123 research outputs found
Studying mathematical model of mine and quarry pneumatic lifting equipment in "skip - guidance devices" systems
There are two basic ways of mining: open pit and underground in the mining industry: open pit and underground. Underground mining less profitable, however, it is more environmentally friendly. In addition, this method is essentially inevitable due to the fact that the major mineral reserves are at greater depths and in the future will need to solve the problems of development of mineral deposits deep mines. The development of the mining sector and the deepening of mining operations require a new type of transport, justified and developed in the works of Bogatyrev M. D., Kiselev V. I., Kartaviy N. G., Saginov A. S., Nechyporenko S. N., Piskunov O. M., Nikolaev Yu. A. - skip pneumatic lifting equipment designed to reduce the cost of transportation of the rock mass
Structure and Phase Composition of V-Al-N-C Master Alloy
The article presents the results of studying the phase composition and microstructure of the V-Al-N-C alloy, intended mainly for doping titanium alloys, but also of interest to manufacturers of structural steels. The V-Al-N-C alloy was obtained by the method of out-of-furnace aluminothermic smelting of a mixture containing vanadium pentoxide, aluminum powder, nitrided by the SHS method powdered V-Al-(17-20)N (wt.%) alloy and graphite in copper uncooled molds. The phase composition was determined by X-ray phase analysis (diffractometer - DRON-2.0, radiation - Cu-Kα, monochromator - graphite). The microstructure and composition of the phases were investigated by X-ray microanalysis using a JSM-59000LV scanning electron microscope ( Japan) and an Oxford INCA Energy 200 energy-dispersive X-ray spectrometer (United Kingdom). It is revealed that the matrix of the V-Al-N-C alloy, containing (wt. %): 73.9 V; 23.7 Al, 1.2 N, 0.69 C, and 0.08 O2, are represented by the solid solution of aluminum in vanadium. The main nitrogen-containing phase is aluminum nitride AlN of a cubic structure. The carbide phase can be identified as V2Al0.9C1.1. Nitride and carbide phases are distributed quite uniformly in the alloy matrix. The carbide phase in the structure of the V-Al-N-C alloy is predominantly in the form of threadlike crystals up to 100 μm in length. The nitride phase is represented by small (up to 10 μm) and large (30 ÷ 10
Method of combating fatigue destruction of steel structures of mine hoisting machines
The article presents the information of the identified defects of fatigue failure of steel structures of the brake mechanism of mine cable hoisting machines used to transport metallurgical coke from the mine to the surface. Using non-destructive testing methods a survey was carried out of the brake mechanisms of sixty mine cable hoisting machines. A method was developed to combat the fatigue failure of steel structures through the use of reinforcing elements to reduce their metal consumption and increase resistance to fatigue failure, while the use of expensive high-strength alloys is completely eliminated. To study the stress-strain state and fatigue failure of steel structures, a computer simulation method was used. Using the ANSYS computer program, the optimal forms of reinforcing elements were established and the loaded part of steel structures in continuous operation was simulated. Eleven computer models of a steel beam with various reinforcing elements were developed. The research results were used in practice in the repair of steel structures
Surgical ulcerative gastroduodenal bleeding in patients with pyloroduodenal stenosis
Analysis of surgical treatment of 106 patients with ulcerative gastroduodenal hemorrhage arising in the presence of pyloroduodenal stenosis of varying severity. The patients were divided into 2 groups: 50 people, made a comparison group received traditional surgical treatment, and 56 people. A group of patients who received surgical treatment developed. It is shown that the application of a rational preoperative surgicaltion election tactics and postoperative therapy with the introduction of oxygen-containing solution intraenteric improve treatment outcomes
Making complex things simpler: modern tools to edit the plant genome
