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Friction 2024年第6期12卷 1283-1298页

作者： Junhyeon SEO Prahalada RAO Bart RAEYMAEKERS Department of Mechanical Engineering Virginia TechBlacksburgVA 24061USA Grado Department of Industrial and Systems Engineering Virginia TechBlacksburgVA 24061USA

Numerically generating synthetic surface topography that closely resembles the features and characteristics of experimental surface topography measurements reduces the need to perform these intricate and costly ***,existing algorithms to numerically generated surface topography are not well-suited to create the specific characteristics and geometric features of as-built surfaces that result from laser powder bed fusion(LPBF),such as partially melted metal particles,porosity,laser scan lines,and ***,we present a method to generate synthetic as-built LPBF surface topography maps using a progressively growing generative adversarial *** qualitatively and quantitatively demonstrate good agreement between synthetic and experimental as-built LPBF surface topography maps using areal and deterministic surface topography parameters,radially averaged power spectral density,and material ratio *** ability to accurately generate synthetic as-built LPBF surface topography maps reduces the experimental burden of performing a large number of surface topography ***,it facilitates combining experimental measurements with synthetic surface topography maps to create large data-sets that facilitate,*** as-built surface topography to LPBF process parameters,or implementing digital surface twins to monitor complex end-use LPBF parts,amongst other applications.

关键词： additive manufacturing surface topography synthetic surface topography generative adversarial networks

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World Journal of Otorhinolaryngology-Head and Neck Surgery 2024年第2期10卷 97-104页

作者： Mihai A.Bentan Evan R.Reiter Richard M.Costanzo Daniel H.Coelho Department of Otolaryngology-Head&Neck Surgery Virginia Commonwealth University School of MedicineRichmondVirginiaUSA

Objective:The aim of this study was to review findings from a large prospective national database of chemosensory disturbances associated with coronavirus disease 2019(COVID-19)*** Sources:The virginia Commonwealth university Smell and Taste Center national database of COVID-19 chemosensory ***:A series of online surveys,first opened on April 10,2020,was made accessible nationwide to any adult with sudden chemosensory dysfunction since January *** received subsequent follow-up surveys 14 days,1 month,3 months,and 6 months after *** additional survey was sent to all participants on May 28,2022 to assess long-term *** pertaining to demographics,symptoms,comorbidities,treatments,and life impact was ***:Of 363 participants who reported complete smell recovery,51.2%recovered within 1 month,70%within 3 months,and 79%within 6 months,while 8.8%took over 1 year to completely *** all participants,7.5%had no smell *** predictors of recovery included age<40,male gender,and the presence of nasal *** predictors included difficulty breathing and prior head *** participants reported a decrease in quality of life and the presence of potential safety hazards associated with decreased smell ***:Most subjects with COVID-19-related chemosensory dysfunction recover,with the majority noting complete recovery within weeks of *** aged over 40 years and female gender were associated with lower rates of recovery.A considerable number of participants reported significant impact on quality of life and safety.

关键词： anosmia COVID-19 smell

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Understanding poromechanical response of a biogenic coalbed methane reservoir

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International Journal of Coal Science & Technology 2024年第3期11卷 32-50页

作者： Rohit Pandey Satya Harpalani virginia Tech BlacksburgUSA Southern Illinois university CarbondaleUSA

Biogenic coalbed methane(BCBM)reservoirs aim to produce methane from in situ coal deposits following microbial conversion of *** of BCBM reservoirs requires economic methane production within an acceptable *** work reported here quantifies the findings of previously published qualitative work,where it was found that bioconversion induces strains in the pore,matrix and bulk *** imaging and dynamic strain monitoring techniques,the bioconversion induced strain is quantified *** understand the effect of these strains from a reservoir geomechanics perspective,a corresponding poromechanical model is ***,findings of imaging experiments are validated using core-flooding flow ***,expected field-scale behavior of the permeability response of a BCBM operation is modeled and *** results of the study indicated that,for Illinois coals,bioconversion induced strains result in a decrease in fracture porosity,resulting in a detrimental permeability drop in excess of 60%during bioconversion,which festers itself exponentially throughout its producing *** indicate that reservoirs with high initial permeability that will support higher Darcian flowrates,would be better suited for coal bioconversion,thereby providing a site-selection criteria for BCBM operations.

