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free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 543-562页

作者： h.m.fEIZABAD m.h.YAS Department of mechanical Engineering Razi UniversityKermanshah ***Iran

Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent years.Bamboo fibers are renowned for their good mechanical properties,abundance,and short cycle growth.As beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BfRC)beams on the elastic foundation.Three different functionally graded(fG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the thickness.The elastic properties of the composite are determined with the law of mixture.Employing hamilton’s principle,the governing equations of motion are obtained.The generalized differential quadrature method(GDQm)is then applied to the equations to obtain the results.The achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam change.furthermore,a comparative study is conducted between the derived analysis outcomes for BfRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the fG-◇fiber distribution.Eventually,the obtained analysis results of BfRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BfRC beams are lower than those of CNTRC beams.

关键词： bamboo fiber free vibration buckling analysis functionally graded(fG)beam elastic foundation generalized differential quadrature method(GDQm)

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fast efficient photon deceleration in plasmas by using two laser pulses at different frequencies

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matter and Radiation at Extremes 2024年第3期9卷 11-18页

作者： Y.X.Wang X.L.Zhu S.m.Weng P.Li X.f.Li h.Ai h.R.Pan Z.m.Sheng Key Laboratory for Laser Plasmas(moe) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of IfSA Shanghai Jiao Tong UniversityShanghai 200240China Research Center of Laser fusion of China Academy of Engineering Physics MianyangSichuan 621900China State key Laboratory of high field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Tsung-dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China

The generation of ultrashort high-power light sources in the mid-infrared(mid-IR)to terahertz(Thz)range is of interest for applications in a number of fields,from fundamental research to biology and medicine.Besides conventional laser technology,photon deceleration in plasma wakes provides an alternative approach to the generation of ultrashort mid-IR or Thz pulses.here,we present a photon deceleration scheme for the efficient generation of ultrashort mid-IR or Thz pulses by using an intense driver laser pulse with a relatively short wavelength and a signal laser pulse with a relatively long wavelength.The signal pulse trails the driver pulse with an appropriate time delay such that it sits at the front of the second wake bubble that is driven by the driver pulse.Owing to its relatively long wavelength,the signal pulse will be subjected to a large gradient of the refractive index in the plasma wake bubble.Consequently,the photon deceleration in the plasma wake becomes faster and more efficient for signal pulses with longer wavelengths.This greatly enhances the capacity and efficiency of photon deceleration in the generation of ultrashort high-power light sources in the long-wavelength IR and Thz spectral ranges.

关键词： laser ultrashort photon

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 applications.The 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 solution.In 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 boundary.Since the inviscid equations are considerably easier to solve,a division into the viscous and inviscid domains would alleviate the computational load significantly.The particles'traces calculated by this approximation are excellently alongside their counterparts from the completely viscous model.It 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

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Novel Sustainable Cellulose Acetate Based Biosensor for Glucose Detection

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Journal of Renewable materials 2024年第2期12卷 369-380页

作者： m.f.Elkady E.m.El-Sayed mahmoud Samy Omneya A.Koriem h.Shokry hassan Chemical and Petrochemical Engineering Department Egypt-Japan University of Science and TechnologyNew Borg El-ArabAlexandriaEgypt fabrication Technology Research Department Advanced Technology and New Materials Research InstituteCity of Scientific Research and Technological Applications(SRTA-City)New Borg El-ArabAlexandria21934Egypt Department of Public Works Engineering Faculty of EngineeringMansoura UniversityMansoura35516Egypt Environmental Engineering Department Egypt-Japan University of Science and TechnologyNew Borg El-ArabAlexandriaEgypt Electronic materials Research Department Advanced Technology and NewMaterials Research InstituteCity of Scientific Research and Technological Applications(SRTA-City)New Borg El-ArabAlexandria21934Egypt

In this study,green zinc oxide(ZnO)/polypyrrole(Ppy)/cellulose acetate(CA)film has been synthesized via solvent casting.This film was used as supporting material for glucose oxidase(GOx)to sensitize a glucose biosensor.ZnO nanoparticles have been prepared via the green route using olive leaves extract as a reductant.ZnO/Ppy nanocomposite has been synthesized by a simple in-situ chemical oxidative polymerization of pyrrole(Py)monomer using ferric chloride(feCl3)as an oxidizing agent.The produced materials and the composite films were characterized using X-ray diffraction analysis(XRD),scanning electron microscope(SEm),fourier transform infrared(fTIR)and thermogravimetric analysis(TGA).Glucose oxidase was successfully immobilized on the surface of the prepared film and then ZnO/Ppy/CA/GOx composite was sputtered with platinum electrode for the current determination at different initial concentrations of glucose.Current measurements proved the suitability and the high sensitivity of the constructed biosensor for the detection of glucose levels in different samples.The performance of the prepared biosensor has been assessed by measuring and comparing glucose concentrations up to 800 ppm.The results affirmed the reliability of the developed biosensor towards real samples which suggests the wide-scale application of the proposed biosensor.

