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Liquid surface depression and bubble generation by acoustic radiation

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Droplet 2024年第3期3卷 65-70页

作者： Zilong Fang Kai-Tak Wan Mohammad E.Taslim mechanical and industrial engineering Department Northeastern UniversityBostonMassachusettsUSA

Liquid surfaces can be depressed by applying acoustic radiation force. The balancebetween the acoustic radiation force, surface tension force, and buoyantforce sustainsthe stable dimple depression. Beyond a certain threshold, higher acoustic radiationforce leads to instability and bubble formation. The bubble size is determined by theacoustic radiation force and the liquid surface tension. Effective management of bubble generation can be achieved by controlling acoustic radiation *** methodfor creating depression on liquid surfaces and generating bubbles is described, whichrequires neither gas supply nor direct contact with equipment.

关键词： force. bubble generating

Numerical analysis of the return flow solar air heater(RF-SAH)with assimilation of V-type artificial roughness

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Energy and Built Environment 2024年第2期5卷 185-193页

作者： Prashant Raturi Hemlata Deolal Sanjeev Kimothi Department of mechanical engineering Swami Rama Himalayan University Dehradun248140India Department of mechanical engineering DIT UniversityDehradun248001India Division of Research&Innovation Dept.of PhysicsUttaranchal University248007India

A novel design of Return Flow Solar Air Heater(RFSAH)with different arrangements of baffles especially V-Type Artificial roughness is simulated and numerically analyzed with energy balance *** enhance the effectiveness of baffles,numerous studies have been *** performance of the RFSAH is studied in terms of thermal efficiency,thermo-hydraulic efficiency,and optimization of baffle *** Thermal efficiency and thermo-hydraulic efficiency are found in RFSAH with baffle on both sides of the absorber plate and mass flow rate above 0.2kg/*** analysis of the influencing parameters is carried out and reported the best performance of the system on selective geometrical parameters(ψ=0.7,β=20%,e/H=1,p/e=0.8,α=60°).The results obtained from the present model are validated with the published experimental results and have been found in quite reasonable agreement with an average error of 16.45%.Thermal and Thermohydraulic efficiency of RFSAH with a baffle on both sides of the absorber plate is maximum among baffles below,above,and on both sides of the absorber *** is observed that the thermal efficiency of RFSAH is greater than *** proposed optimum baffles roughness is suggested to increase the air upholding time period for more efficient output.

关键词： Numerical analysis Energy Balance Equations Thermal Efficiency Return flow solar air heater V-baffles

Modelling rapid non-destructive test using light weight deflectometer on granular soils across different degrees of saturation

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Journal of Rock Mechanics and Geotechnical engineering 2024年第7期16卷 2732-2748页

作者： Javad Ghorbani Arooran Sounthararajah Troyee Tanu Dutta Jayantha Kodikara ARC Smart Pavements Hub Dept.of Civil EngineeringMonash UniversityVIC3800Australia

This study introduces an advanced finite element model for the light weight deflectometer(LWD),which integrates contact mechanics with fully coupled *** simulating LWD tests on granular soils at various saturation levels,the model accurately reflects the dependence of the LWD modulus on dry density,water content,and effective *** model addresses and overcomes the limitations of previous finite element models for this specific ***,this research presents the first experimentally validated fully coupled contact impact ***,the research provides a comparative assessment of elastoplastic and nonlinear elastic models and contrasts an enriched node-tosegment method(developed in this study)with the more precise mortar technique for contact *** comparisons reveal unique advantages and challenges for each ***,the study underscores the importance of careful application of the LWD modulus,emphasising the need for sophisticated tools to interpret soil behaviour accurately.

关键词： Granular soils Plasticity Finite element analysis Contact mechanics Modulus Degree of saturation

Broadband angular spectrum analog processors based on all-dielectric metasurfaces

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 188-190页

作者： Lin Deng Yongmin Liu Department of Electrical and Computer engineering Northeastern UniversityBoston 02115USA Department of mechanical and industrial engineering Northeastern UniversityBoston 02115USA

Digital signal processors are extensively used to execute mathematical operations and advanced computational tasks on digital ***,they suffer from several inherent limitations,including low speed,high energy consumption,and large memory requirements,because of the hardware bottleneck and the imperative conversion between digital and analogue signals.

