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Design concerns of room.and pillar retreat panels

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 encountered? 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.ning entries, four consecutive R & P retreat panels were evaluated. This evaluation was intended to reinforce 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 prim.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 observation and instrum.ntation, num.rical m.deling was perform.d to evaluate the stress conditions. Both the La m.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-seam.stress relief, stress concentrations near the gob edge,and g

关键词：面板支柱设计仪器仪表相互作用开采条件地形变化地质条件

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Im.act on Soil Organic C and Total Soil N from.Cool- and Warm.Season Legum.s Used in a Green m.nure-Forage Cropping System

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Agricultural Sciences 2024年第3期15卷 333-357页

作者： Clark B. Neely Francis m. Rouquette Jr. Cristine L.S. morgan Frank m. Hons William.L. Rooney Gerald R. Sm.th Departm.nt of Soil and Crop Science Washington State University Pullman WA USA Texas A&m.AgriLife Research Overton TX USA Chief Scientific Officer Soil Health Institute Morrisville NC USA Departm.nt of Soil and Crop Science Texas A&M University College Station TX USA

Annual forage legum.s are im.ortant com.onents of livestock production system. in East Texas and the southeastern US. Forage legum.s contribute nitrogen (N) to cropping system. through biological N fixation, and their seasonal biom.ss production can be m.naged to com.lem.nt forage grasses. Our research objectives were to evaluate both warm. and cool-season annual forage legum.s as green m.nure for biom.ss, N content, ability to enhance soil organic carbon (SOC) and soil N, and im.act on post season forage grass crops. Nine warm.season forage legum.s (WSL) were spring planted and incorporated as green m.nure in the fall. Forage rye (Secale cereale L.) was planted following the incorporation of WSL treatm.nts. Eight cool-season forage legum.s (CSL) were fall planted in previously fallow plots and incorporated as green m.nure in late spring. Sorghum.sudangrass (Sorghum.bicolor x Sorghum.bicolor var. sudanense) was planted over all treatm.nts in early sum.er after forage rye harvest and incorporation of CSL treatm.nts. Sorghum.sudangrass was harvested in June, August and Septem.er, and treatm.nts were evaluated for dry m.tter and N concentration. Soil cores were taken from.each plot, split into depths of 0 to 15, 15 to 30 and 30 to 60 cm. and soil C and N were m.asured using com.ustion analysis. Nylon m.sh bags containing plant sam.les were buried at 15 cm.and used to evaluate decom.osition rate of above ground legum. biom.ss, including change in C and N concentrations. m.ngbean (Vigna radiata L. [Wilczek]) had the highest shoot biom.ss yield (6.24 t Dm.ha-1) and contributed the m.st total N (167 kg∙ha-1) and total C (3043 kg∙ha-1) of the WSL tested. Decom.osition rate of WSL biom.ss was rapid in the first 10 weeks and very slow afterward. Winter pea (Pisum.sativum.L. spp. sativum., arrow leaf clover (Trifolium.vesiculosum.Savi.), and crim.on clover (Trifolium.incarnatum.L.) were the m.st productive CSL in this trial. Austrian winter pea produced 8.41 t Dm.ha-1 with a total

关键词： Annual Legum.s Soil N Soil Organic C Green m.nure Deer Browse Forage Cropping System.

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Legum. Green m.nure and Intercropping for High Biom.ss Sorghum.Production

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Agricultural Sciences 2024年第6期15卷 605-621页

作者： Clark B. Neely Francis m. Rouquette Jr. Cristine L. S. morgan Frank m. Hons William.L. Rooney Gerald R. Sm.th Departm.nt of Soil and Crop Science Washington State University Pullman WA USA Texas A&m.AgriLife Research Overton TX USA Soil Health Institute Morrisville NC USA Departm.nt of Soil and Crop Science Texas A&M University College Station TX USA

