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Nonlinear dynamic modeling of planar moving Timoshenko beam considering non-rigid non-elastic axial effects

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 479-496页

作者： m.ABBASI GAVARI m.R.HOmAEINEZHAD Faculty of mechanical Engineering K.N.Toosi University of TechnologyTehran 19991-43344Iran

Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible *** manipulator consists of an elastic arm,a rotary motor,and a rigid carrier,and undergoes general in-plane rigid body motion along with elastic transverse *** accurately model the elastic behavior,Timoshenko’s beam theory is used to describe the flexible arm,which accounts for rotary inertia and shear deformation *** applying Newton’s second law,the nonlinear governing equations of motion for the manipulator are derived as a coupled system of ordinary differential equations(ODEs)and partial differential equations(pDEs).Then,the assumed mode method(Amm)is used to solve this nonlinear system of governing equations with appropriate shape *** assumed modes can be obtained after solving the characteristic equation of a Timoshenko beam with clamped boundary conditions at one end and an attached mass/inertia at the *** addition,the effect of the transverse vibration of the inextensible arm on its axial behavior is *** the axial rigidity,the effect makes the rigid body dynamics invalid for the axial behavior of the ***,numerical simulations are conducted to evaluate the performance of the developed model,and the results are compared with those obtained by the finite element *** comparison confirms the validity of the proposed dynamic model for the *** to the mentioned features,this model can be reliable for investigating the system’s vibrational behavior and implementing vibration control algorithms.

关键词： planar moving Timoshenko beam non-rigid non-elastic axial effect as-sumed mode method(Amm) nonlinear motion analysis

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 *** fibers are renowned for their good mechanical properties,abundance,and short cycle *** 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 *** different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the *** elastic properties of the composite are determined with the law of *** Hamilton’s principle,the governing equations of motion are *** generalized differential quadrature method(GDQm)is then applied to the equations to obtain 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 ***,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 ***,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)

Study of boundary layer characteristics during the landfalling of a Nisarga cyclone

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Tropical Cyclone Research and Review 2024年第2期13卷 55-71页

作者： Rani p.pawar prajna priyadarshini T.Dharmaraj Dada p.Nade mahendra N.patil Omkar m.patil N.Jeni Victor Sambhaji m.pawar D.G.Kanase Sunil D.pawar Indian Institute of Tropical meteorology Ministry of Earth SciencesPuneIndia Department of physics Bharati Vidyapeeth’s Dr.Patangrao Kadam Mahavidyalaya(Shivaji University Kolhapur)SangliIndia KSK Geomagnetic Research Laboratory IIGPrayagrajAllahabadIndia Department of physics Sanjay Ghodawat University KolhapurIndia

One of the most important parameters in meteorology is the mean wind proﬁle in the tropical cyclone boundary *** vertical proﬁle of wind speed and wind direction were measured during the period of the Nisarga cyclone from may 31st,2020,to June 5th,2020,using the newly installed phased Array Doppler Sodar system at the Center for Space and Atmospheric Science(CSAS),Sanjay Ghodawat University,Kolhapur(16.74◦N,74.37◦E;near India's western coast).Our analysis revealed that the maximum mean wind speed was 17 m/s on June 3,2020,at 10:00 *** also shows the change in wind direction from southwest to southeast on June 2 and 3,*** high-resolution reanalysis data in the domain,0–25◦N,65–110◦E,during the period from may 31st to June 5th,2020,revealed the variation of the atmospheric pressure of the Nisarga cyclone from 1000 to 1008 hpa,sea surface temperature(SST)between 30◦C and 31◦C,outgoing longwave radiation(OLR)between 100 and 240 Wm-2,wind speed between 3 and 15 m/s,and low values of vertical wind shear(VWS)were observed to the north of Nisarga *** observations may provide more insights for the study of boundary layer turbulence during cyclonic activities.

