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Influence of varying bedding thickness of underclay on floor stability

International Journal of Mining Science and Technology 2017年第3期27卷 517-523页

作者： Jessu Kashi Vishwanath Kostecki Todd ray Spearing Anthony John spencer Zhang Jixiong Western Australia School of Mines Curtin University Kalgoorlie 6430 Australia Southern Illinois University Carhondale 62901 USA The State Key Laboratory of Coal resources and Safe Mining China University of Mining & Technology Xuzhou 221116 China

The variation in bedding thickness of the weak immediate floor has long been a challenge in the lllinois basin coal mines when it comes to floor stability. The vertical thickness of the immediate floor is not constant throughout the mines and can vary over short horizontal distances. The biggest misconception from a design standpoint is to use the maximum or average thickness found from core logs taken from various locations on the mine property. The result of this practice is oversized pillars in the areas where the weak immediate floor has thinned vertically. This over-design leaves coal in situ which could have otherwise been extracted. This paper presents a plane strain numerical model to illustrate the effect of a change in bedding thickness of a weak immediate floor across one or two coal pillars. The floor bearing capacity of the variable floor below each pillar where then compared to the consistent floor. The results show that the varying bedding thickness of weak underclay has an impact on the bearing capacity of the floor. geometrically with the decrease in bedding thickness for constant pillar width, the B/H ratio increases exponentially. The influence of varying bedding thickness on the floor bearing capacity is apparent at higher B/H ratios. The floor bearing capacity under a single pillar is in variable floor model if the average thickness remains constant. For single pillar, the average of the bedding thickness can be considered and for pillars in a panel, and a safety factor has been proposed to take into account this change in bedding thickness.

关键词： Bedding thickness klnderclay Fireclay Illinois Basin Floor bearing capacity Floor safety factor

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Technical and conceptual considerations forusing animated stimuli in studies of animalbehavior

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Current Zoology 2017年第1期63卷 5-19页

作者： Laura CHOUINArD-THULY Stefanie gIErSZEWSKI gil g. rOSENTHAL Simon M. rEADEr guillaume rIEUCAU Kevin L. Woo robert gErLAI Cynthia TEDOrE spencer J. INgLEY John r. STOWErS Joachim g.FrOMMENI Francine L. DOLINS Klaudia WITTE Department of Biologv McGill University 1205 Docteur Penfield Montreal Quebec Canada H3A 1B1 research group of Ecology and Behavioral Biology Institute of Biology University of Siegen Adolf-Reichwein Str. 2 Siegen 57068 Germany Ecology & Evolutionary Biology Texas A&M University 3258 TAMU College Station TX 77843 USA Centro de Investigaciones Cientfficas de las Huastecas "Aguazarca" Calnali Hidalgo Mexico Departmentof Biological Sciences Florida International University 3000 Northeast 151 Street North Miami FL 33181 USA SUNY Empire State College Metropolitan Center 325 Hudson Street New York NY 10013-1005 USA Departmentof Psychology University of Toronto Mississauga 3359 Mississauga Road Mississauga Ontario Canada L5L 1C6 Lund Vision group Department of Biology Lund University SSIvegatan 35 Lund 22362 Sweden Department of Biology University of North Carolina at Chapel Hill CB#3280 Coker Hall Chapel Hill NC 27599 USA research Institute of Molecular Pathology IMP Vienna Biocenter VBC Dr. Bohr-Gasse 7 Vienna 1030 Austria loopbiogmbh Hauptstrasse 93 Kritzendorf 3420 Austria Department of Behavioural Ecology Institute of Ecology and Evolution University of Bern Wohlenstrasse 50a Hinterkappelen 3032 Switzerland Department of Behavioral Sciences University of Michigan-Dearborn 4901 Evergreen Road Dearborn MI 48128 USA

