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Surface hardness,thermal,optical,and photon attenuation coefficients assessment for dysprosium-doped tellurite glasses

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Journal of Rare Earths 2023年第7期41卷 1083-1090,I0004页

作者： hesham m.h.Zakaly d.E.Abulyazied h.A.Saudi B.m.Alotaibi Shams A.m.issa Institute of Physics and Technology Ural Federal UniversityYekaterinburg620002Russia Faculty of Science Al-Azhar UniversityAssuit BranchAssuit71524Egypt Polymer Lab Department of PetrochemicalsEgyptian Petroleum Research InstituteNasr CityCairoEgypt department of Physics Faculty of ScienceUniversity of TabukTabukSaudi Arabia Physics department Faculty of ScienceAl-Azhar University(Girls Branch)Nasr CityCairoEgypt department of Physics College of SciencePrincess Nourah Bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia

Using a melt-cooling process with the host glass,dy_(2)O_(3)(1 wt%,2 wt%,3 wt%,and 4 wt%) doped tellurite glasses were produced.A(65-x)TeO_(2)-20B_(2)O_(3)-10Al_(2)O_(3)-SGeO_(2)-xdy_(2)O_(3) glass system was analyzed by Xray *** patterns have a hump at 2θ=27°-29° and no sharp peaks,indicating that all the glass samples are *** Vickers microhardness determines how resistant a glass is to persistent deformation produced by a harder *** scanning calorimetry(dSC) at 300-550℃ was used to evaluate the thermal properties of the dy_x glass *** glass transition temperature T_g(small endothermic peak),start crystallization temperature T_x and crystallization temperature T_c can all be seen on the dSC thermogram(exothermic peaks).The UV-Vis transmittance and absorption spectra were *** optical data show that the values of E_d^(ir),E_g^(Ind) and E_U decrease as the amount of dy_(2)O_(3)increases,indicating a narrowing of the tails due to localized states in the forbidden gap.A concentration quenching event occurs when dy^(3+) concentrations are above a certain threshold(1%).The addition of dy_(2)O_(3) increases glass density,while the addition of other dy(Ⅲ) oxides increases sample *** radiation shielding values change as a consequence of density *** sample with the highest amount of dy_(2)O_(3)(dy_(4)) has stronger radiation shielding characteristics;hence,it is superior in terms of shielding outcomes at all energy *** dy_x samples can be used in various forms of ionizing radiation shielding.

关键词： melt-cooling process dSC dysprosium(Ⅲ)oxides Surface hardness Photon attenuation Rare earths

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The sexually dimorphic expression of glutamate transporters and their implication in pain after spinal cord injury

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Neural Regeneration Research 2025年第11期20卷 3317-3329页

作者： Jennifer m.Colón-mercado Aranza I.Torrado-Tapias Iris K.Salgado Jose m.Santiago Samuel E.Ocasio Rivera dina P.Bracho-Rincon Luis h.Pagan Rivera Jorge d.miranda department of Physiology University of Puerto RicoMedical Sciences CampusSan JuanPRUSA National Institutes of health National Human Genome Research InstituteBethesdaMDUSA Universidad Central del Caribe School of MedicineBayamónPRUSA University of Puerto Rico Carolina CampusCarolinaPRUSA Institute of Neurobiology San JuanPRUSA

In addition to the loss of motor function,~60% of patients develop pain after spinal cord *** cellular-molecular mechanisms are not well understood,but the data suggests that plasticity within the rostral,epicenter,and caudal penumbra of the injury site initiates a cellularmolecular interplay that acts as a rewiring mechanism leading to central neuropathic *** can lead to the formation of new connections triggering abnormal sensory *** excitatory glutamate transporters are responsible for the reuptake of extracellular glutamate which makes them a critical target to prevent neuronal hyperexcitability and *** previous studies showed a sexually dimorphic therapeutic window for spinal cord injury after treatment with the selective estrogen receptor modulator *** this study,we investigated the anti-allodynic effects of tamoxifen in male and female rats with spinal cord *** hypothesized that tamoxifen exerts anti-allodynic effects by increasing the expression of glutamate transporters,leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant *** and female rats received a moderate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control(placebo).We used von Frey monofilaments and the“up-down method”to evaluate mechanical *** treatment decreased allodynia only in female rats with spinal cord injury revealing a sexdependent *** expression profile of glutamatergic transporters(excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1)revealed a sexual dimorphism in the rostral,epicenter,and caudal areas of the spinal cord with a pattern of expression primarily on *** rodents showed a significantly higher level of excitatory amino acid transporter-1 expression while male rodents showed increased

