检索结果-南通市图书馆

A case study of the stability of a non-typical bleeder entry system at a *** mine

International Journal of Mining Science and Technology 2020年第1期30卷 25-31页

作者： T.M.Klemetti M.A.Van dyke I.B.Tulu d.tuncay NIOSH Pittsburgh Mining Research division Pittsburgh 15236USA department of Mining Engineering West Virginia UniversityMorgantown 26505USA

Longwall abutment loads are influenced by several factors,including depth of cover,pillar sizes,panel dimensions,geological setting,mining height,proximity to gob,intersection type,and size of the *** does proximity to the gob affect pillar loading and entry condition?does the gob influence depend on whether the abutment load is a forward,side,or rear loading?do non-typical bleeder entry systems follow the traditional front and side abutment loading and extent concepts?If not,will an improved understanding of the combined abutment extent warrant a change in pillar design or standing support in bleeder entries?This paper details observations made in the non-typical bleeder entries of a moderate depth longwall panel—specifically,data collected from borehole pressure cells and roof extensometers,observations of the conditions of the entries,and numerical modeling of the bleeder entries during longwall *** primary focus was on the extent and magnitude of the abutment loading experienced due to the extraction of the longwall *** to the layout of the longwall panels and bleeder entries,the borehole pressure cells(BPCs)and roof extensometers did not show much change due to the advancing of the first ***,they did show a noticeable increase due to the second longwall advancement,with a maximum of about 4 MPa of pressure increase and 5mmof roof *** observations of the conditions showed little to no change from before the first longwall panel extraction began to when the second longwall panel had been advanced more than 915 *** pillar spalling was observed on the corners of the pillars closest to the longwall gob as well as an increase in water in the *** addition to the observations and instrumentation,numerical modeling was performed to validate modeling procedures against the monitoring results and evaluate the bleeder *** Consulting Group’s FLAC3d numerical modeling software was used to evaluate the bl

关键词： Abutment loading Longwall Instrumentation Bore hole pressure cells Pillar loading Yield pillar Bleeder pillar

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigating different methods used for approximating pillar loads in longwall coal mines

引用

International Journal of Mining Science and Technology 2021年第1期31卷 23-32页

作者： deniz tuncay a Ihsan Berk Tulu a Ted Klemetti department of Mining Engineering West Virginia UniversityMorgantown 26501USA NIOSH Pittsburgh Mining Research division Pittsburgh 15236USA

Accurately estimating load distributions and ground responses around underground openings play a significant role in the safety of the operations in underground *** designing pillars and other support measures relies highly on the accurate assessment of the loads that will be carried by them,as well as the load-bearing capacities of the *** are various methods that can be used to approximate mining-induced loads in stratified rock masses to be used in pillar *** empirical methods are based on equations derived from large databases of various case *** are implemented in government approved design tools and are widely *** are also analytical and numerical techniques used for more detailed analysis of the induced *** this study,two different longwall mines with different panel width-to-depth ratios are analyzed using different *** empirical method used in the analysis is the square-decay stress function that uses the abutment angle concept,implemented in pillar design software developed by the National Institute for Occupational Safety and Health(NIOSH).The first numerical method used in the analysis is a displacement-discontinuity(dd)variation of the boundary element method,LaModel,which utilizes the laminated overburden *** second numerical method used in the analysis is Fast Lagrangian Analysis of Continua(FLAC)with the numerical modeling approach recently developed at West Virginia University which is based on the approach developed by *** model includes the 2d slice of a cross-section along the width of the panel with the chain pillar system that also includes the different stratigraphic layers of the *** three methods gave similar results for the shallow mine,both in terms of load percentages and distribution where the variation was more obvious for the deep cover *** FLAC3d model was observed to better capture the stress changes observed during the field measurements for both

关键词： Abutment loads Numerical modeling LaModel FLAC3d Longwall coal mines

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Anti-inflammatory efficiency of levobupivacaine in an experimental colitis model

引用

World Journal of Gastroenterology 2010年第20期16卷 2537-2541页

作者： Ugur duman Aysun Yilmazlar Ersin Ozturk Sibel Aker Emre Sarandol tuncay Yilmazlar department of General Surgery Uludag University School of Medicine16069 BursaTurkey department of Anesthesiology and Reanimation Uludag University School of Medicine16069 BursaTurkey department of Pathology Uludag University School of Medicine16069 BursaTurkey department of Biochemistry Uludag University School of Medicine16069 BursaTurkey

