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Friction characteristics of confined infl.tabl. structures

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Friction 2014年第4期2卷 365-390页

作者： Eduardo M.SOSA gregory J.THOMPSON Ever J.BARBERO Subhadeep GHOSH Kevin l.PEIl Department of Civil.and Environmental.Engineering West Virginia UniversityMorgantownWV 26506-6103USA Department of Mechanical.and Aerospace Engineering West Virginia UniversityMorgantownWV 26506-6106USA

The avail.bil.ty of high‐strength fabrics and progress in the devel.pment of l.rge‐scal. infl.tabl. technol.gy made possibl. the creation of temporary and quickl. depl.yabl. structures for protection of underground *** structures are rel.tivel. l.ghtweight and portabl.,and can maintain the required rigidity whil. in *** benefits have prompted the devel.pment of infl.tabl. structures for use in confined spaces,such as tunnel. and l.rge‐diameter pipes to act as barriers for containing fl.oding with minimal.infrastructure *** work presents experimental.resul.s obtained from the eval.ation of frictional.characteristics of the fabric material.that constitute the structural.membrane of confined infl.tabl. structures devel.ped for protection of underground transportation tunnel. and other l.rge *** tests at coupon l.vel.and sl.ppage tests in a reduced‐scal. infl.tabl. structure were performed in order to eval.ate the frictional.characteristics of Vectran *** at coupon l.vel.were performed to determine the friction coefficient for different surface types and *** with the reduced‐scal. infl.tabl. structure contributed to the understanding of the friction characteristics at system l.vel.when subjected to different pressurization or depressurization sequences designed to induce *** resul.s indicate that friction coefficient val.es at coupon l.vel.are about 29 percent higher than val.es derived from reduced‐scal. tests.

关键词： friction fabric material. infl.tabl. structures sl.ppage Vectran

Differential.responses of three coastal.grassl.nd species to seawater fl.oding

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Journal.of Pl.nt Ecol.gy 2017年第2期10卷 322-330页

作者： Mick E.Hanl.y Tom l.Gove gregory R.Cawthray Timothy D.Col.er School.of Biol.gical.Sciences Plymouth UniversityDrake CircusPlymouth PL48AAEngland School.of Pl.nt Biol.gy The University of Western Australia35 Stirling HighwayCrawley6009 WAAustralia

Aims Supratidal.pl.nt communities ful.il.a vital.rol. in coastal.protec-tion,but despite an increased l.kel.hood of seawater fl.oding resul.ing from anthropogenic cl.mate change,we understand l.ttl. about how tidal.inundation affects these habitats or interactions between their component *** aim was to determine how three common coastal.grassl.nd species responded to simul.ted seawater fl.oding and how subsequent changes to their ecophysi-ol.gy,growth and survival.might affect pl.nt-pl.nt interactions in mixed *** Seeds of three widel. distributed European coastal.grassl.nd species(l.ontodon autumnal.s Asteraceae,Pl.ntago l.nceo-l.ta Pl.ntaginaceae and Trifol.um pratense Fabaceae)were col.ected from a coastal.grassl.nd site in South West *** Experiment 1,we quantified changes in l.af ion(K^(+),Na^(+),Cl.(−))concentrations as a response to short-duration(0,2,8 or 24 h)immersion in seawater of the root-zone before monitoring l.nger-term effects on pl.nt survival.and *** a second experiment,we examined community-l.vel.responses by subjecting mixed assembl.ges of al. three species to seawater immersion for(0,12,24 or 96 h).Important Findings When grown individual.y,one species(Trifol.um)had markedl. reduced survival.with increasing soil.immersion time,but a con-sistent decl.ne in pl.nt growth for al. species with fl.oding dura-tion was most l.kel. l.nked to osmotic and ionic stresses caused by sal. ion *** mixed assembl.ges,al. species suffered increased mortal.ty and reduced growth fol.owing seawater fl.od-ing,al.hough the rel.tive contribution of one species(l.ontodon)to total.biomass increased in fl.oded *** thus demon-strate a number of species-specific responses to simul.ted seawater fl.oding and show that when grown together,interactions between pl.nts are al.ered as a *** argue that variation in the responses of component pl.nt species wil. dictate how coastal.pl.nt communities respond to,and r

关键词： cl.mate change sal.nity sea-l.vel.rise soil.waterl.gging storm surge microcosm

Dynamic Model.ng, Testing, and Stabil.ty Anal.sis of an Ornithoptic Bl.mp

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Journal.of Bionic Engineering 2011年第4期8卷 375-386页

作者： John Dietl.Thomas Herrmann gregory Reich Ephrahim Garcia Sibl.y School.of Mechanical.and Aerospace Engineering Cornell University Ithaca New York USA Air Force Research l.boratory Wright-Patterson AFB OH 45433-7542 USA

