Thermodynamic properties of Cu<Subscript>5</Subscript>SmSe<Subscript>4</Subscript>

The heat capacity of Cu₅SmSe₄ has been measured from 80 to 300 K. The results have been used to assess the main thermodynamic functions of Cu₅SmSe₄: entropy (S ⁰(T) − S ⁰(0)), enthalpy increment (H ⁰(T) − H ⁰(0)), and reduced Gibbs energy (Φ⁰(T)).     

Phase composition changes in quartzitic waste from grain processing in relation to firing temperature

Translated from Steklo i Keramika, No. 7, pp. 22–23, July, 1991.     

Diagnosis of Well Production Operations on the Basis of Nonparametric Criteria of Production Data Variations

Abstract

The relevance of application of different parametric indices of time series variations, such as variance, variation coefficient, normalized deviation, Theil's criteria, etc., for assessment of technological processes is analyzed in this work.

Different nonparametric criteria of time series variations are suggested that allow diagnosis of changes in the conditions of the process analyzed, when application of other criteria are incorrect or inappropriate.

The applicability and simplicity of realization of nonparametric criteria for practical engineering calculations in analysis of multifractal and chaotic fluctuations are shown.

The applicability of the suggested criteria of time series variations for early diagnosis of qualitative changes in behavior of dynamic systems is proven on model examples as well as on practical examples of oil and gas production.     

Oxidative desulfurization of catalytically cracked gasolines produced from blended Baku oils

Oxidative desulfurization of catalytically cracked gasolines, produced from a blend of Baku crude oils, with hydrogen peroxide in a formic acid medium under phase-transfer catalysis conditions using pyridine and acetonitrile as ligands has been studied. It has been found that running the process under these conditions on heterogeneous catalysts containing Mo and Co ions makes it possible to decrease the residual sulfur content in the gasolines from 200 to 33–40 ppm.     

Highly effective ironporphyrin-immobilized catalytic systems for the processes of hydroxylation and epoxidation of lower alkanes and alkenes

The catalytic activity of the following samples in the hydroxylation reaction were studied: PPFe 3+ OH/AlSiCr, PPFe 3+ OH/AlSiMg, PPFe 3+ OH/Al 2 O 3 , and per-FTPhPFe 3+ OH/Al 2 O 3 . PPFe 3+ OH/AlSiMg-catalyzed methane hydroxylation yielded 46.5 wt% of methanol at a 48% methane conversion, at a maximum of 180°C. Per-FTPhPFe 3+ OH/Al 2 O 3 testing in propane hydroxylation by H 2 O 2 yielded 39.3 mol% of isopropanol. Per-FTPhPFe 3+ OH/Al 2 O 3 -catalyzed propylene oxidation by H 2 O 2 yielded 30 mol% of propylene oxide. PPFe 3+ OH/Al 2 O 3 -catalyzed propylene epoxidation yielded the following: the selectivity on the monooxygenase products is about 100%, the selectivity on propylene oxide - 59.2%, propylene conversion - 93.3%. The experimental research data revealed the fact that during the reaction of epoxidation per-FTPhPFe 3+ OH/Al 2 O 3 proved to be more stable under the influence of oxidizer and temperature than PPFe 3+ OH/Al 2 O 3 .