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Kinematic analysis of flexible bipedal robotic systems

Applied mathematics and mechanics(English Edition) 2024年第5期45卷 795-818页

作者： R.FAZEL A.m.s.AFEI s.R.NEKOO Department of mechanical Engineering Shahid Bahonar University of KermanKerman ***Iran Departamento de Ingenieria de sistem.s.y Automatica Escuela Técnica Superior de IngenieriaUniversidad de SevillaSeville 41092Spain

In spite of its intrinsic complexities,the passive gait of bipedal robots on a sloping ramp is a subject of interest for numerous *** distinguishes the present research from.s.milar works is the consideration of flexibility in the constituent links of this type of robotic *** is not a far-fetched assumption because in the transient(impact)phase,due to the impulsive forces which are applied to the system,the likelihood of exciting the vibration modes increases ***,the human leg bones that are involved in walking are supported by viscoelastic m.s.les and ***,for achieving more exact results,it is essential to model the robot links with viscoelastic *** this end,the Gibbs-Appell formulation and Newton's kinematic impact law are used to derive the m.s. general form of the system.s.dynamic equations in the swing and transient phases of *** m.s. important issue in the passive walking motion of bipedal robots is the determination of the initial robot configuration with which the system could accomplish a periodic and stable gait solely under the effect of gravitational *** extremely unstable nature of the system.s.udied in this paper and the vibrations caused by the impulsive forces induced by the impact of robot feet with the inclined surface are some of the very serious challenges encountered for achieving the above-mentioned *** overcome such challenges,an innovative method that uses a combination of the linearized equations of motion in the swing phase and the algebraic motion equations in the transition phase is presented in this paper to obtain an eigenvalue *** solving this problem,the suitable initial conditions that are necessary for the passive gait of this bipedal robot on a sloping surface are *** effects of the characteristic parameters of elastic links including the modulus of elasticity and the Kelvin-Voigt coefficient on the walking stability of this type of

关键词： bipedal robot flexible link swing phase transient phase eigenvalue problem Kelvin-Voigt coefficient

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Evaluation of the seismic behavior of reinforced concrete structures with flat slab-column gravity frame and shear walls through nonlinear analysis methods

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 713-726页

作者： m.A.Najafgholipour s.Heidarian Radbakhsh E.Erfani Department of Civil and Environmental Engineering Shiraz University of TechnologyShiraz ***Iran Department of Building Civiland Environmental EngineeringConcordia UniversityMontréal H3G 1M8Canada

This paper presents an investigation of the seismic behavior of reinforced concrete(RC)structures in which shear walls are the main lateral load-resisting elements and the participation of flat slab floor systems is not considered in the seismic design *** this regard,the behavior of six prototype structures(with different heights and plan layouts)is investigated through nonlinear static and time history analyses,implemented in the Opensees *** results of the analyses are presented in terms of the behavior of the slab-column connections and their mode of failure at different loading ***,the global response of the buildings is discussed in terms of some parameters,such as lateral overstrength due to the gravity flat slab-column *** to the nonlinear static analyses,in structures in which the slab-column connections were designed only for gravity loads,the slab-column connections exhibited a punching mode of failure even in the early stages of ***,the punching failure was eliminated in structures in which a minimum transverse reinforcement recommended in ACI 318(2019)was provided in the slabs at joint ***,despite neglecting the contribution of gravity flat slab-column fram.s.in the lateral load resistance of the structures,a relatively significant overstrength was imposed on the structures by the gravity fram.s.

关键词： RC flat slab-column frames seismic behavior nonlinear analysis time history analysis

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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 em.s.ion 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

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mgO-attached graphene nanosheet(mgO@GNs)reinforced magnesium matrix nanocomposite with superior mechanical,corrosion and biological performance

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International Journal of minerals,metallurgy and materials 2024年第9期31卷 2062-2076页