AIM:To investigate the efficiency of levobupivacaine in treating experimentally induced colitis in ***:Colitis was induced by trinitrobenzene sulfonic acid and ethanol in 30 rats under general anesthesia,and 10 rats were used as a sham *** to induction of colitis,rats were divided into three groups;budesonide group received 0.1 mg/kg budesonide,levobupivacaine group received 10 mg/kg levobupivacaine and saline group received 1 mL saline solution via rectal route for 7 *** the sham group,only routine rectal catheterization was performed without use of any *** the end of 7 d,laparotomy and total colectomy were performed for histopathological ex-amination in all rats and blood samples were drawn for measurement of tumor necrosis factor(TNF)-αand interleukin(IL)-6 following cardiac *** and microscopic evaluations of the specimens were performed by a pathologist blinded to group assignment of the ***:Weight loss(P=0.016)and macroscopic examination scores(P=0.001)were significantly higher in saline group than *** scoring was comparable between all colitis groups(P=0.350).There was no significant difference in TNF-αlevels and IL-6 levels(P=0.150).CONCLUSION:The significant improvement in macroscopic scores suggests that levobupivacaine may have topical anti-inflammatory effects in an experimental colitis model;however,this finding was not supported by microscopic findings.

关键词： Trinitrobenzene sulfonic acid Colitis Levobupivacaine Budesonide

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Late corneal ectasia after penetrating and deep anterior lamellar keratoplasty for keratoconus

引用

International Journal of Ophthalmology(English edition) 2024年第10期17卷 1828-1836页

作者： Bora Yüksel Arife Esra Kocakaya tuncay Küsbeci Fatih Gümüş department of Ophthalmology University of Health SciencesIzmir Bozyaka Education and Research HospitalIzmir 35110Türkiye

AIM:To investigate tomographic features of late corneal ectasia after keratoplasty for keratoconus and compare penetrating keratoplasty(PK)and deep anterior lamellar keratoplasty(dALK)in terms of incidence,time of onset and risk factors of corneal ***:Sixty eyes with PK and 30 eyes with dALK operated between 1999 and 2021 were *** Pentacam scans were evaluated together with vision and previous *** outcome measures were vision,K values,apparent thinning on graft-host cornea and the difference between opposing quadrants in the thinnest point *** segment optic coherence tomography was performed for further ***:Mean follow-up was 127.2mo(24–282mo)in PK,and 64.3mo(24–144mo)in dALK.K max was higher in dALK(60.6 vs 56.7 d,P=0.012).Inferior recipient was thinner(595.9μm)in PK than dALK(662.2μm,P=0.021),due to longer *** corneal ectasia rate was 20.0% within *** rate was the same(6.7%)in dALK 2/30 and in PK 4/60 in 10y and 13.3%in 12y(4/30 and 8/60,respectively).It increased to 23.3%(14/60)in PK over *** ectasia was not seen before 7y in PK,it could be seen in dALK starting from the 5^(th) *** intervals between keratoplasty and ectasia were 144.5mo in PK and 99mo in *** recipient was significantly thinner in 18 eyes with ectasia(502.7μm)compared to 76 non-ectasia(649.1μm,P=0.000).Inferior graft was thinner(561.0 vs 620.4μm,P=0.006),K max(63.3 vs 56.5 d,P=0.000),and anterior elevation was higher in ectasia(89.1 vs 48.6μm,P=0.002).Accelerated crosslinking was performed on 5 ***:Inferior-superior recipient and inferior graft thinning on tomography,with high K max and anterior elevation emerge as the most reliable criteria for the diagnosis of late *** incidence of corneal ectasia increases with the time.

关键词： keratoconus penetrating keratoplasty deep anterior lamellar keratoplasty corneal ectasia

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Comparison of visual and topographic outcomes of deep-anterior lamellar keratoplasty and penetrating keratoplasty in keratoconus

引用

International Journal of Ophthalmology(English edition) 2017年第3期10卷 385-390页

作者： Bora Yüksel Baran Kandemir Umut duygu Uzunel Ozan Celik Sezgin Ceylan tuncay Küsbeci department of Ophthalmology Izmir Bozyaka Training and Research Hospital Izmir 35110 Turkey department of Ophthalmology Kartal Training and Research Hospital Istanbul 34660 Turkey

