Properties and structure of precipitation baths in viscose manufacture

Conclusions To spin viscose fibre, it is necessary to choose such a composition of the precipitation bath solutions that the water structure in them is broken up; that is, in electrolyte concentration they are above the transition region.In a bicomponent bath, that is, in solutions of the H₂SO₄-Na₂SO₄-H₂O system, it is not possible to improve viscose fibre spinning conditions by changing the composition and concentrations of the components (without additions of other ions or large quantities of organic substances).To select the optimum precipitation bath composition and replace scarce zinc, it is recommended to use magnesium sulfate or aluminum sulfate.Translated from Khimicheskie Volokna, No. 4, pp. 10–13, July–August, 1986.     

The EDU—AVT—3 Unit at Komsomol'sk Refinery. Comprehensive Revamping

The EDU—AVT—3 with crude oil output of 3 million tons/year was started up at Komsomol'sk Refinery (Komsomol'sk—na—Amure) in 1978. It is one of the most successful Azgiproneftekhim projects with respect to the process scheme, equipment, and layout. The unit had been operating for more than 20 years at the time of revamping, and almost all of the equipment was outdated, individual design faults appeared, and most important, it became necessary to increase productivity, decrease power consumption, and improve the quality of the products produced.     

Strain hardening of metastable austenitic steel under repeated simple loading at different temperatures

On the basis of experimental data obtained under repeated simple loading of 18-10 steel at temperatures of 77, 123 and 293 K, we discovered that the direction of maximum hardening in the space of stresses does not coincide with the direction of preloading. This effect becomes more pronounced if preloading and repeated loading are performed at different temperatures. It is shown that the maximum degree of hardening is attained after repeated loading preceded by uniaxial preloading in the direction of trajectories close to uniform biaxial tension. It is also noted that the yield surface of structurally unstable steel undergoes complicated transformations.     

Expression and function of CCR5 and CXCR4 on human Langerhans cells and macrophages: implications for HIV primary infection

Transmission of HIV-1 is predominantly restricted to macrophage (Mphi)-tropic strains. Langerhans cells (LCs) in mucosal epithelium, as well as macrophages located in the submucosal tissues, may be initial targets for HIV-1. This study was designed to determine whether restricted transmission of HIV-1 correlates with expression and function of HIV-1 co-receptors on LCs and macrophages. Using polyclonal rabbit IgGs specific for the HIV co-receptors cytokines CXCR4 and CCR5, we found that freshly isolated epidermal LCs (resembling resident mucosal LCs) expressed CCR5, but not CXCR, on their surfaces. In concordance with surface expression, fresh LCs fused with Mphi-tropic but not with T-tropic HIV-1 envelopes. However, fresh LCs did contain intracellular CXCR4 protein that was transported to the surface during in vitro culture. Macrophages expressed high levels of both co-receptors on their surfaces, but only CCR5 was functional in a fusion assay. These data provide several possible explanations for the selective transmission of Mphi-tropic HIV variants and for the resistance to infection conferred by the CCR5 deletion.