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Assessing Leak Paths in the Cement Sheath of a Cased Borehole by Analysis of Monopole Wavefield Modes

Communications in Computational Physics 2020年第6期28卷 424-441页

作者： Hua Wang michael Fehler Aiḿe Fournier University of electronic Science and Technology of China ChengduSichuan611731P.R.China earth Resources Laboratory Massachusetts Institute of TechnologyCambridgeMA02139USA

evaluation of possible leakage pathways of CO_(2) injected into geological formations for storage is essential for successful Carbon Capture and Storage(CCS).A channel in the borehole cement,which secures the borehole casing to the formation,may allow CO_(2) to *** assessment and remediation decisions about the pres-ence of such channels depend on channel parameters:radial position r from the center of the borehole;channel thickness d;azimuthal positionφof the channel;and az-imuthal extentθof the *** state-of-the-art cement-bond logging technology,which uses only the first arrival at a centralized borehole receiver,can diagnose limited details about CO_(2) leak *** accurately characterize the possible leak paths in the cement,we use a 3-dimensional finite-difference method to investigate the use of the abundant data collected by a modernized monopole sonic tool that contains an array of azimuthally distributed *** also investigate how to improve the tool design to acquire even more useful *** cases where borehole fluid is either water or supercritical CO_(2),we investigate various receiver geometries,multi-modal analyses of multi-frequency data to discover the type of logging tool that provides the best information for CCS *** find that an appropriate choice of wave modes,source frequencies,source polarities,and receiver locations and off-sets provides sensitivity to d,φ,θ.The amplitude of the first arrival from a monopole source is sensitive toθ.Amplitudes at receivers at different azimuths are sensitive toφ.The slow Stoneley mode(ST2)velocity is sensitive to d,but ST2 is not easy to pick whenθand d are *** improvement is necessary to provide comprehensive information about possible flow channels in casing cement.

关键词： Greenhouse effect CO_(2)leak channel cement bond evaluation borehole acoustic logging casing wave Stoneley waves

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Calcium signaling in cholangiocytes

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World Journal of Gastroenterology 2006年第22期12卷 3466-3470页

作者： Noritaka Minagawa Barbara e ehrlich michael H Nathanson Departments of Medicine and Pharmacology Yale University School of Medicine New Haven CTUnited States Section of Digestive Diseases Yale University School of Medicine 1 Gilbert StreetRoom TAC S241DNew HavenCT 06519United States

Cytosolic Ca^2＋ is an important second messenger in virtually every type of cell. Moreover, Ca^2＋ generally regulates multiple activities within individual cells. This article reviews the cellular machinery that is responsible for Ca^2＋ signaling in cholangiocytes. In addition, two Ca^2＋-mediated events in cholangiocytes are discussed： bicarbonate secretion and apoptosis. Finally, emerging evidence is reviewed that Ca^2＋ signaling is involved in the pathogenesis of diseases affecting the biliary tree and that Ca^2＋ signaling pathways can be manipulated to therapeutic advantage in the treatment of cholestatic disorders.

关键词： Ca^2+ Cholangiocyte Inositol trisphosphate Bile secretion Cholestasis Apoptosis

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Female mate choice and the potential for ornament evolution in túngara frogs Physalaemus pustulosus

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Current Zoology 2010年第3期56卷 343-357页

作者： michael J.RYAN Ximena e.BeRNAL A.Stanley RAND Section of Integrative Biology C0930 University of Texas Smithsonian Tropical Research Institution Department of Biological Science Texas Tech University Srnithsonian Tropical Research Institution

The potential for ornament evolution in response to sexual selection rests on the interaction between the permissive- ness or selectivity of female preferences and the constraints on male development of signaling related traits. We investigate the former by determining how latent female preferences either exaggerate the magnitude of current traits （i.e. elaborations） or favor novel traits （i.e. innovations）. In tt^ngara frogs, females prefer complex mating calls （whine-chucks） to simple calls （whine only）. The whine is critical for mate recognition while the chuck further enhances the attractiveness of the call. Here we use a combina- tion of synthetic and natural stimuli to examine latent female preferences. Our results show that a diversity of stimuli, including conspecific and heterospecific calls as well as predator-produced and human-made sounds, increase the attractiveness of a call when added to a whine. These stimuli do not make simple calls more attractive than a whine-chuck, however. In rare cases we found stimuli that added to the whine decrease the attractiveness of the call. Overall, females show strong preferences for both elaborations and innovations of the chuck. We argue that the emancipation of these acoustic adornments from mate recognition allows such female permissiveness, and that male constraints on signal evolution are probably more important in explaining why males evolved their specific adornment. experimentally probing latent female preferences for stimuli out of the species＇ range is a useful means to gain insights about the potential of female choice to influence signal evolution and thus the astounding diversity in male sexually-selected traits [Current Zoology 56 （3）： 343-357, 2010].

