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Self-g.azing.SiC-andalusite Refractories for Hig. Temperature g.sification Applications

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China's Refractories 2015年第1期24卷 11-14页

作者： Patrick g.HRE Christos g.ANEZIRIS christopher PARR Institute of Ceramic Glass and Construction MaterialsTechnische Universitat Bergakademie Freiberg Kerneos Neuilly sur Seine 92521France

The combination of SiC and andalusite with calcium aluminate binder for castables in hig. corrosive g.sifying.environments is a promising.alternative refractory system for many different slag.systems. After sintering.a g.assy protective layer has been identified. Beside the interactions of the refractories with intermediate slag.also the thermomechanical properties,the thermal shock performance and the microstructure have been evaluated as a function of different binder systems.

关键词： hig. alumina refractory corrosion by slag.reactive impreg.ation kinetics

Investig.tion of normal,lateral,and oblique impact of microscale projectiles into unidirectional g.ass/epoxy composites

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Defence Technolog.（防务技术） 2022年第11期18卷 1960-1978页

作者： christopher S.Meyer Isabel g.Catug.s John W.g.llespie Jr. Bazle Z.g.ma Haque University of Delaware Center for Composite Materials(UD-CCM) 101 Academy StreetNewarkDE19716USA

Spacesuits and spacecraft must endure hig. velocity impacts from micrometeoroids. This work considers the impact of 100 μm diameter projectiles into composite targ.ts at velocities from 0.5 km/s to 2 km/*** work beg.ns by presenting.an energ.-based theoretical model relating.depth of penetration(Do P)and impact force to impact velocity, characteristic time, and threshold velocity and force. Next, this work compares numerical simulations of normal impact on composites to the theoretical model. Numerical simulations are conducted with LS-DYNA and the well-known composite model, MAT-162. The numerical models consider unidirectional S2-g.ass fiber reinforced SC-15 epoxy composite laminates. The numerical model shows g.od correlation with the theoretical model. The numerical model also investig.tes lateral impact, parallel to the fiber direction, and oblique impact at ang.es from 30°to 82.5°.This work decomposes oblique impact into normal and lateral components, and compares them with normal and lateral impact results. The results show g.od correlation of the normal component of oblique results with the theoretical model. This numerical and theoretical study focuses on Do P, velocity, and penetration resistance force as functions of time. The theoretical model and numerical simulations are used to determine new Do P parameters: characteristic time of depth of penetration and threshold impact velocity. These models are a first step in developing.the capability to predict Do P for oblique,microscale, hig.-speed impact on composite materials.

关键词： Microscale Hypervelocity impact Composites Erosion Penetration

Coal bursts in the deep long.all mines of the United States

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International Journal of Coal Science & Technolog. 2016年第1期3卷 1-9页

作者： christopher Mark U.S. Mine Safety and Health Administration Pittsburgh PAUSA

Coal bursts involve the sudden, violent ejection of coal or rock into the mine working.. They are a particular hazard because they typically occur without warning. During.the past 2 years three US coal miners were killed in two coal bursts, following.a 6-year period during.which there were zero burst fatalities. This paper puts the US experience in the context of worldwide research into coal bursts. It focuses on two major long.all mining.coalfields which have strug.led with bursts for decades. The Utah experience displays many of the ＂classic＂ burst characteristics, including.deep cover, strong.roof and floor rock, and a direct association between bursts and mining.activity. In Colorado, the long.alls of the North Fork Valley （NFV） also work at g.eat depth, but their roof and floor streng.hs are moderate, and most bursts have occurred during.entry development or in headg.tes, bleeders, or other outby locations. The NFV bursts also are more likely to be associated with g.olog.c structures and larg. mag.itude seismic events. The paper provides a detailed case history to illustrate the experience in each of these coalfields. The paper closes with a brief discussion of how US long.alls have manag.d the burst risk.

关键词： Underg.ound mining Coal Burst Long.all Strata control

Computed entropy spectra for g.ain boundary seg.eg.tion in polycrystals

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npj Computational Materials 2024年第1期10卷 2487-2496页

作者： Nutth Tuchinda christopher A.Schuh Department of Materials Science and Eng.neering Massachusetts Institute of Technology77 Massachusetts AvenueCambridgeMA02139USA Department of Materials Science and Eng.neering Northwestern University2145 Sheridan RoadEvanstonIL 60208USA

g.ain boundary solute seg.eg.tion influencesmost bulk material properties,and understanding.solute thermodynamics at g.ain boundaries is critical for eng.neering.***,the vast g.ain boundary space in polycrystals is challeng.ng.to evaluate due to its size,especially for the intrinsically hard-tocompute seg.eg.tion excess *** data science methods are used to g.nerate a database of site-wise g.ain boundary seg.eg.tion entropy spectra for 155 dilute binary alloys within the harmonic *** spectral framework allows scale bridg.ng.between the calculated atomistic sitewise energ.-entropy spectra and macroscopic seg.eg.tion entropy *** results affirm that macroscopic averag.ng.is not sufficient:a spectral treatment of g.ain boundary seg.eg.tion is needed to accurately model bulk temperature dependence of g.ain boundary solute *** calculated spectral entropy database and thermodynamic framework can be applied for both understanding.seg.eg.tion experiments and alloy desig. exercises,paving.the way to a finitetemperature g.ain boundary g.nome.

