERS AND STRAW MULCHING OF ROW SPACING

    Directory of Open Access Journals (Sweden)

    Sidorenko S. E.

    2015-04-01

    Full Text Available The research about effectiveness of ammonium nitrate with sowing and in phase of corn 5-6 leaves and row spacing cultivation before straw mulching was done in 2011-2013. The scheme of trial included the variants with straw mulching and without it. The variants without fertilizers and with small doses of them on background without mulching gave higher yield of cobs milk maturity then with mulching. But variants with maximum fertilizers (with sowing N30 and in phase of corn 5-6 leaves N30 gave maximum yield of cobs milk maturity 16,4 t/ha that is higher then similar variant without mulching for 1,7 t/ha. These results were confirmed by analysis of characters of growth and development of corn plants, productivity, and economic effectiveness. Therefore, net profit on variant with fertilizers with sowing N30 and additional fertilizing N30 on background of straw mulching increased for 75490 rubles for 1 ha in comparison with similar variant without mulching. The profitability on the best variant was 335 %

  15. Effect of pine-bark mulch on lowbush blueberry (Vaccinium angustifolium) water demand

    Science.gov (United States)

    Lowbush blueberry (Vaccinium angustifolium) growers seeking an alternative and/or a complement to supplemental irrigation require accurate crop-specific information on the water conserving benefits of mulch. Twenty-eight weighing lysimeters equipped with soil moisture monitors were used at 5 sites ...

  16. Plastic Mulches and Row Covers on the grow and production of Summer Squash.

    Science.gov (United States)

    Summer squash [Cucurbita pepo (L) ‘Prelude II’] was grown on an Orangeburg sandy loam soil in Shorter, AL. The summer squash was direct seeded in single rows. The experiment consisted of twelve experimental treatments as follows: (1) Black plastic mulch (BPM) + spunbonded row cover (RC), (2) BPM, (...

  17. The effects of color plastic mulches and row covers on the growth and yield of okra

    Science.gov (United States)

    Okra [Abelmoschus esculentus (l.) Moench'Clemson Spineless'] was grown on an Orangeburg sandy loam soil in shorter, AL. Okra was direct seeded in single rows. The experiment consisted of twelve experimental treatments as follows: (1) Black plastic mulch (BPM) + spunbonded row cover (RC), (2) BPM, (3...

  18. Cover crops and organic mulches for nematode, weed, and plant health management

    Science.gov (United States)

    Two field experiments were conducted in 2003 and 2004 to evaluate ‘Tropic Sun’ sunn hemp (Crotalaria juncea) and ‘Iron Clay’ cowpea (Vigna unguiculata) as summer cover crops and as organic mulches. Both experiments were a 3 x 3 split-plot design in which the main plots were summer planting of sunn h...

  19. Parboiled rice hull mulch in containers reduces liverwort and bittercress growth

    Science.gov (United States)

    Use of preemergence herbicides for weed control is not always possible; some crops and many enclosed production sites are not labeled for herbicide applications. The objective of this research was to determine the utility of parboiled rice hull mulch for controlling two of the most common weeds in ...

  20. Water Balance and Nitrate Leaching for Corn in Kura Clover Living Mulch

    Science.gov (United States)

    Cropping systems with improved environmental performance are needed in the Midwestern United States. Corn (Zea mays L.) grown in kura clover (Trifolium ambiguum M. Bieb.) living mulch is a relatively new cropping system which may have potential to meet that need. Our objectives were to determine the...

  1. Integrated double mulching practices optimizes soil temperature and improves soil water utilization in arid environments

    Science.gov (United States)

    Yin, Wen; Feng, Fuxue; Zhao, Cai; Yu, Aizhong; Hu, Falong; Chai, Qiang; Gan, Yantai; Guo, Yao

    2016-01-01

    Water shortage threatens agricultural sustainability in many arid and semiarid areas of the world. It is unknown whether improved water conservation practices can be developed to alleviate this issue while increasing crop productivity. In this study, we developed a "double mulching" system, i.e., plastic film coupled with straw mulch, integrated together with intensified strip intercropping. We determined (i) the responses of soil evaporation and moisture conservation to the integrated double mulching system and (ii) the change of soil temperature during key plant growth stages under the integrated systems. Experiments were carried out in northwest China in 2009 to 2011. Results show that wheat-maize strip intercropping in combination with plastic film and straw covering on the soil surface increased soil moisture (mm) by an average of 3.8 % before sowing, 5.3 % during the wheat and maize co-growth period, 4.4 % after wheat harvest, and 4.9 % after maize harvest, compared to conventional practice (control). The double mulching decreased total evapotranspiration of the two intercrops by an average of 4.6 % (P system decreased soil temperature in the top 10-cm depth by 1.26 to 1.31 °C in the strips of the cool-season wheat, and by 1.31 to 1.51 °C in the strips of the warm-season maize through the 2 years. Soil temperature of maize strips higher as 1.25 to 1.94 °C than that of wheat strips in the top 10-cm soil depth under intercropping with the double mulching system; especially higher as 1.58 to 2.11 °C under intercropping with the conventional tillage; this allows the two intercrops to grow in a well "collaborative" status under the double mulching system during their co-growth period. The improvement of soil moisture and the optimization of soil temperature for the two intercrops allow us to conclude that wheat-maize intensification with the double mulching system can be used as an effective farming model in alleviating water shortage issues experiencing in

  2. Buried straw layer and plastic mulching increase microlfora diversity in salinized soil

    Institute of Scientific and Technical Information of China (English)

    LI Yu-yi; PANG Huan-cheng; HAN Xiu-fang; YAN Shou-wei; ZHAO Yong-gan; WANG Jing; ZHAI Zhen; ZHANG Jian-li

    2016-01-01

    Salt stress has been increasingly constraining crop productivity in arid lands of the world. In our recent study, salt stress was aleviated and crop productivity was improved remarkably by straw layer burial plus plastic iflm mulching in a saline soil. However, its impact on the microlfora diversity is not wel documented. Field micro-plot experiments were conducted from 2010 to 2011 using four tilage methods: (i) deep tilage with plastic iflm mulching (CK), (i) straw layer burial at 40 cm (S), (ii) straw layer burial plus surface soil mulching with straw material (S+S), and (iv) plastic iflm mulching plus buried straw layer (P+S). Culturable microbes and predominant bacterial communities were studied; based on 16S rDNA, bacterial com-munity structure and abundance were characterized using denaturing gradient gel electrophoresis (DGGE) and polymerase chain reaction (PCR). Results showed that P+S was the most favorable for culturable bacteria, actinomyces and fungi and induced the most diverse genera of bacteria compared to other tilage methods. Soil temperature had signiifcant positive correlations with the number of bacteria, actinomyces and fungi (P<0.01). However, soil water was poorly correlated with any of the microbes. Salt content had a signiifcant negative correlation with the number of microbers, especialy for bacteria and fungi (P<0.01). DGGE analysis showed that the P+S exhibited the highest diversity of bacteria with 20 visible bands folowed by S+S, S and CK. Moreover, P+S had the highest similarity (68%) of bacterial communities with CK. The major bacterial genera in al soil samples wereFirmicutes,Proteobacteria andActinobacteria. Given the considerable increase in microbial growth, the combined use of straw layer burial and plastic iflm mulching could be a practical option for aleviating salt stress effects on soil microbial community and thereby improving crop production in arid saline soils.

  3. EFFECT OF POLYETHYLENE BLACK PLASTIC MULCH ON GROWTH AND YIELD OF TWO SUMMER VEGETABLE CROPS UNDER RAIN-FED CONDITIONS UNDER SEMI-ARID REGION CONDITIONS

    Directory of Open Access Journals (Sweden)

    Atif Y. Mahadeen

    2014-01-01

    Full Text Available Water use efficiency in agriculture can be enhanced by several strategies mainly by reducing evaporation from the soil surface. The mulching techniques were being used widely in irrigated crop production worldwide. The mulching techniques can be also implemented in summer vegetables production under rain-fed conditions. The current study aimed at evaluating the effect of polyethylene black plastic mulch on growth and yield of okra, Abelmoschus esculentus and summer squash, Cucurbita pepo L. under rain-fed conditions of Jordan. Two field experiments were conducted during summer growing season at Al-Rabbah Agricultural Research Station, Mu’tah University, Jordan. Soil cover treatments were polyethylene black plastic mulch and no mulch (bare soil. The results indicated that the mulched plots had higher soil moisture content than bare soil plots, which has positively reflected on vegetative and yield parameters. Using polyethylene plastic mulch had pronounced positive effect on yield of okra and squash as compared to bare soil. Early, middle, late and total yield of both vegetable crops were significantly increased in plots covered with plastic mulch. In addition, fruit number and weight had also an increasing trend as fruit yield. Plots covered with black plastic mulch were produced higher fresh and dry weights of both vegetable crops. It ban be concluded that using black plastic mulch as a soil cover increased okra and squash vegetative growth and yield under rain-fed conditions.

  4. Preparation of a biodegradable oil absorber and its biodegradation.

    Science.gov (United States)

    Yoo, Su-Yong; Daud, Wan Mohd Ashri Wan; Lee, Min-Gyu

    2012-01-01

    The biodegradable oil absorption resin (B-PEHA) was prepared by suspension polymerization, and its preparation was confirmed by Fourier transform infrared analysis. The oil absorption capacities of the prepared B-PEHA were: chloroform 30.88, toluene 19.75, xylene, 18.78, THF 15.96, octane 11.43, hexane 9.5, diesel oil 12.80, and kerosene 13.79 g/g. The biodegradation of the prepared B-PEHA was also investigated by determination of reduced sugar produced after enzymatic hydrolysis, thermogravimetric analysis, and incubation with Aspergillus niger. The biodegradation of B-PEHA was ~18%. PMID:21909668

  5. Effect of different mulch materials on winter wheat production in desalinized soil in Heilonggang region of North China*

    OpenAIRE

    Yang, Yan-min; Liu, Xiao-Jing; Li, Wei-Qiang; Li, Cun-zhen

    2006-01-01

    Freshwater shortage is the main problem in Heilonggang lower-lying plain, while a considerable amount of underground saline water is available. We wanted to find an effective way to use the brackish water in winter wheat production. Surface mulch has significant effect in reducing evaporation and decreasing soil salinity level. This research was aimed at comparing the effect of different mulch materials on winter wheat production. The experiment was conducted during 2002~2003 and 2003~2004. F...

  6. Biodegradation of Polypropylene Nonwovens

    Science.gov (United States)

    Keene, Brandi Nechelle

    The primary aim of the current research is to document the biodegradation of polypropylene nonwovens and filament under composting environments. To accelerate the biodegradat ion, pre-treatments and additives were incorporated into polypropylene filaments and nonwovens. The initial phase (Chapter 2) of the project studied the biodegradation of untreated polypropylene with/without pro-oxidants in two types of composting systems. Normal composting, which involved incubation of samples in food waste, had little effect on the mechanical properties of additive-free spunbond nonwovens in to comparison prooxidant containing spunbond nonwovens which were affected significantly. Modified composting which includes the burial of samples with food and compressed air, the polypropylene spunbond nonwovens with/without pro-oxidants displayed an extreme loss in mechanical properties and cracking on the surface cracking. Because the untreated spunbond nonwovens did not completely decompose, the next phase of the project examined the pre-treatment of gamma-irradiation or thermal aging prior to composting. After exposure to gamma-irradiation and thermal aging, polypropylene is subjected to oxidative degradation in the presence of air and during storage after irradiat ion. Similar to photo-oxidation, the mechanism of gamma radiation and thermal oxidative degradation is fundamentally free radical in nature. In Chapter 3, the compostability of thermal aged spunbond polypropylene nonwovens with/without pro-oxidant additives. The FTIR spectrum confirmed oxidat ion of the polypropylene nonwovens with/without additives. Cracking on both the pro-oxidant and control spunbond nonwovens was showed by SEM imaging. Spunbond polypropylene nonwovens with/without pro-oxidants were also preirradiated by gamma rays followed by composting. Nonwovens with/without pro-oxidants were severely degraded by gamma-irradiation after up to 20 kGy exposure as explained in Chapter 4. Furthermore (Chapter 5), gamma

  7. Effects of Tillage and Mulch Methods on Soil Moisture in Wheat Fields of Loess Plateau,China

    Institute of Scientific and Technical Information of China (English)

    GAOZHIQIANG; YINJUN; 等

    1999-01-01

    Effects of different methods of tillage and mulch on soil moisture at fallow stage were studied in rainy and rain-deficient years.Soil moisture content per 20 cm was measured vertically within 0-300 cm soil layers in an experiment with five treatments:deep-loosening tillage(DLT),traditional tillage(TT),plastic mulch(PM),straw mulch(SM) and plastic plus straw mulch(PSM),All mulch treatments were under no tillage conditions.Total storage of precipitation in soil from 0 to 300cm was determined before sowing,Results showed that the new methods of tillage and mulch were the basic ways to improve water condition in dryland wheat fields.In a rainy year,PM with no tillage played a significant role in storing and conserving precipitation.while in a rain-deficient year,the role was not significant,Due to evaporation.DLT did not promote the storage of soil moisture,SM was the best way to store and conserve soil moisture,In SM treatment the wheat yields increased by more than 20%.

  8. Effects of organic amendments and mulches on soil microbial communities in quarry restoration under semiarid climate

    Science.gov (United States)

    Luna Ramos, Lourdes; Pastorelli, Roberta; Miralles Mellado, Isabel; Fabiani, Arturo; Bastida López, Felipe; Hernández Fernández, María Teresa; García Izquierdo, Carlos; Solé Benet, Albert

    2015-04-01

    Mining activities generate loss of the quality of the environment and landscape specially in arid and semiarid Mediterranean regions. A precondition for ecosystem reclamation in such highly disturbed mining areas is the development of functional soils with appropriate levels of organic matter. In an experimental soil restoration in limestone quarries from Sierra de Gádor (Almería), SE Spain, 9 plots 15 x 5 m were prepared to test organic amendments (compost from solid urban residues-DOW-, sludge from urban water treatment-SS-, control-NA-) and different mulches (fine gravel-GM-, wood chips-WM-, control-NM-) with the aim to improve soil/substrate properties and to reduce evaporation and erosion. In each experimental plot, 75 native plants (Macrochloa tenacissima, Anthyllis terniflora and Anthyllis cytisoides) were planted. After 5 years from the start of the experiment, we evaluated how microbial community composition responded to the organic amendments and mulches. Microbial community composition of both bacteria and fungi was determined by phospholipid fatty acid (PLFA) and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprinting. The results of the two-way ANOVA showed that PLFAs were significantly affected by organic amendments but not by the mulches or interaction of both factors. Experimental plots with DOW showed significantly higher level of fungal PLFAs than those with SS and NA, even higher than the reference undisturbed soil. However, any plot with organic amendments did not reach the content of bacterial PLFAs of the reference soils. The bacterial diversity (evaluated by diversity indices calculated from DGGE profiles) was greater in soil samples taken under NA and GM. Comparing these indices in fungal DGGE, we found greater values for soil samples taken under DOW and without mulches. Results from UPGMA analysis showed significant differences in the structure of soil bacterial communities from the different treatments

  9. Changes in soil parameters under continuous plastic mulching in strawberry cultivation

    Science.gov (United States)

    Muñoz, Katherine; Diehl, Dörte; Scopchanova, Sirma; Schaumann, Gabriele E.

    2016-04-01

    Plastic mulching (PM) is a widely used practice in modern agriculture because they generate conditions for optimal yield rates and quality. However, information about long-term effects of PC on soil quality parameters is scarce. The aim of this study is to compare the effect of three different mulching managements on soil quality parameters. Sampling and methodology: Three different managements were studied: Organic mulching (OM), 2-years PM and 4-years PM. Soil samples were collected from irrigated fields in 0-5, 5-10 and 10-30 cm depths and analyzed for water content (WC), pH, dissolved organic carbon (DOC), total soil carbon (Ctot) and cation exchange capacity (CECeff). Results and discussion: Mulching management has an influence on soil parameters. The magnitude of the effects is influenced by the type (organic agriculture practice vs. plastic mulching practice) and duration of the mulching. PM modified the water distribution through the soil column. WC values at the root zone were in average 10% higher compared to those measured at the topsoil. Under OM, the WC was lower than under PM. The pH was mainly influenced by the duration of the managements with slightly higher values after 4 than after 2-years PM. Under PM, aqueous extracts of the topsoil (0-5 cm depth) contained in average with 8.5±1.8 mg/L higher DOC than in 10-30 cm depth with 5.6±0.5 mg/L, which may indicate a mobilization of organic components in the upper layers. After 4-years PM, Ctot values were slightly higher than after 2-years PM and after OM. Surprisingly, after 4-years PM, CECeff values were with 138 - 157 mmolc/kg almost 2-fold higher than after 2-years PM and OM which had with 74 - 102 mmolc/kg comparable CECeff values. Long-term PM resulted in changes of soil pH and slightly increased Ctot which probably enhanced the CECeff of the soil. However, further investigations of the effect of PM on stability of soil organic matter and microbial community structure are needed.

  10. Chemical Elements in Mulch and Litterfall of Beech Ecosystems and Their Total Turnover

    Directory of Open Access Journals (Sweden)

    Mariyana I. Lyubenovа

    2011-07-01

    Full Text Available The beech communities on the territory of Bulgaria had been objects of regional, local as well as large scale national investigations aiming their classification, determination of their ecological characteristics, conservation status, habitats etc. They are included as objects of the intensive monitoring of forest ecosystems in Bulgaria also. The investigations of chemical content of the litter – fall in these forests were conducted until now. The novelty of the present research is investigation of these elements in the mulch and the ratio between the established quantities calculation. The main goal is the biological turnover special features characterization of the investigated elements which give us a chance to define the investigated ecosystems state and functioning. The indexes as litter – mulch and acropetal coefficients were used for this aim. The content of macroelements as N, Ca and K and microelements as Pb, Zn, Mn and Fe in soils, mulch and in different litter fall fractions have been calculated. The investigation was carried out on three sample plots. During the investigation was established that the soils are characterized with acid reaction, high content of Fe, N and Mn and low content of Ca and K. The concentration of Zn and Pb are high also. The calculated average store of investigated elements in litter – fall is 81.312 kg.ha1 and in the mulch 314 kg.ha1. According to the acropetal coefficient N is accumulated mainly in the acorns, K – in the annual phytomass fractions and Ca – in the perennial fractions. The leaves and the acorns fraction accumulate Mn, and cupolas Fe. The litter – mulch coefficient vary from 1,6 (Mn to 4,2 (Pb. The tendencies of Zn and Ca turnovers acceleration are discovered, while the turnover of more investigated elements is inhibited. The litter – mulch coefficient for Zn and Ca is 0,8 and 1,4 accordingly, i.е. corresponding to the intensive type of turnovers which is not typical for the

  11. Biodegradable micromechanical sensors

    DEFF Research Database (Denmark)

    Keller, Stephan Sylvest; Greve, Anders; Schmid, Silvan;

    The development of biopolymers for food packaging, medical engineering or drug delivery is a growing field of research [1]. At the same time, the interest in methods for detailed analysis of biopolymers is increasing. Micromechanical sensors are versatile tools for the characterization of mechani......The development of biopolymers for food packaging, medical engineering or drug delivery is a growing field of research [1]. At the same time, the interest in methods for detailed analysis of biopolymers is increasing. Micromechanical sensors are versatile tools for the characterization...... of biopolymers to microfabrication is challenging, as these polymers are affected by common processes such as photolithography or wet etching. Here, we present two methods for fabrication of biodegradable micromechanical sensors. First, we fabricated bulk biopolymer microcantilevers using nanoimprint lithography...

  12. Biodegradation of biodiesel fuels

    International Nuclear Information System (INIS)

    Biodiesel fuel test substances Rape Ethyl Ester (REE), Rape Methyl Ester (RME), Neat Rape Oil (NR), Say Methyl Ester (SME), Soy Ethyl Ester (SEE), Neat Soy Oil (NS), and proportionate combinations of RME/diesel and REE/diesel were studied to test the biodegradability of the test substances in an aerobic aquatic environment using the EPA 560/6-82-003 Shake Flask Test Method. A concurrent analysis of Phillips D-2 Reference Diesel was also performed for comparison with a conventional fuel. The highest rates of percent CO2 evolution were seen in the esterified fuels, although no significant difference was noted between them. Ranges of percent CO2 evolution for esterified fuels were from 77% to 91%. The neat rape and neat soy oils exhibited 70% to 78% CO2 evolution. These rates were all significantly higher than those of the Phillips D-2 reference fuel which evolved from 7% to 26% of the organic carbon to CO2. The test substances were examined for BOD5 and COD values as a relative measure of biodegradability. Water Accommodated Fraction (WAF) was experimentally derived and BOD5 and COD analyses were carried out with a diluted concentration at or below the WAF. The results of analysis at WAF were then converted to pure substance values. The pure substance BOD5 and COD values for test substances were then compared to a control substance, Phillips D-2 Reference fuel. No significant difference was noted for COD values between test substances and the control fuel. (p > 0.20). The D-2 control substance was significantly lower than all test substances for BCD, values at p 5 value

  13. The effects of mulching on soil erosion by water. A review based on published data

    Science.gov (United States)

    Prosdocimi, Massimo; Jordán, Antonio; Tarolli, Paolo; Cerdà, Artemi

    2016-04-01

    Among the soil conservation practices that have been recently implemented, mulching has been successfully applied in different contexts (Jordán et al., 2011), such as agricultural lands (García-Orenes et al. 2009; Prosdocimi et al., 2016), fire-affected areas (Prats et al., 2014; Robichaud et al., 2013) and anthropic sites (Hayes et al., 2005), to reduce water and soil losses rates. In these contexts, soil erosion by water is a serious problem, especially in semi-arid and semi-humid areas of the world (Cerdà et al., 2009; Cerdan et al., 2010; Sadeghi et al., 2015). Although soil erosion by water consists of physical processes that vary significantly in severity and frequency according to when and where they occur, they are also strongly influenced by anthropic factors such as unsustainable farming practices and land-use changes on large scales (Cerdà, 1994; Montgomery, 2007). Although the beneficial effects of mulching are known, their quantification needs further research, especially in those areas where soil erosion by water represents a severe threat. In literature, there are still some uncertainties about how to maximize the effectiveness of mulching in the reduction of soil and water loss rates. First, the type of choice of the vegetative residues is fundamental and drives the application rate, cost, and consequently, its effectiveness. Second, it is important to assess application rates suitable for site-specific soil and environment conditions. The percentage of area covered by mulch is another important aspect to take into account, because it has proven to influence the reduction of soil loss. And third, the role played by mulching at catchment scale, where it plays a key role as barrier for breaking sediment and runoff connectivity. Given the seriousness of soil erosion by water and the uncertainties that still concern the correct use of mulching, this work aims to evaluate the effects of mulching on soil erosion rates and water losses in agricultural

  14. FOSSIL FUEL BIODEGRADATION: LABORATORY STUDIES

    Science.gov (United States)

    Natural processes of biodegradation, that return carbon from its various organic forms to the inorganic state, are increasingly screened for bioremediation applications. ariety of microbial systems capable of degrading synthetic organic chemicals, from pesticides to polychlorinat...

  15. GASN sheets

    International Nuclear Information System (INIS)

    This document gathers around 50 detailed sheets which describe and present various aspects, data and information related to the nuclear sector or, more generally to energy. The following items are addressed: natural and artificial radioactive environment, evolution of energy needs in the world, radioactive wastes, which energy for France tomorrow, the consequences in France of the Chernobyl accident, ammunitions containing depleted uranium, processing and recycling of used nuclear fuel, transport of radioactive materials, seismic risk for the basic nuclear installations, radon, the precautionary principle, the issue of low doses, the EPR, the greenhouse effect, the Oklo nuclear reactors, ITER on the way towards fusion reactors, simulation and nuclear deterrence, crisis management in the nuclear field, does nuclear research put a break on the development of renewable energies by monopolizing funding, nuclear safety and security, the plutonium, generation IV reactors, comparison of different modes of electricity production, medical exposure to ionizing radiations, the control of nuclear activities, food preservation by ionization, photovoltaic solar collectors, the Polonium 210, the dismantling of nuclear installations, wind energy, desalination and nuclear reactors, from non-communication to transparency about nuclear safety, the Jules Horowitz reactor, CO2 capture and storage, hydrogen, solar energy, the radium, the subcontractors of maintenance of the nuclear fleet, biomass, internal radio-contamination, epidemiological studies, submarine nuclear propulsion, sea energy, the Three Mile Island accident, the Chernobyl accident, the Fukushima accident, the nuclear after Fukushima

  16. Anaerobic biodegradability of kitchen waste

    OpenAIRE

    Neves, L.; Oliveira, Rosário; M. Mota; Alves, M.M.

    2002-01-01

    Biodegradability of synthetic and real kitchen wastes was assessed in batch assays, under different solid contents between 1,8 and 24% and waste/inoculum ratios between 0,2 and 29 VSwaste/Vsseed sludge. Methanization rate and cumulative methane production from synthetic wastes simulated with different blends of protein, carbohydrates, fat and cellulose were compared. Although the excess of protein, carbohydrates and cellulose enhanced the biodegradability by 16 to 48%, the excess of fat re...

  17. The use of mulch to increase Spider (Arachnidae) numbers; a habitat approach to biological insect control

    OpenAIRE

    Manns, Mrs. Hida R.; Murray, D L; Beresford, D. V.

    2008-01-01

    The potential for insect predators to contribute to a biological balance of insect species was explored with mulch. Insects were collected in pitfall traps in outdoor microplots over 3 seasons in southern Ontario, Canada. Treatments varied each season with crops of oats or soybeans, with residue of straw, corn stalks or paperfibre, and with residue tilled in or surface applied. In 2006 at the peak of spider population density there was a significant effect of the plant and the paperfibre r...

  18. The effect of covering and mulching on the soil temperature, growth and yield of tomato

    Directory of Open Access Journals (Sweden)

    Kosterna Edyta

    2014-12-01

    Full Text Available By improving the thermal and moisture conditions in the immediate vicinity of plants, plastic covers influenced the growth and development and increased the yield of vegetables. Soil mulching with organic material is one method of soil water protection and also helps maintain a constant soil temperature within the root system of crops. This study investigated the effect of plant covering and the type of straw applied to soil mulching (rye, corn, rape or buckwheat on the soil temperature, development of the plant and the yield of ‘Polfast’ F1 tomato. The effect of the straw was compared to a control plot without mulch. Soil temperature at a depth of 10 cm was higher in covered plots than in the plot without covers. The increase in soil temperature as a result of covering amounted to 1.3°C at 8:00 a.m. and 1.7°C at 2:00 p.m. Both in the morning and in the afternoon, the soil temperature in the plots without straw and without covers and under polypropylene fibre was higher than in the plots with straw. The application of covers resulted in higher aboveground parts of plants and higher leaf area compared to cultivation without covers. Irrespective of whether a covering was used, all of the types of straw investigated in the experiment caused the acceleration of growth and development of tomato plants. Simultaneous plant covering and soil mulching increased the total yield of fruits but did not have an influence on the share of marketable yield of the total yield.

  19. Effect of Tithonia diversifolia Mulch on Atta cephalotes (Hymenoptera: Formicidae) Nests

    OpenAIRE

    Rodríguez, Jonathan; Montoya-Lerma, James; Calle, Zoraida

    2015-01-01

    Recent studies have shown an insecticidal effect of Tithonia diversifolia (Hemsl.) Gray (Asterales: Asteraceae) foliage on workers of Atta cephalotes L. and inhibitory effects of this plant on the growth of the symbiotic fungus Leucoagaricus gongylophorus (A. Müler) Singer. To evaluate the potential of T. diversifolia as a biological control treatment of this important pest, we assessed the effect of green manure (mulch) of this plant on natural nests of A. cephalotes, in Cali, Colombia. Thre...

  20. The Role of Mulching with Residues of two Medicinal Plants on Weed Diversity in Maize

    OpenAIRE

    Kamariari, Iliana; Papastylianou, Panagiota; Dimitrios BILALIS; Travlos, Ilias; Ioanna KAKABOUKI

    2014-01-01

    In the present study, there were studied the effects of mulch with the residues of two aromatic and medicinal plants (Sideritis scardica Griseb and Echinacea purpurea) on weed flora and first growth of a maize crop. A field and a pot experiment were conducted at Agricultural University of Athens. In particular, the field experiment was conducted under organic conditions, while in the pot experiment special attention was paid to the first growth of maize plants under the effect of plant residu...

  1. Optimization of technical parameters for making mulch from waste cotton and rice straw fiber%废旧棉与水稻秸秆纤维混合地膜制造工艺参数优化

    Institute of Scientific and Technical Information of China (English)

    陈海涛; 明向兰; 刘爽; 张颖; 张鸿超

    2015-01-01

    The technology of plastic mulching was widely used, but its use depended on petroleum resources, which caused white pollution; straw was a rich resource in quantity, but large amount of waste straw was burned in the field, which caused the waste of resource and the environmental pollution at the same time. To solve the pollution of plastic film, plant fiber mulching has been developed, which was biodegradable mulching. There was lots of methyl cellulose in the biogas residue produced by anaerobic fermentation using ruminant feces. Crop residues, most often treated as waste material, could be used as raw material to produce biodegradable plastic membrane, and one technique may solve the white pollution brought by plastic mulching and the plant residue pollution. Waste cotton fiber came from human production and life with low price, so there was an urgent need to its re-utilization. Abandoned textiles were mostly disposed as garbage, and the recycle was very little, which resulted in serious waste of resource and environmental pollution. In abandoned textiles, cotton textiles were mostly confined, for cotton fiber was cut or broken, and through the re-processing, some low additional value products were produced, which hindered the establishment of the industrial chain of the waste textile recycling. In order to improve the utilization rate of waste cotton fabrics and crop straw, and provide technical support for making the biodegradable biogas residue fiber mulch, the processing and property of hybrid film produced by waste cotton and rice straw fiber were studied.The “skeleton” was waste cotton fiber, and filling material was rice straw fiber, with adding the additive that was environmental friendly. The method of four-factor and five-level quadratic regression orthogonal rotation center combination was applied. Beating degree, adding ratio, basis weight and wet strength agent were taken as influencing factors; dry tension strength and elongation, wet tension

  2. Vegetative growth and yield of strawberry under irrigation and soil mulches for different cultivation environments

    Directory of Open Access Journals (Sweden)

    Pires Regina Célia de Matos

    2006-01-01

    Full Text Available The vegetative growth and yield of strawberry in relation to irrigation levels and soil mulches are still not well known, mainly for different environmental conditions. Two experiments were carried out in Atibaia, SP, Brazil, during 1995, one in a protected environment and the other in an open field, to evaluate the cultivar Campinas IAC-2712, under different irrigation levels and soil mulches (black and clear polyethylene. Three water potential levels in the soil were used in order to define irrigation time, corresponding to -0.010 (N1, -0.035 (N2, and -0.070 (N3 MPa, measured through tensiometers installed at the 10 cm depth. A 2 x 3 factorial arrangement was adopted, as randomized complete block, with 5 replicates. In the protected cultivation, the irrigation levels of -0.010 and -0.035 MPa and the clear plastic mulch favored the vegetative growth, evaluated through plant height, maximum horizontal dimension of the plant, leaf area index, as well as by total marketable fruit yield and its components (mean number and weight of fruits per plant. In the open field cultivation, no effect of treatments due to rainfall were observed.

  3. Landscape mulches and termite nutritional ecology: growth and survival of incipient colonies of Coptotermes formosanus (Isoptera: Rhinotermitidae).

    Science.gov (United States)

    Sun, Jian-Zhong

    2007-04-01

    Alate swarms are one of the major visible signs of the expansion of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), in an area. Successful establishment of an incipient colony is thought to mainly rely on available food resources and moisture. The large-scale use of tree-based mulches in landscapes may inadvertently contribute to local establishment and growth of C. formosanus colonies. This research investigated the nutritional ecology of incipient colonies of C. formosanus feeding on seven tree-based, weathered, and nonweathered landscape mulches: pine straw, pine bark, cedar wood, water oak, eucalyptus, cypress, and melaleuca. Incipient colonies of C. formosanus feeding on pine straw, either weathered or nonweathered, produced significantly more progeny over the course of 1-yr feeding than colonies feeding on the other mulches tested. Regardless of weathered or not, the incipient colonies feeding on pine straw, eucalyptus, bald cypress, and water oak mulches had significantly greater survival rates after 360 d (53-77%) than colonies feeding on the other mulches tested (0-13%), but colonies feeding on nonweathered water oak had significantly lower survival (8%) than those kept on weathered water oak (58%). Colony fitness values were significantly different between the weathering treatment groups and among the different types of mulches. With regard to colony growth characteristics, three distinct growth patterns were identified: a high number of progeny (>100) with high colony survival rate (>50%), a medium number of progeny (12-50) with high colony survival rate (>50%), and a small number of progeny (0-10) with low colony survival rate (<5%). These findings suggest that different types of mulch substrates could significantly impact the nutritional ecology of the founding pairs and the successful establishment of incipient colonies during the swarming season. PMID:17461078

  4. Progress of biodegradable metals

    Directory of Open Access Journals (Sweden)

    Huafang Li

    2014-10-01

    Full Text Available Biodegradable metals (BMs are metals and alloys expected to corrode gradually in vivo, with an appropriate host response elicited by released corrosion products, then dissolve completely upon fulfilling the mission to assist with tissue healing with no implant residues. In the present review article, three classes of BMs have been systematically reviewed, including Mg-based, Fe-based and Zn-based BMs. Among the three BM systems, Mg-based BMs, which now have several systems reported the successful of clinical trial results, are considered the vanguards and main force. Fe-based BMs, with pure iron and Fe–Mn based alloys as the most promising, are still on the animal test stage. Zn-based BMs, supposed to have the degradation rate between the fast Mg-based BMs and the slow Fe-based BMs, are a rising star with only several reports and need much further research. The future research and development direction for the BMs are proposed, based on the clinical requirements on controllable degradation rate, prolonged mechanical stability and excellent biocompatibility, by optimization of alloy composition design, regulation on microstructure and mechanical properties, and following surface modification.

  5. Biodegradation of polyethoxylated nonylphenols.

    Science.gov (United States)

    Ruiz, Yassellis; Medina, Luis; Borusiak, Margarita; Ramos, Nairalith; Pinto, Gilberto; Valbuena, Oscar

    2013-01-01

    Polyethoxylated nonylphenols, with different ethoxylation degrees (NPEO x ), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native NPEO x and its derivatives. In this paper, the isolation of five bacterial strains, capable of using NPEO 15 , as unique carbon source, is described. The most efficient NPEO 15 degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% NPEO 15 medium. The NPEO 15 degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the NPEO 15 biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant (k) and half life time (τ) for this biotransformation were estimated to be 0.0072 h(-1) and 96.3 h, respectively. PMID:23936727

  6. Progress of biodegradable metals

    Institute of Scientific and Technical Information of China (English)

    Huafang Li; Yufeng Zheng; Ling Qin

    2014-01-01

    Biodegradable metals (BMs) are metals and alloys expected to corrode gradually in vivo, with an appropriate host response elicited by released corrosion products, then dissolve completely upon fulfilling the mission to assist with tissue healing with no implant residues. In the present review article, three classes of BMs have been systematically reviewed, including Mg-based, Fe-based and Zn-based BMs. Among the three BM systems, Mg-based BMs, which now have several systems reported the successful of clinical trial results, are considered the vanguards and main force. Fe-based BMs, with pure iron and Fe–Mn based alloys as the most promising, are still on the animal test stage. Zn-based BMs, supposed to have the degradation rate between the fast Mg-based BMs and the slow Fe-based BMs, are a rising star with only several reports and need much further research. The future research and development direction for the BMs are proposed, based on the clinical requirements on controllable degradation rate, prolonged mechanical stability and excellent biocompat-ibility, by optimization of alloy composition design, regulation on microstructure and mechanical properties, and following surface modification.

  7. Effects of Mulching and Nitrogen on Soil Nitrate-N Distribution, Leaching and Nitrogen Use Efficiency of Maize (Zea mays L.).

    Science.gov (United States)

    Wang, Xiukang; Xing, Yingying

    2016-01-01

    Mulching and nitrogen are critical drivers of crop production for smallholders of the Loess Plateau in China. The purpose of this study was to investigate the effect of mulching and nitrogen fertilizer on the soil water content, soil nitrate-N content and vertical distribution in maize root-zone. The experiment was conducted over two consecutive years and used randomly assigned field plots with three replicates. The six treatments consisted of no fertilizer without plastic film (CK), plastic film mulching with no basal fertilizer and no top dressing (MN0), basal fertilizer with no top dressing and no mulching (BN1), plastic film mulching and basal fertilizer with no top dressing (MN1), basal fertilizer and top dressing with no mulching (BN2) and plastic film mulching with basal fertilizer and top dressing (MN2). In the top soil layers, the soil water content was a little high in the plastic film mulching than that without mulching. The mean soil water content from 0 to 40 cm without mulching were 3.35% lower than those measured in the corresponding mulching treatments in 31 days after sowing in 2012. The mulching treatment increased the soil nitrate-N content was observed in the 0-40-cm soil layers. The results indicate that high contents of soil nitrate-N were mainly distributed at 0-20-cm at 31 days after sowing in 2012, and the soil nitrate-N concentration in the MN2 treatment was 1.58 times higher than that did not receive fertilizer. The MN2 treatment greatly increased the soil nitrate-N content in the upper layer of soil (0-40-cm), and the mean soil nitrate-N content was increased nearly 50 mg kg-1 at 105 days after sowing compared with CK treatment in 2012. The soil nitrate-N leaching amount in MN1 treatment was 28.61% and 39.14% lower than BN1 treatment, and the mulch effect attained to 42.55% and 65.27% in MN2 lower than BN2 in both years. The yield increased with an increase in the basal fertilizer, top dressing and plastic film mulching, and the grain

  8. Effects of the Biodegradation on Biodegradable Polymer Blends and Polypropylene

    Science.gov (United States)

    Pereira, R. C. T.; Franchetti, S. M. M.; Agnelli, J. A. M.; Mattoso, L. H. C.

    2008-08-01

    The large use of plastics in the world generates a large amount of waste which persists around 200 years in the environment. To minimize this effect is important to search some new polymer materials: the blends of biodegradable polymers with synthetic polymers. It is a large area that needs an intensive research to investigate the blends properties and its behavior face to the different treatments to aim at the biodegradation. The blends used in this work are: some biodegradable polymers such as: poly(hydroxybutyrate) (PHB) and poly(ɛ-polycaprolactone) (PCL) with a synthetic polymer, polypropylene (PP), in lower concentration. These blends were prepared using an internal mixer (Torque Rheometer), and pressed. These films were submitted to fungus biotreatment. The films analyses will be carried out by Fourier Transform Infrared (FTIR), UV-Vis absorption (UV-Vis), Scanning Electronic Microscopy (SEM), DSC and TGA.

  9. Modeling water flow and nitrate dynamics in a plastic mulch vegetable cultivation system using HYDRUS-2D

    Science.gov (United States)

    Filipović, Vilim; Romić, Davor; Romić, Marija; Matijević, Lana; Mallmann, Fábio J. K.; Robinson, David A.

    2016-04-01

    Growing vegetables commercially requires intensive management and involves high irrigation demands and input of agrochemicals. Plastic mulch application in combination with drip irrigation is a common agricultural management technique practiced due to variety of benefits to the crop, mostly vegetable biomass production. However, the use of these techniques can result in various impacts on water and nutrient distribution in underlying soil and consequently affect nutrient leaching towards groundwater resources. The aim of this work is to estimate the effect of plastic mulch cover in combination with drip irrigation on water and nitrate dynamics in soil using HYDRUS-2D model. The field site was located in Croatian costal karst area on a Gleysol (WRB). The experiment was designed according to the split-plot design in three repetitions and was divided into plots with plastic mulch cover (MULCH) and control plots with bare soil (CONT). Each of these plots received applications of three levels of nitrogen fertilizer: 70, 140, and 210 kg per ha. All plots were equipped with drip irrigation and cropped with bell pepper (Capsicum annuum L. cv. Bianca F1). Lysimeters were installed at 90 cm depth in all plots and were used for monitoring the water and nitrate outflow. HYDRUS-2D was used for modeling the water and nitrogen outflow in the MULCH and CONT plots, implementing the proper boundary conditions. HYDRUS-2D simulated results showed good fitting to the field site observed data in both cumulative water and nitrate outflow, with high level of agreement. Water flow simulations produced model efficiency of 0.84 for CONT and 0.56 for MULCH plots, while nitrate simulations showed model efficiency ranging from 0.67 to 0.83 and from 0.70 to 0.93, respectively. Additional simulations were performed with the absence of the lysimeter, revealing faster transport of nitrates below drip line in the CONT plots, mostly because of the increased surface area subjected to precipitation

  10. Influencia del mulch en los índices de crecimiento del frijol variedad «Bat-304»

    Directory of Open Access Journals (Sweden)

    Guillermo Hernández del Valle

    2008-01-01

    Full Text Available El empleo de coberturas, arropes o mulch es un factor importante en climas donde la evapotranspiración es elevada ya que su uso favorece la disminución de la temperatura del suelo y mantiene una humedad necesaria a la planta reduciendo la pérdida de agua por evaporación. Con el objetivo de determinar la influencia del mulch en índices crecimiento del fríjol (Phaseolus vulgaris L. de grano negro var. Bat-304, se realizó un experimento en las áreas agrícolas de la Facultad de Agronomía durante los meses de enero a abril de 2005 sobre un suelo Ferralítico Rojo típico. Los restos vegetales utilizados para el arrope se distribuyeron uniformemente sobre la superficie de las parcelas antes de la siembra, equivalente a 4, 5; 7; 5 y 15 t·ha-1 y un control sin mulch. Los tratamientos que recibieron los beneficios del mulch alcanzaron valores de índices de crecimiento significativamente superiores al tratamiento sin mulch, en cada fase fenológica, destacándose la aplicación equivalente a 15 t·ha-1 como el mejor resultado.

  11. Tillage and straw mulching impacts on grain yield and water use efficiency of spring maize in Northern Huang-Huai-Hai Valley

    Institute of Scientific and Technical Information of China (English)

    Zhiqiang Tao; Congfeng Li; Jingjing Li; Zaisong Ding; Jie Xu; Xuefang Sun; Peilu Zhou; Ming Zhao

    2015-01-01

    A two-year field experiment (2012–2013) was conducted to investigate the effects of two tillage methods and five maize straw mulching patterns on the yield, water consumption, and water use efficiency (WUE) of spring maize (Zea mays L.) in the northern Huang–Huai–Hai valley of China. Compared to rotary tillage, subsoil tillage resulted in decreases in water consumption by 6.3–7.8% and increases in maize yield by 644.5–673.9 kg ha−1, soil water content by 2.9–3.0%, and WUE by 12.7–15.2%. Chopped straw mulching led to higher yield, soil water content, and WUE as well as lower water consumption than prostrate whole straw mulching. Mulching with 50%chopped straw had the largest positive effects on maize yield, soil water content, and WUE among the five mulching treatments. Tillage had greater influence on maize yield than straw mulching, whereas straw mulching had greater influence on soil water content, water consumption, and WUE than tillage. These results suggest that 50%chopped straw mulching with subsoil tillage is beneficial in spring maize production aiming at high yield and high WUE in the Huang–Huai–Hai valley.

  12. Tillage and straw mulching impacts on grain yield and water use efficiency of spring maize in Northern Huang–Huai–Hai Valley

    Institute of Scientific and Technical Information of China (English)

    Zhiqiang; Tao; Congfeng; Li; Jingjing; Li; Zaisong; Ding; Jie; Xu; Xuefang; Sun; Peilu; Zhou; Ming; Zhao

    2015-01-01

    A two-year field experiment(2012–2013) was conducted to investigate the effects of two tillage methods and five maize straw mulching patterns on the yield, water consumption,and water use efficiency(WUE) of spring maize(Zea mays L.) in the northern Huang–Huai–Hai valley of China. Compared to rotary tillage, subsoil tillage resulted in decreases in water consumption by 6.3–7.8% and increases in maize yield by 644.5–673.9 kg ha-1, soil water content by 2.9–3.0%, and WUE by 12.7–15.2%. Chopped straw mulching led to higher yield,soil water content, and WUE as well as lower water consumption than prostrate whole straw mulching. Mulching with 50% chopped straw had the largest positive effects on maize yield, soil water content, and WUE among the five mulching treatments. Tillage had greater influence on maize yield than straw mulching, whereas straw mulching had greater influence on soil water content, water consumption, and WUE than tillage. These results suggest that 50% chopped straw mulching with subsoil tillage is beneficial in spring maize production aiming at high yield and high WUE in the Huang–Huai–Hai valley.

  13. Effects of mulch on soil properties and on the performance of late season cassava (Manihot esculenta Crantz on an acid ultisol in Southwestern Zaire

    Directory of Open Access Journals (Sweden)

    Lutaladio, NB.

    1992-01-01

    Full Text Available Mulch effects on soil temperature, soil moisture content, soil chemical properties, growth and development, yield and yield components of late season cassava were investigated for three years on an acid ultisol in the tropical sa vanna zone of Southwestern Zaire. Diurnal soil temperature and soil moisture content were recorded at 30-day intervals during the first 4 months of growth. Cassava growth and development were monitored a t3, 6 and 9 months after planting while yield and yield components were noted at 12 months after planting. After each cropping year, changes in soil chemical constituents were recorded. Mulching significantly reduced soil temperature by about 3.5°C and increased soil moisture content by 6.1 % under late season cassava. Soil pH, soil organic carbon content, total nitrogen, soil available phosphorus and soil exchangeable cations (Ca, Mg, K increased as a result of increase in organic matter with continuous application of mulch for 3 years. Plant height, leaf area, shoot and root dry weights of cassava plants given mulch were significantly increased as compared to the plants in unmulched plots. Cassava plants given mulch produced more and bigger storage roots than unmulched plants. Storage root yield increased by 16.7, 28.1 and 57.7 % respectively in the first, the second and the third years of mulch application. The beneficiai effect of mulching over no-mulching increased from year to year, irrespective of cassava cultivars.

  14. Adhesion of biocompatible and biodegradable micropatterned surfaces

    NARCIS (Netherlands)

    Kaiser, J.S.; Kamperman, M.M.G.; Souza, E.J.; Schick, B.; Arzt, E.

