density functional theory (dft) calculations have been performed to investigating the effects of themolecular oxygen impurity on the quadrupole coupling constant (qcc) parameters of armchair and zigzagboron nitride nanotubes (bnnts). optimization processes have been performed to relax the original andimpure structures of the investigated bnnts. afterwards, the qcc parameters have been evaluated...

Time-resolved spectroscopy is employed to analyze micro plasma generated in laboratory air. Stark-broadened emission profiles for hydrogen alpha and beta allow us to determine plasma characteristics for specific time delays after plasma generation. Stark shift, asymmetry, and full width half maximum measurements are used to infer electron density. The measurements of hydrogen alpha and beta Bal...

This study was designed to investigate the effects of different tillage systems on some parameters such as soil salinity (pH, EC, SAR), soil density and nutrients in a nested experimental design with three treatments (no tillage, reduced tillage and conventional tillage) and three replications. Chenaran city fields were selected as the case study areas. Result of the statistical analysis indica...

sterilized soils are commonly used for the study of xenobiotic sorption and as an abiotic control in biodegradation experiments. they are also used for the chemical study of nitrogen and carbon cycle processes and the elimination of the biological factors. in this research the effects of different soil sterilization methods such as autoclaving, fumigating and exposure to ultraviolet and microwa...

Plant photosynthate fuels carbon-limited microbial growth and activity, resulting in increased rhizosphere nitrogen (N) mineralization. Most soil organic nitrogen is macromolecular (chitin, protein, nucleotides); enzymatic depolymerization is likely rate limiting for plant nitrogen accumulation. Analyzing Avena (wild oat) planted in microcosms containing sieved field soil, we observed increased...

The field study was conducted in one district of Educational-Experimental forest at Tehran University (Kheirood-Kenar forest) in the North of Iran. Eighty-five soil profiles were dug in the site of study and several chemical and physical soil properties were considered. These factors included: soil pH, soil texture, bulk density, organic carbon, total nitrogen, extractable phosphorus and depth ...

In terms of tillering potential, the aboveground portions of rice are significantly influenced by the nitrogen level (NL) and transplant density (TD). To obtain a suitable combination of NL and TD, five NLs (0, 90, 180, 270 and 360 kg ha-1) and two TDs [high density (HD), 32.5×104 hills ha-1; low density (LD), 25.5×104 hills ha-1] were used in the rice experiments during 2012 to 2014, in Jiangs...

irrigation management, soil tillage method and fertilizer management play important roles in increasing crop yield and water and solute movement in the soil profile. the present research was conducted to study the effects of a no-tillage system and nitrogen fertilizer on the mineral nitrogen movement and soil moisture under optimum irrigation conditions. the study was conducted at safiabad agri...