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Thermal noise-driven resonant sensors

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Microsystems & Nanoengineering 2024年第3期10卷 259-271页

作者： Yan Qiao Alaaeldin Elhady Mohamed Arabi Eihab Abdel-Rahman Wenming Zhang School of mechanical Engineering Shanghai Jiao Tong UniversityShanghaiChina department of systems Design Engineering University of WaterlooWaterlooONCanada

MEMS/NEMS resonant sensors hold promise for minute mass and force ***,one major challenge is that conventional externally driven sensors inevitably encounter undesired intrinsic noise,which imposes a fundamental limitation upon their signal-to-noise ratio(SNR)and,consequently,the ***,this restriction becomes increasingly pronounced as sensors shrink to the *** this work,we propose a counterintuitive paradigm shift that turns intrinsic thermal noise from an impediment to a constituent of the sensor by harvesting it as the driving force,obviating the need for external actuation and realizing‘noise-driven’*** sensors employ the dynamically amplified response to thermal noise at resonances for stimulus *** demonstrate that lightly damped and highly compliant nano-structures with high aspect ratios are promising candidates for this class of *** overcome the phase incoherence of the drive force,three noise-enabled quantitative sensing mechanisms are *** validated our sensor paradigm by experimental demonstrating noise-driven pressure and temperature ***-driven sensors offer a new opportunity for delivering practical NEMS sensors that can function at room temperature and under ambient pressure,and a development that suggests a path to cheaper,simpler,and low-power-consumption sensors.

关键词： noise resonant overcome

The viscous strip approach to simplify the calculation of the surface acoustic wave generated streaming

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 711-724页

作者： F.JAZINI DORCHEH M.GHASSEMI Fuel Cells and Nano systems(FCNS)Laboratory Department of Mechanical EngineeringK.N.Toosi University of TechnologyTehran 19697Iran

In recent decades,the importance of surface acoustic waves,as a biocompatible tool to integrate with microfluidics,has been proven in various medical and biological *** numerical modeling of acoustic streaming caused by surface acoustic waves in microchannels requires the effect of viscosity to be considered in the equations which complicates the *** this paper,it is shown that the major contribution of viscosity and the horizontal component of actuation is concentrated in a narrow region alongside the actuation *** the inviscid equations are considerably easier to solve,a division into the viscous and inviscid domains would alleviate the computational load *** particles'traces calculated by this approximation are excellently alongside their counterparts from the completely viscous *** is also shown that the optimum thickness for the viscous strip is about 9-fold the acoustic boundary layer thickness for various flow patterns and amplitudes of actuation.

关键词： surface acoustic wave microfluidics numerical simulation particle tracing acoustic streaming

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

Excitation of the abdominal ganglion affects the electrophysiological activity of indirect flight muscles of the honeybee Apis mellifera

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Insect Science 2024年第4期31卷 1187-1199页

作者： Haojia Ding Shaoze Yan State Key Laboratory of Tribology in Advanced Equipment(SKLT) Division of Intelligent and Biomechanical SystemsDepartment of Mechanical EngineeringTsinghua UniversityBeijingChina

Our understanding of the nervous tissues that affect the wing flapping of insects mainly focuses on the brain,but wing flapping is a rhythmic movement related to the central pattern generator in the ventral nerve *** verify whether the neural activity of the abdominal ganglion of the honeybee(Apis mellifera)affects the flapping-wing flight,we profiled the response characteristics of indirect flight muscles to abdominal ganglion ***,a change in the neural activity of ganglion 3 or ganglion 4 has a stronger effect on the electrophysiological activity of indirect flight muscles than that of ganglion *** electrophysiological activity of vertical indirect flight muscles is affected more by the change in neural activity of the abdominal ganglion than that of lateral indirect flight ***,the change in neural activity of the abdominal ganglion mainly causes the change in the muscular activity of indirect wing muscles,but the activity patterns change relatively little and there is little change in the complicated *** work improves our understanding of the neuroregulatory mechanisms associated with the flapping-wing flight of honeybees.