关键词： Doppler Sodar Tropical cyclone Atmospheric boundary layer Vertical turbulence intensity

multi-aspect analysis of ureteral access sheath usage in retrograde intrarenal surgery: A RIRSearch group study

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Asian Journal of Urology 2024年第1期11卷 80-85页

作者： Oktay Özman Hacı m.Akgül Cem Başataç Önder Çınar Eyüp B.Sancak Cenk m.Yazıcı Bülent Önal Haluk Akpınar Gaziosmanpasa Training and Research Hospital Urology ClinicİstanbulTurkey TekirdağNamık Kemal University School of MedicineDepartment of UrologyTekirdağTurkey Group Florence Nightingale Hospitals Department of UrologyİstanbulTurkey Zonguldak Bulent Ecevit University School of MedicineDepartment of UrologyZonguldakTurkey Çanakkale Onsekiz mart University School of MedicineDepartment of UrologyÇanakkaleTurkey İstanbul University-Cerrahpaşa Cerrahpaşa Medical FacultyDepartment of UrologyİstanbulTurkey

Objective:To evaluate the effect of ureteral access sheath(UAS)use and calibration change on stone-free rate and complications of retrograde intrarenal surgery(RIRS).methods:Data from 568 patients undergoing RIRS for kidney or upper ureteral stones were retrospectively ***,patients were compared after 1:1 propensity score matching,according to UAS usage during RIRS(UAS used[+]87 and UAS non-used[−]87 patients).Then all UAS+patients(n=481)were subdivided according to UAS calibration:9.5-11.5 Fr,10-12 Fr,11-13 Fr,and 13-15 *** outcomes of the study were the success and complications of ***:Stone-free rate of UAS+patients(86.2%)was significantly higher than UAS−patients(70.1%)after propensity score matching(p=0.01).Stone-free rate increased with higher caliber UAS(9.5-11.5 Fr:66.7%;10-12 Fr:87.0%;11-13 Fr:90.6%;13-15 Fr:100%;ppostoperative complications of UAS+patients(11.5%)were significantly lower than UAS−patients(27.6%)(p=0.01).Complications(8.7%)with 9.5-11.5 Fr UAS was lower than thicker UAS(17.2%)but was not statistically significant(p=0.09).UAS usage was an independent factor predicting stone-free status or peri-and post-operative complications(odds ratio[OR]3.654,95%confidence interval[CI]1.314-10.162;OR 4.443,95%CI 1.350-14.552;OR 4.107,95%CI 1.366-12.344,respectively).Conclusion:Use of UAS in RIRS may increase stone-free rates,which also increase with higher caliber *** usage may reduce complications;however,complications seemingly increase with higher UAS calibration.

关键词： Stone Retrograde intrarenal surgery Ureteral access sheath Urolithiasis Kidney

Enhanced quantum resources via two distant atom-cavity systems under the influence of atomic dissipation

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Communications in Theoretical physics 2024年第2期76卷 62-73页

作者： m Setodeh Kheirabady m K Tavassoly m Rafeie E Ghasemian Laser and Optics Group Faculty of PhysicsYazd UniversityYazd 89195-741Iran Department of Electrical Engineering Faculty of Intelligent Systems Engineering and Data SciencePersian Gulf UniversityBushehrIran

Quantum resources such as entanglement and coherence are the holy grail for modern quantum technologies. Although the unwanted environmental effects tackle quantum information processing tasks, suprisingly these key quantum resources may be protected and even enhanced by the implementation of some special hybrid open quantum systems. Here, we aim to show how a dissipative atom-cavity-system can be accomplished to generate enhanced quantum *** do so, we consider a couple of dissipative cavities, where each one contains two effective two-level atoms interacting with a single-mode cavity field. In practical applications, a classical laser field may be applied to drive each atomic subsystem. After driving the system, a Bell-state measurement is performed on the output of the system to quantify the entanglement and coherence. The obtained results reveal that the remote entanglement and coherence between the atoms existing inside the two distant cavities are not only enhanced, but can be stabilized, even under the action of dissipation. In contrast, the local entanglement between two atoms inside each dissipative cavity attenuates due to the presence of unwanted environmental ***, the local coherence may show the same behavior as the remote ***, the system provides the steady state entanglement in various interaction regimes,particularly in the strong atom-cavity coupling and with relatively large detuning. more interestingly, our numerical analyses demonstrate that the system may show a memory effect due to the fact that the death and revival of the entanglement take place during the interaction. Our proposed model may find potential applications for the implementation of long distance quantum networks. In particular, it facilitates the distribution of quantum resources between the nodes of large-scale quantum networks for secure communication.

