scholarly journals Influence of wind conditions and pressure the influence of atmospheric air on the reliability of mine ventilation and the human body

2021 ◽  
pp. 148-159
Author(s):  
И.Д. Алборов ◽  
В.Б. Заалишвили
Keyword(s):  
Human Body ◽  
Ventilation System ◽  
Barometric Pressure ◽  
Work Capacity ◽  
Ventilation Network ◽  
High Mountain ◽  
Atmospheric Air ◽  
Air Supply ◽  
The Stability ◽  
Different Levels

Статья посвящена обоснованию учета естественной тяги на эффективность и надежность проветривания рудников со сложной вентиляционной сетью при многоштольневом вскрытии месторождений полезных ископаемых. Цель работы. Показан уровень на легкие горнорабочих в условиях пониженного атмосферного давления. В статье приведены результаты исследований по влиянию метеорологических и геофизических факторов на надежность проветривания вентиляционных систем в условиях высокогорья. Показана динамика влияния ветровых потоков при штольневом вскрытии месторождений на устойчивость воздухоснабжения горных выработок и шахт в целом. Методы работы. Дается теоретические формулы по расчету естественной тяги при различных направлениях вектора скорости воздушных потоков на дневной поверхности. Приведен метод учета естественной тяги в различных уровнях барометрического давления. Результаты работы. Показан учет барометрического коэффициента при различных уровнях расположения горной выработки над уровнем моря. Показано, что без учета геофизических факторов метеоусловий местности обеспечение надежного проветривания рабочих мест рудника невозможно. Отмечено, что снижение парциального давления кислорода в альвеолах легких приводит к нарушению нормального ритма дыхательной функции организма человека. Это способствует к развитию дисфункции и ослаблению резистентности человека и к иным заболеваниям, что снижает потенциальную работоспособность и профессиональные качества трудящегося. Вводятся соответствующие корректирующие коэффициенты по нормируемой запыленности и по системе вентиляции для обеспечения надежной работы при всех отклонениях. Дается рекомендации по учету барометрического давления при нормировании вредных выделений в рудничную атмосферу. Предлагаемое решение учета давления атмосферного воздуха рекомендовано Госгортехнадзору и Государственным учреждениям санитарно-гигиенического нормирования внести в коррективы по нормированию вредных веществ в воздухе рабочей зоны с учетом барометрического коэффициента, что позволит снизит нагрузку на легкие работающих и уровень профзаболевания горняков. The paper is devoted to substantiation of consideration of natural draught on efficiency and reliability of ventilation of mines with complex ventilation network in multi-wall opening of mineral deposits. The level on lungs of miners in conditions of reduced atmospheric pressure is shown. Aim. The article presents the results of studies on the influence of meteorological and geophysical factors on the reliability of ventilation systems in high mountain conditions. It shows the dynamics of the influence of wind flows during adit opening of deposits on the stability of air supply of mine workings and mines as a whole. The theoretical formulas for calculating the natural draught at different directions of the velocity vector of air flows on the day surface are given. Methods. The method of taking into account the natural draught in different levels of barometric pressure is given. Consideration of the barometric coefficient at different levels of the location of the mine above sea level is shown. Results. It is shown that without taking into account geophysical factors of meteorological conditions of the area to ensure reliable ventilation of working places of the mine. It is noted that the decrease of the partial pressure of oxygen in the lung alveoli leads to disturbance of the normal rhythm of the respiratory function of the human body. This contributes to the development of dysfunction and weakening of human resistance and other diseases, which reduces the potential work capacity and professional qualities of the worker. Appropriate correction factors for normalized dustiness and ventilation system are introduced to ensure reliable operation under all deviations. Recommendations are given for taking into account barometric pressure when rationing harmful emissions into the mine atmosphere.The proposed solution for taking into account atmospheric air pressure is recommended to Gosgortechnadzor and State institutions of hygienic rationing to make adjustments for rationing harmful substances in working area air with regard to the barometric factor, which will reduce the burden on workers' lungs and the level of occupational diseases of miners

Calculation of Air Flows Stability in the Mine Workings by the Factor of Thermal Depression in the Analytical Complex «Aeroset»