    2011-01-01

    We studied the effects of pillar dimensions and stiffness of biocompatible and biodegradable micropatterned surfaces on adhesion on different compliant substrates. The micropatterned adhesives were based on biocompatible polydimethylsiloxane (PDMS) and biodegradable poly(lactic-co-glycolic) acid (PL

  15. Poly (3-Hydroxyalkanoates: Biodegradable Plastics

    Directory of Open Access Journals (Sweden)

    Surbhi Jain

    2013-03-01

    Full Text Available During the 1920’s, a polyester called poly (3-hydroxybutyrate was discovered in bacterial cells. This compound, otherwise known as PHB, is part of a polyester family called polyhydroxyalkanoates (PHAs. Polyhydroxyalkanoates are used as an energy and carbon sto rage compound within certain bacterial cells. Polyhydroxyalkanoates (PHAs are thermoplastic, biodegradable polyesters synthesized by some bacteria from renewable carbon sources. However, their application is limited by high production cost. Polyhydroxyalkanoates (PHAs have attracted research and commercial interests worldwide because they can be used as biodegradable thermoplastics and also because they can be produced from renewable resources. This review will present an overview on synthesis and degradation of polyhydroxyalkanoates (PHAs, development as biodegradable plastics and its potential production from renewable resources such as palm oil products.

  16. The effects of mulching on soil erosion by water. A review based on published data

    Science.gov (United States)

    Prosdocimi, Massimo; Jordán, Antonio; Tarolli, Paolo; Cerdà, Artemi

    2016-04-01

    Among the soil conservation practices that have been recently implemented, mulching has been successfully applied in different contexts (Jordán et al., 2011), such as agricultural lands (García-Orenes et al. 2009; Prosdocimi et al., 2016), fire-affected areas (Prats et al., 2014; Robichaud et al., 2013) and anthropic sites (Hayes et al., 2005), to reduce water and soil losses rates. In these contexts, soil erosion by water is a serious problem, especially in semi-arid and semi-humid areas of the world (Cerdà et al., 2009; Cerdan et al., 2010; Sadeghi et al., 2015). Although soil erosion by water consists of physical processes that vary significantly in severity and frequency according to when and where they occur, they are also strongly influenced by anthropic factors such as unsustainable farming practices and land-use changes on large scales (Cerdà, 1994; Montgomery, 2007). Although the beneficial effects of mulching are known, their quantification needs further research, especially in those areas where soil erosion by water represents a severe threat. In literature, there are still some uncertainties about how to maximize the effectiveness of mulching in the reduction of soil and water loss rates. First, the type of choice of the vegetative residues is fundamental and drives the application rate, cost, and consequently, its effectiveness. Second, it is important to assess application rates suitable for site-specific soil and environment conditions. The percentage of area covered by mulch is another important aspect to take into account, because it has proven to influence the reduction of soil loss. And third, the role played by mulching at catchment scale, where it plays a key role as barrier for breaking sediment and runoff connectivity. Given the seriousness of soil erosion by water and the uncertainties that still concern the correct use of mulching, this work aims to evaluate the effects of mulching on soil erosion rates and water losses in agricultural

  17. [Effects of Green Manure Intercropping and Straw Mulching on Winter Rape Rhizosphere Soil Organic Carbon and Soil Respiration].

    Science.gov (United States)

    Zhou, Quan; Wang, Long-chang; Xiong, Ying; Zhang, Sai; Du, Juan; Zhao, Lin-lu

    2016-03-15

    Under the background of global warming, the farmland soil respiration has become the main way of agricultural carbon emissions. And green manure has great potential to curb greenhouse gas emissions and achieve energy conservation and emissions reduction. However, in purple soil region of Southwest, China, soil respiration under green manure remains unclear, especially in the winter and intercropping. Through the green manure ( Chinese milk vetch) intercropping with rape, therefore, we compared the effects of rape rhizosphere under straw mulching. The soil organic carbon and soil respiration were examined. The results showed, compared with straw mulching, root separation was the major influencing factors of soil organic carbon on rape rhizosphere. Soil organic carbon was significantly decreased by root interaction. In addition, straw mulching promoted while green manure intercropping inhibited the soil respiration. Soil respiration presented the general characteristics of fall-rise-fall due to the strong influence of rape growth period. Therefore, it showed a cubic curve relationship with soil temperature. PMID:27337908

  18. Highly organic natural media as permeable reactive barriers: TCE partitioning and anaerobic degradation profile in eucalyptus mulch and compost.

    Science.gov (United States)

    Öztürk, Zuhal; Tansel, Berrin; Katsenovich, Yelena; Sukop, Michael; Laha, Shonali

    2012-10-01

    Batch and column experiments were conducted with eucalyptus mulch and commercial compost to evaluate suitability of highly organic natural media to support anaerobic decomposition of trichloroethylene (TCE) in groundwater. Experimental data for TCE and its dechlorination byproducts were analyzed with Hydrus-1D model to estimate the partitioning and kinetic parameters for the sequential dechlorination reactions during TCE decomposition. The highly organic natural media allowed development of a bioactive zone capable of decomposing TCE under anaerobic conditions. The first order TCE biodecomposition reaction rates were 0.23 and 1.2d(-1) in eucalyptus mulch and compost media, respectively. The retardation factors in the eucalyptus mulch and compost columns for TCE were 35 and 301, respectively. The results showed that natural organic soil amendments can effectively support the anaerobic bioactive zone for remediation of TCE contaminated groundwater. The natural organic media are effective environmentally sustainable materials for use in permeable reactive barriers. PMID:22795070

  19. Use of organic mulch to enhance water-use efficiency and peach production under limiting soil conditions in a three-year-old orchard

    Directory of Open Access Journals (Sweden)

    Joan Lordan

    2015-12-01

    Full Text Available Mulching techniques have emerged in recent years to overcome soil constraints and improve fruit tree productivity. The object of this study was to evaluate the effects of a low-cost organic mulch application in a newly planted peach orchard under a ridge planting system. Three treatments were performed in 12 elementary plots using a randomized complete block design. The orchard was drip-irrigated. Mulch was applied in two treatments, which differed in fertigation (none vs. multi-nutrient fertigation, while the third treatment did not include either mulch or fertigation and served as the control. Treatments were compared in terms of their effects on the physical properties of the soil, crop response, and water-use efficiency. Mulch treatments did not alter the soil bulk density. However, the mulch significantly (p=0.0004 increased the water infiltration rate (2.21 mm/h vs. 121 mm/h, which is a key issue when working in high frequency irrigation systems under soil limiting conditions. Similarly, mulched treatments showed a more favorable water status both in the second and the third year, which was translated in a better crop response. Thus, mulched treatments recorded higher yields both in the second (+155%, p=0.0005 and the third year (+53%, p=0.0007 of the experiment. Water use efficiency (WUEagr was higher in the mulch treatments (+50% in average, p=0.0007 than in the control in the third year of the study. On the basis of our results, we propose that organic-mulching techniques should be considered as a beneficial practice to apply in fruit-trees production under limiting soil conditions.

  20. Suitability of Pueraria phaseoloides, Chromolaena odorata and Tithonia diversifolia as in-situ mulch for nematode management in musa cropping systems.

    Science.gov (United States)

    Schösser, B; Hauser, S; Sikora, R A

    2006-01-01

    Mulching with plant organic matter has been shown to reduce nematode population densities in various cropping systems. The level of nematode control is increased when such mulches are incorporated into the soil as organic amendments. Chromolaena odorata, Tithonia diversifolia and Pueraria phaseoloides are common cover crops in West and Central Africa that produce large quantities of nutrient rich biomass. The aim of this study was to determine, if in-situ mulching of C. odorata, T. diversifolia and P. phaseoloides is suitable for nematode control in Musa production. In a pot trial, the susceptibility of these plants to spiral nematodes was investigated. The effects of different quantities of surface mulch on nematode population densities in the soil and in banana roots also were determined. All mulch types and all quantities led to a reduction in nematode population densities in the soil. The strongest nematode reductions were observed in the Pueraria treatments. In treatments containing banana plants mulching improved plant growth compared to the clean-fallowed soil and induced lower root infestation rates. However, nematode soil populations were higher in mulched than in non-mulched banana treatments. Plant parasitic nematodes also were isolated from roots of all three cover crop species and all three plants caused an increase in nematode numbers in the soil. Therefore, the tested cover crops proved unsuitable for nematode control in a system with the highly susceptible bananas. Further examinations are needed to determine whether or not the positive effects of surface mulching on plantain plant growth and root infestation rates also have positive effects on yield in an in-situ mulching system in the presence of nematodes. PMID:17390809

  1. Structural Biology Fact Sheet

    Science.gov (United States)

    ... Home > Science Education > Structural Biology Fact Sheet Structural Biology Fact Sheet Tagline (Optional) Middle/Main Content Area What is structural biology? Structural biology is a field of science focused ...

  2. Respirator Fact Sheet

    Science.gov (United States)

    ... Products NIOSH-Issued Publications Publication Types Alerts Current Intelligence Bulletins Criteria Documents Fact Sheets Health Hazard Evaluations ( ... using gas mask and escape respirators. At the end of this Fact Sheet, you will find a ...

  3. The effect of mulching on water consumption, yield and some parameters in apple orchards grafted onto dwarf rootstock

    Directory of Open Access Journals (Sweden)

    Cenk KÜÇÜKYUMUK

    2013-06-01

    Full Text Available This study was conducted to determine the effect of different mulch materials on plant water consumption, yield, fruit quality, vegetative growth, and weed control and soil temperature of Braeburn apple variety grafted onto M9 rootstock in Eğirdir Fruit Growing Research Station in 2010-2011. The experimental design was a randomized block design with three replications. Three different treatments were determined as two different mulch materials (white fabric, black plastic covering and control (without any mulching. Irrigation water was applied by using drip irrigation system in 7 days intervals. Amount of irrigation water to be applied in the each irrigation was determined as water amount needed for raising the soil moisture to the field capacity in 0-60 cm soil depth. As a result, substantial water saving has been provided from both of the mulch materials (%< 22-28 in comparison with the control treatment. The yield results showed statistically significant difference (p<0.05 among the treatments only in the second year. The highest red colour density value, which is an important criterion in apple marketing, was obtained from mulching with white fabric for both years. It was determined that mulch applications with these two materials were positive effects on vegetative growth and they were very effective on weed control. Soil temperature measured in the treatment used white fabric was found 1-2°C lower in comparison with control treatment, while it was found 3-4°C lower in comparison with the black plastic covering.

  4. Biodegradable congress 2012; Bioschmierstoff-Kongress 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Within the Guelzower expert discussions at 5th and 6th June, 2012 in Oberhausen (Federal Republic of Germany) the following lectures were held: (1) Promotion of biodegradable lubricants by means of research and development as well as public relations (Steffen Daebeler); (2) Biodegradable lubricants - An overview of the advantages and disadvantages of the engaged product groups (Hubertus Murrenhoff); (3) Standardization of biodegradable lubricants - CEN/DIN standard committees - state of the art (Rolf Luther); (4) Market research for the utilization of biodegradable lubricants and means of proof of sustainability (Norbert Schmitz); (5) Fields of application for high performance lubricants and requirements upon the products (Gunther Kraft); (6) Investigations of biodegradable lubricants in rolling bearings and gears (Christoph Hentschke); (7) Biodegradable lubricants in central lubrication systems Development of gears and bearings of offshore wind power installations (Reiner Wagner); (8) Investigations towards environmental compatibility of biodegradable lubricants used in offshore wind power installations (Tolf Schneider); (9) Development of glycerine based lubricants for the industrial metalworking (Harald Draeger); (10) Investigations and utilization of biodegradable oils as electroinsulation oils in transformers (Stefan Tenbohlen); (11) Operational behaviour of lubricant oils in vegetable oil operation and Biodiesel operation (Horst Hamdorf); (12) Lubrication effect of lubricating oil of the third generation (Stefan Heitzig); (13) Actual market development from the view of a producer of biodegradable lubricants (Frank Lewen); (14) Utilization of biodegradable lubricants in forestry harvesters (Guenther Weise); (15) New biodegradable lubricants based on high oleic sunflower oil (Otto Botz); (16) Integrated fluid concept - optimized technology and service package for users of biodegradable lubricants (Juergen Baer); (17) Utilization of a bio oil sensor to control

  5. Influencia del mulch en los índices de crecimiento del frijol variedad «Bat-304»

    OpenAIRE

    Guillermo Hernández del Valle; Pedro León Noguera; Orestes Cruz la Paz; Yvonne Indrani Ramnarain

    2008-01-01

    El empleo de coberturas, arropes o mulch es un factor importante en climas donde la evapotranspiración es elevada ya que su uso favorece la disminución de la temperatura del suelo y mantiene una humedad necesaria a la planta reduciendo la pérdida de agua por evaporación. Con el objetivo de determinar la influencia del mulch en índices crecimiento del fríjol (Phaseolus vulgaris L.) de grano negro var. Bat-304, se realizó un experimento en las áreas agrícolas de la Facultad de Agronomía durante...

  6. Effects of straw mulch on yield, weed development, nitrate dynamics and soil erosion in organically grown potatoes

    OpenAIRE

    Döring, Thomas F; Brandt, M.; Heß, J; Finckh , M; Saucke, H

    2005-01-01

    The application of straw mulch to organic seed potatoes (Solanum tuberosum L.) has been shown to reduce virus incidence. In order to determine the associated agronomic effects of straw mulch, applied at 2.5–5 t ha�1, on soil nitrate dynamics, weed development, tuber yield and soil erosion, 12 field experiments were evaluated. Experiments were conducted on organic farms over 3 years at two locations in a temperate climate (635–709 mm precipitation/year; 8.1 8C mean air temperature) on loamy si...

  7. Energy balance and evapotranspiration of melon grown with plastic mulch in the Brazilian semiarid region

    Directory of Open Access Journals (Sweden)

    Valéria Peixoto Borges

    2015-10-01

    Full Text Available Melon plants (Cucumis melo L. are grown in the state of Rio Grande do Norte (RN, the largest producer of melons in Brazil, with plastic mulch and agrotextiles. Studies of crop evapotranspiration (ET under these conditions are required to ensure adequate irrigation. This study aimed to determine the crop coefficients (Kc of irrigated melon plants grown with mulch and agrotextiles in the region of Mossoró, RN, based on the Bowen Ratio Energy Balance (BREB method. Two experiments were conducted at different times during the 2009/2010 season in a melon producing area (4°59'52" S, 37°23'09" W, and 54 m elevation to define ET and Kc. Due to the plastic cover and reduced precipitation during the experiments, the Kc obtained by the BREB method was considered the basal Kc - KcbBREB. The results were compared with the Kcb from the FAO 56 Bulletin. There was close agreement between BREB and FAO ET measurements (12 % underestimation by the FAO method for the entire crop season, with sizeable differences only during the initial phenological stage. The mean KcbBREB values of the two field campaigns were 0.26, 0.96 and 0.63 for the initial, midseason and late stages, respectively. The high KcbBREB value in the initial growth phase may be related to the effect of the plastic mulch and agrotextiles on the energy balance at the surface. The relationship between KcbBREB and fc had high correlation, making possible an estimation of the melon Kcb based on the level of crop ground cover.

  8. Surface Drainage and Mulching Drip-Irrigated Tomatoes Reduces Soil Salinity and Improves Fruit Yield

    Science.gov (United States)

    Hou, Maomao; Zhu, Lvdan; Jin, Qiu

    2016-01-01

    A study on the effects of mulched drip irrigation combined with surface drainage on saline soil and tomatoes was conducted in coastal areas of eastern China, where the crops are subjected to excessive salt. The treatments contained three irrigation rates—200, 250 and 300 m3/ha—and three drain ditch depths—10, 20 and 30 cm. The contents of soil salinity, organic matter and available nutrient were observed, and the tomato plant height, stem diameter and leaf area index during different growth periods were recorded. Results showed that the total removal rate of salt from soil at a 0–1 m depth was 8.7–13.2% for the three drainages. Compared with the control, the treatments increased the content of available N (by 12.1–47.1%) and available K (by 5.0–21.9%) in the soils inside the mulch and decreased the content of available N (by 3.4–22.1%) and available K (by 7.5–16.4%) in the soils outside the mulch. For tomatoes, the plant height and the stem diameter was increased significantly by the irrigations but was not significantly affected by the drainages, and the leaf area index was increased by 0.39~1.76, 1.10~2.90 and 2.80~6.86 respectively in corresponding to the seedling, flowering and fruit-set stage. Moreover, yield-increase rates of 7.9–27.6% were found for the treatments compared to the control with a similar amount of applied water. PMID:27153110

  9. Biodegradation kinetics at low concentrations (

    DEFF Research Database (Denmark)

    Toräng, Lars; Albrechtsen, Hans-Jørgen; Nyholm, Niels

    Aerobic biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in groundwater added sediment fines. At concentrations at or below 1 mu g/L of 2,4-D degradation kinetic was of true first order without significant growth of specific degraders and with half-life for mineralization in the...

  10. Biodegradable Pectin/clay Aerogels

    Science.gov (United States)

    Biodegradable, foamlike materials based on renewable pectin and sodium montmorillonite clay were fabricated through a simple, environmentally friendly freeze-drying process. Addition of multivalent cations (Ca2+ and Al3+) resulted in apparent crosslinking of the polymer, and enhancement of aerogel p...

  11. Effects of Soil Water Content on Cotton Root Growth and Distribution Under Mulched Drip Irrigation

    Institute of Scientific and Technical Information of China (English)

    HU Xiao-tang; CHEN Hu; WANG Jing; MENG Xiao-bin; CHEN Fu-hong

    2009-01-01

    The relation between soil water content and the growth of cotton root was studied for the scheme of field water and cotton yield under mulched drip irrigation.Based on the field experiments,three treatments of soil water content were conducted with 90%θf,75%θf,and 60%θf (θf is field water capacity).Cotton roots and root-shoot ratio were studied with digging method,and the soil moisture was observed with TDR (time domain reflector),and cotton yield was measured.The results indicated that the growth of cotton root accorded with Logistic growth curve in the three treatments,the cotton root grew quickly and its weight was very high under 75%θf because of the suitable soil water condition,while grew slowly and its weight was lower under 90%θf due to water moisture beyond the suitable condition,and the root weight was in between under 60%θf.For the three water treatments,the cotton root weight decreased with soil depth,and decreased more significantly in deeper soil layer with the soil moisture increasing.And the ratio of cotton root weight in 0-30 cm soil layer to the total root weight was the highest under 75%θf.The cotton root system was distributed mainly in the soil of narrow row and wide row mulched with plastic film,and little in the soil outside plastic film.The weight of cotton root was the highest in the soil of narrow row or wide row mulched with plastic film under 75%θf.Root-shoot ratio decreased with the soil moisture increasing.The soil water content affected cotton yields,and cotton yield was the highest under 75%θf.The higher soil moisture level is unfavorable to the growth of cotton root system and yield of cotton under mulched drip irrigation.

  12. Straw mulch in organically grown potatoes - evaluation and optimisation for virus vector control

    OpenAIRE

    Thomas F Döring

    2004-01-01

    1. In order to evaluate effects of straw mulch applied at 2.5 – 5 t ha-1 in organically grown potatoes (Solanum tuberosum L.), 21 field experiments were conducted over five years at two locations Northern Hessen and Southern Niedersachsen, Germany). The experimental sites were characterised by temperate climate conditions (635 – 709 mm precipitation year-1; 8.1°C mean air temperature) and loamy silt soils. The main focus of the study was on aphids and the aphidtransmitted Potato viru...

  13. Effect of Mulching Rates on Evaporation, Water and Salt Distribution in two soils with different texture from Upper Soil Layer, in Derab region, Kingdom of Saudi Arabia

    International Nuclear Information System (INIS)

    Dry desert climate zone require search for the best ways to, conserve water. This study was conducted to minimize evaporation using mulching with different rates in two soils loamy sand (S1), and sandy clay loam (S2). Sawdust mulch rates used were (zero, 2, and 4 cm) depth. Tape water was added to soil columns on the basis of required water to saturate soil. After the leach ate (free water drainage) ceased, evaporation experiment was started until stable weight of the control (no mulch) was achieved (83 days). The cumulative evaporation (E) was determined by daily weighing soil columns. The soil waters and salts distribution on soil profiles was determined by daily weighing soil columns. The soil water and soil distribution on soil profiles were determined each (10cm) increments before and after evaporation experiments. Results indicated that the two soils had different hydro physical properties, such that sandy clay loam soil (S2) was higher in water retention. The study revealed that sawdust mulching reduced evaporation significantly on both soils. Mulching with (2cm.) depth was enough for evaporation reduction to a rate lower than that of water flow toward soil surface. Results indicated that there is a linear relationship between (E) and square root of (t) (E=bt1/2) for all mulching rates of both soils. It has been found that the soil water profile distribution was significantly higher with mulched soil columns compared with the control for both soils. However, there were no significant differences between saw dust mulching with (2 or 4 cm depth). These results were reflected on the soil water storage, where mulched soil columns were higher than that of the control. In general results of evaporation, soil water distribution and water storage proved that sawdust mulching with (2cm) depth was enough to limit evaporation and conserve water for both soils. This effect was more pronounced in loamy sand soil. Generally, the result of the (EC) and salt distribution

  14. Effects of different patterns surface mulching on ground temperature, humidity and soil moisture%不同地表覆盖对地表温度、湿度和土壤水分的影响

    Institute of Scientific and Technical Information of China (English)

    彭超; 陈月华; 吴际友

    2014-01-01

    以土壤为对象,研究在高温下5种不同覆盖方式(清耕处理、地膜覆盖、秸秆覆盖、枝叶覆盖、灌木覆盖)对土壤性状的影响。结果表明,5种覆盖方式在高温下对土壤性状产生了影响:地膜覆盖提高了地表温度,且地膜覆盖下的地表温度上升最快,上升幅度最大,秸秆覆盖、枝叶覆盖和灌木覆盖则降低了地表温度,灌木覆盖的降温效果最好;地膜覆盖、秸秆覆盖、枝叶覆盖和灌木覆盖都能提高地表湿度,其中地膜覆盖前期保湿效果最好,后期则低于清耕处理;地膜覆盖的土壤水分散失最慢最少,秸秆覆盖和枝叶覆盖次之,灌木覆盖的水分散失最快最多。%Taking soil as testing object, the effects of different surface mulching patterns (clean tillage, plastic film mulch, straw mulch, litter mulch and shrub mulch) on soil properties have been studied. The results showed that the five surface mulching patterns all had influences on the soil properties under the condition of high temperature. With the patterns of clean tillage and plastic film mulch, the ground temperature were raised and was the fastest-growing and the largest increase;with the patterns of straw mulch, litter mulch and shrub mulch, the ground temperature lowed down and the cooling effect of shrub cover was the best;the patterns of plastic film mulch, straw mulch, litter mulch and shrub mulch all can improve the surface humidity, of them, the plastic film mulch in the earlier stage had the best moisturizing effect, later was lower than clean cultivation;the soil moisture loss covered with plastic film mulch had the least decrease in later stage and that of straw mulch and litter mulch were the next in turn, that of shrub mulch evaporated fastest and greatest.

  15. Integration of row spacing, mulching and herbicides on weed management in tomato

    International Nuclear Information System (INIS)

    A field experiment was conducted at the Research Farm of The University of Agriculture, Peshawar during the year 2012 to determine the impact of row spacing and weed management strategies on tomato (Lycopersicon esculentum Mill.). The local variety 'Roma' was sown in a randomized complete block (RCB) design with split plot arrangements, having four replications. The main plots were row spacings while subplots of the experiment comprised of ten treatments including five mulches viz., white and black polyethylene, wheat straw, newspaper and saw dust, three herbicide treatments (fenoxaprop-p-ethyl, pendimethalin and s-metolachlor), hand weeding and a weedy check. The data were recorded on weed density m/sup -2/, fresh and dry weed biomass, number of branches plant-1, and fruit yield (kg ha/sup -1/). All these parameters were significantly affected by row spacing and weed management treatments. Increase in weed population was observed with increasing in row spacing. The competitiveness of tomato with weeds can be enhanced by using black plastic as mulch. In light of the results, the row spacing of 60 cm is the optimum one for tomato plants, as the fruit yields decreased at 40 cm and 80 cm row spacing. (author)

  16. Comparison of different cover crop mulches and extracts on inhibition of crop and weed growth

    Directory of Open Access Journals (Sweden)

    Sturm, Domonic Johannes

    2016-02-01

    Full Text Available Weed suppression of cover crops is a result of competition for light, space, water and nutrients and the release of allelochemicals in the soil. Two laboratory and greenhouse experiments were conducted to analyse biochemical effects of extracts and mulches of Fagopyrum tataricum (L. Gaertn., Raphanus sativus var. oleiformis Pers. and a cover crop mixture on germination and plant growth of the crop plants maize (Zea mays L. and sugar beet (Beta vulgaris ssp. vulgaris var. altissima Döll. and the weeds Chenopodium album L., Matricaria chamomilla L. and Stellaria media (L. Vill.. In the first experiment, aqueous cover crop extracts were applied on crop and weed seeds in germination assays. Germination rate, mean germination time and root length of crops and weeds were measured. In experiment 2, the influence of cover crop mulch on germination rate and dry weight of the test plants was determined after a period of 21 days. Significant reductions of the root length for all test plants were observed in experiment 1. Additionally, mean germination time was extended for crops and weeds by all cover crops. Germination rate and dry matter of crops and weeds were decreased significantly in experiment 2 compared to the untreated control. Root length, germination rate and mean germination time in germination tests in experiment 1 were found to be correlated with biomass of crops and weeds in experiment 2. This work reveals the important role of biochemical effects on weed suppression by cover crops.

  17. Reflective Polyethylene Mulch Reduces Mexican Bean Beetle (Coleoptera: Coccinellidae) Densities and Damage in Snap Beans.

    Science.gov (United States)

    Nottingham, L B; Kuhar, T P

    2016-08-01

    Mexican bean beetle, Epilachna varivestis Mulsant, is a serious pest of snap beans, Phaseolus vulgaris L., in the eastern United States. These beetles are intolerant to direct sunlight, explaining why individuals are typically found on the undersides of leaves and in the lower portion of the plant canopy. We hypothesized that snap beans grown on reflective, agricultural polyethylene (plastic mulch) would have fewer Mexican bean beetles and less injury than those grown on black plastic or bare soil. In 2014 and 2015, beans were seeded into beds of metallized, white, and black plastic, and bare soil, in field plots near Blacksburg, VA. Mexican bean beetle density, feeding injury, predatory arthropods, and snap bean yield were sampled. Reflected light intensity, temperature, and humidity were monitored using data loggers. Pyranometer readings showed that reflected light intensity was highest over metallized plastic and second highest over white plastic; black plastic and bare soil were similarly low. Temperature and humidity were unaffected by treatments. Significant reductions in Mexican bean beetle densities and feeding injury were observed in both metallized and white plastic plots compared to black plastic and bare soil, with metallized plastic having the fewest Mexican bean beetle life stages and injury. Predatory arthropod densities were not reduced by reflective plastic. Metallized plots produced the highest yields, followed by white. The results of this study suggest that growing snap beans on reflective plastic mulch can suppress the incidence and damage of Mexican bean beetle, and increase yield in snap beans. PMID:27341891

  18. Biobased and biodegradable polymer nanocomposites

    Science.gov (United States)

    Qiu, Kaiyan

    In this dissertation, various noncrosslinked and crosslinked biobased and biodegradable polymer nanocomposites were fabricated and characterized. The properties of these polymer nanocomposites, and their relating mechanisms and corresponding applications were studied and discussed in depth. Chapter 1 introduces the research background and objectives of the current research. Chapter 2 presents the development of a novel low cost carbon source for bacterial cellulose (BC) production and fabrication and characterization of biobased polymer nanocomposites using produced BC and soy protein based resins. The carbon source, soy flour extract (SFE), was obtained from defatted soy flour (SF) and BC yield achieved using SFE medium was high. The results of this study showed that SFE consists of five sugars and Acetobacter xylinum metabolized sugars in a specific order. Chapter 3 discusses the fabrication and characterization of biodegradable polymer nanocomposites using BC and polyvinyl alcohol (PVA). These polymer nanocomposites had excellent tensile and thermal properties. Crosslinking of PVA using glutaraldehyde (GA) not only increased the mechanical and thermal properties but the water-resistance. Chapter 4 describes the development and characterization of microfibrillated cellulose (MFC) based biodegradable polymer nanocomposites by blending MFC suspension with PVA. Chemical crosslinking of the polymer nanocomposites was carried out using glyoxal to increase the mechanical and thermal properties as well as to make the PVA partially water-insoluble. Chapter 5 reports the development and characterization of halloysite nanotube (HNT) reinforced biodegradable polymer nanocomposites utilizing HNT dispersion and PVA. Several separation techniques were used to obtain individualized HNT dispersion. The results indicated uniform dispersion of HNTs in both PVA and malonic acid (MA) crosslinked PVA resulted in excellent mechanical and thermal properties of the materials, especially

  19. The effects of liquid-coating mulch spray on growth, yield and undersoil temperature in komatsuna greens (Brassica rapa L.)

    International Nuclear Information System (INIS)

    This experiment was intended to examine the effects of a black liquid-coating mulch on the growth and yield of komatsuna greens. Four treatments (1, 0.5, 0.25 and 0 L/square m) of spray amount were tested in combination with seeding date (Sep. 21sup(st), Oct. 5sup(th), Oct. 20sup(th) in an open field and the Jan. 22sup(nd) in a plastic film house). As a result, we found this liquid-coating mulch increased yields of komatsuna greens, unrelated to the spray amount. Generally, the daily highest soil temperature (-5 cm) under the mulching exceeded the control in every treatment however the daily lowest temperature was less than control except in the case of seeding at Sep. 21sup(st). These phenomena were remarkable in the early stage of growing and the differences in temperature between the control and mulch treatments were reduced during the growth. There was no significant difference in the hourly-integrated temperature during the first 10 days between the 4 treatments on same seeding date. These findings suggest that the expansion of the daily soil temperature range contributed the increased yields of komatsuna greens

  20. The Ratio between Leave and Fruit Parameters on ‘William’ Pear Orchard Affected by Regulated Deficit Irrigation and Mulching

    Directory of Open Access Journals (Sweden)

    LAVDIM LEPAJA

    2016-03-01

    Full Text Available This field experiment was designed to assess the ratio between leave and fruit parameters on young ‘William’ pear trees after applied regulated deficit irrigation (RDI and mulching. Experiments related to deficit irrigation and particularly regulated deficit irrigation (RDI or partial rootzone drying depend heavily on weather conditions. Using a water budget methodology, four levels of irrigation, specifically 100% of evapotranspiration (ET as control and deficits of 80%, 60% and 40%, were applied to 10 trees during the season, 5 of which were mulched with wood chips at a 10 cm layer in first year of experiment while, 20 cm in second year. The experiment was conducted in Kosovo during 2013-2015 on a pear orchard of 10 ha using a nested experimental design. Using two-way ANOVA we found significant changes in a series of leave and fruit parameters. Our results confirmed that a moderate water stress increase yield while, reducing excessive vegetative growth. Regulated deficit irrigation (40 % has contributed to the reduction on leaf surface, leaf area, LAI. In addition, RDI affected to increase fruit numbers but decreasing fruit size. Compared with first year of experiment during 2015 in treatment 40 % were achieved 5 kg more than 2013 year. Except this, mulching had a positive effect on all parameter values measured compared to non-mulched trees. Our result indicated that regulated deficit irrigation can be successfully applied to pear also, RDI is an ideal water saving technique.

  1. Response of Watermelon to Gravel-Mulch and Supplementary Irrigation:Yield,Water Use Efficiency and Root Distribution

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-shan; LI Xin-rong; ZHANG Pei-dong; ZHANG Jing-guang; WANG Xin-ping; LIU Li-chao

    2004-01-01

    A field experiment was conducted to investigate the effect of supplementary irrigation on watermelon (Citullus lanatus) yield, water-use efficiency (WUE) and root distribution in gravel-mulched field in northwest Loess Plateau, China, during 2001 and 2002 growing seasons. The results showed that gravel mulch significantly improved seedling emergence,increased yield and WUE, and alleviated the influence of drought on plant growth. Regardless of gravel mulch application, supplementary irrigation increased watermelon yields, average fruit weight and number of fruit, especially yield increased as the amount of irrigation increased (P<0.05). Generally, WUE of irrigated treatments were higher than that of non-irrigation treatment in gravel-mulched field. The effect of water supply on root distribution was different in two years. In 2001, average root length density (RLD) and root weight density (RWD) whole the soil profile increased. In 2002, however, RLD and RWD decreased as water supply increased. The average RLD and RWD in 2001 were significantly higher than those in 2002. Maybe we can interpret the phenomenon with the theory that there is a need to optimize root distribution (in termsof water relations) and aboveground biomass for a given water supply. The yield may not depend as much on root growth as on the amount of water required at critical stages. A significant effect of soil depth on RLD and RWD were observed in both years, but did not rapidly decrease with depth.

  2. Influence of weed mat and surface sawdust mulch on soil nutrient availability and soil chemical properties under organic blueberry production

    Science.gov (United States)

    Weed control represents one of the most important cultural management aspects for organic blueberry production. Two of the most common ways to control weeds in blueberries is by the use of surface sawdust mulch or by landscape fabric, often referred to as weed mat. Soil temperature and soil moisture...

  3. Carbon Dioxide Fluxes and Concentrations in a Cotton Field in Northwestern China: Effects of Plastic Mulching and Drip Irrigation

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-Guo; ZHANG Run-Hua; WANG Xiu-Jun; WANG Jie-Ping; ZHANG Cui-Ping; TIAN Chang-Yan

    2011-01-01

    In northwestern China, there has been a change from traditional cultivation system (TC) with no mulching and flood irrigation to a more modern cultivation system (MC) using plastic film mulching with drip irrigation. A field study was conducted to compare soil CO2 concentrations and soil surface CO2 fluxes between TC and MC systems during a cotton growing season. CO2 concentrations in the soil profile were higher in the MC system (3 107-9212 μL L-1) than in the TC system (1 275-8994 μL L-1) but the rate of CO2 flux was lower in the MC system. Possible reasons for this included decreased gas diffusion and higher soil moisture due to the mulching cover in the MC system, and the consumption of soil CO2 by weathering reactions. Over the whole cotton growing season,accumulated rates of CO2 flux were 300 and 394 g C m-2 for the MC and TC systems, respectively. When agricultural practices were converted from traditional cultivation to a plastic film mulching system, soil CO2 emissions could be reduced by approximately 100 g C m-2 year-1 in agricultural lands in arid and/or semi-arid areas of northern and northwestern China.

  4. [Influence of mulching management on the relationships between foliar non-structural carbohydrates and N, P concentrations in Phyllostachys violascens stand].

    Science.gov (United States)

    Guo, Zi-wu; Hu, Jun-jing; Yang, Qing-ping; Li, Ying-chun; Chen, Shuang-lin; Chen, Wei-jun

    2015-04-01

    To understand the physiological adaptive mechanism of Phyllostachys violascens to intensive mulching management, the effect of mulching management (CK, 1, 3 and 6 years) on the concentrations and ratios of non-structural carbohydrates (NSC), nitrogen (N) and phosphorus (P) in bamboo foliage, and their stoichiometry was investigated. The results showed the concentrations of NSC and soluble sugar increased, while the starch content and N/P decreased markedly in bamboo stand with 1-year mulching, compared to CK stand, which suggested the N limitation to bamboo growth was strengthened. Foliar soluble sugar content decreased significantly, while the starch content increased dramatically, and the NSC content by per unit mass of N and P reached the maximum in the bamboo stand with 3-year mulching, compared to all other treatments. Foliar NSC and soluble sugar contents decreased significantly, while foliar starch content and N/P increased dramatically in the stand with 6-year mulching, which suggested the P limitation to bamboo growth was strengthened. Foliar NSC content was positively correlated with N and P concentrations in a short-term mulching management stand (≤ 3 years), while showed negative relationship with N/P. The foliar starch content in the stand with 6-year mulching was negatively correlated with N and P contents, while was positively correlated with N/P. The results indicated that short-term mulching management accelerated the accumulation of soluble sugar and decomposition of starch in foliage, thus the growth and activity of Ph. violascens was enhanced greatly. Long-term mulching management promoted the starch accumulation, which led to the transition from N limitation to P limitation for bamboo growth. In summary, long-term (6 years) mulching management caused the decrease of growth and activity of Ph. violascens dramatically, thus enhancing the bamboo stand degradation. The utilization efficiency of N and P reached the highest in the stand with 3-year

  5. Yield responses and nutrient utilization with the use of chopped grass and clover material as surface mulches in an organic vegetable growing system

    OpenAIRE

    Riley, Hugh; Løes, Anne-Kristin; Hansen, Sissel; Dragland, Steinar

    2003-01-01

    Trials were performed with red beet and white cabbage in 1998-2001 to assess the effects on yields and nutrient utilization of surface mulch (chopped grass and/or red clover). No other nutrients were applied. Nitrogen (N), phosphorus (P) and potassium (K) contents were measured in mulch, saleable products and above-ground plant residues. A single mulch application of about 12 Mg DM ha-1 increased the yields of both crops significantly. Mean yields of saleable products were increased from 27 t...

  6. BIODEGRADABLE COATING FROM AGATHIS ALBA

    Directory of Open Access Journals (Sweden)

    NORYAWATI MULYONO

    2012-11-01

    Full Text Available The adhesive property of copal makes it as a potential coating onto aluminum foil to replace polyethylene. This research aimed to develop copal-based coating. The coating was prepared by extracting the copal in ethyl acetate and dipping the aluminium foil in ethyl acetate soluble extract of copal. The characterization of coating included its thickness, weight, thermal and chemical resistance, and biodegradation. The results showed that the coating thickness and weight increased as the copal concentration and dipping frequency increased. Thermal resistance test showed that the coating melted after being heated at 110°C for 30 min. Copal-based coating wasresistant to acidic solution (pH 4.0, water, and coconut oil, but was deteriorated in detergent 1% (w/v and basic solution (pH 10.0. Biodegradability test using Pseudomonas aeruginosa showed weight reduction of 76.82% in 30 days.

  7. Biodegradation of Polycyclic Aromatic Hydrocarbons

    OpenAIRE

    DEMİR, İsmail; DEMİRBAĞ, Zihni

    1999-01-01

    Polycylic aromatic hydrocarbons (PAHs), such as petroleum and petroleum derivatives, are widespread organic pollutants entering the environment, chiefly, through oil spills and incomplete combustion of fossil fuels. Since most PAHs are persist in the environment for a long period of time and bioaccumulate, they cause environmental pollution and effect biological equilibrium dramatically. Biodegradation of some PAHs by microorganisms has been biochemically and genetically investigated. Ge...

  8. Biodegradable lubricants for road vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, J. [Denmark Technical Univ., Lyngby (Denmark). Dept. of Mechanical Engineering

    2004-07-01

    This presentation outlined the characteristics of biolubricants and their use in vehicles. Experiments with compression ignition (CI) and spark ignition (SI) engines were also presented. Biolubes can be used in 4-stroke and 2-stroke engines, bearing compressors and hydraulic equipment. Studies have shown that biolubes do not cause unusual engine wear. They are produced from biomass, with the base material being vegetable oils and synthetic esters. Conventional lubricants are produced from fossil fuels, with the base material being mineral oils, polyglycol or synthetic ester. This presentation rated the characteristics of various lubricants in terms of viscosity temperature behaviour, low temperature behaviour, liquid range, oxidation stability, thermal stability, volatility, fire resistance, hydrolytic stability, corrosion protection, seal material compatibility, paints compatibility, miscibility with mineral oil, solubility of additives, lubricating properties, toxicity, and biodegradability. The environmental impacts of biolubes regarding emissions of carbon dioxide, nitrous oxide and particulate matter were discussed along with the impact of combining biolubes with alternative fuels. The future beneficial applications include outboard engines, off road vehicle engines and road vehicle engines. Currently, vegetable oil based biolubricants are 2 to 3 times more expensive than mineral based oils, and synthetic lubricants are even more expensive. It was suggested that future studies should examine the biodegradability of used lubricants, the performance of biodegradable lubricants, alternative fuels and fuel economy. tabs., figs.

  9. Engineering Flame Retardant Biodegradable Nanocomposites

    Science.gov (United States)

    He, Shan; Yang, Kai; Guo, Yichen; Zhang, Linxi; Pack, Seongchan; Davis, Rachel; Lewin, Menahem; Ade, Harald; Korach, Chad; Kashiwagi, Takashi; Rafailovich, Miriam

    2013-03-01

    Cellulose-based PLA/PBAT polymer blends can potentially be a promising class of biodegradable nanocomposites. Adding cellulose fiber reinforcement can improve mechanical properties of biodegradable plastics, but homogeneously dispersing hydrophilic cellulose in the hydrophobic polymer matrix poses a significant challenge. We here show that resorcinol diphenyl phosphates (RDP) can be used to modify the surface energy, not only reducing phase separation between two polymer kinds but also allowing the cellulose particles and the Halloysite clay to be easily dispersed within polymer matrices to achieve synergy effect using melt blending. Here in this study we describe the use of cellulose fiber and Halloysite clay, coated with RDP surfactant, in producing the flame retardant polymer blends of PBAT(Ecoflex) and PLA which can pass the stringent UL-94 V0 test. We also utilized FTIR, SEM and AFM nanoindentation to elucidate the role RDP plays in improving the compatibility of biodegradable polymers, and to determine structure property of chars that resulted in composites that could have optimized mechanical and thermal properties. Supported by Garcia Polymer Center and NSF Foundation.

  10. Radiation effects on biodegradable polyesters

    International Nuclear Information System (INIS)

    Poly(3-hydroxybutyrate) [P(3HB)] and its copolymer poly(3-hydroxybutyrate-co-3hydroxyvalerate) [P(3HB-co-3HV)] are microbial biodegradable polyesters produced by many types of bacteria. Poly(butylene succinate) (PBS) and poly(E-caprolactone) (PCL) are also biodegradable synthetic polyesters which have been commercialized. These thermoplastics are expected for wide usage in environmental protection and blocompatible applications. Radiation grafting of hydrophilic monomers onto many polymers, e.g., polyethylene and polypropylene has been studied mainly for biomedical applications. In the present study, radiation-induced graft polymerization of vinyl monomers onto PHB and P(3HB-co-3HV) was carried out and improvement of their properties was studied. Changes in the properties and biodegradability were compared with the degree of grafting. Radiation-induced crosslinking of PBS and PCL which relatively show thermal and irradiation stability was also carried out to improve their thermal stability or processability. Irradiation to PBS and PCL mainly resulted in crosslinking and characterization of these crosslinked polyesters was investigated

  11. The immediate effectiveness of barley straw mulch in reducing soil erodibility and surface runoff generation in Mediterranean vineyards.

    Science.gov (United States)

    Prosdocimi, Massimo; Jordán, Antonio; Tarolli, Paolo; Keesstra, Saskia; Novara, Agata; Cerdà, Artemi

    2016-03-15

    Soil and water loss in agriculture is a major problem throughout the world, and especially in Mediterranean areas. Non-conservation agricultural practices have further aggravated the situation, especially in vineyards, which are affected by one of the highest rates of soil loss among cultivated lands. Therefore, it is necessary to find the right soil practices for more sustainable viticulture. In this regard, straw mulching has proven to be effective in other crop and fire affected soils, but, nonetheless, little research has been carried out in vineyards. This research tests the effect of barley straw mulching on soil erosion and surface runoff on vineyards in Eastern Spain where the soil and water losses are non-sustainable. An experiment was setup using rainfall simulation tests at 55 mm h(-1) over 1h on forty paired plots of 0.24 m(2): twenty bare and twenty straw covered. Straw cover varied from 48 to 90% with a median value of 59% as a result of the application of 75 g of straw per m(2). The use of straw mulch resulted in delayed ponding and runoff generation and, as a consequence, the median water loss decreased from 52.59 to 39.27% of the total rainfall. The straw cover reduced the median sediment concentration in runoff from 9.8 to 3.0 g L(-1) and the median total sediment detached from 70.34 to 15.62 g per experiment. The median soil erosion rate decreased from 2.81 to 0.63 Mg ha(-1)h(-1) due to the straw mulch protection. Straw mulch is very effective in reducing soil erodibility and surface runoff, and this benefit was achieved immediately after the application of the straw. PMID:26789370

  12. Perforating Thin Metal Sheets

    Science.gov (United States)

    Davidson, M. E.

    1985-01-01

    Sheets only few mils thick bonded together, punched, then debonded. Three-step process yields perforated sheets of metal. (1): Individual sheets bonded together to form laminate. (2): laminate perforated in desired geometric pattern. (3): After baking, laminate separates into individual sheets. Developed for fabricating conductive layer on blankets that collect and remove ions; however, perforated foils have other applications - as conductive surfaces on insulating materials; stiffeners and conductors in plastic laminates; reflectors in antenna dishes; supports for thermal blankets; lightweight grille cover materials; and material for mockup of components.

  13. Biodegradation of high molecular weight polylactic acid

    OpenAIRE

    Stloukal, Petr; Koutný, Marek; Sedlařík, Vladimír; Kucharczyk, Pavel

    2012-01-01

    Polylactid acid seems to be an appropriate replacement of conventional non-biodegradable synthetic polymer primarily due to comparable mechanical, thermal and processing properties in its high molecular weight form. Biodegradation of high molecular PLA was studied in compost for various forms differing in their specific surface area. The material proved its good biodegradability under composting conditions and all investigated forms showed to be acceptable for industrial composting. Despite e...

  14. Biodegradable materials as foundry moulding sands binders

    OpenAIRE

    K. Major-Gabryś

    2015-01-01

    The aim of this article is to show the possibility of using biodegradable materials as part of the composition of foundry moulding and core sand binders. Research shows that moulding sands with biodegradable materials selected as binders are not only less toxic but are also better suited to mechanical reclamation than moulding sands with phenol-furfuryl resin. The use of biodegradable materials as additives to typical synthetic resins can result in their decreased toxicity and improved abilit...

  15. Biodegradable materials as foundry moulding sands binders

    Directory of Open Access Journals (Sweden)

    K. Major - Gabryś

    2015-07-01

    Full Text Available The aim of this article is to show the possibility of using biodegradable materials as part of the composition of foundry moulding and core sand binders. Research shows that moulding sands with biodegradable materials selected as binders are not only less toxic but are also better suited to mechanical reclamation than moulding sands with phenol-furfuryl resin. The use of biodegradable materials as additives to typical synthetic resins can result in their decreased toxicity and improved ability to reclamation as well as in accelerated biodegradation of binding material leftovers of mechanical reclamation.

  16. Infertility Fact Sheet

    Science.gov (United States)

    ... Home > ePublications > Our ePublications > Infertility fact sheet ePublications Infertility fact sheet This information in Spanish (en español) ... to the fallopian tube instead of the uterus. Gamete intrafallopian transfer (GIFT) involves transferring eggs and sperm into the ...

  17. Ice sheet in peril

    DEFF Research Database (Denmark)

    Hvidberg, Christine Schøtt

    2016-01-01

    Earth's large ice sheets in Greenland and Antarctica are major contributors to sea level change. At present, the Greenland Ice Sheet (see the photo) is losing mass in response to climate warming in Greenland (1), but the present changes also include a long-term response to past climate transitions...

  18. Landfill cover revegetation using organic amendments and cobble mulch in the arid southwest

    Energy Technology Data Exchange (ETDEWEB)

    AGUILAR,RICHARD; DWYER,STEPHEN F.; REAVIS,BRUCE A.; NEWMAN,GRETCHEN CARR; LOFTIN,SAMUEL R.

