the purpose of this study is comparison of manganese absorption capacity by natural and modified zeolite. for this purpose used by from semnan mines zeolite with mean particle diameter of 360 micrometer. for modified zeolite, 5 g amount of natural zeolite with 100 ml of 1 m sodium chloride solution mixed and maintained at 24 hours in room temperature. for measure specific surface of absorbents,...

The single ion transport of transition metal ions like Cu(2+), Co(2+), Ni(2+) and Zn(2+) were carried out through the H(+) and alkali metal ion forms of Nafion membrane. These studies showed that the ion exchange selectivity coefficient of the permeating ion had an effect on its transport process. It was found that the diffusion coefficient values (D) were directly proportional to the selectivi...

Oxidation of ethylene to ethylene oxide over silver catalyst and selenium modified catalyst has been studied by continuous flow and pulse techniques over the temperature range of 230-280 °C. The results are discussed in terms of reaction mechanisms proposed by others, rejecting mechanisms which involve peroxide formation. It has been shown that not only selectivity towards ethylene oxide pr...

In present study, the two phase flow boiling heat transfer coefficient and pressure drop of R410A, R32 and R290 in microchannels are demonstrated. The experimental data were conducted in horizontal stainless steel tubes with the inner diameter of 0.3 mm and 1.5 mm. The testing conditions were performed with the mass fluxes range from 200 to 500 kg/m2s, the heat fluxes from 10 to 20 kW/m2, the s...

In this study, Mn (III) salen complex was synthesized and immobilized onto the graphene oxide, which is modified by 3-chloropropyltrimethoxy silane. Heterogeneous catalyst was characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, fourier transform infrared spectra, nitrogen adsorption−desorption isotherm and atomic absorption spectroscopy. The catalyt...

The application of membranes in various industries is one of the most urgent needs to reduce energy consumption and environmental pollutants as well as low investment costs in the process of separation. In this investigation, the optimization of effective parameters for separation of gas mixture of CH4, CO2, O2 and N2 is studied by modified poly(4-met...

A sensitive electrochemical sensor was fabricated for selective detection of nitric oxide (NO) based on electrochemically reduced graphene (ErGO)-polyaniline (PANI)-gold nanoparticles (AuNPs) nanocomposite. It was coated on a gold (Au) electrode through stepwise electrodeposition to form AuNPs-PANI-ErGO/Au electrode. The AuNPs-PANI-rGO nanocomposite was characterized by Field Emission Scanning ...