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Microstructural features of flower like Fe brushite

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Progress in Natural science:Materials international 2017年第4期27卷 520-526页

作者： s.i.el-dek s.F.Mansour M.A.Ahmed M.K.Ahmed Materials science and Nanotechnology Department Faculty of Post Graduate Studies for Advanced Science Beni-Suef University Physics Department Faculty of ScienceZagazig University Materials science Lab(1) Physics Department Faculty of Science Cairo University

The iron doped brushite(Fe-DCPD) nano particles were synthesized via co-precipitation method with Fe concentrations(0 ≤x≤ 1) in steps 0.2. The influence of iron concentration on the crystallinity, particle shape,morphology, optical, magnetic and electrical properties was investigated. The results showed that iron doping content is the crucial factor in the variation of physical properties. The particle shape changed from spheres at x=0.2 to be fiber network at x = 0.8. The saturation magnetization(Ms) increased from 0.4(emu/g) at x = 0.2 to 1.6(emu/g) at x = 0.8 which is considered more than four times with a considerable decrease of coercive field.

关键词： Bioceramic Calcium phosphate Brushite Fe brushite Magnetic hydroxyapatite

Nanofibrous ε-polycaprolactone scaffolds containing Ag-doped magnetite nanoparticles: Physicochemical characterization and biological testing for wound dressing applications in vitro and in vivo

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Bioactive Materials 2021年第7期6卷 2070-2088页

作者： M.K.Ahmed M.A.Zayed s.i.el-dek Mayssa Abdel Hady Doaa H.el sherbiny Vuk Uskokovic Faculty of Nanotechnology for Postgraduate studies Cairo UniversityEl-Sheikh Zayed 12588Egypt Department of Physics Faculty of ScienceSuez UniversitySuez 43518Egypt Chemistry Department Faculty of ScienceCairo University12613GizaEgypt Materials science and Nanotechnology Department Faculty of Postgraduate Studies for Advanced SciencesBeni-Suef UniversityBeni SuefEgypt Pharmaceutical Technology Department National Research CentreDokiiGizaEgypt Advanced Materials and Nanobiotechnology Laboratory TardigradeNano LLCIrvineCA92604USA Department of Biochemistry Faculty of DentistryModern University for Technology and InformationMokattamCairoEgypt

skin wounds can lead to numerous complications with dangerous health *** this work,magnetite nanoparticles were doped with different concentrations of antimicrobial silver(Ag)ions and incorporated into the electrospun nanofibrous ε-polycaprolactone(PCL)*** and scaffolds with various Ag contents were characterized using a range of physicochemical *** entered magnetite as cations and preferentially positioned at tetrahedral sites,introducing lattice distortions and topographic *** of the structure due to accommodation of Ag expanded the lattice in the bulk and contracted it on the surface,where broadened distribution of Fe-O coordinations was *** spin canting and diminishing the double exchange interaction through altered distribution of ferric and ferrous ions,Ag softened the magnetism of *** making the nanoparticle structure more defective,Ag modified the interface with the polymer and promoted the protrusion of the nanoparticles from the surface of the polymeric nanofibers,thus increasing their roughness and hydrophilicity,with positive repercussions on cell adhesion and *** the viability of human melanocytes and the antibacterial activity against *** and *** increased with the concentration of Ag in the magnetite phase of the *** wound healing rate in rats also increased in direct proportion with the concentration of Ag in the magnetite phase,and no abnormalities in the dermal and epidermal tissues were visible on day 10 in the treatment *** results imply an excellent potential of these composite nanofibrous scaffolds for use as wound dressings and in other reconstructive skin therapies.

关键词： Tissue engineering Wound healing skin Magnetic nanoparticles Nanofiber

A synergistic Multi-Attribute Decision-Making Method for Educational institutions Evaluation Using similarity Measures of Possibility Pythagorean Fuzzy Hypersoft sets

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Computer Modeling in Engineering & sciences 2025年第1期142卷 501-530页

作者： Khuram Ali Khan saba Mubeen ishfaq Atiqe Ur Rahman salwa el-Morsy Department of Mathematics University of SargodhaSargodha40100Pakistan Department of Mathematics University of Management and TechnologyLahore54000Pakistan Department of Mathematics College of ScienceQassim UniversityBuraydah51452Saudi Arabia