    2000-02-01

    Cobble mulch and composted biosolids, greenwaste, and dairy manure were added to arid soil in an attempt to improve plant establishment and production, minimize erosion, increase evapotranspiration, and reduce leaching. Twenty-four plots (10 x 10 m) were established in a completely randomized block design (8 treatments, 3 plots per treatment). Treatments included (1) non-irrigated control, (2) irrigated control, (3) non-irrigated greenwaste compost (2.5 yd{sup 3} per plot), (4) irrigated greenwaste compost (5 yd{sup 3} per plot), (5) non-irrigated biosolids compost (2.5 yd{sup 3} per plot), (6) irrigated biosolids compost (5 yd{sup 3} per plot), (7) cobble-mulch, and (8) non-irrigated dairy manure compost (2.5 yd{sup 3} per plot). Soil samples were collected from each plot for laboratory analyses to assess organic matter contents, macro-nutrient levels and trace metal contents, and nitrogen mineralization potential. All plots were seeded similarly with approximately equal portions of cool and warm season native grasses. The organic composts (greenwaste, biosolids, dairy manure) added to the soils substantially increased soil organic matter and plant nutrients including total nitrogen and phosphorus. However, the results of a laboratory study of the soils' nitrogen mineralization potential after the application of the various composts showed that the soil nitrogen-supplying capability decreased to non-amended soil levels by the start of the second growing season. Thus, from the standpoint of nitrogen fertilizer value, the benefits of the organic compost amendments appear to have been relatively short-lived. The addition of biosolids compost, however, did not produce significant changes in the soils' copper, cadmium, lead, and zinc concentrations and thus did not induce adverse environmental conditions due to excessive heavy metal concentrations. Supplemental irrigation water during the first and second growing seasons did not appear to increase plant

  19. Integrating a mini catchment with mulching for soil water management in a sloping jujube orchard on the semiarid Loess Plateau of China

    Directory of Open Access Journals (Sweden)

    H. C. Li

    2015-11-01

    Full Text Available Conserving more soil water is of great importance to the success of arid and semiarid orchards. On the hilly areas of the Loess Plateau of China, mini catchments, named fish-scale pits, are widely used in orchards for collecting surface runoff to infiltrate more soil water. However, the flat surface inside fish-scale pits would increase soil evaporation during non-rainfall periods. Therefore, we integrated fish-scale pits with mulching, a popular meaning to reduce soil evaporation, to test whether this integration could improve soil water conservation. The results showed that soil water deficit was observed for all treatments. However, soil water deficit was further intensified in the dry month. An index was used to represent the soil water supply from rainfall infiltration denoted WS. For the fish-scale pit with branch mulching treatment in the entire soil profile, the compensation degree of SWS were greater than 0. However, the CK treatment showed negative values in the 40–180 cm. In conclusion, integrating fish-scale pits with mulching could conserve significantly more soil water by increasing infiltration and decreasing evaporation compared to fish-scale pits alone. Since the mulching branches were trimmed jujube branches, the integration of fish-scale pit with branch mulching is recommended in jujube orchards in order to both preserve more soil water and reduce the cost of mulching materials.

  20. The Effects of Rape Residue Mulching on Net Global Warming Potential and Greenhouse Gas Intensity from No-Tillage Paddy Fields

    Science.gov (United States)

    Zhang, Zhi-Sheng; Cao, Cou-Gui; Guo, Li-Jin; Li, Cheng-Fang

    2014-01-01

    A field experiment was conducted to provide a complete greenhouse gas (GHG) accounting for global warming potential (GWP), net GWP, and greenhouse gas intensity (GHGI) from no-tillage (NT) paddy fields with different amounts of oilseed rape residue mulch (0, 3000, 4000, and 6000 kg dry matter (DM) ha−1) during a rice-growing season after 3 years of oilseed rape-rice cultivation. Residue mulching treatments showed significantly more organic carbon (C) density for the 0–20 cm soil layer at harvesting than no residue treatment. During a rice-growing season, residue mulching treatments sequestered significantly more organic C from 687 kg C ha−1 season−1 to 1654 kg C ha−1 season−1 than no residue treatment. Residue mulching significantly increased emissions of CO2 and N2O but decreased CH4 emissions. Residue mulching treatments significantly increased GWP by 9–30% but significantly decreased net GWP by 33–71% and GHGI by 35–72% relative to no residue treatment. These results suggest that agricultural economic viability and GHG mitigation can be achieved simultaneously by residue mulching on NT paddy fields in central China. PMID:25140329

  1. The contribution of mulches to control high soil erosion rates in vineyards in Eastern Spain

    Science.gov (United States)

    Cerdà, Artemi; Jordán, Antonio; Zavala, Lorena; José Marqués, María; Novara, Agata

    2014-05-01

    Soil erosion take place in degraded ecosystem where the lack of vegetation, drought, erodible parent material and deforestation take place (Borelli et al., 2013; Haregeweyn et al., 2013; Zhao et al., 2013). Agriculture management developed new landscapes (Ore and Bruins, 2012) and use to trigger non-sustainable soil erosion rates (Zema et al., 2012). High erosion rates were measured in agriculture land (Cerdà et al., 2009), but it is also possible to develop managements that will control the soil and water losses, such as organic amendments (Marqués et al., 2005), plant cover (Marqués et al., 2007) and geotextiles (Giménez Morera et al., 2010). The most successful management to restore the structural stability and the biological activity of the agriculture soil has been the organic mulches (García Orenes et al; 2009; 2010; 2012). The straw mulch is also very successful on bare fire affected soil (Robichaud et al., 2013a; 2013b), which also contributes to a more stable soil moisture content (García-Moreno et al., 2013). The objective of this research is to determine the impact of two mulches: wheat straw and chipped branches, on the soil erosion rates in a rainfed vineyard in Eastern Spain. The research site is located in the Les Alcusses Valley within the Moixent municipality. The Mean annual temperature is 13 ºC, and the mean annual rainfall 455 mm. Soil are sandy loam, and are developed at the foot-slope of a Cretaceous limestone range, the Serra Grossa range. The soils use to be ploughed and the features of soil erosion are found after each thunderstorm. Rills are removed by ploughing. Thirty rainfall simulation experiments were carried out in summer 2011 during the summer drought period. The simulated rainfall lasted during 1 hour at a 45 mmh-1 intensity on 1 m2 plots (Cerdà and Doerr, 2010; Cerdà and Jurgensen 2011). Ten experiments were carried out on the control plots (ploughed), 10 on straw mulch covered plots, and 10 on chipped branches covered

  2. Can growth-days predict the crop coefficient of cotton under mulched drip irrigation?

    Science.gov (United States)

    Yang, Pengju; Tian, Fuqiang; Hu, Hongchang; Zhang, Zhi; Dai, Chao

    2015-04-01

    Mulched drip irrigation (MDI) has now become popular in arid and semi-arid areas like Tarim River basin located in northwest of China. It has the advantages of saving water as well as increasing crop yield. As an important cash crop, cotton is widely planted in Tarim basin that usually adopts MDI. Irrigation management requires prediction of evapotranspiration (ET). It is usually calculated by FAO-56 method, in which the crop coefficient (Kc) is a necessary parameter needed to determined a prior. Theoretically the crop characteristics like LAI can serve as a direct indicator to determine Kc. Practically two other indicators of growing-degree-day (GDD) and growth-day (GD) are also used to determine Kc. In this study a 3-year experiment was conducted to quantify the weekly ETc and develop a crop coefficient (Kc) model for mulched drip-irrigated cotton based on eddy covariance observation. Two polynomial models were developed to predict the Kc as a function of growth days (r2=0.95) and growing degree-day (GDD) (r2=0.96) in the growth stage after seeding. A logarithmic function (r2=0.87) was used to describe the Kc variability with LAI increase. The results showed that both the three models fitted well with the Kc and the LAI values could fit the Kc well before the end growth stage. The LAI can better simulate Kc with daily step, but with weekly step the accuracy of LAI is lower than the other two variables. Our results showed that the growth-day is a reliable indicator to predict the cotton Kc under MDI, which provide a basis for transpiration modeling in cotton fields.

  3. Biodegradation kinetics at low concentrations (

    DEFF Research Database (Denmark)

    Toräng, Lars; Albrechtsen, Hans-Jørgen; Nyholm, Niels

    2000-01-01

    Aerobic biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in groundwater added sediment fines. At concentrations at or below 1 mu g/L of 2,4-D degradation kinetic was of true first order without significant growth of specific degraders and with half-life for mineralization in the...... order of 200 days. Higher concentrations of 2,4-D resulted in a grossly overestimate of the actual degradation rate for concentrations characteristic for Danish found in groundwater....

  4. Crushing pretreatment parameter optimization of soybean straw used as raw material of mulch%用于地膜原料的大豆秸秆粉碎预处理工艺参数优化

    Institute of Scientific and Technical Information of China (English)

    刘爽; 房欣; 张颖; 陈泓睿; 陈海涛

    2015-01-01

    为了满足植物纤维制取机对大豆秸秆原料长度的要求,采用改进的揉切式粉碎机对大豆秸秆进行预处理,选取揉切机的主轴转速、喂入量以及秸秆的含水率为试验因素,以大豆秸秆粉碎长度为响应函数,对大豆秸秆原料的预处理工艺参数进行了组合试验研究。结果表明:1)各因素对于秸秆粉碎长度影响的贡献率从高到低排序为主轴转速、含水率和喂入量;2)预处理工艺的最优参数组合为喂入量168 kg/h、大豆秸秆含水率处于36%~58%、揉切机主轴转速处于1100~1300 r/min。在此工艺参数条件下,大豆秸秆粉碎长度分布符合植物纤维制取机所要求的70~85 mm的理想范围。研究结果为完善植物纤维地膜制造工艺体系提供了参考。%Recently, a large amount of soybean straw was treated as waste and burned, which caused serious pollution. At the same time, for increasing the grain yield, the plastic mulch was applied widely in China which caused serious white pollution. Soybean straw was an excellent raw material of non-wood fiber, and manufacturing biodegradable mulch of soybean straw fiber could not only reduce the pollution, but also raise the value of soybean straw. Before the manufacturing of biodegradable mulch, the raw soybean straw need crushing pretreatment. There have been many domestic and international researches about the equipment of straw crushing. However, these equipments are mainly used for the preparation of straw returning, feeding or the formation of biomass solid fuel, and the straw crushing length is usually too short. According to the requirement of the plant fiber preparing machine, straw crushing length of 70- 85 mm is suitable for manufacturing soybean straw fiber mulch. As there is no special crushing equipment used for preparation raw material of straw fiber mulch, the existing rubbing and cutting machine was improved to process soybean straw with crushing

  5. Biodegradation and toxicological evaluation of lubricant oils

    Directory of Open Access Journals (Sweden)

    Ivo Shodji Tamada

    2012-12-01

    Full Text Available The aim of this work was to compare different toxicity levels of lubricant oils. The tests were performed using the earthworm (Eisenia andrei, arugula seeds (Eruca sativa and lettuce seeds (Lactuca sativa, with three types of contaminants (mineral lubricant oil, synthetic lubricant oil and used lubricant oil for various biodegradation periods in the soil. The toxicity tests indirectly measured the biodegradation of the contaminants. The samples were analyzed at t0, t60, t120 and t180 days of biodegradation. The used lubricant oil was proved very toxic in all the tests and even after biodegradation its toxicity was high. The mineral and synthetic oils were biodegraded efficiently in the soil although their toxicity did not disappear completely after 180 days.

  6. Algebra task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 3-5, our State Standards-based combined resource meets the algebraic concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are opportunities for problem-solving, patterning, algebraic graphing, equations and determining averages. The combined task & drill sheets

  7. Algebra task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 6-8, our State Standards-based combined resource meets the algebraic concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are opportunities for problem-solving, patterning, algebraic graphing, equations and determining averages. The combined task & drill sheets

  8. Modelling the impact of climatic conditions and plant species on the nitrogen release from mulch of legumes at the soil surface

    Science.gov (United States)

    Gaudinat, Germain; Lorin, Mathieu; Valantin-morison, Muriel; Garnier, Patricia

    2015-04-01

    Cover crops provide multiple services to the agro ecosystem. Among them, the use of legumes as cover crop is one of the solutions for limiting the use of herbicides, mineral fertilizers, and insecticides. However, the dynamic of mineralization is difficult to understand because of the difficulty of measuring nitrogen release from mulch in field. Indeed, residues are degraded at the soil surface as mulch, while the nitrogen uptake by the main crop occurred simultaneously in the soil. This work aims to study the dynamics of nitrogen mineralization from legume residues through i) the use of a model able to describe the physical and biological dynamic of mulch and ii) a data set from a field experiment of intercropping systems "oilseed rape-legumes" from different species (grass pea, lentil, Berseem clover, field pea, vetch). The objective of the simulations is to identify the variations of expected quantities of nitrogen from different legumes. The soil-plant model of mulch decomposition PASTIS-Mulch was used to determine the nitrogen supply from mulch available for rapeseed. These simulation results were compared to the data collected in the experimental field of Grignon (France). We performed analyzes of biochemical and physical characteristics of legume residues and monitored the evolution of mulches (moisture, density, cover surface, biomass) in fields. PASTIS simulations of soil temperature, soil moisture, mulch humidity and mulch decomposition were close to the experimental results. The PASTIS model was suitable to simulate the dynamic of legume mulches in the case of "rape - legume" associations. The model simulated nitrogen restitution of aerial and root parts. We found a more rapid nitrogen release by grass pea than other species. Vetch released less nitrogen than the other species. The scenarios for climate conditions were : i) a freezing in December that causes the destruction of plants, or a destruction by herbicide in March, ii) a strong or a weak rainy

  9. Agronomic performance of common bean in straw mulch systems and topdressing nitrogen rates in no-tillage

    OpenAIRE

    Tatiana Pagan Loeiro da Cunha; Fábio Luiz Checchio Mingotte; Antonio Carlos de Almeida Carmeis Carmeis Filho; Fernando Marcelo Chiamolera; Leandro Borges Lemos; Domingos Fornasieri Filho

    2015-01-01

    ABSTRACTIn no-tillage systems, straw coverage on soil surface is the key to success, and the choice of crops for rotation is crucial to achieve the sustainability and quality that conservation agriculture requires. The objective of this study was to evaluate the agronomic performance of the common bean cultivar IAC Formoso sown in succession to three straw mulch systems (corn alone, corn/Urochloa ruziziensisintercrop and U. ruziziensisalone) and topdress nitrogen rates (0; 40; 80; 120 and 160...

  10. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    Directory of Open Access Journals (Sweden)

    A. D. Chukalla

    2015-07-01

    Full Text Available Consumptive water footprint (WF reduction in irrigated crop production is essential given the increasing competition for fresh water. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET and yield (Y and thus the consumptive WF of crops (ET/Y. The management practices are: four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD; four irrigation strategies (full (FI, deficit (DI, supplementary (SI and no irrigation; and three mulching practices (no mulching, organic (OML and synthetic (SML mulching. Various cases were considered: arid, semi-arid, sub-humid and humid environments; wet, normal and dry years; three soil types; and three crops. The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching. The average reduction in the consumptive WF is: 8–10 % if we change from the reference to drip or SSD; 13 % when changing to OML; 17–18 % when moving to drip or SSD in combination with OML; and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow is lower.

  11. Towards identification of novel legume species of potential interest as cover crops and living mulches for the North Africa region.

    OpenAIRE

    Udupa , S. M.; Elhaddoury , J.; Krimi Bencheqroun , S; Thami-Alami, I.; Henkrar, F.; Baresel, J.P.; Finckh, M.R.

    2014-01-01

    Subsidiary crops (SC) grown either as cover crops (CC) preceding or following the main crops, or as living mulches (LM) together with the main crops can deliver multiple ecological services within farming systems. These include increasing the duration of soil cover in the rotation, increasing plant and microbial diversity, improving plant health, soil health and fertility, minimizing the use of tillage and agrochemicals, enhancing biological N fixation and soil C content, and reducing water d...

  12. Soil physical characteristics and yield of wheat and maize as affected by mulching materials and sowing methods

    Directory of Open Access Journals (Sweden)

    Syed Shahid Hussain Shah, Anwar-Ul-Hassan, Abdul Ghafoor

    2013-05-01

    Full Text Available Soil physical degradation due to agriculture activity is a pressing issue in Pakistan causing reduction in crop yields. The study was conducted to assess the effects of two sowing methods and two mulching materials on soil physical characteristics and yields of wheat and maize during 2008-10 at Faisalabad, Pakistan. Results showed that Bed sowing method along with wheat straw mulch increased Leaf Area Index of wheat by 5 to 16%, and of maize by 4 to 14% compared with other treatments. This treatment also produced maximum 1000-grain weight (50.5 g of wheat and maize (439.2g as compared to flat sowing method where no mulch was applied. The highest grain yields of wheat (5017 kg ha-1 and maize (10.6 Mg ha-1 were recorded in Bed sowing + wheat straw mulch plots. Bed sowing alone decreased bulk density by 4% at 0-15 cm soil depth and 13.7% less soil penetration resistance (788.2 kPa was noted. About 23.0% higher soil organic carbon contents (4.2 g kg-1 at 0-15 cm soil depth, 39.1% higher field saturated hydraulic conductivity (24.3 mm hr-1 and 14.2% higher infiltration rate (58.5 mm hr-1 were recorded compared to flood irrigated flat sowing. Furrow irrigated raised bed technique was found to be environment friendly in combination with farm manure compared to wheat straw having enhanced soil organic carbon contents.

  13. Effects of living mulches or residue amendments on soil microbial properties in direct seeded cropping systems of Madagascar

    OpenAIRE

    Rabary, B.; Sall, Saidou; Letourmy, P.; Husson, O.; Ralambofetra, E.; Moussa, N.; Chotte, Jean-Luc

    2008-01-01

    There is growing recognition for the need to study the impact of agricultural land uses on biological and biochemical properties of soils. In Madagascar, cropping systems based on direct seeding with permanent vegetation cover provide a new means for sustainable agriculture to protect the environment and make the most of natural resources. This study assessed the effects of different direct seeding mulch-based cropping systems on soil microbial biomass and activities. The soil was andic Dystr...

  14. Effect of Direct Seeding Mulch-Based Systems on Soil Carbon Storage and Macrofauna in Central Brazil

    OpenAIRE

    Eric Blanchart; Martial Bernoux; Xavier Sarda; Marcos Siqueira Neto; Carlos C. Cerri; Marisa Piccolo; Jean-marie Douzet; Eric Scopel; Christian Feller

    2007-01-01

    Soils represent a large carbon pool, approximately 1500 Gt, equivalent to almost three times the quantity stored in terrestrial biomass and twice the amount stored in the atmosphere. Any modification of land-use or land management can induce variations in soil carbon stocks, even in agricultural systems that are perceived to be in a steady state. These modifications also alter soil macrofauna that is known to affect soil carbon dynamics. Direct seeding Mulch-based Cropping (DMC) systems with ...

  15. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    Science.gov (United States)

    Chukalla, A. D.; Krol, M. S.; Hoekstra, A. Y.

    2015-12-01

    Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and thus the consumptive WF of crops (ET / Y). The management practices are four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD)), four irrigation strategies (full (FI), deficit (DI), supplementary (SI) and no irrigation), and three mulching practices (no mulching, organic (OML) and synthetic (SML) mulching). Various cases were considered: arid, semi-arid, sub-humid and humid environments in Israel, Spain, Italy and the UK, respectively; wet, normal and dry years; three soil types (sand, sandy loam and silty clay loam); and three crops (maize, potato and tomato). The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching). The average reduction in the consumptive WF is 8-10 % if we change from the reference to drip or SSD, 13 % when changing to OML, 17-18 % when moving to drip or SSD in combination with OML, and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow

  16. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lihui [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Zhang, Yongming, E-mail: zhym@shnu.edu.cn [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Bai, Qi; Yan, Ning; Xu, Hua [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Rittmann, Bruce E. [Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, AZ 85287-5701 (United States)

    2015-04-28

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA.

  17. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    International Nuclear Information System (INIS)

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA

  18. HRSA Data Fact Sheets

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Health Resources and Services Administration (HRSA) Data Fact Sheets provide summary data about HRSA’s activities in each Congressional District, County, State,...

  19. Polarised light sheet tomography.

    Science.gov (United States)

    Reidt, Sascha L; O'Brien, Daniel J; Wood, Kenneth; MacDonald, Michael P

    2016-05-16

    The various benefits of light sheet microscopy have made it a widely used modality for capturing three-dimensional images. It is mostly used for fluorescence imaging, but recently another technique called light sheet tomography solely relying on scattering was presented. The method was successfully applied to imaging of plant roots in transparent soil, but is limited when it comes to more turbid samples. This study presents a polarised light sheet tomography system and its advantages when imaging in highly scattering turbid media. The experimental configuration is guided by Monte Carlo radiation transfer methods, which model the propagation of a polarised light sheet in the sample. Images of both reflecting and absorbing phantoms in a complex collagenous matrix were acquired, and the results for different polarisation configurations are compared. Focus scanning methods were then used to reduce noise and produce three-dimensional reconstructions of absorbing targets. PMID:27409945

  20. Global ice sheet modeling

    International Nuclear Information System (INIS)

    The University of Maine conducted this study for Pacific Northwest Laboratory (PNL) as part of a global climate modeling task for site characterization of the potential nuclear waste respository site at Yucca Mountain, NV. The purpose of the study was to develop a global ice sheet dynamics model that will forecast the three-dimensional configuration of global ice sheets for specific climate change scenarios. The objective of the third (final) year of the work was to produce ice sheet data for glaciation scenarios covering the next 100,000 years. This was accomplished using both the map-plane and flowband solutions of our time-dependent, finite-element gridpoint model. The theory and equations used to develop the ice sheet models are presented. Three future scenarios were simulated by the model and results are discussed

  1. Ovarian Cancer Fact Sheet

    Science.gov (United States)

    ... widgets/current/fahc.html/ Search Share Embed Ovarian cancer fact sheet Ovarian cancer is cancer that begins in the ovaries. ... make female hormones and produce a woman's eggs. Ovarian cancer is a serious cancer that is more ...

  2. Trace element mobility in a contaminated soil two years after field-amendment with a greenwaste compost mulch

    International Nuclear Information System (INIS)

    Application of greenwaste compost to brownfield land is increasingly common in soil and landscape restoration. Previous studies have demonstrated both beneficial and detrimental effects of this material on trace element mobility. A pot experiment with homogenised soil/compost investigated distribution and mobility of trace elements, two years after application of greenwaste compost mulch to shallow soils overlying a former alkali-works contaminated with Pb, Cu and As (∼900, 200 and 500 mg kg-1, respectively). Compost mulch increased organic carbon and Fe in soil pore water, which in turn increased As and Sb mobilization; this enhanced uptake by lettuce and sunflower. A very small proportion of the total soil trace element pool was in readily-exchangeable form (<0.01% As, <0.001% other trace elements), but the effect of compost on behaviour of metals was variable and ambiguous. It is concluded that greenwaste compost should be applied with caution to multi-element contaminated soils. - Arsenic solubility and bioavailability increases in soil two years after application of greenwaste compost mulch.

  3. Effects of mulching tolerant plant straw on soil surface on growth and cadmium accumulation of Galinsoga parviflora.

    Directory of Open Access Journals (Sweden)

    Lijin Lin

    Full Text Available Pot and field experiments were conducted to study the effects of mulching with straw of cadmium (Cd tolerant plants (Ranunculus sieboldii, Mazus japonicus, Clinopodium confine and Plantago asiatica on growth and Cd accumulation of Galinsoga parviflora in Cd-contaminated soil. In the pot experiment, mulching with M. japonicus straw increased the root biomass, stem biomass, leaf biomass, shoot biomass, plant height and activities of antioxidant enzymes (superoxide dismutase, peroxidase and catalase of G. parviflora compared with the control, whereas mulching with straws of R. sieboldii, C. confine and P. asiatica decreased these parameters. Straws of the four Cd-tolerant plants increased the Cd content in roots of G. parviflora compared with the control. However, only straws of M. japonicus and P. asiatica increased the Cd content in shoots of G. parviflora, reduced the soil pH, and increased the soil exchangeable Cd concentration. Straw of M. japonicus increased the amount of Cd extraction in stems, leaves and shoots of G. parviflora by 21.11%, 29.43% and 24.22%, respectively, compared with the control, whereas straws of the other three Cd-tolerant plants decreased these parameters. In the field experiment, the M. japonicus straw also increased shoot biomass, Cd content in shoots, and amount of Cd extraction in shoots of G. parviflora compared with the control. Therefore, straw of M. japonicus can be used to improve the Cd extraction ability of G. parviflora from Cd-contaminated soil.

  4. Biodiesel Basics (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2014-06-01

    This fact sheet provides a brief introduction to biodiesel, including a discussion of biodiesel blends, which blends are best for which vehicles, where to buy biodiesel, how biodiesel compares to diesel fuel in terms of performance, how biodiesel performs in cold weather, whether biodiesel use will plug vehicle filters, how long-term biodiesel use may affect engines, biodiesel fuel standards, and whether biodiesel burns cleaner than diesel fuel. The fact sheet also dismisses the use of vegetable oil as a motor fuel.

  5. Are Graphene Sheets Stable?

    OpenAIRE

    Garcia, N.

    2007-01-01

    The answer to the title question is yes and the sheets exhibit diffraction peaks but may not have long range crystalline order. This is not a trivial question and answer and is immersing in the very active field now days of the study of properties of graphite and specially of graphene. This note is motivated in fact by a recent paper by Meyer et al (1) on the structure of suspended graphene sheets.

  6. Energy information sheets

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the public. The Energy Information Sheets was developed to provide general information on various aspects of fuel production, prices, consumption, and capability. Additional information on related subject matter can be found in other Energy Information Administration (EIA) publications as referenced at the end of each sheet.

  7. Graphene reinforced biodegradable poly(3-hydroxybutyrate-co-4-hydroxybutyrate nano-composites

    Directory of Open Access Journals (Sweden)

    V. Sridhar

    2013-04-01

    Full Text Available Novel biodegradable poly(3-hydroxybutyrate-co-4-hydroxybutyrate [PHBV]/graphene nanocomposites were prepared by solution casting. The thermal properties, crystallization behavior, microstructure, and fracture morphology of the composites were investigated. Scanning electron microscope (SEM results show that graphene layers are homogeneously dispersed in the polymer matrix. X-ray diffraction (XRD and dynamic scanning calorimetry (DSC studies show that the well dispersed graphene sheets act as nucleating agent for crystallization. Consequently, the mechanical properties of the composites have been substantially improved as evident from dynamic mechanical and static tensile tests. Differential thermal analysis (DTA showed an increase in temperature of maximum degradation. Soil degradation tests of PHBV/graphene nanocomposites showed that presence of graphene doesn’t interfere in its biodegradability.

  8. EFFECT OF DIFFERENT ORGANIC MULCHING MATERIALS ON SOIL PROPERTIES OF NA 7 ANOLA (EMBLICA OFFICINALIS GAERTN UNDER RAINFED CONDITION OF SHIWALIK FOOTHILLS OF HIMALAYAS INDIA

    Directory of Open Access Journals (Sweden)

    VIJAY KUMAR

    2014-06-01

    Full Text Available An experiment was conducted during 2009-2011 to assess the effected different organic mulches (Bajra straw, Maize straw, Palah leaves (Butea monosperma, Branker (Adhatoda vassica, Farmyard manure on soil properties in NA ‘7’ aonla (Emblica officinalis Gaertn. Different organic mulches significantly increased the soil organic carbon and nutrients. Soil properties were highest in FYM and lowest in control. In the present study the effect of mulching type on soil characters including soil pH, EC, OC, Available N, P and K was evaluated during two years. This research was conducted as randomized block design with four replications. In this study, soil pH, OC (organic carbon, EC, N, P and K in 0 to 15 cm soil depth was measured. Results showed that effect of type of mulch on soil pH and soil EC was not significant among all the treatments, while on OC (organic carbon, N, P and K was significant in all treatments. Farmyard manure mulch recorded highest soil organic carbon (6.60 and 6.80 g kg-1, Soil available nitrogen (238.00 and 239 kg ha-1, Soil available Phosphorus (20.12and 21.00 kg ha-1 and Soil available Potassium (169.92 and 179.48 kg ha-1 in 2009 and 2010 followed by branker (Adhatoda vassica. Maize straw mulch with 0-15 cm thickness has the highest reduction of soil pH and EC in all types of mulch. FYM with 0-15 cm thickness has the highest percentage of OC, N, P and K. Farmyard manure and Branker (Adhatoda vassica have the greatest effect on soil organic carbon and available nutrients.

  9. Biodegradable Metals From Concept to Applications

    CERN Document Server

    Hermawan, Hendra

    2012-01-01

    This book in the emerging research field of biomaterials covers biodegradable metals for biomedical applications. The book contains two main parts where each of them consists of three chapters. The first part introduces the readers to the field of metallic biomaterials, exposes the state of the art of biodegradable metals, and reveals its application for cardiovascular implants. It includes some fundamental aspects to give basic understanding on metals for further review on the degradable ones is covered in chapter one. The second chapter introduces the concept of biodegradable metals, it's st

  10. Biodegradation of surfactant bearing wastes

    International Nuclear Information System (INIS)

    In nuclear industry, during decontamination of protective wears and contaminated materials, detergents are employed to bring down the level of radioactive contamination within safe limits. However, the surfactant present in these wastes interferes in the chemical treatment process, reducing the decontamination factor. Biodegradation is an efficient and ecologically safe method for surfactant removal. A surfactant degrading culture was isolated and inoculated separately into simulated effluents containing 1% yeast extract and 5-100 ppm sodium lauryl sulphate (SLS) and 1% yeast extract and 5-100 ppm of commercial detergent respectively. The growth of the bacterial culture and the degradation characteristics of the surfactant in the above effluents were monitored under both dynamic and static conditions. (author). 6 refs., 6 figs., 1 tab

  11. New perspectives in plastic biodegradation.

    Science.gov (United States)

    Sivan, Alex

    2011-06-01

    During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution. PMID:21356588

  12. Engineered biosynthesis of biodegradable polymers.

    Science.gov (United States)

    Jambunathan, Pooja; Zhang, Kechun

    2016-08-01

    Advances in science and technology have resulted in the rapid development of biobased plastics and the major drivers for this expansion are rising environmental concerns of plastic pollution and the depletion of fossil-fuels. This paper presents a broad view on the recent developments of three promising biobased plastics, polylactic acid (PLA), polyhydroxyalkanoate (PHA) and polybutylene succinate (PBS), well known for their biodegradability. The article discusses the natural and recombinant host organisms used for fermentative production of monomers, alternative carbon feedstocks that have been used to lower production cost, different metabolic engineering strategies used to improve product titers, various fermentation technologies employed to increase productivities and finally, the different downstream processes used for recovery and purification of the monomers and polymers. PMID:27260524

  13. Biodegradation of halogenated organic compounds.

    Science.gov (United States)

    Chaudhry, G R; Chapalamadugu, S

    1991-03-01

    In this review we discuss the degradation of chlorinated hydrocarbons by microorganisms, emphasizing the physiological, biochemical, and genetic basis of the biodegradation of aliphatic, aromatic, and polycyclic compounds. Many environmentally important xenobiotics are halogenated, especially chlorinated. These compounds are manufactured and used as pesticides, plasticizers, paint and printing-ink components, adhesives, flame retardants, hydraulic and heat transfer fluids, refrigerants, solvents, additives for cutting oils, and textile auxiliaries. The hazardous chemicals enter the environment through production, commercial application, and waste. As a result of bioaccumulation in the food chain and groundwater contamination, they pose public health problems because many of them are toxic, mutagenic, or carcinogenic. Although synthetic chemicals are usually recalcitrant to biodegradation, microorganisms have evolved an extensive range of enzymes, pathways, and control mechanisms that are responsible for catabolism of a wide variety of such compounds. Thus, such biological degradation can be exploited to alleviate environmental pollution problems. The pathways by which a given compound is degraded are determined by the physical, chemical, and microbiological aspects of a particular environment. By understanding the genetic basis of catabolism of xenobiotics, it is possible to improve the efficacy of naturally occurring microorganisms or construct new microorganisms capable of degrading pollutants in soil and aquatic environments more efficiently. Recently a number of genes whose enzyme products have a broader substrate specificity for the degradation of aromatic compounds have been cloned and attempts have been made to construct gene cassettes or synthetic operons comprising these degradative genes. Such gene cassettes or operons can be transferred into suitable microbial hosts for extending and custom designing the pathways for rapid degradation of recalcitrant

  14. Robot automated EMPT sheet welding

    OpenAIRE

    Pasquale, Pablo; Schäfer, Ralph

    2012-01-01

    Many industrial applications require sheet to sheet or sheet to tube joints. The electromagnetic pulse technology is capable to produce these kinds of joints. In literature many examples of sheet to sheet solid state welding between similar and dissimilar metals are presented and analyzed in detail. However, the most of the presented welding applications, which are very focussed on the academic level, are simple specimens for example for tensile test. These specimens are usuall...

  15. The effect of mulching and soil compaction on fungi composition and microbial communities in the rhizosphere of soybean

    Science.gov (United States)

    Frac, M.; Siczek, A.; Lipiec, J.

    2009-04-01

    The soil environment is the habitat of pathogenic and saprotrophic microorganisms. The composition of the microbial community are related to biotic and abiotic factors, such as root exudates, crop residues, climate factors, mulching, mineral fertilization, pesticides introduction and soil compaction. The aim of the study was to determine the effect of the mulching and soil compaction on the microorganism communities in the rhizosphere soil of soybean. The studies were carried out on silty loam soil (Orthic Luvisol) developed from loess (Lublin, Poland). The experiment area was 192m2 divided into 3 sections consisted of 6 micro-plots (7m2). Three levels of soil compaction low, medium and heavy obtained through tractor passes were compared. The soil was compacted and loosened within seedbed layer 2 weeks before sowing. Soybean "Aldana" seeds were inoculated with Bradyrhizobium japonicum and were sown with interrow spacing of 0.3m. Wheat straw (as mulch) was uniformly spread on the half of each micro-plot at an amount of 0.5kg m-1 after sowing. Rhizosphere was collected three times during growing season of soybean. Microbiological analyses were conducted in 3 replications and included the determination of: the total number of bacteria and fungi, the number of bacteria Pseudomonas sp. and Bacillus sp., the genus identification of fungi isolated from rhizosphere of soybean. Results indicated a positive effect of mulching on the increase number of all groups of examined rhizosphere microorganisms (fungi, bacteria, Pseudomonas sp., Bacillus sp.). The highest number of the microorganisms was found in the low and medium compacted soil and markedly decreased in the most compacted soil. Relatively high number of antagonistic fungi (Penicillium sp., Trichoderma sp.) was recorded in the rhizosphere of low and medium compacted soil, particularly in mulched plots. The presence of these fungi can testify to considerable biological activity, which contributes to the improvement of

  16. Preparation and degradation mechanisms of biodegradable polymer: a review

    Science.gov (United States)

    Zeng, S. H.; Duan, P. P.; Shen, M. X.; Xue, Y. J.; Wang, Z. Y.

    2016-07-01

    Polymers are difficult to degrade completely in Nature, and their catabolites may pollute the environment. In recent years, biodegradable polymers have become the hot topic in people's daily life with increasing interest, and a controllable polymer biodegradation is one of the most important directions for future polymer science. This article presents the main preparation methods for biodegradable polymers and discusses their degradation mechanisms, the biodegradable factors, recent researches and their applications. The future researches of biodegradable polymers are also put forward.

  17. Integrating a mini catchment with mulching for soil water management in a sloping jujube orchard on the semiarid Loess Plateau of China

    Science.gov (United States)

    Li, Hongchen; Zhao, Xining; Gao, Xiaodong

    2015-04-01

    Conserving more soil water is of great importance to the success of arid and semiarid orchards. On the hilly areas of the Loess Plateau of China, mini catchments, named fish-scale pits, are widely used in orchards for collecting surface runoff to infiltrate more soil water. However, the flat surface inside fish-scale pits would increase soil evaporation during non-rainfall periods. Here we integrated fish-scale pits with mulching, a popular meanings to reduce soil evaporation, to test whether this integration could improve soil water conservation. To this end, we observed soil water in the 0-180 cm in a typical rain fed jujube orchard in the hilly region of the Loess Plateau. Four different treatments with three replicates of each were established including fish-scale pit with branch mulching (FB), fish-scale pit with straw mulching (FS), fish-scale pit without mulching (F) and no fish-scale pit and no mulching (CK). The results showed that the treatments FB, FS, and F increased soil water storages (SWS) in the 0-180 cm by 14.23%, 9.35% and 4.82%, respectively, compared to the CK during the growing season. It is noteworthy that the increases of SWS were mainly in the 0-100cm indicating relatively low levels of water was supplied by rainfall infiltration beneath. During the dry season (June), an apparent soil water deficit was observed for all treatments. Throughout the wet season (July and August) soil water was greatly compensated. However, soil water deficit occurred again in the dry month of September. An index was used to represent the soil water supply from rainfall infiltration denoted WS. During the growing season the FB and FS treatments showed positive WS in the whole profile while the F treatment showed positive values only in the 0-100 cm. However, positive WS values were only found in the 0-40 cm for the CK treatment. In conclusion, integrating fish-scale pits with branch/straw mulching could conserve significantly more soil water by increasing

  18. Biodegradable polymers: Which, when and why?

    Directory of Open Access Journals (Sweden)

    Kotwal V

    2007-01-01

    Full Text Available The plethora of drug therapies and types of drugs demand different formulations, fabrications conditions and release kinetics. No single polymer can satisfy all the requirements. Therefore there have been tremendous advances in area of biodegradable copolymers over the last 30 years. This article reviews current research on biodegradable polymers, focusing their potential as drug carries. The major classes of polymers are briefly discussed with regard to synthesis, properties and biodegradability, and known degradation modes and products are indicated based on studies reported in the literature. A vast majority of biodegradable polymers studied belongs to the polyester family, which includes polyglycolides and polylactides. Other degradable polymers such as polyorthoesters, polyanhydrides and polyphosphazenes are also discussed and their advantages and disadvantages are summarized.

  19. Biodegradable lubricants - ''the solution for future?''

    International Nuclear Information System (INIS)

    The environmental impact of lubricants use concern the direct effects from spills but also the indirect effects such as their lifetime and the emissions from thermal engines. The biodegradable performances and the toxicity are the environmental criteria that must be taken into account in the development and application of lubricants together with their technical performances. This paper recalls first the definition of biodegradable properties of hydrocarbons and the standardized tests, in particular the CEC and AFNOR tests. Then, the biodegradable performances of basic oils (mineral, vegetal, synthetic esters, synthetic hydrocarbons etc..), finite lubricants (hydraulic fluids..) and engine oils is analyzed according to these tests. Finally, the definition of future standards would take into account all the environmental characteristics of the lubricant: biodegradable performances, energy balance (CO2, NOx and Hx emissions and fuel savings), eco-toxicity and technical performances (wearing and cleanliness). (J.S.)

  20. Comparison of the effects of ploughing and mulching with straw on water economy in the groundnut-millet system in Senegal

    International Nuclear Information System (INIS)

    In Senegal water availability is very often the principal factor limiting crop yields, and it is necessary to develop techniques for making optimum use of the low rainfall. To this end a comparison was made of the effects on the water economy of (a) post-harvest oxen ploughing and (b) straw mulching with minimum tillage. A neutron probe and tensiometers were used to determine the water balance. It was found that mulching has no effect on water storage during the dry season, if it is not accompanied by a weed-control treatment, but does help to contain evaporation in the rainy season. On the other hand, ploughing reduces water losses in the dry season, and in the wet season helps to increase water uptake by the plant by stimulating root growth. In 1977, a very dry year, the yield of the groundnut plant was increased by 52% by ploughing as compared with a 27% increase from mulching and minimum tillage combined with weed-killing in the dry season; mulching and minimum tillage have no effect (on yield) if no weed-killing treatment is applied during the dry season. As straw mulching is in any case more difficult to practise than post-harvest ploughing in Senegalese agricultural conditions, the latter technique is obviously to be preferred for improving the utilization of available water by crops. (author)

  1. Biodegradation of cresol isomers in anoxic aquifers.

    OpenAIRE

    Smolenski, W J; Suflita, J M

    1987-01-01

    The biodegradation of o-, m-, and p-cresol was examined in material obtained from a shallow anaerobic alluvial sand aquifer. The cresol isomers were preferentially metabolized, with p-cresol being the most easily degraded. m-Cresol was more persistent than the para-isomer, and o-cresol persisted for over 90 days. Biodegradation of cresol isomers was favored under sulfate-reducing conditions (SRC) compared with that under methanogenic conditions (MC). Slurries that were acclimated to p-cresol ...

  2. Biodegradation and toxicological evaluation of lubricant oils

    OpenAIRE

    Ivo Shodji Tamada; Paulo Renato Matos Lopes; Renato Nallin Montagnolli; Ederio Dino Bidoia

    2012-01-01

    The aim of this work was to compare different toxicity levels of lubricant oils. The tests were performed using the earthworm (Eisenia andrei), arugula seeds (Eruca sativa) and lettuce seeds (Lactuca sativa), with three types of contaminants (mineral lubricant oil, synthetic lubricant oil and used lubricant oil) for various biodegradation periods in the soil. The toxicity tests indirectly measured the biodegradation of the contaminants. The samples were analyzed at t0, t60, t120 and t180 days...

  3. A mechanical switch device made of a polyimide-coated microfibrillated cellulose sheet

    Science.gov (United States)

    Couderc, S.; Ducloux, O.; Kim, B. J.; Someya, T.

    2009-05-01

    This paper covers innovative results on the development of an electrostatically actuated mechanical switch device made of a microfibrillated cellulose sheet coated with a thin polyimide layer. For microelectronic applications, biodegradable and biocompatible nanomaterials such as microfibrillated cellulose (MFC) have attracted attention. The studied MFC sheets reveal a fibrous-like morphology composed of cellulose nanofibres leading to a high surface roughness. Moreover, the porous microstructure and the hydrophilic nature of the MFC sheet induce poor dielectric properties. These shortcomings make MFC sheets relatively unsuitable for electronic applications. In order to overcome these drawbacks, both sides of the MFC sheet are coated with a thin polyimide layer, which greatly improves the dielectric properties, moisture sensitivity and sheet surface roughness. This new sheet is then patterned in order to be used as a substrate for the fabrication of a micromechanical switch. Gold electrodes are added onto the sheet for electrostatic actuation and switch detection. The pull-down voltage of this switch, defined as the actuation voltage needed to establish a contact between the free end of the cantilever beam and the substrate, is measured to be about 55 V.

  4. A mechanical switch device made of a polyimide-coated microfibrillated cellulose sheet

    International Nuclear Information System (INIS)

    This paper covers innovative results on the development of an electrostatically actuated mechanical switch device made of a microfibrillated cellulose sheet coated with a thin polyimide layer. For microelectronic applications, biodegradable and biocompatible nanomaterials such as microfibrillated cellulose (MFC) have attracted attention. The studied MFC sheets reveal a fibrous-like morphology composed of cellulose nanofibres leading to a high surface roughness. Moreover, the porous microstructure and the hydrophilic nature of the MFC sheet induce poor dielectric properties. These shortcomings make MFC sheets relatively unsuitable for electronic applications. In order to overcome these drawbacks, both sides of the MFC sheet are coated with a thin polyimide layer, which greatly improves the dielectric properties, moisture sensitivity and sheet surface roughness. This new sheet is then patterned in order to be used as a substrate for the fabrication of a micromechanical switch. Gold electrodes are added onto the sheet for electrostatic actuation and switch detection. The pull-down voltage of this switch, defined as the actuation voltage needed to establish a contact between the free end of the cantilever beam and the substrate, is measured to be about 55 V

  5. 日光温室不同覆盖模式对番茄产量和微环境的影响%Effects of Different Mulching Modes on Tomato Yield and Microenvironment in Solar Greenhouse

    Institute of Scientific and Technical Information of China (English)

    柴文臣; 张微

    2015-01-01

    To select out better mulching mode for the growth of greenhouse tomato, this paper studied effects of two different mulching modes (wheat straw mulching and plastic film mulching) on air humidity, air temperature, soil temperature, soil physical and chemical properties, tomato yield and agronomic characters in solar greenhouse. The results showed that, wheat straw mulching could effectively regulate soil physical and chemical properties, and significantly improve tomato yield and commercial characters compared with plastic film mulching. Therefore, wheat straw mulching was the appropriate mulching mode for greenhouse tomato production.%在日光温室条件下,研究了地膜覆盖和秸秆覆盖2种方式对温室空气湿度、空气温度、土壤温度、土壤理化性状、番茄产量和农艺性状的影响,筛选出有利于温室番茄生长的最佳覆盖模式。研究结果表明,秸秆覆盖能有效调节土壤的理化性状,该处理下的番茄商品性和产量与地膜覆盖处理的相比显著提高,是适宜日光温室番茄生长的覆盖方式。

  6. Biodegradability of Chlorinated Anilines in Waters

    Institute of Scientific and Technical Information of China (English)

    CHAO WANG; GUAN-GHUA LU; YAN-JIE ZHOU

    2007-01-01

    Objective To identify the bacteria tolerating chlorinated anilines and to study the biodegradability of o-chloroaniline and its coexistent compounds. Methods Microbial community of complex bacteria was identified by plate culture observation techniques and Gram stain method. Bacterial growth inhibition test was used to determine the tolerance of complex bacteria to toxicant. Biodegradability of chlorinated anilines was determined using domesticated complex bacteria as an inoculum by shaking-flask test. Results The complex bacteria were identified, consisting of Xanthomonas, Bacillus alcaligenes,Acinetobacter, Pseudomonas, and Actinomycetaceae nocardia. The obtained complex bacteria were more tolerant to o-chloroaniline than mixture bacteria in natural river waters. The effects of exposure concentration and inoculum size on the biodegradability of o-chloroaniline were analyzed, and the biodegradation characteristics of single o-chloroaniline and 2,4-dichloroaniline were compared with the coexistent compounds. Conclusion The biodegradation rates can be improved by decreasing concentration of compounds and increasing inoculum size of complex bacteria. When o-chloroaniline coexists with aniline, the latter is biodegraded prior to the former, and as a consequence the metabolic efficiency of o-chloroaniline is improved with the increase of aniline concentration. Meanwhile, when o-chloroaniline coexists with 2,4-dichloroaniline, the metabolic efficiency of 2,4-dichloroaniline is markedly improved.

