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Assessment of pipeline stability in the Gulf of Mexico during hurricanes using dynamic analysis

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Theoretical & Applied Mechanics Letters 2015年第2期5卷 74-79页

作者： Yinghui Tian Bassem Youssef mark j.Cassidy Centre for Offshore Foundation Systems and ARC CoE for Geotechnical Science and Engineering University of Western Australia Atteris Level 3220 St Georges TerracePerthWA6000Australia

Pipelines are the critical link between major offshore oil and gas developments and the mainland. Any inadequate on-bottom stability design could result in disruption and failure, having a devastating impact on the economy and environment. Predicting the stability behavior of offshore pipelines in hurricanes is therefore vital to the assessment of both new design and existing assets. The Gulf of Mexico has a very dense network of pipeline systems constructed on the seabed. During the last two decades, the Gulf of Mexico has experienced a series of strong hurricanes, which have destroyed, disrupted and destabilized many pipelines. This paper first reviews some of these engineering cases. Following that, three case studies are retrospectively simulated using an in-house developed program. The study utilizes the offshore pipeline and hurricane details to conduct a Dynamic Lateral Stability analysis, with the results providing evidence as to the accuracy of the modeling techniques developed.

关键词： Pipeline On-bottom stability Dynamic lateral stability analysis Force-resultant model Hydrodynamic load

Single droplet drying of detergents:Experimentation and modelling

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Particuology 2021年第5期19卷 35-47页

作者： Borja Hernandez Rosa Mondragon mark A.Pintoa Leonor Hernandez j.Enrique julia juan Carlos jarque Sergio Chiva Mariano Martin Newcastle Innovation Centre Procter&Gamble R&DNewcastle upon TyneUK Departamento de Ingenieria Quimica y Textil.Universidad de Salamanca SalamancaSpain Departamento de Ingenieria Mecanica y Construccion Universitat Jaume ICastellon de la PlanaSpain Instituto de Tecnologia Ceramica Universitat Jaume ICastellon de la PlanaSpain

This study evaluates the single droplet drying(SDD)of *** data are used to validate a theoretical multistage *** experiments are carried out in an acoustic levitator analysing six different detergent formulations at 393 *** work is completed by developing a model based on conservation *** model is composed of the three stages observed in the drying *** the first stage,an external surface drying stage occurs until the surface is saturated and the crust is *** the next stage,the drying rate is governed by diffusion through the *** the same time,the particle heats up until boiling conditions are achieved in the core of the *** this point,the third stage *** the final stage,the droplet core is in boiling conditions which are governed by the pressure drop through the crust and the concentration of *** model has been evaluated for the different formulations being flexible to predict the drying of different mixtures with good accuracy.

关键词： Drying Single droplet Acoustic levitator Detergents

Sex-specific differences in white matter microvascular integrity after ischaemic stroke

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Stroke & Vascular Neurology 2019年第4期4卷 198-205页

作者： mark R Etherton Ona Wu Pedro Cougo Svetlana Lorenzano Hua Li Lisa Cloonan mark j R j Bouts Arne Lauer Ken Arai Eng H Lo Steve K Feske Karen L Furie Natalia S Rost Department of Neurology Massachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA Martinos Center for Biomedical Imaging Massachusetts General HospitalCharlestownMAUnited States Department of Radiology Massachusetts General Hospital and Harvard Medical SchoolBostonMAUnited States Medical School of Ribeirao Preto University of Sao PauloSao PauloBrazil Department of Human Neurosciences Sapienza University of RomeRomeItaly Institute of Psychology Leiden UniversityLeidenNetherlands Department of Neuroradiology Goethe-Universitat Frankfurt am MainFrankfurtGermany Department of Neurology Brigham and Women’s Hospital and Harvard Medical SchoolBostonMAUnited States Department of Neurology Warren Alpert Medical School of Brown UniversityProvidenceRhode IslandUSA

