conclusions the mssrhs could be considered as a more suitable packing material for long-term biofilter operation to remove h2s pollution. results in this study, after 53 days of operating time and 54 g/m3h mass loading, the ph values in the ss and mssrhs packed filters were reduced from 6.8 to 1.8 and from 6.9 to 3.4, respectively. the mssrhs packed filter showed more buffering capacity to resi...

a theoretical density functional theory (dft) study was performed on a series of the neutral n-phenylthiourea substituents (p-oc2h5, p-ch3, m-ch3, h, p-cl, p-br, m-cl, and p-no2) as the sensor of acetate and fluoride anions. the hydrogen bond character was analyzed as a scale of the sensing activity. it was confirmed that hydrogen bond between the p-no2 derivatives of n-phenylthiourea and fluor...

conclusions the uv/zno system has been found an effective process with 90.2% cod removal and 95.6% dye removal after 50 minutes treatment. materials and methods in this work, zno catalyst and mercury lamp (uv-c, 254 nm) have been applied for removal of the c.i. sulphur red 14 dye from aqueous environments. the influence of various parameters such as the amount of zno, initial dye concentration,...

introduction: bleaching process can affect surface roughness of enamel, which is a vital factor in esthetic and resistance of tooth. the aim of this study was to compare surface roughness of enamel in teeth bleached using diode and neodymium-doped yttrium aluminium garnet (nd: yag) lasers with those bleached using conventional method. methods: in this study, 75 anterior human teeth from upper a...

In this study, the radial distribution and gravimetric storage capacities of hydrogen on coronene (C24H12) and its Si substituted forms, C24H12, C24-nSinH12 (n= 4-24), have been investigated at 298 K and 0.1 MPa (standard situation) using (N,V,T) Monte Carlo simulation by Lennard-Jones (LJ) 12-6 potential. The results show that the increase of number of silicon substitution doesn’t have any eff...

Abstract: Mg2Ni alloy and Mg2Ni–x wt% TiO2 (x = 3, 5 and 10 wt %) composites are prepared by mechanical alloying. The produced alloy and composites are characterized as the particles with nanocrystalline/amorphous structure. The effects of TiO2 on hydrogen storage properties are investigated using anodic polarization and electrochemical impedance spectroscopy. It is demonstrated that the initia...

In this study, the effect of the levels of hydrogen addition to methane-air premixed flame in a micro-stepped reactor has been studied numerically. In addition, the effects of mixture velocity and walls’ thermal conductivity (Kw) on the flame’s location, temperature, and species distribution in a micro reactor were calculated using a 2D numerical laminar steady code. The results ...

Proton exchange membrane fuel cells (PEMFCs) with a dead-ended anode and cathode can obtain high hydrogen and oxygen utilization by a comparatively simple system. Nevertheless, the accumulation of the water in the anode and cathode channels might cause a local fuel starvation degrading the performance and durability of PEMFCs. In this study, a brand new design for a polymer electrolyte membrane...

In the present study, a computational fluid dynamics (CFD) method have been utilized to investigate the effects of exhaust gas recirculation (EGR) and initial charge pressure by means of using a supercharger on the emissions and performance of a SI engine. This engine is fueled separately by gasoline and two potential alternative fuels, hydrogen and ethanol. The results of simulation are compar...