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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

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

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

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Jumping droplets

Droplet 2024年第2期3卷 3-33页

作者： Jonathan B.Boreyko Department of Mechanical Engineering Virginia TechBlacksburgVirginiaUSA

When microdroplets with quasi-spherical contact angles coalesce together on a low-adhesion substrate,the capillary-inertial expansion of the liquid bridge induces a dramatic out-of-plane jumping event due to symmetry *** the onset of merging,droplet jumping initiates after a capillary-inertial time scale of tci∼1–100μs with characteristic jumping speeds of order vj∼0.1m/*** coalescenceinduced jumping-droplet effect is most commonly observed among a population of growing dew droplets on a superhydrophobic condenser,but can also occur by colliding deposited droplets together or during droplet sliding on fog *** this review,we cover the historical development of capillary-inertial jumping droplets,summarize the decade-long effort to rationalize the ultra-low energy conversion efficiency and critical droplet size of the phenomenon,and then present 15 variations on a theme of ***-inertial jumping droplets are not only a visceral illustration of the surprising power of surface tension at the microscale but they also have the potential to enhance phase-change heat transfer,enable selfcleaning surfaces,combat frost formation,harvest energy,and govern the rate of disease spread for wheat crops.

关键词： capillary illustration rational

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

Understanding the initial use stage of cement mortar lining in drinking water distribution systems:Silicon and aluminum as stability indicators

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Journal of Environmental Sciences 2024年第1期135卷 495-505页

作者： Qiaozhi Liu Yuan Zhuang Guiwei Li Yao Zhang Marc A.Edwards Baoyou Shi Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Civil and Environmental Engineering Virginia TechBlacksburgVA 24061USA

The cement mortar lining(CML)of commonly used ductile iron pipes can severely deteriorate the drinking water quality at the initial stage of use,but the behavioral characteristics of different elements release from the CML in this stage is still *** this study,dynamic immersion experiments with new cement mortar lined ductile iron pipe reactors were conducted under different feed water hardness and alkalinity *** results showed that the release of alkaline substances from the CML at the initial stage of use could strongly influence the pH of water,which consequently greatly impacted the release/precipitation behaviors of calcium,aluminum and *** pH and aluminum concentration of the effluent water could reach 11.5 and 700μg/L within 24 hr of hydraulic retention time,respectively,under conditions of relatively lower hardness and *** to the pH elevation,calcium carbonate precipitation could occur even at much lower feed water *** the aluminum and silicon could keep release from the CML in soluble form at different hardness and alkalinity levels,and their release rate depended on the amount of calcium carbonate ***,aluminum and silicon were more suitable as indicators of the corrosion intensity at the initial stage of CML use rather than the traditional calcium carbonate precipitation *** feed water hardness and alkalinity levels for mitigating the initial intense corrosion of CML were proposed:hardness>40 mg/L(CaCO_(3)),alkalinity>100 mg/L(CaCO_(3)).

关键词： Cement mortar lining Hardness Alkalinity Elemental release Drinking water supply

Guest editorial:Special Issue on Artificial Intelligence and Emerging Computational Approaches for Tribology

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Friction 2024年第6期12卷 1057-1059页

作者： Zhinan ZHANG Shuaihang PAN Bart RAEYMAEKERS State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Department of Mechanical Engineering University of UtahSalt Lake CityUT 84112USA Department of Mechanical Engineering Virginia TechBlacksburgVA 24061USA

Tribo-behavior is a complex system-based time-dependent process,and it is difficult to accurately model a tribo-system and predict its ***,tribology research,in most cases,has relied on extensive *** by the artificial intelligence(AI)-for-science revolution,AI and other emerging computational approaches provide opportunities to explore the complex processes in tribo-systems and the physical mechanisms of tribo-behavior in an efficient way,significantly pushing the boundaries of tribology research.

关键词： behavior editorial artificial

Review on Lithium-ion Battery PHM from the Perspective of Key PHM Steps

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Chinese Journal of Mechanical Engineering 2024年第4期37卷 1-22页

作者： Jinzhen Kong Jie Liu Jingzhe Zhu Xi Zhang Kwok-Leung Tsui Zhike Peng Dong Wang School of Mechanical Engineering Hebei University of TechnologyTianjin 300401China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Grado Department of Industrial and Systems Engineering Virginia Polytechnic Institute and State UniversityBlacksburg 24061USA School of Mechanical Engineering Ningxia UniversityNingxia 750021China

Prognostics and health management(PHM)has gotten considerable attention in the background of Industry *** PHM contributes to the reliable and safe operation of electric ***,relevant reviews are still continuously updated over *** this paper,we browsed extensive literature related to battery PHM from 2018to 2023 and summarized advances in battery PHM field,including battery testing and public datasets,fault diagnosis and prediction methods,health status estimation and health management *** last topic includes state of health estimation methods,remaining useful life prediction methods and predictive maintenance *** of these categories is introduced and discussed in *** on this survey,we accordingly discuss challenges left to battery PHM,and provide future research *** research systematically reviews recent research about battery PHM from the perspective of key PHM steps and provide some valuable prospects for researchers and practitioners.

