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Technologies of membrane-based gas separation can be integrated into existing industrial processes for low-temperature helium recovery from natural gas at the stages of crude helium separation from the N2/He mixture and its purification. The effectiveness of these processes is most affected by the properties of the materials from which the membrane is made. Due to their unique properties, metal-organic framework are promising materials for use in gas separation. In the present work, both the Monte Carlo and equilibrium molecular dynamics methods were employed to examine the temperature dependence of membrane selectivity and nitrogen permeability for separation of an equimolar mixture of N2 and He by a HKUST-1-based membrane at a pressure drop of 0.1, 0.3, and 1 MPa. It was shown that the selection of optimal temperature conditions made it possible to obtain a significant increase in membrane selectivity and permeability for nitrogen compared to corresponding parameters at room temperature. [ABSTRACT FROM AUTHOR]

Trends and methods of solving the problem of creating a complete technological chain from raw materials to high-purity rare-earth products in Russia have been considered. The need to create an information support system in the industry has been discussed and a possible way to implement one has been proposed. [ABSTRACT FROM AUTHOR]

Design of a flat-chamber type of electrobaromembrane device and procedure for calculating permeate flow rate and increased effective membrane area are developed for cleaning chemical, engineering, and food industry process solutions. [ABSTRACT FROM AUTHOR]

On the basis of the universal Kennard-Stepanov-van Roosbroeck-Shockley relation, a general approach is proposed for separation of the contributions of homogeneous and inhomogeneous broadenings in the absorption and luminescence spectra of colloidal quantum dots. The applicability of the developed method is demonstrated on published experimental data. [ABSTRACT FROM AUTHOR]

This paper describes a method for the separation and purification of Sr from PUREX-HLLW employing solvent extraction and precipitation techniques. 30 % TBP in n-dodecane was used for the removal of residual uranium, plutonium and neptunium from HLLW. Trivalent actinides and lanthanides were subsequently removed using N, N, N', N'-tetra(2-ethylhexyl) diglycolamide (TEHDGA, 0.20 M in 30 % isodecyl alcohol and n-dodecane). Sr was selectively extracted from actinides and lanthanides depleted HLLW using 0.3 M TEHDGA in 5 % isodecyl alcohol and dodecane. Loaded strontium was stripped using 0.01 M HNO and further purified by radiochemical precipitation technique after adding Fe and natural strontium as carriers. Based on the experimental results, a flow-sheet was formulated and mCi levels of Sr recovered. [ABSTRACT FROM AUTHOR]

In this study we describe a method for uranium dating (i.e. determination of the date of the last chemical purification undergone by the material) by measurement of the Th/U ratio, applicable to sub-microgram quantities. The chosen protocol (AG1x8 resin in hydrochloric acid medium) has been tested on separation microcolumns (100 μl). This 'microchemistry' technique considerably limits the risks of contamination by reagents or the environment. Thorium extraction efficiencies were greater than 90 % and reproducible. The quantities of Th introduced by the chemical purification procedure were negligible. Using an ultra-sensitive inductively coupled plasma mass spectrometry measurement technique, detection limits of the order of femtograms (10 g) of Th were obtained. The complete procedure, chemical separation and isotope measurement, was successfully tested and validated on a few micrograms of uranium. [ABSTRACT FROM AUTHOR]

Physicochemical substantiation and improved more effective technologies for C-hydrocarbons separation and 1,3-butadiene purification with the help of polar extragents are given, such as compressorless extractive rectification with the use of an intermediate desorbent, extractive rectification of the butane- n-butene fraction with preliminary isomerization of 1-butene into 2-butenes, the combined removal of -acetylenes C and methylallene by rectification with a small introduction of the extragent, and the hydration of butenyne in the C fraction and distillation of propyne from it. [ABSTRACT FROM AUTHOR]

This paper discusses basic distinctions and challenges of available commercial process technologies for fractionation of phenol and acetone products, and for removal of contaminants therefrom. Theoretical improbability of complete removal of impurities from the desired products under fractionation process conditions is conclusively demonstrated. The challenge of achieving an adequate quality of desired products (i.e., of phenol, acetone, and α-methylstyrene) has been effectively met within the framework of state-of-the-art phenol/acetone production process. [ABSTRACT FROM AUTHOR]

Separation and purification of133Xe from acidic solution containing uranium,99Mo and131I has been developed. In the first step of this work, uranium pellets were dissolved under pressure (8-15 bar) in 8M nitric acid solution. Then133 Xe and other gases were conducted to activated charcoal cold trap. Final purification of133Xe from impurities such as NO x, radioiodine and krypton was performed by passing through a molecular sieve preparative chromatographic column using helium as mobile phase. The final recovery of133Xe from the separation-purification process was higher than 98%. Adsorption-desorption behavior of radioxenon on the charcoal and molecular sieves have also been studied and discussed. [ABSTRACT FROM AUTHOR]

Abstract  The conditions for the sulfation of rough baddeleyite concentrate to remove impurity minerals were studied. [ABSTRACT FROM AUTHOR]

The article focuses on the separation and purification of daphnetin, daphnodorin B, p-hydroxybenzoic acid, and daphnodorin D 1 in Daphne odora var. Margirmt plant through high-speed counter-current chromatography (HSCCC). It explains that Daphne odora var. Margirmt is a flower and medical plant from the family of Thymelaeaceae. It cites how the dried plant was chopped into small pieces and extracted with a solvent mixture that composed of 95% ethyl acetate and ethanol.