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Compression properties of cost-efficient porous expanded clay reinforced AA7075 syntactic foams fabricated by industrial-oriented die casting technology

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China Foundry 2024年第1期21卷 60-70页

作者： İsmail Cem Akgün Çağın Bolat Ali Gökşenli Faculty of Mechanical Engineering Istanbul Technical University34437İstanbulTurkey Faculty of Engineering Samsun University55420SamsunTurkey

In today’s manufacturing industries,hard competition between rival firms makes it compulsory for researchers to design lighter and cheaper machine components due to the megatrends of cost-effectiveness and anti-pollution.At this point,aluminum syntactic foams(ASFs)are new-generation engineering composites and come into the upfront as a problem-solver.Owing to their features like low density,sufficient elongation,and perfect energy absorption ability,these advanced foams have been considerably seductive for many industrial sectors nowadays.In this study,an industrial-oriented automatic die casting technology was used for the first time to manufacture the combination of AA7075/porous expanded clay(PEC).Micro evaluations(optical and FESEM)reveal that there is a homogenous particle distribution in the foam samples,and inspections are compatible with the other ASF studies.Additionally,T6 aging heat treatment was operated on one half of the produced foams to explore the probable impact of aging on the compressive responses.Attained results show that PEC particles can be an alternative to expensive hollow spheres used in the previous works.Besides,a favorable relationship is ascertained between the aging treatment and mechanical properties such as compression strength and plateau strength.

关键词： die casting porous materials metal matrix sytanctic foams expanded clay compressive deformation

Evaluation of slope stability through rock mass classification and kinematic analysis of some major slopes along nH-1A from Ramban to Banihal, north Western Himalayas

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 167-182页

作者： Amit Jaiswal A.k.Verma T.n.Singh Department of Civil and Environmental Engineering Indian Institute of Technology PatnaPatna801106India

The network of Himalayan roadways and highways connects some remote regions of valleys or hill slopes,which is vital for India’s socio-economic growth.Due to natural and artificial factors,frequency of slope instabilities along the networks has been increasing over last few decades.Assessment of stability of natural and artificial slopes due to construction of these connecting road networks is significant in safely executing these roads throughout the year.Several rock mass classification methods are generally used to assess the strength and deformability of rock mass.This study assesses slope stability along the nH-1A of Ramban district of north Western Himalayas.Various structurally and non-structurally controlled rock mass classification systems have been applied to assess the stability conditions of 14 slopes.For evaluating the stability of these slopes,kinematic analysis was performed along with geological strength index(GSI),rock mass rating(RMR),continuous slope mass rating(CoSMR),slope mass rating(SMR),and Q-slope in the present study.The SMR gives three slopes as completely unstable while CoSMR suggests four slopes as completely unstable.The stability of all slopes was also analyzed using a design chart under dynamic and static conditions by slope stability rating(SSR)for the factor of safety(FoS)of 1.2 and 1 respectively.Q-slope with probability of failure(PoF)1%gives two slopes as stable slopes.Stable slope angle has been determined based on the Q-slope safe angle equation and SSR design chart based on the FoS.The value ranges given by different empirical classifications were RMR(37-74),GSI(27.3-58.5),SMR(11-59),and CoSMR(3.39-74.56).Good relationship was found among RMR&SSR and RMR&GSI with correlation coefficient(R 2)value of 0.815 and 0.6866,respectively.Lastly,a comparative stability of all these slopes based on the above classification has been performed to identify the most critical slope along this road.

关键词： Rock mass classification kinematic analysis Slope stability Himalayan road Static and dynamic conditions

SARS-CoV-2 spike protein-ACE2 interaction increases carbohydrate sulfotransferases and reduces n-acetylgalactosamine-4-sulfatase by p38 MAPk

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Signal Transduction and Targeted Therapy 2024年第3期9卷 1174-1185页

作者： Sumit Bhattacharyya Joanne k.Tobacman Jesse Brown VA Medical Center and University of Illinois at Chicago ChicagoIL 60612USA

Immunostaining in lungs of patients who died with CovID-19 infection showed increased intensity and distribution of chondroitin sulfate and decline in n-acetylgalactostamine-4-sulfatase(Arylsulfatase B;ARSB).To explain these findings,human small airway epithelial cells were exposed to the SARS-CoV-2 spike protein receptor binding domain(SPRBD)and transcriptional mechanisms were investigated.Phospho-p38 MAPk and phospho-SMAD3 increased following exposure to the SPRBD,and their inhibition suppressed the promoter activation of the carbohydrate sulfotransferases CHST15 and CHST11,which contributed to chondroitin sulfate biosynthesis.Decline in ARSB was mediated by phospho-38 MAPk-induced n-terminal Rb phosphorylation and an associated increase in Rb-E2F1 binding and decline in E2F1 binding to the ARSB promoter.The increases in chondroitin sulfotransferases were inhibited when treated with phospho-p38-MAPk inhibitors,SMAD3(SIS3)inhibitors,as well as antihistamine desloratadine and antibiotic monensin.In the mouse model of carrageenan-induced systemic inflammation,increases in phosphop38 MAPk and expression of CHST15 and CHST11 and declines in DnA-E2F binding and ARSB expression occurred in the lung,similar to theobserved effects in this SPRBD model of COVID-19 infection.Since accumulation of chondroitin sulfates is associated with fibrotic lung conditions and diffuse alveolar damage,increased attention to p38-MAPk inhibition may be beneficial in amelioratingCovid-19infections.