关键词： allodynia central neuropathic pain EAAT-1/GLAST EAAT-2/GLT-1 glutamate transporters selective estrogen receptor modulator sexual dimorphism spinal cord injury trauma

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Improving electrical,optical and radiation shielding properties of polyvinyl alcohol yttrium oxide composites

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Journal of Rare Earths 2023年第12期41卷 2002-2009,I0007页

作者： Shams A.m.issa d.E.Abulyazied Albandari W.Alrowaily h.A.Saudi E.S.Ali A.m.A.henaish hesham m.h.Zakaly department of Physics Faculty of ScienceUniversity of TabukTabukSaudi Arabia Faculty of Science Al-Azhar UniversityAssiut BranchAssiut71524Egypt Polymer Lab Department of PetrochemicalEgyptian Petroleum Research InstituteNasr CityCairoEgypt department of Physics College of SciencePrincess Nourah Bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Physics department Faculty of ScienceAl-Azhar University(Girls Branch)Nasr CityCairoEgypt Institute of Physics and Technology Ural Federal UniversityYekaterinburg620002Russia Physics department Faculty of ScienceTanta UniversityTanta31527Egypt Istinye University Faculty of Engineering and Natural SciencesComputer Engineering DepartmentIstanbul34396Turkey

This research aims to study the impact of yttrium oxide on the radiation protection features of polyvinyl alcohol(PVA) for gamma shielding *** yttrium oxide(Y_(2)O_(3)) was instilled through the PVA matrix by different contents(x=0.1 wt%,0,3 wt%,0,7 wt%,0,9 wt%),The morphology of the prepared PVA/Y_(2)O_(3)composites was characterized using scanning electron microscopy(SEm).The samples were investigated using absorption edge,transmittance spectra and dielectric *** transmittance and the bandgap energy decrease as the Y2O3content increases while there is an increase in ε’ and ε" as well as the ac conductivity with the content increment of Y_(2)O_(3)till 0.7 wt%.The te mperature dependence of the dc conductivity was measured for all samples in the range of 260-460 K,and it increases with the temperature *** correlate the electrical characteristics of the PVA/Y_(2)O_(3)composites with their structure and evaluate electrical properties with the help of equivalent circuit matching with the experimentally electrical response in the impedance spectrum,the radiation protection properties were also investigated to get the radiation shielding performance of these PVA/Y_(2)O_(3)composite films with varying Y_(2)O(3)*** linear attenuation coefficient(μ),half value layer(T_(0.5)),and mass attenuation coefficient(μm) were *** to all obtained data,PVA/Y_(2)O_(3)composite films with various percentages(0.1 wt%,0.3 wt%,0.7 wt%,0.9 wt%) can be used as a radiation shielding material.

关键词： Yttriumoxide/PVA Electrical properties Optical properties Gamma shielding Rare earths

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The electrical impedance, AC conductivity and dielectric properties of phenol red compound investigated and modeled by an artificial neural network

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Communications in Theoretical Physics 2020年第10期72卷 139-148页

作者： h A m Ali d m habashy Physics department Faculty of EducationAin Shams UniversityRoxyCairo 11757Egypt

The impedance spectroscopy,electrical conductivity and electric modulus of bulk phenol red were measured,as a function of both frequency and *** neural networks(ANNs)were used for modeling its electrical *** two parts(real and imaginary)of its complex impedance(Z^*)were analyzed and the activation energy related to the electrical relaxation process was *** curves were plotted showing semicircles for the different *** AC electrical conductivity follows a power lawσac(ω)αω^η.The maximum barrier height Bm was derived for specific temperatures.A plausible mechanism for the AC conduction of bulk phenol red was deduced from the temperature reliance of the frequency *** dielectric data was analyzed using electric modulus as a *** addition,ANNs were used to model the impedance parts and the total electrical *** runs were tried,to obtain the best *** training and prediction results were compared to the equivalent experimental results,with a good match *** equation describing the experimental results was obtained mathematically,based on the use of *** outputs demonstrated that ANNs are an admirable tool for modeling experimental results.