Before the advent of cheap, synthetic fertilizers, legum.s were com.only used as green m.nure crops for their ability to fix atm.spheric nitrogen (N). A three-year study at Overton, TX exam.ned legum. integration into high-biom.ss sorghum.(Sorghum.bicolor L.) production system. on a Lilbert loam. fine sand recently cultivated after a fertilized berm.dagrass [Cynodon dactylon (L.) Pers.] pasture. In this split-split plot design, ‘Dixie’ crim.on clover (Trifolium.incarnatum.L.) and ‘Iron and Clay’ cowpea (Vigna unguiculata L.) were integrated into a high-biom.ss sorghum.production system.to evaluate im.acts on N concentration, C concentration, and yield of high-biom.ss sorghum.and their im.acts on soil total N and soil organic carbon (SOC). m.in plots were split into crim.on clover green m.nure (CLGm. and winter fallow (FALL) followed by three sub-plots split into warm.season crop rotations: cowpea green m.nure (CPGm., cowpea-sorghum.intercrop (CPSR), and sorghum.m.nocrop (SORG). Three N fertilizer treatm.nts (0, 45, 90 kg N∙ha−1) were random.zed and applied as sub-sub plots. The CLGm.increased (P sorghum.biom.ss yield (16.5 t Dm.ha−1) 28% in year three but had no effect in the first two years. The CPSR treatm.nt reduced sorghum.yield up to 62% com.ared to SORG;whereas CPGm.increased sorghum.yield 56% and 18% the two years following cowpea incorporation. Rate of N fertilizer had no effect on sorghum.biom.ss yield. Decrease in SOC and soil N over tim. indicated m.neralization of organic N and m.y explain why no N fertilizer response was observed in sorghum.biom.ss yield. Cowpea showed strong potential as a green m.nure crop but proved to be too com.etitive for successful intercropping in high-biom.ss sorghum.production system..

关键词： High-Biom.ss Sorghum Legum.s Green m.nure Intercrop Cowpea Crim.on Clover Soil Organic Carbon Soil Nitrogen

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Cautionary Rem.rks When Testing Agreem.nt between Two Raters for Continuous Scale m.asurem.nts: A Tutorial in Clinical Epidem.ology with Im.lem.ntation Using R

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Open Journal of Epidem.ology 2024年第1期14卷 56-74页

作者： m.ham.d m. Shoukri Departm.nt of Epidem.ology and Biostatistics Schulich School of Medicine and Dentistry University of Western Ontario London Canada

Background: When continuous scale m.asurem.nts are available, agreem.nts between two m.asuring devices are assessed both graphically and analytically. In clinical investigations, Bland and Altm.n proposed plotting subject-wise differences between raters against subject-wise averages. In order to scientifically assess agreem.nt, Bartko recom.ended com.ining the graphical approach with the statistical analytic procedure suggested by Bradley and Blackwood. The advantage of using this approach is that it enables significance testing and sam.le size estim.tion. We noted that the direct use of the results of the regression is m.sleading and we provide a correction in this regard. m.thods: Graphical and linear m.dels are used to assess agreem.nts for continuous scale m.asurem.nts. We dem.nstrate that software linear regression results should not be readily used and we provided correct analytic procedures. The degrees of freedom.of the F-statistics are incorrectly reported, and we propose m.thods to overcom. this problem.by introducing the correct analytic form.of the F statistic. m.thods for sam.le size estim.tion using R-functions are also given. Results: We believe that the tutorial and the R-codes are useful tools for testing and estim.ting agreem.nt between two rating protocols for continuous scale m.asurem.nts. The interested reader m.y use the codes and apply them.to their available data when the issue of agreem.nt between two raters is the subject of interest.

关键词： Lim.ts of Agreem.nt Pitm.n and morgan Tests Test of Parallelism The Arcsine Variance Stabilizing Transform.tion Sam.le Size Estim.tion

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Geotechnical considerations for concurrent pillar recovery in close-distance m.ltiple seam.

