scholarly journals Definition of the Existence Region of the Solution of the Problem of an Arbitrary Gas-dynamic Discontinuity Breakdown at Interaction of Flat Supersonic Jets with Formation of Two Outgoing Compression Shocks

Author(s):  
Pavel Viktorovich Bulat ◽  
Mikhail Pavlovich Bulat
1986 ◽  
Author(s):  
S. W. Stiller ◽  
B. D. Anderson ◽  
M. V. Johnston

Author(s):  
A Blahodarnyi ◽  
I Koziakov ◽  
L Strelbytska ◽  
M Strelbytskyi

Purpose.To study the main elements of mining safety, as well as to formulate the definition of the concept of mining safety for its use in legal regulations of mining relations from the viewpoint of scientific literature and the norms of current legislation. Methodology.The results were obtained after applying a set of methods: a) general philosophical methods (dialectical, anthropological);b) general scientific methods (abstraction, analysis and synthesis, system analysis, classification);c) legal methods (historical and legal, comparative legal, semantic and legal). Findings.Based on the analysis of the main categories of general security theory and their application in the legislation of Ukraine, the etymology of the legal term security is studied and it is shown that the definition of this concept depends on the context of the normative legal act in which it is used. This necessitates the improvement of the conceptual apparatus of mining legislation and the development of the category mining safety. It is argued that unification of this legal category and clarification of its authentic definition will contribute to the achievement of unity and consistency of the current mining legislation, the proper regulation of public relations to ensure protection of Ukraines national interests in the field of subsoil use. The necessity of expanding the list of possible hazards of geological study and subsoil use provided for by the current legislation was substantiated. It is proposed to consolidate the authors definition of mining safety in the corresponding paragraph of Article 1 of the Mining Law of Ukraine. Originality.As a result of lexical and legal analysis, it was concluded that the definition of security depending on the context of the legal act in which it is used and the characteristics of the subject of legal regulation of certain social relations is defined as: security; security status; provision (regulatory compliance); set of measures; aggregate of nonuniform resources. Taking into account the geospheric characteristics of subsoil, as well as the peculiarities of hazard occurrence and manifestation during subsoil use, the authors put forward a classification of hazards manifestation during mining operations (geomorphological, lithospheric, geodynamic, gas-dynamic, hydrodynamic, geopathogenic, microbiological hazards, as well as the hazards of mineral nanoparticles). The additions are substantiated to the current legislation (part 1 of Article 1 of the Mining Law of Ukraine) with the following definition of the safety of mining operations: protection of vital interests of a person, society and the state from negative manifestations of geomorphological, lithospheric, geodynamic, gas-dynamic, hydrodynamic, geopathogenic, microbiological and other factors in the course of processes aimed at carrying out, securing and maintaining mine workings and withdrawing mining rocks. Practical value.The practical significance of the results is based on the fact that they can be used by the subjects of legislative initiative when improving the provisions of the current legislation of Ukraine, as well as by practical workers to organize and conduct mining operations.


2021 ◽  
Vol 2119 (1) ◽  
pp. 012055
Author(s):  
V A Tenenev ◽  
M R Koroleva ◽  
A A Chernova

Abstract The paper considers the numerical simulation of spatial flows of real media in safety valves on the basis of the problem of an arbitrary discontinuity breakdown with complex equations of state. The solution is constructed by means of the developed numerical method, which is a modification of the classical scheme by S. K. Godunov and includes various complex equations of state of matter. The Van der Waals equations of state were used to model the flow of real gases, and the Mie-Grüneisen equation was used to describe the flow of a real weakly compressible fluid. It is shown that the proposed numerical schemes allow for modeling fluid and gas dynamic processes in real fluids and gases with shock waves and contact discontinuities and can be used both in areas of classical medium behavior and in areas with non-classical behavior.


