Metasomatic alteration associated with the formation of subvolcanic rocks of the Abagatuysky complex (Nerchinsk ore region, Eastern Transbaikalia)

Within the northeastern edge of the Borschovochny pluton, located in Eastern Transbaikalia, a complex of small intrusions is localized, represented by the subvolcanic bodies of the Early Cretaceous Abagatuysky andesite-dacite complex. These intrusions, along with significant dynamometamorphic (tectonic) transformations, produced the development of metasomatic alteration, united in three large rock associations — propylites, beresites, and argillisites. These metasomatic associations successively replace each other as they move away from the center of heat exposure of intrusions. In addition, each of these groups of metasomatites has its own unique internal mineral zonality, and the most productive of them, on the subject of gold ore mineralization, is the beresite association

Composition and conditions of the late Mesozoic volcanism occurrence of the northern part of the Borschovochny ridge (Eastern Transbaikalia)

On the basis of geochemical study results composition heterogeneity and formation conditions of late Mesozoic subvolcanic rocks from northern part of Borschovochny ridge by an example of shadoronsky and abgatuysky complexes are discussed. Obtained results show that volcanic rocks of both complexes have heterogeneous composition and differ from each other in level and other features of alkalinity. Rare and trace elements geochemistry study results show that there is a significant enrichment with LILE (Cs, Rb, Ba) and some depletion with HFSE (Nb, Ta), meanwhile the correlation between Th and Yb indicates conditions of active continental margin. Gd/Yb and La/Sm ratios allow to conclude that shadoronsky complex rocks originated from garnet-stable mantle source (partial melting of 5% of garnet peridotite), while abagatuysky complex rocks originated from transitional garnet-spinel mantle

Magnetic properties of thin Ni films measured by a dc SQUID-based magnetic microscope

We have applied a scanning HTS (high-temperature superconductor) de SQUID (superconducting quantum interference device) -based magnetic microscope to study the magnetic properties of Au/Ni/Si(100) films in the thickness range from 8 to 200 Angstrom at T = 77 K. A one-domain structure with in-plane orientation of the magnetic moment was found for film thicknesses exceeding 26 Angstrom. A drastic decrease of the magnetization of the film was detected when the thickness is less than 26 Angstrom

PSA-stage Features of the Hybrid Membrane-sorption Oxygen Concentrator

The paper considers the principle of the organization of the hybrid membranesorption oxygen concentrator and the work of the PSA stage of the hybrid system. The use of hybrid membrane-sorption gas separation systems can significantly reduce the energy consumption of plants, as well as to neutralize such disadvantages as contamination of the product flow by the products of abrasion of sorbents, through the use of highly selective polymer membrane, and the restriction on the oxygen concentration when using a single membrane stage, through its use after the PSA stage. In this paper, we propose an arrangement for the operation of the PSA stage of a hybrid system consisting of three adsorbers and providing a constant product flow of the PSA stage necessary to ensure continuous feed flow to the membrane stage of the system. Each of the adsorbers in this system passes through three main stages: filling, displacement (adsorption), and discharge (desorption). Moreover, the filling is not from the compressor, but part of the product flow of the displaced adsorber. The results of the operation of the system organized by the proposed method are compared with the results of the operation of modern gas separation systems on the market.     Keywords: Sorption, air separation, pressure-swing adsorption, PSA, hybrid technologies, oxygen concentrator, recycling, oxyge

Geological structure and prospects of noble metal ore mineralization of the Khayrkhan gabbroid massif (Western Mongolia)

An analysis of the distribution of noble metals in zones of sulfide mineralization makes it possible to justify the isolation of four ore-bearing horizons with a specific geochemical zonation. A rise in the gold content relative to palladium and platinum is observed from the bottom upwards along the section of the stratified series of gabbroids. The study of the mineral phases of sulphides and the noble minerals itself indicates the evolution of hydrothermal solutions, which determines the different activity and mobility of the fluid (mercury, tellurium, sulfur) and ore (copper, nickel, iron, platinum, gold and silver) components