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Empirical-analytical method for evaluating the pressure distribution in the hard coal seams

Mining Science and Technology 2009年第5期19卷 556-562页

作者： kabiesz józef MAKóWKA janusz Central Mining Institute Katowice 40-166 Poland

At present, numerical modelling of distributions of many rock mass characteristics plays more and more important role in many geomechanical questions. In the issues related to seismic and rockburst hazards, the analyses of distributions of stress component values in the rock strata are performed, similarly as those of deformation parameters of the strata. To do this, commercial computer programs are used which function on the basis of the finite element-, separate element-, finite difference-, boundary element methods, or individually designed computer programs. They enable to obtain information, unattainable with other methods, being of importance for further concluding on those hazards. The programs based on applying those methods have contributed to important progress and development of science in the domain of analyzing and predicting the hazards. To this end, the commercial computer programs are used that are based on the methods of: finite elements, separate elements, finite differences, boundary elements, etc., or on individually developed computer programs. They enable to obtain information, unavailable using other methods, being of vital importance for further concluding on these hazards. The programs based on these methods have contributed to essential progress and development of science in the field of analysing and predicting the hazards. Apart from their obvious advantages, they have many drawbacks that hinder their practical, routine application. To allow making these type of analyses, without the necessity of constructing complicated models and knowing the detailed geomechanical parameters of rocks, together with laborious computation using a high-rank computer hardware, an analytical-empirical method has been developed at Central Mining Institute, Poland, to make prediction (modelling) of the distribution of pressure values (vertical component of stress) in SIGMAZ coal seams. It is based on geophysical measurements, generalized for the conditions of

关键词： hard coal mine stress value modelling distribution of pressure

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Selected elements of rock burst state assessment in case studies from the Silesian hard coal mines

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Mining Science and Technology 2009年第5期19卷 660-667页

作者： kabiesz józef MAKóWKA janusz Central Mining Institute

Exploitation of coal seams in the Upper Silesian Coal Basin is conducted in complex and difficult conditions. These difficulties are connected with the occurrence of many natural mining hazards and limitations resulting from the existing in this area surface infrastructure. One of the most important problems of Polish mining is the rock burst hazard and reliable evaluation of its condition. During long-years’ mining practice in Poland a comprehensive system of evaluation and control of this hazard was developed. In the paper the main aspects of rock burst hazard state evaluation will be presented, comprising: 1) rock mass inclination for rock bursts, i.e., rock strength properties investigation, comprehensive parametric evaluation of rock mass inclination for rock bursts, prognosis of seismic events induced by mining operations, methods of computer-aided modelling of stress and rock mass deformation parameters distribution, strategic rock mass classification under rock burst degrees; 2) immediate seismic and rock burst hazard state evaluation, i.e., low diameter test drilling method, seismologic and seismoacoustic method, comprehensive method of rock burst hazard state evaluation, non-standard methods of evaluation; 3) legal aspects of rock burst hazard state evaluation. Selected elements of the hazard state evaluation system are illustrated with specific practical examples of their application.

关键词： coal mine rock bursts control case studies

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Scale of seismic and rock burst hazard in the Silesian companies in Poland

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Mining Science and Technology 2009年第5期19卷 604-608页

作者： PATY■SKA Renata kabiesz józef Central Mining Institute

Presently the seismic and rock burst hazard appears still to be important in most of hard coal mines in Poland. Recently, there was a significant increase of seismic activity of the Silesian rock massive, when compared with the previous years. In the period 1999-2008 the hard coal mines experienced 34 rock bursts. The causes of rockburst occurrence are presented based on the analysis of the rockbursts occurring in the Polish hard coal mines. The scale of the rockburst hazard has been characterized with respect to the mining and geological conditions of the existing exploitation. Of the factors influencing the state of rockburst hazard, the most essential one is considered the depth interval ranging from 600 m to 900 m. The basic factors that promote the rockburst occurrence are as follows： seismogenic strata, edges and remnants, goal, faults, pillars and excessive paneling.