关键词： phenol red impedance spectroscopy electric modulus neural network

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Preparation, Characterization, Biological Activity and 3d molecular modeling of mn（Ⅱ）, Co（Ⅱ）, Ni（Ⅱ）, Cu（Ⅱ）, Pd（Ⅱ） and Ru（Ⅲ） Complexes of Some Sulfadrug Schiff Bases

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Chinese Journal of Chemistry 2012年第4期30卷 881-890页

作者： EL-Ghamry,h.A. Sakai,K. masaoka,S. EI-Baradie,K.Y issa,R.m. Chemistry department Faculty of ScienceTanta UniversityTantaEgypt Chemistry department Faculty of ScienceKyushu UniversityFukuokaJapan Institute for molecular Science National Institutes of Natural SciencesJapan

mn（Ⅱ）, Co（Ⅱ）, Ni（Ⅱ）, Cu（Ⅱ）, Pd（Ⅱ） and Ru（Ⅲ） complexes of Schiff bases derived from the condensation of sulfaguanidine with 2,4-dihydroxy benzaldehyde （hL1）, 2-hydroxy-l-naphthaldehyde （hL2） and salicylaldehyde （hL3） have been synthesized. The structures of the prepared metal complexes were proposed based on elemental analysis, molar conductance, thermal analysis （TGA, dSC and dTG）, magnetic susceptibility measurements and spectroscopic techniques （IR, UV-Vis, and ESR）. In all complexes, the ligand bonds to the metal ion through the azomethine nitrogen and a-hydroxy oxygen atoms. The structures of Pd（Ⅱ） complex 8 and Ru（Ⅲ） complex 9 were found to be polynuclear. Two kinds of stereochemical geometries; distorted tetrahedral and distorted square py- ramidal, have been realized for the Cu（Ⅱ） complexes based on the results of UV-Vis, magnetic susceptibility and ESR spectra whereas octahedral geometry was predicted for Co（Ⅱ）, mn（Ⅱ） and Ru（Ⅲ） complexes. Ni（Ⅱ） com- plexes were predicted to be square planar and tetrahedral and Pd（Ⅱ） complexes were found to be square planar. The antimicrobial activity of the ligands and their metal complexes was also investigated against the gram-positive bac- teria Staphylococcus aures and Bacillus subtilis and gram-negative bacteria, Escherichia coli and Pesudomonas aeruginosa, by using the agar dilution method. Chloramphenicol was used as standard compound. The obtained data revealed that the metal complexes are more or less, active than the parent ligand and standard. The X-ray crys- tal structure of hL3 has been also reported.

关键词： sulfaguanidine transition metal complexes spectral studies biological activity crystal structure mo- lecular modeling

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Classification and technical target of water electrolysis for hydrogen production

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Journal of Energy Chemistry 2024年第8期95卷 554-576,I0012页

作者： Kahyun ham Sooan Bae Jaeyoung Lee Ertl Center for Electrochemistry and Catalysis Gwangju Institute of Science and Technology(GIST)123 Cheomdangwagi-RoBuk-guGwangju 61005South Korea department of heterogeneous Reactions Max Planck Institute for Chemical Energy ConversionStiftstr.34-36Mülheim an der RuhrGermany School of Earth Sciences and Environmental Engineering GIST123 CheomdangwagiroBuk-guGwangju 61005South Korea International Future Research Center of Chemical Energy Storage and Conversion Processes GIST123 CheomdangwagiroBuk-guGwangju 61005South Korea eSuS Co. Ltd.#408S6 BuildingSchool of Environment and Energy EngineeringGIST123 CheomdangwagiroBuk-guGwangju 61005South Korea

Continuous efforts are underway to reduce carbon emissions worldwide in response to global climate *** electrolysis technology,in conjunction with renewable energy,is considered the most feasible hydrogen production technology based on the viable possibility of large-scale hydrogen production and the zero-carbon-emission nature of the ***,for hydrogen produced via water electrolysis systems to be utilized in various fields in practice,the unit cost of hydrogen production must be reduced to$1/kg h_(2).To achieve this unit cost,technical targets for water electrolysis have been suggested regarding components in the *** this paper,the types of water electrolysis systems and the limitations of water electrolysis system components are *** suggest guideline with recent trend for achieving this technical target and insights for the potential utilization of water electrolysis technology.

关键词： Water electrolysis hydrogen production Technical target Electrochemistry

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Vibration suppression of magnetostrictive laminated beams resting on viscoelastic foundation

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Applied mathematics and mechanics(English Edition) 2020年第8期41卷 1269-1286页

作者： A.m.ZENKOUR h.d.EL-ShAhRANY department of mathematics Faculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia department of mathematics Faculty of ScienceKafrelsheikh UniversityKafrelsheikh 33516Egypt department of mathematics Faculty of ScienceBisha UniversityBisha 61922Saudi Arabia

The vibration suppression analysis of a simply-supported laminated composite beam with magnetostrictive layers resting on visco-Pasternak’s foundation is *** constant gain distributed controller of the velocity feedback is utilized for the purpose of vibration *** formulation of displacement field is proposed according to Euler-Bernoulli’s classical beam theory(ECBT),Timoshenko’s first-order beam theory(TFBT),Reddy’s third-order shear deformation beam theory,and the simple sinusoidal shear deformation beam ***’s principle is utilized to give the equations of motion and then to describe the vibration of the current *** on Navier’s approach,the solution of the dynamic system is *** effects of the material properties,the modes,the thickness ratios,the lamination schemes,the magnitudes of the feedback coefficient,the position of magnetostrictive layers at the structure,and the foundation modules are extensively studied and discussed.