作者： s.Abazari A.shamsipur H.R.Bakhsheshi-Rad m.s.soheilirad F.Khorashadizade s.s.mirhosseini Department of materials and metallurgical Engineering Amirkabir University of TechnologyTehran ***Iran Iranian National standards Organization of Hormozgan HormozganIran Advanced materials Research Center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran Department of materials and metallurgical Engineering Iran University of Science and TechnologyTehranIran

magnesium(mg)alloys are gaining great consideration as body implant materials due to their high biodegradability and ***,they suffer from low corrosion resistance and antibacterial *** this research,semi-powder metallurgy followed by hot extrusion was utilized to produce the magnesium oxide@graphene nanosheets/magnesium(mgO@GNs/mg)composite to improve mechanical,corrosion and cytocompatibility *** have revealed that the incorporation of mgO@GNs nanohybrids into mg-based composite enhanced microhardness and compressive *** vitro,osteoblast cell culture tests show that using mgO@GNs nanohybrid fillers enhances osteoblast adhesion and apatite *** presence of mgO@GNs nanoparticles in the composites decreased the opening defects,micro-cracks and micro-pores of the composites thus preventing the penetration of the corrosive solution into the *** demonstrated that the mgO@GNs/mg composite possesses excellent antibacterial properties because of the combination of the release of mgO and physical damage to bacterium membranes caused by the sharp edges of graphene nanosheets that can effectively damage the cell wall thereby facilitating penetration into the bacterial lipid ***,the mgO@GNs/mg composite with high mechanical strength,antibacterial activity and corrosion resistance is considered to be a prom.s.ng material for load-bearing implant applications.

关键词： metal matrix composites mgO@GNs nanohybrid strengthening mechanisms antibacterial activity biocompatibility

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有剖宫产史妇女子宫破裂的发病率和预后的系统性回顾

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世界核心医学期刊文摘（妇产科学分册） 2005年第1期1卷 1-1页

作者： Guise J. m. mcdonagh m.s. Osterweil P 石磊 Dept. of Obstetrics and Gynecology Oregon Health and Science University UHN-50 3183 SWSam Jackson Park Road Portland OR 97239-3098United States Prof

Objective: To evaluate the incidence and consequences of uterine rupture in women who have had a delivery by caesarean section. Design: systematic review. Data sources: medline, HealthsTAR, Cochrane Database of systematic Reviews, Cochrane Controlled Trials Register,National Centre for Reviews and Dissemination,reference lists, and national experts. studies in all languages were eligible if published in full. Review methods:methodological quality was evaluated for each study by using criteria from the United states Preventive services Task Force and the National Health service Centre for Reviews and Dissemination. Uterine rupture was categorised as asymptomatic or symptomatic. Results: We reviewed 568 full text articles to identify 71 potentially eligible studies, 21 of which were rated at least fair in *** with elective repeat caesarean delivery, trial of labour increased the risk of uterine rupture by 2.7 (95%confidence interval 0.73 to 4.73) per 1000 cases. No maternal deaths were related to rupture. For women attempting vaginal delivery, the additional risk of perinatal death from rupture of a uterine scar was 1.4 (0 to 9.8) per 10 000 and the additional risk of hysterectomy was 3.4 (0to 12.6) per 10 000. The rates of asymptomatic uterine rupture in trial of labour and elective repeat caesarean did not differ significantly. Conclusions: Although the literature on uterine rupture is imprecise and inconsistent,existing studies indicate that 370 (213 to 1370) elective caesarean deliveries would need to be performed to prevent one symptomatic uterine rupture.

关键词：子宫破裂系统性回顾 Cochrane 预防服务健康服务中心无症状型子宫切除围生期对照试验无显著性差异

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Large magnetocaloric effect and magnetic properties of EuRhO3

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Journal of Rare Earths 2024年第9期42卷 1724-1729页

作者： m.Lassri m.s.jieddine A.Elouafi A.El Hachmi s.El Ouahbi R.moubah Laboratory of Energy and materials Engineering (LGEm) University of Sultan Moulay SlimaneFaculty of Science and Technology (FST) Institute of Applied Physics (IAP)-school of Industrial management (EmINEs) Mohammed Ⅵ Polytechnic University National school of Applied sciences (ENsA) University of Sultan Moulay Slimane Laboratory of mechanics Production and Industrial Engineering (LMPGI)Higher School of Technology of Casablanca (ESTC)University of Hassan Ⅱ Casablanca Laboratory of Radiation on matter and Instrumentation (LRmI) Faculty of Science and Technology (FST) SettatHassan Ⅰ University Laboatory of Physics of Advanced materials and Thermic (LPmAT) Faculty of Science Ain Chock (FSAC)University of Hassan Ⅱ Casablanca