AIM：To compare visual,surgical and topographic outcomes of deep anterior lamellar keratoplasty（dALK）and penetrating keratoplasty（PK）for keratoconus（KC）.METHOdS：In this multicenter,prospective,randomized clinical trial 76 eyes of 71 KC patients operated between January 2011 and July 2014 in 2 tertiary referral hospitals were included. Consecutive patients were alternately selected to receive one of the two surgical methods. Thirty eight eyes underwent dALK with the big-bubble technique and 38 eyes underwent ***：Mean best spectacle corrected visual acuity（BSCVA）at the first postoperative week（P=0.012）and the first postoperative month（P〈0.001）was statistically significantly higher in dALK group. The mean BSCVA at12 mo was not significantly different for dALK（0.30±1.99 log MAR）versus PK（0.40±0.33 log MAR）（P=0.104）. The76.3% of the eyes had a BSCVA over 0.5 in dALK and 47.4%in PK group（P=0.009）. The 7.9% of the eyes had a BSCVA of 1.0 in dALK and 5.3% in PK group（P=0.644）. Mean spherical equivalent was-2.94 d in dALK and-3.09 d in PK *** topographic astigmatism was 4.62 d and 4.18 d respectively. Regular topographic patterns were observed in 31（81.6%）of dALK and 29（76.3%）of PK（P=0.574）. The most frequent topographic pattern was oblate asymmetric bow tie,seen in 39.5% in dALK and 23.7% in PK. CONCLUSION：Big bubble dALK provides an earlier visual improvement compare to PK. However,visual and topographic outcomes are similar to those in PK at 1y. Postoperative complications including rejection and intraocular pressure elevation are more frequent in PK. dALK is a safer alternative to PK for KC. However,intraoperativeperforation of the descemet＇s membrane is a significant complication.

关键词： deep anterior lamellar keratoplasty keratoconus penetrating keratoplasty

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High-resolution seismicity imaging and early aftershock migration of the 2023 Kahramanmara?(SE Türkiye)M_W7.9&7.8 earthquake doublet

引用

Earthquake Science 2023年第6期36卷 417-432页

作者： Hongyang ding Yijian Zhou Zengxi Ge tuncay Taymaz Abhijit Ghosh Haoyu Xu Tahir Serkan Irmak Xiaodong Song Institute of Theoretical and Applied Geophysics Peking UniversityBeijing 100871China department of Earth and Planetary Sciences University of CaliforniaRiverside CA 92521USA Hebei Hongshan National Observatory on Thick Sediments and Seismic Hazards Hebei 054000China department of Geophysical Engineering The Faculty of Minesİstanbul Technical UniversityMaslak 34467SarıyerİstanbulTürkiye department of Geophysical Engineering Kocaeli UniversityUmuttepe 41380KocaeliTürkiye

We build a high-resolution early aftershock catalog for the 2023 SE Türkiye seismic sequence with PALM,a seamless workflow that sequentially performs phase picking,association,location,and matched filter for continuous *** catalog contains 29,519 well-located events in the two mainshocks rupture region during 2023-02-01–2023-02-28,which significantly improves the detection completeness and relocation precision compared to the public routine *** the new PALM catalog,we analyze the structure of the seismogenic fault *** find that the Eastern Anatolian Fault(EAF)that generated the first M_(W)7.9 mainshock is overall near-vertical,whereas complexities are revealed in a small-scale,such as subparallel subfaults,unmapped branches,and *** seismicity on EAF is shallow(d concentrated in depth distribution,indicating a clear lock-creep *** contrast,the SürgüFault(SF)that is responsible for the second M_(W)7.8 mainshock is shovel-shaped for the nucleation segment and has overall low dip angles(~40°–80°).Aftershocks on the SF distribute in a broad range of depth,extending down to~35 *** also analyze the temporal behavior of seismicity,discovering no immediate foreshocks within~5 days preceding the first mainshock,and no seismic activity on the SF before the second mainshock.

关键词： 2023 Türkiye Earthquake doublet aftershock catalog PALM fault imaging aftershock migration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Birth,Survival and death of Languages by Monte Carlo Simulation

引用

Communications in Computational Physics 2008年第2期3卷 271-294页

作者： C.Schulze d.Stauffer S.Wichmann Institute for Theoretical Physics Cologne UniversityD-50923 KolnEuroland department of Linguistics Max Planck Institute for Evolutionary AnthropologyDeutscher Platz 6D-04103 LeipzigGermany.

Simulations mostly by physicists of the competition between adult languagessince 2003 are reviewed. The Viviane and Schulze models give good and reasonableagreement, respectively, with the empirical histogram of language sizes. Alsothe numbers of different languages within one language family is modeled reasonablyin an intermediate range. Bilingualism is now incorporated into the Schulze *** the rate at which the majority shifts from one language to another is found tobe nearly independent of the population size, or to depend strongly on it, accordingto details of the Schulze model. Other simulations, like Nettle-Culicover-Nowak, arereviewed more briefly.

关键词： Language competition Schulze model Viviane model agent-based modeling.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：