关键词： dielectric spectrum hardware

Breakdown of effective medium theory:A study of photonic spin Hall effect in deep-subwavelength all-dielectric multilayers

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 173-174页

作者： Yongmin Liu Department of mechanical and industrial engineering Northeastern UniversityBoston 02115USA Department of Electrical and Computer engineering Northeastern UniversityBoston 02115USA

Effective medium theory(EMT)has been widely applied in material science,electromagnetics and photonics to determine the effective material properties for inhomogeneous composites comprising subwavelength *** versatility of this foundational approach has been established through its application in classical Maxwell-Garnet models,which encompass relatively simple structures。

关键词： composites theory dielectric

Cryogenic and conventional milling of AZ91 magnesium alloy

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Journal of Magnesium and Alloys 2024年第6期12卷 2503-2519页

作者： Vikas Marakini Srinivasa Pai P Gururaj Bolar Bhaskara P Achar Department of mechanical engineering Nitte(Deemed to be University)NMAM Institute of Technology(NMAMIT)Nitte 574110India Department of mechanical and industrial engineering Manipal Institute of TechnologyManipal Academy of Higher EducationManipal 576104India

Use of magnesium is the need of the hour due to its low density as well as its high strength-to-weight and stiffness-to-weight ratio *** study focuses on the effectiveness of liquid nitrogen(LN_(2))assisted cryogenic machining on the surface integrity(SI)characteristics of AZ91 magnesium *** milling using uncoated carbide inserts have been performed under liquid nitrogen(LN_(2))assisted cryogenic condition and compared with conventional(dry)*** are performed using machining parameters in terms of cutting speeds of 325,475,625 m/min,feed rates of 0.05,0.1,0.15 mm/teeth and depth of cuts of 0.5,1,1.5 mm *** significant surface integrity characteristics such as surface roughness,microhardness,microstructure,and residual stresses have been *** of SI characteristics with respect to milling parameters have been identified using statistical technique such as ANOVA and signal-to-noise(S/N)ratio ***,the multi criteria decision making(MCDM)techniques such as additive ratio assessment method(ARAS)and complex proportional assessment(COPRAS)have been utilized to identify the optimal conditions for milling AZ91 magnesium alloy under both dry and cryogenic *** of LN_(2)during machining,resulted in reduction in machining temperature by upto 29%with a temperature drop from 251.2℃under dry condition to 178.5℃in cryogenic *** showed the advantage of performing cryogenic milling in improving the surface integrity to a significant *** machining considerably minimized the roughness by upto 28%and maximised the microhardness by upto 23%,when compared to dry *** speed has caused significant impact on surface roughness(95.33%-dry,92.92%-cryogenic)and surface microhardness(80.33%-dry,82.15%-cryogenic).Due to the reduction in machining temperature,cryogenic condition resulted in compressive residual stresses(maximumσ║=-113 MPa)on the alloy *** indicate no

关键词： Magnesium alloy Cryogenic machining Roughness Microhardness Microstructure Residual stress Multi criteria decision making

Generating synthetic as-built additive manufacturing surface topography using progressive growing generative adversarial networks

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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

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

An integrated framework for assessing renewable-energy supply chains using multicriteria decision-making:a study on Bangladesh

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Clean Energy 2024年第3期8卷 1-19页

作者： A.M.Almas Shahriyar Azad Zarin Tasnim Oishi Md.Ariful Haque Pronob Das Sabbir Ahmed Udoy Khaled Mohammad Shifullah Bhuiya Department of industrial&Production engineering Rajshahi University of Engineering&TechnologyRajshahi-6204Bangladesh Department of mechanical engineering Rajshahi University of Engineering&TechnologyRajshahi-6204Bangladesh

The depletion in non-renewable energy sources and a fast-growing population in Bangladesh are exacerbating the already existing energy scarcity,highlighting the need for an efficient and robust renewable-energy supply *** primary goal of this study is to evaluate the most optimized renewable-energy supply chain based on natural resource availability and government policies of *** the present study,four renewable energy resources,including solar,biomass,wind and hydropower,are studied and nine subcriteria are defined under four primary criteria for each supply *** for Order Preference by Similarity to Ideal Solution(TOPSIS)and VIseKriterijumska Optimizacija I Kompromisno Resenje(VIKOR)are multicriteria decision-making approaches used in this study to compare and choose the best renewable-energy supply *** relative significance of four supply-chain criteria for primary renewable energy in this study,namely energy procurement,production,operations and maintenance costs,and social and environmental impact,is gathered via a *** results of this research,supported by a comprehensive sensitivity analysis,indicate that hydropower is the best renewable-energy supply chain,followed by wind as a compromise solution,biomass and *** study also demonstrates that no energy source can satisfy all supply-chain criteria alone;each resource is better for a specific criterion-solar is better for procurement,hydropower is significant for production and wind is remarkable for operations and social ***,to maximize output,renewable energy sources must be *** Bangladesh’s perspective,for the first time,by using TOPSIS and VIKOR together,this study offers significant insights to establish an efficient and sustainable renewable-energy supply chain for practitioners,academics and policymakers.

关键词： renewable-energy supply chain Bangladesh multicriteria decision-making TOPSIS(Technique for Order Preference by Similarity to Ideal Solution) VIKOR(VIseKriterijumska Optimizacija I Kompromisno Resenje)