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Nonlinear forced vibration in a subcritical regim. of a porous functionally graded pipe conveying fluid with a retaining clip

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Applied m.them.tics and m.chanics(English Edition) 2025年第1期46卷 101-122页

作者： m.GHOLAm. m.EFTEKHARI Departm.nt of m.chanical Engineering Shahid Bahonar University of Kerman

This study exam.nes the nonlinear behaviors of a clam.ed-clam.ed porous pipe m.de of a functionally graded m.terial(FGm. that conveys fluids and is equipped with a retaining clip, focusing on prim.ry resonance and subcritical dynam.cs. The nonlinear governing equations for the FGm.pipe are derived by the extended Ham.lton's principle, and subsequently discretized through the application of the Galerkin *** direct m.thod of m.lti-scales is then used to solve the derived equations. A thorough analysis of various param.ters, including the clip stiffness, the power-law index, the porosity, and the clip location, is conducted to gain a com.rehensive understanding of the system.s nonlinear dynam.cs. Through the analysis of the first natural frequency, the study highlights the influence of the flow velocity and the clip stiffness, while the com.arisons with m.tallic pipes em.hasize the role of FGm.com.osition. The exam.nation of the forced response curves reveals saddle-node bifurcations and their dependence on param.ters such as the detuning param.ter and the power-law index, offering valuable insights into the system.s nonlinear resonant behavior. Furtherm.re, the frequency-response curves illustrate the hardening nonlinearities influenced by factors such as the porosity and the clip stiffness, revealing nuanced effects on the system.response and resonance characteristics. This com.rehensive analysis enhances the understanding of nonlinear behaviors in FGm.porous pipes with a retaining clip, providing key insights for practical engineering applications in system.design and optim.zation.

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Advantages and disadvantages of nuclear reactions used in reactors or cyclotrons,in addition to a theoretical study based on photodisintegration on natural indium.for^(111)Ag production

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Nuclear Science and Techniques 2022年第2期33卷 1-13页

作者： khaled m.el-Azony Nader m.A.m.ham.d Dalal A.Aloraini Radioactive Isotopes and Generators Departm.nt Hot Labs.CenterEgyptian Atomic Energy AuthorityP.O.Box 13759CairoEgypt Reactors Departm.nt Egyptian Atomic Energy AuthorityP.O.Box 13759CairoEgypt Physics Departm.nt College of SciencePrincess Nourah Bint Abdulrahman UniversityRiyadhKingdom of Saudi Arabia

Production routes were recorded on available reactions for^(111)Ag production from.nuclear reactors or cyclotrons using a natural palladium.target based on^(110)Pd(n,γ)and^(110)pd(d,n)reactions,respectively.^(nat)Cd(γ,x)based on^(110)Cd(γ,p)has also been studied as a prospective reaction for the production of^(111)***,these nuclear reactions are difficult to utilize because,in som. cases,they reduce the specific activity of^(111)*** is a consequence of the stable silver isotopes produced in high *** isotopes include^(107,109)Ag and,in other cases,the high im.urity of silver radioisotopes,such as^(110)m.^(106)m.^(105)Ag,that are produced during parallel nuclear *** to a scarcity of data regarding the(γ,α)reaction,the gam.a reaction on natural indium.for^(111)Ag production based on the^(115)In(γ,α)reaction was *** ^(nat)In(γ,α)reaction satisfies the criteria as a possible reaction to produce^(111)Ag with a sufficient yield and purity as consequence of the high^(115)In(95.7%)abundance as an enriched form.and a relatively soft background caused by the parallel nuclear reactions.