  7. Living mulch strategy for organic cauliflower (Brassica oleracea L. production in central and southern Italy

    Directory of Open Access Journals (Sweden)

    Stefano Canali

    2015-06-01

    Full Text Available In sustainable agricultural systems, intercropping using living mulches (LM provides many beneficial ecosystem services. The objective of these two-year field experiments was to study the suitability of different LM options of burr medic (Medicago polymorpha L. var. anglona for organic cauliflower (Brassica oleracea L. cultivation in two sites under Mediterranean conditions. In central Italy (Experiment 1 contemporary and delayed (to crop sowings of LM were compared with a no-cover crop treatment, contrasting two local cauliflower cultivars and a F1 Hybrid. In southern Italy (Experiment 2 the sustainability of systems combining LM (anticipated and contemporary sowing compared with no-cover and organic fertilisation strategies was assessed. The aboveground biomasses dry weights of cauliflower crop (heads and residues, burr medic and weeds were separately determined. Results suggested that in Experiment 1 the LM was not able to smother weeds establishment and growth, as a consequence of early sowing, while cauliflower yield was reduced. Moreover, the genotypes behaviour was greatly influenced by the LM sowing times. In Experiment 2, irrespective of the agronomic practices applied, climatic conditions notably influenced cauliflower cultivation and also reduced the mean yield. Therefore, the recorded differences between the two experimental sites highlighted the need to tailor the LM strategies to the different environmental conditions.

  8. Safety advice sheets

    CERN Multimedia

    HSE Unit

    2013-01-01

    You never know when you might be faced with questions such as: when/how should I dispose of a gas canister? Where can I find an inspection report? How should I handle/store/dispose of a chemical substance…?   The SI section of the DGS/SEE Group is primarily responsible for safety inspections, evaluating the safety conditions of equipment items, premises and facilities. On top of this core task, it also regularly issues “Safety Advice Sheets” on various topics, designed to be of assistance to users but also to recall and reinforce safety rules and procedures. These clear and concise sheets, complete with illustrations, are easy to display in the appropriate areas. The following safety advice sheets have been issued so far: Other sheets will be published shortly. Suggestions are welcome and should be sent to the SI section of the DGS/SEE Group. Please send enquiries to general-safety-visits.service@cern.ch.

  9. Energy information sheets

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-02

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the general public. Written for the general public, the EIA publication Energy Information Sheets was developed to provide information on various aspects of fuel production, prices, consumption and capability. The information contained herein pertains to energy data as of December 1991. Additional information on related subject matter can be found in other EIA publications as referenced at the end of each sheet.

  10. Effects of tillage methods, corn residue mulch and n fertilizer levels on the wheat crop productivity under the rain fed condition of loess plateau china

    International Nuclear Information System (INIS)

    A 2 years study was conducted to assess the effects of different tillage methods (Chisel plough tillage, Zero-tillage, Rotary tillage and Mould board plough tillage), two mulch levels (M0 i.e. No corn residue mulch and M1 i.e. Corn residue mulch) and 5 N fertilizer levels (0, 80, 160, 240 and 320 kg N/ha) on the wheat crop productivity under the rain fed condition of Loess Plateau, China. Factorial experiment with three replications, having strip, split-split arrangement, with tillage methods in the main plots, mulch levels in sub- plots and N-fertilizer levels in the sub-sub plots was used for this study. Due to variations in rainfalls, during the year, 2010-11, maximum grain yields i.e. 6.58 t/ha and 6.72 t/ha were recorded in case of Zero tillage planting method and similarly in case of 80 kg N/ha, while during the cropping year 2011-12 equal grain yields were recorded in case of all tillage methods, however maximum grain yield (7.46 t /ha) was recorded in case of 320 kg N/ha, N fertilizer level. On two years average basis, maximum grain yields i.e. 6.75 t/ha and 6.80 t/ha were recorded in case of Zero tillage planting method and similarly in case of 80 kg N/ha as compared with the other tillage methods or N fertilizer levels. Use of mulch reduced > 40% weeds infestation. Economic analysis shows that Zero tillage and minimum use of N fertilizer according to the projected rainfalls along with the use of mulch are both economic and environmental friendly. (author)

  11. Pseudomonas - Fact Sheet

    OpenAIRE

    Public Health Agency

    2012-01-01

    Fact sheet on Pseudomonas, including:What is Pseudomonas?What infections does it cause?Who is susceptible to pseudomonas infection?How will I know if I have pseudomonas infection?How can Pseudomonas be prevented from spreading?How can I protect myself from Pseudomonas?How is Pseudomonas infection treated?

  12. Fact Sheet on Stress

    Science.gov (United States)

    ... items) NIMH (7 items) Share Fact Sheet on Stress Download PDF Download ePub Q&A on Stress for Adults: How it affects your health and ... to avoid more serious health effects. What is stress? Stress can be defined as the brain's response ...

  13. Ethanol Basics (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2015-01-01

    Ethanol is a widely-used, domestically-produced renewable fuel made from corn and other plant materials. More than 96% of gasoline sold in the United States contains ethanol. Learn more about this alternative fuel in the Ethanol Basics Fact Sheet, produced by the U.S. Department of Energy's Clean Cities program.

  14. CSS - Cascading Style Sheets

    OpenAIRE

    Martinelli, Massimo

    2009-01-01

    Curso "CSS - Cascading Style Sheets" sobre programación web con CSS para el "Máster doble competencia en ciencias informáticas y ciencias sociales" ("Master double competence in computer science and social science"). Proyecto TEMPUS JEP – 26235-2005

  15. THE INFLUENCE OF VERMISOL COMPLEX WATER-SOLUBLE FERTILIZER AND STRAW MULCHING OF ROW-SPACINGS FOR SOIL MOISTURE IN SWEET CORN GROWING MANAGEMENT

    OpenAIRE

    Sidorenko S. E.

    2015-01-01

    The article reveals issues concerning the experiments on application of complex water-soluble fertilizer and straw mulching of row-spacing in sweet corn hybrid named Krasnodarskiy 280 CV growing management and the yield of milky ripeness. We have discovered that straw mulching in combination with complex water-soluble fertilizer named Vermisol used in 5-6 leaves, reduced evaporation and tended to moisture accumulation in soil what increased yield of ears for 0,6-1,7 t/ha. The lowest water-abs...

  16. Effect of different mulching modes on soil moisture evaporation%不同覆盖模式对土壤水分蒸发的影响

    Institute of Scientific and Technical Information of China (English)

    赵文举; 马宏; 郁文; 豆品鑫

    2016-01-01

    To reveal the effect of restraining soil water evaporation with different mulching models, through simulation test,the effect of restraining soil water evaporation was analyzed.Five modes were set up including bare land (CK),sand mulching (S),sand and plastic film mulching (SM),straw and plastic film mulching (JM)and straw and sand mulching (JS).The results show that the soil dai-ly evaporation capacity is different with the different mulching modes of soil surface.In the early evaporation,the soil moisture evaporation capacity is CK >JS >JM>S >SM,then the change trend becomes CK >JS >S >SM>JM.When rainfall occurs,the change of soil moisture evaporation capaci-ty is from CK >JM>SM>JS >S to CK >JS >S >SM>JM.The different mulching models can effec-tively reduce soil water evaporation.Soil water cumulative evaporation capacity of bare land,straw and sand mulching,straw and plastic film mulching,sand mulching,sand and plastic film mulching is re-spectively 1 823.6,712.2,473.3,450.6 and 375.1 g,soil water cumulative evaporation capacity of straw and sand mulching,straw and plastic film mulching,sand mulching,sand and plastic film mul-ching decreases by 60.9%,74.0%,75.3% and 79.4% respectively,compared with CK.In the whole evaporation process,the relationship between soil water cumulative evaporation capacity and time under different mulching models is W=atb .By comprehensive analysis,sand mulching is a more reasonable mulching model in the test area.%为了揭示不同覆盖模式抑制土壤水分蒸发的效果,通过模拟试验,对不同覆盖模式抑制土壤水分蒸发的效果进行了分析.试验设置无覆盖(CK)、覆砂(S)、覆砂+覆膜(SM)、覆秸秆+覆膜(JM)和覆秸秆+覆砂(JS)5种模式.结果表明:土壤表层不同覆盖处理的土壤日蒸发量不同,在蒸发初期,土壤水分蒸发量从大到小依次为 CK,JS,JM,S,SM,之后基本保持 CK,JS,S,SM,JM的变化趋势.当有

  17. The Effects of Farmyard Manure and Mulch on Soil Physical Properties in a Reclaimed Coastal Tidal Flat Salt-Affected Soil

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jian-bing; YANG Jing-song; YAO Rong-jiang; YU Shi-peng; LI Fu-rong; HOU Xiao-jing

    2014-01-01

    Careful soil management is important for the soil quality and productivity improvement of the reclaimed coastal tidal lfat saline land in northern Jiangsu Province, China. Farmyard manure (FYM) and mulch applications, which affect soil characteristics and plant signiifcantly, are regard as an effective pattern of saline land improvement. As a conventional management in the study region, FYM and mulch are used for the amendment of the new reclaimed tidal lfat regularly, but little is known about their effects on soil physical properties functioning. A study was conducted on a typical coastal tidal lfat saline land, which was reclaimed in 2005, to evaluate the effects of FYM, polyethylene iflm mulch (PM), straw mulch (SM), FYM combined with PM (FYM+PM), FYM combined with SM (FYM+SM), on soil hydraulic properties and soil mechanical impedance. CK represented conventional cultivation in study area without FYM and mulch application and served as a control. The experiment, laid out in a randomized complete block design with three replications, was studied in Huanghaiyuan Farm, which specialized in the agricultural utilization for coastal tidal lfat. Result showed that capillary water holding capacity (CHC), saturated water content (SWC), saturated hydraulic conductivity (Ks) and bulk density (BD), cone index (CI) were affected signiifcantly by the FYM and mulch application, especially in the 0-10 cm soil layer. FYM and mulch management increased CHC, SWC and Ks over all soil depth in the order of FYM+SM>FYM+PM>FYM>SM>PM>CK. With the contrary sequence, BD and CI decreased signiifcantly;however, FYM and mulch application affected BD and CI only in the upper soil layers. CHC, SWC and Ks decreased signiifcantly with the increasing of soil depth, BD and CI, and a signiifcant liner equation was found between CHC, SWC, Ks and BD, CI. With the highest CHC (38.15%), SWC (39.55%), Ks (6.00 mm h-1) and the lowest BD (1.26 g cm-3) and CI (2.71 MPa), the combined management of FYM

  18. The Effects of Rape Residue Mulching on Net Global Warming Potential and Greenhouse Gas Intensity from No-Tillage Paddy Fields

    OpenAIRE

    Zhi-Sheng Zhang; Cou-Gui Cao; Li-Jin Guo; Cheng-Fang Li

    2014-01-01

    A field experiment was conducted to provide a complete greenhouse gas (GHG) accounting for global warming potential (GWP), net GWP, and greenhouse gas intensity (GHGI) from no-tillage (NT) paddy fields with different amounts of oilseed rape residue mulch (0, 3000, 4000, and 6000 kg dry matter (DM) ha−1) during a rice-growing season after 3 years of oilseed rape-rice cultivation. Residue mulching treatments showed significantly more organic carbon (C) density for the 0–20 cm soil layer at harv...

  19. EFFECT OF AN IN-SEASON LIVING MULCH ON LEACHING OF INORGANIC NITROGEN IN CAULIFLOWER (BRASSICA OLERACEA L. VAR. BOTRYTIS) CROPPING IN SLOVENIA, GERMANY AND DENMARK

    OpenAIRE

    Kristensen, Hanne Lakkenborg; Campanelli, G.; Bavec, Franc; von Fragstein und Niemsdorff, Peter; Canali, S.; Tittarelli, F.

    2014-01-01

    Vegetables with a high nitrogen demand such as cauliflower may cause intensive leaching of nitrate to the environment in conventional as well as in organic production. In organic cropping systems, the use of an in-season living mulch may decrease the risk of nitrate leaching after harvest when left growing in the field to the end of the leaching season in spring. The aim of this study was to investigate the effect of growing an in-season living mulch including legumes on the risk of leaching ...

  20. Water treatment residual (WTR)-coated wood mulch for alleviation of toxic metals and phosphorus from polluted urban stormwater runoff.

    Science.gov (United States)

    Soleimanifar, Hanieh; Deng, Yang; Wu, Laying; Sarkar, Dibyendu

    2016-07-01

    Aluminum-based water treatment residual (WTR)-coated wood mulches were synthesized and tested for removal of heavy metals and phosphorus (P) in synthetic urban stormwater. WTRs are an industrial waste produced from coagulation in water treatment facilities, primarily composed of amorphous aluminum or iron hydroxides. Batch tests showed that the composite filter media could effectively adsorb 97% lead (Pb), 76% zinc (Zn), 81% copper (Cu) and 97% P from the synthetic stormwater (Pb = 100 μg/L, Zn = 800 μg/L, Cu = 100 μg/L, P = 2.30 mg/L, and pH = 7.0) within 120 min, due to the presence of aluminum hydroxides as an active adsorbent. The adsorption was a 2(nd)-order reaction with respect toward each pollutant. Column tests demonstrated that the WTR-coated mulches considerably alleviated the select pollutants under a continuous-flow condition over the entire filtration period. The effluent Pb, Zn, Cu, and P varied at 0.5-8.9%, 33.4-46.7%, 45.8-55.8%, and 6.4-51.9% of their respective initial concentrations with the increasing bed volume from 0 to 50. Synthetic precipitation leaching procedure (SPLP) and toxicity characteristic leaching procedure (TCLP) tests indicated that leached contaminants were all below the U.S. criteria, suggesting that the release of undesired chemicals under rainfall or landfilling conditions is not a concern during application. This study demonstrates that the WTR-coated mulches are a new, low-cost, and effective filter media for urban stormwater treatment. Equally important, this study provides a sustainable approach to beneficially reuse an industrial waste for environmental pollution control. PMID:27060636

  1. Effect of different mulching materials on maize growth and yield in conservation agriculture systems of sub-humid Zimbabwe

    Directory of Open Access Journals (Sweden)

    W. Mupangwa

    2016-06-01

    Full Text Available The introduction of conservation agriculture (CA for smallholders increased the competition for crop residues between crop and livestock enterprises of the mixed smallholder farming system. Smallholders practicing CA have resorted to using grass and leaf litter in addition to available crop residues. The effect of these different mulching materials on maize (Zea mays L. growth and yield is not well documented in smallholder CA systems of southern Africa. A two-year experiment was run in 2012/13 and 2013/14 seasons to evaluate the effect of maize residues, grass (Hyparrhenia filipendula (L. Stapf. and leaf litter that farmers are currently using and residues from leguminous species, sunhemp (Crotolaria juncea L. and Tephrosia (Tephrosia vogelii ((Hook f. on maize nitrogen (N uptake, growth and yield. Significant differences in soil water content across treatments were only observed during March in 2012/13 season. Maize residues retained more soil water and Tephrosia had the lowest soil water content when seasonal rainfall pattern was erratic. Grass and Tephrosia treatments had the lowest chlorophyll content. Conventional ploughing, maize residues and leaf litter had similar chlorophyll content which was significantly higher than grass and Tephrosia treatments. At a site with higher initial soil fertility conventional ploughing treatment out yielded the other treatments by 727–1265 kg ha−1. With more degraded sandy soil conventional practice had 119–430 kg ha−1 more maize grain than the CA treatments. With adequate fertilization, the mulching materials have a similar effect on maize growth in basins and direct seeding. Further studies on different application rates of mulching materials and mineral N fertilizer, and nutrient release patterns of these residues are critical in order to better understand soil fertility management under smallholder CA systems.

  2. 覆盖方式对温室辣椒结果期生长和水分利用的影响%Effect of mulching mode on growth and water use of greenhouse pepper during fruiting stage

    Institute of Scientific and Technical Information of China (English)

    吴兴; 梁银丽; 郝旺林; 罗安荣; 彭强; 陈晨

    2011-01-01

    在日光温室条件下,通过地膜覆盖、秸秆覆盖、地膜加秸秆覆盖和对照共4个处理的小区试验,研究覆盖方式对温室辣椒结果期生长及水分利用的影响,从中筛选出有利于温室辣椒生产的较佳覆盖模式.结果表明:地膜加秸秆覆盖处理结果初期土壤温度升温幅度大于秸秆覆盖,结果盛期和结果末期土壤温度降温趋势小于地膜覆盖;各覆盖处理都显著促进植株生长,增加结果期辣椒叶片叶绿素相对含量和植株总干重及各部分干重,并显著提高辣椒产量,减少耗水量,其中,地膜加秸秆覆盖表现尤为突出;地膜加秸秆覆盖、地膜覆盖和秸秆覆盖处理的水分利用效率分别为对照的2.17倍、2.09倍、1.67倍.总之,地膜加秸秆覆盖是利于日光温室辣椒生产、提高水分利用效率的较佳覆盖方式.%The effects of different mulching treatments (e.g., plastic film mulching, wheat straw mulching, combined plastic film and wheat straw mulching and no mulching) on the growth and water use of greenhouse pepper during fruiting stage were studied in order to establish an optimum mulching mode for greenhouse pepper production. The results showed that soil temperature increasing extent under combined plastic film and wheat straw mulching treatment was higher than that under straw mulching treatment at the early fruiting stage. At the middle and late fruiting stage, soil temperature decreasing extent was lower under combined plastic film and wheat straw mulching treatment than that under plastic film mulching treatment. Mulching significantly promoted greenhouse pepper growth, and increased leaf chlorophyll content, gross and plant-part dry weight, and fruit yield. Mulching also reduced water consumption. Combined plastic film and wheat straw mulching had the strongest effect on growth and water use characteristics of greenhouse pepper. Greenhouse pepper water use efficiency under plastic film mulching, wheat

  3. Forest litter as the mulch improving growth and ectomycorrhizal diversity of bare-root Scots pine (Pinus sylvestris) seedlings

    OpenAIRE

    Aučina A; Rudawska M; Leski T; Skridaila A; Pašakinskiene I; Riepšas E

    2015-01-01

    In this paper, we report the influence of pine, oak and spruce forest litter on the growth and ectomycorrhizal (ECM) formation of Scots pine seedlings after the first growing season in a bare-root forest nursery. The mixture of collected forest litters and humus were used to obtain a 20-cm mulching layer on the prepared seedbeds. The concentrations of all nutrients and the C/N ratio of growth media were significantly higher in forest litter treatments than in negative control represented by m...

  4. Biodegradable compounds: Rheological, mechanical and thermal properties

    Science.gov (United States)

    Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

    2015-12-01

    Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

  5. Bio-Degradable Plastics Impact On Environment

    Directory of Open Access Journals (Sweden)

    T.SUBRAMANI

    2014-06-01

    Full Text Available The potential of biodegradable polymers and more particularly that of polymers obtained from renewable resources such as the polysaccharides (e.g., starch have long been recognized. However, these biodegradable polymers have been largely used in some applications (e.g., food industry and have not found extensive applications in the packaging industries to replace conventional plastic materials, although they could be an interesting way to overcome the limitation of the petrochemical resources in the future. The fossil fuel and gas could be partially replaced by greener agricultural sources, which should participate in the reduction of CO2 emissions. Bio-based and biodegradable plastics can form the basis for environmentally preferable, sustainable alternative to current materials based exclusively on petroleum feed stocks. These bio-based materials offer value in the sustainability/life-cycle equation by being a part of the biological carbon cycle, especially as it relates to carbon-based polymeric materials such as plastics, water soluble polymers and other carbon based products like lubricants, biodiesel, and detergents. Identification and quantification of bio based content uses radioactive C-14 signature. Biopolymers are generally capable of being utilized by living matter (biodegraded, and so can be disposed in safe and ecologically sound ways through disposal processes (waste management like composting, soil application, and biological wastewater treatment. Single use, short-life, disposable products can be engineered to be bio-based and biodegradable.

  6. Weed control in tomato (lycopersicon esculentum mill.) through mulching and herbicides

    International Nuclear Information System (INIS)

    Experiments were conducted at the Agricultural Research Farm of the University of Agriculture, Peshawar during 2012 and 2013 to determine the impact of row spacing and weed management strategies on tomato (Lycopersicon esculantum Mill.). Variety 'Roma' was planted on a plot size of 4.8m x 3m using a randomized complete block (RCB) design in split plot arrangements, having four replications. The experiment comprised of row spacing in main plots and ten treatments in the subplots that included five mulches viz., white polyethylene, black polyethylene, wheat straw, newspaper and saw dust; three herbicide treatments i.e. fenoxaprop-p-ethyl, pendimethalin, s-metolachlor along with a hand weeding treatment and a weedy check. The data were recorded on weed density m-2 at 20 days after treatments, plant height, fruit yield (kg ha-1). All the studied parameters were significantly affected by the row spacing (factor A) and weed management treatments (factor B); however, the interaction effects were non-significant. An increase in weed density was observed with increase in row spacing, having weed density of 3.39, 4.19 and 4.53 weeds m-2 for 40, 60 and 80 row spacing, respectively. The overall weed density m-2 ranged between 3.24 to 4.30 m-2. A maximum plant height of 62.44cm was recorded in weedy check and minimum 53.31cm plant height was observed in hand weeding treatments. As regards the fruit yield, a highest yield of 2.51 t ha-1 was recorded at row spacing of 60 cm (factor A) and the application of poly ethylene black plastic resulted in significantly highest fruit yield (4.04 t ha-1) among factor B treatments. (author)

  7. Effect of plastic mulching on mycotoxin occurrence and mycobiome abundance in soil samples from asparagus crops.

    Science.gov (United States)

    Muñoz, K; Schmidt-Heydt, M; Stoll, D; Diehl, D; Ziegler, J; Geisen, R; Schaumann, G E

    2015-11-01

    Plastic mulching (PM) is widely used in modern agriculture because of its advantageous effects on soil temperature and water conservation, factors which strongly influence the microbiology of the soil. The aim of this study was to assess the effect of PM on mycotoxin occurrence in relation with mycobiome abundance/diversity and soil physicochemical properties. Soil samples were collected from green (GA) and white asparagus (WA) crops, the last under PM. Both crops were cultivated in a ridge-furrow-ridge system without irrigation. Samples were analyzed for mycotoxin occurrence via liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Total colony-forming unit was indicative of mycobiome abundance, and analysis of mycobiome diversity was performed by internal transcribed spacer (ITS) sequencing. PM avoided the drop of soil temperature in winter and allowed higher soil temperature in early spring compared to non-covered soil. Moreover, the use of PM provided controlled conditions for water content in soil. This was enough to generate a dissimilar mycotoxin occurrence and mycobiome diversity/abundance in covered and non-covered soil. Mycotoxin soil contamination was confirmed for deoxynivalenol (DON), range LOD to 32.1 ng/g (LOD = 1.1 ng/g). The DON values were higher under PM (average 16.9 ± 10.1 ng/g) than in non-covered soil (9.1 ± 7.9 ng/g); however, this difference was not statically significant (p = 0.09). Mycobiome analysis showed a fungal compartment up to fivefold higher in soil under PM compared to GA. The diversity of the mycobiome varied between crops and also along the soil column, with an important dominance of Fusarium species at the root zone in covered soils. PMID:26412448

  8. Biodegradable Photonic Melanoidin for Theranostic Applications.

    Science.gov (United States)

    Lee, Min-Young; Lee, Changho; Jung, Ho Sang; Jeon, Mansik; Kim, Ki Su; Yun, Seok Hyun; Kim, Chulhong; Hahn, Sei Kwang

    2016-01-26

    Light-absorbing nanoparticles for localized heat generation in tissues have various biomedical applications in diagnostic imaging, surgery, and therapies. Although numerous plasmonic and carbon-based nanoparticles with strong optical absorption have been developed, their clearance, potential cytotoxicity, and long-term safety issues remain unresolved. Here, we show that "generally regarded as safe (GRAS)" melanoidins prepared from glucose and amino acid offer a high light-to-heat conversion efficiency, biocompatibility, biodegradability, nonmutagenicity, and efficient renal clearance, as well as a low cost for synthesis. We exhibit a wide range of biomedical photonic applications of melanoidins, including in vivo photoacoustic mapping of sentinel lymph nodes, photoacoustic tracking of gastrointestinal tracts, photothermal cancer therapy, and photothermal lipolysis. The biodegradation rate and renal clearance of melanoidins are controllable by design. Our results confirm the feasibility of biodegradable melanoidins for various photonic applications to theranostic nanomedicines. PMID:26623481

  9. Biodegradable nanoparticles for gene therapy technology

    International Nuclear Information System (INIS)

    Rapid propagations in materials technology together with biology have initiated great hopes in the possibility of treating many diseases by gene therapy technology. Viral and non-viral gene carriers are currently applied for gene delivery. Non-viral technology is safe and effective for the delivery of genetic materials to cells and tissues. Non-viral systems are based on plasmid expression containing a gene encoding a therapeutic protein and synthetic biodegradable nanoparticles as a safe carrier of gene. Biodegradable nanoparticles have shown great interest in drug and gene delivery systems as they are easy to be synthesized and have no side effect in cells and tissues. This review provides a critical view of applications of biodegradable nanoparticles on gene therapy technology to enhance the localization of in vitro and in vivo and improve the function of administered genes

  10. Biodegradable Polymers and Stem Cells for Bioprinting

    Directory of Open Access Journals (Sweden)

    Meijuan Lei

    2016-04-01

    Full Text Available It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism.

  11. Biodegradable Polymers and Stem Cells for Bioprinting.

    Science.gov (United States)

    Lei, Meijuan; Wang, Xiaohong

    2016-01-01

    It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism. PMID:27136526

  12. Petroleum biodegradation and oil spill bioremediation

    International Nuclear Information System (INIS)

    Hydrocarbon-utilizing microorganisms are ubiquitously distributed in the marine environment following oil spills. These microorganisms naturally biodegrade numerous contaminating petroleum hydrocarbons, thereby cleansing the oceans of oil pullutants. Bioremediation, which is accomplished by adding exogenous microbial populations or stimulating indigenous ones, attempts to raise the rates of degradation found naturally to significantly higher rates. Seeding with oil degraders has not been demonstrated to be effective, but addition of nitrogenous fertilizers has been shown to increase rates of petroleum biodegradation. In the case of the Exxon Valdez spill, the largest and most thoroughly studied application of bioremediation, the application of fertilizer (slow release or oleophilic) increased rates of biodegradation 3-5 times. Because of the patchiness of oil, an internally conserved compound, hopane, was critical for demonstrating the efficacy of bioremediation. Multiple regression models showed that the effectiveness of bioremediation depended upon the amount of nitrogen delivered, the concentration of oil, and time. (author)

  13. Biodegradable nanoparticles for gene therapy technology

    Energy Technology Data Exchange (ETDEWEB)

    Hosseinkhani, Hossein, E-mail: hosseinkhani@mail.ntust.edu.tw; He, Wen-Jie [National Taiwan University of Science and Technology (Taiwan Tech), Graduate Institute of Biomedical Engineering (China); Chiang, Chiao-Hsi [School of Pharmacy, National Defense Medical Center (China); Hong, Po-Da [National Taiwan University of Science and Technology (Taiwan Tech), Graduate Institute of Biomedical Engineering (China); Yu, Dah-Shyong [Nanomedicine Research Center, National Defense Medical Center (China); Domb, Abraham J. [The Hebrew University of Jerusalem, Institute of Drug Research, School of Pharmacy, Faculty of Medicine, Center for Nanoscience and Nanotechnology and The Alex Grass Center for Drug Design and Synthesis (Israel); Ou, Keng-Liang [College of Oral Medicine, Taipei Medical University, Research Center for Biomedical Devices and Prototyping Production (China)

    2013-07-15

    Rapid propagations in materials technology together with biology have initiated great hopes in the possibility of treating many diseases by gene therapy technology. Viral and non-viral gene carriers are currently applied for gene delivery. Non-viral technology is safe and effective for the delivery of genetic materials to cells and tissues. Non-viral systems are based on plasmid expression containing a gene encoding a therapeutic protein and synthetic biodegradable nanoparticles as a safe carrier of gene. Biodegradable nanoparticles have shown great interest in drug and gene delivery systems as they are easy to be synthesized and have no side effect in cells and tissues. This review provides a critical view of applications of biodegradable nanoparticles on gene therapy technology to enhance the localization of in vitro and in vivo and improve the function of administered genes.

  14. Biodegradability Evaluation of Polymers by ISO 14855-2

    OpenAIRE

    Masao Kunioka; Fumi Ninomiya; Masahiro Funabashi

    2009-01-01

    Biodegradabilities of polymers and their composites in a controlled compost were described. Polycaprolactone (PCL) and poly(lactic acid) (PLA) were employed as biodegradable polymers. Biodegradabilities of PCL and PLA samples in a controlled compost were measured using a Microbial Oxidative Degradation Analyzer (MODA) according to ISO 14855-2. Sample preparation method for biodegradation test according to ISO/DIS 10210 was also described. Effects of sizes and shapes of samples on biodegradabi...

  15. Synchronization of flexible sheets

    CERN Document Server

    Elfring, Gwynn J; 10.1017/S0022112011000814

    2011-01-01

    When swimming in close proximity, some microorganisms such as spermatozoa synchronize their flagella. Previous work on swimming sheets showed that such synchronization requires a geometrical asymmetry in the flagellar waveforms. Here we inquire about a physical mechanism responsible for such symmetry-breaking in nature. Using a two-dimensional model, we demonstrate that flexible sheets with symmetric internal forcing, deform when interacting with each other via a thin fluid layer in such a way as to systematically break the overall waveform symmetry, thereby always evolving to an in-phase conformation where energy dissipation is minimized. This dynamics is shown to be mathematically equivalent to that obtained for prescribed waveforms in viscoelastic fluids, emphasizing the crucial role of elasticity in symmetry-breaking and synchronization.

  16. Biodegradable polyesters based on succinic acid

    Directory of Open Access Journals (Sweden)

    Nikolić Marija S.

    2003-01-01

    Full Text Available Two series of aliphatic polyesters based on succinic acid were synthesized by copolymerization with adipic acid for the first series of saturated polyesters, and with fumaric acid for the second series. Polyesters were prepared starting from the corresponding dimethyl esters and 1,4-butanediol by melt transesterification in the presence of a highly effective catalyst tetra-n-butyl-titanate, Ti(0Bu4. The molecular structure and composition of the copolyesters was determined by 1H NMR spectroscopy. The effect of copolymer composition on the physical and thermal properties of these random polyesters were investigated using differential scanning calorimetry. The degree of crystallinity was determined by DSC and wide angle X-ray. The degrees of crystallinity of the saturated and unsaturated copolyesters were generally reduced with respect to poly(butylene succinate, PBS. The melting temperatures of the saturated polyesters were lower, while the melting temperatures of the unsaturated copolyesters were higher than the melting temperature of PBS. The biodegradability of the polyesters was investigated by enzymatic degradation tests. The enzymatic degradation tests were performed in a buffer solution with Candida cylindracea lipase and for the unsaturated polyesters with Rhizopus arrhizus lipase. The extent of biodegradation was quantified as the weight loss of polyester films. Also the surface of the polyester films after degradation was observed using optical microscopy. It could be concluded that the biodegradability depended strongly on the degree of crystallinity, but also on the flexibility of the chain backbone. The highest biodegradation was observed for copolyesters containing 50 mol.% of adipic acid units, and in the series of unsaturated polyesters for copolyesters containing 5 and 10 mol.% of fumarate units. Although the degree of crystallinity of the unsaturated polyesters decreased slightly with increasing unsaturation, the biodegradation

  17. Histological evaluation of different biodegradable and non-biodegradable membranes implanted subcutaneously in rats

    DEFF Research Database (Denmark)

    Zhao, S; Pinholt, E M; Madsen, J E; Donath, K

    2000-01-01

    Different types of biodegradable membranes have become available for guided tissue regeneration. The purpose of this study was to evaluate histologically three different biodegradable membranes (Bio-Gide, Resolut and Vicryl) and one non-biodegradable membrane (expanded polytetrafluoroethylene/e-PTFE...... that e-PTFE was well tolerated and encapsulated by a fibrous connective tissue capsule. There was capsule formation around Resolut and Vicryl and around Bio-Gide in the early phase there was a wide inflammatory zone already. e-PTFE and Vicryl were stable materials while Resolut and Bio-Gide fragmented...

  18. Information sheets on energy

    International Nuclear Information System (INIS)

    These sheets, presented by the Cea, bring some information, in the energy domain, on the following topics: the world energy demand and the energy policy in France and in Europe, the part of the nuclear power in the energy of the future, the greenhouse gases emissions and the fight against the greenhouse effect, the carbon dioxide storage cost and the hydrogen economy. (A.L.B.)

  19. Biomolecular Science (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-04-01

    A brief fact sheet about NREL Photobiology and Biomolecular Science. The research goal of NREL's Biomolecular Science is to enable cost-competitive advanced lignocellulosic biofuels production by understanding the science critical for overcoming biomass recalcitrance and developing new product and product intermediate pathways. NREL's Photobiology focuses on understanding the capture of solar energy in photosynthetic systems and its use in converting carbon dioxide and water directly into hydrogen and advanced biofuels.

  20. Biodegradable containers from green waste materials

    Science.gov (United States)

    Sartore, Luciana; Schettini, Evelia; Pandini, Stefano; Bignotti, Fabio; Vox, Giuliano; D'Amore, Alberto

    2016-05-01

    Novel biodegradable polymeric materials based on protein hydrolysate (PH), derived from waste products of the leather industry, and poly(ethylene glycol) diglycidyl ether (PEG) or epoxidized soybean oil (ESO) were obtained and their physico-chemical properties and mechanical behaviour were evaluated. Different processing conditions and the introduction of fillers of natural origin, as saw dust and wood flour, were used to tailor the mechanical properties and the environmental durability of the product. The biodegradable products, which are almost completely manufactured from renewable-based raw materials, look promising for several applications, particularly in agriculture for the additional fertilizing action of PH or in packaging.

  1. Biodegradable multifunctional oil production chemicals: Thermal polyaspartates

    International Nuclear Information System (INIS)

    The paper deals with biodegradable oil production chemicals. Control of both mineral scale and corrosion with a single, environmentally acceptable material is an ambitious goal. Polyaspartate polymers represent a significant milestone in the attainment of this goal. Thermal polyaspartates (TPA) are polycarboxylate polymers derived via thermal condensation of the naturally occurring amino acid aspartic acid. These protein-like polymers are highly biodegradable and non-toxic, and are produced by an environmentally benign manufacturing process. TPAs exhibit excellent mineral scale inhibition activity and CO2 corrosion control. Laboratory data on scale inhibition and corrosion control in the North Sea oil field production applications is presented. 8 refs., 2 figs., 6 tabs

  2. Musical Sheet Segmentation

    Directory of Open Access Journals (Sweden)

    Vinaya V

    2014-05-01

    Full Text Available Music has had an important role in human life from time immemorial. Music has been shared in two ways aurally and as written documents known as musical notes or musical scores. Many ancient cultures have used musical symbols to represent melodies and lyrics but none of them is as comprehensive as a written language or document. Thus the knowledge of ancient music is limited to a few fragments which are mostly unpublished. Hence to preserve such music we need to introduce a computerized system to digitalize and to decode the musical symbol images and reconstruct it as new score which will be in machine readable format. Here the machine readable format is MIDI. Prior to converting the musical symbols into MIDI format, musical sheets need to be segmented for isolating the musical symbols. Since synthetically generated musical sheets are used here, the segmentation process can be carried out using recursive graph cut method. Here we discuss the initial few steps such as staff line removal, text removal and segmentation of musical sheet.

  3. Synthetic biodegradable functional polymers for tissue engineering: a brief review

    OpenAIRE

    BaoLin, GUO; Ma, Peter X.

    2014-01-01

    Scaffolds play a crucial role in tissue engineering. Biodegradable polymers with great processing flexibility are the predominant scaffolding materials. Synthetic biodegradable polymers with well-defined structure and without immunological concerns associated with naturally derived polymers are widely used in tissue engineering. The synthetic biodegradable polymers that are widely used in tissue engineering, including polyesters, polyanhydrides, polyphosphazenes, polyurethane, and poly (glyce...

  4. Soluble Eggshell Mebrane Protein:Antibacterial Property and Biodegradability

    Institute of Scientific and Technical Information of China (English)

    YI Feng; YU Jian; LI Qiang; GUO Zhaoxia

    2007-01-01

    The antibacterial property and biodegradability of soluble eggshell membrane protein (SEP)are reported. Unlike the natural eggshell membrane (ESM), SEP does not possess antibacterial property against E.coli. The biodegradation tests with trypsin show that both ESM and SEP are biodegradable.

  5. Effects of Bahia Grass Cover and Mulch on Runoff and Sediment Yield of Sloping Red Soil in Southern China

    Institute of Scientific and Technical Information of China (English)

    LI Xin-Hu; ZHANG Zhan-Yu; YANG Jie; ZHANG Guo-Hua; WANG Bin

    2011-01-01

    Rainfall, runoff (surface runoff, interflow and groundwater runoff) and soil loss from 5 m × 15 m plots were recorded for 5 years (2001-2005) in an experiment with three treatments (cover, mulch and bare ground) on sloping red soil in southern China. Surface runoff and erosion from the Bahia grass (Paspalum notatum Flugge) cover plot (A) and mulch plot (B) during the 5 years were low,despite the occurrence of potentially erosive rains. In contrast, the bare plot (C) had both the highest surface runoff coefficient and the highest sediment yield. There were significant differences in interflow and surface runoff and no significant difference in groundwater runoff among plots. The runoff coefficients and duration of interflow and groundwater runoff were in the order plot B > plot A > plot C. Effects of Bahia grass cover were excellent, indicating that the use of Bahia grass cover can be a simple and feasible practice for soil and water conservation on sloping red soil in the region.

  6. Fungal bio-degradation of 14C-parathion

    International Nuclear Information System (INIS)

    14'C-parathion (670 Bq) was applied to mineral salt medium (MSM) to examine and evaluate its biodegradation by some fungi. The studied isolates were Alternaria alternate, Fusarium oxysporim and trichoderma viride. The inoculated media were incubated at 30 oC for periods of 2, 4, 6 and 8 days. Ta each interval, mycelia were separated from nutrient solution and extracted for its radioactivity. However, non extractable compounds were liberated by combustion. Quantitative and qualitative analysis were carried out for the radioactive compound in mycelia l extracts and residues as well as the fungal culture filtrate. Balance sheet for total recovered radioactive compounds was concluded 14'C-parathion metabolism was expressed as original compound, polar metabolite, non polar metabolites and non extractable residues and then degradation rate was calculated. araesults indicated that there was continuous penetration for the radioactivity into mycelia tissues and the maximum, accumulation was recorded by Fusarium Oxysporium. The fungi under investigation showed considerable variations regarding their capacity to degrade the radioactive pesticide. Trichoderma viride exhibited the maximum capability to catabolism the the 14C-parathion as it exerted the maximum degradation rate. Fusarium and Alternate alter nata showed less degradation rates for the 14C- pesticide under investigation. (Author)

  7. Comparative study on the biodegradation and biocompatibility of silicate bioceramic coatings on biodegradable magnesium alloy as biodegradable biomaterial

    Science.gov (United States)

    Razavi, M.; Fathi, M. H.; Savabi, O.; Razavi, S. M.; Hashemibeni, B.; Yazdimamaghani, M.; Vashaee, D.; Tayebi, L.

    2014-03-01

    Many clinical cases as well as in vivo and in vitro assessments have demonstrated that magnesium alloys possess good biocompatibility. Unfortunately, magnesium and its alloys degrade too quickly in physiological media. In order to improve the biodegradation resistance and biocompatibility of a biodegradable magnesium alloy, we have prepared three types of coating include diopside (CaMgSi2O6), akermanite (Ca2MgSi2O6) and bredigite (Ca7MgSi4O16) coating on AZ91 magnesium alloy through a micro-arc oxidation (MAO) and electrophoretic deposition (EPD) method. In this research, the biodegradation and biocompatibility behavior of samples were evaluated in vitro and in vivo. The in vitro analysis was performed by cytocompatibility and MTT-assay and the in vivo test was conducted on the implantation of samples in the greater trochanter of adult rabbits. The results showed that diopside coating has the best bone regeneration and bredigite has the best biodegradation resistance compared to others.

  8. Effects of Plastic Film Mulching of Millet on Soil Moisture and Temperature in Semi-Arid Areas in South Ningxia of China

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The effects of film mulching of millet on soil water content were studied in semi-arid areas in the Loess Plateau of South Ningxia, China. Different mulching methods including water micro-collecting farming (WF), water micro-collecting farming in winter fallow (WW), hole seeding on film (HF), hole seeding on film in winter fallow (HW) were compared to determine the effects of mulching methods on soil water collecting and conservation during millet growth periods of 2003-2004, as well as the variation tendency of water content after rainfall, output of millet and water use efficiency (WUE). The experimental results in the two successive years indicated that water micro-collecting farming had a better function of collecting water after rainfall, and side infiltrated water was stored under the ridges and the top layer 0-40 cm soil water changes were great. WF had obvious role in water collection and preservation of soil moisture. It effectively improved the water supply capacity by about 19.05% in the end of growth seasons. The storage of HW and WW increased by 24.9 and 7.1 mm compared with CK, and output of yield were obviously increased. Film mulching increased the yield of millet and enhanced water use efficiency (WUE). During different growth periods, WF exhibited better water storage function with lower water consumption, and demonstrated optimal social and ecological benefits.

  9. [Effects of soil wetting pattern on the soil water-thermal environment and cotton root water consumption under mulched drip irrigation].

    Science.gov (United States)

    Li, Dong-wei; Li, Ming-si; Liu, Dong; Lyu, Mou-chao; Jia, Yan-hui

    2015-08-01

    Abstract: To explore the effects of soil wetting pattern on soil water-thermal environment and water consumption of cotton root under mulched drip irrigation, a field experiment with three drip intensities (1.69, 3.46 and 6.33 L · h(-1)), was carried out in Shihezi, Xinjiang Autonomous Region. The soil matric potential, soil temperature, cotton root distribution and water consumption were measured during the growing period of cotton. The results showed that the main factor influencing the soil temperature of cotton under plastic mulch was sunlight. There was no significant difference in the soil temperature and root water uptake under different treatments. The distribution of soil matrix suction in cotton root zone under plastic mulch was more homogeneous under ' wide and shallow' soil wetting pattern (W633). Under the 'wide and shallow' soil wetting pattern, the average difference of cotton root water consumption between inner row and outer row was 0.67 mm · d(-1), which was favorable to the cotton growing trimly at both inner and outer rows; for the 'narrow and deep' soil wetting pattern (W169), the same index was 0.88 mm · d(-1), which was unfavorable to cotton growing uniformly at both inner and outer rows. So, we should select the broad-shallow type soil wetting pattern in the design of drip irrigation under mulch. PMID:26685608

  10. The effects of film-mulching on the translocation and distribution in 14C-assimilates after anthesis in winter wheat (Triticum aestivum L.) on dryland

    International Nuclear Information System (INIS)

    The effects of film-mulching on transportation and distribution of 14C-assimilates after anthesis of winter wheat on dryland were investigated using 14C-radiolabelling technique. The results showed that about 78% of 14C-assimilates was stored in the stem and sheath after 24 hours, 11% was transported into the kernels, and about 11% remained in leaves. At maturity, 14C-assimilates were almost entirely transported from the leaves, about 28% 14C was found in the stem and sheath, and about 70% was in the kernels. The 14C-assimilates in wheat with film-mulching were transported slower than that in the control. The results also suggested that under the film-mulching conditions, the leaves had higher chlorophyll contents, lower MDA contents, slower speed in the senescence and a stronger assimilability, while the wheat had much more dry matter and higher kernel yield. It was concluded that the reasons of the yield increase under the film-mulching were mainly on the faster growth during the early stage, the slower senescence in the later stage, and a stronger assimilation, leading to a great increase of the dry matter. However, this may not enhance the assimilate translocation and distribution to the kernels. (authors)

  11. Distribution And Efficacy Of Drip-Applied Metam-Sodium Against The Survival Of Rhizoctonia Solani And Yellow Nutsedge In Plastic-Mulched Sandy Soil Beds

    Science.gov (United States)

    The effects of metam-sodium application rate on soil residence time, spatial and temporal distributions of methyl isothiocyanate and pest control efficacy were studied in a Georgia sandy soil. Metam-sodium 420 gL-1 SL was drip applied at rates of 147 and 295Lha-1 in plastic-mulched raised beds. Meth...

  12. THE INFLUENCE OF VERMISOL COMPLEX WATER-SOLUBLE FERTILIZER AND STRAW MULCHING OF ROW-SPACINGS FOR SOIL MOISTURE IN SWEET CORN GROWING MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Sidorenko S. E.

    2015-02-01

    Full Text Available The article reveals issues concerning the experiments on application of complex water-soluble fertilizer and straw mulching of row-spacing in sweet corn hybrid named Krasnodarskiy 280 CV growing management and the yield of milky ripeness. We have discovered that straw mulching in combination with complex water-soluble fertilizer named Vermisol used in 5-6 leaves, reduced evaporation and tended to moisture accumulation in soil what increased yield of ears for 0,6-1,7 t/ha. The lowest water-absorbing capacity in root-inhabited layer of soil (0-0,6 m were 28,5 % from dry weight of soil in years of experiment. Registration of sum of precipitations in critical for corn period (in third decade of June and first decade of July was in tolerable level. The best conditions of precipitation were in 2013, when in June and July the sum was 143 mm, and humidity of the air was in optimum level – 70 %. The temperature of the soil in 0-0,1 m layer in the day of mulching was the same as in the layer 0-0,05 m, tin increase for 5 0C in variants without mulching. The lower amplitude of temperature of the soil in vegetation period since the phase of 10-11 leaves had good influence for yield of milk maturity ears

  13. Invloed van ras, mulch en bemesting op de productie en het saldo van sopropo en kouseband : verslag van een proef te Saramacca, Suriname

    NARCIS (Netherlands)

    Putter, de H.; Wongsonadi, H.

    2010-01-01

    In 2010 werd een proef met sopropo (Momordica charanti) en een proef met kouseband (Vigna unguiculata sesquipedalis) uitgevoerd bij een teler in Suriname in de regio Saramacca. Doel was om het effect van variëteit, toepassing van mulch en bemestingstrategie op de productie en op het gewassaldo vast

  14. Biodegradable polymers in clinical use and clinical development

    CERN Document Server

    Domb, Abraham J

    2011-01-01

    The definitive guide to biodegradable polymer science-where we are and what's to come The most comprehensive review of biodegradable polymers already utilized or under development for clinical use, Biodegradable Polymers in Clinical Use and Clinical Development looks at the state of biodegradable polymers now and over the next five years. Implantable molecules that break down within the body over a predetermined period of time, biodegradable polymers have been employed as drug carriers, orthopedic fixation devices, and absorbable sutures. Yet while hundreds of such polymers have been deve

  15. Biodegradation of chlorobenzoic acids by ligninolytic fungi

    Czech Academy of Sciences Publication Activity Database

    Muzikář, Milan; Křesinová, Zdena; Svobodová, Kateřina; Filipová, Alena; Čvančarová, Monika; Cajthamlová, Kamila; Cajthaml, Tomáš

    2011-01-01

    Roč. 196, - (2011), s. 386-394. ISSN 0304-3894 R&D Projects: GA MŠk 2B06156; GA ČR GA525/09/1058 Institutional research plan: CEZ:AV0Z50200510 Keywords : Chlorobenzoic acid * Polychlorinated biphenyls * Biodegradation Subject RIV: EE - Microbiology, Virology Impact factor: 4.173, year: 2011

  16. Fabrication of Environmentally Biodegradable Lignin Nanoparticles

    NARCIS (Netherlands)

    Frangville, C.; Rutkevicius, M.; Richter, A.P.; Velev, O.D.; Stoyanov, S.D.; Paunov, V.N.