2020 ◽  
pp. 24-32
Author(s):  
M.D. Popov ◽  
◽  
D.S. Kormshchikov ◽  
M.A. Semin ◽  
L.Yu. Levin ◽  
...  
Keyword(s):  
Air Flow ◽  
Ventilation System ◽  
Numerical Algorithms ◽  
Mine Ventilation ◽  
Heat Emission ◽  
Graphical Analysis ◽  
Ventilation Network ◽  
Mining Operations ◽  
Mine Workings ◽  
The Stability

Underground fires are one of the most serious emergencies that occur during mining operations. Analysis of possible scenarios for its development is a mandatory measure when designing new mine workings and when developing a plan for immediate elimination of accidents at the existing mine workings. The main danger that an underground fire creates for the mine ventilation system is a change in the ventilation mode and, accordingly, a change in the direction of movement of the air and harmful gases released during combustion. It is almost impossible to calculate in manual mode all the possible scenarios for the development of an emergency for different places where underground fires occur. This confirms the need to develop algorithms for automated assessment of the effect of thermal depression from a fire on the stability of the air flow in all mine workings of the mine ventilation network. The authors consider two numerical algorithms implemented in the «Aeroset» analytical complex and solving two independent problems. The first of them is determining the air flow stability in the mine on the whole in the presence of a fire of a given heat emission rate in any place of the mine working. The second task is to find the critical rate of fire heat generation in stationary workings, leading to a loss of stability of the air flow in the mined-out spaces of the mine. The techniques of increasing the speed of calculations of algorithms are studied. The article also describes the developed tools for graphical analysis of the calculation results. Examples of using such tools in practice are given. It is concluded that the developed software tools allow to quickly model the stability of air distribution in the mine ventilation networks of arbitrary topology in the presence of underground fires, and conveniently visualize the calculations.

scholarly journals Wireless Leak Detection System as a Way to Reduce Electricity Consumption in Ventilation Ducts

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3774
Author(s):  
Michał Szelka ◽  
Mariusz Woszczyński ◽  
Jerzy Jagoda ◽  
Paweł Kamiński
Keyword(s):  
Underground Mining ◽  
Detection System ◽  
Ventilation System ◽  
Pressure Sensors ◽  
Electricity Consumption ◽  
Diagnostic System ◽  
Barometric Pressure ◽  
Leak Detection ◽  
Ventilation Network ◽  
Work Related

This article presents a proposal for a wireless diagnostic system for checking the air tightness of the ventilation network. The solution is designed to increase crew safety in underground mining plants and increase the energy efficiency of the ventube ventilation system. The system is based on sensors measuring the pressure inside the ventilation duct in relation to the barometric pressure in the immediate vicinity of the duct. The flow of diagnostic data is based on a cascade transfer. The data from the first sensor are transferred successively to the last one. Based on the prior calibration of alarm thresholds in each device, the leakage or factor influencing the increase of air flow resistance is located. The article presents the genesis of the creation and discusses the principle and purpose of the system. In the following chapters, the progress of work related to testing the system in laboratory, industrial, and underground conditions at the Velenje Premogovnik mine (Slovenia) is presented. The authors analyze the test results and indicate the directions of possible further work on improving the system. The proposed leak detection system is based on a network of pressure sensors that communicate with each other to clearly pinpoint the leak location. The system has been designed for operation in underground mining plants with limited space.

Implications of Person Fluctuation for the Stability and Validity of Test Scores

Methodology ◽  
2006 ◽  
Vol 2 (4) ◽  
pp. 142-148 ◽  
Author(s):  
Pere J. Ferrando
Keyword(s):  
Item Response ◽  
Test Scores ◽  
Temporal Stability ◽  
Person Fit ◽  
Item Parameters ◽  
Individual Trait ◽  
The Stability ◽  
The Individual ◽  
Different Levels ◽  
Fluctuation Model

In the IRT person-fluctuation model, the individual trait levels fluctuate within a single test administration whereas the items have fixed locations. This article studies the relations between the person and item parameters of this model and two central properties of item and test scores: temporal stability and external validity. For temporal stability, formulas are derived for predicting and interpreting item response changes in a test-retest situation on the basis of the individual fluctuations. As for validity, formulas are derived for obtaining disattenuated estimates and for predicting changes in validity in groups with different levels of fluctuation. These latter formulas are related to previous research in the person-fit domain. The results obtained and the relations discussed are illustrated with an empirical example.

