检索结果-南通市图书馆

Preventing roof fall fatalities during pillar recovery:A ground control success story

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International journal of Mining Science and Technology 2017年第1期27卷 107-113页

作者： Mark christopher Gauna Michael MSHA Pittsburgh Safety and Health Technology CenterPittsburghPA 15236USA

For decades, pillar recovery accounted for a quarter of all roof fall fatalities in underground coal *** showed that a miner on a pillar recovery section was at least three times more likely to be killed by a roof fall than other coal miners. Since 2007, however, there has been just one fatal roof fall on a pillar line. This paper describes the process that resulted in this historic achievement. It covers both the key research findings and the ways in which those insights, beginning in the early 2000 s, were implemented in mining practice. One key finding was that safe pillar recovery requires both global and local *** stability is addressed primarily through proper pillar design, and became a major focus after the2007 Crandall Canyon mine disaster. But the most significant improvements resulted from detailed studies that showed that local stability, defined as roof control in the immediate work area, could be achieved with three interventions:(1) leaving an engineered final stump, rather than extracting the entire pillar,(2) enhancing roof bolt support, particularly in intersections, and(3) increasing the use of mobile roof supports(MRS). A final component was an emphasis on better management of pillar recovery *** included a focus on worker positioning, as well as on the pillar and lift sequences, MRS operations,and hazard identification. As retreat mines have incorporated these elements into their roof control plans,it has become clear that pillar recovery is not ‘‘inherently unsafe." The paper concludes with a discussion of the challenges that remain, including the problems of rib falls and coal bursts.

关键词： Retreat mining Roof support Room-and-pillar Ground control

The effect of inlet conditions on the flow and heat transfer in multiple rotating cavity with axial throughflow

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

航空动力学报 2007年第5期22卷 683-693页

作者： christopher Long Peter Childs TFMRC Department of Engineering and Design University of Sussex Brighton BN1 9QT UK

This paper discusses experimental results from two different build configurations of a heated multiple rotating cavity test rig. Measurements of heat transfer from the discs and tangential velocities are presented. The test rig is a 70% full scale version of a high pressure compressor stack of an axial gas turbine engine. Of particular interest are the internal cylindrical cavities formed by adjacent discs and the interaction of these with a central axial throughflow of cooling air. Tests were carried out for a range of non-dimensional parameters representative of high pressure compressor internal air system flows (Reφup to 5×106 and ReΦup to 2×105).Two different builds have been tested. The most significant difference between these two build configurations is the size of the annular gap between the (non-rotating) drive shaft and the bores of the discs. The heat transfer data were obtained from thermocouple measurements of surface temperature and a conduction solution method. The velocity measurements were made using a two component, LDA system. The heat transfer results from the discs show differences between the two builds. This is attributed to the wider annular gap allowing more of the throughflow to penetrate into the cavity. There are also significant differences between the radial distributions of tangential velocity in the two builds of the test rig. For the narrow annular gap, there is an increase of non-dimensional tangential velocity Vφ/Ωr with radial location to solid body rotation Vφ/Ωr=*** the wider annular gap, the non-dimensional velocities show a decrease with radial location to solid body rotation.

关键词：轴向直流热转移旋转式孔进口接头

Current trends in urethral stricture management

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

Asian journal of Urology 2014年第1期1卷 46-54页

作者： christopher j.Hillary Nadir I.Osman christopher R.Chapple Department of Urology Royal Hallamshire HospitalSheffieldUK

The recent International Consultation on Urological Disease(ICUD)panel 2010 confirmed that a urethral stricture is defined as a narrowing of the urethra consequent upon ischaemic spongiofibrosis,as distinct from sphincter stenoses and a urethral disruption *** possible,an anastomotic urethroplasty should be performed because of the higher success rate as compared to augmentation *** is some debate currently regarding the critical stricture length at which an anastomotic procedure can be used,but clearly the extent of the spongiofibrosis and individual anatomical factors(the length of the penis and urethra)are important,the limitation for this being extension of dissection beyond the peno-scrotal junction and the subsequent production of *** recently,there has been interest in whether to excise and anastomose or to carry out a stricturotomy and reanastomosis using a Heineke-Miculicz *** urethroplasty has evolved towards the more extensive use of oral mucosa grafts as compared to penile skin flaps,as both flaps and grafts have similar efficacy and certainly the use of either dorsal or ventral positioning seems to provide comparable *** is important that the reconstructive surgeon is well versed in the full range of available repair techniques,as no single method is suitable for all cases and will enable the management of any unexpected anatomical findings discovered intra-operatively.