关键词： Coal bioconversion Poromechanical model Reservoir response Bioconversion induced strain

Advancing respirable coal mine dust source apportionment:a preliminary laboratory exploration of optical microscopy as a novel monitoring tool

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International Journal of Coal Science & Technology 2024年第2期11卷 222-233页

作者： Nestor Santa Emily Sarver Department of Mining and Minerals Engineering Virginia TechBlacksburgVA 24061USA

Exposure to respirable coal mine dust(RCMD)can cause chronic and debilitating lung ***-time monitoring capabilities are sought which can enable a better understanding of dust components and *** many underground mines,RCMD includes three primary components which can be loosely associated with three major dust sources:coal dust from the coal seam itself,silicates from the surrounding rock strata,and carbonates from the inert‘rock dust’products that are applied to mitigate explosion hazards.A monitor which can reliably partition RCMD between these three components could thus allow source *** tracking silicates,specifically,could be valuable since the most serious health risks are typically associated with this component-particularly if abundant in crystalline *** a monitoring concept based on field microscopy,and following up on prior research using polarized light,the aim of the current study was to build and test a model to classify respirable-sized particles as either coal,silicates,or *** model development,composite dust samples were generated in the laboratory by successively depositing dust from high-purity materials onto a sticky transparent substrate,and imaging after each deposition event such that the identity of each particle was known a *** testing followed a similar approach,except that real geologic materials were used as the source for each dust *** showed that the model had an overall accuracy of 86.5%,indicating that a field-microscopy based moni-tor could support RCMD source apportionment and silicates tracking in some coal mines.

关键词： Polarized light microscopy Image processing Dust monitoring Respirable silica Coal mining

Comparisons of oxbow lake fish assemblages in relation to bigheaded carp establishment in the lower White River, Arkansas

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Ecological Processes 2024年第1期13卷 188-205页

作者： Michael A.Eggleton Cody J.Salzmann Joseph E.Kaiser Shannon C.F.Smith Department of Aquaculture and Fisheries University of Arkansas at Pine Bluff Arkansas Game and Fish Commission virginia Institute of Marine Science

Background Since the late 1990s, bigheaded carps(largely silver carp [Hypophthalmichthys molitrix] but also bighead carp [H. nobilis]) have established throughout the lower Mississippi River basin. Using previously studied oxbow lakes in the lower White River basin, Arkansas, we compared current(2017, “post-carp” establishment) fish assemblages to historical(2002, “pre-carp” establishment) fish assemblages. Fish assemblages were comprehensively assessed using multiple gears, including boat electrofishing, mini-fyke nets, and experimental small-mesh gill *** T-tests suggested that fish assemblage indices of richness, diversity, evenness, and dominance were often greater(P 0.05) between the pre-carp and post-carp period with fish assemblages depicted using mini-fyke nets. Nonmetric multidimensional scaling analyses indicated that fish assemblages differed structurally between pre-carp and post-carp periods. Assemblage differences were linked to both small and large abundance changes for more than 20 species. Abundances of gizzard shad(Dorosoma cepedianum), emerald shiner(Notropis atherinoides), pugnose minnow(Opsopoeodus emiliae), crappies(Pomoxis spp.), bluegill(Lepomis macrochirus), orangespotted sunfish(L. humilis), and yellow bass(Morone mississippiensis) declined between the pre-carp and postcarp periods. Conversely, abundances of weed shiner(N. texanus), pallid shiner(Hybopsis amnis), longear sunfish(L. megalotis), buffalofishes(Ictiobus spp.), and gars(Lepisosteus spp.) generally increased during the same *** Although not possible to conclude assemblage shifts were entirely related to bigheaded carps due to the absence of an appropriate reference system where carps did not establish, the wide establishment of these carps is one of the most pervasive changes to have occurred in the lower White