关键词： Lithium-ion batteries Prognostics and health management Remaining useful life State of health Predictive maintenance

Direct 4D printing of functionally graded hydrogel networks for biodegradable,untethered,and multimorphic soft robots

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International Journal of Extreme Manufacturing 2024年第2期6卷 407-416页

作者： Soo Young Cho Dong Hae Ho Sae Byeok Jo Jeong Ho Cho Department of Chemical and Biomolecular Engineering Yonsei UniversitySeoul 03722Republic of Korea Department of Mechanical Engineering Virginia TechBlacksburgVA 24061United States of America School of Chemical Engineering Sungkyunkwan UniversitySuwon 16419Republic of Korea SKKU Institute of Energy Science and Technology(SIEST) Sungkyunkwan UniversitySuwon 16419Republic of Korea

Recent advances in functionally graded additive manufacturing(FGAM)technology have enabled the seamless hybridization of multiple functionalities in a single *** robotics can become one of the largest beneficiaries of these advances,through the design of a facile four-dimensional(4D)FGAM process that can grant an intelligent stimuli-responsive mechanical functionality to the printed ***,we present a simple binder jetting approach for the 4D printing of functionally graded porous multi-materials(FGMM)by introducing rationally designed graded multiphase feeder *** graded cross-linking agents gradually form stable porous network structures within aqueous polymer particles,enabling programmable hygroscopic deformation without complex mechanical ***,a systematic bed design incorporating additional functional agents enables a multi-stimuli-responsive and untethered soft robot with stark stimulus *** biodegradability of the proposed 4D-printed soft robot further ensures the sustainability of our approach,with immediate degradation rates of 96.6%within 72 *** proposed 4D printing concept for FGMMs can create new opportunities for intelligent and sustainable additive manufacturing in soft robotics.

关键词： intelligent and sustainable additive manufacturing multi-material four-dimensional printing untethered soft robot multi-stimuli-responsive soft robot biodegradable soft robotics

Automated,economical,and environmentally-friendly asphalt mix design based on machine learning and multi-objective grey wolf optimization

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第3期11卷 381-405页

作者： Jian Liu Fangyu Liu Linbing Wang Department of Civil and Environmental Engineering Virginia Polytechnic Institute and State UniversityBlacksburgVA 24061USA School of Environmental CivilAgricultural and Mechanical EngineeringUniversity of GeorgiaAthensGA 30602USA Illinois Center for Transportation Department of Civil and Environmental EngineeringUniversity of Illinois Urbana-ChampaignUrbanaIL 61801USA

The increasing impact of the greenhouse effect on ecosystems is prompting transportation agencies to seek methods for reducing CO_(2)emissions during pavement construction and ***,the laboratory mix design process,which involves selecting aggregate gradation and binder content,is time-consuming and *** accelerate the traditional mix design procedure,this study presented a mix design procedure that can automatically determine gradation and binder content based on machine learning(ML)and a meta-heuristic ***,ML approaches were employed to model the relationship between volumetric properties(mixture bulk specific gravity(Gmb)and air void(VV))and both mixture component properties and mixture proportion,based on a dataset collected from literature with 660 mixture *** with the prediction of ML models and the modified multi-objective grey wolf optimization(MOGWO)algorithm,an automatic asphalt mix design was proposed to pursue three goals,including VV,cost,and CO_(2)*** results indicated that least squares support vector regression(LSSVR)and e Xtreme gradient boosting(XGBoost)achieved the highest prediction accuracies(correlation coefficient:0.92 for VV and 0.96 for Gmb).The MOGWO algorithm successfully found the 26 optimal mix designs for the case of VV *** ***_(2)*** to the traditional laboratory design,the optimal mixture with VV of4%achieves a cost saving of 2.46%and a reduction of 4.03%in carbon *** volumetric properties of the mixtures output by the approach also align closely with values measured in a laboratory.

关键词： Asphalt mix design Machine learning MOGWO CO_(2)emission Volumetric properties