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A proposed modification of the dinamic subgrid scale closure method  [PDF]
A. Costa
Physics , 2011,
Abstract: A proposed modification of the dinamic subgrid scale closure method for LES.
Desnitrificación de un fertilizante de lenta liberación y urea+fosfato monoamónico aplicados a trigo irrigado con agua residual o de pozo
MORA RAVELO, Sandra Grisell;GAVI REYES, Francisco;PE?A CABRIALES, Juan José;PERéZ MORENO, Jesús;TIJERINA CHáVEZ, Leonardo;VAQUERA HUERTA, Humberto;
Revista internacional de contaminación ambiental , 2007,
Abstract: the study of n2o emission originated by the combination of different types of fertilizers and water on rizospheric soil, and non- rizospheric soil along the crop cycle, can contribute to useful knowledge in order to increase fertilizer and manure n recovery efficiency and to reduce the n loss by denitrification. the efficient use of nitrogen fertilizers and non- treated urban waste water for crops is an agronomic, economic and environmental need. the denitrification is an important factor that diminishes the n efficiency in crops. the objective of this investigation was to evaluate the denitrification of a slow release fertilizer using as reference urea plus monoamonium phosphate and an organic fertilizer, applied to wheat irrigated with urban waste water or well water. analyses were made in the vertisol type soil used in the experiment with both, rizospheric and non-rizospheric soil. the slow release fertilizer used has a matrix enriched with n and p and its patent is currently in progress. each fertilizer was evaluated alone, as well as the slow release fertilizer plus organic fertilizer. the samples of rhizospheric and non-rhizospheric soils for each treatment were collected at 55, 67 and 97 days after sowing and incubated during 18 days at 25 °c, controlling the soil humidity daily. the results (p < 0.05) showed that the interactions between samplings and types of water, samplings and fertilizers, and types of water and fertilizers affected (p < 0.06) the emission of n2o, which was increased when urea plus monoamonium phosphate and waste water were applied. on average, there was less n2o when emissions slow release fertilizer or organic fertilizer were applied and irrigated with well water as compared to irrigation with waste water. as well, use of waste water was, on average, associated with a bigger loss of n. the highest average emission in n2o was observed 67 days after sowing. the average denitrification was similar in the rhizospheric and non-rhizospheric
Instructional Transaction Theory and a New Dinamic Aproach to CAI Design
Murat Pasa UYSAL
Journal of Kirsehir Education Faculty , 2010,
Abstract: Designing and developing Computer Aided Insructional (CAI) softwares requires timeconsuming and labor-intensive processes. One of the factors which determines the quality of these softwares is that they undergo appropriate design processes. The other factor is the their capabilities of response to the instructional needs during or after instruction. A suitable CAI design model involves adoption of an efficient and dinamic approach to the both instructional design and software develoment proceses. In this study, Both the design model Instructional Transaction Theory which is thought to be suited for the nature of CAI and the dinamic approach, brought to the CAI design in line with the Agile Software Development, are discussed.
Determinants of Wheat Productivity in Irrigated Balochistan  [PDF]
Nisar Ali Shah,S. Mohammad Khair,M. Afzal,Manzoor Ahmad Kasi
Asian Journal of Plant Sciences , 2002,
Abstract: The survey was conducted in two districts of irrigated Balochistan i.e., Nasirabad and Jaffarabad from 73 farmers. The farmers allocated over 46 % of their holdings to wheat production during 1999-2000. However, the area under wheat crop declined by 5.2 % during Rabi 1999-2000. Relatively greater reduction (13.1 %) in wheat acreage was recorded in Jaffarabad district than that in Nasirabad district. Both bassal and top dressing methods were used by the farmers. The farmers used fertilizer both at the time of sowing and with first irrigation mostly with N as a second dose, but the quantity far below the recommended 120-60-90 NPK. Late sowing and weed infestation was found as the second major cause of low yield. Lodging and rust contributed in yield loss due to using tall varieties which was found 1.3 and 1.3 % respectively in both the districts. Farmers used only 12.1 and 10 kg of N and P per acre as basal dressing during Rabi 1999-2000. The rate in Basal application was low, 10 kg N and P, while in top dressing the rate of N was high i.e., 15.7 kg but no phosphorus. As top dressing farmers in irrigated Balochistan were only applying N at the rate of 15.7 nut Kg per acre. Fertilizer rate was highest in Nasirabad for basal dressing as compared to Jaffarabad district using more fertilizer as top dressing. Irrigated Balochistan experienced a decline of 2.4 mounds acre -1 in its wheat yield during Rabi 1999-2000 on overall basis The yield in Jaffarabad district remained unchanged whereas Nasirabad district experienced inclines of 4 mounds acre -1 in wheat yield during the year 1999-2000 due to high rate of fertilizer.