关键词： Bigheaded carp Silver carp Aquatic nuisance species Fish assemblage Oxbow lake Large river

Structural engineered living materials

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Nano Research 2024年第2期17卷 715-733页

作者： Yang Geng Zian Jia Ling Li 635 Prices Fork Road Department of Mechanical EngineeringVirginia Polytechnic Institute and State UniversityBlacksburg VA24061USA

Biological structural materials not only exhibit remarkable mechanical properties but also often embody dynamic characteristics such as environmental responsiveness,autonomy,and self-healing,which are difficult to achieve in conventional engineering *** merging materials science,synthetic biology,and other disciplines,engineered living materials(ELMs)provide a promising solution to combine living organisms with abiotic components,thus facilitating the construction of functional“living”*** natural materials,ELMs possess vitality and hold immense application potential in areas such as medicine,electronics,and construction,captivating increasing research attention *** an emerging branch of ELMs,structural ELMs aim to mimic living biological structural materials by achieving desired mechanical performance while maintaining important“living”*** we summarize the recent progress and provide our perspectives for this emerging research *** first summarize the superiority of structural ELMs by reviewing biological structural materials and biomimetic material design ***,we provide a systematic discussion on the definition and classifications of structural ELMs,their mechanical performance,and physiological ***,we summarize some critical challenges faced by structural ELMs and highlight directions of future *** hope this review article can provide a timely summary of the state of the art and relevant perspectives for future development of structural ELMs.

关键词： structural materials engineered living materials(ELMs) structural ELMs composites mechanical properties

Dissociation cross sections ofψ(3770),ψ(4040),ψ(4160),andψ(4415)mesons with nucleons

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Communications in Theoretical Physics 2024年第4期76卷 93-112页

作者： Ruo-Qing Ding Xiao-Ming Xu H J Weber Department of Physics Shanghai UniversityBaoshanShanghai 200444China Department of Physics University of VirginiaCharlottesvilleVA 22904United States of America

We study the dissociation of ψ(3770), ψ(4040), ψ(4160), and ψ(4415) mesons in collision with nucleons, which takes place in high-energy proton-nucleus collisions. The quark interchange between a nucleon and a ■ meson leads to the dissociation of the ■ meson. We consider the reactions:■, and■, where R stands for ψ(3770), ψ(4040), ψ(4160), or ψ(4415). A reaction of a neutron and a ■ meson corresponds to a reaction of a proton and the ■ meson by replacing the up quark with the down quark and vice versa. Transition-amplitude formulas are derived from the S-matrix *** cross sections are calculated with the transition amplitudes for scattering in the prior form and in the post form. The cross sections relate to nodes in the radial wave functions of ψ(3770), ψ(4040), ψ(4160), and ψ(4415) mesons.

关键词： inelastic nucleon-charmonium scattering quark interchange relativistic constituent quark potential model

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Monocyte and macrophage function in respiratory viral infections

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Animal Diseases 2024年第1期4卷 40-47页

作者： Mohd Arish Jie Sun Beirne B.Carter Center for Immunology Research University of VirginiaCharlottesvilleVA 22908USA Division of Infectious Disease and International Health Department of MedicineUniversity of VirginiaCharlottesvilleVA 22908USA

Pulmonary macrophages,such as tissue-resident alveolar and interstitial macrophages and recruited monocyte-derived macrophages,are the major macrophages present in the lungs during homeostasis and diseased *** tissue-resident macrophages act as sentinels of the alveolar space and play an important role in maintaining homeostasis and immune regulation,recruited macrophages accumulate in the respiratory tract after acute viral *** sharing similar anatomical niches,these macrophages are distinct in terms of their origins,surface marker expression,and transcriptional profiles,which impart macrophages with distinguished characteristics in physi-ological and pathophysiological *** this review,we summarize the current view on these macrophage populations,their shared functions,and what makes them distinct from each other in the context of homeostasis andrespiratoryviral infections.