background and purpose Functional outcomes after ischaemic stroke are worse in women,despite adjusting for differences in comorbidities and treatment *** matter microvascular integrity represents one risk factor for poor long-term functional outcomes after ischaemic *** aim of the study is to characterise sex-specific differences in microvascular integrity in individuals with acute ischaemic *** A retrospective analysis of subjects with acute ischaemic stroke and brain MRI with diffusion-weighted(DWI)and dynamic-susceptibility contrast-enhanced(DSC)perfusion-weighted imaging obtained within 9 hours of last known well was *** the hemisphere contralateral to the acute infarct,normal-appearing white matter(NAWM)microvascular integrity was measured using the K_(2) coefficient and apparent diffusion coefficient(ADC)*** analyses for predictors of K_(2) coefficient,DWI volume and good outcome(90-day modified Rankin scale(mRS)score<2)were *** 105 men and 79 women met inclusion criteria for *** no difference in age,women had increased NAWM K_(2) coefficient(1027.4 vs 692.7×10^(-6)/s;p=0.006).In women,atrial fibrillation(β=583.6;p=0.04)and increasing NAWM ADC(β=4.4;p=0.02)were associated with increased NAWM K_(2) *** multivariable regression analysis,the K_(2) coefficient was an independent predictor of DWI volume in women(β=0.007;p=0.01)but not *** In women with acute ischaemic stroke,increased NAWM K_(2) coefficient is associated with increased infarct volume and chronic white matter structural *** studies investigating sex-specific differences in white matter microvascular integrity are needed.

关键词： microvascular white coefficient

Calibration of coupled hydro-mechanical properties of grain-based model for simulating fracture process and associated pore pressure evolution in excavation damage zone around deep tunnels

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journal of Rock Mechanics and Geotechnical Engineering 2021年第1期13卷 60-83页

作者： Kiarash Farahmand mark S.Diederichs Department of Geological Sciences and Geological Engineering Queen’s UniversityKingstonOntarioK7L 3N6Canada Golder Associates VancouverBritish ColumbiaCanada

The objective of this paper is to develop a methodology for calibration of a discrete element grain-based model(GBM)to replicate the hydro-mechanical properties of a brittle rock measured in the laboratory,and to apply the calibrated model to simulating the formation of excavation damage zone(EDZ)around underground ***,a new cohesive crack model is implemented into the universal distinct element code(UDEC)to control the fracturing behaviour of materials under various loading ***,a methodology for calibration of the components of the UDEC-Voronoi model is *** role of connectivity of induced microcracks on increasing the permeability of laboratory-scale samples is *** calibrated samples are used to investigate the influence of pore fluid pressure on weakening the drained strength of the laboratory-scale *** validity of the Terzaghi’s effective stress law for the drained peak strength of low-porosity rock is tested by performing a series of biaxial compression test ***,the evolution of damage and pore pressure around two unsupported circular tunnels in crystalline granitic rock is studied.

关键词： Coupled hydro-mechanical properties Excavation damage zone(EDZ) Grain-based model(GBM)calibration Stress-fracturing of rock Cohesive crack model Stress-dependent permeability

Innovative approaches to genome editing in avian species

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journal of Animal Science and Biotechnology 2018年第2期9卷 278-284页

作者： Caitlin A.Cooper Timothy j.Doran Arjun Challagulla mark L.V.Tizard Kristie A.jenkins CSIRO Health and Biosecurity Australian Animal Health Laboratory

The tools available for genome engineering have significantly improved over the last 5 years, allowing scientist to make precise edits to the genome. Along with the development of these new genome editing tools has come advancements in technologies used to deliver them. In mammals genome engineering tools are typically delivered into in vitro fertilized single cell embryos which are subsequently cultured and then implanted into a recipient *** avian species this is not possible, so other methods have been developed for genome engineering in birds. The most common involves in vitro culturing of primordial germ cells(PGCs), which are cells that migrate through the embryonic circulatory system to the developing gonad and colonize the gonad, eventually differentiating into the gonadocytes which produce either sperm or ova. While in culture the PGCs can be modified to carry novel transgenes or gene edits, the population can be screened and enriched, and then transferred into a recipient embryo. The largest drawback of PGC culture is that culture methods do not transfer well across avian species, thus there are reliable culture methods for only a few species including the chicken. Two newer technologies that appear to be more easily adapted in a wider range of avian species are direct injection and sperm transfection assisted gene editing(STAGE).The direct injection method involves injecting genome engineering tools into the circulatory system of the developing embryo just prior to the developmental time point when the PGCs are migrating to the gonads. The genome engineering tools are complexed with transfection reagents, allowing for in vivo transfection of the PGCs. STAGE utilizes sperm transfection to deliver genome engineering tools directly to the newly fertilized embryo. Preliminary evidence indicates that both methodologies have the potential to be adapted for use in birds species other than the chicken, however further work is needed in this area.