关键词： abdominal ganglion electromyography flapping wing honeybee indirect flight muscle muscular activity

Experimental Study on Heat Storage Properties Comparison of Paraffin/Metal Foams Phase Change Material Composites

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Journal of Thermal Science 2024年第2期33卷 469-478页

作者： Waqar AHMED Abid HUSSAIN Hanzla SHAHID Imran ALI Hafiz Muhammad ALI department of mechanical Engineering University of Engineering and TechnologyTaxila47080Pakistan department of mechanical Engineering Institute of Space TechnologyIslamabadPakistan department of mechanical Mechatronics and Manufacturing EngineeringUniversity of Engineering and Technology LahoreFaisalabad CampusPunjabPakistan mechanical Engineering department King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia Interdisciplinary Research Center for Renewable Energy and Power systems(IRC-REPS) King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia

Heat storage properties of phase change materials(PCMs) are essential characteristics that perform a key role in thermal heat energy storage *** thermal properties of PCMs can be improved by developing metal foam/PCM *** addition of metal foam in PCMs has a significant effect on the thermal characteristics of *** this paper,the heat storage properties of two different metal foam/PCM composites were experimentally *** behavior of paraffin in metal foam(copper and iron-nickel)/paraffin composites concerning pure paraffin at a constant heat flux of 1000 W/m^(2) in three directions simultaneously(x,y,and z) was *** was infiltrated into copper and iron-nickel foams to develop composite materials which resulted in enhancing the thermal conductivity of the paraffin.A comparative analysis is made on the heat storage properties of paraffin in copper and iron-nickel foams/paraffin *** temperature distribution during the phase transition process is experimentally *** comparison indicates that temperature uniformity in copper foam/paraffin composite is better than in iron-nickel foam/paraffin composite and pure paraffin at the same heat *** results show that at heat flux of 1000 W/m^(2),the heat storage time for copper foam/paraffin composite is 20.63% of that of iron-nickel foam/paraffin composite.

关键词： heat storage capacity paraffin/metal foam composite temperature uniformity heat storage rate phase transition process

Analysis and Optimization of Operational and Pollutant Attributes of Diesel Engine with CNT-Infused Orange Peel Biodiesel-Diesel Blend Fuel

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Journal of Thermal Science 2024年第2期33卷 761-778页

作者： Ranjeet RAI R.R.SAHOO mechanical Engineering department GLA UniversityMathura281406India mechanical Engineering department IIT(BHU)Varanasi221005India

The current study is performed to find sustainable solutions for the future of transportation and environmental *** conventional methods and experimental design table(L16 Orthogonal Array)techniques have been employed to examine and optimize a diesel-powered engine's operational and pollutant *** L16 Orthogonal Array is obtained through Taguchi's experimental design approach using Minitab 16 *** experimental design incorporated three control variables,namely engine speed,fuel type,and engine load,each with four *** operational parameters,namely brake thermal efficiency(BTE)and brake specific fuel consumption(BSFC),as well as the emission characteristics,including hydrocarbon(HC),carbon monoxide(CO),nitrogen oxide(NO),and smoke emissions,were acquired using the L16 orthogonal array(OA) and subsequently *** utilization of methodologies such as signal-to-noise(S/N) ratio and grey analysis was employed to determine the optimal operational state of the engine to achieve maximum performance while minimizing *** engine's ideal state of operation,in terms of BTE and BSFC,was determined to be at 75% engine load,1000 r/min engine speed,and using 10^(-4)(in vol) carbon nanotube incorporated 20% orange peel biodiesel(OPB20CNT100) blended fuel(A3-B1-C4).The study indicated that engine load significantly influenced BTE and BSFC,with 84.05% and 87.79% contribution factors,*** 25% engine load,1000 r/min,and OPB20CNT100 fuel(A1-B1-C4) CO,smoke,NO,and HC emissions were the *** load affects emissions the *** BSFC increased 3.10% and NO emissions 1.77%.BTE,CO,smoke,and HC emissions decreased by 1.9%,12.29%,47.05%,and 47.22%,respectively,at optimal operating conditions concerning diesel *** study shows that Taguchi-Grey's experimental design optimizes diesel engine operational and pollutant *** outcomes revealed that orange peel biodiesel infused with CNT can replace diesel fuel in a

关键词： Taguchi-Grey method OPB20CNT100 transesterification S/N ratio GRG HC CO and NO

A CFD study on the hydrodynamic response of a small-scale ice floe induced by a passing ship

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Journal of Hydrodynamics 2024年第2期36卷 290-299页