关键词： rockbursts mining and geological conditions

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Energy and blast performance of beryllium in a model thermobaric composition in comparison with aluminum and magnesium

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Defence Technology（防务技术） 2024年第6期36卷 13-19页

作者： Thomas M.Klapotke Stanisław Cudziło Waldemar A.Trzcinski jozef Paszula Energetic Materials Research Department of ChemistryUniversity of Munich(LMU)Butenandtstrasse 5-13(D)81377MunichGermany Military University of Technology Faculty of Advanced Technologies and ChemistrySylwester Kaliski Str.200-908WarsawPoland

A direct comparison is made between the effectiveness of Al,Mg,and Be powders as additional fuels in model thermobaric compositions containing 20%fuel,20%ammonium perchlorate,and 60%RDX(1,3,5-Trinitro-1,3,5-triazacyclohexane)passivated with *** determined calorimetric measurements of the heat of detonation,along with the overpressure histories in an explosion chamber filled with nitrogen,were used to determine the quasi-static pressure(QSP)under anaerobic *** measurements were also performed in a semi-closed bunker,and all blast wave parameters generated after the detonation of 500 g charges of the tested explosives were *** calorimetry results,QSP values,and blast wave parameters(pressure amplitude,specific and total impulses)clearly indicate that Be is much more effective as an additional fuel than either Al or Mg in both anaerobic post-detonation reactions as well as the subsequent aerobic *** heat of detonation of the RDXwax/AP/Be explosive mixture is over 40%and 50%higher than that of the mixture containing aluminum and magnesium instead of beryllium,***,the TNT equivalent of the Be-containing composition due to the overpressure in the nitrogen-filled explosion chamber is 1.66,while the equivalent calculated using an air shock wave-specific impulse at a distance of 2.5 m is equal to *** high values of these parameters confirm the high reactivity of beryllium in both the anaerobic and aerobic stages of the thermobaric explosion.

关键词： Thermobaric explosives Beryllium Heat of detonation Quasi-static overpressure Blast wave parameters

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Performance analysis of IEEE 802.11 DCF networks

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journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第10期9卷 1309-1317页

作者： Krzysztof SZCZYPIORSKI józef LUBACZ Institute of Telecommunications Warsaw University of Technology Nowowiejska 15/19 Warsaw 00-665 Poland

This paper presents an analytical saturation throughput model of IEEE 802.11 DCF (distributed coordination function) with basic access in ad hoc mode. The model takes into account freezing of the backoff timer when a station senses busy channel. It is shown that taking into account this feature of DCF is important in modeling saturation throughput by yielding more accurate and realistic results than models known from literature. The proposed analytical model also takes into account the effect of transmission errors. All essential features of the proposed analytical approach are illustrated with numerical results. The presen-tation of the model is proceeded by an overview of approaches to IEEE 802.11 network performance evaluation presented in the literature.

关键词： IEEE 802.11 Distributed coordination function (DCF) CSMA/CA Modeling

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Fault Detection under Fuzzy Model Uncertainty

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International journal of Automation and computing 2007年第2期4卷 117-124页

作者： Marek Kowal józef Korbicz Institute of Control and Computation Engineering University of Zielona Góraul. Podgórna 5065-246 Zielona GóraPoland

The paper tackles the problem of robust fault detection using Takagi-Sugeno fuzzy models. A model-based strategy is employed to generate residuals in order to make a decision about the state of the process. Unfortunately, such a method is corrupted by model uncertainty due to the fact that in real applications there exists a model-reality mismatch. In order to ensure reliable fault detection the adaptive threshold technique is used to deal with the mentioned problem. The paper focuses also on fuzzy model design procedure. The bounded-error approach is applied to generating the rules for the model using available measurements. The proposed approach is applied to fault detection in the DC laboratory engine.

关键词： Fault diagnosis fuzzy systems uncertainty noise.

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Comprehensive use of the Gutenberg–Richter law and geotomography for improving seismic hazard evaluation in hard coal mines

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International journal of Coal Science & Technology 2023年第1期10卷 48-59页

作者： józef Dubiński Krystyna Stec jacek Krupanek Central Mining Institute 40-166 KatowicePoland Polish Mining Group Ltd. Mine MysłowiceWesołaPoland

Mining-induced seismicity occurs in numerous underground mines worldwide where extraction is conducted at great depths or in areas characterised by complex tectonic *** is accompanied by rock bursts,which result in the loss of working functionality and the possibility of accidents among *** issue of a constant and reliable seismic hazard evaluation is of key signifcance for both the safety of miners and the stability of *** on its improvement is directed at developing new interpretive solutions and *** nature of the presented solution is the complex interpretation of seismological data that characterise rock mass seismicity and of underground measurement results in the form of a map presenting the longitudinal wave propagation velocity distribution in the rock surrounding the mined coal *** solution was tested in hard coal mines located in the Upper Silesian Coal *** mines are equipped with a modern seismological system enabling the constant monitoring of seismicity together with hazard level evaluation as well as with seismic apparatus for conducting periodic measurements of the seismic wave propagation velocity before the mining *** seismic hazard evaluation criteria were determined based on the obtained results,involving the anomaly of the Gutenberg–Richter law“b”value and the maximum longitudinal seismic wave propagation velocity in the roof *** obtained experience and the result validation of this new comprehensive hazard evaluation method confrm its practical usefulness and indicate the directions of improvement for the solution in question.