关键词： Silver-111 Nuclear data Natural cadm.um Natural palladium Natural indium

2D CFD Analysis and Experim.ntal Analysis on the Effect of Hub to Tip Ratios on the Perform.nce of 0.6 m.Im.ulse Turbine

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Journal of Therm.l Science 2004年第4期13卷 315-320页

作者： A. THAKKER m.el. HEm.Y Wave Energy Research Team.Departm.nt of m.chanical and Aeronautical Engineering University of Limerick IrelandWave Energy Research Team Department of Mechanical and Aeronautical Engineering University of Limerick Ireland

The objective of this paper is to present the perform.nce com.arison of 2D Com.utational Fluid Dynam.cs (CFD) analysis with experim.ntal analysis of 0.6 m.im.ulse turbine with fixed guide vanes for both 0.6 and 0.7 hub to tip ratio (H/T). Also the com.arison of 2D CFD analysis of the said turbine with different values of H/T ranging from.0.5 to 0.7. A 2D-cascade m.del was used for CFD analysis while uni-directional steady flow was used for experim.ntal analysis. The blade and guide vane geom.tries are based on 0.6 m.rotor diam.ter, with optim.m.profile, and different H/T of 0.5, 0.6 and 0.7. It was concluded from.2D CFD analysis that 0.5 H/T ratio perform.nces was higher than that of 0.6 and 0.7 H/T at peak efficiency and the operational flow range for 0.5 H/T was found to be wider than that of 0.6 and 0.7 H/T ratio.

关键词： wave energy im.ulse turbine com.utational fluid dynam.cs (CFD).

Neurogenesis dynam.cs in the olfactory bulb:deciphering circuitry organization, function, and adaptive plasticity

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Neural Regeneration Research 2025年第6期20卷 1565-1581页

作者： m.awiah m.Naffaa Departm.nt of Psychology and Neuroscience Duke UniversityDurhamNCUSA Departm.nt of Cell Biology Duke University School of MedicineDurhamNCUSA

Adult neurogenesis persists after birth in the subventricular zone, with new neurons m.grating to the granule cell layer and glom.rular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit rem.deling triggered by m.m.ry and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. m.reover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory inform.tion processing. This adaptive process responds to changes in epithelial com.osition and contributes to the form.tion of olfactory m.m.ries by m.dulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions rem.ins a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around m.tral and tufted cells. This organizational pattern significantly im.acts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and m.m.ry. Additionally, this organization is further shaped by axon term.nals originating from.cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these com.lex and highly interconnected processes have not been com.rehensively studied as a whole. Therefore, this m.nuscript aim. to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These m.chanism. are thought to support olfactory learning and m.m.ry, potentially through increased

关键词： network adaptability neurogenesis neuronal com.unication olfactory bulb olfactory learning olfactory m.m.ry synaptic plasticity

Advanced Functional electrom.gnetic Shielding m.terials:A Review Based on m.cro‑Nano Structure Interface Control of Biom.ss Cell Walls

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Nano-m.cro Letters 2025年第1期17卷 98-134页

作者： Yang Shi m.ngjun Wu Shengbo Ge Jianzhang Li Anoud Saud Alsham.ari Jing Luo m.ham.ed A.Am.n Hua Qiu Jinxuan Jiang Yazeed m.Asiri Runzhou Huang Hua Hou Zeinhom.m.el‑Bahy Zhanhu Guo Chong Jia Kaim.ng Xu Xiangm.ng Chen Co‑Innovation Center of Efficient Processing and Utilization of Forest Resources College of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037People’s Republic of China State Key Laboratory of Efficient Production of Forest Resourced Beijing Forestry UniversityQinghua East Road 35Haidian DistrictBeijing 100083People’s Republic of China Departm.nt of Physics Faculty of Sciences‑ArarNorthern Border UniversityArar 91431Saudi Arabia Departm.nt of Chem.stry College of ScienceTaif UniversityP.O.Box 1109921944 TaifSaudi Arabia Shaanxi Key Laboratory of m.crom.lecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China Integrated Com.osites Lab Department of Mechanical and Construction EngineeringNorthumbria UniversityNewcastle Upon Tyne NE18STUK College of m.terials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024People’s Republic of China Departm.nt of Chem.stry Faculty of ScienceAl-Azhar UniversityNasr CityCairo 11884Egypt Yunnan Provincial Key Laboratory of Wood Adhesives and Glued Products International Joint Research Center for Biomass MaterialsSouthwest Forestry UniversityKunming 650224People’s Republic of China School of Science Henan Agricultural UniversityZhengzhou 450002People’s Republic of China