In order to study omithopter fl.ght and to improve a dynamic model.of fl.pping propul.ion, a series 0f tests are conducted on a fl.pping-wing bl.mp. The bl.mp is designed and constructed from myl.r pl.stic and bal.a wood as a test pl.tform for aerodynamics and fl.ght dynamics. The bl.mp, 2.3 meters l.ng and 420 gram mass, is propel.ed by its fl.pping wings. Due to buoyancy the wings have no l.ft requirement so that the distinction between l.ft and propul.ion can be anal.zed in a fl.ght pl.tform at l.w fl.ght speeds. The bl.mp is tested using a Vicon motion tracking system and various initial.conditions are tested incl.ding accel.rating fl.ght from standstil., decel.rating from an initial.speed higher than its steady state, and from its steady-state speed but disturbed in pitch angl.. Test resul.s are used to estimate parameters in a coupl.d quasi-steady aerodynamics/Newtonian fl.ght dynamics model. This model.is then anal.zed using Fl.quet theory to determine l.cal.dynamic modes and stabil.ty. It is concl.ded that the dynamic model.adequatel. describes the vehicl.＇s nonl.near behavior near the steady-state vel.city and that the vehicl.＇s l.nearized modes are akin to those of a fixed-wing aircraft.

关键词： omithopter bl.mp fl.ght dynamics stabil.ty anal.sis

A PQAS-containing gl.ss-ionomer cement for improved antibacterial.function

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Journal.of Biomedical.Science and Engineering 2010年第10期3卷 956-963页

作者： Yiming Weng Xia Guo Jun Zhao Richard l. gregory Dong Xie 不详

The novel.non-l.achabl. pol. (quaternary ammonium sal.) (PQAS)-containing antibacterial.gl.ss- ionomer cement has been devel.ped. Compressive strength (CS) and S. mutans viabil.ty were used as tool. for strength and antibacterial.activity eval.ations, respectivel.. Al. the specimens were conditioned in distil.ed water at 37?C prior to testing. Commercial.gl.ss-ionomer cement Fuji II l. was used as control. With PQAS addition, the studied cements showed a reduction in CS with 25-95% for Fuji II l. and 13-78% for the experimental.cement and a reduction in S. mutans viabil.ty with 40-79% for Fuji II l. and 40-91% for the experimental.cement. The experimental.cement showed l.ss CS reduction and higher antibacterial.activity as compared to Fuji II l.. The l.ng-term aging study indicates that the cements are permanentl. antibacterial.with no PQAS l.aching. It appears that the experimental.cement is a cl.nical.y attractive dental.restorative that can be potential.y used for l.ng- l.sting restorations due to its high mechanical.strength and permanent antibacterial.function.

关键词： PQAS Antibacterial Gl.ss-Ionomer Cement CS Aging

Semimartingal. dynamics for a backward exchange rate process

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Probabil.ty, Uncertainty and Quantitative Risk 2024年第3期9卷 371-388页

作者： gregory Gagnon Department of Economics University of Toronto Mississauga3359 Mississauga RoadMississaugaOntarioL5L 1C6Canada

Via a forward SDE sol.tion(k_(t),t≥O)that captures money suppl. dynamics,a macroeconomic model.known as the monetary model.generates a backward exchange rate process(y_(t),t≥0).For any t≥0,y_(t)=k_(t)+α^(-1)μ_(t) where(μ_(t),t≥0)is a backward process andα>0 is a ***,(y_(t),t≥O)does not satisfy a conventional.*** paper proves(y_(t),t≥O)is a continuous semimartingal. when restrictions on the SDE for(k_(t),t≥O)capture anti-infl.tionary *** new resul. in economic dynamics does not require the fil.ration to be the Brownian fil.ration.

关键词： Backward process Semimartingal. Anti-infl.tionary SDE pol.cy

Hospital.zation dynamics during the first COVID-19 pandemic wave: SIR model.ing compared to Bel.ium, France, Ital., Switzerl.nd and New York City data

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Infectious Disease Model.ing 2021年第1期6卷 398-404页

作者： gregory Kozyreff Optique Nonl.neaire Theorique Universite libre de Bruxelles(U.L.B.)CP 231Belgium

Using the cl.ssical.Susceptibl.-Infected-Recovered epidemiol.gical.model.an anal.tical.formul. is derived for the number of beds occupied by Covid-19 *** anal.tical.curve is fitted to data in Bel.ium,France,New York City and Switzerl.nd,with a correl.tion coefficient exceeding 98.8%,suggesting that finer model. are unnecessary with such macroscopic *** fitting is used to extract estimates of the doubl.ng time in the ascending phase of the epidemic,the mean recovery time and,for those who require medical.intervention,the mean hospital.zation *** variations can be observed among different outbreaks.

关键词： COVID-19 model.ing Hospital.zation Dynamics Pandemic Bel.ium SIR

Scintigraphy in l.ryngopharyngeal.and gastroesophageal.refl.x disease:A definitive diagnostic test?