关键词： Avian CRISPR Genome engineering PGCs Sperm TALEN

Best practices for electrochemical characterization of supercapacitors

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journal of Energy Chemistry 2023年第5期80卷 265-283,I0007页

作者： joão Pedro Aguiar dos Santos Fernando Cesar Rufino joǎo IYutaka Ota Rodolfo CFernandes Rafael Vicentini Cesar jBPagan Leonardo Morais Da Silva hudson Zanin Brazilian Renewable Energies Center for Innovation on New EnergiesSchool of Electrical and Computer EngineeringUniversity of CampinasSP 13083-852Brazil School of Electrical and Computer Engineering University of CampinasSP 13083-852Brazil Department of Chemistry Laboratory of Fundamental and Applied ElectrochemistryFederal University of Jequitinhonha e Mucuri's ValleyRodovia MGT 367km 5835000Alto da Jacuba39100-000 DiamantinaMGBrazil

We discuss here essential aspects of the experimental supercapacitors characterization by a series of well-known electrochemical *** are motivated by a considerable number of publications that misreport procedures and *** often conceal or neglect essential information about the electrochemical analytical apparatus used and its *** lack of such information may lead researchers,especially inexperienced ones,to misunderstand the procedures and ***,the misled electrochemical equipment configuration favors misinterpretation of data and low reproducibility *** paper aims to highlight these issues and clarify *** explain fundamental concepts of some electrochemical analytical methods,such as cyclic voltammetry,galvanostatic charge-discharge,single potential step chronoamperometry,and electrochemical impedance spectroscopy,focusing on the supercapacitor *** configurations of electrical parameters are presented and discussed to highlight the effects of incorrect setup and uncover misleading *** discuss how the electrochemical setup and data analyses matter in reliable data results for the supercapacitor.

关键词： Supercapacitor Electrochemical instrumentation Electrochemical methods Electrochemistry

Cadmium isotope fractionation reveals genetic variation in Cd uptake and translocation by Theobroma cacao and role of natural resistanceassociated macrophage protein 5 and heavy metal ATPase-family transporters

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Horticulture Research 2020年第1期7卷 2006-2016页

作者： Rebekah E.T.Moore Ihsan Ullah Vinicius Hde Oliveira Samantha j.Hammond Stanislav Strekopytov mark Tibbett jim M.Dunwell mark Rehkämper Department of Earth Science and Engineering Imperial CollegeLondon SW72BPUK School of Agriculture Policy and DevelopmentUniversity of ReadingReading RG66BZUK School of Environment Earth and Ecosystem SciencesThe Open UniversityMilton Keynes MK76AAUK Imaging and Analysis Centre The Natural History MuseumLondon SW75BDUK Present address:Department of Plant Biology Institute of BiologyUniversity of CampinasCampinasSao Paulo 13083-970Brazil Present address:National Measurement Laboratory LGCQueen’s RoadTeddington TW110LYUK

In response to new European Union regulations,studies are underway to mitigate accumulation of toxic cadmium(Cd)in cacao(Theobroma cacao,Tc).This study advances such research with Cd isotope analyses of 19 genetically diverse cacao clones and yeast transformed to express cacao natural resistance-associated macrophage protein(NRAMP5)and heavy metal ATPases(HMAs).The plants were enriched in light Cd isotopes relative to the hydroponic solution withΔ^(114/110)Cd_(tot-sol)=−0.22±0.08‰.Leaves show a systematic enrichment of isotopically heavy Cd relative to total plants,in accord with closed-system isotope fractionation ofΔ^(114/110)C_(dseq-mob)=−0.13‰,by sequestering isotopically light Cd in roots/stems and mobilisation of remaining Cd to *** findings demonstrate that(i)transfer of Cd between roots and leaves is primarily unidirectional;(ii)different clones utilise similar pathways for Cd sequestration,which differ from those of other studied plants;(iii)clones differ in their efficiency of Cd *** yeast that expresses TcNRAMP5(*** natural resistance-associated macrophage gene)had isotopically lighter Cd than did *** suggests that NRAMP5 transporters constitute an important pathway for uptake of Cd by *** isotope signatures of transgenic yeast expressing HMA-family proteins suggest that they may contribute to Cd *** data are the first to record isotope fractionation induced by transporter proteins in vivo.