    2012-01-01

    We developed a method for the fabrication of novel biodegradable nanoparticles (NPs) from lignin which are apparently non-toxic for microalgae and yeast. We compare two alternative methods for the synthesis of lignin NPs which result in particles of very different stability upon change of pH. The fi

  17. Natural Biodegradation of Phenolic Compounds in Groundwater

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A combination of field data and theoretical approaches is used to assess the natural attenuation and status of a complex plume of phenolic compounds (phenol, cresols, xylenols) in a deep, consolidated, UK Permo-Triassic sandstone aquifer. Biodegradation of the phenolic compounds at concentrations up to 12500mg·L-1 is occurring under aerobic, NO-3-reducing, Mn/Fe-reducing, SO2-4-reducing and methanogenic conditions in the aquifer, with the accumulation of inorganic and organic metabolites in the plume. An electron and carbon balance for the plume suggests that only 6% of the source term has been degraded in 50 years. The residual contaminant mass in the plume significantly exceeds estimates of electron acceptor inputs, indicating that the plume will grow. Two detailed vertical profiles through the plume show that contaminant distributions are controlled more by source history than by biodegradation processes. Microbiological and mass balance studies show that biodegradation is greatest at the plume fringe where contaminant concentrations are diluted by transverse mixing. Active bacterial populations exist throughout the plume but biodegradation is inhibited in the plume core by high contaminant concentrations. Stable isotope studies show that SO2-4-reduction is particularly sensitive to contaminant concentration. The aquifer is not oxidant-deficient but natural attenuation of the phenolic compounds in this system is limited by toxicity from the pollutant load and the bioavailability of electron acceptors. Natural attenuation of these contaminants will increase only after increased dilution of the plume.

  18. Biodegradable polymersomes for targeted ultrasound imaging

    NARCIS (Netherlands)

    Zhou, W.; Meng, F.; Engbers, G.H.M.; Feijen, J.

    2006-01-01

    Biodegradable polymersomes with a sub-micron size were prepared by using poly(ethylene glycol)–polylactide (PEG–PDLLA) block-copolymers in aqueous media. Air-encapsulated polymersomes could be obtained by a lyophilization/rehydration procedure. Preliminary results showed that these polymersomes were

  19. Transport of nonlinearly biodegradable contaminants in aquifers

    NARCIS (Netherlands)

    Keijzer, H.

    2001-01-01

    This thesis deals with the transport behavior of nonlinearly biodegradable contaminants in aquifers. Such transport occurs during in situ bioremediation which is based on the injection of an electron acceptor or electron donor. The main interests in this thesis are the mutual influences of underlyin

  20. Polyvinyl alcohol biodegradation under denitrifying conditions

    Czech Academy of Sciences Publication Activity Database

    Marušincová, H.; Husárová, L.; Růžička, J.; Ingr, M.; Navrátil, Václav; Buňková, L.; Koutný, M.

    2013-01-01

    Roč. 84, October (2013), s. 21-28. ISSN 0964-8305 Grant ostatní: GA ČR(CZ) GAP108/10/0200 Institutional support: RVO:61388963 Keywords : polyvinyl alcohol * biodegradation * denitrification * waste-water treatment * anaerobic * Steroidobacter Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.235, year: 2013

  1. Biodegradability of leathers through anaerobic pathway.

    Science.gov (United States)

    Dhayalan, K; Fathima, N Nishad; Gnanamani, A; Rao, J Raghava; Nair, B Unni; Ramasami, T

    2007-01-01

    Leather processing generates huge amounts of both solid and liquid wastes. The management of solid wastes, especially tanned leather waste, is a challenging problem faced by tanners. Hence, studies on biodegradability of leather become imperative. In this present work, biodegradability of untanned, chrome tanned and vegetable tanned leather under anaerobic conditions has been addressed. Two different sources of anaerobes have been used for this purpose. The effect of detanning as a pretreatment method before subjecting the leather to biodegradation has also been studied. It has been found that vegetable tanned leather leads to more gas production than chrome tanned leather. Mixed anaerobic isolates when employed as an inoculum are able to degrade the soluble organics of vegetable tanned material and thus exhibit an increased level of gas production during the initial days, compared to the results of the treatments that received the anaerobic sludge. With chrome tanned materials, there was not much change in the volume of the gas produced from the two different sources. It has been found that detanning tends to improve the biodegradability of both types of leathers. PMID:16740383

  2. Biodegradable synthetic polymers for tissue engineering

    Directory of Open Access Journals (Sweden)

    Gunatillake P. A.

    2003-05-01

    Full Text Available This paper reviews biodegradable synthetic polymers focusing on their potential in tissue engineering applications. The major classes of polymers are briefly discussed with regard to synthesis, properties and biodegradability, and known degradation modes and products are indicated based on studies reported in the literature. A vast majority of biodegradable polymers studied belongs to the polyester family, which includes polyglycolides and polylactides. Some disadvantages of these polymers in tissue engineering applications are their poor biocompatibility, release of acidic degradation products, poor processability and loss of mechanical properties very early during degradation. Other degradable polymers such as polyorthoesters, polyanhydrides, polyphosphazenes, and polyurethanes are also discussed and their advantages and disadvantages summarised. With advancements in tissue engineering it has become necessary to develop polymers that meet more demanding requirements. Recent work has focused on developing injectable polymer compositions based on poly (propylene fumarate and poly (anhydrides to meet these requirements in orthopaedic tissue engineering. Polyurethanes have received recent attention for development of degradable polymers because of their great potential in tailoring polymer structure to achieve mechanical properties and biodegradability to suit a variety of applications.

  3. Biodegradable Polymeric Microcapsules: Preparation and Properties

    NARCIS (Netherlands)

    Sawalha, H.I.M.; Schroën, C.G.P.H.; Boom, R.M.

    2011-01-01

    Biodegradable polymeric microcapsules can be produced through different methods of which emulsion solvent-evaporation/extraction is frequently used. In this technique, the polymer (often polylactide) is dissolved in a good solvent and is emulsified together with a poor solvent into a nonsolvent phas

  4. ENGINEERING BULLETIN: IN SITU BIODEGRADATION TREATMENT

    Science.gov (United States)

    In situ biodegradation may be used to treat low-to-intermediate concentrations of organic contaminants in place without disturbing or displacing the contaminated media. Although this technology has been used to degrade a limited number of inorganics, specifically cyanide and nitr...

  5. Biodegradable PEG-based drug carriers

    Czech Academy of Sciences Publication Activity Database

    Pechar, Michal; Braunová, Alena; Ulbrich, Karel; Jelínková, Markéta; Říhová, Blanka; Seymour, L. W.

    Glasgow : University of Strathclyde, 2005, s. 7-9. [Conference on New Approaches to Drug Delivery "Nanomedicines of the Future". Glasgow (GB), 18.11.2005] R&D Projects: GA MŠk 1M0505 Institutional research plan: CEZ:AV0Z40500505 Keywords : biodegradable polymers * drug carriers Subject RIV: EI - Biotechnology ; Bionics

  6. Biodegradation of acetanilide herbicides acetochlor and butachlor in soil.

    Science.gov (United States)

    Ye, Chang-ming; Wang, Xing-jun; Zheng, He-hui

    2002-10-01

    The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matter addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soil-SDBS mixtures and soil-HA mixtures were 4.6 d, 6.1 d and 5.4 d and 5.3 d, 4.9 d and 5.3 d respectively. The biodegradation products were hydroxyacetochlor and 2-methyl-6-ethylaniline for acetochlor, and hydroxybutachlor and 2,6-diethylaniline for butachlor. PMID:12491727

  7. Improving the biodegradative capacity of subsurface bacteria

    International Nuclear Information System (INIS)

    The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates

  8. Biodegradation of natural oils in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Al-Darbi, M.M.; Saeed, N.O.; Islam, M.R. [Dalhousie University, Halifax, NS (Canada). Faculty of Engineering; Lee, K. [Bedford Institute of Oceanography, Dartmouth, NS (Canada)

    2005-01-15

    Spills of non-petroleum hydrocarbons including oils and fish oils are of environmental concern because of their potential to cause serious effects on marine life and coastal environments. Biodegradation by indigenous microorganisms is an important and potentially ubiquitous process affecting both the chemical composition and physical properties of contaminant oils. Data on the environmental persistence of non-petroleum oils is now required for risk assessments and decision making by spill responders. This article investigates the biodegradability of various vegetable and fish oils under the influence of natural bacteria in seawater. The influence of nutrients and microbial environment on changes in bacterial numbers and the extent and rate of degradation for various test oils (olive, mustard, canola and cod liver oils) were studied over time. Time-series visual and microscopic observations were made to characterize physical changes in the residual oils, formation of floating and precipitate particles, oil droplets and dispersion. The biodegradation process was significantly influenced by environmental conditions, with a higher rate and extent of biodegradation observed in seawater amended with nutrients and wastewater that contained elevated numbers of bacteria and nutrients. It was observed that different oils respond in different rates and extents to biodegradation depending on their stability, viscosity and compositions. All results clearly revealed a significant response of the oil-contaminated samples to both the seawater and wastewater environments. Observations on changes in the physical properties of the residual oil may be important in the context of oil spill response strategies. For example, simple physical recovery methods may be used to recover polymeric lumps at the sea surface. (author)

  9. Improving the biodegradative capacity of subsurface bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Romine, M.F.; Brockman, F.J.

    1993-04-01

    The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates.

  10. Hydrocarbons biodegradation in unsaturated porous medium

    International Nuclear Information System (INIS)

    Biological processes are expected to play an important role in the degradation of petroleum hydrocarbons in contaminated soils. However, factors influencing the kinetics of biodegradation are still not well known, especially in the unsaturated zone. To address these biodegradation questions in the unsaturated zone an innovative experimental set up based on a physical column model was developed. This experimental set up appeared to be an excellent tool for elaboration of a structured porous medium, with well defined porous network and adjusted water/oil saturations. Homogeneous repartition of both liquid phases (i.e., aqueous and non aqueous) in the soil pores, which also contain air, was achieved using ceramic membranes placed at the bottom of the soil column. Reproducible interfaces (and connectivity) are developed between gas, and both non mobile water and NAPL phases, depending on the above-defined characteristics of the porous media and on the partial saturations of these three phases (NAPL, water and gas). A respirometric apparatus was coupled to the column. Such experimental set up have been validated with hexadecane in dilution in an HMN phase. This approach allowed detailed information concerning n-hexadecane biodegradation, in aerobic condition, through the profile of the oxygen consumption rate. We have taken benefit of this technique, varying experimental conditions, to determine the main parameters influencing the biodegradation kinetics and compositional evolution of hydrocarbons, under steady state unsaturated conditions and with respect to aerobic metabolism. Impacts of the nitrogen quantity and of three different grain sizes have been examined. Biodegradation of petroleum cut, as diesel cut and middle distillate without aromatic fraction, were, also studied. (author)

  11. Effect of blade vibration on mulch tillage performance under silt clay loam soil

    Directory of Open Access Journals (Sweden)

    B Goudarzi

    2015-09-01

    Full Text Available Introduction: Mulch tillage system is an intermediate system which covers some of disadvantages of no tillage and conventional tillage systems. In farms in which tillage is done with a chisel plow, runoff and soil erosion have a less important relation to moldboard and disk plow and naturally absorption of rainfall will be developed. Thus, the mulch tillage system is an appropriate alternative to conventional tillage and no tillage (Backingham and Pauli, 1993. The unwanted vibration in machinery and industry mainly processes most harmful factors, for example: bearing wear, cracking and loosening joints. And noise is produced in electrical systems by creating a short circuit (Wok, 2011. Self-induced and induced vibration are used in tillage systems. Induced vibration is created by energy consumption and self-induced vibration is created by collision among the blades and soil at the shank (Soeharsono and Setiawan, 2010. A study by Mohammadi-gol et al. (2005 was conducted. It was found that on the disk plow, plant residues maintained on the soil are more than that of moldboard plow. 99% frequency and amplitude, speed and rack angle of blade directly affect soil inversion and indirectly affect preservation of crop residue on the soil. The effect of vibration frequency and rack angle of blade to reduce the tensile strength is also clear. Moreover, in contrast to previous studies when speed progressing is less than (λ, not only the relative speed (λ, but also frequency can reduce the tensile strength (Beiranvand and Shahgoli, 2010; Awad-Allah et al., 2009. Therefore, aim of this study was to determine the effect of vibration and the speed of tillage on soil parameters and drawbar power in using electric power. Materials and Methods: To perform this test, three different modes of vibration (fixed, variable and induced vibration and two levels of speed in real terms at a depth of 20 cm were used for farming. The test was performed with a split plot

  12. Influence of double cropping on growth and yield of dry beans with colored plastic mulches Influencia del doble cultivo en el crecimiento y rendimiento de frijol con cubierta plástica de colores

    OpenAIRE

    Luis Ibarra-Jiménez; Luis Alonso Valdez-Aguilar; Antonio Cárdenas-Flores; Hugo Lira-Saldivar; Javier Lozano-del Río; Carlos Lozano Cavazos

    2012-01-01

    There are numerous studies of the use of plastic mulches in vegetable production, but there is little documentation of their use with dry beans (Phaseolus vulgaris L.) in single and double cropping. The objective of this study was to grow dry beans over two consecutive growing seasons using the same plastic mulch of different colors and examine the influence of soil temperature on growth and yield. The experiment was conducted in Saltillo, Coahuila, Mexico, in the spring and summer of 2008. T...

  13. Inhibiton of Yellow Nutsedge (Cyperus esculentus L. and Bermudagrass (Cynodon dactylon (L. Pers by a Mulch Derived from Rye (Secale cereale L. in grapevines Inhibición del Crecimiento de Chufa (Cyperus esculentus L. y Pasto Bermuda (Cynodon dactylon (L. Pers. con mulch Vegetal Proveniente de Centeno (Secale cereale L. en Vides

    Directory of Open Access Journals (Sweden)

    Juan Ormeño-Núñez

    2008-09-01

    Full Text Available Two field trials (Los Andes 1998-1999 and Santiago 2004-2005 were carried out to determine growth inhibition of yellow nutsedge (Cyperus esculentus L. and bermudagrass (Cynodon dactylon (L. Pers., growing on the plantation row, by mulch derived from a rye (Secale cereale L. cover crop established between grapevine (Vitis vinifera L. rows on overhead (cv. Flame Seedless and vertical (cv. Cabernet Sauvignon training. Spring mowing of the rye sown in the fall allowed for developing a thick and long lasting mulch along the grape rows. Nutsedge and bermudagrass control was 81 and 82%, respectively, and was more effective than conventional chemical (in the row + mechanical (between rows control. Glyphosate at 2% for nutsedge and 1% for bermudagrass control, applied twice (October and December, was insufficient to control either perennial weed adequately. Total broadleaved and grass/sedge weed control was 67.3 and 43.0% more effective with the rye mulch than with conventional treatments at Los Andes and Santiago, respectively. Perennial weed control levels could be explained as the new foliage of yellow nutsedge and bermudagrass was particularly susceptible to the shading provided by the rye mulch assembled prior to mid spring shoot emergence, and this effect remained active up until the beginning of autumn. The subsequent rye foliage mowing at the vegetative stage fully expressed the allelopathic effect produced by this local rye cultivar. The use of rye cover crop management and mulch could be applied as an effective weed control technique in conventional, as well as organic deciduous tree orchards.En dos ensayos de campo (Los Andes 1998-1999 y Santiago 2004-2005 se determinó el efecto inhibitorio sobre chufa (Cyperus esculentus L. y pasto bermuda (Cynodon dactylon (L. Pers. de residuos de centeno (Secale cereale L. establecido en otoño entre las hileras de vides (Vitis vinifera L. en parronal (cv. Flame Seedless y espaldera (cv. Cabernet Sauvignon

  14. Yield Potential of Soil Water and Its Sustainability for Dryland Spring Maize with Plastic Film Mulch on the Loess Plateau

    Science.gov (United States)

    Lin, Wen; Liu, Wenzhao

    2016-04-01

    Plastic film mulch(PM) is an agronomic measure widely used in the dryland spring maize production system on the Loess Plateau of China. The measure can greatly increase yield of dryland maize due to its significant effects on soil water conservation. Few researches have been done to investigate how the yield potential is impacted by PM. The yield-water use (ET) boundary equation raised by French and Schultz provides a simple approach to calculate crop water limited yield potential and gives a benchmark for farmers in managing their crops. However, method used in building the equation is somewhat arbitrary and has no strict principle, which leads to the uncertainty of equation when it is applied. Though using PM can increase crop yield, it increases soil temperature, promotes crop growth and increases the water transpired by crop, which further leads to high water consumption as compared with crops without PM. This means that PM may lead to the overuse of soil water and hence is unsustainable in a long run. This research is mainly focused on the yield potential and sustainability of PMing for spring maize on the Loess Plateau. A principle that may be utilized by any other researchers was proposed based on French & Schultz's boundary equation and on part of quantile regression theory. We used a data set built by collecting the experimental data from published papers and analyzed the water-limited yield potential of spring maize on the Loess Plateau. Moreover, maize yield and soil water dynamics under PM were investigated by a long-term site field experiment. Results show that on the Loess Plateau, the water limited yield potential can be calculated using the boundary equation y = 60.5×(x - 50), with a platform yield of 15954 kghm-2 after the water use exceeds 314 mm. Without PMing, the water limited yield potential can be estimated by the boundary equation y = 47.5×(x - 62.3) , with a platform yield of 12840 kghm-2 when the water use exceeds 325 mm, which

  15. Material Safety Data Sheets (MSDS)

    CERN Document Server

    Lalley, J

    About 250.000 Material Safety Data sheets from the U.S. Government Department of Defense MSDS database, a mirror of data from siri.uvm.edu, MSDS sheets maintained by Cornell University Environmental Health and Safety and other Cornell departments.

  16. Soft Costs Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-05-01

    This fact sheet is an overview of the systems integration subprogram at the U.S. Department of Energy SunShot Initiative. Soft costs can vary significantly as a result of a fragmented energy marketplace. In the U.S., there are 18,000 jurisdictions and 3,000 utilities with different rules and regulations for how to go solar. The same solar equipment may vary widely in its final installation price due to process and market variations across jurisdictions, creating barriers to rapid industry growth. SunShot supports the development of innovative solutions that enable communities to build their local economies and establish clean energy initiatives that meet their needs, while at the same time creating sustainable solar market conditions.

  17. Photovoltaics Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-02-01

    This fact sheet is an overview of the Photovoltaics (PV) subprogram at the U.S. Department of Energy SunShot Initiative. The U.S. Department of Energy (DOE)’s Solar Energy Technologies Office works with industry, academia, national laboratories, and other government agencies to advance solar PV, which is the direct conversion of sunlight into electricity by a semiconductor, in support of the goals of the SunShot Initiative. SunShot supports research and development to aggressively advance PV technology by improving efficiency and reliability and lowering manufacturing costs. SunShot’s PV portfolio spans work from early-stage solar cell research through technology commercialization, including work on materials, processes, and device structure and characterization techniques.

  18. Systems Integration Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    This fact sheet is an overview of the Systems Integration subprogram at the U.S. Department of Energy SunShot Initiative. The Systems Integration subprogram enables the widespread deployment of safe, reliable, and cost-effective solar energy technologies by addressing the associated technical and non-technical challenges. These include timely and cost-effective interconnection procedures, optimal system planning, accurate prediction of solar resources, monitoring and control of solar power, maintaining grid reliability and stability, and many more. To address the challenges associated with interconnecting and integrating hundreds of gigawatts of solar power onto the electricity grid, the Systems Integration program funds research, development, and demonstration projects in four broad, interrelated focus areas: grid performance and reliability, dispatchability, power electronics, and communications.

  19. Controlled morphology of biodegradable polymer blends

    Science.gov (United States)

    Buddhiranon, Sasiwimon; Kyu, Thein

    2009-03-01

    Phase diagrams of biodegradable polymer blends containing poly(ɛ-caprolactone) (PCL) and poly(d,l-lactic acid) (PDLLA) having two different molecular weights were established by means of cloud point measurement and differential scanning calorimetry. Subsequently, the theoretical phase diagram was calculated self-consistently based on the combination of Flory-Huggins free energy for liquid-liquid phase separation and phase field free energy for crystal solidification. The phase diagrams thus obtained were LCST type or hour-glass type, which depended on molecular weight of PDLLA utilized. Guided by the phase diagram, the emerged morphology was determined as a function of blend concentration and temperature. It appears that the morphology control is feasible that ultimately affects the end-use property of PCL/PDLLA blends. A wide variety of morphology of biodegradable polymer may be developed with the porous structure and pore size to control scaffold porosity and the rate of drug delivery.

  20. Starch-based completely biodegradable polymer materials

    Directory of Open Access Journals (Sweden)

    2009-06-01

    Full Text Available Starch is a natural polymer which possesses many unique properties and some shortcoming simultaneously. Some synthetic polymers are biodegradable and can be tailor-made easily. Therefore, by combining the individual advantages of starch and synthetic polymers, starch-based completely biodegradable polymers (SCBP are potential for applications in biomedical and environmental fields. Therefore it received great attention and was extensively investigated. In this paper, the structure and characteristics of starch and some synthetic degradable polymers are briefly introduced. Then, the recent progress about the preparation of SCBP via physical blending and chemical modification is reviewed and discussed. At last, some examples have been presented to elucidate that SCBP are promising materials for various applications and their development is a good solution for reducing the consumption of petroleum resources and environmental problem.

  1. Biodegradable Epoxy Networks Cured with Polypeptides

    Science.gov (United States)

    Nakamura, Shigeo; Kramer, Edward J.

    2006-03-01

    Epoxy resins are used widely for adhesives as well as coatings. However, once cured they are usually highly cross-linked and are not biodegradable. To obtain potentially biodegradable polypeptides that can cure with epoxy resins and achieve as good properties as the conventional phenol novolac hardeners, poly(succinimide-co-tyrosine) was synthesized by thermal polycondensation of L-aspartic acid and L-tyrosine with phosphoric acid under reduced pressure. The tyrosine/succinimide ratio in the polypeptide was always lower than the tyrosine/(aspartic acid) feed ratio and was influenced by the synthesis conditions. Poly(succinimide-tyrosine- phenylalanine) was also synthesized from L-aspartic acid, L- tyrosine and L-phenylalanine. The thermal and mechanical properties of epoxy resins cured with these polypeptides are comparable to those of similar resins cured with conventional hardeners. In addition, enzymatic degradability tests showed that Chymotrypsin or Subtilisin A could cleave cured films in an alkaline borate buffer.

  2. Modelling the Antarctic Ice Sheet

    DEFF Research Database (Denmark)

    Pedersen, Jens Olaf Pepke; Holm, A.

    2015-01-01

    Science) Antarctic Ice Sheet (DAIS) model (Shaffer 2014) is forced by reconstructed time series of Antarctic temperature, global sea level and ocean subsurface temperature over the last two glacial cycles. In this talk a modelling work of the Antarctic ice sheet over most of the Cenozoic era using the......The Antarctic ice sheet is a major player in the Earth’s climate system and is by far the largest depository of fresh water on the planet. Ice stored in the Antarctic ice sheet (AIS) contains enough water to raise sea level by about 58 m, and ice loss from Antarctica contributed significantly to...... DAIS model will be presented. G. Shaffer (2014) Formulation, calibration and validation of the DAIS model (version 1), a simple Antarctic ice sheet model sensitive to variations of sea level and ocean subsurface temperature, Geosci. Model Dev., 7, 1803‐1818...

  3. Vitamin and Mineral Supplement Fact Sheets

    Science.gov (United States)

    ... Tables Online DRI Tool Daily Value (DV) Tables Vitamin and Mineral Supplement Fact Sheets Search the list ... Supplements: Background Information Botanical Dietary Supplements: Background Information Vitamin and Mineral Fact Sheets Botanical Supplement Fact Sheets ...

  4. Anaerobic Biodegradability of Agricultural Renewable Fibers

    OpenAIRE

    Shi, Bo; Lortscher, Peter; Palfery, Doris

    2013-01-01

    Natural fiber-based paper and paperboard products are likely disposed of in municipal wastewater, composting, or landfill after an intended usage. However, there are few studies reporting anaerobic sludge digestion and biodegradability of agricultural fibers although the soiled sanitary products, containing agricultural fibers, are increasingly disposed of in municipal wastewater or conventional landfill treatment systems, in which one or more unit operations are anaerobic digestion. We condu...

  5. Assessment of polymer-based nanocomposites biodegradability

    OpenAIRE

    Machado, A.V.; Araújo, Andreia Isabel Silva; Oliveira, Manuel

    2015-01-01

    The management of solid waste is a growing concern in many countries. Municipal solid waste is a major component of the total solid waste generated by society, and the composting of municipal solid waste has gained some attention even though a composting treatment for it is not yet widespread. It may not be realistic to replace large portions of these plastics with biodegradable materials, and it may be more important to separate plastics unsuitable for the composting process at the generatin...

  6. Biodegradation of Petroleum Hydrocarbons in Soil

    OpenAIRE

    MR Mehrasbi; B Haghighi; M.Shariat; S Naseri; Naddafi, K

    2003-01-01

    Biodegradation of petroleum hydrocarbons (20 g/kg dw soil) was investigated in 3 media, differing in the kind of petroleum fractions. In the laboratory experiments, during 5 months, the activities of petroleum hydrocarbon-degrading microorganisms and dehydrogenase activity of soil was determined. Gas chromatographic analysis showed the biological decontaminations for gas oil, kerosene and synthetic mixture (gas oil, kerosene and furnace oil) are 60 %, 36 % and 55 %, respectively. Dehydrogenas...

  7. Nanomembranes and nanofibers from biodegradable conducting polymers

    OpenAIRE

    Jordi Puiggalí; Carlos Alemán; Luís Javier del Valle; Elaine Armelin; María del Mar Pérez-Madrigal; Elena Llorens

    2013-01-01

    This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e. g., aliphatic polyesters such as polylactide or polycaprolactone) and conducting polymers (e. g., polyaniline, polypirrole or polythiophenes). These materials have potential biomedical applications (e. g., tissue engineering or drug delivery systems) and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their correspon...

  8. Biodegradation of tert-butylphenyl diphenyl phosphate

    International Nuclear Information System (INIS)

    The biodegradation of tert-butylphenyl diphenyl phosphate (BPDP) was examined in microcosms containing sediment and water from five different ecosystems as part of studies to elucidate the environmental fate of phosphate ester flame retardants. Biodegradation of [14C]BPDP was monitored in the environmental microcosms by measuring the evolution of 14CO2. Over 37% of BPDP was mineralized after 8 weeks in microcosms from an ecosystem which had chronic exposure to agricultural chemicals. In contrast, only 1.7% of BPDP was degraded to 14CO2 in samples collected from a noncontaminated site. The exposure concentration of BPDP affected the percentage which was degraded to 14CO2 in microcosms from the two most active ecosystems. Mineralization was highest at a concentration of 0.1 mg of BPDP and was inhibited with 10- and 100-fold higher concentrations of BPDP. The authors observed adaptive increases in both microbial populations and phosphoesterase enzymes in some sediments acclimated to BPDP. Chemical analyses of the residues in the microcosms indicated undegraded BPDP and minor amounts of phenol, tert-butylphenol, diphenyl phosphate, and triphenyl phosphate as biodegradation products. These data suggest that the microbial degradation of BPDP results from at least three catabolic processes and is highest when low concentrations of BPDP are exposed to sediment microorganisms of eutrophic ecosystems which have high phosphotri- and diesterase activities and previous exposure to anthropogenic chemicals

  9. Nanomembranes and Nanofibers from Biodegradable Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Jordi Puiggalí

    2013-09-01

    Full Text Available This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e.g., aliphatic polyesters such as polylactide or polycaprolactone and conducting polymers (e.g., polyaniline, polypirrole or polythiophenes. These materials have potential biomedical applications (e.g., tissue engineering or drug delivery systems and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their corresponding individual components. Systems based on biodegradable and conducting polymers constitute nowadays one of the most promising solutions to develop advanced materials enable to cover aspects like local stimulation of desired tissue, time controlled drug release and stimulation of either the proliferation or differentiation of various cell types. The first sections of the review are focused on a general overview of conducting and biodegradable polymers most usually employed and the explanation of the most suitable techniques for preparing nanofibers and nanomembranes (i.e., electrospinning and spin coating. Following sections are organized according to the base conducting polymer (e.g., Sections 4–6 describe hybrid systems having aniline, pyrrole and thiophene units, respectively. Each one of these sections includes specific subsections dealing with applications in a nanofiber or nanomembrane form. Finally, miscellaneous systems and concluding remarks are given in the two last sections.

  10. Biodegradation of ion-exchange media

    International Nuclear Information System (INIS)

    Ion-exchange media, both bead resins and powdered filter media, are used in nuclear power plants to remove radioactivity from process water prior to reuse or environmental discharge. Since the ion- exchange media are made from synthetic hydrocarbon-based polymers, they may be susceptible to damage from biological activity. The purpose of this study was to investigate some of the more basic aspects of biodegradation of ion-exchange media, specifically to evaluate the ability of microorganisms to utilize the ion-exchange media or materials sorbed on them as a food source. The ASTM-G22 test, alone and combined with the Bartha Pramer respirometric method, failed to indicate the biodegradability of the ion-exchange media. The limitation of these methods was that they used a single test organism. In later phases of this study, a mixed microbial culture was grown from resin waste samples obtained from the BNL High Flux Beam Reactor. These microorganisms were used to evaluate the susceptibility of different types of ion-exchange media to biological attack. Qualitative assessments of biodegradability were based on visual observations of culture growths. Greater susceptibility was associated with increased turbidity in solution indicative of bacterial growth, and more luxuriant fungal mycelial growth in solution or directly on the ion-exchange resin beads. 21 refs., 9 figs., 18 tabs

  11. Titanate nanotube coatings on biodegradable photopolymer scaffolds

    International Nuclear Information System (INIS)

    Rigid, biodegradable photopolymer scaffolds were coated with titanate nanotubes (TNTs) by using a spin-coating method. TNTs were synthesized by a hydrothermal process at 150 °C under 4.7 bar ambient pressure. The biodegradable photopolymer scaffolds were produced by mask-assisted excimer laser photocuring at 308 nm. For scaffold coating, a stable ethanolic TNT sol was prepared by a simple colloid chemical route without the use of any binding compounds or additives. Scanning electron microscopy along with elemental analysis revealed that the scaffolds were homogenously coated by TNTs. The developed TNT coating can further improve the surface geometry of fabricated scaffolds, and therefore it can further increase the cell adhesion. Highlights: ► Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. ► Titanate nanotube deposition was carried out without binding compounds or additives. ► The titanate nanotube coating can further improve the surface geometry of scaffolds. ► These reproducible platforms will be of high importance for biological applications

  12. Macmillan ring-free oil biodegradation project

    International Nuclear Information System (INIS)

    Crude oil processing at the Macmillan Ring-Free Oil Company facility (Macmillan Oil Refinery) began in approximately 1929. Operations produced naphtha, diesel fuel, insulating oil, lubricating oil, and asphalt until approximately 1987. The waste material generated by the process was Resource Conservation and Recovery Act (RCRA) listed waste K048-Dissolved Air Flotation (DAF) float containing volatile and semivolatile organic compounds. On-site unlined surface impoundments used to store DAF and crude oil wastes have periodically overflowed and contaminated two adjacent creeks. A series of extensive site investigation activities in 1992 and 1993 addressed tank and drum, asbestos, lagoon and groundwater contamination at the site. The results of the investigation indicated that the majority of the contamination is contained within 10 lagoons and surrounding soils. Volume calculations indicate that approximately 45,000 cubic yards of contaminated soils and sediments required treatment. A field simulation of biodegradation of these wastes in a land treatment unit was implemented during removal actions. Results of the remedy selection biodegradation assessment provided evidence of a 61 to 96 percent reduction in contaminant concentrations. These concentrations are below land disposal and health risk-based criteria. The technology of biodegradation meets the EPA criteria for inclusion in the potential remedies for the Macmillan Oil Refinery

  13. Biodegradation potential of photocatalyzed surfactant washwater.

    Science.gov (United States)

    Maillacheruvu, K; Buck, L; Lee, E

    2001-01-01

    Enhanced release of hydrophobic compounds from a soil matrix can be achieved by use of soil-washing or soil-flushing using various surfactants. However, the surfactants used in achieving the desorption of organic contaminants may also cause a problem in subsequent removal/disposal of these contaminants. UV radiation in the presence of TiO2 as a pre-treatment step to achieve initial (or partial) breakdown of naphthalene and Sodium Dodecyl Sulfate (SDS) using batch experiments indicated that 56% to 88% naphthalene degradation occurred within 30 minutes to one hour. Preliminary results on the estimate of the batch aerobic biodegradation potential of photocatalyzed washwater containing naphthalene and SDS suggested that SDS was the major carbon and energy source for an activated sludge enrichment culture and an enrichment culture obtained from microorganisms at a contaminated site. Continuous-flow stirred tank reactors (CSTRs) with with a solids retention time (SRT) of 4 days were not effective, but an SRT of 8 days was successful in biodegrading the naphthalene and surfactant. These results indicated that photocatalytic treatment as a pre-treatment step followed by a biodegradation step may offer potential in cleaning up surfactant washwaters containing organic contaminants. PMID:11501312

  14. Titanate nanotube coatings on biodegradable photopolymer scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Beke, S., E-mail: szabolcs.beke@iit.it [Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Kőrösi, L. [Department of Biotechnology, Nanophage Therapy Center, Enviroinvest Corporation, Kertváros u. 2, H-7632, Pécs (Hungary); Scarpellini, A. [Department of Nanochemistry, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Anjum, F.; Brandi, F. [Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy)

    2013-05-01

    Rigid, biodegradable photopolymer scaffolds were coated with titanate nanotubes (TNTs) by using a spin-coating method. TNTs were synthesized by a hydrothermal process at 150 °C under 4.7 bar ambient pressure. The biodegradable photopolymer scaffolds were produced by mask-assisted excimer laser photocuring at 308 nm. For scaffold coating, a stable ethanolic TNT sol was prepared by a simple colloid chemical route without the use of any binding compounds or additives. Scanning electron microscopy along with elemental analysis revealed that the scaffolds were homogenously coated by TNTs. The developed TNT coating can further improve the surface geometry of fabricated scaffolds, and therefore it can further increase the cell adhesion. Highlights: ► Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. ► Titanate nanotube deposition was carried out without binding compounds or additives. ► The titanate nanotube coating can further improve the surface geometry of scaffolds. ► These reproducible platforms will be of high importance for biological applications.

  15. 覆盖对喷灌夏玉米植株生长和产量的影响%Effects of Mulching on Plant Growth and Yield of Summer Maize under Sprinkler Irrigation

    Institute of Scientific and Technical Information of China (English)

    刘小飞; 孙景生; 刘祖贵; 王景雷; 张寄阳; 张俊鹏

    2011-01-01

    75%, 65% and 55% of irrigation controlling lower limit were set up during the growing period of summer maize, effects of plastic film mulching and different quantity of straw mulching on growth, yield, water consumption and water use efficiency (WUE) of maize under sprinkler irrigation were studied. The results showed that plastic film mulching could significantly promote the growth of plants, and had the similar effects of yield increasing compared with the high quantity of straw mulching(more than 7 500 kg/ha). The yield increasing rate of plastic film mulching and straw mulching increased with the decrease of soil moisture. The water consumption of summer maize was the smallest in plastic film mulching treatment and the largest in non-mulching treatment. Water consumption of summer maize in the straw mulching treatment had a reduced tendency with the increase of straw cover quantity. The higher soil moisture was the more water-saving of mulching. Water use efficiency (WUE) of plastic film mulching was the highest, and increased by more than 50% compared with non mulching treatment. WUE of straw mulching treatment increased with straw mulching quantity. When straw mulching quantity reached 7 500 kg/ha, the WUE increased a little.%在夏玉米生育期间设75%、65%、55%田间持水量3个灌水控制下限,研究地膜覆盖和不同秸秆覆盖量对喷灌夏玉米生长发育、产量、耗水量及水分利用效率的影响.结果表明,地膜覆盖能明显促进植株的生长,地膜覆盖和秸秆覆盖量大于7 500kg/hm2处理的增产效果相当,覆盖增产效果均随着土壤水分的降低而增加.地膜覆盖处理耗水量最小,无覆盖的最大;秸秆覆盖处理的耗水量随着覆盖量的增加呈减少趋势,土壤水分越高的处理,覆盖节水量越多.地膜覆盖处理的水分利用效率(WUE)最高,比不覆盖处理提高50%以上;秸秆覆盖处理的WUE随着覆盖量的增加而增加,当覆盖量达到7 500kg/hm时,WUE的增加幅度变小.

  16. Biodegradability evaluation of polymers by ISO 14855-2.

    Science.gov (United States)

    Funabashi, Masahiro; Ninomiya, Fumi; Kunioka, Masao

    2009-10-01

    Biodegradabilities of polymers and their composites in a controlled compost were described. Polycaprolactone (PCL) and poly(lactic acid) (PLA) were employed as biodegradable polymers. Biodegradabilities of PCL and PLA samples in a controlled compost were measured using a Microbial Oxidative Degradation Analyzer (MODA) according to ISO 14855-2. Sample preparation method for biodegradation test according to ISO/DIS 10210 was also described. Effects of sizes and shapes of samples on biodegradability were studied. Reproducibility of biodegradation test of ISO 14855-2 by MODA was confirmed. Validity of sample preparation method for polymer pellets, polymer film, and polymer products of ISO/DIS 10210 for ISO 14855-2 was confirmed. PMID:20111676

  17. Biodegradable materials as binders for IVth generation moulding sands

    Directory of Open Access Journals (Sweden)

    K. Major-Gabry

    2015-09-01

    Full Text Available This paper focuses on the possibility of using the biodegradable materials as binders (or parts of binders?compositions for foundry moulding and core sands. Results showed that there is a great possibility of using available biodegradable materials as foundry moulding sand binders. Using biodegradable materials as partial content of new binders, or additives to moulding sands may not only decrease the toxicity and increase reclamation ability of tested moulding sands, but also accelerate the biodegradation rate of used binders, and the new biodegradable additive (PCL did not decrease the strength and thermal properties. In addition, using polycaprolactone (PCL as a biodegradable material may improve the flexibility of moulding sands with polymeric binder and reduce toxicity.

  18. Degradation of Oxo-Biodegradable Plastic by Pleurotus ostreatus

    OpenAIRE

    José Maria Rodrigues da Luz; Sirlaine Albino Paes; Mateus Dias Nunes; Marliane de Cássia Soares da Silva; Maria Catarina Megumi Kasuya

    2013-01-01

    Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ul...

  19. Processing and characterization of extruded zein-based biodegradable films

    Science.gov (United States)

    Wang, Ying

    The objectives of this study were to prepare biodegradable zein films by extrusion processing and to evaluate relevant physical properties of resulting films with respect to their potential as packaging materials. The manufacture of protein-based packaging films by extrusion has remained a challenge. In this study, a zein resin was prepared by combining zein and oleic acid. This resin was formed into films by blown extrusion at the bench-top scale. Resin moisture content and extruder barrel temperature profile were identified as major parameters controlling the process. The optimum temperature of the blowing head was determined to be 40--45°C, while optimum moisture at film collection was 14--15%. Physico-chemical properties of the extruded products were characterized. Extruded products exhibited plastic behavior and ductility. Morphology characterization by SEM showed micro voids in extruded zein sheets, caused by entrapped air bubbles or water droplets. DSC characterization showed that zein was effectively plasticized by oleic acid as evidenced by the lowered glass transition temperature of zein films. X-ray scattering was used to investigate changes in zein molecular aggregation during processing. It was observed that higher mechanical energy treatment progressively disrupted zein molecular aggregates, resulting in a more uniform distribution of individual zein molecules. With the incorporation of oleic acid as plasticizer and monoglycerides as emulsifier, zein formed structures with long-range periodicity which varied depending on the formulation and processing methods. Processing methods for film formation affected the binding of oleic acid to zein with higher mechanical energy treatment resulting in better interaction between the two components. The moisture sorption capacity of extruded zein films was reduced due to the compact morphology caused by extrusion. Plasticization with oleic acid further reduced moisture sorption of zein films. The overall

  20. Biodegradation of flax fiber reinforced poly lactic acid

    Directory of Open Access Journals (Sweden)

    2010-07-01

    Full Text Available Woven and nonwoven flax fiber reinforced poly lactic acid (PLA biocomposites were prepared with amphiphilic additives as accelerator for biodegradation. The prepared composites were buried in farmland soil for biodegradability studies. Loss in weight of the biodegraded composite samples was determined at different time intervals. The surface morphology of the biodegraded composites was studied with scanning electron microscope (SEM. Results indicated that in presence of mandelic acid, the composites showed accelerated biodegradation with 20–25% loss in weight after 50–60 days. On the other hand, in presence of dicumyl peroxide (as additive, biodegradation of the composites was relatively slow as confirmed by only 5–10% loss in weight even after 80–90 days. This was further confirmed by surface morphology of the biodegraded composites. We have attempted to show that depending on the end uses, we can add different amphiphilic additives for delayed or accelerated biodegradability. This work gives us the idea of biodegradation of materials from natural fiber reinforced PLA composites when discarded carelessly in the environment instead of proper waste disposal site.

  1. Silicon microneedles array with biodegradable tips for transdermal drug delivery

    CERN Document Server

    Chen, B; Tay, Francis; Wong, Y T; Iliescu, C

    2008-01-01

    This paper presents the fabrication process, characterization results and basic functionality of silicon microneedles array with biodegradable tips. In order to avoid the main problems related to silicon microneedles : broking of the top part of the needles inside the skin, a simple solution can be fabrication of microneedles array with biodegradable tips. The silicon microneedles array was fabricated by using reactive ion etching while the biodegradable tips were performed using and anodization process that generates selectively porous silicon only on the top part of the skin. The paper presents also the results of in vitro release of calcein using microneedles array with biodegradable tips

  2. Critical evaluation of biodegradable polymers used in nanodrugs.

    Science.gov (United States)

    Marin, Edgar; Briceño, Maria Isabel; Caballero-George, Catherina

    2013-01-01

    Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, flexibility, and minimal side effects. Applications of these materials include creation of skin, blood vessels, cartilage scaffolds, and nanosystems for drug delivery. These biodegradable polymeric nanoparticles enhance properties such as bioavailability and stability, and provide controlled release of bioactive compounds. This review evaluates the classification, synthesis, degradation mechanisms, and biological applications of the biodegradable polymers currently being studied as drug delivery carriers. In addition, the use of nanosystems to solve current drug delivery problems are reviewed. PMID:23990720

  3. Influence of inorganic salt on aerobic biodegradability of dyestuffs

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    this paper, the influence of inorganic salt on aerobic biodegradability of dyestuffs was studied by means of semicontinuous activated sludge method. It was found that: biodegradability of dyestuffs would decrease with the increase of the concentration of NaCl; however, biodegradability in the condition of NaCl = 30 g/L was better than that in the condition of NaCl =15 g/L; in the three NaCl conditions, biodegradability of tasted dyestuffs followed the following order: NaCl= 0 g/L > NaCl= 30g/L>NaCl= 15 g/L.

  4. Predicting the effectiveness of different mulching techniques to reduce post-fire runoff and erosion in Mediterranean pine stands - does cover matter?

    Science.gov (United States)

    Vieira, Diana; Nunes, João; Prats, Sergio; Serpa, Dalila; Keizer, Jan

    2016-04-01

    Wildfires have become a recurrent threat for many forest ecosystems of the Mediterranean. The characteristics of the Mediterranean climate with its warm and dry summers and mild and wet winters make it prone to wildfire occurrence as well as to post-fire soil erosion. Furthermore, climate change and continuation of current land management practices and planning are generally expected to further increase this threat. The wide recognition of the effects of wildfires to enhance runoff and erosion has created a strong demand for model-based tools for predicting the post-fire hydrological and erosion response and, in particular, for predicting the effectiveness of post-fire forestry operations to mitigate these responses. Such a tool should allow to identify areas with elevated risks of soil erosion and to evaluate which measures should be applied and when to minimize these risks. A key element in evaluating these measures is also their costs, in order to optimize the use of the limited resources that are typically available for post-fire land management. In this study, two "treatments" are compared with control conditions (i.e. doing nothing) after a wildfire with a moderate soil burn severity: (i) 4 erosion plots were treated with hydro-mulch, (ii) 4 erosion plots were untreated but had a high pine needle cover quickly after the fire, due to needle cast from scorched pine crowns (often referred to as "natural mulching") (iii) 4 plots were untreated and had a very reduced protective litter cover . The main objective of this study was to asses if the revised MMF model could effectively predict the impacts of hydro-mulching and natural mulching with pine needle on runoff generation and the associated soil losses. If MMF could predict well the impact of natural mulching, it could be very useful in limiting the areas that should be considered for specific soil mitigation measures, especially in the case of wildfires that affect large areas with moderate severity. The

  5. Effects of Different Mulching Methods on Water Use Efficiency of Mung Bean%不同覆盖方式对绿豆水分利用效率的影响

    Institute of Scientific and Technical Information of China (English)

    纪晓玲; 岳鹏鹏; 张静; 刘建华; 雷锦银; 张雄

    2011-01-01

    绿豆是陕北旱区特色经济作物和主要农作物之一,探索适合地区特色的绿豆高产抗旱栽培技术对完善该区小杂粮栽培模式和提高区域农业水平意义重大。通过田间试验,设置垄膜覆盖、双沟覆膜、全膜覆盖、秸秆覆盖和露地5种处理,分析了不同覆盖方式对绿豆土壤温度、耗水量、水分利用效率、生长和经济性状以及产量的影响。结果表明,地膜覆盖对陕北地区绿豆增产效果极为显著,秸秆覆盖可提高水分利用效率,但同时降低地温,增产作用不明显。3种地膜覆盖方式中,又以垄膜覆盖方式提高水分利用效率和增加绿豆产量的效果最好,且操作简单,在陕北地区绿豆抗旱%Mung bean is one of the most important economic crops and traditional crops in Northern Shaanxi Province.Developing drought-resistant mung bean cultivation techniques suitable for regional characteristics is the essential part for optimizing the cultivation models for minor grain crops and improving the regional agriculture.Five treatments were set up,including plastic film mulching on ridge,plastic film mulching on "W" shape ridge,plastic film mulching on whole plot,straw mulching on whole plot and no mulching as control.Comparing soil temperature,water consumption,water use efficiency,plant characters and yield of mung bean in different treatments,the results show that plastic film mulching significantly increased the yield of mung bean and the straw mulching did not.In the three plastic film mulching treatments,plastic film mulching on ridge was the most effective treatment in improving both water use efficiency and yield of mung bean.Owing to its additional simplicity of its installation,the plastic film mulching on ridge should be considered as the first option as the drought resistant cultivation technique of mung bean in Northern Shaanxi Province.