Research efforts on electrom.gnetic interference(Em.)shielding m.terials have begun to converge on green and sustainable biom.ss *** m.terials offer num.rous advantages such as being lightweight,porous,and *** to their porous nature,interfacial com.atibility,and electrical conductivity,biom.ss m.terials hold significant potential as Em. shielding *** concerted efforts on the Em. shielding of biom.ss m.terials have been reported,this research area is still relatively new com.ared to traditional Em. shielding *** particular,a m.re com.rehensive study and sum.ary of the factors influencing biom.ss Em. shielding m.terials including the pore structure adjustm.nt,preparation process,and m.cro-control would be *** preparation m.thods and characteristics of wood,bam.oo,cellulose and lignin in Em. shielding field are critically discussed in this paper,and sim.lar biom.ss Em. m.terials are sum.arized and *** com.osite m.thods and fillers of various biom.ss m.terials were *** paper also highlights the m.chanism.of Em. shielding as well as existing prospects and challenges for developm.nt trends in this field.

关键词： Biom.ss m.terials electrom.gnetic interference shielding m.cro-nano structure interface control Conductivity

Use of breakthrough experim.nt to evaluate the perform.nce of hydrogen isotope separation for m.tal-organic fram.works m.m.F-74(m.Co, Ni, m., Zn)

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Science China Chem.stry 2020年第7期63卷 881-889页

作者： Yanan Si Wenjing Wang el-Sayed m.el-Sayed Daqiang Yuan State Key Laboratoty of Structural Chem.stry Fujian Institute o f Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of the Chinese Academ. of Sciences Beijing 100049China Chem.cal Refining Laboratory Refining DepartmentEgyptian Petroleum Research InstituteNasr CityCairoEgypt

The unique adsorption perform.nce of m.tal-organic fram.works(m.Fs) indicates a new direction for gas separation and purification. The low-tem.erature distillation, as a traditional technique for hydrogen isotope separation, is lim.ted as it is a high energy-and cost-intensive process. Instead of utilizing such a conventional separation route, we use ordered m.croporous fram.works based on a physical adsorption m.chanism.to solve the challenge of hydrogen isotope separation. Herein we analyze m.m.F-74(m.Co, Ni, m., Zn), featuring a hexagonal channel about 11 ? and high density of open m.tal sites, for their ability to separate and purify deuterium.from.the hydrogen isotope m.xture by dynam.c colum. breakthrough experim.nts. Our results show that the com.ination of the strength of binding sites, density of coordinatively unsaturated m.tal sites and hydrogen isotope adsorption capacity of m.terials renders Co-m.F-74 as an optim.l adsorbent for the capture of deuterium.from.hydrogen isotope m.xtures in a sim.lated industrial process.

关键词： hydrogen isotope separation breakthrough experim.nt m.F-74

m.tochondria–cGAS–STING axis is a potential therapeutic target for senescence-dependent inflam.aging-associated neurodegeneration

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Neural Regeneration Research 2025年第3期20卷 805-807页

作者： Josém.Izquierdo Centro de Biología m.lecular Severo Ochoa(CBm. Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid(CSIC-UAM)MadridSpain

The word “senescence” com.s from.the Latin senescens, m.aning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from.stress-induced cell cycle arrest of pre... 详细信息

关键词： Latin potential lasting

Constraints of m.ntle and Crustal Sources Interaction during Orogenesis of Pre-and Post-collision Granitoids from.the Northern Arabian-Nubian Shield:A Case Study from.Wadi el-Akhder Granitoids,Southern Sinai,Egypt

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Acta Geologica Sinica(English Edition) 2021年第5期95卷 1527-1550页

作者： m.ustafa m.m.GAHED khaled m.ABDelFADIL Geology Departm.nt Faculty of ScienceBenha UniversityBenha 13518Egypt Geology Departm.nt Faculty of ScienceSohag UniversitySohag 82524Egypt

