A new route to MFI/MCM-41 micro-mesoporous composite

A new route to MFI/MCM-41 micro-mesoporous composite is reported. This composite was synthesized for the first time by the hydrothermal microwave two-template method, and the stage of crystallization was carried out for the first time at 190°C. The developed procedure makes it possible to significantly reduce the time of synthesis of the MFI/MCM-41 micro-mesoporous composite as compared with the known methods.     

Micro-mesoporous composite MFI/MCM-41 as a new catalyst for producing liquid hydrocarbons by isobutanol conversion

The results of isobutanol conversion on micro-mesoporous composite MFI/MCM-41 synthesized using microwave irradiation were reported. It was shown that, unlike other described isobutanol conversion catalysts, this catalyst makes it possible to produce a hydrocarbon product containing a significant amount of aromatic hydrocarbons at low benzene content and also to avoid the undesirable formation of oxygen-containing products.     

Hydrogenation of oxygen-containing heterocyclic compounds on group VIII metals

The hydrogenation of a number of oxygen-containing heterocyclic compounds on Pt, Pd, and Rh blacks in the liquid phase at atmospheric pressure was investigated. The results are compared with data on H-D exchange with D₂O and are interpreted from the point of view of the theory of -complex adsorption.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No.10, pp. 1332–1334, October, 1981.     

Product range,properties, and application of fluoropolymers manufactured in Kirovo-Chepetsk Chemical Industrial Complex

The main historical stages of development in the USSR of industrial production of fluoroplastics and organofluorine materials are outlined. Physical, chemical and biological properties of fluoroplastics and fluoroelastomers are described. Examples of efficient application of fluoropolymers in chemical and natural gas industry, power production, and medicine are cited. The review is intended for specialists in fluoropolymers application.     

Kinetic simulation of the oxidative condensation of methane

The kinetics of the oxidative condensation of methane (OCM) over a mixed-oxide lithium-manganese-tungsten-silicate catalyst has been simulated, and systems of stoichiometric chemical equations possible under the OCM conditions have thereby been discriminated. A phenomenological kinetic model has been developed to fit the observed rates of formation and disappearance of the compounds involved in OCM.     

Quantifying uncertainty in the measurement of arsenic in suspended particulate matter by Atomic Absorption Spectrometry with hydride generator

Arsenic is the toxic element, which creates several problems in human being specially when inhaled through air. So the accurate and precise measurement of arsenic in suspended particulate matter (SPM) is of prime importance as it gives information about the level of toxicity in the environment, and preventive measures could be taken in the effective areas. Quality assurance is equally important in the measurement of arsenic in SPM samples before making any decision. The quality and reliability of the data of such volatile elements depends upon the measurement of uncertainty of each step involved from sampling to analysis. The analytical results quantifying uncertainty gives a measure of the confidence level of the concerned laboratory. So the main objective of this study was to determine arsenic content in SPM samples with uncertainty budget and to find out various potential sources of uncertainty, which affects the results. Keeping these facts, we have selected seven diverse sites of Delhi (National Capital of India) for quantification of arsenic content in SPM samples with uncertainty budget following sampling by HVS to analysis by Atomic Absorption Spectrometer-Hydride Generator (AAS-HG). In the measurement of arsenic in SPM samples so many steps are involved from sampling to final result and we have considered various potential sources of uncertainties. The calculation of uncertainty is based on ISO/IEC17025: 2005 document and EURACHEM guideline. It has been found that the final results mostly depend on the uncertainty in measurement mainly due to repeatability, final volume prepared for analysis, weighing balance and sampling by HVS. After the analysis of data of seven diverse sites of Delhi, it has been concluded that during the period from 31^st Jan. 2008 to 7^th Feb. 2008 the arsenic concentration varies from 1.44 ± 0.25 to 5.58 ± 0.55 ng/m³ with 95% confidence level (k = 2).     

Diffuse reflectance spectra of aluminum oxide micropowders,modified powders,and nanopowders and their changes upon electron irradiation

Comparative analysis of the diffuse reflectance spectra (300–2100 nm) and of the integrated absorption factor of coatings based on micropowders, nanopowders, and micropowders modified with Al₂O₃ nanopowders has been performed. In addition, the changes in the spectra resulting from electron irradiation of the powders with energies of 30 keV at a fluence of up to 3∙16 cm^–2 have been analyzed. It has been found that the diffuse reflectance decreases in order of coatings based on micro-powders, nano-powders and modified powders, while radiation resistance increases in order of coatings based on nano-powders, modified and micropowders.