关键词： Induced seismicity Rock bursts Mine seismology Gutenberg-Richter law Seismic geotomography

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Chromized Layers Produced on Steel Surface by Means of CVD

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材料热处理学报 2004年第5B期25卷 807-809页

作者： KASPRZYCKA Ewa BOGDA■SKI Bogdan jEZIORSKI Leopold jASI■SKI józef TORBUS Roman Institute of Precision Mechanics Warsaw PolandInstitute of Precision Mechanics Warsaw PolandInstitute of Materials Engineering Czestochowa University of Technology PolandInstitute of Materials Engineering Czestochowa University of Technology PolandInstitute of Materials Engineering Czestochowa University of Technology Poland

Chemical vapour deposition of chromium on the surface of carbon steel has been investigated using a novel CVD method that combines the low cost of pack cementation method with advantages of vacuum technique. The processes have been performed in chromium chlorides atmosphere at a low pressure range from 1 to 800 hPa, the treatment temperature 800 to 950°C. Studies of the layers thickness, the phase composition, Cr, C and Fe depth profiles in diffusion zone have been conducted. The effect of the vacuum level during the process and the process parameters such as time and temperature on layer diffusion growth on the carbon steel surface has been investigated.

关键词：扩散层热化学处理扩散镀铬碳化物层 CVD

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Importance of physical and functional properties of foods targeted to seniors

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journal of Future Foods 2021年第2期1卷 146-155页

作者： józef Grochowicz Anna Fabisiak Adam Ekielski Department of Food Engineering University of Life SciencesLublin 20-036Poland Social and Medical University Warsaw 04-367Poland Department of Production Engineering Warsaw University of Life SciencesWarsaw 02-787Poland

The paper presents nutritional problems of elderly people from an international perspective,due to the diversity of nutritional *** acceptance and readiness to purchase functional foods by consumers has been widely studied,but no studies have been conducted on the attitude of older consumers to innovative products with health *** perception of functional food by the elderly and the analysis of factors determining the purchase of food that improves health are of great *** fi rst part of the study provides an overview of functional products available on the market,against a background of diverse nutritional needs of older *** the second part of the study,the opinion of seniors on the role and place of special food for older people in their diet,as well as possibilities and limitations were *** shows that the market for older consumers is not homogeneous,because the reasoning of health and health determinants is *** is a group of consumers,which are looking for healthy *** are also critical and cautious consumers and consumers of natural *** themes and barriers to the use of products with health claims have been identifi ed and described.

关键词： Functional food Nutition Older people

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Low-Carbon,Mn-Si Cast Steel Structure Modification by Fluidized Bed Heat Treatment

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journal of Iron and Steel Research International 2011年第S1期18卷 541-545页

作者： jasiński józef Podsiad Piotr jasiński jaroslaw Bul Arnold Kaczmarczyk Andrzej Czestochowa University of Technology Materials Science InstituteArmii Krajowej Av.1942-200 CzestochowaPoland HSW Stalowa Wola E.Kwiatkowskiego St.137-450 Stalowa WolaPoland

The effect of fluidized bed heat treatment (FBHT) on low-carbon Mn-Si cast steel strength properties improvement,strictly ductility is shown in this *** bed heat treatment variants are chosen in order to eliminate the structure defaults after a crystallization *** parameters are set considering an initial state material chemical composition,structure morphology and application criterion after heat *** results are verified according with the standard BS 3100:1991 *** bed heat treatment variants are chosen mainly in order to the Widmanst tten ferrite structures elimination,carbides morphology modification and matrix optimum performance properties *** ZG35SiMn (EN:L30GS) FBHT processes results are verified by the metallographic researches,hardness/microhardness measurements and tensile strength examination.

关键词： cast steel heat treatment modification fluidized bed

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