关键词： remote entanglement and coherence atomic dissipation steady state entanglement Bell-statemeasurement

Effects of multiple shapes for steady flow with transformer oil+Fe_(3)O_(4)+TiO_(2) between two stretchable rotating disks

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Applied mathematics and mechanics(English Edition) 2024年第2期45卷 373-388页

作者： m.RAHmAN m.TURKYILmAZOGLU Z.mUSHTAQ Department of mathematics Mirpur University of Science and TechnologyMirpur 10250Pakistan Department of mathematics Hacettepe UniversityBeytepeAnkara 06532Turkiye

In this study,we examine the effects of various shapes of nanoparticles in a steady flow of hybrid nanofluids between two stretchable rotating *** steady flow of hybrid nanofluids with transformer oil as the base fluid and Fe_(3)O_(4)+TiO_(2)as the hybrid nanofluid is *** shapes of Fe_(3)O_(4)+TiO_(2)hybrid nanofluids,including sphere,brick,blade,cylinder,and platelet,are *** shape exists in the same volume of a *** leading equations(partial differential equations(pDEs))are transformed to the nonlinear ordinary differential equations(ODEs)with the help of similarity *** system of equations takes the form of ODEs depending on the boundary conditions,whose solutions are computed numerically by the bvp4c mATLAB *** outputs are compared with the previous findings,and an intriguing pattern is discovered,such that the tangential velocity is increased for the rotation parameter,while it is decreased by the stretching values because of the lower *** the reaction rate parameter,the concentration boundary layer becomes shorter,and the activation energy component increases the rate at which mass transfers come to the higher disk but have the opposite effect on the bottom *** ranges of various parameters taken into account are pr=6.2,Re=2,m=1.0,φ_(1)=φ_(2)=0.03,K=0.5,S=-0.1,Br=0.3,Sc=2.0,α_(1)=0.2,γ=0.1,E_(n)=2.0,and q=1.0,and the rotation factor K is within the range of 0 to 1.

关键词： transformer oil Brinkman number skin friction coefficient double rotating disk Nusselt number Sherwood number

Human leukocyte antigen compatibility and incidence of donorspecific antibodies in pediatric liver transplant recipients

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World Journal of Gastroenterology 2024年第33期30卷 3837-3845页

作者： melina U melere Flavia H Feier Jorge Neumann Antônio N Kalil Juliana de m montagner Luiza S Nader Carolina S da Silva marco Aurélio F Junior Gabriela p Coral Guilherme p Bobsin Cristina T Ferreira Department of Hepatology and Liver Transplantation Santa Casa de Porto AlegrePorto Alegre 90050170Rio Grande do SulBrazil Department of Hepato-biliary-pancreatic Surgery and Liver Transplantation Irmandade Santa Casa de Misericórdia de Porto AlegrePorto Alegre 90020-090Rio Grande do SulBrazil postgraduation program in medicine:Hepatology Federal University of Health Sciences of Porto AlegrePorto Alegre 90050-170Rio Grande do SulBrazil Laboratory of Transplantation Immunology Irmandade Santa Casa de Misericórdia de Porto AlegrePorto Alegre 90020-090Rio Grande do SulBrazil

BACKGROUND Antibody-mediated rejection following liver transplantation(LT)has been increasingly recognized,particularly with respect to the emergence of de novo donor-specific antibodies(DSAs)and their impact on graft *** substantial evidence for adult populations exists,research focusing on pediatric LT outcomes remains *** To investigate the prevalence of human leukocyte antigen(HLA)mismatches and DSA and evaluate their association with rejection episodes after pediatric *** A cohort of pediatric LT recipients underwent HLA testing at Santa Casa de porto Alegre,Brazil,between December 2013 and December *** patients who survived for>30 days after LT with at least one DSA analysis were *** classes I and II and cross-matches were *** presence of de novo DSA(dnDSA)was evaluated at least 3 months after LT using the Luminex®single antigen bead method,with a positive reaction threshold set at 1000 *** episodes were confirmed by liver *** Overall,67 transplanted children were analyzed;61 received grafts from living donors,85%of whom were related to ***-transplant DSA(class I or II)was detected in 28.3%of patients,and dnDSA was detected in 48.4%.The median time to DSA detection after LT was 19.7[interquartile range(IQR):4.3-35.6]*** rejection occurred in 13 patients at follow-up,with C4d positivity observed in 5/13 Liver *** median time to rejection was 7.8(IQR:5.7-12.8)*** presence of dnDSA was significantly associated with rejection(36%vs 3%,pmonths were 76%vs 100%and 58%vs 95%for patients with dnDSA anti-DQ vs those without,*** Our findings highlight the importance of incorporating DSA assessment into pre-and post-transplantation protocols for pediatric LT *** implications may include immunosuppression minimization strategies based on this analysis in pediatric LT recip

