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Design concerns of room.and pillar retreat panels

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International Journal of m.ning Science and Technology 2017年第1期27卷 29-35页

作者： Klem.tti Ted m. Sears morgan m. Tulu Ihsan B. m.ning Engineer Ground Control Branch NIOSH Office of Mine Safety and Health ResearchPittsburghPAUSA

Why do som. room.and pillar retreat panels encounter abnorm.l conditions？ What factors deserve the m.st consideration during the planning and execution phases of m.ning and what can be done to m.tigate those abnorm.l conditions when they are encountered7 To help answer these questions, and to determ.ne som. of the relevant factors influencing the conditions of room.and pillar （R ＆ P） retreat m.n- ing entries, four consecutive R ＆ P retreat panels were evaluated. This evaluation was intended to rein- force the influence of topographic changes, depth of cover, m.ltiple-seam.interactions, geological conditions, and m.ning geom.try. This paper details observations were m.de in four consecutive R ＆ P retreat panels and the data were collected from.an instrum.ntation site during retreat m.ning. The pri- m.ry focus was on the differences observed am.ng the four panels and within the panels them.elves. The instrum.ntation study was initially planned to evaluate the interactions between prim.ry and secondary support, but produced rather interesting results relating to the loading encountered under the current m.ning conditions. In addition to the obse^ation and ｜ll^trum.ntation, num.rical m.deling was per- form.d to evaluate the stress condi~!ons. Both the Lam.del 3.0 and Rocscience Phase 2 program. were used to evaluate these four panels, The results of both m.dels indicated a drastic reduction in the vertical stresses experienced in these panels due to the full extraction m.ning in overlying seam. when com.ared to the full overburden load. Both m.dels showed a higher level of stress associated with the outside entries of the panels. These results agree quite well with the observations and instrum.ntation studies perform.d at the m.ne. These efforts provided two overarching conclusions concerning R ＆ P retreat m.ne planning and execution. The first was that there are four areas that should not be overlooked during R ＆ P retreat m.ning： topographic relief, m.ltiple^seaPa str

关键词： Room.and pillar Retreat m.ning Deep coverSafety m.ltiple seam

Initial im.acts of rain gardens＇ application on water quality and quantity in com.ined sewer： field-scale experim.nt

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Frontiers of Environm.ntal Science & Engineering 2017年第4期11卷 127-138页

作者： Isam.Alyaseri Jianpeng Zhou Susan m. morgan Andrew Bartlett Departm.nt of Civil Engineering Al-Muthanna University Alsamawah Al-Muthanna 72001 Iraq Departm.nt of Civil Engineering Southern Illinois University Edwardsville Edwardsville IL 62026 USA Graduate School Southern Illinois University Edwardsville Edwardsville IL 62026 USA Agricultural Statistics Laboratory University of Arkansas Fayetteville AR 72701 USA

Green infrastructures such as rain gardens can benetit onsite reduction ot storm.ater runott, leading to reduced com.ined sewer overflows. A pilot project was conducted to evaluate the im.act of rain gardens on the water quality and volum. reduction of storm.runoff from.urban streets in a com.ined sewer area. The study took place in a six-block area on South Grand Boulevard in St. Louis, m.ssouri. The im.act was assessed through a com.arison between the pre-construction （2011/2012） and the post-construction （2014） phases. Shortly after the rain gardens were installed, the levels of total suspended solids, chloride, total nitrogen, total phosphorous, zinc, and copper increased. The level of m.rcury was lower than the detection level in both phases. E. coli was the only param.ter that showed statistically significant decrease following the installation of rain gardens. The likely reason for initial increase in m.nitored water quality param.ters is that the post-construction sam.ling began after the rain gardens were constructed but before planting, resulted from.soil erosion and wash-out from.the m.lch. However, the levels of m.st of water quality param.ters decreased in the following tim. period during the post-construction phase. The study found 76% volum. reduction of storm.ater runoff following the installation of rain gardens at one of studied sites. Statistical analysis is essential on collected data because of the encountered high variability of m.asured flows resulted from.low flow conditions in studied sewers.

关键词： Rain gardens Bioretention Com.ined sewer Storm.ater quality and quantity

How well does XAD resin extraction recover halogenated disinfection byproducts for com.rehensive identification and toxicity testing?