Author(s):  
М.Г. Бергер

Существуют определенные аналогии в механизме проявления субвулканических, вулканических и поствулканических газодинамических процессов взрывного или взрывоподобного типа. По вполне достоверно зафиксированным многими исследователями особенностям их проявления, к последним из них относится взрывоподобный газодинамический выброс ледника Колка. Наиболее существенный элемент сходства между этими процессами состоит в их газодинамическом характере, участии в качестве основного рабочего тела в их проявлении природных газов, имеющих высокое, а на отдельных этапах сверхвысокое давление. Именно этот момент представляет наибольший интерес при изучении катастрофической пульсации ледника Колка, определении ее природы, идентификации ее геодинамического типа. Существование аналогий между пароксизмальным взрывоподобным выбросом ледника Колка и процессами формирования и функционирования субвулканических трубок взрыва проливает дополнительный свет на некоторые детали процессов подготовки и проявления этой пульсации. Диатремоподобная морфоструктура (крупная выемка, представляющая собой в ее верхней части устье газовыводящего канала) существует в тыльной части ложа ледника Колка в узле пересечения субширотного СырхуБарзондского и субмеридионального ВосточноДжимарайского разломов. Происхождение данной выемки связано с концентрированным интенсивным прорывом огромного количества высоконапорных глубинных поствулканических газов, их мощным воздействием на горные породы в зоне прорыва и последующим взрывоподобным газодинамическим выбросом ледника, а также некоторого количества материала его горнопородного субстрата из верхней части газовыводного канала, на месте которой возникла диатремоподобная выемка. Заполнение же этой выемки произошло, в основном, в результате обрушения ее стенок, обратного падения в нее части выброшенного материала и поступления материала последующих обвалов, а отчасти, возможно, за счет привноса материала продуктов разрушения нижележащих пород восходящим газовым потоком, продолжавшимся какоето время после выброса ледника (до исчерпания основного количества прорвавшихся в эту зону высоконапорных глубинных газов). There are certain analogies in the manifestation mechanism of subvolcanic, volcanic and postvolcanic gasdynamic processes of explosive or explosionlike type. According to the features of their manifestation quite reliably recorded by many researchers, the latter of them includes the explosive gasdynamic outburst of the Kolka glacier. The most essential element of the similarity between these processes consists in their gasdynamic character, the participation of natural gases of a high and at some stages an extremely high pressure as their main working body in their manifestation. This moment is of the greatest interest in the study of the catastrophic pulsation of the Kolka glacier, the definition of its nature, the identification of its geodynamic type. The existence of analogies between the paroxysmal explosionlike ouburst of the Kolka glacier and the processes of formation and functioning of subvolcanic volcanic pipes sheds additional light on some details of the preparation processes and manifestation of this pulsation. The diatremelike morphostructure (a large cavity representing the mouth of the gasproducing channel in its upper part) exists in the back of the Kolka glacier bed at the intersection point of the sublatitudinal SyrkhuBarzond and submeridional EastDzhimarai faults. The origin of this cavity is associated with a concentrated intense breakthrough of a huge amount of highpressure deep postvolcanic gases, their powerful effect on rocks in the breakthrough zone and the subsequent explosive gasdynamic outburst of the glacier, as well as a certain amount of material of its rockbearing substrate from the upper part of the gas output channel, in the place of which diatremelike cavity. The filling of this cavity occurred mainly as a result of the collapse of its walls, the inverse fall of a part of the outburst material and the receipt of subsequent collapses material, and partly, possibly, due to the introduction of material from the products of destruction of the underlying rocks with an ascending gas flow that lasted for some time after the ouburst of the glacier (until the main amount of highpressure deepwater gases has broken through into this zone).


1966 ◽  
Vol 24 ◽  
pp. 3-5
Author(s):  
W. W. Morgan

1. The definition of “normal” stars in spectral classification changes with time; at the time of the publication of theYerkes Spectral Atlasthe term “normal” was applied to stars whose spectra could be fitted smoothly into a two-dimensional array. Thus, at that time, weak-lined spectra (RR Lyrae and HD 140283) would have been considered peculiar. At the present time we would tend to classify such spectra as “normal”—in a more complicated classification scheme which would have a parameter varying with metallic-line intensity within a specific spectral subdivision.


1975 ◽  
Vol 26 ◽  
pp. 21-26

An ideal definition of a reference coordinate system should meet the following general requirements:1. It should be as conceptually simple as possible, so its philosophy is well understood by the users.2. It should imply as few physical assumptions as possible. Wherever they are necessary, such assumptions should be of a very general character and, in particular, they should not be dependent upon astronomical and geophysical detailed theories.3. It should suggest a materialization that is dynamically stable and is accessible to observations with the required accuracy.


1979 ◽  
Vol 46 ◽  
pp. 125-149 ◽  
Author(s):  
David A. Allen

No paper of this nature should begin without a definition of symbiotic stars. It was Paul Merrill who, borrowing on his botanical background, coined the termsymbioticto describe apparently single stellar systems which combine the TiO absorption of M giants (temperature regime ≲ 3500 K) with He II emission (temperature regime ≳ 100,000 K). He and Milton Humason had in 1932 first drawn attention to three such stars: AX Per, CI Cyg and RW Hya. At the conclusion of the Mount Wilson Ha emission survey nearly a dozen had been identified, and Z And had become their type star. The numbers slowly grew, as much because the definition widened to include lower-excitation specimens as because new examples of the original type were found. In 1970 Wackerling listed 30; this was the last compendium of symbiotic stars published.


Author(s):  
K. T. Tokuyasu

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).


Author(s):  
W. A. Shannon ◽  
M. A. Matlib

Numerous studies have dealt with the cytochemical localization of cytochrome oxidase via cytochrome c. More recent studies have dealt with indicating initial foci of this reaction by altering incubation pH (1) or postosmication procedure (2,3). The following study is an attempt to locate such foci by altering membrane permeability. It is thought that such alterations within the limits of maintaining morphological integrity of the membranes will ease the entry of exogenous substrates resulting in a much quicker oxidation and subsequently a more precise definition of the oxidative reaction.The diaminobenzidine (DAB) method of Seligman et al. (4) was used. Minced pieces of rat liver were incubated for 1 hr following toluene treatment (5,6). Experimental variations consisted of incubating fixed or unfixed tissues treated with toluene and unfixed tissues treated with toluene and subsequently fixed.


Sign in / Sign up

Export Citation Format

Share Document