Heavy metal content of alfalfa irrigated with waste and tubewell water
Mohammad Jamal Khan,Mohammad Tariq Jan,Dost Mohammad
Soil & Environment , 2011,
Abstract: A field experiment was conducted to study the effect of wastewater on yield and heavy metal uptake of alfalfa along with a tubewell irrigated crop as control at the Agricultural University Peshawar during 2009. The experiment was conducted in small plots (2 x 1m) replicated thrice with fertilizer additions. The crop was either irrigated with Hayatabad Industrial Estate (HIE) wastewater or tubewell water. The yield data revealed that shoot dry weight was significantly affected by the irrigation water supplies and higher yield was recorded in wastewater irrigated plots and the increase was consistent with time (different cutting). By comparing the total dry biomass of the two treatments, it was observed that there was about 37% increase in yield over control with application of wastewater. The shoot dry weight increased by a factor of about two to three times from first cutting to third cutting in both the treatment plots and the magnitude of increase in yield was higher in wastewater irrigated plots. The heavy metal uptake by the crop was much higher in wastewater irrigated plots compared to tubewell water. The order of metal uptake was Fe> Mn>Zn>Cu>Pb>Ni>Cr>Cd. Shoot analysis showed no metal toxicity because the concentration of the metal was less than phytotoxic level and all the metals were within the permissible limits.
Oxalate Content of Miner’s Lettuce Irrigated with Water or Fertilizer Solutions  [PDF]
Madhuri Kanala, Geoffrey P. Savage
Food and Nutrition Sciences (FNS) , 2016, DOI: 10.4236/fns.2016.713118
Abstract: The total, soluble and insoluble oxalate contents of the small, large and cauline leaves and small and large stems of miner’s lettuce (Claytonia perfoliata ) plants which had been irrigated with tap water or a soluble fertilizer were extracted and measured using HPLC chromatography. Overall, all plant parts of miner’s lettuce analyzed contained high levels of total and soluble oxalates; however plants irrigated with fertilizer contained lower levels of oxalates compared with plants irrigated with water. On a dry matter basis, the small leaves contained higher levels of total oxalate when compared to the total oxalate in the large leaves. Soluble oxalate in the leaves of plants irrigated with water ranged from 2.6 to 7.5 mg/100g dry matter (DM) and was significantly higher (P < 0.05) than the leaves of the fertilizer-watered plants, which ranged from 1.8 to 2.8 mg/100g DM. The soluble oxalate in the small and large stems of the fertilizer-watered plants ranged from 1.20 to 1.5 mg/100g DM and was significantly lower (P < 0.05) than the water-treated small and large stems, which ranged from 3.75 to 4.4 mg/100g DM. It is recommended that the leaves of miner’s lettuce should be consumed in moderation.
Evaluation of Biofertilizers in Irrigated Rice: Effects on Grain Yield at Different Fertilizer Rates  [PDF]
Ni?o Paul Meynard Banayo,Pompe C. Sta. Cruz,Edna A. Aguilar,Rodrigo B. Badayos,Stephan M. Haefele
Agriculture , 2012, DOI: 10.3390/agriculture2010073
Abstract: Biofertilizers are becoming increasingly popular in many countries and for many crops, but very few studies on their effect on grain yield have been conducted in rice. Therefore, we evaluated three different biofertilizers (based on Azospirillum, Trichoderma, or unidentified rhizobacteria) in the Philippines during four cropping seasons between 2009 and 2011, using four different fertilizer rates (100% of the recommended rate [RR], 50% RR, 25% RR, and no fertilizer as Control). The experiments were conducted under fully irrigated conditions in a typical lowland rice environment. Significant yield increases due to biofertilizer use were observed in all experimental seasons with the exception of the 2008/09 DS. However, the effect on rice grain yield varied between biofertilizers, seasons, and fertilizer treatments. In relative terms, the seasonal yield increase across fertilizer treatments was between 5% and 18% for the best biofertilizer ( Azospirillum-based), but went up to 24% in individual treatments. Absolute grain yield increases due to biofertilizer were usually below 0.5 t·ha ?1, corresponding to an estimated additional N uptake of less than 7.5 kg N ha ?1. The biofertilizer effect on yield did not significantly interact with the inorganic fertilizer rate used but the best effects on grain yield were achieved at low to medium fertilizer rates. Nevertheless, positive effects of the biofertilizers even occurred at grain yields up to 5 t·ha ?1. However, the trends in our results seem to indicate that biofertilizers might be most helpful in rainfed environments with limited inorganic fertilizer input. However, for use in these target environments, biofertilizers need to be evaluated under conditions with abiotic stresses typical of such systems such as drought, soil acidity, or low soil fertility.