关键词： ACE2 lung inhibited

Methodological considerations of priming repetitive transcranial magnetic stimulation protocols in clinical populations

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General Psychiatry 2024年第1期37卷 173-176页

作者： Jack Jiaqi Zhang Zhongfei Bai kenneth n k Fong Department of Rehabilitation Sciences The Hong Kong Polytechnic UniversityHong KongChina Shanghai YangZhi Rehabilitation Hospital(Shanghai Sunshine Rehabilitation Centre) School of MedicineTongji UniversityShanghaiChina

InTRODUCTIOn Repetitive transcranial magnetic stimulation(rTMS)is a neuroplasticity-enhancing technique that modifies brain responsiveness to various therapeutic modalities in clinical psychiatric and neurological applications. Furthermore,its effect can be attributed to long-term potentiation(LTP)or longterm depression(LTD)-like neuroplasticity.However,responsiveness to rTMS is largely variable in healthy and pathological brains and is mediated by complex biological mechanisms.Metaplasticity refers to a higher-order plasticity mechanism in which the direction and magnitude of synaptic plasticity are modified by prior neuronal activity and is believed to be a significant factor leading to the response variability of rTMs.

关键词： stimulation clinical transcranial

Stability Analysis of DC Microgrid Clusters Based on Step-by-step System Matrix Building Algorithm

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 900-912页

作者： k.Jithin n.Mayadevi R.Hari kumar V.P.Mini IEEE the Department of Electrical Engineering College of Engineering Trivandrum APJ Abdul Kalam Technological University (APJAKTU) Senior Member

DC microgrids(DCMGs) are made up of a network of sources and loads that are connected by a number of power electronic converters(PECs). The increase in the number of these PECs instigates major concerns in system stability. While interconnecting the microgrids to form a cluster, the system stability must be ensured. This paper proposes a novel stepby-step system matrix building(SMB) algorithm to update the system matrix of an existing DCMG cluster when a new microgrid is added to the cluster through a distribution line. The stability of the individual DCMGs and the DCMG cluster is analyzed using the eigenvalue method. Further, the particle swarm optimization(PSO) algorithm is used to retune the controller gains if the newly formed cluster is not stable. The simulation of the DCMG cluster is carried out in MATLAB/Simulink environment to test the proposed algorithm. The results are also validated using the OP4510 real-time simulator(RTS).

关键词： Power system stability Stability criteria Microgrids Transfer functions Clustering algorithms Voltage control Eigenvalues and eigenfunctions

Detailed seismic zoning of the East kazakhstan region in the Republic of kazakhstan

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Geodesy and Geodynamics 2024年第2期15卷 156-165页

作者： natalya V.Silacheva n.P.Stepanenko O.k.kurilova A.D.kudabayeva A.T.Danabayeva Institute of Seismology Ministry of Emergency SituationsAlmaty 050060Kazakhstan

kazakhstan is currently drafting new construction regulations that comply with the major provisions of the Eurocodes.Such regulations are created on the basis of seismic zoning maps of various degrees of detail,developed by our Institute of Seismology using a new methodological approach for kazakhstan.The article is about creating the first normative map of the Detailed Seismic Zoning on a probabilistic foundation for the Republic of kazakhstan’s East kazakhstan region.We carried out the probabilistic assessment of seismic hazard using a methodology consistent with the main provisions of Eurocode 8and updated compared with that used in developing maps of kazakhstan’s General Seismic Zoning and seismic microzoning of Almaty.The most thorough and current data accessible for the area under consideration were combined with contemporary analytical techniques.Updates have been done to not only the databases being used but also the way seismic sources were shown,including active faults now.On a scale of 1:1000000,precise seismic zoning maps of the East kazakhstan region were created for two probabilities of exceedance:10%and 2%in 50 years in terms of peak ground accelerations and macroseismic intensities.The obtained seismic hazard distribution is generally consistent with the General Seismic Zoning of kazakhstan’s previous findings.However,because active faults were included and a thoroughly revised catalog was used,there are more pronounced zones of increased danger along the fault in the western part of the region.In the west of the territory,acceleration values also increased due to a more accurate consideration of seismotectonic conditions.Zoning maps are the basis for developing new state building regulations of the Republic of kazakhstan.