关键词： Urethral stricture Stricture Lichen sclerosus Pelvic fracture Urethral injury Bladder outflow obstruction Urethroplasty Buccal mucosa graft

Formal methods, statistical debugging and exploratory analysis in support of system development: Towards a verification and validation calculator tool

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International journal of Modeling, Simulation, and Scientific Computing 2016年第1期7卷 120-141页

作者： Saikou Y.Diallo Ross Gore christopher j.Lynch jose j.Padilla Virginia Modeling Analysis and Simulation Center Old Dominion University 1030 University Blvd.SuffolkVA 23435USA

In this paper,we propose an approach to formally verify and rigorously validate a simulation system against the specification of the real *** implement the approach in a verification and validation calculator tool that takes as input a set of statements that capture the requirements,internal conditions of the system and expected outputs of the real system and produces as output whether the simulation satisfies the requirements,faithfully represents the internal conditions of the system and produces the expected *** provide a use case to show how subject matter experts can apply the tool.

关键词： Verification and validation formal methods modeling and simulation

Granular titanite from the Roter Kamm crater in Namibia:Product of regional metamorphism,not meteorite impact

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2022年第3期13卷 156-163页

作者： Aaron j.Cavosie christopher j.Spencer Noreen Evans Kai Rankenburg Robert j.Thomas Paul H.Macey Space Science and Technology Centre and The Institute for Geoscience Research School of Earth and Planetary ScienceCurtin UniversityPerthWA 6102Australia Dept.of Geological Sciences and Geological Engineering Queen’s UniversityOntarioCanada john de Laeter Centre Curtin UniversityPerthWA 6102Australia Council for Geoscience BellvilleWestern CapeSouth Africa

Accessory minerals with so-called granular texture have risen in importance as geochronological tools for U-Pb dating of meteorite impact events. Grain-scale recrystallization, typically triggered by a combination of high-strain deformation and post-impact heating, can create a polycrystalline microstructure consisting of neoblasts that expel radiogenic Pb, which are thus ideal for isotopic dating. While granular domains in zircon and monazite from shocked rocks have been demonstrated to preserve impact ages,few U-Pb dating studies have been conducted on granular microstructures in titanite(CaTiSiO;). Here we report the occurrence of granular-textured titanite from ~2020 Ma granite basement rock exposed in the rim of the 4–5 Ma Roter Kamm impact structure in Namibia. Orientation mapping reveals two microstructurally distinct titanite populations: one consisting of strained/deformed grains, and the other consisting of grains that comprise aggregates of strain-free neoblasts. In situ U-Pb geochronology on 37 grains shows that most grains from both titanite populations yield indistinguishable U-Pb dates of ca.1025 Ma, consistent with the observed microstructures forming during the Mesoproterozoic Namaqua Orogeny. Only four grains preserved older age domains, recording ca. 1875 Ma Paleoproterozoic metamorphism. Two significant observations emerge:(1) none of the analyzed titanite grains yield the 2020 Ma igneous crystallization age previously established from zircon in the same sample, and(2) no age-resetting was detected that could be attributed to the 4 to 5 Ma Roter Kamm impact *** the similarity of the neoblastic microstructure to minerals from other sites with an established impact provenance, the granular texture and near-complete Pb-loss in titanite from Roter Kamm granite instead records a Paleo-to Mesoproterozoic polymetamorphic history, rather than Miocene age shockrelated processes. These results highlight the critical importance of grain-scale cont

关键词： Namibia Roter Kamm Titanite EBSD Geochronology

Effect of protective cultures on spoilage bacteria and the quality of vacuum-packaged lamb meat

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

Food Bioscience 2022年第6期50卷 1615-1624页

作者： Michelle M.Xu Mandeep Kaur christopher j.Pillidge Peter j.Torley Biosciences and Food Technology School of ScienceRMIT UniversityPO Box 71BundooraVictoria3083Australia

Protective cultures,as natural antimicrobials,have the ability to suppress the growth of spoilage bacteria and can potentially be used to extend the shelf-life of fresh meat and help reduce food *** there have been limited reports on the application of this approach in fresh red meat,the aim of this study was to evaluate the potential and practicality of this approach for red meat shelf-life extension based on the antimicrobial efficacy and quality impact of selected protective *** protective cultures(one containing Lactobacillus sakei and the other containing Staphylococcus carnosus and ***)were applied to chill-stored(4°C)vacuum-packaged lamb meat to determine their effects on spoilage bacteria as well as non-microbiological meat quality over a 20-day storage *** protective cultures dominated the microbiota throughout storage and effectively suppressed the growth of common meat spoilage bacteria,Brochothrix thermosphacta,Pseudomonas spp.,and *** color(measured in CIE L*a*b*color space)changed slightly in culture-treated samples in the later stage of storage,but the changes were not unacceptable based on previously reported thresholds for consumer *** mixed culture containing additional *** exhibited a slightly stronger inhibitory effect against the spoilage bacteria but also caused more changes in meat *** culture addition did not significantly affect meat pH,texture,or ***,these results demonstrated the potential of biopreservation using protective cultures for fresh red meat shelf-life extension.