关键词： roots transformed signature

Development of a fault-rupture environment in 3D: A numerical tool for examining the mechanical impact of a fault on underground excavations

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International journal of Mining Science and Technology 2019年第1期29卷 105-111页

作者： Bo-Hyun Kim mark K.Larson Spokane Mining Research Division CDC/NIOSH

While faults are commonly simulated as a single planar or non-planar interface for a safety or stability analysis in underground mining excavation, the real 3D structure of a fault is often very complex, with different branches that reactivate at different times. Furthermore, these branches are zones of nonzero thickness where material continuously undergoes damage even during interseismic periods. In this study, the initiation and the initial evolution of a strike-slip fault was modeled using the FLAC3D software program. The initial and boundary conditions are simplified, and mimic the Riedel shear experiment and the constitutive model in the literature. The FLAC3D model successfully replicates and creates the 3D fault zone as a strike-slip type structure in the entire thickness of the model. The strike-slip fault structure and normal displacement result in the formation of valleys in the model. Three panels of a longwall excavation are virtually placed and excavated beneath a main valley. The characteristics of stored and dissipated energy associated with the panel excavations are examined and observed at different stages of shear strain in the fault to evaluate bump potential. Depending on the shear strain in the fault, the energy characteristics adjacent to the longwall panels present different degrees of bump potential, which is not possible to capture by conventional fault simulation using an interface.

关键词： 3D fault zone Strike-slip fault FLAC3D Bump potential Energy characteristics

Eight decades of compositional change in a managed northern hardwood landscape

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Forest Ecosystems 2023年第3期10卷 398-410页

作者： mark j.Ducey Olivia L.Fraser Mariko Yamasaki Ethan P.Belair William B.Leak University of New Hampshire Department of Natural Resources and the Environment114 James HallDurhamNH03824USA U.S.D.A.Forest Service White Mountain National Forest71 White Mountain DriveCamptonNH03223USA U.S.D.A.Forest Service Northern Research Station271 Mast RoadDurhamNH03824USA The Nature Conservancy Natural Climate SolutionsAfrica Regional Portland Office45 Exchange StSuite 303PortlandME04101USA

We analyzed over 8 decades of change in forest composition(represented by species proportion of basal area)and size class from more than 400 permanent plots located on the Bartlett Experimental Forest in the White Mountains of New *** data represent one of the longest-term landscape-scale records of forest change based on permanent plots in North *** analyzed the plots based on elevation class,land type indicating assumed successional direction(grouped into coniferous and deciduous),and inventory period within managed and unmanaged portions of the *** ongoing shift from small-to large-diameter stems is clear across all species,in response to the overall aging of the forest following exploitative harvesting in the 19th *** compositional changes include a continuing decline in shade-intolerant species(paper birch and aspen),along with the mid-tolerant yellow *** increase in red maple abundance through the early 1990s has leveled off or *** shade-tolerant species,increases in beech and red spruce were largely consistent with assumed land type on unmanaged plots,but heavy marking against diseased beech on managed plots restricted increase of that *** maple declined in abundance except where silvicultural intervention helped maintain *** contrast,eastern hemlock showed a continuing expansion at all elevations below 600 *** data continue to show little or no evidence of upward migration of species,despite evidence of recent regional change in ***,the BEF is poised for substantial changes when emerald ash borer and hemlock woolly adelgid,both of which are known to infest nearby areas,do arrive.

关键词： Northern hardwoods Succession Stand dynamics Silviculture