关键词： Biosensors composite films glucose polypyrrole green ZnO cellulose acetate

A new technique for fault diagnosis in transformer insulating oil based on infrared spectroscopy measurements

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high Voltage 2024年第2期9卷 319-335页

作者： mohamed m.f.Darwish mohamed h.A.hassan Nagat m.K.Abdel-Gawad matti Lehtonen Diaa-Eldin A.mansour Department of Electrical Engineering Faculty of Engineering at ShoubraBenha UniversityCairoEgypt Department of Electrical Engineering and Automation School of Electrical EngineeringAalto UniversityEspooFinland Department of Electrical Power Engineering Egypt-Japan University of Science and Technology(E-JUST)New Borg El-Arab CityEgypt Department of Electrical Power and machines Engineering Faculty of EngineeringTanta UniversityTantaEgypt

Condition monitoring of the insulating system within power transformers has a massive importance according to the electrical utilities.Dissolved gas analysis(DGA)is frequently used for this purpose.however,DGA lacks the necessary level of accuracy to identify all equipment faults,particularly in their initial stages of degradation.Also,it does not have the capability for real-time monitoring and relies on manual sampling and laboratory testing,causing potential delays in fault identification.Additionally,the interpretation of DGA data necessitates specialised expertise,which may pose difficulties for smaller entities that have limited access to resources.Therefore,the contribution of this research is to use infrared spectroscopy measurements as a new effective technique substituting the DGA method for fault diagnosis in insulating oil.The inception faults that were considered in this study were the electrical fault(discharges of high energy)and the thermal fault(300°Cmperaturehat,two test cells were crafted especially for serving the simulation processes inside the laboratory for both types of inception faults.Subsequently,six samples of pure paraffinic mineral oil were taken to be degraded in the laboratory.following that,all of them besides another sample that were not subjected to any kind of faults were taken to be examined by fourier transform infrared(fTIR)spectroscopy to obtain an overview of the oil's behaviour in each fault case.After that,the fTIR analysis was initially verified utilising the DGA method.Then,for further affirmation,the dielectric dissipation factor(DDf)for all samples was measured.In the final analysis,the verification tests provide experimental evidence about the outperformance of this new optical technique in detecting the transformer's inception faults in addition to proving its potential for being a superior alternative to the well-known traditional diagnostic techniques.

关键词： fault diagnosis spectroscopy

Dysprosium oxide,alumina,and graphene oxide reinforced polycaprolactone thin films:Thermal stability,morphology,and cell viability

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Journal of Rare Earths 2024年第7期42卷 1337-1343页

作者： mohamed Tharwat Elabbasy mohamed R.Atteya mai A.Samak mousa Abdelrahman Tahani Almahmoud m.A.El-morsy A.A.menazea m.f.h.Abd El-Kader Department of Public health College of Public Health and Health InformaticsUniversity of Ha'il food Control Department Faculty of Veterinary MedicineZagazig University Department of Physical Therapy College of Applied Medical SciencesUniversity of Ha'il Department of histology and Cell Biology Faculty of MedicineZagazig University College of Nursing University of Ha'il College of Science and humanities in Al-Kharj Physics DepartmentPlasma Technology and Material Science UnitPrince Sattam Bin Abdulaziz University Physics Department Faculty of ScienceUniversity of Damietta Spectroscopy Department Physics Research InstituteNational Research Centre Biophysics Department Faculty of ScienceCairo University

Developing a biomaterial for wound healing applications is still a challenge.herein,dysprosium oxide（Dy2O3）,aluminum oxide（Al2O3）,and graphene oxide（GO） were embedded in cast films based on polycaprolactone（PCL） to be examined for wound dressing usage.Different techniques were used to characterize the fabricated films including X-ray diffraction（XRD）,fourier transform infrared spectroscopy（fTIR）,Raman,and scanning electron microscopy（SEm）,besides their biological activity.The thermogravimetric analysis（TGA） exhibits high thermal stability as the scaffold weight decreases slightly to 98.6% after raising the temperature from room temperature to 280℃.The cell viability was investigated and it is shown that the viable cells grow up to approximately 93% at 75 μg/mL.meanwhile,the cell attachment shows excellent behavior as the cells attach on most of the surface of the modified PCL which shows high biocompatibility.

