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Science of empirical design in mining ground control

International Journal of Mining Science and Technology 2016年第3期26卷 461-470页

作者： Mark christopher MSHA Pittsburgh Safety & Health Technology Center

Many problems in rock engineering are limited by our imperfect knowledge of the material properties and failure mechanics of rock masses. Mining problems are somewhat unique, however, in that plenty of real world experience is generally available and can be turned into valuable experimental *** pillar that is developed, or stope that is mined, represents a full-scale test of a rock mechanics design. By harvesting these data, and then using the appropriate statistical techniques to interpret them,mining engineers have developed powerful design techniques that are widely used around the *** empirical methods are readily accepted because they are simple, transparent, practical, and firmly tethered to reality. The author has been intimately associated with empirical design for his entire career, but his previous publications have described the application of individual techniques to specific problems. The focus of this paper is the process used to develop a successful empirical method. A sixstage process is described: identification of the problem, and of the end users of the final product; development of a conceptual rock mechanics model, and identification of the key parameters in that model;identification of measures for each of the key parameters, and the development of new measures(such as rating scales) where necessary; data sources and data collection; statistical analysis; and packaging of the final product. Each of these stages has its own potential rewards and pitfalls, which will be illustrated by incidents from the author's own experience. The ultimate goal of this paper is to provide a new and deeper appreciation for empirical techniques, as well as some guidelines and opportunities for future developers.

关键词： Design Pillar Stope Empirical Statistics Modeling

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Current trends in urethral stricture management

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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

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With the wizard of the unit circle-An appreciation of ***

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Journal of Hydrodynamics 2019年第6期31卷 1085-1088页

作者： christopher Earls Brennen richard and Dorothy Hayman Professor of Mechanical Engineering EmeritusCalifornia Institute of TechnologyPasadenaCalifornia 91125

An account of my interactions with *** Yao-tsu Wu of the California Institute of Technology.

关键词： Caltech fluid mechanics cavitation

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Impact of exome sequencing in inflammatory bowel disease

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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

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Positron Emission Projection Imaging:A technique for concentration field measurements in opaque industrial systems

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Particuology 2024年第11期94卷 1-15页

作者： roberto Hart-Villamil Jack Sykes Andy Ingram christopher r.K.Windows-Yule Santosh Kumar Gupta School of Chemical Engineering University of BirminghamB152TTUK School of Physics and Astronomy University of BirminghamB152TTUK Hindustan Unilever r&D BengaluruKarnataka560066India

A novel Positron Emission Projection Imaging(PEPI)algorithm designed to compute the plane-projected spatial distribution of radiolabelled materials without the need for collimation is *** leveraging improved data efficiency,we have achieved a technique with enhanced spatial resolution and temporal resolution compared to previous PEPI *** of this algorithm was conducted using synthetic data generated from a digital twin of a PET scanner,demonstrating its accuracy for practical *** industrial advantage of this novel algorithm was applied in the imaging of laminar flow mixing within a ploughshare mixer,with the experimental results compared against those obtained from validated computational fluid dynamics(CFD)*** comparison highlights an important use case for PEPI as a robust validation tool for CFD simulations,crucial for enhancing industrial ***,which uses deeply penetrating gamma-photons,is now capable of imaging opaque fluids and solids in industrial *** directions for this work include further algorithmic refinements and expanding its application across various industrial systems,establishing PEPI as a robust tool for in-depth industrial process *** advancements presented here allow for optimized mixer design and enhanced process efficiency,extending the frontiers of tomographic imaging in industrial applications.