rapid technical advances in the field of computeropened new avenues in animal behavior *** （CA） and virtual reality （Vr） haveAnimated stimuli are powerful tools as theyoffer standardization, repeatability, and complete control over the stimulus presented, thereby＂reducing＂ and ＂replacing＂ the animals used, and ＂refining＂ the experimental design in line withthe 3rs. However, appropriate use of these technologies raises conceptual and technical *** this review, we offer guidelines for common technical and conceptual considerations related tothe use of animated stimuli in animal behavior research. Following the steps required to create ananimated stimulus, we discuss （I） the creation, （11） the presentation, and （111） the validation of CAsand Vrs. Although our review is geared toward computer-graphically designed stimuli, consider-ations on presentation and validation also apply to video playbacks. CA and Vr allow both new be-havioral questions to be addressed and existing questions to be addressed in new ways, thus weexpect a rich future for these methods in both ultimate and proximate studies of animal behavior.

关键词： animal behavior, animated stimulus, computer animation, experimental design, virtual reality, visual communication.

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Prediction of Dynamic and Aerodynamic Characteristics of the Centrifugal Fan with Forward Curved Blades

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Journal of Thermal Science 2013年第6期22卷 517-521页

作者： Jií Polansky László Kalmár roman gápár Univerzitní 8 306 14 PlzeňCzech Republic Miskolc-Egyetemváros MiskolcHungary

The main aim of this paper is determine the centrifugal fan with forward curved blades aerodynamic characteristics based on numerical modeling. Three variants of geometry were investigated. The first, basic "A" variant contains 12 blades. The geometry of second "B" variant contains 12 blades and 12 semi-blades with optimal length[1]. The third, control variant "C" contains 24 blades without semi-blades. Numerical calculations were performed by CFD Ansys. Another aim of this paper is to compare results of the numerical simulation with results of approximate numerical procedure. Applied approximate numerical procedure [2] is designated to determine characteristics of the turbulent flow in the bladed space of a centrifugal-flow fan impeller. This numerical method is an extension of the hydro-dynamical cascade theory for incompressible and inviscid fluid flow. Paper also partially compares results from the numerical simulation and results from the experimental investigation. Acoustic phenomena observed during experiment, during numerical simulation manifested as deterioration of the calculation stability, residuals oscillation and thus also as a flow field oscillation. Pressure pulsations are evaluated by using frequency analysis for each variant and working condition.

关键词： Centrifugal Fan CFD Pressure Coefficient Flow Coefficient

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CAVITATION INCEPTION IN TUrBULENT SHEAr LAYErS

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Journal of Hydrodynamics 1991年第4期3卷 109-117页

作者： r.Leucker r.Mohn g.rouvé Institute for Hydraulic Engineering and Water resources Development(IWW) Aachen University of Technology(RWTH)Mies-van-der-Rohe-Str.1W-5100 AachenGermany

In this paper the extensive calibration procedure of a hybrid model for predicting cavitation inception in free shear layers *** hybrid model treats the cavitation process as two decoupled processes,a hydrodynamic one and a bubble dynamic *** hydrodynamic part is modeled by a small-scale physical model,whereas the bubble dynamic part is solved *** a short explanation of the hybrid model,the procedure of fixing the free parameters of the mathematical formulation by given(measured)data from diverse test facilities is explained.

关键词： CAVITATION INCEPTION IN TUrBULENT SHEAr LAYErS

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Primary Contacts Identification for COVID-19 Carriers from Surveillance Videos

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Computer Systems Science & Engineering 2022年第12期43卷 947-965页

作者： r.Haripriya g.Kousalya Department of Computer Science and Engineering Coimbatore Institute of TechnologyCoimbatore641014India