关键词： Biopreservation Natural antimicrobial Lactobacillus sakei Staphylococcus carnosus Fresh meat Shelf-life

IgG and fibrinogen driven nanoparticle aggregation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2015年第8期8卷 2733-2743页

作者： Risto Cukalevski Silvia A. Ferreira christopher j. Dunning Tord Berggard Tommy Cedervall Department of Biochemistry and Structural Biology Centre for Molecular Protein Science Chemical Centre Lund University PO Box 124 SE-22100 Lund Sweden Centre for Biological Engineering University of Minho Campus Gualtar 4710-057 Braga Portugal Neuronal Survival Unit Department of Experimental Medical Science Wallenberg Neuroscience Center Lund University BMC B 11 22184 Lund Sweden Alligator Bioscience AB Lund Sweden

A thorough understanding of how proteins induce nanoparticle （NP） aggregation is crucial when designing in vitro and in vivo assays and interpreting experimental results. This knowledge is also crucial when developing nano-applications and formulation for drug delivery systems. In this study, we found that extraction of immunoglobulin G （IgG） from cow serum results in lower polystyrene NPs aggregation. Moreover, addition of isolated IgG or fibrinogen to fetal cow serum enhanced this aggregation, thus demonstrating that these factors are major drivers of NP aggregation in serum. Counter-intuitively, NP aggregation was inversely dependent on protein concentration; i.e., low protein concentrations induced large aggregates, whereas high protein concentrations induced small aggregates. Protein-induced NP aggregation and aggregate size were monitored by absorbance at 400 nm and dynamic light scattering, respectively. Here, we propose a mechanism behind the protein concentration dependent aggregation; this mechanism involves the effects of multiple protein interactions on the NP surface, surface area limitations, aggregation kinetics, and the influence of other serum proteins.

关键词： nanoparticles(NPs) protein coron aggregation immunoglobulin

Hypothesized summative anal physiology score correlates but poorly predicts incontinence severity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World journal of Gastroenterology 2017年第31期23卷 5732-5738页

作者： christopher j Young Assad Zahid Cherry E Koh jane M Young Department of Colorectal Surgery University of Sydney RPAH Medical Centre Discipline of Surgery University of Sydney Surgical Outcome Research Centre(SOu RCe) Royal Prince Alfred HospitalUniversity of Sydney School of Public health University of Sydney

To explore the relationship between such a construct and an existing continence score. METHODSA retrospective study of incontinent patients who underwent anal physiology (AP) was performed. AP results and Cleveland Clinic Continence Scores (CCCS) were extracted. An anal physiology score (APS) was developed using maximum resting pressures (MRP), anal canal length (ACL), internal and external sphincter defects and pudendal terminal motor latency. Univariate associations between each variable, APS and CCCS were assessed. Multiple regression analyses were performed. RESULTSOf 508 (419 women) patients, 311 had both APS and CCCS measured. Average MRP was 51 mmHg (SD 23.2 mmHg) for men and 39 mmHg (19.2 mmHg) for women. Functional ACL was 1.7 cm for men and 0.7 cm for women. Univariate analyses demonstrated significant associations between CCCS and MRP (P = 0.0002), ACL (P = 0.0006) and pudendal neuropathy (P < 0.0001). The association between APS and CCCS was significant (P < 0.0001) but accounted for only 9.2% of the variability in CCCS. Multiple regression showed that the variables most useful in predicting CCCS were external sphincter defect, pudendal neuropathy and previous pelvic surgery, but only improving the scores predictive ability to 12.5%. CONCLUSIONThis study shows that the ability of AP tests to predict continence scores improves when considered collectively, but that a constructed summation model before and after multiple regression is poor at predicting the variability in continence scores.

关键词： Incontinence Anal physiology Anal canal Anal ultrasound Manometry Electromyography

Impact of exome sequencing in inflammatory bowel disease

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World journal of Gastroenterology 2013年第40期19卷 6721-6729页

作者： christopher j Cardinale judith R Kelsen Robert N Baldassano Hakon Hakonarson Center for Applied Genomics Children’s Hospital of PhiladelphiaAbramson Research Center Suite 1216PhiladelphiaPA 19104United States Division of Gastroenterology Hepatologyand NutritionDepartment of PediatricsChildren’s Hospital of PhiladelphiaPerelman School of Medicine at the University of PennsylvaniaPhiladelphiaPA 19104United States

Approaches to understanding the genetic contribution to inflammatory bowel disease(IBD)have continuously evolved from family-and population-based epidemiology,to linkage analysis,and most recently,to genome-wide association studies(GWAS).The next stage in this evolution seems to be the sequencing of the exome,that is,the regions of the human genome which encode *** GWAS approach has been very fruitful in identifying at least 163 loci as being associated with IBD,and now,exome sequencing promises to take our genetic understanding to the next *** this review we will discuss the possible contributions that can be made by an exome sequencing approach both at the individual patient level to aid with disease diagnosis and future therapies,as well as in advancing knowledge of the pathogenesis of IBD.

关键词： Sequencing Exome Genetics Inflammatory bowel disease