关键词： g.ain alloy boundary

Parathyroid Adenoma Presenting.as a g.ant Cystic Neck Mass

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International Journal of Otolaryng.log. and Head & Neck Surg.ry 2016年第1期5卷 23-27页

作者： Thomas Muelleman Eric Rosenberg.r Clinton Humphrey christopher g. Larsen Department of Otolaryng.log.—Head and Neck Surg.ry University of Kansas Medical Center Kansas City KS USA Department of Otolaryng.log.—Head and Neck Surg.ry St. Luke’s Hospital Kansas City MO USA

We present a case report of a parathyroid adenoma, which presented as a g.ant cystic neck mass while providing.thoroug. reviews of the pathophysiolog. of parathyroid adenomas and the differential diag.osis for larg., cystic neck masses in adults. A 72 year old female presented to a tertiary academic medical center with a complicated past medical history and was found to have an asymptomatic central neck mass which measured 10.5 × 7.7 × 4.1 cm on ultrasound and extended from the retropharyng.al space with mass effect on the hypopharynx, esophag.s, trachea, and rig.t carotid space structures as well as the superior mediastinum. She had elevated calcium and parathyroid hormone (PTH) levels. She underwent surg.cal excision of this mass and had an uneventful postoperative period. Larg. cystic neck masses g.nerate a wide differential diag.osis. In adults, it is important to consider the rare possibility of parathyroid adenoma, especially in patients who may not be able to communicate vag.e symptoms of hypercalcemia. This particular parathyroid adenoma is several orders of mag.itude larg.r than an averag. parathyroid adenoma and its massive size served as a distraction for the proper diag.osis as larg., cystic neck masses in adults are to be considered cancer until proven otherwise.

关键词： Parathyroid Adenoma g.ant Parathyroid Adenoma Larg. Cystic Neck Mass Hypercalcemia

Associations between aerobic and muscle-streng.hening.physical activity,sleep duration,and risk of all-cause mortality:A prospective cohort study of 282,473 ***

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Journal of Sport and Health Science 2023年第1期12卷 65-72页

作者： Mitch J.Duncan Stina Oftedal christopher E Kline Ronald C.Plotnikoff Elizabeth g.Holliday School of Medicine&Public Health College of HealthMedicineand WellbeingThe University of NewcastleCallaghanNSW 2308Australia Priority Research Centre for Physical Activity and Nutrition The University of NewcastleCallaghanNSW 2308Australia Department of Health&Human Development The University of PittsburghPittsburghPA 15261USA School of Education University of NewcastleCallaghanNSW 2308Australia

Purpose:To examine the joint associations between meeting.g.idelines for physical activity(PA)and sleep duration and all-cause mortality risk among.***:Participants were adults(n=282,473)ag.d 18-84 years who participated in the 2004-2014 *** Health Interview *** status was ascertained using.the National Death Index throug. December ***-reported PA(Active:meeting.both aerobic(AER)and muscle-streng.hening.MSA)g.idelines,AER only(AER),MSA only(MSA),or not meeting.either AER or MSA(Inactive))and sleep duration(Short,recommended(Rec),or Long.were classified according.to g.idelines,and 12 PA-sleep categ.ries were *** hazard ratios and 95%confidence intervals(95%CIs)for all-cause mortality risk were estimated using.Cox proportional hazards reg.ession ***:A total of 282,473 participants(55%females)were included;18,793 deaths(6.7%)occurred over an averag. follow-up of 5.4 *** to the Active-Rec g.oup,all other PA-sleep g.oups were associated with increased mortality risk except for the Active-Short g.oup(hazard ratio=1.08;95%CI:0.92-1.26).The combination of long.sleep with either MSA or Inactive appeared to be *** a g.ven sleep duration,mortality risk prog.essively increased among.participants classified as AER,MSA,and *** each activity level,the mortality risk was g.eatest among.adults with long.***:Relative to adults meeting.g.idelines for both PA and sleep duration,adults who failed to meet g.idelines for both AER and muscle streng.hening.PA and who also failed to meet sleep duration g.idelines had elevated all-cause mortality *** results support interventions targ.ting.both PA and sleep duration to reduce mortality risk.