  6. 地膜覆盖对农田径流中氮磷流失的影响%The Effected of Mulch Film on Nitrogen and Phosphorus Loss in Agricultural Runoff

    Institute of Scientific and Technical Information of China (English)

    邓伟; 许振成; 吴根义; 贺德春

    2011-01-01

    [ Objective] The aim of the study was to seek a good way to reduce nitrogen and phosphorus loss in agricultural runoff. [ Method] The effect of three kinds of mulch film: plastic film mulching, straw mulching,none mulching on nitrogen and phosphorus loss in agriculture was investigated. [Result]The results showed that: Although mulching increased runoff,reduced the rains washed out planting soil,so the concentration and total loss of nitrogen and phosphorus in runoff was lowered; The land of plastic film mulching add more runoff,but total loss of nitrogen and phosphorus was lowest; The land of straw mulching had a little more total loss of nitrogen and phosphorus then the land of plastic film mulching,but the output of crops was higher then the land of plastic film mulching and none secondarypollutant. [ Conclusion] Straw mulching could reduce nitrogen and phosphorus loss in agricultural runoff, improve the output of crops and no secondarypollutant emission. So straw was a good cultivated ways.%[目的]减少农田氮磷的径流流失.[方法]研究3种不同地膜覆盖:塑料覆盖,桔杆覆盖和无覆盖方式对农田氮磷径流流失的影响.[结果]地膜覆盖增加了径流量,但减少了雨水对种植土壤的冲刷,降低了径流中氮磷的浓度,从而减少了径流中氮磷的流失;塑料薄膜覆盖地块增加的径流较多,但氮磷流失总量最少;桔秆覆盖地块产生的氮磷流失量略大于塑料薄膜覆盖地块,但作物产量高于塑料薄膜地块,同时不会产生二次污染[结论]桔杆地膜覆盖可以减少农田氮磷的径流流失,增加产量,且不产生二次污染,是较好的农作方式.

  7. Seeing graphene-based sheets

    Directory of Open Access Journals (Sweden)

    Jaemyung Kim

    2010-03-01

    Full Text Available Graphene-based sheets such as graphene, graphene oxide and reduced graphene oxide have stimulated great interest due to their promising electronic, mechanical and thermal properties. Microscopy imaging is indispensable for characterizing these single atomic layers, and oftentimes is the first measure of sample quality. This review provides an overview of current imaging techniques for graphene-based sheets and highlights a recently developed fluorescence quenching microscopy technique that allows high-throughput, high-contrast imaging of graphene-based sheets on arbitrary substrate and even in solution.

  8. Number & operations task & drill sheets

    CERN Document Server

    Reed, Nat

    2011-01-01

    For grades 6-8, our State Standards-based combined resource meets the number & operations concepts addressed by the NCTM standards and encourages the students to review the concepts in unique ways. The task sheets introduce the mathematical concepts to the students around a central problem taken from real-life experiences, while the drill sheets provide warm-up and timed practice questions for the students to strengthen their procedural proficiency skills. Included are problems involving place value, fractions, addition, subtraction and using money. The combined task & drill sheets offer spac

  9. Effects of plastic-film mulching and nitrogen application on forage-oriented maize in the agriculture-animal husbandry ecotone in North China

    Institute of Scientific and Technical Information of China (English)

    Xiong DU; Xiuju BIAN; Weihong ZHANG; Fucun YANG; Lifeng ZHANG

    2008-01-01

    To counter the actual problems of forage shortage and low quality existing in the agriculture-animal husbandry ecotone in North China,a research was conducted to study the effects of plastic-film mulching and nitrogen application on the production of forageoriented maize with the aim of producing water-saving forage with high-yield and good quality.Field experiments combined with laboratory experimental estimation and analysis was adopted.Plastic-film mulching increased the dry biomass of forage-oriented maize by 23.8% with effectively improving the maize's nitrogen absorption so that the apparent utilization ratio and output-input ratio of nitrogen were enhanced.The content of crude protein in maize plant was increased and thus,forage nutritive quality was improved.Plastic-film mulching remodeled the maize field water consumption scheduling pattern and increased the water use efficiency by over 10%.Nitrogen application to forage-oriented maize co-improved the biomass and the nutritive quality with the nutritive matter (percentage and yield) several times of the biomass.Nitrogen application increased maize biomass production by 36.1%-39.5% and it increased the contents of crude protein and crude fat in maize plant by 109% and 145%,respectively.The yields of the two nutritive matters increased by 160% and 210%.Nitrogen application at the were considered as the most proper rates to guarantee high yield and good quality of forage-oriented maize and were the rates to keep the available nitrogen balanced in the soil.Plastic-film mulching and nitrogen fertilizer application to forage-oriented maize was an effective way of producing forage with high yield and good quality,relieving the shortage of animal forage and acceleratingecological recovery and economic development in this ecotone in North China.

  10. High biomass cover crops and organic mulch effects on yields, soil carbon, and weed populations during no-till herbicide-free collard production

    OpenAIRE

    Mulvaney, Michael J.

    2009-01-01

    This presentation describes dissertation work focusing on conservation agriculture production systems for smallholders and limited input farmers. The research design focuses on the conversion of previously conventionally tilled fields to a no till system and subsequently compares different mulch applications including straw and leguminous plants. The main objective of the research was to study whether herbicide free systems could be productive. Such findings may also have promising impacts fo...

  11. Warmer and Wetter Soil Stimulates Assimilation More than Respiration in Rainfed Agricultural Ecosystem on the China Loess Plateau: The Role of Partial Plastic Film Mulching Tillage.

    Science.gov (United States)

    Gong, Daozhi; Hao, Weiping; Mei, Xurong; Gao, Xiang; Liu, Qi; Caylor, Kelly

    2015-01-01

    Effects of agricultural practices on ecosystem carbon storage have acquired widespread concern due to its alleviation of rising atmospheric CO2 concentrations. Recently, combining of furrow-ridge with plastic film mulching in spring maize ecosystem was widely applied to boost crop water productivity in the semiarid regions of China. However, there is still limited information about the potentials for increased ecosystem carbon storage of this tillage method. The objective of this study was to quantify and contrast net carbon dioxide exchange, biomass accumulation and carbon budgets of maize (Zea maize L.) fields under the traditional non-mulching with flat tillage (CK) and partial plastic film mulching with furrow-ridge tillage (MFR) on the China Loess Plateau. Half-hourly net ecosystem CO2 exchange (NEE) of both treatments were synchronously measured with two eddy covariance systems during the growing seasons of 2011 through 2013. At same time green leaf area index (GLAI) and biomass were also measured biweekly. Compared with CK, the warmer and wetter (+1.3°C and +4.3%) top soil at MFR accelerated the rates of biomass accumulation, promoted greater green leaf area and thus shortened the growing seasons by an average value of 10.4 days for three years. MFR stimulated assimilation more than respiration during whole growing season, resulting in a higher carbon sequestration in terms of NEE of -79 gC/m2 than CK. However, after considering carbon in harvested grain (or aboveground biomass), there is a slight higher carbon sink (or a stronger carbon source) in MFR due to its greater difference of aboveground biomass than that of grain between both treatments. These results demonstrate that partial plastic film mulched furrow-ridge tillage with aboveground biomass exclusive of grain returned to the soil is an effective way to enhance simultaneously carbon sequestration and grain yield of maize in the semiarid regions. PMID:26305354

  12. Warmer and Wetter Soil Stimulates Assimilation More than Respiration in Rainfed Agricultural Ecosystem on the China Loess Plateau: The Role of Partial Plastic Film Mulching Tillage.

    Directory of Open Access Journals (Sweden)

    Daozhi Gong

    Full Text Available Effects of agricultural practices on ecosystem carbon storage have acquired widespread concern due to its alleviation of rising atmospheric CO2 concentrations. Recently, combining of furrow-ridge with plastic film mulching in spring maize ecosystem was widely applied to boost crop water productivity in the semiarid regions of China. However, there is still limited information about the potentials for increased ecosystem carbon storage of this tillage method. The objective of this study was to quantify and contrast net carbon dioxide exchange, biomass accumulation and carbon budgets of maize (Zea maize L. fields under the traditional non-mulching with flat tillage (CK and partial plastic film mulching with furrow-ridge tillage (MFR on the China Loess Plateau. Half-hourly net ecosystem CO2 exchange (NEE of both treatments were synchronously measured with two eddy covariance systems during the growing seasons of 2011 through 2013. At same time green leaf area index (GLAI and biomass were also measured biweekly. Compared with CK, the warmer and wetter (+1.3°C and +4.3% top soil at MFR accelerated the rates of biomass accumulation, promoted greater green leaf area and thus shortened the growing seasons by an average value of 10.4 days for three years. MFR stimulated assimilation more than respiration during whole growing season, resulting in a higher carbon sequestration in terms of NEE of -79 gC/m2 than CK. However, after considering carbon in harvested grain (or aboveground biomass, there is a slight higher carbon sink (or a stronger carbon source in MFR due to its greater difference of aboveground biomass than that of grain between both treatments. These results demonstrate that partial plastic film mulched furrow-ridge tillage with aboveground biomass exclusive of grain returned to the soil is an effective way to enhance simultaneously carbon sequestration and grain yield of maize in the semiarid regions.

  13. Effect of straw mulch residues of previous crop oats on the weed population in direct seeded faba bean in Organic Farming

    Directory of Open Access Journals (Sweden)

    Massucati, Luiz Felipe Perrone

    2014-02-01

    Full Text Available Under conditions of Organic Farming, we investigated whether direct seeding of faba bean (Vicia faba L. into straw mulch from residues of precrop oats used for weed control enables at least occasional/opportunistic direct seeding in Organic Agriculture. Eight field trials were carried out at different study sites in North Rhine-Westphalia, Germany, in 2008-2009 and 2009-2010. Direct seeding (DS was performed into mulch layers of 0,4 and 6 t ha-1 of straw residues applied to the remaining stubble, simulating different yield levels of the precrop oats. LBS was used as a reference treatment, where straw was harvested, stubble tillage performed and seedbed prepared in fall and oil radish (Raphanus sativus grown as winter cover crop. Mouldboard ploughing combined with conventional seedbed preparation was performed in early spring to V. faba. Compared with LBS, straw mulch with subsequent direct seeding suppressed especially dicotyledonous annuals significantly. DS treatments with straw reduced the abundance of this group by 81 and 85% compared with LBS. Straw mulch resulted in effective suppression of photosensitive weeds such as Matricaria spp. and late germinating Chenopodium album. Grasses and perennial species occurred independent of the amount of straw. Compared with DS, the abundance of these weeds was reduced by 64 and 82% in LBS treatment. The shoot dry matter production of faba bean was retarded by DS compared with LBS, but significant yield losses could be avoided with straw residues of at least 4 t ha-1. Sufficient amount of straw of from the previous crop is a key criterion to facilitate organic no-till farming of faba bean in a suitable crop sequence when pressure of perennials and grasses is low.

  14. Response of Soybean [Glycine Max (L. Merrill] to Lime Based Integrated Nutrient Management and Mulching on Nodulation, Nutrient Contents and Yield in Clay Loam Soil.

    Directory of Open Access Journals (Sweden)

    R.C. Jain

    2015-08-01

    Full Text Available The present experiment was laid out in a randomized block design consisted of 6 treatments viz. (T1-Absolute control,(T2 -Farmer practice (50kg DAP/ha,(T3 RDF+ ZnSO4@25 kg/ha+ Ammonium Molybdate 1.0g/kg seed+ slacked lime@25Kg Ca(OH 2 /ha,(T4-RDF+ ZnSO4@25 kg/ha+ slacked lime@25Kg Ca(OH 2 /ha +Rhizobium+PSB (@Each 5g/kg seed +Ammonium Molybdate 1.0g/kg seed,(T5-50%RDF+ ZnSO4@25 kg/ha +FYM 2.5 t/ha+ slacked lime@25Kg Ca(OH 2 /ha + Rhizobium+PSB (@Each 5g/kg seed + Ammonium Molybdate 1.0g/kg seed + Mulching and(T6-50% RDF + ZnSO4@25 kg/ha+ slacked lime@25 Kg Ca(OH 2 + Vermicompost 1.5t/ha + Rhizobium + *PSB (@Each 5g/kg seed + Ammonium Molybdate1.0g/kg seed + Mulching. Variety JS 95-60 was used under experimentation which was conducted in clay loam soil during kharif seasons of 2010, 2011 and 2012 at ZARS Khargone (M.P The effect of lime based integrated nutrient management and mulching on nodulation, its dry weight, nutrient contents in straw & seed at maturity and grain yield(kg/ha were found to increase significantly and beneficial due to the application of 50% RDF + ZnSO4@25 kg/ha+ slacked lime@25Kg Ca(OH 2 /ha + V.C. 1.5t/ha + B.F.+ A.M. + Mulching(T6 followed by treatment T4 and T5 ( Table 1 over other treatments.

  15. Effects of mulching methods on soil water dynamics and corn yield of rain-fed cropland in the semiarid area of China

    OpenAIRE

    SONG Shang-You; Wang, Hong-Li; ZHANG Xu-Cheng

    2011-01-01

    Aims A new drought-resistance farming technology of double ridges and furrows mulched with plastic film and furrow planting (PMF) is widely applied on rain-fed agriculture in the middle and eastern part of Gansu Province, China, to increase crop yield and water use efficiency. However, its impacts on seasonal and annual soil water dynamics are not well understood. Our objectives were to (a) investigate seasonal and annual changes in soil water content, corn yield and water use efficiency of d...

  16. Evaluating the Effects of Mulch and Irrigation Amount on Soil Water Distribution and Root Zone Water Balance Using HYDRUS-2D

    Directory of Open Access Journals (Sweden)

    Ming Han

    2015-05-01

    Full Text Available Water scarcity is the most critical constraint for sustainable cotton production in Xinjiang Province, northwest China. Drip irrigation under mulch is a major water-saving irrigation method that has been widely practiced for cotton production in Xinjiang. The performance of such an irrigation system should be evaluated for proper design and management. Therefore, a field experiment and a simulation study were conducted to (1 determine a modeling approach that can be applied to manage drip irrigation under mulch for cotton production in this region; and (2 examine the effects of irrigation amount and mulch on soil water distribution and root zone water balance components. In the experiment, four irrigation treatments were used: T1, 166.5 m3; T2, 140.4 m3; T3, 115.4 m3; and T4: 102.3 m3. The HYDRUS-2D model was calibrated, validated, and applied with the data obtained in this experiment. Soil water balance in the 0–70 cm soil profile was simulated. Results indicate that the observed soil water content and the simulated results obtained with HYDRUS-2D are in good agreement. The radius of the wetting pattern, root water uptake, and evaporation decreased as the amount of irrigation was reduced from T1 to T4, while a lot of stored soil water in the root zone was utilized and a huge amount of water was recharged from the layer below 70 cm to compensate for the decrease in irrigation amount. Mulch significantly reduced evaporation by 11.7 mm and increased root water uptake by 11.2 mm. Our simulation study suggests that this model can be applied to provide assistance in designing drip irrigation systems and developing irrigation strategies.

  17. Selectively reflective transparent sheets

    Science.gov (United States)

    Waché, Rémi; Florescu, Marian; Sweeney, Stephen J.; Clowes, Steven K.

    2015-08-01

    We investigate the possibility to selectively reflect certain wavelengths while maintaining the optical properties on other spectral ranges. This is of particular interest for transparent materials, which for specific applications may require high reflectivity at pre-determined frequencies. Although there exist currently techniques such as coatings to produce selective reflection, this work focuses on new approaches for mass production of polyethylene sheets which incorporate either additives or surface patterning for selective reflection between 8 to 13 μ m. Typical additives used to produce a greenhouse effect in plastics include particles such as clays, silica or hydroxide materials. However, the absorption of thermal radiation is less efficient than the decrease of emissivity as it can be compared with the inclusion of Lambertian materials. Photonic band gap engineering by the periodic structuring of metamaterials is known in nature for producing the vivid bright colors in certain organisms via strong wavelength-selective reflection. Research to artificially engineer such structures has mainly focused on wavelengths in the visible and near infrared. However few studies to date have been carried out to investigate the properties of metastructures in the mid infrared range even though the patterning of microstructure is easier to achieve. We present preliminary results on the diffuse reflectivity using FDTD simulations and analyze the technical feasibility of these approaches.

  18. Products Based on Bio-Resourced Materials for Agriculture. Radiation Processed Biodegradable Polymers, Plant Growth Promoters and Superabsorbent Polymers. Chapter 9

    International Nuclear Information System (INIS)

    Radiation-processed natural polymers and their derivatives, namely starch, alginate, chitosan and carboxymethyl cellulose (CMC) were explored for different agricultural applications such as biodegradable mulch films, super adsorbent polymers (SAPs), and plant growth promoters (PGPs). It was observed that gamma radiation-processed starch can lead to a better processability of starch/synthetic polymer alloys, and can offer tuneable biodegradability (as low as one month) with acceptable physico-mechanical properties. Acrylic acid/CMC-based SAP was prepared using 60Co gamma radiation, for soil conditioning. The equilibrium degree of swelling (EDS) of the acrylic acid/CMC SAP was found to be 460 g/g. The field trial of the SAP was conducted on sorghum. It was found that, with the use of 20 kg/ha of SAP, the crop yield can be increased by almost 18.5% whereas the increase in plant height was 8.5%. A new super adsorbent polymer with a much higher water uptake capacity was also developed by adding a small fraction of carrageenan to neutralized acrylic acid (AA). This SAP had EDS of 800 g/g, with the addition of only 1% carrageenan. Experiments to check the soil conditioning efficacy of AA/carrageenan SAP are in progress. Oligomers of chitosan and alginates were prepared by gamma irradiation and were tried as plant growth promoters in wheat (Triticum aestivum), mung bean (Vigna radiata), linseed (Linum usitatissimum), mentha (Mentha arvensis), and lemon grass. The results suggest that these oligomers have a significant impact on the grain and oil yield. Large scale field trials on Mentha arvensis in collaboration with an industry are in progress, and efforts are going on to formulate a policy framework for the use of oligosaccharides as plant growth promoters. (author)

  19. 双季稻田马铃薯不同覆盖栽培对土壤酶活性的影响%Soil enzyme activity in spring potato fields under different mulching practices in double rice cropping area

    Institute of Scientific and Technical Information of China (English)

    林叶春; 曾昭海; 唐海明; 肖小平; 汤文光; 杨光立; 胡跃高

    2011-01-01

    An experiment was designed to explore the effects of different surface mulching practices on soil β-glucosidase, arylamidase, alkalinephosphatase, arylsulfatase and dehydrogenase activities in spring potato fields in double rice cropping areas. Surface mulching practices included zero mulching (CK), rice straw mulching, non-woven fabric mulching, rice straw plus non-woven fabric mulching, black plastic film mulching, and rice straw plus black plastic film mulching. The results indicated that surface mulching significantly affected soil enzyme activity. Compared with CK, the activities of alkaline phosphatase, arylsulfatase and dehydrogenase significantly increased (P<0.05) respectively by 17.55%, 24.77% and 87.2% under rice straw mulching. Arylamidase and dehydrogenase activities increased significantly (P<0.05) by 8.03% and 71.05%, respectively under rice straw plus non-woven fabric mulching. Black plastic film mulching also significant increased (P<0.05) the activities of β-glucosidase, alkaline phosphatase, arylsulfatase and dehydrogenase by 23.44%, 22.70%, 37.43% and 146.30%, respectively. Similarly, rice straw plus black plastic film mulching significantly improved (P<0.05) the activities of β-glucosidase, arylamidase, alkaline phosphatase, arylsulfatase and dehydrogenase by 34.76%, 19.31%, 19.03%, 51.98% and 125.62%, respectively. In conclusion therefore, the activities of soil enzymes related to soil nutrient cycling were significantly enhanced by rice straw plus black plastic film mulching, which in turn enhanced soil fertility and quality.%为探讨双季稻区春马铃薯不同覆盖模式下稻田土壤酶活性的变化情况,在大田条件下,以露地处理为对照,设置稻草、无纺布、稻草+无纺布、黑膜、稻草+黑膜5种覆盖处理.结果表明:地表覆盖显著影响土壤酶活性.其中,稻草覆盖显著(P<0.05)提高碱性磷酸酶、芳基硫酸酯酶和脱氢酶

  20. Effects of soil moisture on cotton root length density and yield under drip irrigation with plastic mulch in Aksu Oasis farmland

    Institute of Scientific and Technical Information of China (English)

    Yilihamu; Yimamu

    2010-01-01

    Effects of soil moisture on cotton root length density (total root length per unit soil volume) and yield under drip irrigation with plastic mulch were studied through field experiments. The results indicate that spatial distributions of root length density of cotton under various water treatments were basically similar. Horizontally, both root length densities of cotton in wide and narrow rows were similar, and higher than that between mulches. Vertically, root length density of cotton decreased with increasing soil depth. The distribution of root length density is different under different irrigation treatments. In conditions of over-irrigation, the root length density of cotton between mulches would increase. However, it would decrease in both the wide rows and narrow rows. The mean root length density of cotton increased with increasing irrigation water. Water stress caused the root length density to increase in lower soil layers. There is a significant correlation between root length density and yields of cotton at the flower-boll and wadding stages. The regression between irrigation amount and yield of cotton can be expressed as y = -0.0026x2+18.015x-24845 (R2 = 0.959). It showed that the irrigation volume of 3,464.4 m3/hm2 led to op-timal root length density. The yield of cotton was 6,360 .8 kg/hm2 under that amount of irrigation.

  1. Effects of soil moisture on cotton root length density and yield under drip irrigation with plastic mulch in Aksu Oasis farmland

    Institute of Scientific and Technical Information of China (English)

    ChengYi ZHAO; YingYu YAN; Yilihamu Yimamu; JuYan LI; ZhiMin ZHAO; LaoSheng WU

    2010-01-01

    Effects of soil moisture on cotton root length density(total root length per unit soil volume)and yield under drip irrigation with plastic mulch were studied through field experiments.The results indicate that spatial distributions of root length density of cotton under various water treatments were basically similar.Horizontally,both root length densities of cotton in wide and narrow rows were similar,and higher than that between mulches.Vertically,root length density of cotton decreased with increasing soil depth.The distribution of root length density is different under different irrigation treatments.In conditions of over-irrigation,the root length density of cotton between mulches would increase.However,it would decrease in both the wide rows and narrow rows.The mean root length density of cotton increased with increasing irrigation water.Water stress caused the root length density to increase in lower soil layers.There is a significant correlation between root length density and yields of cotton at the flower-boll and wadding stages.The regression between irrigation amount and yield of cotton can be expressed as y=-0.0026x2+18.015x-24845(R2=0.959).It showed that the irrigation volume of 3,464.4m3/hm2 led to optimal root length density.The yield of cotton was 6,360.8kg/hm2 under that amount of irrigation.

  2. State Fact Sheets on COPD

    Science.gov (United States)

    ... About CDC.gov . COPD Homepage Data and Statistics Fact Sheets Publications Resources COPD en Español Related Links Air Pollution & Respiratory Health Air Quality, Fires, and Volcanic Eruptions ...

  3. Measurements and Characterization (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2011-06-01

    Capabilities fact sheet for the National Center for Photovoltaics: Measurements and Characterization that includes scope, core competencies and capabilities, and contact/web information for Analytical Microscopy, Electro-Optical Characterization, Surface Analysis, and Cell and Module Performance.

  4. Sociobiology of biodegradation and the role of predatory protozoa in biodegrading communities

    Indian Academy of Sciences (India)

    Tejashree Modak; Shalmali Pradhan; Milind Watve

    2007-06-01

    Predatory protozoa are known to enhance biodegradation by bacteria in a variety of systems including rumen. This is apparently counterintuitive since many protozoa do not themselves produce extracellular degradative enzymes and prey upon bacterial degraders. We propose a mechanism of protozoal enhancement of bacterial biodegradation based on the sociobiology of biodegradation. Since extracellular enzyme production by degraders involves a cost to the bacterial cell, cheaters that do not make the enzyme will have a selective advantage. In the presence of cheaters, degraders that physically attach to water-insoluble substrate will have a selective advantage over free-floating degraders. On the other hand, cheaters will benefit by being free floaters since they consume the solubilized products of extracellular enzymes. Predatory ciliated protozoa are more likely to consume free-floating cheaters. Thus, due to protozoan predation a control is exerted on the cheater population. We illustrate the dynamics of such a system with the help of a computer simulation model. Available data on rumen and other biodegradation systems involving protozoa are compatible with the assumptions and predictions of the model.

  5. Biodegradable and semi-biodegradable composite hydrogels as bone substitutes: morphology and mechanical characterization.

    Science.gov (United States)

    Sanginario, V; Ginebra, M P; Tanner, K E; Planell, J A; Ambrosio, L

    2006-05-01

    Biodegradable and semi-biodegradable composite hydrogels are proposed as bone substitutes. They consist of an hydrophilic biodegradable polymer (HYAFF 11) as matrix and two ceramic powders (alpha-TCP and HA) as reinforcement. Both components of these composites have been of great interest in biomedical applications due to their excellent biocompatibility and tissue interactions, however they have never been investigated as bone substitute composites. Morphological and mechanical analysis have shown that the two fillers behave in a very different way. In the HYAFF 11/alpha-TCP composite, alpha-TCP is able to hydrolyze in contact with water while in the HYAFF 11 matrix. As a result, the composite sets and hardens, and entangled CDHA crystals are formed in the hydrogel phase and increases in the mechanical properties are obtained. In the HYAFF11/HA composite the ceramic reinforcement acts as inert phase leading to lower mechanical properties. Both mechanical properties and microstructure analysis have demonstrated the possibility to design hydrophilic biodegradable composite structures for bone tissue substitution applications. PMID:16688585

  6. Seeing graphene-based sheets

    OpenAIRE

    Jaemyung Kim; Franklin Kim; Jiaxing Huang

    2010-01-01

    Graphene-based sheets such as graphene, graphene oxide and reduced graphene oxide have stimulated great interest due to their promising electronic, mechanical and thermal properties. Microscopy imaging is indispensable for characterizing these single atomic layers, and oftentimes is the first measure of sample quality. This review provides an overview of current imaging techniques for graphene-based sheets and highlights a recently developed fluorescence quenching microscopy technique that al...

  7. Financial intermediary balance sheet management

    OpenAIRE

    Adrian,Tobias; Shin, Hyun Song

    2011-01-01

    Conventional discussions of balance sheet management by nonfinancial firms take the set of positive net present value (NPV) projects as given, which in turn determines the size of the assets of the firm. The focus is on the composition of equity and debt in funding such assets. In contrast, the balance sheet management of financial intermediaries reveals that it is equity that behaves like the predetermined variable, and the asset size of the bank or financial intermediary is determined by th...

  8. Energy information sheets, July 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the public. The Energy Information Sheets was developed to provide general information on various aspects of fuel production, prices, consumption, and capability. Additional information on related subject matter can be found in other Energy Information Administration (EIA) publications as referenced at the end of each sheet.

  9. Energy information sheets, September 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    The National Energy Information Center (NEIC), as part of its mission, provides energy information and referral assistance to Federal, State, and local governments, the academic community, business and industrial organizations, and the public. The Energy Information Sheets was developed to provide general information on various aspects of fuel production, prices, consumption, and capability. Additional information on related subject matter can be found in other Energy Information Administration (EIA) publications as referenced at the end of each sheet.

  10. Development of biodegradable fungicide by radiation

    International Nuclear Information System (INIS)

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified. Microbial pesticide were manufactured in combination of various additives. Antiphytopathogenic effects were proven by pot experiment and It was promising to prevent pepper, Chinese cabbage and radish from anthrax, phytophthora and root rot

  11. Development of biodegradable fungicide by radiation

    International Nuclear Information System (INIS)

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Sixteen antifungal microbes were isolated and 4 antifungal activity enhanced mutants were induced by using radiation. P. lentimorbus WJ5a17 had 41% higher antifungal activity than the wild type. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified

  12. Lipase biocatalysis for useful biodegradable products

    Energy Technology Data Exchange (ETDEWEB)

    Linko, Y.Y.; Wang, Zhuo Lin; Uosukainen, E.; Seppaelae, J. [Helsinki Univ. of Technology, Espoo (Finland); Laemsae, M. [Raisio Group Oil Milling Industry, Raisio (Finland)

    1996-12-31

    It was shown that lipases can be used as biocatalysts in the production of useful biodegradable compounds such as 1-butyl oleate by direct esterification of butanol and oleic acid to decrease viscosity of biodiesel in winter use. By enzymic transesterification, a mixture of 2-ethyl-1-hexyl esters from rapeseed oil fatty acids can be obtained in good yields for use as a solvent, and of trimethylolpropane esters for use as a lubricant. Finally, it was demonstrated that polyesters with a mass average molar mass in excess of 75,000 g mol{sup -}1 can be obtained by esterification or transesterification by using lipase as biocatalyst. (author) (3 refs.)

  13. Development of biodegradable fungicide by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youngkeun; Kim, Dongsub

    2012-03-15

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified. Microbial pesticide were manufactured in combination of various additives. Antiphytopathogenic effects were proven by field test and it was promising to prevent Chinese cabbage and radish from phytophthora and root rot.

  14. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Martins

    2012-09-01

    Full Text Available Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

  15. Biodegradable Poly(Lactic Acid/Multiwalled Carbon Nanotube Nanocomposite Fabrication Using Casting And Hot Press Techniques

    Directory of Open Access Journals (Sweden)

    Park S.G.

    2015-06-01

    Full Text Available Biodegradable advanced polymer composites have recently received a large amount of attention. The present study aimed to design poly(lactic acid multiwalled carbon nanotube nanocomposites (PLA/MWCNTs using a simple fabrication technique. A PLA sheet was first dissolved in dichloromethane, and MWCNTs were subsequently added at various concentrations (0.5, 1.5 and 5% while applying shear strain stirring to achieve dispersion of carbon nanotubes (CNTs. These solutions were then molded and a hot press was used to generate sheets free of voids with entrapped solvent. The prepared samples were characterized using field emission scanning electron microscopy (FE-SEM, x-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, and thermogravimetric analysis (TGA. Our data showed composite samples free of defects and voids, indicating that the hot press is capable of generating sufficiently compact polymer matrices. Additionally, TGA and FTIR showed significant bonding interactions between the PLA matrix and the nano-fillers. Collectively, our results suggest that incorporation of CNTs as nano-fillers into biodegradable polymers may have multiple applications in many different sectors.

  16. Hydrocarbons biodegradation in unsaturated porous medium; Biodegradation des hydrocarbures en milieu poreux insature

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, C

    2007-12-15

    Biological processes are expected to play an important role in the degradation of petroleum hydrocarbons in contaminated soils. However, factors influencing the kinetics of biodegradation are still not well known, especially in the unsaturated zone. To address these biodegradation questions in the unsaturated zone an innovative experimental set up based on a physical column model was developed. This experimental set up appeared to be an excellent tool for elaboration of a structured porous medium, with well defined porous network and adjusted water/oil saturations. Homogeneous repartition of both liquid phases (i.e., aqueous and non aqueous) in the soil pores, which also contain air, was achieved using ceramic membranes placed at the bottom of the soil column. Reproducible interfaces (and connectivity) are developed between gas, and both non mobile water and NAPL phases, depending on the above-defined characteristics of the porous media and on the partial saturations of these three phases (NAPL, water and gas). A respirometric apparatus was coupled to the column. Such experimental set up have been validated with hexadecane in dilution in an HMN phase. This approach allowed detailed information concerning n-hexadecane biodegradation, in aerobic condition, through the profile of the oxygen consumption rate. We have taken benefit of this technique, varying experimental conditions, to determine the main parameters influencing the biodegradation kinetics and compositional evolution of hydrocarbons, under steady state unsaturated conditions and with respect to aerobic metabolism. Impacts of the nitrogen quantity and of three different grain sizes have been examined. Biodegradation of petroleum cut, as diesel cut and middle distillate without aromatic fraction, were, also studied. (author)

  17. Compared in vivo toxicity in mice of lung delivered biodegradable and non-biodegradable nanoparticles.

    Science.gov (United States)

    Aragao-Santiago, Letícia; Hillaireau, Hervé; Grabowski, Nadège; Mura, Simona; Nascimento, Thais L; Dufort, Sandrine; Coll, Jean-Luc; Tsapis, Nicolas; Fattal, Elias

    2016-04-01

    To design nanoparticle (NP)-based drug delivery systems for pulmonary administration, biodegradable materials are considered safe, but their potential toxicity is poorly explored. We here explore the lung toxicity in mice of biodegradable nanoparticles (NPs) and compare it to the toxicity of non-biodegradable ones. NP formulations of poly(d,l-lactide-co-glycolide) (PLGA) coated with chitosan (CS), poloxamer 188 (PF68) or poly(vinyl alcohol) (PVA), which renders 200 nm NPs of positive, negative or neutral surface charge respectively, were analyzed for their biodistribution by in vivo fluorescence imaging and their inflammatory potential after single lung nebulization in mice. After exposure, analysis of bronchoalveolar lavage (BAL) cell population, protein secretion and cytokine release as well as lung histology were carried out. The inflammatory response was compared to the one induced by non-biodegradable counterparts, namely, TiO2 of rutile and anatase crystal form and polystyrene (PS). PLGA NPs were mostly present in mice lungs, with little passage to other organs. An increase in neutrophil recruitment was observed in mice exposed to PS NPs 24 h after nebulization, which declined at 48 h. This result was supported by an increase in interleukin (IL)-6 and tumor necrosis factor α (TNFα) in BAL supernatant at 24 h. TiO2 anatase NPs were still present in lung cells 48 h after nebulization and induced the expression of pro-inflammatory cytokines and the recruitment of polymorphonuclear cells to BAL. In contrast, regardless of their surface charge, PLGA NPs did not induce significant changes in the inflammation markers analyzed. In conclusion, these results point out to a safe use of PLGA NPs regardless of their surface coating compared to non-biodegradable ones. PMID:26573338

  18. Biodegradation of clofibric acid and identification of its metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, R. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); ESTS-IPS, Escola Superior de Tecnologia de Setubal do Instituto Politecnico de Setubal, Rua Vale de Chaves, Campus do IPS, Estefanilha, 2910-761 Setubal (Portugal); Oehmen, A. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Carvalho, G. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Instituto de Biologia Experimental e Tecnologica (IBET), Av. da Republica (EAN), 2784-505 Oeiras (Portugal); Noronha, J.P. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Reis, M.A.M., E-mail: amr@fct.unl.pt [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2012-11-30

    Graphical abstract: Metabolites produced during clofibric acid biodegradation. Highlights: Black-Right-Pointing-Pointer Clofibric acid is biodegradable. Black-Right-Pointing-Pointer Mainly heterotrophic bacteria degraded the clofibric acid. Black-Right-Pointing-Pointer Metabolites of clofibric acid biodegradation were identified. Black-Right-Pointing-Pointer The metabolic pathway of clofibric acid biodegradation is proposed. - Abstract: Clofibric acid (CLF) is the pharmaceutically active metabolite of lipid regulators clofibrate, etofibrate and etofyllinclofibrate, and it is considered both environmentally persistent and refractory. This work studied the biotransformation of CLF in aerobic sequencing batch reactors (SBRs) with mixed microbial cultures, monitoring the efficiency of biotransformation of CLF and the production of metabolites. The maximum removal achieved was 51% biodegradation (initial CLF concentration = 2 mg L{sup -1}), where adsorption and abiotic removal mechanisms were shown to be negligible, showing that CLF is indeed biodegradable. Tests showed that the observed CLF biodegradation was mainly carried out by heterotrophic bacteria. Three main metabolites were identified, including {alpha}-hydroxyisobutyric acid, lactic acid and 4-chlorophenol. The latter is known to exhibit higher toxicity than the parent compound, but it did not accumulate in the SBRs. {alpha}-Hydroxyisobutyric acid and lactic acid accumulated for a period, where nitrite accumulation may have been responsible for inhibiting their degradation. A metabolic pathway for the biodegradation of CLF is proposed in this study.

  19. Biodegradable elastomers for biomedical applications and regenerative medicine

    NARCIS (Netherlands)

    Bat, Erhan; Zhang, Zheng; Feijen, Jan; Grijpma, Dirk W.; Poot, Andre A.

    2014-01-01

    Synthetic biodegradable polymers are of great value for the preparation of implants that are required to reside only temporarily in the body. The use of biodegradable polymers obviates the need for a second surgery to remove the implant, which is the case when a nondegradable implant is used. After

  20. Biodegradation of Phosphonomycin by Rhizobium huakuii PMY1

    OpenAIRE

    McGrath, John W.; Hammerschmidt, Friedrich; Quinn, John P.

    1998-01-01

    The biodegradation by Rhizobium huakuii PMY1 of up to 10 mM phosphonomycin as a carbon, energy, and phosphorus source with accompanying Pi release is described. This biodegradation represents a further mechanism of resistance to this antibiotic and a novel, phosphate-deregulated route for organophosphonate metabolism by Rhizobium spp.

  1. Evaluation of evapotranspiration and deep percolation under mulched drip irrigation in an oasis of Tarim basin, China

    Science.gov (United States)

    Li, Xianwen; Jin, Menggui; Zhou, Nianqing; Huang, Jinou; Jiang, Simin; Telesphore, Habiyakare

    2016-07-01

    Mulched drip irrigation for cotton field is an effective measure for the utilization of saline water, and the regulation of soil water and salt. However, the reasonable methods for quantifying actual evapotranspiration (ET) and deep percolation of recharge to groundwater are still not very well understood, which restricts the accurate regulation of soil water and salt for cotton growth in oasis. In this paper, a set of experiments of mulched drip irrigation with brackish water were conducted in a typical arid region of Tarim basin in southern Xinjiang, China. The irrigation events were recorded, and ET and fluctuations of groundwater table were carefully measured for two consecutive irrigation periods of flowering and bolling stages. A group of upscaling conversion methods were used to quantify the ET, in which canopy structure was considered to estimate the transpiration from leaf scale to a unit of field scale. The groundwater table had a significant response to the irrigation events, thus the deep percolation was estimated using water-table fluctuation method (WTF). Results showed that during the two irrigation events of flowering and bolling stages, the total ET was 31.1 mm with the soil surface evaporation of only 0.4 mm. The total percolation of recharge to groundwater was 48.2 mm which contributed to the groundwater run-off of 22.1 mm. Transpiration of 30.7 mm accounted for 98.6% of the total ET of 31.1 mm and 34.3% of the irrigation water of 90.6 mm. Compared with transpiration, the deep percolation accounted for 53.2% of irrigation water, indicating a serious excessive irrigation that recharged to groundwater. Soil salt budget showed that the salt leached into groundwater was 1.56 times of the input from brackish irrigation water and fertilization during the two irrigation periods. Even for the irrigation practice with brackish water, the accumulated salt of soil profile could also be leached out under large amount of irrigation water (e.g. 90.6 mm for the

  2. Evaluation of Artificial Intelligence Based Models for Chemical Biodegradability Prediction

    Directory of Open Access Journals (Sweden)

    Aleksandar Sabljic

    2004-12-01

    Full Text Available This study presents a review of biodegradability modeling efforts including a detailed assessment of two models developed using an artificial intelligence based methodology. Validation results for these models using an independent, quality reviewed database, demonstrate that the models perform well when compared to another commonly used biodegradability model, against the same data. The ability of models induced by an artificial intelligence methodology to accommodate complex interactions in detailed systems, and the demonstrated reliability of the approach evaluated by this study, indicate that the methodology may have application in broadening the scope of biodegradability models. Given adequate data for biodegradability of chemicals under environmental conditions, this may allow for the development of future models that include such things as surface interface impacts on biodegradability for example.

  3. Experimental studies of biodegradation of asphalt by microorganisms

    International Nuclear Information System (INIS)

    On the geological disposal system of the radioactive wastes, the activities of the microorganisms that could degrade the asphalt might be significant for the assessment of the system performance. As the main effects of the biodegradation of the asphalt, the fluctuation of leaching behavior of the nuclides included in asphalt waste has been indicated. In this study, the asphalt biodegradation test was carried out. The microorganism of which asphalt degradation ability was comparatively higher under aerobic condition and anaerobic condition was used. The asphalt biodegradation rate was calculated and it was evaluated whether the asphalt biodegradation in this system could occur. The results show that the asphalt biodegradation rate under anaerobic and high alkali condition will be 300 times lower than under aerobic and neutral pH. (author)

  4. Critical evaluation of biodegradable polymers used in nanodrugs

    Directory of Open Access Journals (Sweden)

    Marin E

    2013-08-01

    Full Text Available Edgar Marin,1–3 Maria Isabel Briceño,2 Catherina Caballero-George11Unit of Pharmacology, Center of Biodiversity and Drug Discovery, Institute of Scientific Research and High Technology Services, 2Nano Dispersions Technology, Panama, Republic of Panama; 3Department of Biotechnology, Archaria Nagarjuna University, Guntur, IndiaAbstract: Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, flexibility, and minimal side effects. Applications of these materials include creation of skin, blood vessels, cartilage scaffolds, and nanosystems for drug delivery. These biodegradable polymeric nanoparticles enhance properties such as bioavailability and stability, and provide controlled release of bioactive compounds. This review evaluates the classification, synthesis, degradation mechanisms, and biological applications of the biodegradable polymers currently being studied as drug delivery carriers. In addition, the use of nanosystems to solve current drug delivery problems are reviewed.Keywords: biodegradable polymers, nanoparticles, drug delivery, cellular uptake, biomedical applications

  5. Polymeric Biodegradable Stent Insertion in the Esophagus

    Directory of Open Access Journals (Sweden)

    Kai Yang

    2016-04-01

    Full Text Available Esophageal stent insertion has been used as a well-accepted and effective alternative to manage and improve the quality of life for patients diagnosed with esophageal diseases and disorders. Current stents are either permanent or temporary and are fabricated from either metal or plastic. The partially covered self-expanding metal stent (SEMS has a firm anchoring effect and prevent stent migration, however, the hyperplastic tissue reaction cause stent restenosis and make it difficult to remove. A fully covered SEMS and self-expanding plastic stent (SEPS reduced reactive hyperplasia but has a high migration rate. The main advantage that polymeric biodegradable stents (BDSs have over metal or plastic stents is that removal is not require and reduce the need for repeated stent insertion. But the slightly lower radial force of BDS may be its main shortcoming and a post-implant problem. Thus, strengthening support of BDS is a content of the research in the future. BDSs are often temporarily effective in esophageal stricture to relieve dysphagia. In the future, it can be expect that biodegradable drug-eluting stents (DES will be available to treat benign esophageal stricture, perforations or leaks with additional use as palliative modalities for treating malignant esophageal stricture, as the bridge to surgery or to maintain luminal patency during neoadjuvant chemoradiation.

  6. Biodegradation of cresol isomers in anoxic aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Smolenski, W.J.; Suflita, J.M.

    1987-04-01

    The biodegradation of o-, m-, and p-cresol was examined in material obtained from a shallow anaerobic alluvial sand aquifer. The cresol isomers wer preferentially metabolized, with p-cresol being the most easily degraded. m-Cresol was more persistent than the para-isomer, and o-cresol persisted for over 90 days. Biodegradations of cresol isomers was favored under sulfate-reducing conditions (SRC) compared with that under methanogenic conditions (MC). Slurries that were acclimated to p-cresol metabolism transformed this substrate at 18 and 330 nmol/h per g (dry weight) for MC and SRC, respectively. Inhibition of electron flow to sulfate reduction with 2.0 mM molybdate reduced p-cresol metabolism in incubations containing sulfate. When methanogenesis was blocked with 5 mM bromoethanesulfonic acid in incubations lacking sulfate, p-cresol catabolism was retarded. Under SRC 3.4 mol of sulfate was consumed per mol of p-cresol metabolized. The addition of sulfate to methanogenic incubations stimulated p-cresol degradation. Simultaneous adaptation studies in combination with spectrophotometric and chromatographic analysis of metabolites indicated that p-cresol was oxidized under SRC to p-hydroxybenzoate via the corresponding alcohol and aldehyde. This series of reactions was inhibited under sulfate-limited or aerobic conditions. Therefore, the primary catabolic event for p-cresol decomposition under SRC appears to involve the hydroxylation of the aryl methyl group.

  7. Optimization of low ring polycylic aromatic biodegradation

    Science.gov (United States)

    Othman, N.; Abdul-Talib, S.; Tay, C. C.

    2016-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are recalcitrance and persistence that finally turn into problematic environmental contaminants. Microbial degradation is considered to be the primary mechanism of PAHs removal from the environment due to its organic criteria. This study is carried out to optimize degradation process of low ring PAHs. Bacteria used in this study was isolated from sludge collected from Kolej Mawar, Universiti Teknologi MARA, Shah Alam, Selangor. Working condition namely, substrate concentration, bacteria concentration, pH and temperature were optimized. PAHs in the liquid sample was extracted by using solid phase microextractio equipped with a 7 µm polydimethylsiloxane (PDMS) SPME fibr. Removal of PAHs were assessed by measuring PAHs concentration using GC-FID. Results from the optimization study of biodegradation indicated that maximum rate of PAHs removal occurred at 100 mgL-1 of PAHs, 10% bacteria concentration, pH 7.0 and 30°C. These working condition had proved the effectiveness of using bacteria in biodegradation process of PAHs.

  8. Monitoring Biodegradation of Magnesium Implants with Sensors

    Science.gov (United States)

    Zhao, Daoli; Wang, Tingting; Guo, Xuefei; Kuhlmann, Julia; Doepke, Amos; Dong, Zhongyun; Shanov, Vesselin N.; Heineman, William R.

    2016-04-01

    Magnesium and its alloys exhibit properties such as high strength, light weight, and in vivo corrosion that make them promising candidates for the development of biodegradable metallic implant materials for bone repair, stents and other medical applications. Sensors have been used to monitor the corrosion of magnesium and its alloys by measuring the concentrations of the following corrosion products: magnesium ions, hydroxyl ions and hydrogen gas. The corrosion characterization system with home-made capillary pH and Mg2+ microsensors has been developed for real-time detection of magnesium corrosion in vitro. A hydrogen gas sensor was used to monitor the corrosion of magnesium by measuring the concentration of the hydrogen gas reaction product in vivo. The high permeability of hydrogen through skin allows transdermal monitoring of the biodegradation of a magnesium alloy implanted beneath the skin by detecting hydrogen gas at the skin surface. The sensor was used to map hydrogen concentration in the vicinity of an implanted magnesium alloy.