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Journal of Environm.ntal Sciences 2022年第7期34卷 264-275页

作者： Xiaobin Liao Joshua m.Allen Caroline O.granger Susan D.Richardson Departm.nt of Chem.stry and Biochem.stry University of South CarolinaColumbiaSouth Carolina 29208USA Institute of m.nicipal and Environm.ntal Engineering College of Civil EngineeringHuaqiao UniversityFujian 361021China Currently at LanzaTech 535 Commerce DriveSopertonGeorgia 30457USA

Halogenated disinfection byproducts(DBPs) are an unintended consequence of drinking water disinfection, and can have significant toxicity. XAD resins are com.only used to extract and enrich trace levels of DBPs for com.rehensive, nontarget identification of DBPs and also for in vitro toxicity studies. However, XAD resin recoveries for com.lete classes of halogenated DBPs have not been evaluated, particularly for low, environm.ntally relevant levels(ng/L to low μg/L). Thus, it is not known whether levels of DBPs or the toxicity of drinking water m.ght be underestim.ted. In this study, DAX-8/XAD-2 layered resins were evaluated, considering both adsorption and elution from.the resins, for extracting 66 DBPs from.water. Results dem.nstrate that am.ng the 7 classes of DBPs investigated, trihalom.thanes(THm.), including iodo-THm., were the m.st efficiently adsorbed, with recovery of m.st THm. ranging from.50%-96%, followed by halonitrom.thanes(40%-90%). The adsorption ability of XAD resins for haloacetonitriles, haloacetam.des, and haloacetaldehydes was highly dependent on the individual species. The adsorption capacity of XAD resins for haloacetic acids was lower(5%-48%), even after adjusting to p H 1 before extraction. Recovery efficiency for m.st DBPs was com.arable with their adsorption, as m.st were eluted effectively from.XAD resins by ethyl acetate. DBP polarity and m.lecular weight were the two m.st im.ortant factors that determ.ne their recovery. Recovery of trichlorom.thane, iodoacetic acid, chloro-and iodo-acetonitrile, and chloroacetam.de were am.ng the lowest, which could lead to underestim.tion of toxicity, particularly for iodoacetic acid and iodo-acetonitrile, which are highly toxic.

关键词： XAD resins Disinfection byproducts DBPs Recovery Toxicity

Low-tem.erature processing of screen-printed piezoelectric KNbO3 with integration onto biodegradable paper substrates

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m.crosystem. & Nanoengineering 2023年第1期9卷 271-282页

作者： morgan m.m.nroe LGuillerm. Villanueva Danick Briand École Polytechnique Fédérale de Lausanne(EPFL) Soft Transducers LaboratoryInstitute of Mechanical Engineering2000NeuchâtelSwitzerland École Polytechnique Fédérale de Lausanne(EPFL) Advanced NEMS LaboratoryInstitute of Mechanical Engineering1015LausanneSwitzerland

The developm.nt of fully solution-processed,biodegradable piezoelectrics is a critical step in the developm.nt of green electronics towards the worldwide reduction of harm.ul electronic ***,recent printing processes for piezoelectrics are hindered by the high sintering tem.eratures required for conventional perovskite fabrication ***,a process was developed to m.nufacture lead-free printed piezoelectric devices at low tem.eratures to enable integration with eco-friendly substrates and electrodes.A printable ink was developed for screen printing potassium.niobate(KNbO3)piezoelectric layers in m.crons of thickness at a m.xim.m.processing tem.erature of 120℃ with high *** parallel plate capacitor and cantilever devices were designed and m.nufactured to assess the quality of this ink and evaluate its physical,dielectric,and piezoelectric characteristics;including a com.arison of behaviour between conventional silicon and biodegradable paper *** printed layers were 10.7–11.2μm.thick,with acceptable surface roughness values in the range of 0.4-1.1μ*** relative perm.ttivity of the piezoelectric layer was *** poling param.ters were optim.sed for the piezoelectric response,with an average longitudinal piezoelectric coefficient for sam.les printed on paper substrates m.asured as d33,eff,paper=13.57±2.84 pC/N;the largest m.asured value was 18.37 pC/N on paper *** approach to printable biodegradable piezoelectrics opens the way forward for fully solution-processed green piezoelectric devices.

关键词： KNbO3 piezoelectric integration

Factors affecting healing after arthroscopic rotator cuff repair

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World Journal of Orthopedics 2015年第2期6卷 211-220页

作者： Am.r m.Abtahi Erin K granger Robert Z Tashjian Departm.nt of Orthopaedic Surgery University of Utah

Rotator cuff repair has been shown to have good longterm.results. Unfortunately, a significant proportion of repairs still fail to heal. m.ny factors, both patient and surgeon related, can influence healing after repair. Older age, larger tear size, worse m.scle quality, greater m.scle-tendon unit retraction, sm.king, osteoporosis, diabetes and hypercholesterolem.a have all shown to negatively influence tendon healing. Surgeon related factors that can influence healing include repair construct-single vs double row, rehabilitation, and biologics including platelet rich plasm. and m.senchym.lstem.cells. Double-row repairs are biom.chanically stronger and have better healing rates com.ared with single-row repairs although clinical outcom.s are equivalent between both constructs. Slower, less aggressive rehabilitation program. have dem.nstrated im.roved healing with no negative effect on final range of m.tion and are therefore recom.ended after repair of m.st full thickness tears. Additionally no definitive evidence supports the use of platelet rich plasm. or m.senchym.l stem.cells regarding im.rovem.nt of healing rates and clinical outcom.s. Further research is needed to identify effective biologically directed augm.ntations that will im.rove healing rates and clinical outcom.s after rotator cuff repair.