关键词： Mate choice Ornament evolution Tfingara frogs Physalaemus pustulosus

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Inhibition of central axon regeneration: perspective from chondroitin sulfate proteoglycans in lamprey spinal cord injury

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Neural Regeneration Research 2022年第9期17卷 1955-1956页

作者： Jianli Hu Li-Qing Jin michael e.Selzer Shriners Hospitals Pediatric Research Center(Center for Neural Repair and Rehabilitation) Lewis Katz School of Medicine at Temple UniversityPhiladelphiaPAUSA Department of Neurology Lewis Katz School of Medicine at Temple UniversityPhiladelphiaPAUSA

Background:Failure of axon regeneration after spinal cord injury(SCI)underlies the paralysis that so profoundly affects patients’quality of *** factors are involved in the regeneration *** sulfate proteoglycans(CSPGs),normal constituents of the perineuronal nets in central nervous system(CNS),are secreted at the injury site and initially were thought to act as a purely physical *** the past decade,the receptor-like protein tyrosine phosphatases,protein tyrosine phosphatase sigma(PTPσ),and leukocyte common antigen-related phosphatase(LAR),have been identified as transmembrane receptors for *** two receptors for myelin-associated growth inhibitors,Nogo receptors 1 and 3(NgR1 and NgR3)also have been found to bind with CSPGs(Sharma et al.,2012).These findings suggest that CSPGs inhibit regeneration by interacting with these receptors,initiating downstream inhibitory signaling(Figure 1).

关键词： paralysis injury leukocyte

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Ultrasound diagnosis of diverticulitis

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World Journal of emergency Medicine 2016年第1期7卷 74-76页

作者： michael e. Abboud Sarah e. Frasure michael B. Stone emergency Department Harvard University 45 Francis St Neville House - 236A Boston Massachusetts 02115 USA

Diverticular disease accounts for approximately 312 000 hospital admissions in the United States annually, and costs nearly 2.6 billion dollars. Approximately 20% of Americans with diverticular disease will experience at least one episode of acute diverticulitis, necessitating a visit to their physician＇s office or the emergency department （eD） for *** As the risk of developing diverticulitis rises with age （nearly 50% of people aged over 60 years have colonic diverticula）, the incidence is rising as the elderly population grows.

关键词： will oral

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Geography education for Sustainable Development

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Geography and Sustainability 2020年第1期1卷 88-92页

作者： michael e.Meadows Department of environmental&Geographical Science University of Cape TownRondebosch 7701South Africa School of Geographical Sciences East China Normal UniversityShanghai 200241China College of Geography and environmental Sciences Zhejiang Normal UniversityJinhua 321004China

Increased pressure on the earth’s resources has led to what is increasingly referred to as the climate *** a whole range of environmental parameters have been transformed through such pressures,the effect of human activities on the climate is symbolic of the nature of the human footprint upon our planet and makes the lack of any coherent political leadership in most countries even more *** discipline of Geography has a distinct advantage in developing a more holistic understanding of global environmental challenges in that it reaches across all the sciences(including social sciences and humanities).Geographical education therefore represents an important vehicle for citizens of all ages to help them understand the complexity of the sustainability goal and what can(and should)be done to achieve a more sustainable *** this essay,I reflect on three approaches that are available to individuals and communities towards taking the steps to *** philosophy embodied by the International Year of Global Understanding(IYGU)is suggested as a particularly valuable tool for geography *** activities of the International Geographical Union(IGU)offer important opportunities for geographers to learn from each other and promote best practice in geographical ***‘the science for sustainability’,Geography has an increasingly important role to play in developing the knowledge and the skills to equip future generations with the tools to adapt to and mitigate potentially catastrophic global environmental change.