We report on the structural,magnetic,and magnetocaloric properties of *** oxidation states of Eu and Rh ions were studied using X-ray photoelectron spectroscopy（XPs）.It is found that the Eu ions are mainly in the divalent oxidation state while the Rh ions have+4 ***3powders are found to be antiferromagnetic with a second order magnetic transition at Neel temperature（TN=2.9 K）.Analysis of the magnetic susceptibility versus temperature data in terms of the Curie=Weiss law:(χ=C/（T-θW）) for T>TN,yields θW=-3.1 K and effective magne tic moment ■,which is close to the theoretical value ■.The magnetic entropy change(-Δsm),was determined by em ploying the thermodynam ic maxwell's *** μ0H=5 T and near TN,■ and relative cooling power（RCP） exhibit large values of 33.7 J/（kg·K） and 238 J/kg,*** large magnitude of-Δsmand RCP show that the EuRhO3compound could be a potential candidate to be used in cryogenic magnetic refrigeration.

关键词： X-ray photoelectron spectroscopy Cryogenic magnetic refrigeration magnetic properties magnetocaloric effect Rare earths

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structural effects induced by dialysis-based purification of carbon nanomaterials

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Nano materials science 2024年第4期6卷 475-483页

作者： A.D.Veloso A.m.Ferraria A.m.Botelho do Rego A.s.Viana A.J.s.Fernandes A.J.Fielding R.A.Videira m.C.Oliveira CQ-VR and Chem.s.ry Department University of Trás-os-Montes e Alto Douro BsIRG iBB-Institute for Bioengineering and BiosciencesDepartment of Chemical Engineeringand Associate Laboratory i4HB-Institute for Health and BioeconomyInstituto Superior TécnicoUniversidade de Lisboa Centro de Química Estrutural Institute of Molecular SciencesDepartamento de Química e BioquímicaFaculdade de CiênciasUniversidade de Lisboa I3N and Physics Department University of AveiroCampus de Santiago Faculty of science Pharmacy and Biomolecular SchoolLiverpool John Moores University REQUImTE/LAQV Laborat orio de FarmacognosiaDepartamento de QuímicaFaculdade de Farm aciaUniversidade do Porto

Dialysis plays a crucial role in the purification of nanomaterials but its impact on the structural properties of carbon nanomaterials was never ***,a carbon-based nanomaterial generated electrochemically in potassium phosphate buffer,was characterized before and after dialysis against pure *** is shown that dialysis affects the size of the carbon domains,structural organization,surface functionalization,oxidation degree of carbon,and grade of ***,dialysis drives the nanomaterial organization from discrete roundish carbon domains,with sizes ranging from 70 to 160 nm,towards linear stacking structures of small nanoparticles （m）.In parallel,alcohol and ether （epoxide） surface groups evolve into more oxidized carbon groups （e.g.,ketone and ester groups）.Investigation of the as-prepared nanomaterial by electron paramagnetic resonance （EPR） revealed a resonance signal consistent with carbon-oxygen centred ***,this study brings to light the selective affinity of the carbon nanomaterial under study to capture Na+ions,a property greatly enhanced by the dialysis process,and its high ability to trap oxygen,particularly before *** findings open new perspectives for the application of carbon-based nanomaterials and raise awareness of the importance of structural changes that can occur during the purification of carbon-based nanomaterials.

关键词： Nanocarbon surface functionalization NmR XPs Hydrophilic carbon Paramagnetic

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Computational Fluid Dynamics Approach for Predicting Pipeline Response to Various Blast scenarios: A Numerical modeling study

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Computer modeling in Engineering & sciences 2024年第9期140卷 2747-2777页

作者： Farman saifi mohd Javaid Abid Haleem.s.m.Anas Department of mechanical Engineering Jamia Millia Islamia(A Central University)New Delhi110025India Department of Civil Engineering Jamia Millia Islamia(A Central University)New Delhi110025India