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International Journal of m.ning Science and Technology 2018年第1期28卷 21-27页

作者： Peter Zhang Berk Tulu morgan sears Jack Trackem.s Ground Control Branch NIOSHPittsburgh Mining Research Division Departm.nt of m.ning Engineering West Virginia University

Room.and-pillar m.ning with pillar recovery has historically been associated with m.re than 25% of all ground fall fatalities in underground coal m.nes in the United States.The risk of ground falls during pillar recovery increases in m.ltiple-seam.m.ning conditions.The hazards associated with pillar recovery in m.ltiple-seam.m.ning include roof cutters, roof falls, rib rolls, coal outbursts, and floor heave.When pillar recovery is planned in m.ltiple seam., it is critical to properly design the m.ning sequence and panel layout to m.nim.ze potential seam.interaction.This paper addresses geotechnical considerations for concurrent pillar recovery in two coal seam. with 21 m.of interburden under about 305 m.of depth of cover.The study finds that, for interburden thickness of 21 m. the m.ltiple-seam.m.ning influence zone in the lower seam.is directly under the barrier pillar within about 30 m.from.the gob edge of the upper seam.The peak stress in the interburden transfers down at an angle of approxim.tely 20°away from.the gob, and the entries and crosscuts in the influence zone are subjected to elevated stress during developm.nt and retreat.The study also suggests that, for full pillar recovery in close-distance m.ltiple-seam.scenarios,it is optim.l to superim.ose the gobs in both seam., but it is not necessary to superim.ose the pillars.If the entries and/or crosscuts in the lower seam.are developed outside the gob line of the upper seam.additional roof and rib support needs to be considered to account for the elevated stress in the m.ltiple-seam.influence zone.

关键词： Pillar recovery Room.and-pillar Retreat m.ning m.ltiple seam m.ning sequence Pillar design

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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 States.Over the past decade, rib falls have resulted in 12 fatalities, representing 28% of the ground fall fatalities in U.S.underground coal m.nes.Nine of these 12 fatalities(75%) have occurred in room.andpillar m.nes.The 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 m.This 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

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青藏高原腹地发现最早细石叶技术遗址

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中国科学：地球科学 2024年第5期54卷 1588-1601页

作者：靳英帅张晓凌王社江葛俊逸何伟达娃谭韵瑶杨紫衣 Christopher morgan 高星中国科学院脊椎动物演化与人类起源重点实验室中国科学院古脊椎动物与古人类研究所北京100044 中国科学院大学北京100049 西藏自治区文物保护研究所拉萨850000 那曲市文化和旅游局那曲852000 University of Nevada Reno 87557USA

细石叶技术产品是青藏高原发现最丰富的史前人类文化遗物,代表了早期人类在高原的大规模迁徙.然而,经过系统发掘、具有可靠年代数据的细石叶技术遗址在青藏高原发现较少,高原腹地更为缺乏,这对理解细石叶技术人群在高原大规模迁徙扩散... 详细信息

细石叶技术产品是青藏高原发现最丰富的史前人类文化遗物,代表了早期人类在高原的大规模迁徙.然而,经过系统发掘、具有可靠年代数据的细石叶技术遗址在青藏高原发现较少,高原腹地更为缺乏,这对理解细石叶技术人群在高原大规模迁徙扩散的时间和过程带来了诸多障碍.本文研究报道了青藏高原腹地海拔4600m.新发现的细石叶技术遗址——尼阿底遗址第3地点.技术-类型学分析结果显示,尼阿底遗址第3地点细石叶的生产主要包括楔形石核和半锥形石核两种技术,与旧石器时代晚期中国华北地区的细石叶技术特征接近.光释光测年(OSL)和碳十四测年(^(14)C)的结果表明,尼阿底遗址第3地点的年代为11000~10000a BP.尼阿底遗址第3地点作为目前青藏高原腹地发现的最早的细石叶技术遗址,为了解拥有细石叶技术的狩猎采集者到达高原腹地的时间及其可能的扩散路线提供了重要信息.另外,通过对整个高原细石叶技术发展的分析,结合分子生物学的成果对比显示,细石叶技术人群迁移进入高原可能与人类对高原的长期占领以及现代藏族人的形成有密切联系.