COVID-19 (Coronavirus disease of 2019) is caused by SArS-CoV2(Severe Acute respiratory Syndrome Coronavirus 2) and it was first diagnosedin December 2019 in China. As of 25th Aug 2021, there are 165 million con-firmed COVID-19 positive cases and 4.4 million deaths globally. As of today,though there are approved COVID-19 vaccine candidates only 4 billion doseshave been administered. Until 100% of the population is safe, no one is safe. Eventhough these vaccines can provide protection against getting seriously ill anddying from the disease, it does not provide 100% protection from getting infectedand passing it on to others. The more the virus spreads;it has more opportunity tomutate. So, it is mandatory to follow all precautions like maintaining social distance, wearing mask, washing hands frequently irrespective of whether a person isvaccinated or not. To prevent spread of the virus, contact tracing based on socialdistance also becomes equally important. The work proposes a solution that canhelp with contact tracing/identification, knowing the infected persons recent travelhistory (even within the city) for few days before being assessed positive. Whilethe person would be able to give the known contacts with whom he/she has interacted with, he/she will not be aware of who all were in proximity if he/she hadbeen in public places. The proposed solution is to get the CCTV (Closed-CircuitTelevision) video clips from those public places for the specific date and time andidentify the people who were in proximity—i.e., not followed the safe distance tothe infected person. The approach uses YOLO V3 (You Only Look Once) whichuses darknet framework for people detection. Once the infected person is locatedfrom the video frames, the distance from that person to the other people in theframe is found, to check if there is a violation of social distance guideline. If thereis, then the people violating the distance are extracted and identified using Facialdetection and recognitio

关键词： COVID-19 social distancing object detection facial detection facial recognition contact tracing artificial intelligence

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Structural, optical and electron paramagnetic resonance studies on Cu-doped ZnO nanoparticles synthesized using a novel auto-combustion method

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Frontiers of Materials Science 2013年第2期7卷 196-201页

作者： r. ELILArASSI g. CHANDrASEKArAN Magnetism and Nanomagnetic Materials Lab Department of Physics School of Physical Chemical and Applied Sciences Pondicherry University Puducherry 605014 India

Nanocrystalline Zn1_xCuxO （x = 0, 0.02, 0.04, 0.06, 0.08） samples were synthesized by a novel auto-combustion method using glycine as the fuel material. The structural, optical and magnetic properties of the samples were characterized using XrD, SEM, photoluminescence （PL） and electron paramagnetic resonance （EPr） spectro- scopies. The XrD spectra of samples reveal the hexagonal wurtzite structures of ZnO. As the copper content increases, a diffraction peak at 28 = 39° corresponding to secondary phase of CuO （[111] crystalline face） appears when x≤ 6 mol.%. PL spectra of the samples show a strong ultraviolet （UV） emission and defect related visible emissions. Cu-doping in ZnO can effectively adjust the energy level in ZnO, which leads to red shift in the emission peak position in UV region. The EPr spectra of Cu-doped ZnO nanoparticles show a distinct and broad signal at room temperature, suggesting that it may be attributed to the exchange interactions within Cu2＋ ions.

关键词： Cu-doped ZnO auto-combustion luminescence electron paramagneticresonance (EPr)

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SIMULATION OF COMPLEX THErMOMECHANICAL FATIgUE

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 400-406页

作者： r.Bardenheier g.rogers Instron Ltd. Servohydraulic Business Team High Wycombe HP12 3SY United KingdomInstron Ltd. Servohydraulic Business Team High Wycombe HP12 3SY United Kingdom

Two different types of experimental techniques to perform non-isothermal, uniax-ial and biaxial fatigue tests were described. A new miniaturised electrothermal-mechanical test rig was presented and discussed. It enables testing of small specimens under complex thermomechanical loading conditions. In order to cope with the simulation of well defined biaxial proportional and non-proportional loadings with in-phase and out-of-phase superposition of thermal loads a cruciform biaxial fatigue testing machine has been developed. Special design features of both machines, and the specimens tested, as well as typical test results were discussed.