Embodying the culture of achievement: Culture between illness and perfection is a ‘thin line’ – obtaining the ideal female body as an act of achievement

2021 ◽  
pp. 1354067X2110040
Author(s):  
Josefine Dilling ◽  
Anders Petersen
Keyword(s):  
Experimental Study ◽  
Human Body ◽  
Female Body ◽  
The Body ◽  
Thin Line ◽  
Complex Processes ◽  
The Individual ◽  
Different Levels ◽  
The Ideal ◽  
Body Ideals

In this article, we argue that certain behaviour connected to the attempt to attain contemporary female body ideals in Denmark can be understood as an act of achievement and, thus, as an embodiment of the culture of achievement, as it is characterised in Præstationssamfundet, written by the Danish sociologist Anders Petersen (2016) Hans Reitzels Forlag . Arguing from cultural psychological and sociological standpoints, this article examines how the human body functions as a mediational tool in different ways from which the individual communicates both moral and aesthetic sociocultural ideals and values. Complex processes of embodiment, we argue, can be described with different levels of internalisation, externalisation and materialisation, where the body functions as a central mediator. Analysing the findings from a qualitative experimental study on contemporary body ideals carried out by the Danish psychologists Josefine Dilling and Maja Trillingsgaard, this article seeks to anchor such theoretical claims in central empirical findings. The main conclusions from the study are used to structure the article and build arguments on how expectations and ideals expressed in an achievement society become embodied.

A Computational Analysis of Flow Field in Twin-Track Subway Tunnel to Improve Air Quality

2013 ◽  
Vol 319 ◽  
pp. 599-604
Author(s):  
Makhsuda Juraeva ◽  
Kyung Jin Ryu ◽  
Sang Hyun Jeong ◽  
Dong Joo Song
Keyword(s):  
Air Quality ◽  
Computational Model ◽  
Stokes Equations ◽  
Ventilation System ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Navier Stokes ◽  
Subway Tunnel ◽  
Air Supply ◽  
And Performance

A computational model of existing Seoul subway tunnelwas analyzed in this research. The computational model was comprised of one natural ventilationshaft, two mechanical ventilationshafts, one mechanical airsupply, a twin-track tunnel, and a train. Understanding the flow pattern of the train-induced airflow in the tunnel was necessary to improve ventilation performance. The research objective wasto improve the air quality in the tunnel by investigating train-induced airflow in the twin-track subway tunnel numerically. The numerical analysis characterized the aerodynamic behavior and performance of the ventilation system by solving three-dimensional turbulent Reynolds-averaged Navier-Stokes equations. ANSYS CFX software was used for the computations. The ventilation and aerodynamic characteristics in the tunnel were investigated by analyzing the mass flowrateat the exits of the ventilation mechanicalshafts. As the train passed the mechanical ventilation shafts, the amount of discharged-air in the ventilationshafts decreased rapidly. The air at the exits of the ventilation shafts was gradually recovered with time, after the train passed the ventilation shafts. The developed mechanical air-supply for discharging dusty air and supplying clean airwas investigated.The computational results showed that the developed mechanical air-supplycould improve the air quality in the tunnel.

scholarly journals Construction Network Ventilation System for Underground LPG Storage Cavern

2018 ◽  
Vol 4 (7) ◽  
pp. 1521 ◽  
Author(s):  
Fang Lin
Keyword(s):  
Ventilation System ◽  
Ventilation Network ◽  
Road Tunnel ◽  
Axial Fan ◽  
Completion Status ◽  
Co Concentration ◽  
Ventilation Technique ◽  
Fluent Software ◽  
Ventilation Performance ◽  
Two Stages