关键词：青藏高原腹地尼阿底遗址第3地点细石叶技术早全新世高海拔适应

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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 waste.However,recent printing processes for piezoelectrics are hindered by the high sintering tem.eratures required for conventional perovskite fabrication techniques.Thus,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 reproducibility.Characteristic 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 substrates.The printed layers were 10.7–11.2μm.thick,with acceptable surface roughness values in the range of 0.4-1.1μm.The relative perm.ttivity of the piezoelectric layer was 29.3.The 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 substrates.This approach to printable biodegradable piezoelectrics opens the way forward for fully solution-processed green piezoelectric devices.

关键词： KNbO3 piezoelectric integration

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Benign course of residual inflam.ation at end of treatm.nt of liver transplant recipients after sofosbuvir based therapy

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World Journal of Hepatology 2022年第3期14卷 602-611页

作者： Bahaaeldeen Ism.il Karim.m.Benrajab Pablo Bejarano Phillip Ruiz Debbie sears Andreas Tzakis Xaralam.os Bobby Zervos Division of Digestive Diseases and Nutrition University of Kentucky College of MedicineLexingtonKY 40536United States Departm.nt of Pathology Cleveland Clinic FloridaWestonFL 33331United States Departm.nt of Pathology University of Miami Miller School of MedicineMiamiFL 33136United States Departm.nt of Liver Transplant Cleveland Clinic FloridaWestonFL 33331United States

BACKGROUND Persistent inflam.ation on histology after successful hepatitis C(HCV)treatm.nt has been reported.However,data regarding the long-term.im.act in liver transplant recipients is lim.ted,particularly after using direct-acting antiviral(DAA)therapies.AIm.To evaluate the im.act of successful treatm.nt with DAAs on histological changes and occult HCV and to describe the clinical course of residual inflam.ation in liver transplant recipients.m.THODS We conducted a case series of 13 chronic HCV infected liver transplant recipients successfully treated with DAAs between Decem.er 2013 and m.y 2014.All patients were treated for 24 wk and had non-detectable serum.HCV RNA by the tim. of biopsy.Only patients with at least one liver biopsy at or after treatm.nt were included.We exam.ned liver biopsies for evidence of residual inflam.ation and the presence of intrahepatic HCV RNA.RESULTS Persistent inflam.ation was seen in 12/13 patients on end of treatm.nt biopsy.Inflam.ation was still seen in the available five follow-up biopsies(range 38-48 wk after the end of treatm.nt).Intrahepatic HCV RNA was undetectable in all biopsies.All patients had preserved graft function for a m.an follow-up of 2.5 years,except one that developed chronic rejection.CONCLUSION After successful HCV treatm.nt with DAAs,liver transplant recipients m.y have persistent inflam.ation on biopsy without evidence of intracellular RNA.The clinical outcom. rem.ined favorable in m.st patients.Further studies with a larger num.er and longer follow-up are needed to establish the im.lication of this finding on long-term.graft function.

关键词： Im.unosuppression Liver transplantation Recurrent hepatitis C Sustained virologic response Interferon

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Artificial gut and the applications in poultry:A review

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Anim.l Nutrition 2022年第3期10卷 156-166页

作者： Nishchal K.Sharm. Shu-Biao Wu Natalie K.morgan Tam.yn m.Crowley School of Environm.ntal and Rural Science University of New EnglandArmidaleNSW2351Australia Poultry Hub Australia University of New EnglandArmidaleNSW2351Australia Im.ACT School of MedicineDeakin UniversityGeelongVictoria3217Australia

Artificial gut m.dels including both the gastric and intestinal phases have been used in poultry research for decades to predict the digestibility of nutrients,the efficacy of feed enzym.s and additives,and caecal ferm.ntation.However,the m.dels used in the past are static and cannot be used to predict interactions between the feed,gut environm.nt and m.crobiom..It is im.erative that a standard artificial gut m.del for poultry is established,to enable these interactions to be exam.ned without continual reliance on anim.ls.To ensure the validity of an artificial m.del,it should be validated with in vivo studies.This review describes current practices in the use of artificial guts in research,their im.ortance in poultry nutrition studies and highlights an opportunity to develop a dynam.c gut m.del for poultry to reduce the num.er of in vivo experim.nts.

关键词： Artificial gut Gastrointestinal tract In vitro experim.nt Poultry Sim.lated gut

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