关键词： thermomechanical fatigue biaxial loading non-proportional loading cruciform fatigue testing machine miniaturised test rig

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怀念伯奇·步林(1898—1990)

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古脊椎动物学报(中英文） 1993年第1期 74-75页

作者： spencer g. Lucas

瑞典著名古生物学家步林博士1990年在瑞典乌普萨拉病逝。他是本世纪二三十年代开创中国地质古生物学事业的一批杰出学者中最后离开我们的一位,这批学者还包括安特生、魏曼和斯丹斯基。 1927年,在魏曼的指导下,二十九岁的步林完成了研究... 详细信息

瑞典著名古生物学家步林博士1990年在瑞典乌普萨拉病逝。他是本世纪二三十年代开创中国地质古生物学事业的一批杰出学者中最后离开我们的一位,这批学者还包括安特生、魏曼和斯丹斯基。 1927年,在魏曼的指导下,二十九岁的步林完成了研究中国长颈鹿化石的博士论文。

关键词：古生物学家瑞典北欧中华人民共和国化石脊椎动物

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TrANSFOrMATIVE rENEWAL AND UrBAN SUSTAINABILITY

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Journal of green Building 2013年第4期8卷 17-38页

作者： Susan spencer Lewin Craig goodman OAA LEED BD+C

A key tenet of sustainable urban development is adaptive reuse, which is the practice of reusing existing infrastructure for a purpose other than for what it was built. Communities have much to gain from the adaptive reuse and transformative renewal of the older built fabric of the city. retaining older buildings has environmental benefits as it bypasses complete demolition and reconstruction, and conserves the considerable embodied energy stored within the structure. Adaptive reuse is a key environmental factor in land conservation and the reduction of urban sprawl, as it promotes the reuse and revitalization of downtown and inner city sites. Existing buildings highlight the social character and identity of a community through the retention of the irreplaceable historic fabric. Existing buildings promote a strong and vibrant sense of place, leading to increased citizen engagement. Economic benefits can follow as the adaptive reuse and revitalization creates renewal, new uses, and captures the value of the existing building stock, creating a spur to the local economy. For these reasons, the adaptive reuse of existing and historic buildings is an essential component of sustainable urban development. This article will review a case study of the new downtown campus for the University of Windsor and the use of three existing historic buildings as a relevant adaptive reuse strategy toward inner city regeneration and revitalization. The overall strategy for urban sustainability will be reviewed, as well as specific issues and opportunities for each of the three projects.

关键词： University campus renewal city revitalization transformative renewal adaptive re-use sustainable urban design public realm design catalyst site heritage reuse

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怀念师丹斯基

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古脊椎动物学报(中英文） 1991年第1期 82-83页

作者： spencer g.Lucas

著名的奥地利古生物学家师丹斯基教授,不幸于1988年12月26日在瑞典乌普萨拉病逝,享年94岁.师丹斯基教授一生致力于科学研究,在古哺乳动物学领域中取得了重大成就.他与中国古脊椎动物与古人类学研究有着长期的、密切的关系.从1921年夏至1... 详细信息

著名的奥地利古生物学家师丹斯基教授,不幸于1988年12月26日在瑞典乌普萨拉病逝,享年94岁.师丹斯基教授一生致力于科学研究,在古哺乳动物学领域中取得了重大成就.他与中国古脊椎动物与古人类学研究有着长期的、密切的关系.从1921年夏至1923年底,他随中瑞古生物考察团在中国做了大量的化石采集工作,之后陆续在《中国古生物志》上发表了多篇专著,其中包括:中国第三纪后期之食肉类化石(1924);中国北部第四纪之食肉类化石(1925);中国的鹿类化石(1925);河南渑池县之古骆驼类化石(1926);中国食肉类化石新发现之特征(1927);周口店第四纪之哺乳类化石(1928);中国早第三纪哺乳类化石(1930);马及其它奇蹄类(1935).在这些论文中,不仅记述了化石,而且有新见,为进一步研究中国这些门类的化石奠定了良好的基础.此外,他还在北京周口店发现过古人类化石.师丹斯基教授的逝世,无疑是古生物学界的一大损失,不仅中国同行,国外朋友也都缅怀他.

关键词：化石哺乳类古生物中华人民共和国食肉类周口店丹斯

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