关键词： Al2O3 Biocompatible Dy2O3 Polycaprolactone Rare earths Wound healing

microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with different prestrain levels

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Journal of materials Science & Technology 2024年第4期171卷 80-93页

作者： Y.h.Zhang h.Li Z.W.Yang X.Liu Q.f.Gu State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of high-Performance Precision forming Technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)shape memory alloy(SmA)is a promising material in the aerospace field due to its wide transformation hysteresis.The application of shape memory effect depends on multistep thermomechan-ical loading,viz.,low-temperature deformation and subsequent heating to recovery.Low-temperature deformation prestrain plays a pivotal role in shape memory properties tailoring of SmA components.however,microstructure evolution and deformation mechanisms of Ni_(47)Ti_(44)Nb_(9)SmA subjected to vari-ous prestrain levels are still unclear.To this end,microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with prestrain levels of 8%-16%at-28℃(m_(s)+30℃)were investigated.The results demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,respectively.In stageⅡ,the stress-induced martensitic transformation is accompanied by the dislocation slip of the NiTi matrix andβ-Nb inclusions.In stageⅢ,in addition to the higher density of dislocations and further growth of stress-induced martensite variants(SImVs),(001)compound twins are introduced as a result of the(001)deformation twinning in stress-induced martensite.more{20-1}martensite twins are gradually introduced in stageⅣ.Correspondingly,after subsequent unloading and heating,a higher density of{114}austenite twins form in the specimen with a larger prestrain of 16%.With increasing prestrain from 8%to 16%,the recoverable strainε_(re)^(T)upon heating increases first and then decreases.Theε_(re)^(T)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%prestrain.The increase ofε_(re)^(T)can be attributed to the formation of new SImVs,the further growth of existing SImVs,and the recoverable(001)compound twins.While the decrease ofε_(re)^(T)is mainly associated with the irrecoverable strain by{20−1}martensite twins.The effect ofβ-Nb inclusions on the evolution of SImVs i

关键词： Ni_(47)Ti_(44)Nb_(9)shape memory alloy Wide transformation hysteresis Thermomechanical loading microstructure evolution Shape memory behaviors Stress-induced martensitic transformation Deformation twinning

Connections Between Induction Generator Effect and Open-loop modal Proximity to Cause Sub-synchronous Oscillations in Series-compensated Power System

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 963-973页

作者： Wenjuan Du Yang Wang h.f.Wang Tao Zhao Tim Littler College of Electrical Engineering Sichuan UniversityChengduChina School of Electrical Engineering the Queen’s University of BelfastBelfastUK IEEE

The induction generator effect(IGE)and the openloop modal proximity(OLmP)are two different reasons why subsynchronous oscillations(SSOs)in a series-compensated power system(SCPS)may occur.The IGE attributes the growing SSOs to negative resistance,while the OLmP explains the SSO mechanism from the standpoint of modal conditions.In this paper,we investigate the connections between the IGE and the OLmP through equivalent RLC circuit and open-loop modal analysis.Our investigation is conducted for two types of seriescompensated power systems where either a synchronous generator or a DfIG is connected at the sending end.The investigation reveals the conditions,in which the IGE and the OLmP may jointly cause the growing SSOs,i.e.,both the IGE and the OLmP can explain why the growing SSOs occur.furthermore,the investigation indicates that the IGE and the OLmP may be totally irrelevant and lead to growing SSOs separately.This implies that it is possible that in a SCPS,the growing SSOs are only due to the IGE,and the OLmP is non-existent,and vice versa.hence,when the growing SSOs occurs in a SCPS,examination based on both the IGE and the OLmP should be carefully conducted in order to find if the oscillatory instability is due to the IGE,or the OLmP,or both of them.

关键词： Induction generator effect open-loop modal proximity series compensation sub-synchronous oscillations

A Comprehensive Review on Charging Topologies and Power Electronic Converter Solutions for Electric Vehicles

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Journal of modern Power Systems and Clean Energy 2024年第3期12卷 675-694页

作者： Abdelfatah Ali hossam h.h.mousa mostafa f.Shaaban maher A.Azzouz Ahmed S.A.Awad the Department of Electrical Engineering American University of Sharjah the Department of Electrical Engineering South Valley University the Department of Electrical and Computer Engineering University of Windsor Electrical Engineering Department Qatar University the Department of Electrical and Computer Engineering Sultan Qaboos University

Electric vehicles(EVs) are becoming more popular worldwide due to environmental concerns, fuel security, and price volatility. The performance of EVs relies on the energy stored in their batteries, which can be charged using either AC(slow) or DC(fast) chargers. Additionally, EVs can also be used as mobile power storage devices using vehicle-to-grid(V2G) technology. Power electronic converters(PECs) have a constructive role in EV applications, both in charging EVs and in V2G. hence, this paper comprehensively investigates the state of the art of EV charging topologies and PEC solutions for EV applications. It examines PECs from the point of view of their classifications, configurations, control approaches, and future research prospects and their impacts on power quality. These can be classified into various topologies: DC-DC converters, AC-DC converters, DC-AC converters, and AC-AC converters. To address the limitations of traditional DC-DC converters such as switching losses, size, and high-electromagnetic interference(EmI), resonant converters and multiport converters are being used in high-voltage EV applications. Additionally, power-train converters have been modified for high-efficiency and reliability in EV applications. This paper offers an overview of charging topologies, PECs, challenges with solutions, and future trends in the field of the EV charging station applications.

关键词： Topology DC-DC power converters Vehicle-to-grid Electric vehicle charging Batteries Transportation Electromagnetic interference