关键词： Probabilistic seismic hazard assessment Detailed seismic zoning Peak ground acceleration Microseismical intensity

Empirical model for fusion cross sections of Ca-induced reactions

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Chinese Physics C 2024年第3期48卷 126-132页

作者： Reddi Rani.L n.Sowmya k.n Sridhar H C.Manjunatha M.M.Armstrong Arasu Department of Physics St.Joseph's College(Autonomous)Affiliated to Bharathidasan UniversityTiruchirappalli620002TNIndia Department of Physics Govt.First.Grade CollegeChikkaballapur-562101KarnatakaIndia Department of Physics Govt.First.Grade CollegeMalur-563160KarnatakaIndia Department of Physics Govt.First.Grade CollegeDevanahalli-562110KarnatakaIndia

A new empirical formula for the astrophysical S-factor has been suggested as a function of the Coulomb interaction parameter,center of mass energy,and barrier height.About 22 fusion reactions with ^(40,48)Ca as projectiles were considered for different targets,leading to compound nuclei with atomic and mass numbers varying between 40≤Z≤≤Z≤112 and 88≤A≤27888≤A≤278,respectively.The fusion cross-sections have been estimated using the geometric factor,the Gamow-Sommerfield factor,and the empirical formula for the S-factor.This study's findings showed better agreement with those of available experiments when compared to Wong's formula.The present work leads to a smaller standard deviation value than Wong's formula when used to correlate the experimental data of calcium-induced fusion reactions.Wong's formula provides a good approximation of fusion cross-sections when the center of mass energy is below the fusion barrier when compared to above the fusion barrier.

关键词： fusion cross-sections Wong formula Gamow-Sommerfield-factor Geometric-factor S-factor

Optimum Profiles of Endwall Contouring for Enhanced net Heat Flux Reduction and Aerodynamic Performance

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Journal of Harbin Institute of Technology(new Series) 2024年第2期31卷 80-92页

作者： Arjun k S Tide P S Biju n Division of Mechanical Engineering School of EngineeringCochin University of Science&TechnologyKalamassery 682022India

Successfully utilized non-axisymmetric endwalls to enhance turbine efficiencies(aerodynamic and turbine inlet temperatures)by controlling the characteristics of the secondary flow in a blade passage.This is accomplished by steady-state numerical hydrodynamics and deep knowledge of the field of flow.Because of the interaction between mainstream and purge flow contributing supplementary losses in the stage,non-axisymmetric endwalls are highly susceptible to the inception of purge flow exit compared to the flat and any advantage rapidly vanishes.The conclusions reveal that the supreme endwall pattern could yield a lowering of the gross pressure loss at the design stage and is related to the size of the top-loss location being productively lowered.This has led to diminished global thermal exchange lowered in the passage of the vane alone.The reverse flow adjacent to the suction side corner of the endwall is migrated farther from the vane surface,as the deviated pressure spread on the endwall accelerates the flow and progresses the reverse flow core still downstream.The depleted association between the tornado-like vortex and the corner vortex adjacent to the suction side corner of the endwall is the dominant mechanism of control in the contoured end wall.In this publication,we show that the non-axisymmetric endwall contouring by selective numerical shape change method at most prominent locations is advantageous in lowering the thermal load in turbines to augment the net heat flux reduction as well as the aerodynamic performance using multi-objective optimization.

关键词： endwall contouring turbine vane heat transfer phantom cooling coolant injection net heat flux reduction aerodynamic performance

numerical Analysis of the Magnetic Dipole Effect on a Radiative Ferromagnetic Liquid Flowing over a Porous Stretched Sheet

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Fluid Dynamics & Materials Processing 2024年第2期20卷 293-310页

作者： G.Dharmaiah F.Mebarek-Oudina k.S.Balamurugan n.Vedavathi Department of Mathematics Narasaraopeta Engineering CollegeNarasaraopetIndia Department of Physics Faculty of SciencesUniversity of 20 Août 1955-SkikdaSkikdaAlgeria Department of Mathematics RVR&JC College of EngineeringGunturIndia Department of Mathematics Koneru Lakshmaiah Education FoundationVaddeswaramIndia

The effects of a magnetic dipole on a nonlinear thermally radiative ferromagnetic liquidﬂowing over a stretched surface in the presence of Brownian motion and thermophoresis are investigated.By means of a similarity transformation,ordinary differential equations are derived and solved afterwards using a numerical(the BVP4C)method.The impact of various parameters,namely the velocity,temperature,concentration,is presented graphically.It is shown that the nanoparticles properties,in conjunction with the magnetic dipole effect,can increase the thermal conductivity of the engineered nanoﬂuid and,consequently,the heat transfer.Comparison with earlier studies indicates high accuracy and effectiveness of the numerical approach.An increase in the Brow-nian motion parameter and thermophoresis parameter enhances the concentration and the related boundary layer.The skin-friction rises when the viscosity parameter is increased.A larger value of the ferromagnetic para-meter results in a higher skin-friction and,vice versa,in a smaller nusselt number.

关键词： Brownian motion thermo-phoresis radiation magnetic dipole BVP4C non-linear