关键词： Human leukocyte antigens Donor-specific antibodies Liver transplantation pediatric Rejection

Enhancement of coercivity,permeability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites for memory and high frequency devices

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Journal of Rare Earths 2024年第6期42卷 1128-1135,I0005页

作者： I.Sardar m.D.Hossain m.S.Sikder m.N.I.Khan m.R.Rahman physics Discipline Khulna UniversityKhulna9208Bangladesh Department of physics Khulna University of Engineering&TechnologyKhulna9203Bangladesh Department ofComputer Science and Engineering Northern University of Business&Technology KhulnaKhulna9100Bangladesh material Science Division Atomic Energy CentreDhaka1000Bangladesh

Spinel cubic ferrites have huge applications in me mory and high frequency *** the improvement of these modern devices,the magnetic coercivity,permeability,and dielectric properties of a ferrite are the important *** article focuses on improving the magnetic coercivity,magnetic permeability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites,where x=0.00,0.06,and *** X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEm),energy dispersive X-ray(EDX),vibrating sample magnetometer(VSm),and an impedance analyzer were used to characterize the structural,magnetic,and dielectric properties of the *** XRD patterns indicate the formation of spinel cubic structure of the samples with a secondary peak(EuFeO_(3))for Eu doped *** densities and porosities of the samples follow an inverse trend,where the doped samples’lattice parameters are increased with the increment of rare earth Eu *** FTIR analysis also proves the spinel cubic phase of the *** average grain size of the ferrites is obtained via FESEm images,and it is increased from 121 to 198 *** analysis confirms that doping of the Eu content also changes other hysteresis loop properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ***,the coercivity of the Eu doped samples is greater than that of the mother alloy(x=0.00).The EDX study shows that there is no impurity contamination in the *** permeability and dielectric measurements show an improved quality factor of the Eu-doped samples with low magnetic and dielectric *** dependent resistivity and impedance analysis also show the improved *** the observed properties of the samples,all the investigated ferrites might be strong candidates for potential applications in memory devices,magnetic sensors,and high frequency applications.

关键词： Ferrites Raree arths Coercivity permeability EDX Resistivity

Long-term outcomes of urethral balloon dilation for anterior urethral stricture: A prospective cohort study

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Asian Journal of Urology 2024年第3期11卷 480-485页

作者： Ahmed m.Abdel Gawad Abhijit patil Abhishek Singh Arvind p.Ganpule Ravindra B.Sabnis mahesh R.Desai Department of Urology Muljibhai Patel Urological HospitalNadiadIndia Department of Urology Faculty of MedicineAl-Azhar UniversityDamiettaEgypt

Objective:To prospectively follow up a cohort of anterior urethral stricture disease patients managed with balloon dilation(BD)for 3 years to evaluate the long-term outcomes and to study factors that contribute to ***:This study included men who had urethral BD for significant anterior urethral stricture disease between January 2017 and march *** about the patient age,stricture characteristics,and recurrence date were recorded,along with information on postoperative indwelling catheter use and operative ***,information about the self-calibration procedure was collected and where available,free flow(FF)measurements during the follow-up period were recorded and *** was defined as a lack of symptoms and acceptable FF rates(maximum flow rate>12 mL/s).Results:The final analysis was conducted on 187 *** mean follow-up period was 37 *** long-term overall success rate at the end of our study was 66.8%.Our recurrence rate was 7.4%at 12 months,24.7%at 24 months,and reached 33.2%at the end of our *** time to recurrence ranged from 91 days to 1635 days,with a mean of 670 *** stricture-free survival was significantly shorter with lengthy peno-bulbar(p=0.031)and multiple strictures(p=0.015),and in the group of patients who were not committed to self-calibration protocol(ppost-procedural self-calibration was the most important factor that may have decreased the incidence of recurrence(odds ratioZ5.85).Adjuvant self-calibration after BD not only reduced the recurrence rate from 85.4%in the non-self-calibration group to 15.1%in the self-calibration one(pmproved the overall stricture-free survival and FF parameters.

关键词： Balloon dilation Internal urethrotomy Recurrence Self-calibration Urethral stricture