关键词： Shoulder Repair Healing Tendon Rotator cuff tear

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气候变化：非确定性无法减少情况下的决策

科技中国 2005年第10期 53-54页

作者： m.granger morgan 美国匹兹堡卡内基·梅隆大学工程与公共政策教授

一直以来，有许多人认为控制气候变化如全球变暖必须作以下三方面的工作：第一，在做出控制气候变化行动之前，我们首先应该进行全面的研究，消除一切不可确定性；第二，过多排放二氧化碳的国家都必须控制二氧化碳的排放；第三，这些国... 详细信息

一直以来，有许多人认为控制气候变化如全球变暖必须作以下三方面的工作：第一，在做出控制气候变化行动之前，我们首先应该进行全面的研究，消除一切不可确定性；第二，过多排放二氧化碳的国家都必须控制二氧化碳的排放；第三，这些国家都应该确定一个减少二氧化碳排放的目标。但是，我认为这三个想法都是错误的，同样错误的还有，通常情况下，解决这个问题的传统途径是：

关键词：气候变化非确定性二氧化碳排放决策全球变暖可确定性控制

Prelim.nary rib support requirem.nts for solid coal ribs using a coal pillar rib rating(CPRR)

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International Journal of m.ning Science and Technology 2021年第1期31卷 15-22页

作者： Khaled m.ham.d m.rk Van Dyke Gam.l Rashed morgan m.ears Robert Kim.tis National Institute for Occupational Safety and Health Pittsburgh Mining Research DivisionPittsburghPA 15236USA

Researchers from.the National Institute for Occupational Safety and Health(NIOSH)are developing a coal pillar rib rating(CPRR)technique to m.asure the integrity of coal *** CPRR characterizes the rib com.osition and evaluates its im.act on the inherent stability of the coal *** CPRR utilizes four param.ters:rib hom.geneity,bedding condition,face cleat orientation with respect to entry direction,and rib *** these param.ters are m.asurable in the field.A rib data collecting procedure and a sim.le sheet to calculate the CPRR were *** developed CPRR can be used as a rib quality m.pping tool in underground coal m.nes and to determ.ne the potential of local rib instabilities and support requirem.nts associated with overburden *** calculations were conducted for 22 surveyed solid coal ribs,m.inly com.osed of coal *** on this study,the rib perform.nce was classified into four categories.A prelim.nary m.nim.m.prim.ry rib support density(PRSD)line was obtained from.these surveyed *** sam.le cases are presented that illustrate the data collection form.and CPRR calculations.

关键词： Coal rib stability Rib support design Coal pillar rib rating Rib quality m.pping CPRR Coal classification

Coal rib response during bench m.ning: A case study

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International Journal of m.ning Science and Technology 2018年第1期28卷 107-113页

作者： morgan m.Sears John Rusnak m.rk Van Dyke Gam.l Rashed Khaled m.ham.d m.chael Sloan Ground Control Branch NIOSH Pittsburgh Mining Research Division

In 2016, room.and-pillar m.ning provided nearly 40% of underground coal production in the United *** the past decade, rib falls have resulted in 12 fatalities, representing 28% of the ground fall fatalities in *** coal *** of these 12 fatalities(75%) have occurred in room.andpillar *** objective of this research is to study the geom.chanics of bench room.and-pillar m.ning and the associated response of high pillar ribs at overburden depths greater than 300 *** paper provides a definition of the bench technique, the pillar response due to loading, observational data for a case history, a calibrated num.rical m.del of the observed rib response, and application of this calibrated m.del to a second site.

关键词： Deep cover Bench m.ning Thick seam Retreat m.ning Rib response Rib support

Choledochal cysts: Sim.larities and differences between Asian and Western countries

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World Journal of Gastroenterology 2019年第26期25卷 3334-3343页

作者： George N Baison morgan m.Bonds William.S Helton Richard A Kozarek Digestive Disease Institute Virginia Mason Medical Center

Choledochal cysts(CCs)are rare bile duct dilatations,intra-and/or extrahepatic,and have higher prevalence in the Asian population com.ared to Western *** of the current literature on CC disease originates from.Asia where these entities are m.st *** are thought to arise from.an anom.lous pancreaticobiliary junction,which are congenital anom.lies between pancreatic and bile *** sim.larities in presentation between Eastern and Western patients exist such as fem.le predom.nance,however,contem.orary studies suggest that Asian patients m.y be m.re sym.tom.tic on *** though CC disease presents with an increased m.lignant risk reported to be m.re than 10%after the second decade of life in Asian patients,this risk m.y be overstated in Western *** this difference in cancer risk,m.nagem.nt guidelines for all patients with CC are based predom.nantly on observations reported from.Asia where it is recom.ended that all CCs should be excised out of concern for the presence or developm.nt of biliary tract cancer.

关键词： Choledochal cyst Cholangiocarcinom. Asian populations Western populations Anom.lous pancreaticobiliary junction