关键词： vibration suppression laminated composite beam magnetostrictive material visco-Pasternak’s foundation

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Optimization Study of the Efficient Spindle

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Journal of Thermal Science 2008年第3期17卷 243-246页

作者： Y.d.Kim d.h.Chun m.S.Kang h.d.Kim Korea Textile machinery Research Institute School of Textiles Yeungnam University School of mechanical Engineering Andong National University

In the field of yarn dyeing, the most generally employed method is a type of package dyeing which uses a package of cheese stacked on a spindle made of a perforated tube. Spindles up to now, have been designed without considering the characteristics of dyeing liquid, focusing only on the geometric configuration which cause many problems such as lack of level dyeing. To improve the level dyeing and find the appropriate spindle configuration for the most effective dyeing process, this study examines the spindle flow-field in detail, using a computational method. Flow characteristics inside the spindle have been investigated with varying in porosity, porous diameter and the velocity of the flow. The results show that the total pressure of the flow through the spindle is used to overcome body force. The characteristics of the flow from the porous spindle could also be observed. Based on the results from this study, an effective spindle configuration for level-dyeing has been proposed.

关键词： Porosity Spindle Yarn dyeing Computational Fluid dynamics

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Interaction between B-doped C60 Fullerene and Glycine Amino Acid from First-Principles Simulation

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Chinese Physics Letters 2010年第4期27卷 83-86页

作者： m. d. Ganji h. Yazdani department of Chemistry Islamic Azad University Ghaemshahr branch Mazandaran Iran

The possibility of formation of complexes between glycine and boron doped C60 （C59B） fullerene is investigated and compared with that of C60 fullerene by using the density functional theory calculations. It has been found that the binding of glycine to C59B generated the most stable complexes via its carbonyl oxygen active site, with a binding energy of-37.89 kcal/mol, while the glycine molecule prefers to bind to the pure C60 cage via its amino nitrogen active site, consistent with the recent experimental and theoretical studies. We have also tested the stability of the most stable Gly-C59B complex with ab initio molecular dynamics simulation, carried out at room temperature. These indicate that the B-doped C60 fullerenes seem to be more suitable materials for bindings to proteins than pure C60 fullerenes.

关键词： Surfaces interfaces and thin films Biological physics Condensed matter: structural mechanical & thermal Chemical physics and physical chemistry

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Photo-induced Synthesis and Characterization of Poly(methyl methacrylate) Grafted Sodium Salt of Partially Carboxymethylated Guar Gum

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Chinese Journal of Polymer Science 2014年第12期32卷 1690-1703页

作者： J.h.Trivedi m.d.Thaker h.C.Trivedi P.G. department of Chemistry Sardar Patel University

Photo-induced graft copolymerization of methyl methacrylate（mmA） onto sodium salt of partially carboxymethylated guar gum（Na-PCmGG, dS = 0.291） was carried out in an aqueous medium using ceric ammonium nitrate（CAN） as photoinitiator to synthesize a novel graft copolymer, Na-PCmGG-g-PmmA, which may find its potential application as a metal adsorbent. The influences of synthesis variables such as concentrations of photoinitiator（CAN）, nitric acid and monomer（mmA） as well as reaction time, temperature and amount of substrate on the grafting yields were studied and the reaction conditions for optimum photo-grafting were evaluated. At optimum concentration, the maximum values of the grafting yields achieved were G = 271.61% and GE = 63.89%. The experimental results were found to be in very good agreement with the proposed kinetic scheme. The photo-graft copolymerization of mmA onto Na-PCmGG（ dS = 0.291） was also carried out in the presence and absence of ultraviolet radiation for studying the efficiency of the photoinitiator. The influence of carboxymethyl groups introduced onto the guar gum molecules with regard to its behavior towards ultra-violet radiation induced grafting with mmA was also investigated. Photo-grafting process was confirmed and the products were characterized with the help of the spectroscopic（1h-NmR and FTIR） and SEm techniques.

关键词： Photo-induced grafting methyl methacrylate Sodium salt of partially carboxymethylated guar gum Optimum reaction conditions Characterization.

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