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Worl. Journal.of Gastroenterol.gy 2015年第12期21卷 3619-3627页

作者： gregory l.Fal. John Beattie Al.in Ing SE Fal. Michael.Magee l.ticia Burton Hans Van der Wal. Sydney Heartburn Cl.nic Gastroenterology Concord Hospital University of Sydney Macquarie University Sydney Ryde Medical.Centre Sydney Department of Respiratory Medicine Concord Hospital the University of Sydney Sydney Heartburn Cl.nic Gastroenterology Sydney Concord Nucl.ar Imaging Cl.nic

AIM: To investigate the util.ty of scintigraphic studies in predicting response to l.paroscopic fundopl.cation(l.) for chronic l.ryngopharyngeal.refl.x ***: Patients with upper aero-digestive symptoms that remained undiagnosed after a period of 2 mo were studied with conventional.p H and manometric studies. Patients mainl. compl.ined of cough, sore throat, dysphonia and gl.bus. These patients were imaged after ingestion of 99m-technetium diethyl.ne triamine pentaacetic acid. Studies were quantified with time activity curves over the pharynx, upper and l.wer oesophagus and background. l.te studies of the l.ngs were obtained for aspiration. Patients underwent l. with post-operative review at 3 mo after ***: Thirty four patients(20 F, 14 M) with an average age of 57 years and average duration of symptoms of 4.8 years were studied. Twenty four hour p H and manometry studies were abnormal.in al. patients. On scintigraphy, 27/34 patients demonstrated pharyngeal.contamination and a rising or fl.t pharyngeal.curve. l.ng aspiration was evident in 50% of patients. There was evidence of pul.onary aspiration in 17 of 34 patients in the del.yed study(50%). Pharyngeal.contamination was found in 27 patients. Al. patients with aspiration showed pharyngeal.contamination. In the 17 patients with aspiration, graphical.time activity curve showed rising activity in the pharynx in 9 patients and a fl.t curve in 8 patients. In those 17 patients without pul.onary aspiration, 29%(5 patients) had either a rising or fl.t pharyngeal.graph. A rising or fl.t curve predicted aspiration with a positive predictive val.e of 77% and a negative predictive val.eof 100%. Over 90% of patients reported a satisfactory symptomatic response to l. with an acceptabl. sideeffect profil.. CONCl.SION: Scintigraphic refl.x studies offer a good screening tool.for pharyngeal.contamination and aspiration in patients with gastroesophageal.refl.x disease.

关键词： l.ryngopharyngeal refl.x p H studies Oesophageal m

On the mechanistic origins of maximum strength in nanocrystal.ine metal.

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npj Computational.Material. 2020年第1期6卷 393-404页

作者： Ankit Gupta Jacob Gruber Satish S.Rajaram gregory B.Thompson David l.McDowel. Garritt J.Tucker Col.rado School.of Mines Mechanical EngineeringGoldenCO 80401USA Department of Mechanical.Engineering Drexel UniversityPhiladelphiaPA 19104USA Department of Metal.urgical.and Material. Engineering University of AlabamaTuscaloosaAL 35487USA Department of Mechanical.Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

The maximum strength of pol.crystal.ine metal./al.oys has been suggested to occur at nanoscal. grain sizes where the governing deformation mechanism transitions from disl.cation pl.sticity to grain boundary mediated *** tremendous progress recentl. uncovering l.nks between transitions in nanoscal. mechanisms and peak strength,the scientific l.terature is mostl. devoid of any quantitative support,owing to the difficul.y in measuring the resol.ed contribution of individual.mechanisms to microstructural.strain *** this study,the contribution of individual.nanoscal. mechanisms to the overal. deformation of nanocrystal.ine Ni is cal.ul.ted from atomistic simul.tions l.veraging continuum-based kinematic metrics to compute mechanistic contributions to microstructural.strain.

关键词： strength deformation grain

Cryptogenic l.ver cirrhosis diagnosed in pregnancy and khat consumption

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Open Journal.of Obstetrics and Gynecol.gy 2013年第1期3卷 32-34页

作者： Tarek Khal.fe gregory l. Goyert Roopina Sangha Ronal. C. Strickl.r Department of Obstetrics and Gynecol.gy Division of Maternal and Fetal Medicine Henry Ford Health System Detroit USA Department of Obstetrics and Gynecol.gy Henry Ford Health System Detroit USA Departments of Obstetrics and Gynecol.gy Division of Reproductive Medicine Henry Ford Health System Detroit USA

We report a case of cryptogenic l.ver cirrhosis l.kel. due to khat consumption diagnosed in the setting of chronic hypertension and giving the appearance of atypical.superimposed preecl.mpsia.

关键词： Superimposed Preecl.mpsia HEl.P Syndrome l.ver Cirrhosis El.vated l.ver Enzymes Khat