Abstract – In this report, time-dependent carrier concentration in electrolytic cells, due to some basic periodic shapes of excitation signal, has been studied. Exact analytical solutions for step, sinusoidal and periodic pulse reverse inputs are derived. The effect of frequency, forward and reverse amplitudes, and duty cycle are investigated. An analytical solution of the model is obtained as ...

the increasing use of nitrogen fertilizers due to high dynamics of nitrate in the soil would be a serious threat to groundwater, and therefore, to thuman health. this study is aimed to investigate the disperdivity values of nitrate in the coarse, medium and fine sandy soils in the short travel distance of 20, 40 and 80 cm in vitro using the hydrus-1d model. for this purpose, pure potassium nitr...

Electrolytic manganese dioxide (EMD) was prepared by using gas diffusion electrode (GDE) instead of traditional hydrogen evolution cathode. Sulfate acid’s effects on the cell voltage, the current efficiency, the electro-catalytic activity and the lifetime of GDE are studied. The results show that as the concentration of sulfuric acid increases, the current efficiency increases, while the cell v...

Growing rice on arsenic (As)-contaminated paddy fields may induce high As level grain production. In order to reduce the food contamination risk, the pot experiments containing two As-spiked aging soils and four water managements were conducted to evaluate the effects of water managements on rice As content. The results indicated that As concentration of Erlin soil solution was 10 to 20 times (...

Plants absorb nutrients needed for plant type, growing season, depending on soil and yield. Absorb of nutrient 30-90 percent depends management practices in the use of fertilizer. Can be used fertilizers in most cases soil and for foliar feeding can be quickly absorbed into the plant at the proper levels of nutrition in cucumber. In this experiment, was used a split plot in a randomized complet...

this research was conducted at the department of horticluture, university of tehran during years 2005-2006, to investigate the use of iran apatite rocks in zeoponic substrate and as well to evaluate them as substitutes for phosphate fertilizers. five different substrates namely: m1: 89 wt. % soil+10 wt. % zeolite + 1 wt.% jeyrood apatite; m2: 82 wt.% soil + 15 wt.% zeolite+ 3 wt. % jeyrood apat...