There are several technologies for plant genome editing, of which the most simple and universal is CRISPR/Cas. Currently, this technology is widely used for gene knockout, deleting genome fragments and inserting exogenous sequences in the plant genome. For each of these applications, many different types of genetic tools have been developed that are used by various research groups to solve specific problems. The CRISPR/Cas technology for plant genome editing is at an early stage of optimization, which is reflected by the ongoing search for the most effective, simple and flexible techniques. As a result, experimental work has to be preceded by a rather long and laborious process of selecting a genetic tool that will be optimal for a specific experimental task. In our review we describe the main variants of the CRISPR/Cas technology used to edit a plant genome. We classify them in terms of experimental tasks solved, major components and technology performance. In the first half of the review a detailed description of two major components of CRISPR/Cas technology – nuclease and guide RNA – is given, the effect of structural features of these elements on editing efficiency is analyzed. Experimental data on the relationship between editing efficiency and nucleotide sequence of guide RNA are generalized. We also give the characteristic for different variants of nucleases used for plant genome editing and discuss their benefits for different experimental purposes. In the second half of the review various strategies for expression of CRISPR/Cas elements in plant cells, in particular, advantages and disadvantages of stable transformation and transient expression, are discussed. The effect of various regulatory elements of genes encoding nuclease and guide RNA on editing efficiency is described. Special emphasis is placed on the techniques of increasing targeted gene replacement efficiency
БЛОКЧЕЙН бИТКОИН: Типология участников
The paper describes the classification and criteria for blockchain environment participants. The overview of the main types of blockchain participants is essential for the understanding of blockchain social and economic behaviour. It structured in the description of the several patterns which is often generated inside the Bitcoin blockchain and the list of the economic entities with the criteria of their behaviour. The paper gives the view on the different types of blockchain entities both from outside and inside the blockchain. Also, the paper lists the possible risks of criminal behaviour corresponding to every entity.El artículo describe la clasificación y los criterios para los participantes del entorno de blockchain. La descripción general de los principales tipos de participantes de blockchain es esencial para la comprensión del comportamiento social y económico de blockchain. Se estructura en la descripción de los diversos patrones que a menudo se generan dentro de la cadena de bloques de Bitcoin y la lista de las entidades económicas con los criterios de su comportamiento. El documento ofrece una vista de los diferentes tipos de entidades de blockchain tanto desde fuera como desde dentro de blockchain. Además, el documento enumera los posibles riesgos de comportamiento criminal que corresponden a cada entidad.В статье описывается классификация и критерии классификации участников блокчейн среды. Обзор основных видов блокчейн участников имеет важное значение для понимания социального и экономического поведения в блокчейн. Статья структурирована как описание нескольких моделей, которые часто возникают внутри блокчейн Биткоин и перечень хозяйствующих субъектов с критериями их поведения. В статье дается представление о различных типах блокчейн структур со взглядом как снаружи, так и внутри блокчейн. Кроме того, в документе перечислены возможные риски преступного поведения, соответствующего каждому объект
The tissue distribution of SARS-CoV-2 in transgenic mice with inducible ubiquitous expression of hACE2
The novel coronavirus disease COVID-19 has become one of the most socially significant infections. One of the main models for COVID-19 pathogenesis study and anti-COVID-19 drug development is laboratory animals sensitive to the virus. Herein, we report SARSCoV- 2 infection in novel transgenic mice conditionally expressing human ACE2 (hACE2), with a focus on viral distribution after intranasal inoculation. Transgenic mice carrying hACE2 under the floxed STOP cassette [(hACE2-LoxP(STOP)] were mated with two types of Cre-ERT2 strains (UBC-Cre and Rosa-Cre
Efficiency of thermoprotectors in the practice of catastrophe medicine, mechanism of action
The article describes the main groups of modern thermal protectors used from the adverse effects of high temperatures during search and rescue operations. Their possible applications, application prospects and relevance to date are described.В статье рассмотрены основные группы современных термопротекторов, используемых от неблагоприятного воздействия высокихтемператур во время поисково-спасательных работ. Описаны их возможныеварианты применения, перспективы применения и актуальность на сегодняшний день
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