The effect of impurities on quantum chemical parameters of single-walled nanotubes (SWNTs) was studied using density functional theory (DFT). The density of states (DOS), Fermi energy and thermodynamic energies of (5,5) carbon nanotubes were calculated in the presence of nitrogen impurity. It was found that this nanotube remains metallic after being doped with one nitrogen atom. The partial den...

Total Volatile Base Nitrogen (TVB-N) and Trimethylamine (TMA-N) contents of Vetki (Lates calcarifer) were investigated following Conway’s Microdiffusion technique at 4 hour interval in Fish Quality Control Laboratory, Fisheries Marine Resource Technology Discipline, Khulna University. Observed TVB-N TMA-N value did not vary significantly among different size classes. At fresh condition, content...

in order to investigate the effects of soil chemical characteristics on weed species diversity in eastern mashhad region wheat (triticum aestivum l.) fields, an investigation was held in the year 2009. wheat fields were classified based on the acreage from 3-5, 5-10 and higher than 10 ha. five random soil samples were taken using a 5 cm diameter auger from the soil of each experimental field an...

Nitrogen management practices have an effect on crop yields but they can also have a negative impact on the environment. Practices such as banding fertilizer and/or split-applying total nitrogen needs per acre offer a more efficient use of nitrogen by significantly reducing nitrate leaching potential. Heavy rains occurring when plants are small and nitrogen demands are low can also increase nit...

Nitrogen deposition has dramatically altered biodiversity and ecosystem functioning on the earth; however, its effects on soil bacterial community and the underlying mechanisms of these effects have not been thoroughly examined. Changes in ecosystems caused by nitrogen deposition have traditionally been attributed to increased nitrogen content. In fact, nitrogen deposition not only leads to inc...

The overarching goal of this study is to simulate subsurface N* (sensu, Gruber and Sarmiento, 1997; GS97) anomaly patterns in the North Atlantic Ocean and determine the basin wide rates of N2-fixation that are required to do so. We present results from a new Atlantic implementation of a coupled physical-biogeochemical model that includes an explicit, dynamic representation of N2-fixation with l...

to evaluate the effect of different levels of nitrogen fertilizer and municipal compost on the essential yeild of savory pot experiment in 2009 was carried out in the darab region. different doses of compost was in four levels, including: zero c0:, 10c1:, 20c2: and 30c3: tons per hectare and nitrogen fertilizer include: zero n0:, 30n1:, 60 n2: and 90n3: kg of pure nitrogen from urea per hectare...

abstract conservation tillage practices integrated with appropriate residue management is an efficient approach in sustainable agriculture to prevent the removal or burning of crop residues. two years field experiments were conducted to evaluate the effect of wheat residue management on yield, yield component and morphophysiological characteristics of corn. experimental design was split plot us...

this experiment was conducted to evaluate the effects of different sowing densities and nitrogen fertilizer rates on quantitative and qualitative corn forage yield in an agroforestry system with orange trees. the treatments consisted of 4 nitrogen fertilizer levels of 0, 100, 200, and 300kg n/ha (allocated to main plots) and 4 sowing densities of 80000, 110000, 140000 and 170000 of corn seeds (...