关键词： Alveolar macrophages Interstitial macrophages Monocytes derived macrophages Viral infection IAV RSV SARS-COV-2

Least Square Finite Element Model for Analysis of Multilayered Composite Plates under Arbitrary Boundary Conditions

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World Journal of Engineering and Technology 2024年第1期12卷 40-64页

作者： Christian Mathew Yao Fu Department of Engineering Mechanics Virginia Polytechnic Institute and State University Blacksburg Virginia USA Department of Aerospace and Ocean Engineering Virginia Polytechnic Institute and State University Blacksburg Virginia USA

Laminated composites are widely used in many engineering industries such as aircraft, spacecraft, boat hulls, racing car bodies, and storage tanks. We analyze the 3D deformations of a multilayered, linear elastic, anisotropic rectangular plate subjected to arbitrary boundary conditions on one edge and simply supported on other edge. The rectangular laminate consists of anisotropic and homogeneous laminae of arbitrary thicknesses. This study presents the elastic analysis of laminated composite plates subjected to sinusoidal mechanical loading under arbitrary boundary conditions. Least square finite element solutions for displacements and stresses are investigated using a mathematical model, called a state-space model, which allows us to simultaneously solve for these field variables in the composite structure’s domain and ensure that continuity conditions are satisfied at layer interfaces. The governing equations are derived from this model using a numerical technique called the least-squares finite element method (LSFEM). These LSFEMs seek to minimize the squares of the governing equations and the associated side conditions residuals over the computational domain. The model is comprised of layerwise variables such as displacements, out-of-plane stresses, and in- plane strains, treated as independent variables. Numerical results are presented to demonstrate the response of the laminated composite plates under various arbitrary boundary conditions using LSFEM and compared with the 3D elasticity solution available in the literature.

关键词： Multilayered Composite and Sandwich Plate Transverse Stress Continuity Condition Arbitrary Boundary Condition Layerwise Theory Least-Squares Formulation

The Global Energy and Water Exchanges(GEWEX)Project in Central Asia:The Case for a Regional Hydroclimate Project

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Advances in Atmospheric Sciences 2024年第5期41卷 777-783页

作者： Michael BRODY Maksim KULIKOV Sagynbek ORUNBAEV Peter J.VAN OEVELEN International Agricultural university Tashkent 111200Uzbekistan George Mason university FairfaxVirginia 22030USA university of Central Asia Bishkek 720001Kyrgyz Republic American university of Central Asia Bishkek 720060Kyrgyz Republic International GEWEX project George Mason UniversityFairfaxVirginia 22030USA

Central Asia consists of the former Soviet Republics,Kazakhstan,Kyrgyz Republic,Tajikistan,Turkmenistan,and *** region’s climate is continental,mostly semi-arid to *** is a significant part of the region’s *** its nature of intensive water use,agriculture is extremely vulnerable to climate *** growth and irrigation development have significantly increased the demand for water in the *** climate change issues include melting glaciers and a shrinking snowpack,which are the foundation of the region’s water resources,and a changing precipitation *** glaciers are located in Kyrgyzstan and Tajikistan,leading to transboundary water resource *** already has extremely high *** indicate that Central Asia has been warming and precipitation might be *** warming is expected to increase,but its spatial and temporal distribution depends upon specific global *** of future precipitation show significant uncertainties in type,amount,and *** Hydroclimate Projects(RHPs)are an approach to studying these *** steps to develop an RHP began in 2021 with a widely distributed online survey about these climate *** was followed up with an online workshop and then,in 2023,an in-person workshop,held in Tashkent,*** for the Global Energy and Water Exchanges(GEWEX)project for the region include both observations and modeling,as well as development of better and additional precipitation observations,all of which are topics for the next workshop.A well-designed RHP should lead to reductions in critical climate uncertainties in policy-relevant timeframes that can influence decisions on necessary investments in climate adaptation.

关键词： GEWEX Central Asia climate change agriculture

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