关键词： Geographical education SDGs Anthropocene Global environmental change IYGU International Charter on Geographical education

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east African topography and volcanism explained by a single,migrating plume

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Geoscience Frontiers 2020年第5期11卷 1669-1680页

作者： Rakib Hassan Simon e.Williams michael Gurnis Dietmar Muller School of Geosciences Room 412Madsen Building F09 Eastern AvenueThe University of SydneyNSW2006Australia Seismological Laboratory California Institute of TechnologyPasadenaCA91125USA Now at Geoscience Australia GPO Box 378CanberraACT2601Australia State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi’an 710069China

Anomalous topographic swells and Cenozoic volcanism in east Africa have been associated with mantle *** models involving one or more fixed plumes beneath the northeastward migrating African plate have been suggested to explain the space-time distribution of magmatism in east *** devise paleogeographically constrained global models of mantle convection and,based on the evolution of flow in the deepest lower mantle,show that the Afar plume migrated southward throughout its *** models suggest that the mobile Afar plume provides a dynamically consistent explanation for the spatial extent of the southward propagation of the east African rift system(eARS),which is difficult to explain by the northeastward migration of Africa over one or more fixed plumes alone,over the last≈45 *** further show that the age-progression of volcanism associated with the southward propagation of eARS is consistent with the apparent surface hotspot motion that results from southward motion of the modelled Afar plume beneath the northeastward migrating African *** models suggest that the Afar plume became weaker as it migrated southwards,consistent with trends observed in the geochemical record.

关键词： Numerical mantle flow models Deep mantle flow LLSVP morphology Plume dynamics Plume motion Dynamic topography

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exploring and integrating cellulolytic systems of insects to advance biofuel technology

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Insect Science 2010年第3期17卷 163-165页

作者： Jian-Zhong Sun michael e. Scharf Biofuels Institute School of the Environment Jiangsu University Zhenjiang 212013Jiangsu China entomology and Nematology Department PO Box 110620 Bldg 970 Natural Area Dr. University of FloridaGainesville FL 32611-0620 USA

In line with the requirements for sustainable economies and clean environments, cellulose-based biofuels have recently received tremendous attention both in industry and academic communities worldwide. Alternative and renewable fuels derived from lignocellulosic biomass offer the potential to reduce our dependence on fossil fuels and mitigate global climate change.

关键词： exploring integrating cellulolytic systems advance biofuel

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Compressibility of a natural kyanite to 17.5 GPa

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Progress in Natural Science:Materials International 2009年第10期19卷 1281-1286页

作者： Sean R. Shieh michael e. Fleet Department of earth Sciences University of Western Ontario

The compressional behaviour of a natural kyanite,(Al1.99Fe0.01)SiO5,has been investigated to about 17.5 GPa at 300 K using a diamond-anvil cell and synchrotron X-ray *** pressure-volume data fitted to the third-order Birch-Murnaghan equation of state(eoS) yield an isothermal bulk modulus(K0T) of 192 ± 6 GPa and pressure derivative(K00T) of 6 ± *** K00T is fixed as 4,the derived K0T is 201 ± 2 *** values are in excellent agreement with most experimental determinations in the ***,it can be concluded that the compressibility of kyanite under high pressures has been accurately constrained.

关键词： Compressibility High-pressure Isothermal bulk modulus Kyanite Synchrotron X-ray diffraction

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Design of a water curtain to reduce accumulations of float coal dust in longwall returns

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International Journal of Mining Science and Technology 2020年第4期30卷 443-447页

作者： Clara e.Seaman michael R.Shahan Timothy W.Beck Steven e.Mischler National Institute for Occupational Safety and Health Pittsburgh Mining Research DivisionPittsburghPA 15236USA

Accumulation of float coal dust(FCD)in underground mines is an explosion hazard that affects all underground coal mine *** this hazard is addressed by the application of rock dust,inadequate rock dusting practices can leave miners exposed to an explosion *** at the National Institute for Occupational Safety and Health(NIOSH)have focused on developing a water curtain that removes FCD from the airstream,thereby reducing the buildup of FCD in mine *** this study,the number and spacing of the active sprays in the water curtain were varied to determine the optimal configuration to obtain peak knockdown efficiency(Ke)while minimizing water consumption.

关键词： Float coal dust Longwall Water spray Knockdown efficiency explosion prevention Dust control

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