  9. Immunological Response to Biodegradable Magnesium Implants

    Science.gov (United States)

    Pichler, Karin; Fischerauer, Stefan; Ferlic, Peter; Martinelli, Elisabeth; Brezinsek, Hans-Peter; Uggowitzer, Peter J.; Löffler, Jörg F.; Weinberg, Annelie-Martina

    2014-04-01

    The use of biodegradable magnesium implants in pediatric trauma surgery would render surgical interventions for implant removal after tissue healing unnecessary, thereby preventing stress to the children and reducing therapy costs. In this study, we report on the immunological response to biodegradable magnesium implants—as an important aspect in evaluating biocompatibility—tested in a growing rat model. The focus of this study was to investigate the response of the innate immune system to either fast or slow degrading magnesium pins, which were implanted into the femoral bones of 5-week-old rats. The main alloying element of the fast-degrading alloy (ZX50) was Zn, while it was Y in the slow-degrading implant (WZ21). Our results demonstrate that degrading magnesium implants beneficially influence the immune system, especially in the first postoperative weeks but also during tissue healing and early bone remodeling. However, rodents with WZ21 pins showed a slightly decreased phagocytic ability during bone remodeling when the degradation rate reached its maximum. This may be due to the high release rate of the rare earth-element yttrium, which is potentially toxic. From our results we conclude that magnesium implants have a beneficial effect on the innate immune system but that there are some concerns regarding the use of yttrium-alloyed magnesium implants, especially in pediatric patients.

  10. Modification of Biodegradable Polyesters Using Electron Beam

    International Nuclear Information System (INIS)

    Poly(4-Hydroxybutyrate) P4HB, Poly(butylene succinate-co-adipate) PBSA and Poly(ε-caprolactone) PCL were electron beam (EB)-irradiated. Poly(4-Hydroxybutyrate) was irradiated without any polyfunctional monomers (PFM). While PBSA and PCL were irradiated in the presence of polyfunctional monomers such as Trimethallyl isocyanurate (TMAIC), Polyethyleneglycol dimethacrylate (2G, 4G), Trimethylolpropane trimethacrylate (TMPT) and Tetramethylolmethane tetraacrylate (A-TMMT) at ambient temperature. Aim of the study is to improve the properties of biodegradable polyester. It was pointed out that crosslinking yield of P4HB (6.39% gel) was formed at dose of 90 kGy irradiated in vacuum conditions. Radiation degradation promoted, when P4HB was irradiated in air. The optimum crosslinking yield of PCL and PBSA respectively, were formed in the presence of 1% TMAIC at dose of 50 kGy. The biodegradability of the crosslinked PBSA evaluated by soil burial test is slightly retarded by increasing crosslinking yields. (author)

  11. A REVIEW ON BIODEGRADABLE STARCH BASED FILM

    Directory of Open Access Journals (Sweden)

    Hooman Molavi

    2015-04-01

    Full Text Available In recent years, biodegradable edible films have become very important in research related to food, due to their compatibility with the environment and their use in the food packaging industry. Various sources can be used in the production of biopolymers as biodegradable films that include polysaccharides, proteins and lipids. Among the various polysaccharides, starch due to its low price and its abundance in nature is of significant importance. Several factors affect the properties of starch films; such as the source which starch is obtained from, as well as the ratio of constituents of the starch. Starch films have advantages such as low thickness, flexibility and transparency though; there are some downsides to mention, such as the poor mechanical properties and water vapor permeability. Thus, using starch alone to produce the film will led to restrictions on its use. To improve the mechanical properties of starch films and also increases resistance against humidity, several methods can be used; including the starch modifying techniques such as cross linking of starch and combining starch with other natural polymers. Other methods such as the use of lipid in formulations of films to increase the resistance to moisture are possible, but lipids are susceptible to oxidation. Therefore, new approaches are based on the integration of different biopolymers in food packaging.

  12. Automobile sheet metal part production with incremental sheet forming

    Directory of Open Access Journals (Sweden)

    İsmail DURGUN

    2016-02-01

    Full Text Available Nowadays, effect of global warming is increasing drastically so it leads to increased interest on energy efficiency and sustainable production methods. As a result of adverse conditions, national and international project platforms, OEMs (Original Equipment Manufacturers, SMEs (Small and Mid-size Manufacturers perform many studies or improve existing methodologies in scope of advanced manufacturing techniques. In this study, advanced manufacturing and sustainable production method "Incremental Sheet Metal Forming (ISF" was used for sheet metal forming process. A vehicle fender was manufactured with or without die by using different toolpath strategies and die sets. At the end of the study, Results have been investigated under the influence of method and parameters used.Keywords: Template incremental sheet metal, Metal forming

  13. Guide for waste profile sheets

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-09-15

    This waste profile sheet was prepared to help petroleum industry operators properly classify and handle industrial waste. The profile sheets complied with British Columbia (BC) occupational health and safety regulations. Waste sheets were provided for compressed gases; flammable and combustible materials; oxidizing materials; poisonous materials; toxic materials; biohazardous and infectious materials; corrosive materials; and dangerously reactive materials. The waste information sheets were divided into 4 sections: (1) general information, (2) hazard information, (3) management methods, and (4) transportation. Sheets were provided for absorbents and rags; acids; batteries; carbon-amine; carbon-glycol; flammable and self-heating carbon; metal catalysts; caustic materials; contaminated debris; desiccant materials; drill sump materials; filters; raw gas fluids; frac fluids; hydrotest fluids; incinerator ashes; lubricating oils; PCBs; pigging wax; various sludges; solvent residues; process water; and well workover fluids. Detailed information on the handling, storage and disposal of the wastes was provided, as well as information related to reportable releases, required labels and placards, and documentation related to hazardous waste shipment. tabs., figs.

  14. Uranium mining sites - Thematic sheets

    International Nuclear Information System (INIS)

    A first sheet proposes comments, data and key numbers about uranium extraction in France: general overview of uranium mining sites, status of waste rock and tailings after exploitation, site rehabilitation. The second sheet addresses the sources of exposure to ionizing radiations due to ancient uranium mining sites: discussion on the identification of these sources associated with these sites, properly due to mining activities or to tailings, or due to the transfer of radioactive substances towards water and to the contamination of sediments, description of the practice and assessment of radiological control of mining sites. A third sheet addresses the radiological exposure of public to waste rocks, and the dose assessment according to exposure scenarios: main exposure ways to be considered, studied exposure scenarios (passage on backfilled path and grounds, stay in buildings built on waste rocks, keeping mineralogical samples at home). The fourth sheet addresses research programmes of the IRSN on uranium and radon: epidemiological studies (performed on mine workers; on French and on European cohorts, French and European studies on the risk of lung cancer associated with radon in housing), study of the biological effects of chronic exposures. The last sheet addresses studies and expertises performed by the IRSN on ancient uranium mining sites in France: studies commissioned by public authorities, radioactivity control studies performed by the IRSN about mining sites, participation of the IRSN to actions to promote openness to civil society

  15. Agronomic performance of common bean in straw mulch systems and topdressing nitrogen rates in no-tillage

    Directory of Open Access Journals (Sweden)

    Tatiana Pagan Loeiro da Cunha

    2015-10-01

    Full Text Available ABSTRACTIn no-tillage systems, straw coverage on soil surface is the key to success, and the choice of crops for rotation is crucial to achieve the sustainability and quality that conservation agriculture requires. The objective of this study was to evaluate the agronomic performance of the common bean cultivar IAC Formoso sown in succession to three straw mulch systems (corn alone, corn/Urochloa ruziziensisintercrop and U. ruziziensisalone and topdress nitrogen rates (0; 40; 80; 120 and 160 kg ha-1N, at the four-leaf stage, three years after the implementation of no-tillage. The experiment was arranged in a randomized block split plot design, with three replications. Common bean highest yields were achieved in succession to U. ruziziensisalone and intercropped with corn. The corn/U. ruziziensisintercrop provided both straw and seed production, allowing for quality no-tillage. Topdressed nitrogen influenced the common bean yield when in succession to corn alone, U. ruziziensisalone and corn/U. ruziziensisintercrop in no-tillage.

  16. [Effect of controlled release fertilizer on nitrous oxide emission from paddy field under plastic film mulching cultivation].

    Science.gov (United States)

    Zhang, Yi; Lü, Shi-Hua; Ma, Jing; Xu, Hua; Yuan, Jiang; Dong, Yu-Jiao

    2014-03-01

    A field experiment was conducted to assess the effect of controlled release fertilizer on N2O emission in paddy field under plastic film mulching cultivation (PM) with water-saving irrigation. Results showed that in the rice growing season, cumulative N2O emissions from the plots applied with urea (PM+U) and with controlled release fertilizer (PM+CRF) were (38.2 +/- 4.4) and (21.5 +/- 5.2) mg N x m(-2), respectively. The N2O emission factors were 0.25% and 0.14% in the treatments PM+U and PM+CRF, respectively. The controlled release fertilizer decreased the total N2O emission by 43.6% compared with urea, of which 49.6% was reduced before the drying period. It also reduced the peak of N2O emission by 52.6%. However, it did not affect soil microbial biomass N and soil NH(4+)-N content at any rice growing stage, and grain yield either. No significant correlation was observed between N2O flux and soil Eh or soil temperature at the depth of 5 cm. PMID:24984495

  17. Development of polysaccharide based biodegradable packaging materials suitable for radiation sterilization

    International Nuclear Information System (INIS)

    The biodegradable composites are prepared by melt blending method in Poly-lab Rheomix internal mixer from Thermo Electron. The high-density polyethylene (90 wt%) and maleic anhydride grafted polyethylene (10 wt%) are heat melted at 170 °C under the constant rotors speed (60 rpm). After 3 min, maize starch (Gelose 80) 10 parts per hundred (phr), sepiolite, stearic acid (1 phr), Irganox 1010 (0.2 phr) and Irgafos 168 (0.1 phr) are added and mixed for another 15 min. The sepiolite is varied from 2 to 6 phr in these composites. The PE0, PE2, PE4 and PE6 identification codes are used to represent composites containing 0, 2, 4 and 6 phr of sepiolite respectively. The heat pressed sheets are prepared at 170 οC at 200 bar. These sheet are irradiated under electron beam in air at room temperature using UELV-10-10S linear electron beam irradiator (NIIEFA, Russia) at 10 MeV and 1mA using 1 kGy/pass. The samples are subjected to various doses of electron beam irradiation ranging from 25 to 100 kGy. The structural and morphological analysis of developed composites is characterized by Fourier transform infrared spectrophotometer and scanning electron microscope. The thermal properties are investigated using thermo-gravimetric analyzer and differential scanning calorimeter. The gel content and tensile properties are also measured

  18. Biodegradation of hydrocarbon cuts used for diesel oil formulation

    Energy Technology Data Exchange (ETDEWEB)

    Penet, S.; Marchal, R.; Monot, F. [Departement de Biotechnologie et Chimie de la Biomasse, Institut Francais de Petrole, Rueil-Malmaison (France); Sghir, A. [Genoscope, CNRS UMR 8030, Structure et Evolution des Genomes, Evry (France)

    2004-11-01

    The biodegradability of various types of diesel oil (DO), such as straight-run DO, light-cycle DO, hydrocracking DO, Fischer-Tropsch DO and commercial DO, was investigated in biodegradation tests performed in closed-batch systems using two microflorae. The first microflora was an activated sludge from an urban wastewater treatment plant as commonly used in biodegradability tests of commercial products and the second was a microflora from a hydrocarbon-polluted soil with possible specific capacities for hydrocarbon degradation. Kinetics of CO{sub 2} production and extent of DO biodegradation were obtained by chromatographic procedures. Under optimised conditions, the polluted-soil microflora was found to extensively degrade all the DO types tested, the degradation efficiencies being higher than 88%. For all the DOs tested, the biodegradation capacities of the soil microflora were significantly higher than those of the activated sludge. Using both microflora, the extent of biodegradation was highly dependent upon the type of DO used, especially its hydrocarbon composition. Linear alkanes were completely degraded in each test, whereas identifiable branched alkanes such as farnesane, pristane or phytane were degraded to variable extents. Among the aromatics, substituted mono-aromatics were also variably biodegraded. (orig.)

  19. [Biodegradation Coefficients of Typical Pollutants in the Plain Rivers Network].

    Science.gov (United States)

    Feng, Shuai; Li, Xu-yongl; Deng, Jian-cai

    2016-05-15

    Biodegradation is a significant part of pollutant integrated degradation, the process rate of which is represented by the biodegradation coefficient. To investigate the biodegradation law of typical pollutants in the plain rivers network located in the upstream of the Lake Taihu, experiments were conducted in site in September 2015, one order kinetics model was used to measure the biodegradation coefficients for permanganate index, ammonia, total nitrogen and total phosphorus, and influencing factors of the biodegradation coefficients were also analyzed. The results showed that the biodegradation coefficients for permanganate index, ammonia, total nitrogen and total phosphorus were 0.008 3-0.126 4 d⁻¹, 0.002 1-0.213 8 d⁻¹, 0.002 1-0.090 5 d⁻¹ and 0.011 0- 0.152 8 d⁻¹, respectively. The influencing factors of the biodegradation coefficients for permanganate index were permanganate index and pH; those for ammonia were ammonia concentration and pH; those for total nitrogen were inorganic nitrogen concentration, total dissolved solid concentration and nitrite concentration; and those for total phosphorus were background concentration and pH. The research results were of important guiding significance for pollutants removal and ecological restoration of the plain rivers network located in the unstream of the Lake Taihu. PMID:27506025

  20. Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

    Directory of Open Access Journals (Sweden)

    José Maria Rodrigues da Luz

    Full Text Available Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate.

  1. Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

    Science.gov (United States)

    da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Nunes, Mateus Dias; da Silva, Marliane de Cássia Soares; Kasuya, Maria Catarina Megumi

    2013-01-01

    Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate. PMID:23967057

  2. Ice sheet hydrology - a review

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Peter; Naeslund, Jens-Ove [Dept. of Physical Geography and Quaternary Geology, Stockholm Univ., Stockholm (Sweden); Rodhe, Lars [Geological Survey of Sweden, Uppsala (Sweden)

    2007-03-15

    This report summarizes the theoretical knowledge on water flow in and beneath glaciers and ice sheets and how these theories are applied in models to simulate the hydrology of ice sheets. The purpose is to present the state of knowledge and, perhaps more importantly, identify the gaps in our understanding of ice sheet hydrology. Many general concepts in hydrology and hydraulics are applicable to water flow in glaciers. However, the unique situation of having the liquid phase flowing in conduits of the solid phase of the same material, water, is not a commonly occurring phenomena. This situation means that the heat exchange between the phases and the resulting phase changes also have to be accounted for in the analysis. The fact that the solidus in the pressure-temperature dependent phase diagram of water has a negative slope provides further complications. Ice can thus melt or freeze from both temperature and pressure variations or variations in both. In order to provide details of the current understanding of water flow in conjunction with deforming ice and to provide understanding for the development of ideas and models, emphasis has been put on the mathematical treatments, which are reproduced in detail. Qualitative results corroborating theory or, perhaps more often, questioning the simplifications made in theory, are also given. The overarching problem with our knowledge of glacier hydrology is the gap between the local theories of processes and the general flow of water in glaciers and ice sheets. Water is often channelized in non-stationary conduits through the ice, features which due to their minute size relative to the size of glaciers and ice sheets are difficult to incorporate in spatially larger models. Since the dynamic response of ice sheets to global warming is becoming a key issue in, e.g. sea-level change studies, the problems of the coupling between the hydrology of an ice sheet and its dynamics is steadily gaining interest. New work is emerging

  3. Sheet Beam Klystron Instability Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bane, K.L.F.; Jensen, A.; Li, Z.; Stupakov, G.; Adolphsen, C.; /SLAC

    2009-05-08

    Using the principle of energy balance we develop a 2D theory for calculating growth rates of instability in a two-cavity model of a sheet beam klystron. An important ingredient is a TE-like mode in the gap that also gives a longitudinal kick to the beam. When compared with a self-consistent particle-in-cell calculation, with sheet beam klystron-type parameters, agreement is quite good up to half the design current, 65 A; at full current, however, other, current-dependent effects come in and the results deviate significantly.

  4. Ice sheet hydrology - a review

    International Nuclear Information System (INIS)

    This report summarizes the theoretical knowledge on water flow in and beneath glaciers and ice sheets and how these theories are applied in models to simulate the hydrology of ice sheets. The purpose is to present the state of knowledge and, perhaps more importantly, identify the gaps in our understanding of ice sheet hydrology. Many general concepts in hydrology and hydraulics are applicable to water flow in glaciers. However, the unique situation of having the liquid phase flowing in conduits of the solid phase of the same material, water, is not a commonly occurring phenomena. This situation means that the heat exchange between the phases and the resulting phase changes also have to be accounted for in the analysis. The fact that the solidus in the pressure-temperature dependent phase diagram of water has a negative slope provides further complications. Ice can thus melt or freeze from both temperature and pressure variations or variations in both. In order to provide details of the current understanding of water flow in conjunction with deforming ice and to provide understanding for the development of ideas and models, emphasis has been put on the mathematical treatments, which are reproduced in detail. Qualitative results corroborating theory or, perhaps more often, questioning the simplifications made in theory, are also given. The overarching problem with our knowledge of glacier hydrology is the gap between the local theories of processes and the general flow of water in glaciers and ice sheets. Water is often channelized in non-stationary conduits through the ice, features which due to their minute size relative to the size of glaciers and ice sheets are difficult to incorporate in spatially larger models. Since the dynamic response of ice sheets to global warming is becoming a key issue in, e.g. sea-level change studies, the problems of the coupling between the hydrology of an ice sheet and its dynamics is steadily gaining interest. New work is emerging

  5. The social balance sheet 2005

    OpenAIRE

    Ph. Delhez; P. Heuse

    2006-01-01

    Each year, the National Bank examines the provisional results of the social balance sheets of Belgian enterprises. As the social balance sheets are not yet all available for 2005, the study is based on a limited population of enterprises, compiled according to the principle of a constant sample. This population is made up of 48,976 enterprises employing around 4,441,000 workers in 2005. The main results of the analysis are as follows. As an average, employment increased by 0.5 p.c. between 20...

  6. Treatment of papermaking tobacco sheet wastewater by electrocoagulation combined with electrochemical oxidation.

    Science.gov (United States)

    Ma, Xiangjuan; Gao, Yang; Huang, Hanping

    2015-01-01

    Attempts were made in this study to examine the efficiency of electrocoagulation (EC) using aluminum (Al) anode and stainless steel net cathode combined with electrochemical oxidation with a β-PbO₂anode or a mixed metal oxide (MMO) anode for treatment of papermaking tobacco sheet wastewater, which has the characteristics of high content of suspended solids (SS), intensive color, and low biodegradability. The wastewater was first subjected to the EC process under 40 mA/cm² of current density, 2.5 g/L of NaCl, and maintaining the original pH of wastewater. After 6 minutes of EC process, the effluent was further treated by electrochemical oxidation. The results revealed that the removal of SS during the EC process was very beneficial to mass transfer of organics during electrochemical oxidation. After the combined process, 83.9% and 82.8% of chemical oxygen demand (COD) removal could be achieved on the β-PbO₂and MMO anodes, respectively. The main components of the final effluent were biodegradable organic acids, such as acetic acid, propionic acid, butyric acid, valeric acid, and hexahyl carbonic acid; the 5-day biochemical oxygen demand/chemical oxygen demand (BOD₅/COD) ratio increased from 0.06 to 0.85 (Al + β-PbO₂) or 0.80 (Al + MMO). Therefore, this integrated process is a promising alternative for pretreatment of papermaking tobacco sheet wastewater prior to biological treatment. PMID:25909726

  7. Biodegradability enhancement of textile wastewater by electron beam irradiation

    Science.gov (United States)

    Kim, Tak-Hyun; Lee, Jae-Kwang; Lee, Myun-Joo

    2007-06-01

    Textile wastewater generally contains various pollutants, which can cause problems during biological treatment. Electron beam radiation technology was applied to enhance the biodegradability of textile wastewater for an activated sludge process. The biodegradability (BOD 5/COD) increased at a 1.0 kGy dose. The biorefractory organic compounds were converted into more easily biodegradable compounds such as organic acids having lower molecular weights. In spite of the short hydraulic retention time (HRT) of the activated sludge process, not only high organic removal efficiencies, but also high microbial activities were achieved. In conclusion, textile wastewater was effectively treated by the combined process of electron beam radiation and an activated sludge process.

  8. "Rational" management of dichlorophenols biodegradation by the microalga Scenedesmus obliquus.

    Directory of Open Access Journals (Sweden)

    Aikaterini Papazi

    Full Text Available The microalga Scenedesmus obliquus exhibited the ability to biodegrade dichlorophenols (dcps under specific autotrophic and mixotrophic conditions. According to their biodegradability, the dichlorophenols used can be separated into three distinct groups. Group I (2,4-dcp and 2,6 dcp - no meta-substitution consisted of quite easily degraded dichlorophenols, since both chloride substituents are in less energetically demanding positions. Group II (2,3-dcp, 2,5-dcp and 3,4-dcp - one meta-chloride was less susceptible to biodegradation, since one of the two substituents, the meta one, required higher energy for C-Cl-bond cleavage. Group III (3,5-dcp - two meta-chlorides could not be biodegraded, since both chlorides possessed the most energy demanding positions. In general, when the dcp-toxicity exceeded a certain threshold, the microalga increased the energy offered for biodegradation and decreased the energy invested for biomass production. As a result, the biodegradation per cell volume of group II (higher toxicity was higher, than group I (lower toxicity and the biodegradation of dichlorophenols (higher toxicity was higher than the corresponding monochlorophenols (lower toxicity. The participation of the photosynthetic apparatus and the respiratory mechanism of microalga to biodegrade the group I and the group II, highlighted different bioenergetic strategies for optimal management of the balance between dcp-toxicity, dcp-biodegradability and culture growth. Additionally, we took into consideration the possibility that the intermediates of each dcp-biodegradation pathway could influence differently the whole biodegradation procedures. For this reason, we tested all possible combinations of phenolic intermediates to check cometabolic interactions. The present contribution bring out the possibility of microalgae to operate as "smart" bioenergetic "machines", that have the ability to continuously "calculate" the energy reserves and "use" the most

  9. Biodegradable Polyphosphazene Based Peptide-Polymer Hybrids

    Directory of Open Access Journals (Sweden)

    Anne Linhardt

    2016-04-01

    Full Text Available A novel series of peptide based hybrid polymers designed to undergo enzymatic degradation is presented, via macrosubstitution of a polyphosphazene backbone with the tetrapeptide Gly-Phe-Leu-Gly. Further co-substitution of the hybrid polymers with hydrophilic polyalkylene oxide Jeffamine M-1000 leads to water soluble and biodegradable hybrid polymers. Detailed degradation studies, via 31P NMR spectroscopy, dynamic light scattering and field flow fractionation show the polymers degrade via a combination of enzymatic, as well as hydrolytic pathways. The peptide sequence was chosen due to its known property to undergo lysosomal degradation; hence, these degradable, water soluble polymers could be of significant interest for the use as polymer therapeutics. In this context, we investigated conjugation of the immune response modifier imiquimod to the polymers via the tetrapeptide and report the self-assembly behavior of the conjugate, as well as its enzymatically triggered drug release behavior.

  10. Purified terephthalic acid wastewater biodegradation and toxicity

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xu-xiang; LUO Xiang; GU Ji-dong; WAN Yu-qiu; CHENG Shu-pei; SUN Shi-lei; ZHU Cheng-jun; LI Wei-xin; ZHANG Xiao-chun; WANG Gui-lin; LU Jian-hua

    2005-01-01

    The biodegradation and toxicity of the purified terephthalic acid(PTA) processing wastewater was researched at NJYZ pilot with the fusant strain Fhhh in the carrier activated sludge process(CASP). Sludge loading rate(SLR) for Fhhh to COD of the wastewater was 1.09 d-1 and to PTA in the wastewater was 0.29 d-1. The results of bioassay at the pilot and calculation with software Ebis3 showed that the 48h-LC50 (median lethal concentration) to Daphnia magna for the PTA concentration in the wastewater was only 1/10 of that for the chemical PTA. There were 5 kinds of benzoate pollutants and their toxicities existing in the wastewater at least. The toxicity parameter value of the pure chemical PTA cannot be used to predicate the PTA wastewater toxicity. The toxicity of the NJYZ PTA wastewater will be discussed in detail in this paper.

  11. Biodegradation of lignin by Agaricus Bisporus

    Energy Technology Data Exchange (ETDEWEB)

    Vane, C.H.; Abbott, G.D.; Head, I.M. [Univ. of Newcastle upon Tyne (United Kingdom)

    1996-12-31

    The lignolytic activity of Agaricus bisporus will be addressed in this paper. Sound and fungally degraded lignins were characterized by Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC-MS), Fourier Transform Infrared Spectroscopy (FnR) and elemental analysis. Fungally degraded lignins displayed increased wt%N, wt%H and wt%O content and decreased wt%C content The FTIR spectrum of decayed lignin showed an increase in the relative intensity of absorption bands assigned to carbonyl and carboxyl functional groups located on the aliphatic side chain and a decrease in absorption bands assigned to aromatic skeletal vibration modes. Semiquantitative Py-GC-MS revealed an 82% decrease in lignin derived pyrolysis products upon biodegradation. No significant increase in pyrolysis products with an oxygenated aliphatic side chain were detected in the fungally degraded lignin however shortening of the aliphatic side chain via cleavage at the {alpha}, {beta} and {gamma} positions was observed.

  12. Lignin biodegradation with laccase-mediator systems

    Directory of Open Access Journals (Sweden)

    Lew Paul Christopher

    2014-03-01

    Full Text Available Lignin has a significant and largely unrealized potential as a source for the sustainable production of fuels and bulk high-value chemicals. It can replace fossil-based oil as a renewable feedstock that would bring about socio-economic and environmental benefits in our transition to a biobased economy. The efficient utilization of lignin however requires its depolymerization to low molecular weight phenolics and aromatics that can then serve as the building blocks for chemical syntheses of high-value products. The ability of laccase to attack and degrade lignin in conjunction with laccase mediators is currently viewed as one of the potential breakthrough applications for lignin valorization. Here we review the recent progress in lignin biodegradation with laccase-mediator systems, and research needs that need to be addressed in this field.

  13. Biodegradation and flushing of MBT wastes.

    Science.gov (United States)

    Siddiqui, A A; Richards, D J; Powrie, W

    2013-11-01

    Mechanical-biological treatment (MBT) processes are increasingly being adopted as a means of diverting biodegradable municipal waste (BMW) from landfill, for example to comply with the EU Landfill Directive. However, there is considerable uncertainty concerning the residual pollution potential of such wastes. This paper presents the results of laboratory experiments on two different MBT waste residues, carried out to investigate the remaining potential for the generation of greenhouse gases and the flushing of contaminants from these materials when landfilled. The potential for gas generation was found to be between 8% and 20% of that for raw MSW. Pretreatment of the waste reduced the potential for the release of organic carbon, ammoniacal nitrogen, and heavy metal contents into the leachate; and reduced the residual carbon remaining in the waste after final degradation from ∼320g/kg dry matter for raw MSW to between 183 and 195g/kg dry matter for the MBT wastes. PMID:23973052

  14. Biodegradation of Petroleum Hydrocarbons in Soil

    Directory of Open Access Journals (Sweden)

    MR Mehrasbi

    2003-09-01

    Full Text Available Biodegradation of petroleum hydrocarbons (20 g/kg dw soil was investigated in 3 media, differing in the kind of petroleum fractions. In the laboratory experiments, during 5 months, the activities of petroleum hydrocarbon-degrading microorganisms and dehydrogenase activity of soil was determined. Gas chromatographic analysis showed the biological decontaminations for gas oil, kerosene and synthetic mixture (gas oil, kerosene and furnace oil are 60 %, 36 % and 55 %, respectively. Dehydrogenase activity which was assessed by TTC technique, correlated significantly positive with the numbers of microorganisms. The Spearman rank correlation coefficients(r in contaminated soils with gas oil, kerosene and synthetic mixture were 0.79, 0.80 and 0.69, respectively.

  15. Gas foamed open porous biodegradable polymeric microspheres.

    Science.gov (United States)

    Kim, Taek Kyoung; Yoon, Jun Jin; Lee, Doo Sung; Park, Tae Gwan

    2006-01-01

    Highly open porous biodegradable polymeric microspheres were fabricated for use as injectable scaffold microcarriers for cell delivery. A modified water-in-oil-in-water (W1/O/W2) double emulsion solvent evaporation method was employed for producing the microspheres. The incorporation of an effervescent salt, ammonium bicarbonate, in the primary W1 droplets spontaneously produced carbon dioxide and ammonia gas bubbles during the solvent evaporation process, which not only stabilized the primary emulsion, but also created well inter-connected pores in the resultant microspheres. The porous microspheres fabricated under various gas foaming conditions were characterized. The surface pores became as large as 20 microm in diameter with increasing the concentration of ammonium bicarbonate, being sufficient enough for cell infiltration and seeding. These porous scaffold microspheres could be potentially utilized for cultivating cells in a suspension manner and for delivering the seeded cells to the tissue defect site in an injectable manner. PMID:16023197

  16. Biodegradation of polyester. Polyester no bunkai sei

    Energy Technology Data Exchange (ETDEWEB)

    Tokiwa, Y. (Agency of Industrial Science and Technology, Tokyo (Japan). Fermentation Research Inst.)

    1991-09-10

    Penicillium sp. 14-3 and penicillium sp. 26-1 can degrade various kinds of polyester. The results of studies made on hydrolysis of polyester by enzyme, hydrolysis of polyester by various kinds of lipase, and degradation of ester type polyurethane by microbes and lipase are introduced. For the improvement of physical properties of aliphatic polyester, aromatic-aliphatic polyester copolymers (CPE) have been synthesized to study the biodegradability. Copolymer in which a number of polyamide (nylon) are alternately introduced (CPAE) to aliphatic polyester has been developed. The result of studies made on the degradability of a blended body of PCL and natural high polymer, and on the collapsibility by lipase of high polymer materials including aliphatic polyamide are introduced. 26 refs., 5 figs., 1 tab.

  17. Biodegradation of concrete intended for their decontamination

    International Nuclear Information System (INIS)

    The decontamination of sub-structural materials represents a stake of high importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those microorganisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

  18. Antibacterial biodegradable Mg-Ag alloys

    Directory of Open Access Journals (Sweden)

    D Tie

    2013-06-01

    Full Text Available The use of magnesium alloys as degradable metals for biomedical applications is a topic of ongoing research and the demand for multifunctional materials is increasing. Hence, binary Mg-Ag alloys were designed as implant materials to combine the favourable properties of magnesium with the well-known antibacterial property of silver. In this study, three Mg-Ag alloys, Mg2Ag, Mg4Ag and Mg6Ag that contain 1.87 %, 3.82 % and 6.00 % silver by weight, respectively, were cast and processed with solution (T4 and aging (T6 heat treatment.The metallurgical analysis and phase identification showed that all alloys contained Mg4Ag as the dominant β phase. After heat treatment, the mechanical properties of all Mg-Ag alloys were significantly improved and the corrosion rate was also significantly reduced, due to presence of silver. Mg(OH2 and MgO present the main magnesium corrosion products, while AgCl was found as the corresponding primary silver corrosion product. Immersion tests, under cell culture conditions, demonstrated that the silver content did not significantly shift the pH and magnesium ion release. In vitro tests, with both primary osteoblasts and cell lines (MG63, RAW 264.7, revealed that Mg-Ag alloys show negligible cytotoxicity and sound cytocompatibility. Antibacterial assays, performed in a dynamic bioreactor system, proved that the alloys reduce the viability of two common pathogenic bacteria, Staphylococcus aureus (DSMZ 20231 and Staphylococcus epidermidis (DSMZ 3269, and the results showed that the killing rate of the alloys against tested bacteria exceeded 90%. In summary, biodegradable Mg-Ag alloys are cytocompatible materials with adjustable mechanical and corrosion properties and show promising antibacterial activity, which indicates their potential as antibacterial biodegradable implant materials.

  19. Biodegradation of crystal violet by Agrobacterium radiobacter.

    Science.gov (United States)

    Parshetti, G K; Parshetti, S G; Telke, A A; Kalyani, D C; Doong, R A; Govindwar, S P

    2011-01-01

    Agrobacterium radiobacter MTCC 8161 completely decolorized the Crystal Violet with 8 hr (10 mg/L) at static anoxic conditions. The decreased decolorization capability by A. radiobacter was observed, when the Crystal Violet concentration was increased from 10 to 100 mg/L. Semi-synthetic medium containing 1% yeast extract and 0.1% NH4C1 has shown 100% decolorization of Crystal Violet within 5 hr. A complete degradation of Crystal Violet by A. radiobacter was observed up to 7 cycles of repeated addition (10 mg/L). When the effect of increasing inoculum concentration on decolorization of Crystal Violet (100 mg/L) was studied, maximum decolorization was observed with 15% inoculum concentration. A significant increase in the activities of laccase (184%) and aminopyrine N-demethylase (300%) in cells obtained after decolorization indicated the involvement of these enzymes in decolorization process. The intermediates formed during the degradation of Crystal Violet were analyzed by gas chromatography and mass spectroscopy (GC/MS). It was detected the presence of N,N,N',N"-tetramethylpararosaniline, [N, N-dimethylaminophenyl] [N-methylaminophenyl] benzophenone, N, N-dimethylaminobenzaldehyde, 4-methyl amino phenol and phenol. We proposed the hypothetical metabolic pathway of Crystal Violet biodegradation by A. radiobacter. Phytotoxicity and microbial toxicity study showed that Crystal Violet biodegradation metabolites were less toxic to bacteria (A. radiobacter, P. aurugenosa and A. vinelandii) contributing to soil fertility and for four kinds of plants (Sorghum bicolor Vigna radiata, Lens culinaris and Triticum aestivum) which are most sensitive, fast growing and commonly used in Indian agriculture. PMID:22128547

  20. Peptide biomarkers as evidence of perchlorate biodegradation.

    Science.gov (United States)

    Bansal, Reema; Crawford, Ronald L; Paszczynski, Andrzej J

    2011-02-01

    Perchlorate is a known health hazard for humans, fish, and other species. Therefore, it is important to assess the response of an ecosystem exposed to perchlorate contamination. The data reported here show that a liquid chromatography-mass spectrometry-based proteomics approach for the detection of perchlorate-reducing enzymes can be used to measure the ability of microorganisms to degrade perchlorate, including determining the current perchlorate degradation status. Signature peptides derived from chlorite dismutase (CD) and perchlorate reductase can be used as biomarkers of perchlorate presence and biodegradation. Four peptides each derived from CD and perchlorate reductase subunit A (PcrA) and seven peptides derived from perchlorate reductase subunit B (PcrB) were identified as signature biomarkers for perchlorate degradation, as these sequences are conserved in the majority of the pure and mixed perchlorate-degrading microbial cultures examined. However, chlorite dismutase signature biomarker peptides from Dechloromonas agitata CKB were found to be different from those in other cultures used and should also be included with selected CD biomarkers. The combination of these peptides derived from the two enzymes represents a promising perchlorate presence/biodegradation biomarker system. The biomarker peptides were detected at perchlorate concentrations as low as 0.1 mM and at different time points both in pure cultures and within perchlorate-reducing environmental enrichment consortia. The peptide biomarkers were also detected in the simultaneous presence of perchlorate and an alternate electron acceptor, nitrate. We believe that this technique can be useful for monitoring bioremediation processes for other anthropogenic environmental contaminants with known metabolic pathways. PMID:21115710

  1. Magnetic Resonance Facility (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-03-01

    This fact sheet provides information about Magnetic Resonance Facility capabilities and applications at NREL's National Bioenergy Center. Liquid and solid-state analysis capability for a variety of biomass, photovoltaic, and materials characterization applications across NREL. NREL scientists analyze solid and liquid samples on three nuclear magnetic resonance (NMR) spectrometers as well as an electron paramagnetic resonance (EPR) spectrometer.

  2. Drinking Water Fact Sheet: Arsenic

    OpenAIRE

    Mesner, Nancy; Daniels, Barbara

    2010-01-01

    This fact sheet provides information about arsenic in drinking water. It includes sections about what arsenic is, where it comes from, health concerns from exposure, drinking water standards, how to know if there is arsenic in a water supply and how to reduce arsenic in drinking water.

  3. Learning from Balance Sheet Visualization

    Science.gov (United States)

    Tanlamai, Uthai; Soongswang, Oranuj

    2011-01-01

    This exploratory study examines alternative visuals and their effect on the level of learning of balance sheet users. Executive and regular classes of graduate students majoring in information technology in business were asked to evaluate the extent of acceptance and enhanced capability of these alternative visuals toward their learning…

  4. Effects of Paper-Mill Sludge as a Mulch versus Topsoil Incorporation on Potassium Uptake and the Grain Yield of Rain-Fed Wheat in a High Specific Surface Loess Soil with Illite Dominance in Clay Fraction

    OpenAIRE

    S Amini; Movahedi Naeini, S. A. R.; Mashayekhi, K.

    2012-01-01

    A field experiment with rain-fed winter wheat investigated the nutritional aspects of paper-mill sludge as a mulch and incorporated into the topsoil. Treatments with chemical fertilizers were also used as controls. Paper-mill sludge used as mulch with high rate (100 MG ha−1) and also the combined N and K mineral fertilizer treatments increased yield when a low potassium otherwise caused potassium deficiency in wheat with high specific surface soil. High soil Ca : K molar ratio by incorporatio...

  5. The soil-water flow system beneath a cotton field in arid north-west China, serviced by mulched drip irrigation using brackish water

    Science.gov (United States)

    Li, Xianwen; Jin, Menggui; Huang, Jinou; Yuan, Jingjing

    2015-02-01

    A field experiment was carried out in southern Xinjiang, China, to reveal soil-water flow pattern beneath a combined plastic-mulch (film) and drip-irrigation system using brackish water. The soil-water flow system (SWFS) was characterized from soil surface to the water table based on observed spatio-temporal distribution of total soil-water potential, water content and electric conductivity. Root suction provided a strong inner sink. The results indicated that SWFS determined the soil salinity and moisture distribution. Drip-irrigation events could leach excess salts from the root zone and provide soil conditions with a tolerable salinity level that supports the growth of cotton. High-salinity strips were formed along the wetting front and at the bare soil surface. Hydrogeology conditions, irrigation regime, climate, plant growth and use of mulch would affect potential sources and sinks, boundary conditions and the size of the SWFS. At depth 0-60 cm, the soil salinity at the end of the irrigation season was 1.9 times that at the beginning. Beneath the mulch cover, the soil-water content in the `wide rows' zone (55 cm between the two rows with no drip line) was higher than that in the `narrow rows' zone (15 cm between the two rows with a drip line) due to the strong root-water uptake. The downward water flow below the divergent curved surface of zero flux before irrigation, and the water-table fluctuation with irrigation events, indicated that excessive irrigation occurred.

  6. 地膜覆盖云杉播种苗越冬试验%Test on Qinghai Spruce Seedlings Overwinter with Plastic Film Mulching

    Institute of Scientific and Technical Information of China (English)

    韩英

    2012-01-01

    Using mulch, straw and branches in Qinghai spruce seedlings overwintering seedlings of different cover design treatment, test results show that the over winter effect plastic film cover was best, survival rate was 98.2%.%利用地膜、麦草和树枝对青海云杉越冬苗进行不同覆盖物设计处理试验,结果表明地膜覆盖越冬效果最好,成活率达98.2%。

  7. Towards an integrated assessment of the impacts of forest residue mulching following wildfire in eucalypt plantations in north-central Portugal

    Science.gov (United States)

    Keizer, Jan Jacob; Abrantes, Nelson; Bastos, Ana; Brandsma, Micha; Campos, Isabel; Faria, Silvia; Malvar, Maruxa; Martins, Martinho; João Oliveira, Maria; Pimpão, Gabriel; Prats, Sergio; Puga, João; Ribeiro, Cristina; Rocha, João; Santos, Liliana; Serpa, Dalila; Silva, Flávio; Silva, Tiago; Valente, Sandra; Vieira, Diana

    2016-04-01

    In the framework of the EU-FP7 project RECARE (www.recare-project.eu) and, in particular, its WP6, the University of Aveiro partner has recently started testing two measures against the soil threat of post-fire erosion by water in an area in north-central Portugal, close to Coimbra that burnt during the summer of 2015. These measures - mulching with forest slash residues and contour ploughing - had been selected by the local and external stakeholders involved in the project, through two subsequent stakeholder workshops. While contour ploughing has still not taken place, the mulching was already carried out, using residues from eucalypt plantations as the burnt areas was dominated by eucalypt plantations, and applying them in a homogeneous fashion at two contrasting application rates, i.e. a "standard" rate of approximately 10 Mg ha-1 and a "reduced" rate of about 3 Mg ha-1. The standard rate was selected for having proved effective in reducing post-fire runoff and erosion in previous field studies in the region (Prats et al., 2012, 2014, 2015a), while the reduced rate had been found to be nearly as effective as the standard rate in a recent study in the hydraulic laboratory of the University of Coimbra (Prats et al., 2015b). Unlike the referred prior studies, however, the present study will also assess the impacts of mulching on two other soil threats - i.e. decline in soil organic matter and in soil biodiversity - and, ultimately, will compare the two measures in terms of their consequences for soil-based ecosystem services, using the framework being developed by RECARE (Schwilch et al. in Stolte et al., 2016). The proposed presentation will show the first results on the effects of the two mulch application rates on post-fire runoff as well as the associated losses of sediments, organic matter/C and nutrients (N, P), and on selected indicators of soil biological activity and diversity. Prats et al., 2015a (in press). LD&D (doi: 10.1002/ldr.2422) Prats et al., 2015

  8. The Effects of Land Configuration and Wood-Shavings Mulch on the Properties of a Sandy Loam Soil in Northeast Nigeria. 2. Changes in Physical Properties

    Directory of Open Access Journals (Sweden)

    Chiroma, AM.

    2006-01-01

    Full Text Available Mulching and ridge tillage are proven technologies for improving soil productivity in semi-arid regions. Yet data quantifying the combined influences of these practices are limited. Our objectives were to determine the changes in selected physical properties of a sandy loam after 4-years of annual tillage and wood-shavings mulching. The tillage and wood-shavings treatments consisted of: Flat bed (FB, Open ridge (OR, Tiedridge (TR, FBM, ORM and TRM were same as FB, OR and TR, respectively except that wood-shavings at a rate of 10 t/ha were surface applied ≈ 2 weeks after sowing each year to serve as both a mulch and an organic amendment. At the end of the trial in 2002, bulk density, penetration resistance, total porosity and soil water content from each of 0-0.075, 0.075-0.15 and 0.15-0.30 m depths were determined. Composite samples from the surface (0.075 and 0.075-0.15 m layers from 3 replicates of each treatment were also collected for the determination of wet aggregate stability and from 0-0.15 m and 0.15-0.30 m layers for determination of saturated hydraulic conductivity (Ksat. After 4 years of annual tillage and addition of woodshavings, soil bulk density and penetration resistance were consistently lower and total porosity higher in the FBM, ORM and TRM treatments than in the FB, OR and TR treatments. Penetration resistance in all treatments was strongly related to soil water content. A 'hoe pan' was established below 0.15 m depth beneath the furrows of the ridged treatments. This could be attributed to human traffic during field operations and ponding of water, which occurred in the furrows following heavy rains. Wet aggregate stability estimated as the proportion of aggregates of size > 0.25 mm (macro-aggregates in the 0-0.15 m layer were significantly (P< 0.05 higher under FBM, ORM and TRM than under FB, OR or TR treatments. Ksat was not influenced by either tillage or wood-shavings treatments but were higher for the mulched plots

  9. [Effects of plastic film mulching and rain harvesting modes on chlorophyll fluorescence characteristics, yield and water use efficiency of dryland maize].

    Science.gov (United States)

    Li, Shang-Zhong; Fan, Ting-Lu; Wang, Yong; Zhao, Gang; Wang, Lei; Tang, Xiao-Ming; Dang, Yi; Zhao, Hui

    2014-02-01

    The differences on chlorophyll fluorescence parameters, yield and water use efficiency of dryland maize were compared among full plastic film mulching on double ridges and planting in catchment furrows (FFDRF), half plastic film mulching on double ridges and planting in catchment furrows (HFDRF), plastic film mulching on ridge and planting in film-side (FS), and flat planting with no plastic film mulching (NM) under field conditions in dry highland of Loess Plateau in 2007-2012. The results showed that fluorescence yield (Fo), the maximum fluorescence yield (Fm), light-adapted fluorescence yield when PS II reaction centers were totally open (F), light-adapted fluorescence yield when PS II reaction centers closed (Fm'), the maximal photochemical efficiency of PS II (Fv/Fm), the actual photochemical efficiency of PS II in the light (Phi PS II), the relative electron transport rate (ETR), photochemical quenching (qP) and non-photochemical quenching (qN) in maize leaves of FFDRF were higher than that of control (NM), and the value of 1-qP was lower than that of control, at 13:00, chlorophyll fluorescence parameters values of FFDRF was significantly higher than control, which were increased by 5.3%, 56.8%, 10.7%, 36.3%, 23.6%, 56.7%, 64.4%, 45.5%, 23.6% and -55.6%, respectively, compared with the control. Yield and water use efficiency of FFDRF were the highest in every year no matter dry year, normal year, humid year and hail disaster year. Average yield and water use efficiency of FFDRF were 12,650 kg x hm(-2) and 40.4 kg x mm(-1) x hm(-2) during 2007-2012, increased by 57.8% and 61.6% compared with the control, respectively, and also significantly higher compared with HFDRF and PS. Therefore, it was concluded that FFDRF had significantly increased the efficiency of light energy conversion and improved the production capacity of dryland maize. PMID:24830246

  10. Orientational ordering in crumpled elastic sheets

    OpenAIRE

    Cambou, Anne Dominique; Menon, Narayanan

    2014-01-01

    We report an experimental study of the development of orientational order in a crumpled sheet, with a particular focus on the role played by the geometry of confinement. Our experiments are performed on elastomeric sheets immersed in a fluid, so that the effects of plasticity and friction are suppressed. When the sheet is crumpled either axially or radially within a cylinder, we find that the sheet aligns with the flat or the curved wall, depending on the aspect ratio of the cylinder. Nematic...