关键词： Positron emission projection imaging Positron emission particle tracking Computational fluid dynamics Mixing Ploughshare mixer

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Animal models of amyotrophic lateral sclerosis： a comparison of model validity

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Neural regeneration research 2018年第12期13卷 2050-2054页

作者： Jessica r.Morrice Cheryl Y.Gregory-Evans christopher A.Shaw Experimental Medicine Program University of British Columbia Vancouver Canada Department of Ophthalmology and Visual Sciences University of British Columbia Vancouver Canada Neuroscience Program University of British Columbia Vancouver Canada Department of Pathology. University of British Columbia Vancouver Canada

Animal models are necessary to investigate the pathogenic features underlying motor neuron degeneration and for therapeutic development in amyotrophic lateral sclerosis（ALS）. Measures of model validity allow for a critical interpretation of results from each model and caution from over-interpretation of experimental models. Face and construct validity refer to the similarity in phenotype and the proposed causal factor to the human disease, respectively. More recently developed models are restricted by limited phenotype characterization, yet new models hold promise for novel disease insights, thus highlighting their importance. In this article, we evaluate the features of face and construct validity of our new zebrafish model of environmentally-induced motor neuron degeneration and discuss this in the context of current environmental and genetic ALS models, including C9 orf72, mutant Cu/Zn superoxide dismutase 1 and TAr DNA-binding protein 43 mouse and zebrafish models. In this mini-review, we discuss the pros and cons to validity criteria in each model. Our zebrafish model of environmentally-induced motor neuron degeneration displays convincing features of face validity with many hallmarks of ALS-like features, and weakness in construct validity. However, the value of this model may lie in its potential to be more representative of the pathogenic features underlying sporadic ALS cases, where environmental factors may be more likely to be involved in disease etiology than single dominant gene mutations. It may be necessary to compare findings between different strains and species modeling specific genes or environmental factors to confirm findings from ALS animal models and tease out arbitrary strain-and overexpression-specific effects.

关键词： amyotrophic lateral sclerosis motor neuron degeneration face validity construct validity zebrafish models mouse models genetic models environmental models

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Development of minimally invasive techniques for management of medically-complicated obesity

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World Journal of Gastroenterology 2014年第37期20卷 13424-13445页

作者： Farzin rashti Ekta Gupta Suzan Ebrahimi Timothy r Shope Timothy r Koch christopher J Gostout Section of Gastroenterology and Hepatology MedStar-Washington Hospital Center and Georgetown University Schoolof Medicine Department of Surgery MedStar-Washington Hospital CenterCenter for Advanced Laparoscopic and Bariatric Surgery Division of Gastroenterology and Hepatology Mayo Medical School

The field of bariatric surgery has been rapidly growing and evolving over the past several decades. During the period that obesity has become a worldwide epidemic, new interventions have been developed to combat this complex disorder. The development of new laparoscopic and minimally invasive treatments for medically-complicated obesity has made it essential that gastrointestinal physicians obtain a thorough understanding of past developments and possible future directions in bariatrics. New laparoscopic advancements provide patients and practitioners with a variety of options that have an improved safety profile and better efficacy without open, invasive surgery. The mechanisms of weight loss after bariatric surgery are complex and may in part be related to altered release of regulatory peptide hormones from the gut. Endoscopic techniques designed to mimic the effects of bariatric surgery and endolumenal inter-ventions performed entirely through the gastrointestinal tract offer potential advantages. Several of these new techniques have demonstrated promising, preliminary results. We outline herein historical and current trends in the development of bariatric surgery and its transition to safer and more minimally invasive procedures designed to induce weight loss.

关键词： Obesity Bariatrics Bariatric surgery Weight loss Endoscopy

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Biological and cultural diversity in the context of botanic garden conservation strategies

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Plant Diversity 2017年第6期39卷 396-401页

作者： christopher P.Dunn Cornell Botanic Gardens 124 Comstock Knoll Drive Cornell University

Impacts of global climate change, habitat loss, and other environmental changes on the world's biota and peoples continue to increase, especially on islands and in high elevation areas. Just as floristic diversity is affected by environmental change, so too are cultural and linguistic diversity. Of the approximately 7000 extant languages in the world, fully 50% are considered to be at risk of extinction, which is considerably higher than most estimates of extinction risks to plants and animals. To maintain the integrity of plant life, it is not enough for botanic gardens to consider solely the effects of environmental change on plants within the context of major conservation strategies such as the Global Strategy for Plant Conservation and the Convention on Biological Diversity. rather, botanic gardens should actively engage in understanding and communicating the broader impacts of environmental change to biological and cultural diversity.