关键词： Activity-sleep patterns All-cause mortality Prospective Resistance training

Waterbird use of farm dams in south-eastern Australia:abundance and influence of biophysical and landscape characteristics

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Chinese Birds 2017年第1期8卷 12-24页

作者： Andrew J.Hamilton ChloéConort Aurore Bueno christopher g.Murray James R.g.ove Faculty of Veterinary and Ag.icultural Sciences The University of MelbourneDookie CampusCurrawaVIC 3647Australia Office of the Deputy Vice-Chancellor(Research and Innovation) Federation University AustraliaBallaratVIC 3353Australia Department of Rural Health Melbourne Medical School49 Graham StreetPO Box 6500SheppartonVIC 3632Australia École Nationale Supérieure Ag.onomique de Toulouse 31326 Castanet TolosanFrance Faculty of Science The University of MelbourneParkvilleVIC 3010Australia Faculty of Science Department of GeographyThe University of MelbourneParkvilleVIC 3010Australia

Backg.ound: While ag.iculture has taken much environmental water in Australia's Murray-Darling.Basin, ag.icultural expansion has resulted in a vast number of farm dams, almost three-quarters of a million in the Murray-Darling.Basin ***: Over a summer we studied(1) waterbird abundance and species richness and(2) the influence of biophysical and landscape characteristics across 49 farm dams at a larg. mixed-enterprise farm in northern Victoria on the southern reach of the Murray-Darling.***: On averag., dams were found to host 27.1 ± 71.1 individuals/ha and 1.8 ± 2.9 species per pond. Such densities are comparable to those on natural wetlands. Dam surface area and perimeter and amount of veg.tation were positively and strong.y correlated with the Rallidae density(birds/ha), but no other parameters were strong.y correlated with any other functional g.oup. The landscape in which the dams were embedded had a hig.ly sig.ificant effect(p g.ven at our site they supported similar densities of individuals and species to natural wetlands, and g.ven the fact that there are 710,539 farm dams in the Murray-Darling.Basin, which hosts much of Australia's waterbird fauna, it is reasonable to sug.est that farm dams are overlooked, and possibly very important, avian biodiversity hotspots. It also hig.lig.ts the importance of a landscape setting. in which dams are situated, on the number of birds using.the dams.

关键词： Farm ponds Waterbirds Waterfowl Zooplankton

CO_(2)Plume g.othermal(CPg.Systems for Combined Heat and Power Production:an Evaluation of Various Plant Config.rations

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Journal of Thermal Science 2022年第5期31卷 1266-1278页

作者： SCHIFFLECHNER christopher WIELAND Christoph SPLIETHOFF Hartmut Chair of Energ. Systems TUM School of Engineering and DesignTechnical University of Munich85747 GarchingGermany

CO_(2) Plume g.othermal(CPg.systems are a promising.concept for utilising.petrothermal resources in the context of a future carbon capture utilisation and sequestration *** g.othermal energ. has a tremendous worldwide potential for decarbonising.both the power and heating.*** paper investig.tes three potential CPg.config.rations for combined heating.and power g.neration(CHP).The present work examines scenarios with reservoir depths of 4 km and 5 km,as well as required district heating.system(DHS)supply temperatures of 70℃ and 90℃.The results reveal that a two-stag.d serial CHP concept eventuates in the hig.est achievable net power *** a thermosiphon system,the relative net power reduction by the CHP option compared with a sole power g.neration system is sig.ificantly lower than for a pumped *** net power reduction for pumped systems lies between 62.6%and 22.9%.For a thermosiphon system with a depth of 5 km and a required DHS supply temperature of 70℃,the achievable net power by the most beneficial CHP option is even 9.2%hig.er than for sole power g.neration *** second law efficiency for the sole power g.neration concepts are in a rang. between 33.0%and 43.0%.The second law efficiency can increase up to 63.0%in the case of a CHP ***,the combined heat and power g.neration can sig.ificantly increase the overall second law efficiency of a CPg.*** evaluation of the achievable revenues demonstrates that a CHP application mig.t improve the economic performance of both thermosiphon and pumped CPg.***,the minimum heat revenue required for compensating.the power reduction increases with hig.er electricity *** summary,the results of this work provide valuable insig.ts for the potential development of CPg.systems for CHP applications and their economic feasibility.

关键词： deep g.othermal energ. combined heat and power g.neration CO_(2)plume g.othermal systems petrothermal resources carbon capture utilisation and storag.

Assessing.risks from mining.induced g.ound movements near g.s wells

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International Journal of Mining.Science and Technolog. 2020年第1期30卷 11-16页

作者： christopher Mark g.eg.ry M.Rumbaug. Mine Safety and Health Administration PittsburghPAUSA

The proliferation of unconventional g.s well development in the Northern Appalachian coalfields has raised a number of mine safety *** wells,which extract g.s from deep shale formations,are characterized by g.s volumes and pressures that are sig.ificantly hig.er than those observed at many conventional *** g.s is composed larg.ly of methane as well as other *** of planned and actively producing.wells penetrate protective coal pillars or barriers within active mine boundaries,including.chain pillars located between long.all *** released from a well damag.d by mining.induced g.ound movements could pose a risk to miners by flowing.into the mine *** mining.induced g.ound movements that may cause well damag. include conventional subsidence,non-conventional subsidence(*** plane slip),pillar failure,and floor *** paper describes the known risk factors for each of the four failure *** includes a framework that can g.ide the risk assessment process when mining.takes place near g.s or oil wells.

关键词： g.s well Subsidence Coal protection pillar Risk matrix Long.all mining