  11. Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles

    International Nuclear Information System (INIS)

    A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

  12. Biodegradation of waste PET based copolyesters in thermophilic anaerobic sludge

    Czech Academy of Sciences Publication Activity Database

    Hermanová, S.; Šmejkalová, P.; Merna, J.; Zarevúcka, Marie

    2015-01-01

    Roč. 111, Jan (2015), s. 176-184. ISSN 0141-3910 Institutional support: RVO:61388963 Keywords : poly(ethylene terephthalate) * copolymers * sludge * biodegradation * hydrolysis * waste Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.163, year: 2014

  13. Biodegradation of cycloalkane carboxylic acids in oil sand tailings

    International Nuclear Information System (INIS)

    The biodegradation of both an n-alkane and several carboxylated cycloalkanes was examined experimentally within tailings produced by the extraction of bitumen from the Athabasca oil sands. The carboxylated cycloalkanes examined were structurally similar to naphthenic acids that have been associated with the acute toxicity of oil sand tailings. The biodegradation potential of naphthenic acids was estimated by determining the biodegradation of both the carboxylated cycloalkanes and hexadecane in oil sand tailings. Carboxylated cycloalkanes were biodegraded within oil sands tailings, although compounds with methyl substitutions on the cycloalkane ring were more resistant to microbial degradation. Microbial activity against hexadecane and certain carboxylated cycloalkanes was found to be nitrogen and phosphorus limited. 21 refs., 3 refs., 1 tab

  14. Fade to Green: A Biodegradable Stack of Microbial Fuel Cells.

    Science.gov (United States)

    Winfield, Jonathan; Chambers, Lily D; Rossiter, Jonathan; Stinchcombe, Andrew; Walter, X Alexis; Greenman, John; Ieropoulos, Ioannis

    2015-08-24

    The focus of this study is the development of biodegradable microbial fuel cells (MFCs) able to produce useful power. Reactors with an 8 mL chamber volume were designed using all biodegradable products: polylactic acid for the frames, natural rubber as the cation-exchange membrane and egg-based, open-to-air cathodes coated with a lanolin gas diffusion layer. Forty MFCs were operated in various configurations. When fed with urine, the biodegradable stack was able to power appliances and was still operational after six months. One useful application for this truly sustainable MFC technology includes onboard power supplies for biodegradable robotic systems. After operation in remote ecological locations, these could degrade harmlessly into the surroundings to leave no trace when the mission is complete. PMID:26212495

  15. State-of-the-art of biodegradable composite materials

    International Nuclear Information System (INIS)

    Nowadays, the market demand for environment friendly materials is in strong growth. The biodegradable composites (biodegradable fibres and polymers) mainly extracted from renewable resources will be a major contributor to the production of new industrial high performance products partially solving the problem of waste management. At the end of the lifetime, a structural bio-composite could be be crushed and recycled through a controlled industrial composting process. This the state-of-the-art report focuses on the biopolymers the vegetable fibres properties, the mechanisms of biodegradation and the examples of biodegradable composites. Eco-design of new products requires these new materials for which a life cycle analysis is nevertheless necessary to validate their environmental benefits. (authors)

  16. Kinetics of Enzyme Biodegradation of New Synthesized Copolymers

    Directory of Open Access Journals (Sweden)

    Rosa Mateva

    2005-04-01

    Full Text Available Block copolymers of the poly-(hexanlactam-co-block-poly-(?-valerolactone from ABA-type were synthesized via anionic polymerization of hexanlactam (HL with the sodium salt of hexanlactam (Na-HL as an initiator and polymeric activator (PAC. PAC, on the base of poly-?-valerolactone (PVL, was used as a soft central block. Synthetic PVL is very attractive biomaterial - nontoxic, biocompatibility and biodegradable polyester[5-8]. Modification of HL with PVL, renders these system biodegradable[1]. Isolated copolymers were characterized by various spectroscopic techniques. The effect of the chemical and physical structure of the synthesized block copolymers on the biodegradation was investigated. Biodegradation of block copolyester amides was studied by means of lipase and involves the enzymatic hydrolysis of ester groups in PVL.

  17. 麦秸覆盖条件下土壤蒸发阻力及蒸发模拟%Modeling resistance of soil evaporation and soil evaporation under straw mulching

    Institute of Scientific and Technical Information of China (English)

    李艳; 刘海军; 黄冠华

    2015-01-01

    模拟覆盖条件下的土壤蒸发对于农田水管理具有重要的作用。该文分析了留茬和秸秆覆盖模式下影响土面蒸发的因素,提出了留茬覆盖模式下蒸发阻力和土面蒸发模型,基于试验数据确定了公式中的参数。主要结果和结论:当表层2 cm土壤含水率高于0.23 cm3/cm3(约60%田持)时,土面相对蒸发量(土面蒸发量与20 cm蒸发皿蒸发量比值)基本保持稳定;当表层2 cm土壤含水率在0.05~0.23 cm3/cm3之间时,土面相对蒸发量随土壤含水率的降低而线性减小。覆盖会明显降低土壤蒸发,覆盖阻力随秸秆覆盖量增加呈指数增长。当表层2 cm土壤含水率在0.05~0.23 cm3/cm3之间时,土壤表面阻力随土壤体积含水率降低而线性增加。验证结果显示建立的土面蒸发模型及相应阻力参数能较好的模拟覆盖条件下的土面蒸发量。%Evapotranspiration is the main way of soil water depletion in field, and soil evaporation is an important part of evapotranspiration, and it may account for 32%-50%of the total evapotranspiration during the whole crop growth period. Soil evaporation does little effect on the formation of crop biomass and yield, so reducing soil evaporation is important for improving water use efficiency and agricultural water saving management. In recent years, straw mulching has been used widely due to its capability of improving soil structure, increasing soil organic matter, reducing soil evaporation and maintaining soil water content. Mulching affects exchange of energy and heat between soil surface and free air, so the mechanism for soil evaporation under mulching condition may be different from that without mulching. Considering the fast development of straw mulching, therefore modeling soil evaporation under straw mulching is of important for making agricultural water management. In this paper, the factors (soil water content and mulching amount) that affect soil

  18. On the possible eigenoscillations of neutral sheets

    International Nuclear Information System (INIS)

    A neutral sheet model with hyperbolic tangent equilibrium magnetic field and hyperbolic square secant density profiles is considered. It is shown that the equation for small oscillations takes the form of an eigenvalue oscillation problem. Computed eigenfrequencies of the geomagnetic neutral sheet were found to be in the range of the resonant frequencies of the geomagnetic plasma sheet computed by other authors

  19. 21 CFR 878.4025 - Silicone sheeting.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Silicone sheeting. 878.4025 Section 878.4025 Food... DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4025 Silicone sheeting. (a) Identification. Silicone sheeting is intended for use in the management of closed...

  20. Isomer-Specific Biodegradation and Chemical Oxidation of Nonylphenol

    OpenAIRE

    Lu, Zhijiang

    2014-01-01

    Nonylphenol (NP), a well-known environmental estrogen with numerous isomers, is commonly treated as a single compound in the evaluation of its environmental occurrence, fate and transport, treatment removal and toxicity. Recent studies showed that NP isomers exhibited different estrogenicity and biodegradability. However, at present little systematic information is available on its isomer-specific biodegradation and chemical oxidation under natural and engineered conditions.We comprehensively...

  1. Comparative study on the biodegradability of morpholinium herbicidal ionic liquids

    OpenAIRE

    Ławniczak, Łukasz; Materna, Katarzyna; Framski, Grzegorz; Szulc, Alicja; Syguda, Anna

    2015-01-01

    This study focused on evaluating the toxicity as well as primary and ultimate biodegradability of morpholinium herbicidal ionic liquids (HILs), which incorporated MCPA, MCPP, 2,4-D or Dicamba anions. The studied HILs were also subjected to determination of surface active properties in order to assess their influence on toxicity and biodegradability. The study was carried out with microbiota isolated from different environmental niches: sediments from river channel, garden soil, drainage trenc...

  2. Biodegradable Nanocomposite Films Based on Sodium Alginate and Cellulose Nanofibrils

    OpenAIRE

    B. Deepa; Eldho Abraham; Pothan, Laly A; Nereida Cordeiro; Marisa Faria; Sabu Thomas

    2016-01-01

    Biodegradable nanocomposite films were prepared by incorporation of cellulose nanofibrils (CNF) into alginate biopolymer using the solution casting method. The effects of CNF content (2.5, 5, 7.5, 10 and 15 wt %) on mechanical, biodegradability and swelling behavior of the nanocomposite films were determined. The results showed that the tensile modulus value of the nanocomposite films increased from 308 to 1403 MPa with increasing CNF content from 0% to 10%; however, it decreased with further...

  3. Biodegradation of Para Amino Acetanilide by Halomonas sp. TBZ3

    OpenAIRE

    Hajizadeh, Nader; Sefidi Heris, Youssof; Zununi Vahed, Sepideh; Vallipour, Javad; Hejazi, Mohammad Amin; Golabi, Sayyed Mahdi; Asadpour-Zeynali, Karim; Hejazi, Mohammad Saeid

    2015-01-01

    Background: Aromatic compounds are known as a group of highly persistent environmental pollutants. Halomonas sp. TBZ3 was isolated from the highly salty Urmia Lake of Iran. In this study, characterization of a new Halomonas isolate called Halomonas sp. TBZ3 and its employment for biodegradation of para-amino acetanilide (PAA), as an aromatic environmental pollutant, is described. Objectives: This study aimed to characterize the TBZ3 isolate and to elucidate its ability as a biodegradative age...

  4. Study of the biodegradation in soil of new generation plactics

    OpenAIRE

    Siotto,

    2011-01-01

    The intense use of plastic contributes to increase the amount of municipal waste that are generally disposed in landfill. For some applications and sectors, an important alternative to the conventional plastic materials can be found in the use of the new generation materials: the biodegradable polymers. Their use can be an alternative to landfill disposal and can thus reduce the cost of waste management and the accumulation in the environment. The biodegradable polymers, in fact, are used by ...

  5. Biodegradation of Asphalt Cement-20 by Aerobic Bacteria

    OpenAIRE

    Pendrys, John P.

    1989-01-01

    Seven gram-negative, aerobic bacteria were isolated from a mixed culture enriched for asphalt-degrading bacteria. The predominant genera of these isolates were Pseudomonas, Acinetobacter, Alcaligenes, Flavimonas, and Flavobacterium. The mixed culture preferentially degraded the saturate and naphthene aromatic fractions of asphalt cement-20. A residue remained on the surface which was resistant to biodegradation and protected the underlying asphalt from biodegradation. The most potent asphalt-...

  6. Biodegradability determination of municipal waste: an evaluation of methods

    OpenAIRE

    Godley, Andrew R.; Lewin, Kathy; Graham, Adele; Barker, H.; Smith, Richard

    2004-01-01

    The Environment Agency is required to monitor the diversion of biodegradable municipal waste (BMW) from landfill. Reliable methods are needed to measure the biodegradability of municipal waste, both as mixed municipal waste and as individually separated fractions. An evaluation of several methods was carried out using a variety of organic materials typically found in municipal solid waste. The assessment considered biological and non-biological methods to determine which provid...

  7. Critical evaluation of biodegradable polymers used in nanodrugs

    OpenAIRE

    Marin E; Briceño MI; Caballero-George C

    2013-01-01

    Edgar Marin,1–3 Maria Isabel Briceño,2 Catherina Caballero-George11Unit of Pharmacology, Center of Biodiversity and Drug Discovery, Institute of Scientific Research and High Technology Services, 2Nano Dispersions Technology, Panama, Republic of Panama; 3Department of Biotechnology, Archaria Nagarjuna University, Guntur, IndiaAbstract: Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, ...

  8. Biodegradation and biocompatibility of a degradable chitosan vascular prosthesis

    OpenAIRE

    Kong, Xiaoying; Xu, Wenhua

    2015-01-01

    An instrument made by ourselves was used to fabricate biodegradable chitosan-heparin artificial vascular prosthesis with small internal diameter (2 mm) and different crosslinking degree from biodegradable chitosan, chitosan derivates and heparin. In vivo and in vitro degradation studies, inflammatory analysis and electron microscope scanning of this artificial vascular prosthesis were performed. It was observed that 50% of the prosthesis decomposed in vivo and was replaced by natural tissues....

  9. Factors influencing crude oil biodegradation by Yarrowia lipolytica

    OpenAIRE

    Tatiana Felix Ferreira; Maria Alice Zarur Coelho; Maria Helena Miguez da Rocha-Leão

    2012-01-01

    Yarrowia lipolytica is unique strictly aerobic yeast with the ability to efficiently degrade hydrophobic substrates such as n-alkenes, fatty acids, glycerol and oils. In the present work, a 2(4) full factorial design was used to investigate the influence of the independent variables of temperature, agitation, initial cell concentration and initial petroleum concentration on crude oil biodegradation. The results showed that all variables studied had significant effects on the biodegradation pr...

  10. Removal of Textile Dyestufes From Wastewater by Adsorptive Biodegradation

    OpenAIRE

    KAPDAN, İlgi KARAPINAR; KARGI, Fikret

    2000-01-01

    Removal of dyestuffs from a synthetic wastewater by adsorptive biodegradation was investigated in this study. The dyestuff adsorption capacities of granular, powdered activated carbon (GAC and PAC) and low-cost adsorbents such as zeolite, wood chips and wood ash were evaluated in order to obtain a low-cost adsorbent for use in an activated sludge unit. Then various activated sludge cultures were tested for biodegradation of a selected dyestuff. An activated sludge unit with the selected activ...

  11. Kinetics of Enzyme Biodegradation of New Synthesized Copolymers

    OpenAIRE

    Rosa Mateva; Natalia Toncheva; Lubov Yotova

    2005-01-01

    Block copolymers of the poly-(hexanlactam)-co-block-poly-(?-valerolactone) from ABA-type were synthesized via anionic polymerization of hexanlactam (HL) with the sodium salt of hexanlactam (Na-HL) as an initiator and polymeric activator (PAC). PAC, on the base of poly-?-valerolactone (PVL), was used as a soft central block. Synthetic PVL is very attractive biomaterial - nontoxic, biocompatibility and biodegradable polyester[5-8]. Modification of HL with PVL, renders these system biodegradable...

  12. Base Oils Biodegradability Prediction with Data Mining Techniques

    OpenAIRE

    Malika Trabelsi; Saloua Saidane; Sihem Ben Abdelmelek

    2010-01-01

    In this paper, we apply various data mining techniques including continuous numeric and discrete classification prediction models of base oils biodegradability, with emphasis on improving prediction accuracy. The results show that highly biodegradable oils can be better predicted through numeric models. In contrast, classification models did not uncover a similar dichotomy. With the exception of Memory Based Reasoning and Decision Trees, tested classification techniques achieved high classifi...

  13. BACTERIAL BIODEGRADATION OF PERMETRINA AND CIPERMETRINA PESTICIDES IN CULTURE LOT

    OpenAIRE

    José C. Mendoza; Yazmin S. Perea; Jaime A. Salvador; Janette A. Morales; Gabriela Pérez

    2011-01-01

    The biodegradation of permetrhin and cypermethrin (50 and 100 mg/L) with Pseudomonas putida, Pseudomonas mendocina, Chromobacterium violaceum and Burkholderia cepacia in batch reactors was studied. The strain of Pseudomonas putida and Pseudomonas mendocina showed a greater capability of biodegradation of pesticides, after 5 days, this is of 65% for both pesticides and after the 15 days it practically stays constant, being of until 95% for permetrina to 50 and 100 mg/l and for cipermetrina fr...

  14. Biodegradation of bioaccessible textile azo dyes by Phanerochaete chrysosporium

    OpenAIRE

    Martins, Maria Adosinda; Ferreira, Isabel C.F.R.; Santos, Isabel; Queiroz, Maria João R. P.; Lima, Nelson

    2000-01-01

    Azo dyes are important chemical pollutants of industrial origin. Textile azo dyes with bioaccessible groups for lignin degrading fungi, such as 2-methoxyphenol (guaiacol) and 2,6-dimethoxyphenol (syringol), were synthesised using different aminobenzoic and aminosulphonic acids as diazo components. The inocula of the best biodegradation assays were obtained from a pre-growth medium (PAM), containing one of the synthesised dyes. The results of the dye biodegradation assays were eval...

  15. Development of biodegradable magnesium alloy stents with coating

    OpenAIRE

    Lorenza Petrini; Wei Wu; Dario Gastaldi; Lina Altomare; Silvia Farè; Francesco Migliavacca; Ali Gökhan Demir; Barbara Previtali; Maurizio Vedani

    2014-01-01

    Biodegradable stents are attracting the attention of many researchers in biomedical and materials research fields since they can absolve their specific function for the expected period of time and then gradually disappear. This feature allows avoiding the risk of long-term complications such as restenosis or mechanical instability of the device when the vessel grows in size in pediatric patients. Up to now biodegradable stents made of polymers or magnesium alloys have been propose...

  16. Assessment of the biodegradability of xanthan in offshore injection water

    OpenAIRE

    Hovland, Beate

    2015-01-01

    The application of biopolymers in EOR operations is considered environmental friendly compared to synthetic polymers. However, microbial degradation of the biopolymers may lead to a deterioration of effect in EOR applications. This thesis is part of an industrial project conducted by UNI Research CIPR for Statoil ASA, were the aim is to assess biodegradation of xanthan at specific oil field conditions. Investigation of the biodegradation of xanthan was perform...

  17. The effects of plastic film mulching on maize growth and water use in dry and rainy years in Northeast China.

    Science.gov (United States)

    Xu, Jie; Li, Congfeng; Liu, Huitao; Zhou, Peilu; Tao, Zhiqiang; Wang, Pu; Meng, Qingfeng; Zhao, Ming

    2015-01-01

    Plastic film mulching (PM) has been widely used to improve maize (Zea mays L.) yields and water use efficiency (WUE) in Northeast China, but the effects of PM in a changing climate characterized by highly variable precipitation are not well understood. Six site-year field experiments were conducted in the dry and rainy years to investigate the effects of PM on maize growth, grain yield, and WUE in Northeast China. Compared to crops grown without PM treatment (control, CK), PM significantly increased the grain yield by 15-26% in the dry years, but no significant yield increase was observed in the rainy years. Yield increase in the dry years was mainly due to a large increase in dry matter accumulation pre-silking compared to the CK, which resulted from a greater dry matter accumulation rate due to the higher topsoil temperature and water content. As a result, the WUE of the crops that underwent PM (3.27 kg m(-3)) treatment was also increased by around 16% compared to the CK, although the overall evapotranspiration was similar between the two treatments. In the rainy years, due to frequent precipitation and scant sunshine, the topsoil temperature and water content in the field that received PM treatment was improved only at some stages and failed to cause higher dry matter accumulation, except at the 8th leaf stage. Consequently, the grain yield and WUE were not improved by PM in the rainy years. In addition, we found that PM caused leaf senescence at the late growth stage in both dry and rainy years. Therefore, in practice, PM should be applied cautiously, especially when in-season precipitation is taken into account. PMID:25970582

  18. Forest litter as the mulch improving growth and ectomycorrhizal diversity of bare-root Scots pine (Pinus sylvestris seedlings

    Directory of Open Access Journals (Sweden)

    Aučina A

    2015-08-01

    Full Text Available In this paper, we report the influence of pine, oak and spruce forest litter on the growth and ectomycorrhizal (ECM formation of Scots pine seedlings after the first growing season in a bare-root forest nursery. The mixture of collected forest litters and humus were used to obtain a 20-cm mulching layer on the prepared seedbeds. The concentrations of all nutrients and the C/N ratio of growth media were significantly higher in forest litter treatments than in negative control represented by mineral soil without litter. Addition of each forest litter type significantly enhanced pine seedling height and root-collar diameter compared to negative control. A significant positive influence on dry mass of stem, needles, roots and total dry mass of the seedling has been found only for pine litter. Based on molecular identification, seven ECM fungal taxa (Wilcoxina mikolae, Suillus luteus, Cenococcum geophilum, Meliniomyces bicolor, Laccaria laccata, unidentified Atheliaceae, unidentified Ascomycetes were distinguished in the observed mycorrhizal communities. Each forest litter type significantly increased the total number of mycorrhizal tips and ECM fungal diversity compared to the control soil. However, results showed a lack of significant differences in species composition and relative abundance of ECM fungi between different litter types. Such result suggests that forest litter has not been a key source of inoculum for tested fungal species, as root systems of all pine seedlings from different litter types were dominated by a few nursery- adapted ECM fungi, probably originating from natural air-borne inoculum. Our data rather indicate that forest litter considerably improves environmental conditions for development of ECM fungi previously present in the nursery soil. Therefore, any of the forest litter types used in our studies may be able to promote planting stock quality on a small scale in the nursery phase.

  19. Geometry of thin liquid sheet flows

    Science.gov (United States)

    Chubb, Donald L.; Calfo, Frederick D.; Mcconley, Marc W.; Mcmaster, Matthew S.; Afjeh, Abdollah A.

    1994-01-01

    Incompresible, thin sheet flows have been of research interest for many years. Those studies were mainly concerned with the stability of the flow in a surrounding gas. Squire was the first to carry out a linear, invicid stability analysis of sheet flow in air and compare the results with experiment. Dombrowski and Fraser did an experimental study of the disintegration of sheet flows using several viscous liquids. They also detected the formulation of holes in their sheet flows. Hagerty and Shea carried out an inviscid stability analysis and calculated growth rates with experimental values. They compared their calculated growth rates with experimental values. Taylor studied extensively the stability of thin liquid sheets both theoretically and experimentally. He showed that thin sheets in a vacuum are stable. Brown experimentally investigated thin liquid sheet flows as a method of application of thin films. Clark and Dumbrowski carried out second-order stability analysis for invicid sheet flows. Lin introduced viscosity into the linear stability analysis of thin sheet flows in a vacuum. Mansour and Chigier conducted an experimental study of the breakup of a sheet flow surrounded by high-speed air. Lin et al. did a linear stability analysis that included viscosity and a surrounding gas. Rangel and Sirignano carried out both a linear and nonlinear invisid stability analysis that applies for any density ratio between the sheet liquid and the surrounding gas. Now there is renewed interest in sheet flows because of their possible application as low mass radiating surfaces. The objective of this study is to investigate the fluid dynamics of sheet flows that are of interest for a space radiator system. Analytical expressions that govern the sheet geometry are compared with experimental results. Since a space radiator will operate in a vacuum, the analysis does not include any drag force on the sheet flow.

  20. Ohm's law for a current sheet

    Science.gov (United States)

    Lyons, L. R.; Speiser, T. W.

    1985-01-01

    The paper derives an Ohm's law for single-particle motion in a current sheet, where the magnetic field reverses in direction across the sheet. The result is considerably different from the resistive Ohm's law often used in MHD studies of the geomagnetic tail. Single-particle analysis is extended to obtain a self-consistency relation for a current sheet which agrees with previous results. The results are applicable to the concept of reconnection in that the electric field parallel to the current is obtained for a one-dimensional current sheet with constant normal magnetic field. Dissipated energy goes directly into accelerating particles within the current sheet.

  1. Imaging with parallel ray-rotation sheets

    CERN Document Server

    Hamilton, Alasdair C

    2008-01-01

    A ray-rotation sheet consists of miniaturized optical components that function - ray optically - as a homogeneous medium that rotates the local direction of transmitted light rays around the sheet normal by an arbitrary angle [A. C. Hamilton et al., arXiv:0809.2646 (2008)]. Here we show that two or more parallel ray-rotation sheets perform imaging between two planes. The image is unscaled and un-rotated. No other planes are imaged. When seen through parallel ray-rotation sheets, planes that are not imaged appear rotated, whereby the rotation angle changes with the ratio between the observer's and the object plane's distance from the sheets.

  2. Thiol click modification of cyclic disulfide containing biodegradable polyurethane urea elastomers.

    Science.gov (United States)

    Fang, Jun; Ye, Sang-Ho; Wang, Jing; Zhao, Ting; Mo, Xiumei; Wagner, William R

    2015-05-11

    Although the thiol click reaction is an attractive tool for postpolymerization modification of thiolmers, thiol groups are easily oxidized, limiting the potential for covalent immobilization of bioactive molecules. In this study, a series of biodegradable polyurethane elastomers incorporating stable cyclic disulfide groups was developed and characterized. These poly(ester urethane)urea (PEUU-SS) polymers were based on polycaprolactone diol (PCL), oxidized dl-dithiothreitol (O-DTT), lysine diisocyanate (LDI), or butyl diisocyanate (BDI), with chain extension by putrescine. The ratio of O-DTT:PCL was altered to investigate different levels of potential functionalization. PEG acrylate was employed to study the mechanism and availability of both bulk and surface click modification of PEUU-SS polymers. All synthesized PEUU-SS polymers were elastic with breaking strengths of 38-45 MPa, while the PEUU-SS(LDI) polymers were more amorphous, possessing lower moduli and relatively small permanent deformations versus PEUU-SS(BDI) polymers. Variable bulk click modification of PEUU-SS(LDI) polymers was achieved by controlling the amount of reduction reagent, and rapid reaction rates occurred using a one-pot, two-step process. Likewise, surface click reaction could be carried out quickly under mild, aqueous conditions. Furthermore, a maleimide-modified affinity peptide (TPS) was successfully clicked on the surface of an electrospun PEUU-SS(BDI) fibrous sheet, which improved endothelial progenitor cell adhesion versus corresponding unmodified films. The cyclic disulfide containing biodegradable polyurethanes described provide an option for cardiovascular and other soft tissue regenerative medicine applications where a temporary, elastic scaffold with designed biofunctionality from a relatively simple click chemistry approach is desired. PMID:25891476

  3. Evaluation of the biodegradation of Alaska North Slope oil in microcosms using the biodegradation model BIOB

    Directory of Open Access Journals (Sweden)

    Jagadish eTorlapati

    2014-05-01

    Full Text Available We present the details of a numerical model, BIOB that is capable of simulating the biodegradation of oil entrapped in the sediment. The model uses Monod kinetics to simulate the growth of bacteria in the presence of nutrients and the subsequent consumption of hydrocarbons. The model was used to simulate experimental results of Exxon Valdez oil biodegradation in laboratory columns (Venosa et al. (2010. In that study, samples were collected from three different islands: Eleanor Island (EL107, Knight Island (KN114A, and Smith Island (SM006B, and placed in laboratory microcosms for a duration of 168 days to investigate oil bioremediation through natural attenuation and nutrient amendment. The kinetic parameters of the BIOB model were estimated by fitting to the experimental data using a parameter estimation tool based on Genetic Algorithms (GA. The parameter values of EL107 and KN114A were similar whereas those of SM006B were different from the two other sites; in particular biomass growth at SM006B was four times slower than at the other two islands. Grain size analysis from each site revealed that the specific surface area per unit mass of sediment was considerably lower at SM006B, which suggest that the surface area of sediments is a key control parameter for microbial growth in sediments. Comparison of the BIOB results with exponential decay curves fitted to the data indicated that BIOB provided better fit for KN114A and SM006B in nutrient amended treatments, and for EL107 and KN114A in natural attenuation. In particular, BIOB was able to capture the initial slow biodegradation due to the lag phase in microbial growth. Sensitivity analyses revealed that oil biodegradation at all three locations were sensitive to nutrient concentration whereas SM006B was sensitive to initial biomass concentration due to its slow growth rate. Analyses were also performed to compare the half-lives of individual compounds with the decay rate of the overall PAH.

  4. Biodegradation and surfactant-mediated biodegradation of diesel fuel by 218 microbial consortia are not correlated to cell surface hydrophobicity

    Energy Technology Data Exchange (ETDEWEB)

    Owsianiak, Mikolaj; Szulc, Alicja; Chrzanowski, Lukasz; Bogacki, Mariusz [Poznan Univ. of Technology (Poland). Inst. of Chemical Technology and Engineering; Cyplik, Pawel; Olejnik-Schmidt, Agniezka K. [Poznan Univ. of Life Sciences (Poland). Dept. of Biotechnology and Food Microbiology; Heipieper, Hermann J. [Helmholtz Centre for Environmental Research - UFZ, Leipzig (Germany). Dept. of Environmental Biotechnology

    2009-09-15

    In this study, we elucidated the role of cell surface hydrophobicity (microbial adhesion to hydrocarbons method, MATH) and the effect of anionic rhamnolipids and nonionic Triton X-100 surfactants on biodegradation of diesel fuel employing 218 microbial consortia isolated from petroleum-contaminated soils. Applied enrichment procedure with floating diesel fuel as a sole carbon source in liquid cultures resulted in consortia of varying biodegradation potential and diametrically different cell surface properties, suggesting that cell surface hydrophobicity is a conserved parameter. Surprisingly, no correlations between cell surface hydrophobicity and biodegradation of diesel fuel were found. Nevertheless, both surfactants altered cell surface hydrophobicity of the consortia in similar manner: increased for the hydrophilic and decreased for the hydrophobic cultures. In addition to this, the surfactants exhibited similar influence on diesel fuel biodegradation: Increase was observed for initially slow-degrading cultures and the opposite for fast degraders. This indicates that in the surfactant-mediated biodegradation, effectiveness of surfactants depends on the specification of microorganisms and not on the type of surfactant. In contrary to what was previously reported for pure strains, cell surface hydrophobicity, as determined by MATH, is not a good descriptor of biodegrading potential for mixed cultures. (orig.)

  5. Ice sheet hydrology from observations

    International Nuclear Information System (INIS)

    The hydrological systems of ice sheets are complex. Our view of the system is split, largely due to the complexity of observing the systems. Our basic knowledge of processes have been obtained from smaller glaciers and although applicable in general to the larger scales of the ice sheets, ice sheets contain features not observable on smaller glaciers due to their size. The generation of water on the ice sheet surface is well understood and can be satisfactorily modeled. The routing of water from the surface down through the ice is not complicated in terms of procat has been problematic is the way in which the couplings between surface and bed has been accomplished through a kilometer of cold ice, but with the studies on crack propagation and lake drainage on Greenland we are beginning to understand also this process and we know water can be routed through thick cold ice. Water generation at the bed is also well understood but the main problem preventing realistic estimates of water generation is lack of detailed information about geothermal heat fluxes and their geographical distribution beneath the ice. Although some average value for geothermal heat flux may suffice, for many purposes it is important that such values are not applied to sub-regions of significantly higher fluxes. Water generated by geothermal heat constitutes a constant supply and will likely maintain a steady system beneath the ice sheet. Such a system may include subglacial lakes as steady features and reconfiguration of the system is tied to time scales on which the ice sheet geometry changes so as to change pressure gradients in the basal system itself. Large scale re-organization of subglacial drainage systems have been observed beneath ice streams. The stability of an entirely subglacially fed drainage system may hence be perturbed by rapid ice flow. In the case of Antarctic ice streams where such behavior has been observed, the ice streams are underlain by deformable sediments. It is

  6. Ice sheet hydrology from observations

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Peter (Dept. of Physical Geography and Quaternary Geology, Stockholm Univ-, Stockholm (Sweden))

    2010-11-15

    The hydrological systems of ice sheets are complex. Our view of the system is split, largely due to the complexity of observing the systems. Our basic knowledge of processes have been obtained from smaller glaciers and although applicable in general to the larger scales of the ice sheets, ice sheets contain features not observable on smaller glaciers due to their size. The generation of water on the ice sheet surface is well understood and can be satisfactorily modeled. The routing of water from the surface down through the ice is not complicated in terms of procat has been problematic is the way in which the couplings between surface and bed has been accomplished through a kilometer of cold ice, but with the studies on crack propagation and lake drainage on Greenland we are beginning to understand also this process and we know water can be routed through thick cold ice. Water generation at the bed is also well understood but the main problem preventing realistic estimates of water generation is lack of detailed information about geothermal heat fluxes and their geographical distribution beneath the ice. Although some average value for geothermal heat flux may suffice, for many purposes it is important that such values are not applied to sub-regions of significantly higher fluxes. Water generated by geothermal heat constitutes a constant supply and will likely maintain a steady system beneath the ice sheet. Such a system may include subglacial lakes as steady features and reconfiguration of the system is tied to time scales on which the ice sheet geometry changes so as to change pressure gradients in the basal system itself. Large scale re-organization of subglacial drainage systems have been observed beneath ice streams. The stability of an entirely subglacially fed drainage system may hence be perturbed by rapid ice flow. In the case of Antarctic ice streams where such behavior has been observed, the ice streams are underlain by deformable sediments. It is

  7. Stability of Dirac sheet configurations

    International Nuclear Information System (INIS)

    Using cooling for SU(2) lattice configurations, purely Abelian constant magnetic-field configurations were left over after the annihilation of constituents that formed metastable Q=0 configurations. These so-called Dirac sheet configurations were found to be stable if emerging from the confined phase, close to the deconfinement phase transition, provided their Polyakov loop was sufficiently nontrivial. Here we show how this is related to the notion of marginal stability of the appropriate constant magnetic-field configurations. We find a perfect agreement between the analytic prediction for the dependence of stability on the value of the Polyakov loop (the holonomy) in a finite volume and the numerical results studied on a finite lattice in the context of the Dirac sheet configurations

  8. Electromagnetic instability in a magnetic neutral sheet

    International Nuclear Information System (INIS)

    The structure of electromagnetic perturbations in a magnetic neutral sheet was analyzed within the framework of a Vlasov-Maxwellian picture. In the geomagnetic tail, there exists a stable magnetic neutral sheet of about 10 R-E (earth radius) thick. However, it has been reported that the thickness of this sheet is reduced to about 1 R-E just before the onset of substorms, and this shows the critical thickness of sheet destruction. In the laboratory experiment, a stable neutral sheet is produced by induction, and its thickness also becomes as thin as about the ion Larmor radius, which is defined far outside the sheet region, before the sudden destruction of the sheet current. Tearing instability cannot explain this abrupt destruction. Then it can be considered that the tearing instability is stabilized by some mechanisms. Consequently, it becomes important to look for another perturbation unstable in a thin sheet while stable in a thick sheet. Here, a magnetically compressional mode propagating in the direction of the unperturbed current which produced reverse field is considered. Equilibrium configuration and particle orbits, perturbations, resulted eigenfunctions and dispersion relations are described to show that the above mode becomes unstable in a thin sheet, and the critical thickness is about the ion Larmor radius just outside the sheet region. When the typical field intensity in the geomagnetic tail is taken, the time scale of this instability becomes about 800 sec. This value coincides with the observed flare time scale. (Wakatsuki, Y.)

  9. Ice Sheets and the Anthropocene

    OpenAIRE

    Wolff, Eric W.

    2014-01-01

    Ice could play a role in identifying and defining the Anthropocene. The recurrence of northern hemisphere glaciation and the stability of the Greenland Ice Sheet are both potentially vulnerable to human impact on the environment. However, only a very long hiatus in either would be unusual in the context of the Quaternary Period, requiring the definition of a geological boundary. Human influence can clearly be discerned in several ice-core measurements. These include a sharp boundary in radioa...

  10. Strontium-90 fluoride data sheet

    International Nuclear Information System (INIS)

    This report is a compilation of available data and appropriate literature references on the properties of strontium-90 fluoride and nonradioactive strontium fluoride. The objective of the document is to compile in a single source pertinent data to assist potential users in the development, licensing, and use of 90SrF2-fueled radioisotope heat sources for terrestrial power conversion and thermal applications. The report is an update of the Strontium-90 Fluoride Data Sheet (BNWL-2284) originally issued in April 1977

  11. Technology to Market Fact Sheet

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-02-01

    This fact sheet is an overview of the Technology to Market subprogram at the U.S. Department of Energy SunShot Initiative. The SunShot Initiative’s Technology to Market subprogram builds on SunShot’s record of moving groundbreaking and early-stage technologies and business models through developmental phases to commercialization. Technology to Market targets two known funding gaps: those that occur at the prototype commercialization stage and those at the commercial scale-up stage.

  12. Growth responses of Kentucky-31, Kenhy, and Kenwell tall fescues established under differing rates of wood fiber and hardwood bark mulches on eastern Kentucky surface mines

    Energy Technology Data Exchange (ETDEWEB)

    Koon, D.L.; Graves, D.H.

    1980-12-01

    In August, 1977 Kentucky-31, Kenwell, and the newly released Kenhy variety of tall fescue (Festuca arundinacea (L.) Schreb.) were planted on Falcon Coal Company land in eastern Kentucky to evaluate their establishment and vegetative responses to wood fiber mulch (WFM) and hardwood tree bark. Each of the one-half acre plots were fertilized at a constant rate of four hundred (400) pounds of 16-32-8 fertilizer and seeded at the rate of twenty (20) pounds and four (4) pounds per acre with a tall fescue variety and sweet clover (Melilotus officinalis (L.) Lam.) respectively. Plot mulch treatments included a control, 35 and 70 cubic yards per acre of hardwood bark, and 300 and 750 pounds per acre of WFM. Percent total ground cover and percent cover occupied by grasses and by legumes were collected for two growing seasons. Reduced seeding rates were utilized to increase the length of time for establishment so that each variety could be easily compared over several growing seasons, indicating adaptability for establishment on eastern Kentucky mine spoil.

  13. Effect of Different Norms of Under-Mulch-Drip Irrigation on Diurnal Changes of Photosynthesis and Chlorophyll Fluorescence Parameter in High Yield Cotton of Xinjiang

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wang-feng; REN Li-tong; WANG Zhen-lin; LI Shao-kun; GOU Ling; YU Songlie; CAO Lian-pu

    2003-01-01

    Under-mulch-drip irrigation is an advanced irrigation technique, which combines plastic-film-covered cultivation with drip irrigation. The influence of different norms of under-mulch-drip irrigation on di-urnal changes of photosynthetic rates and chlorophyll fluorescence parameters of cotton was studied, in orderto understand the physiological mechanisms of water-saving and high-yielding farming in Xinjiang. Results in-dicated that limited drip irrigation, which supplies 2/3 of 375 m3 ha-1 , the widely-used irrigation norm in cot-ton cultivation in Xinjiang, caused a water deficit in cotton field. Compared with the proper drip irrigation,the leaf photosynthetic rate under limited drip irrigation decreased during 9:00 to 11:00 a. m., and was sig-nificantly suppressed at midday, and then recovered afterwards. Using the chlorophyll fluorescence method,the absorption, transfer and transformation features of solar radiation by cotton leaf were investigated. Underlimited drip irrigation, the variable fluorescence (Fy) and primary light transfer efficiency of PSII (Fv/Fm)in cotton leaves were reduced because of the high light intensities and high temperatures at noon, and the de-crease in Xinluzao8 was greater than that in Xinluzao6. Therefore, it could be concluded that Xinluzao6 has ahigher drought-tolerance, and the Fv/Fm ratio could be used as a drought-resistance index for cotton.

  14. Reconnection in thin current sheets

    Science.gov (United States)

    Tenerani, Anna; Velli, Marco; Pucci, Fulvia; Rappazzo, A. F.

    2016-05-01

    It has been widely believed that reconnection is the underlying mechanism of many explosive processes observed both in nature and laboratory, but the question of reconnection speed and initial trigger have remained mysterious. How is fast magnetic energy release triggered in high Lundquist (S) and Reynolds (R) number plasmas?It has been shown that a tearing mode instability can grow on an ideal timescale, i.e., independent from the the Lundquist number, once the current sheet thickness becomes thin enough, or rather the inverse aspect ratio a/L reaches a scale a/L~S-1/3. As such, the latter provides a natural, critical threshold for current sheets that can be formed in nature before they disrupt in a few Alfvén time units. Here we discuss the transition to fast reconnection extended to simple viscous and kinetic models and we propose a possible scenario for the transition to explosive reconnection in high-Lundquist number plasmas, that we support with fully nonlinear numerical MHD simulations of a collapsing current sheet.

  15. Biodegradability enhancement of municipal landfill leachate

    Directory of Open Access Journals (Sweden)

    Pi Kewu

    2008-12-01

    Full Text Available The method of enhancing the biodegradability of landfill leachate via air stripping followed by coagulation/ultrafiltration (UF processes is introduced. In this study, the air stripping process obtained a removal efficiency of 88.6% for ammonia nitrogen (NH3-N, at an air-to-liquid ratio (A/L of 3 300 (pH = 11 and after 18 h of stripping. The single coagulation process increased the BOD (biological oxygen demand/COD (chemical oxygen demand ratio by 0.089 with a FeCl3 dosage of 570 mg/L, at pH 7.0, and the single UF process increased the BOD/COD ratio from 0.049 to 0.311. However, the combination of coagulation and UF increased the BOD/COD ratio from 0.049 to 0.423, and the final BOD, COD, NH3-N, and colour of the leachate were 1 023 mg/L, 2 845 mg/L, 145 mg/L, and 2 056, respectively, when a 3 kDa molecular weight cut-off (MWCO membrane was used at an operating pressure of 0.7 MPa. In the ultrafiltration process, the average solution flux (JV, concentration multiple (MC, and retention rate (R for the COD were 107.3 L/(m2·h, 6.3, and 84.2%, respectively.

  16. Microbial ecology of bacterially mediated PCB biodegradation

    International Nuclear Information System (INIS)

    The roles of plasmid mediated and consortia mediated polychlorinated biphenyl (PCB) biodegradation by bacterial populations isolated from PCB contaminated freshwater sediments were investigated. PCB degrading bacteria were isolated by DNA:DNA colony hybridization, batch enrichments, and chemostat enrichment. Analysis of substrate removal and metabolite production were done using chlorinated biphenyl spray plates, reverse phase high pressure liquid chromatography, Cl- detection, and 14C-labeled substrate mineralization methods. A bacterial consortium, designated LPS10, involved in a concerted metabolic attack on chlorinated biphenyls, was shown to mineralize 4-chlorobiphenyl (4CB) and 4,4'-dichlorobiphenyl (4,4' CB). The LPS10 consortium was isolated by both batch and chemostat enrichment using 4CB and biphenyl (BP) as sole carbon source and was found to have tree bacterial isolates that predominated; these included: Pseudomonas, testosteroni LPS10A which mediated the breakdown of 4CB and 4,4' CB to the putative meta-cleavage product and subsequently to 4-chlorobenzoic acid (4CBA), an isolate tentatively identified as an Arthrobacter sp. LPS10B which mediated 4CBA degradation, and Pseudomonas putida by A LPS10C whose role in the consortium has not been determined

  17. Equilibrium gold nanoclusters quenched with biodegradable polymers.

    Science.gov (United States)

    Murthy, Avinash K; Stover, Robert J; Borwankar, Ameya U; Nie, Golay D; Gourisankar, Sai; Truskett, Thomas M; Sokolov, Konstantin V; Johnston, Keith P

    2013-01-22

    Although sub-100 nm nanoclusters of metal nanoparticles are of interest in many fields including biomedical imaging, sensors, and catalysis, it has been challenging to control their morphologies and chemical properties. Herein, a new concept is presented to assemble equilibrium Au nanoclusters of controlled size by tuning the colloidal interactions with a polymeric stabilizer, PLA(1k)-b-PEG(10k)-b-PLA(1k). The nanoclusters form upon mixing a dispersion of ~5 nm Au nanospheres with a polymer solution followed by partial solvent evaporation. A weakly adsorbed polymer quenches the equilibrium nanocluster size and provides steric stabilization. Nanocluster size is tuned from ~20 to ~40 nm by experimentally varying the final Au nanoparticle concentration and the polymer/Au ratio, along with the charge on the initial Au nanoparticle surface. Upon biodegradation of the quencher, the nanoclusters reversibly and fully dissociate to individual ~5 nm primary particles. Equilibrium cluster size is predicted semiquantitatively with a free energy model that balances short-ranged depletion and van der Waals attractions with longer-ranged electrostatic repulsion, as a function of the Au and polymer concentrations. The close spacings of the Au nanoparticles in the clusters produce strong NIR extinction over a broad range of wavelengths from 650 to 900 nm, which is of practical interest in biomedical imaging. PMID:23230905

  18. Microporous biodegradable polyurethane membranes for tissue engineering.

    Science.gov (United States)

    Tsui, Yuen Kee; Gogolewski, Sylwester

    2009-08-01

    Microporous membranes with controlled pore size and structure were produced from biodegradable polyurethane based on aliphatic diisocyanate, poly(epsilon-caprolactone) diol and isosorbide chain extender using the modified phase-inversion technique. The following parameters affecting the process of membrane formation were investigated: the type of solvent, solvent-nonsolvent ratio, polymer concentration in solution, polymer solidification time, and the thickness of the polymer solution layer cast on a substrate. The experimental systems evaluated were polymer-N,N-dimethylformamide-water, polymer-N,N-dimethylacetamide-water and polymer-dimethylsulfoxide-water. From all three systems evaluated the best results were obtained for the system polymer-N,N-dimethylformamide-water. The optimal conditions for the preparation of microporous polyurethane membranes were: polymer concentration in solution 5% (w/v), the amount of nonsolvent 10% (v/v), the cast temperature 23 degrees C, and polymer solidification time in the range of 24-48 h depending on the thickness of the cast polymer solution layer. Membranes obtained under these conditions had interconnected pores, well defined pore size and structure, good water permeability and satisfactory mechanical properties to allow for suturing. Potential applications of these membranes are skin wound cover and, in combination with autogenous chondrocytes, as an "artificial periosteum" in the treatment of articular cartilage defects. PMID:19301104

  19. Kinetics of dimethoate biodegradation in bacterial system

    Directory of Open Access Journals (Sweden)

    Manisha DebMandal

    2011-11-01

    Full Text Available The present study is an investigation on the kinetics of dimethoate biodegradation and an estimation of residual dimethoate in bacterial culture by spectrophotometry. The methylene chloride extract of the culture medium was used for determination of dimethoate through its reaction with 1 chloro-2, 4 dinitrobenzene to produce methylamine whose absorbance at 505 nm gave an estimation of dimethoate content. The dimethoate standard curve follows Beer’s law at 505 nm with a slope of 0.0129 absorbance units per µg/mL. The regression equation relating concentration of dimethoate (x with the absorbance is (y: y = 0.037 + 0.0129x. The amount of residual dimethoate after 7 days were 0, 4, 17, 28 and 29 µg/mL; the rate constants were 0.775, 0.305, 0.225, 0.167 and 0.127 each per day, and the efficiency of dimethoate degradation were 100%, 96%, 83%, 72% and 71%, for Bacillus licheniformis, Pseudomonas aeruginosa, Aeromonas hydrophila, Proteus mirabilis and Bacillus pumilus respectively. Dimethoate remediation could be attained through bacterial metabolism of the pesticide and colorimetric analysis might be useful in the estimation of dimethoate within a detection limit of 5-100 µg/mL.

  20. Biodegradability enhancement of municipal landfill leachate

    Institute of Scientific and Technical Information of China (English)

    Pi Kewu; Gong Wenqi

    2008-01-01

    The method of enhancing the biodegradability of landfill leachate via air stripping followed by coagulation/ultrafiltration (UF) processes is introduced. In this study, the air stripping process obtained a removal efficiency of 88.6% for ammonia nitrogen (NH3-N), at an air-to-liquid ratio (A/L) of 3 300 (pH=11) and after 18 h of stripping. The single coagulation process increased the BOD (biological oxygen demand)/COD (chemical oxygen demand) ratio by 0.089 with a FeCl3 dosage of 570 mg/L, at pH 7.0, and the single UF process increased the BOD/COD ratio from 0.049 to 0.311. However, the combination of coagulation and UF increased the BOD/COD ratio from 0.049 to 0.423, and the final BOD, COD, NH3-N, and colour of the leachate were 1 023 mg/L, 2 845 mg/L, 145 mg/L, and 2 056, respectively, when a 3 kDa molecular weight cut-off (MWCO) membrane was used at an operating pressure of 0.7 MPa. In the ultrafiltration process, the average solution flux (JⅤ), concentration multiple (MC), and retention rate (R) for the COD were 107.3 L/(m2.h), 6.3, and 84.2%, respectively.