DIFFERENTIAL SCANNING CALORIMETRY AND DINAMIC MECHANICAL ANALYSIS OF PHENOL-RESORCINOL-FORMALDEHYDE RESINS
LISPERGUER,JUSTO; DROGUETT,CYNTHIA; RUF,BEATRIZ; NU?EZ,MARIO;
Journal of the Chilean Chemical Society , 2005, DOI: 10.4067/S0717-97072005000200002
Abstract: differential scanning calorimetry ( dsc ) and dinamic mechanical analysis ( dma ) were use to study the curing reactions of two phenol - resorcinol- formaldehyde ( prf ) adhesives with 15 and 25 % resorcinol content, synthesized in laboratory. the prf resin with lower resorcinol content ( prf1 ) shows a double exothermic peak ( 99.9 and 158.2 °c ) while prf2 ,with greater resorcinol content ( 25 %) shows only one peak at 93.9 °c. the dma storage modulus e' confirm the differences in the curing behavior of prf adhesives. in the delamination resistance test during accelerated exposure only prf2 with a greater content of resorcinol, fulfilled the astm d 2559 requirements for beams treated with two cca retention levels. the cross-linking reactions was produced in the curing process at lower temperature in prf2 , enhanced the adhesion durability to glulams treated with cca preservatives
DIFFERENTIAL SCANNING CALORIMETRY AND DINAMIC MECHANICAL ANALYSIS OF PHENOL-RESORCINOL-FORMALDEHYDE RESINS  [cached]
JUSTO LISPERGUER,CYNTHIA DROGUETT,BEATRIZ RUF,MARIO NU?EZ
Journal of the Chilean Chemical Society , 2005,
Abstract: Differential scanning calorimetry ( DSC ) and dinamic mechanical analysis ( DMA ) were use to study the curing reactions of two phenol - resorcinol- formaldehyde ( PRF ) adhesives with 15 and 25 % resorcinol content, synthesized in laboratory. The PRF resin with lower resorcinol content ( PRF1 ) shows a double exothermic peak ( 99.9 and 158.2 °C ) while PRF2 ,with greater resorcinol content ( 25 %) shows only one peak at 93.9 °C. The DMA storage modulus E' confirm the differences in the curing behavior of PRF adhesives. In the delamination resistance test during accelerated exposure only PRF2 with a greater content of resorcinol, fulfilled the ASTM D 2559 requirements for beams treated with two CCA retention levels. The cross-linking reactions was produced in the curing process at lower temperature in PRF2 , enhanced the adhesion durability to glulams treated with CCA preservatives
Sewage Sludge as Nitrogen Source for Irrigated Silage Sorghum
Bilal Keskin,Ibrahim Hakki Yilmaz,Mehmet Ali Bozkurt,Hakki Akdeniz
Journal of Animal and Veterinary Advances , 2012,
Abstract: Field experiment was conducted in clay loam soil in Van, located in the eastern part of Turkey, to study sewage sludge and ammonium sulphate as nitrogen sources for sorghum. Silage and dry matter yield, plant height, stem, leaf and panicle ratio, plant nitrogen content, total N uptake, leaf nutrient and heavy metal content, soil DTPA-extractable nutrient and heavy metal content were quantified. The experimental design was a randomized complete block with four replications. Two rates of ammonium sulphate (50, 100 kg ha-1) and three rates of sewage sludge (5.95, 11.90 and 23.80 Mg ha-1) were applied to plots. Sorghum plant was irrigated once a week until soil water content reached to field capacity. Silage and dry matter yield, plant height and total N uptake increased with application of chemical N fertilizer and sewage sludge as compared to control. The yield results revealed that, 100 kg ha-1 nitrogen rate and 23.80 Mg ha-1 sewage sludge rate caused to produce almost the same amount of silage and dry matter yield. Leaf N, P, Ca, Mg, Fe and Mn content of sorghum increased with application of N fertilizer and sewage sludge. Mentioned nutrients in leaf were found pretty similar with application of 100 kg ha-1 N rate and 23.80 Mg ha-1 sludge rate. Besides, Potassium content of sorghum leaf was not affected by either treatment. Leaf Zn content increased with application of N fertilizer and sewage sludge and it reached the highest level at 23.80 Mg ha-1 sludge rate. Leaf Cu content increased only with application of sewage sludge. Also, Fe, Zn, Cu and Ni contents in experiment soil increased with application of sewage sludge and their levels reached to the highest at 23.80 Mg ha-1 sludge rate. None of heavy metal reached toxic level either in plant or in soil. Results indicated that sewage sludge, produced in Van region, could be used as a fertilizer nitrogen source for sorghum, without risks associated with toxic heavy metals.
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