关键词： Biocultural diversity Botanic gardens Linguistic diversity Plant diversity

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Unanticipated multiple seam stresses from pillar systems behaving as pseudo gob–case histories

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International Journal of Mining Science and Technology 2017年第1期27卷 131-137页

作者： Gauna Michael Mark christopher Pittsburgh Safety and Health Technology Center Mine Safety and Health Administration(MSHA)PittsburghPA 15236USA

Underground coal mining in the U.S. is conducted in numerous regions where previous workings exist above and/or below an actively mined seam. Miners know that overlying or underlying fully extracted coal areas, also known as gob regions, can result in abutment stresses that affect the active mining. If there was no full extraction, and the past mining consists entirely of intact pillars, the stresses on the active seam are usually minimal. However, experience has shown that in some situations there has been sufficient yielding in overlying or underlying pillar systems to cause stress transfer to the adjoining larger pillars or barriers, which in turn, transfer significant stresses onto the workings of the active seam. In other words, the overlying or underlying pillar system behaves as a ‘‘pseudo gob." The presence of a pseudo gob is often unexpected, and the consequences can be severe. This paper presents several case histories, summarized briefly below, that illustrate pseudo gob phenomenon:(1) pillar rib degradation at a West Virginia mine at 335 m depth that contributed to a rib roll fatality,(2) pillar rib deterioration at a Western Kentucky mine at 175 m depth that required pillar size adjustment and installation of supplemental bolting,(3) roof deterioration at an eastern Kentucky mine at 400 m depth that stopped mine advance and required redirecting the section development,(4) coal burst on development at an eastern Kentucky mine at 520 m depth that had no nearby pillar recovery, and(5) coal burst on development at a West Virginia mine at the relatively shallow depth of 335 m that also had no nearby pillar recovery. The paper provides guidance so that when an operation encounters a potential pseudo gob stress interaction the hazard can be mitigated based on an understanding of the mechanism encountered.

关键词： Underground mining Coal Multiple seam Gob Ground control

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radical Addition of Perfluorinated Alkyl Iodides to Multi- Layered Graphene and Single-Walled Carbon Nanotubes

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Nano research 2010年第2期3卷 138-145页

作者： christopher E.Hamilton Jay r.Lomeda Zhengzong Sun James M.Tour Andrew r.Barron richard E.Smalley Institute for Nanoscale Science and Technology Department of Chemistry and Department of Mechanical Engineering and Materials ScienceRice UniversityHoustonTexas 77005USA

A simple one-pot reaction that serves to functionalize graphite nanosheets(graphene)and single-walled carbon nanotubes(SWNTs)with perfluorinated alkyl groups is *** radical addition of 1-iodo-1H,1H,2H,2H-perfluorododecane to ortho-dichlorobenzene suspensions of the carbon nanomaterial is initiated by thermal decomposition of benzoyl ***,UV photolysis of 1-iodo-perfluorodecane serves to functionalize the carbon ***-SWNTs,perfluorododecyl-graphene,and perfluorodecyl-graphene are characterized by infrared(Ir)and raman spectroscopy,X-ray photoelectron spectroscopy(XPS),thermogravimetric analysis(TGA),and atomic force microscopy(AFM).The products show enhanced dispersability in CHCl3 as compared to unfunctionalized starting *** advantage of this one-pot functionalization procedure lies in the use of pristine graphite as starting material thereby avoiding the use of harsh oxidizing conditions.

关键词： Nanotube single-walled carbon nanotube graphene radical addition

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