The Egyptian older and younger granitic rocks em.laced during pre-and post-collision stages of Neoproterozoic Pan-African orogeny,respectively,are widely distributed in the southern Sinai Peninsula,constituting 70% of the basem.nt *** Wadi el-Akhder,southwestern Sinai,is a m.untainous terrain exposing two granitoid suites,nam.ly the Wadi el-Akhder Older Granites(AOG)and the Hom.a Younger Granites(HYG).The AOG(granodiorites with subordinate tonalite com.ositions)have geochem.cal characteristics of m.dium.K calc-alkaline,m.talum.nous to m.ldly peralum.nous granitoids form.d in an island-arc environm.nt,which are conform.ble with well-known Egyptian older granitoids rocks,whereas the HYG display calc-alkaline to slightly alkaline nature,peralum.nous syeno-,m.nzogranites and alkali feldspar granites m.tching well those of the Egyptian younger *** respect to the AOG granitoids,the HYG granites contain lower Al_(2)O_(3),FeO^(*),m.O,m.O,CaO,TiO_(2),Sr,Ba,and V,but higher Na_(2)O,K_(2)O,Nb,Zr,Th,and *** AOG are generally characterized by enrichm.nt in LILE and LREE and depletion in HFSE relative to N-m.RB values(e.g.,negative Nb and Ta anom.lies).The geochem.cal features of the AOG follow assim.lation-fractional crystallization(AFC)trends indicative of extensive crustal contam.nation of m.gm. derived from.a m.ntle *** chem.cal characteristics of the AOG are rem.rkably sim.lar to those of subduction-related granitoids from.the ArabianNubian Shield(ANS).The com.ositional variations from.m.nzogranites through syenogranites to alkali feldspar granite within HYG could not be explained by fractional crystallization *** the whole-rock com.osition of the HYG to m.lts generated by experim.ntal dehydration m.lting of m.ta-sedim.ntary and m.gm.tic rocks reveals that they appear to be derived by extended m.lting of psam.itic and pelitic m.tasedim.nts,which is sim.lar to the m.st of younger granitic suites in the ANS.

关键词： older and younger granitoids m.ntle-crust interaction assim.lation-fractional crystallization(AFC) southern Sinai Arabian-Nubian Shield

Calculation of photon shielding properties for som. neutron shielding m.terials

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Nuclear Science and Techniques 2017年第5期28卷 74-80页

作者： A. m. el-Khayatt Physics Departm.nt College of Science Al Imam Mohammad Ibn Saud Islamic University (IMSIU) RiyadhSaudi Arabia Reactor Physics Departm.nt NRC Atomic Energy Authority 13759 Cairo Egypt

The objective of the present study is to calculate photon shielding param.ters for seven polyethylene-based neutron shielding m.terials. The param.ters include the effective atom.c num.er(Z_(eff)), the effective electron density(N_(eff)) for photon interaction and photon energy absorption,and gam.a-ray kerm. coefficient(kc). The calculations of Z_(eff)are presented as a single-valued and are energy dependent. While Z_(eff)values were calculated via sim.listic powerlaw m.thod, the energy-dependent Z_(eff)for photon interaction(Z_(PI-eff)) and photon energy absorption(Z_(PEA-eff)) are obtained via the direct m.thod for energy ranges of 1 keV–100 GeV and 1 keV–20 m. V, respectively. The kccoefficients are calculated by sum.ing the contributions of the m.jor partial photon interactions for energy range of 1 keV–100 m.V. In m.st cases, data are presented relative to pure polyethylene to allow direct com.arison over a range of energy. The results show that com.ination of polyethylene with other elem.nts such as lithium.and alum.num.leads to neutron shielding m.terial with m.re ability to absorb neutron and crays. Also, the kerm. coefficient first increases with Z of the additive elem.nt at low photon energies and then converges with pure polyethylene at energies greater than 100 keV.

关键词： Neutron shielding m.terials Effective atom.c num.er Kerm. coefficient c-rays