Construction ventilation system is divided into two stages based on completion status of shafts in the underground petroleum storage project in Jinzhou, China. With the help of theoretical analysis and numerical simulations by using FLUENT software, in the first stage, reasonable construction ventilation is designed and cases with different outside temperature are discussed to investigate the effect of ventilation performance. It is found that with temperature difference increases, peak value of CO concentration, exhausting time of dirty air and required time to meet the CO concentration qualification decrease, but the influence degree is quite limited. Gallery-type network ventilation technique (GNVT) refined from theories of operation ventilation for road tunnel and mining ventilation network, is proposed to conduct the second stage construction ventilation. Ventilation performance of different ventilation schemes with various shafts’ states and diverse arrangements of fans are also analyzed in this study. It turns out that Axial-GNVT with shafts taking in fresh air and access tunnel ejecting dirty air has much better performance than traditional forced ventilation from access tunnel. Improved energy saving scheme is finally adopted to guide the construction. In addition, it is worth mentioning that there is no need to build middle ventilation shafts and construct shafts as large and long as possible. Field test of wind speed, dust, poisonous gas, atmospheric pressure, temperature are performed to detect ventilation effectiveness. Reduction coefficient =0.69is obtained from the test results in consideration of super-large section and it also indicates that there is no difference if the axial fan is at the shaft mouth or in the bottom.

CONSTANT AND VARIABLE IN THE STYLE OF A RUSSIAN PIANO QUARTET

2020 ◽  
Vol 1 (2) ◽  
pp. 69-74
Author(s):  
N. K. Samoilova ◽  
Keyword(s):  
Chamber Music ◽  
New Techniques ◽  
Functional Roles ◽  
Russian Music ◽  
Piano Quartet ◽  
Music Making ◽  
The Difference ◽  
The Stability ◽  
Transformation Processes ◽  
Different Levels

The process of the steady rooting of invariant genre features of a piano quartet is considered through the ratio between stable and mobile features. Here there is either the complete independence of the instruments, but on the principles of equal participation in the embodiment of musical content, or the variability in the relations of instrumental parts. As the main ones in the genre, the musical norms of the classic-romantic style and the stability of the timbre composition are established. It is noted that in Russian music the evolution of the piano quartet passed through different phases: genre stabilization and recovery, temporary stop and subsequent active development. Transformation processes went through different levels: structure, content, instrumental- timbre solutions, rethinking the functional roles of partner instruments. The movement from the traditional normativity of instrumental compositions to the difference of timbre combinations in the XXth–XXIst centuries was primarily predetermined by such factors as polyphonization of texture, the active introduction of polyphonic forms, new techniques of instrumentation. In the modern piano quartet, the central idea of chamber music making, the idea of co-creation generates both an extremely individualized form of embodiment and a free timbre composition. In conclusion, it is noted that the piano quartet genre has the ability to accumulate the leading style trends in chamber music of different eras.

Design and Optimization of Air Supply System to Satisfy the Thermal Comfort of Human Body

2021 ◽  
pp. 609-616
Author(s):  
Jue Qu ◽  
Hongjun Xue ◽  
Wei Wang ◽  
Sina Dang ◽  
Xiaoyan Zhang
Keyword(s):  
Thermal Comfort ◽  
Human Body ◽  
Supply System ◽  
Design And Optimization ◽  
Air Supply

scholarly journals Loss of consciousness reduces the stability of brain hubs and the heterogeneity of brain dynamics

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Ane López-González ◽  
Rajanikant Panda ◽  
Adrián Ponce-Alvarez ◽  
Gorka Zamora-López ◽  
Anira Escrichs ◽  
...  
Keyword(s):  
Brain Injuries ◽  
Brain Activity ◽  
Structural Connectivity ◽  
Conscious State ◽  
Brain Dynamics ◽  
Disorder Of Consciousness ◽  
Low Level ◽  
States Of Consciousness ◽  
The Stability ◽  
Different Levels

AbstractLow-level states of consciousness are characterized by disruptions of brain activity that sustain arousal and awareness. Yet, how structural, dynamical, local and network brain properties interplay in the different levels of consciousness is unknown. Here, we study fMRI brain dynamics from patients that suffered brain injuries leading to a disorder of consciousness and from healthy subjects undergoing propofol-induced sedation. We show that pathological and pharmacological low-level states of consciousness display less recurrent, less connected and more segregated synchronization patterns than conscious state. We use whole-brain models built upon healthy and injured structural connectivity to interpret these dynamical effects. We found that low-level states of consciousness were associated with reduced network interactions, together with more homogeneous and more structurally constrained local dynamics. Notably, these changes lead the structural hub regions to lose their stability during low-level states of consciousness, thus attenuating the differences between hubs and non-hubs brain dynamics.

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