作者： Zongyu Jiang Spyros Hirdaris Sasan Tavakoli Mikko Suominen Pentti Kujala Marine and Arctic Technology Department of Mechanical EngineeringAalto UniversityEspooFinland Global Ship systems Centre ABS Hellenic SM LLC.AthensGreece department of Infrastructure Engineering The University of MelbourneMelbourneAustralia

A Reynolds averaged Navier-Stokes(RANS)computational fluid dynamics(CFD)model is built to investigate the hydrodynamic response of a circular ice floe under the influence of a passing ship in calm *** ship,mirroring the KRISO Container Ship’s hull design,progresses near an ice floe whose diameter is 30%of the ship’s length and its thickness is 3 *** ship advances at a constant speed,which is handled by using the overset mesh *** study focuses on the ice floe’s motions and the hydrodynamic forces induced by three speeds and three transverse distances of the passing *** reveal that ship-generated wakes notably influence the ice floe’s motions,with a greater influence on sway than ***,the ship’s speed and proximity distinctly affect the ice floe’s motions.

关键词： Hydrodynamics ship-ice interactions ice floe Reynolds averaged Navier-Stokes(RANS)computational fluid dynamics(CFD)

Diminishing the Perception Bias in the Working Environment Using a Network Generation-Based Framework

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Tsinghua Science and Technology 2024年第3期29卷 671-683页

作者： Jun Qian Tongda Zhang Xiao Sun Yueting Chai department of Automation Tsinghua UniversityBeijing 100084China department of mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055Chinaand with Systems Optimization LaboratoryStanford UniversityPalo AltoCA 94305USA

Income inequality is widespread in human society and has important implications for human ***’s perception of the environment bridges income inequality and individual behavioral *** research suggests that social income inequality is usually biased,either overestimated or ***,such phenomena have not been fully explored with quantitive prove,especially in the working environment based on performance data of actual *** fact,the correct perception of people is the basis of a fair environment for their production ***,the perception bias may weaken the adaptability and competitiveness of a company in the *** paper first confirms the prevalence of individual perception bias of income inequality within the working environment based on actual production *** results show that people tend to underestimate income inequity around them,and this underestimation grows with the real unfairness of the working ***,this paper proposes a network generation-based framework with a three-layer structure to correct perception bias using a cooperative network reengineering *** the framework,a homophily-based generative network model is proposed as the key *** simulation results show that our proposed framework effectively reduces individuals’perception bias of income inequality.

关键词： income inequality perception bias Gini coefficient factory production cooperative networkreengineering homophily-based generative network model

Development of wet adhesion of honeybee arolium incorporated polygonal structure with three-phase composite interfaces

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Friction 2024年第2期12卷 215-230页

作者： Lulu LIANG Jieliang ZHAO Qun NIU Li YU Xiangbing WU Wenzhong WANG Shaoze YAN Zhenglei YU School of mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Division of Intelligent and Biomechanical systems State Key Laboratory of TribologyDepartment of Mechanical EngineeringTsinghua UniversityBeijing 100084China Key of Bionic Engineering Ministry of EducationJilin UniversityChangchun 130022China

Inspired by the dynamic wet adhesive systems in nature,various artificial adhesive surfaces have been developed but still face different ***,the theoretical mechanics of wet adhesives has never been sufficiently ***,we develop a novel adhesive mechanism for governing wet adhesion and investigate the biological models of honeybee arolium for reproducing the natural wet adhesive ***-nano structures of honeybee arolium and arolium-prints were observed by Cryogenic scanning electron microscopy(Cryo-SEM),and the air pockets were found in the contact interface ***,the adhesive models with a three-phase composite interface(including air pockets,liquid secretion,and hexagonal frames of arolium),were formed to analyze the wet adhesion of honeybee *** results of theoretical calculations and experiments indicated an enhanced adhesive mechanism of the honeybee by liquid self-sucking effects and air-embolism *** these effects,normal and shear adhesion can be adjusted by controlling the proportion of liquid secretion and air pockets in the contact ***,the air-embolism effects contribute to the optimal coupling of smaller normal adhesion with greater shear adhesion,which is beneficial for the high stride frequency of *** works can provide a fresh perspective on the development of bio-inspired wet adhesive surfaces.

关键词： honeybee arolium air pockets wet adhesion a three-phase interface self-sucking effects air-embolism effects