Herein we present the structural and mechanical properties of polyurethanes synthesized from amino ethers of boric acid for gas separation. The polymers were characterized by light scattering ...methods, conductivity measurements, thermal gravimetric analysis, Fourier transform infrared spectroscopy, and atomic force microscopy. Additionally, the permeability of ammonia and carbon dioxide, as well as the selectivity for their diffusion and resultant impurity are presented. The results illustrate the steric hindrance, resulting in a branched architecture borate formation, leads to intermolecular complexation which may assist the polymer in ammonia diffusion selectivity.
Herein we present the structural and mechanical properties of polyurethanes synthesized from amino ethers of boric acid for gas separation.
To study pseudoautosomal and bordering regions in the avian Z and W chromosomes, we used seven BAC clones from genomic libraries as DNA probes of fragments of different gametologs of the
ATP5A1
gene ...located close to the proximal border of the pseudoautosomal region (PAR) of sex chromosomes of domestic chicken and Japanese quail. Localization of BAC clones TAM31-b100C09, TAM31-b99N01, TAM31-b27P16, and TAM31-b95L18 in the short arm of Z chromosomes of domestic chicken and Japanese quail (region Zp23-p22) and localization of the BAC clones CHORI-261-CH46G16, CHORI-261-CH33F10, and CHORI-261-CH64F22 on W chromosomes of these species and in the short arm of Z chromosomes (region Zp23-p22) were determined by fluorescence in situ hybridization with the use of W-specific probes. The difference in the localization of the BAC clones on the Z and W chromosomes is probably explained by divergence of the nucleotide sequences of different sex chromosomes located beyond the pseudoautosomal region.
Thin films of GaS
х
are obtained via plasma-enhanced chemical vapor deposition (PECVD) for the first time, while high-purity volatile derivatives of the corresponding macrocomponents (gallium ...chloride (GaCl
3
) and hydrogen sulfide (H
2
S)) are used as the initial materials. It is found that the nonequilibrium low-temperature plasma of an HF discharge (40.68 MHz) at a reduced pressure (0.01 Torr) is the initiator of chemical transformations. Components of reactive plasma formed in the gas phase are studied via optical emission spectroscopy (OES). Structural and electrophysical properties of the obtained materials are studied as well.
The processes of biodeterioration of the unique Tomskaya Pisanitsa monument of rock art in Western Siberia have been studied by a complex of biological and mineralogical methods. The species ...composition of the lithobiotic community (bacteria, fungi, and lichens) is identified using a complex of cultural, morphological, and molecular genetic methods. It is shown that the destruction of the monument is a result of interrelated physical, chemical, and biological processes, accompanied by a change in the properties of the rock and its biological colonization. The structure of microbial communities depends on the local environment and successional processes. The development of biofilms with the dominance of cyanobacteria is observed on the rock zones of increased moisture and the formation of carbonate crusts. The problems of adaptation of the lithobiotic microorganisms to existence at the Tomskaya Pisanitsa rock art monument, as well as their role in the processes of oxalate and carbonate biomineralization, are discussed. The results point to the danger of deterioration of Tomskaya Pisanitsa monument and indicate the need to find new effective ways to protect it, taking into account the accumulated scientific data.
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Different types of biomineral layers have been identified and characterized on the monuments of rock art in Minusinsk Basin. On the surface of the sandstone (on which images were applied in ancient ...times), cyanobacterial biofilms and biofouling with the dominance of lichens, mosses, and primary soils have developed, and mineral crusts have formed that are to a greater or lesser extent inhabited by microorganisms. Monospecies cyanobacterial biofilms formed by
Gloeocapsopsis magma
are a dominant form of biofouling on open rock surfaces exposed to the intense insolation. The most noticeable development of microorganisms was noted on light-colored calcite-bearing crusts with a porous surface. On the contrary, gypsum crusts are poor in organic matter and are almost uninhabited by microorganisms. The formation of gypsum crusts leads to serious damage to the surface layer of the stone and can be one of the main processes leading to the loss of the rock art.
A new polymer composite material based on furfural-acetone monomer, crude tall oil and its fatty acids, which are waste from the pulp and paper industry, was obtained. In this paper, the effect of ...crude tall oil and its fatty acids on furfural-acetone monomer binder in a composite material is considered. The composition for the composite material, consisting of FA monomer, filler and catalyst p-toluenesulfonic acid, was modified with crude tall oil additives or tall oil fatty acids. It was shown that the compressive strength of composite samples after 30-day exposure at room temperature, obtained with a reduced amount of furfural-acetone monomer and the introduction of 100% fatty acids of tall oil from the furfural-acetone monomer content, increases by 37%, with the introduction of 150% fatty acids of tall oil, the strength increases slightly - by 1.5%, but the density increases significantly and water absorption decreases with respect to the standard sample. Additives of crude tall oil (up to 150% of furfural-acetone monomer) lead to an increase in density, a decrease in water absorption - by 84%, but reduce the compressive strength of samples by 12%. The improvement in the physicochemical properties of the composite material was explained by the alleged chemical interaction of tall oil fatty acids with mono- and difurfurilideneneacetone (furfural-acetone monomer), which takes place with the formation of new polymers. This is confirmed by DTA data, chromatograms of the furfural-acetone monomer - fatty acids of tall oil (TLC) mixture, and IR spectra. The use of fatty acids of tall oil or crude tall oil, non-expensive, non-toxic products of natural origin in the composite material, can reduce the consumption rates of furfural-acetone monomer and improve the quality of the polymer.
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