Recent industrial explosions globally have intensified the focus in mechanical engineering on designing infras-tructure systems and networks capable of withstanding blast *** centered on high-profile facilities such as embassies and petrochemical plants,this concern now extends to a wider array of infrastructures and *** and scholars increasingly prioritize structural safety against explosions,particularly to prevent disproportionate collapse and damage to nearby *** has further amplified the reliance on oil and gas pipelines,making them vital for urban life and prime targets for terrorist ***,there is a growing imperative for computational engineering solutions to tackle blast loading on pipelines and mitigate associated risks to avert *** this study,an empty pipe model was successfully validated under contact blast conditions using Abaqus software,a powerful tool in mechanical engineering for simulating blast effects on buried *** a Eulerian-Lagrangian computational fluid dynamics approach,the investigation extended to above-surface and below-surface blasts at standoff distances of 25 and 50 *** descriptions in the numerical model relied on Abaqus’default mechanical *** analysis revealed varying pipe performance,with deformation decreasing as explosion-to-pipe distance *** explosion’s location relative to the pipe surface notably influenced deformation levels,a key finding highlighted in the ***,quantitative findings indicated varying ratios of plastic dissipation energy(PDE)for different blast scenarios compared to the contact blast(P0).specifically,P1(25 mm.s.bsurface blast)and P2(50 mm.s.bsurface blast)showed approximately 24.07%and 14.77%of P0’s PDE,respectively,while P3(25 mm above-surface blast)and P4(50 mm above-surface blast)exhibited lower PDE values,accounting for about 18.08%and 9.67%of P0’s PDE,***

关键词： Blast loading computational fluid dynamics computer modeling pipe networks response prediction structural safety

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Credit Card Fraud Detection Using Improved Deep Learning models

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Computers, materials & Continua 2024年第1期78卷 1049-1069页

作者： sumaya s.sulaiman Ibraheem Nadher sarab m.Hameed Computer science Department Al-Mustansiriya UniversityBaghdad10001Iraq Computer science Department University of BaghdadBaghdad10001Iraq Faculty of Basic Education Al-Mustansiriya UniversityBaghdad10001Iraq

Fraud of credit cards is a major issue for financial organizations and *** fraudulent actions become more complex,a demand for better fraud detection systems is *** learning approaches have shown prom.s. in several fields,including detecting credit card ***,the efficacy of these models is heavily dependent on the careful selection of appropriate *** paper introduces models that integrate deep learning models with hyperparameter tuning techniques to learn the patterns and relationships within credit card transaction data,thereby improving fraud *** deep learning models:AutoEncoder(AE),Convolution Neural Network(CNN),and Long short-Term memory(LsTm)are proposed to investigate how hyperparameter adjustment impacts the efficacy of deep learning models used to identify credit card *** experiments conducted on a European credit card fraud dataset using different hyperparameters and three deep learning models demonstrate that the proposed models achieve a tradeoff between detection rate and precision,leading these models to be effective in accurately predicting credit card *** results demonstrate that LsTm.s.gnificantly outperformed AE and CNN in terms of accuracy(99.2%),detection rate(93.3%),and area under the curve(96.3%).These proposed models have surpassed those of existing studies and are expected to make a significant contribution to the field of credit card fraud detection.

关键词： Card fraud detection hyperparameter tuning deep learning autoencoder convolution neural network long short-term memory resampling

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In search of a pan-coronavirus vaccine:next-generation vaccine design and immune mechanisms

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Cellular & molecular Immunology 2024年第2期21卷 103-118页

作者： s.Cankat m.U.Demael L.swadling Division of Infection and Immunity Institute of Immunity and TransplantationUniversity College LondonPears BuildingLondon NW32PPUK

members of the coronaviridae family are endemic to human populations and have caused several epidemics and pandemics in recent *** this review,we will discuss the feasibility of and progress toward the ultimate goal of creating a pan-coronavirus vaccine that can protect against infection and disease by all members of the coronavirus *** will detail the unmet clinical need associated with the continued transm.s.ion of sARs-CoV-2,mERs-CoV and the four seasonal coronaviruses(HCoV-OC43,NL63,HKU1 and 229E)in humans and the potential for future zoonotic *** will highlight how first-generation sARs-CoV-2 vaccines and natural history studies have greatly increased our understanding of effective antiviral immunity to coronaviruses and have informed next-generation vaccine *** will then consider the ideal properties of a pan-coronavirus vaccine and propose a blueprint for the type of immunity that may offer ***,we will describe a subset of the diverse technologies and novel approaches being pursued with the goal of developing broadly or universally protective vaccines for coronaviruses.

关键词： Vaccine Coronavirus Cross-reactive immunity Cross-protection Universal

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