Due to the numerous variables to take into account as well as the inherent ambiguity and uncertainty,evaluating educational institutions can be *** concept of a possibility Pythagorean fuzzy hypersoft set(pPyFHss)is more flexible in this regard than other theoretical fuzzy set-like models,even though some attempts have been made in the literature to address such *** study investigates the elementary notions of pPyFHss including its set-theoretic operations union,intersection,complement,OR-and *** results related to these operations are also modified for ***,the similarity measures between pPyFHsss are formulated with the assistance of numerical examples and ***,an intelligent decision-assisted mechanism is developed with the proposal of a robust algorithm based on similarity measures for solving multi-attribute decision-making(MADM)problems.A case study that helps the decision-makers assess the best educational institution is discussed to validate the suggested *** algorithmic results are compared with the most pertinent model to evaluate the adaptability of pPyFHss,as it generalizes the classical possibility fuzzy set-like theoretical ***,while considering significant evaluating factors,the flexibility of pPyFHss is observed through structural comparison.

关键词： Hypersoft set Pythagorean fuzzy hypersoft set computational complexity multi-attribute decision-making optimization similarity measures uncertainty

solid Waste Management:A MADM Approach Using Fuzzy Parameterized Possibility single-Valued Neutrosophic Hypersoft Expert settings

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Computer Modeling in Engineering & sciences 2025年第1期142卷 531-553页

作者： Tmader Alballa Muhammad ihsan Atiqe Ur Rahman Noorah Ayed Alsorayea Hamiden Abd el-Wahed Khalifa Department of Mathematics College of SciencesPrincess Nourah bint Abdulrahman UniversityRiyadh11671Saudi Arabia 2 Department of Mathematics University of Management and TechnologyLahore54000Pakistan Department of Mathematics College of ScienceQassim UniversityBuraydah51452Saudi Arabia

The dramatic rise in the number of people living in cities has made many environmental and social problems *** search for a productive method for disposing of solid waste is the most notable of these *** scholars have referred to it as a fuzzy multi-attribute or multi-criteria decision-making problem using various fuzzy set-like approaches because of the inclusion of criteria and anticipated *** goal of the current study is to use an innovative methodology to address the expected uncertainties in the problem of solid waste site *** characteristics(or sub-attributes)that decision-makers select and the degree of approximation they accept for various options can both be indicators of these *** tackle these problems,a novel mathematical structure known as the fuzzy parameterized possibility single valued neutrosophic hypersoft expert set(ρˆ-set),which is initially described,is integrated with a modified version of sanchez’s *** this,an intelligent algorithm is *** steps of the suggested algorithm are explained with an example that explains *** compatibility of solid waste management sites and systems is discussed,and rankings are established along with detailed justifications for their *** study’s strengths lie in its application of fuzzy parameterization and possibility grading to effectively handle the uncertainties embodied in the parameters’nature and alternative approximations,*** uses specific mathematical formulations to compute the fuzzy parameterized degrees and possibility grades that are missing from the prior *** is simpler for the decisionmakers to look at each option separately because the decision is *** the computed results,it is discovered that they are consistent and dependable because of their preferred properties.

关键词： Hypersoft expert set sanchez’s method decision making optimization solid waste management possibility grade fuzzy parameterization

Physical and Dielectric Properties of some Nonionic surfactants

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Journal of Materials science & Technology 1998年第4期14卷 361-367页

作者： el-Anwar, i.M. el-Henawii, s.A. National Research Center Dokki Cairo Egypt Faculty of science Helwan University Egypt

Fatty acid esters have been prepared by reacting the acid C//1//8 with polyethylene glycols having varying numbers of oxyethylene units (4-88 units) by the direct esterification reaction method. surface and interfacial tensions were studied at various experimental conditions, including, concentration, temperature and chemical constitution of the surfactant. Critical micelle concentrations (CMC), surface excess and residual area occupied by each surface active agent molecule A have been calculated by using Gibb's equations. CMC values range from 10 to 55 multiplied by 10** minus **5 mole/L for all studied agents, while the residual area occupied by each molecule varies from 0.6 to 1.5 nm**2. Variation of CMC of some of these agents with temperature have been also examined and the obtained data were used to calculate the heat of micellization delta H//m and the entropy change during micellization delta s//m. Values of delta H//m vary from 14.63 kJ/mole to 2.717 kJ/mole depending on the chemical constitution of the agent under consideration. The apparent dipole moments mu of three surfactant were measured following the Headstrand's method. (Edited author abstract) 23 Refs.

关键词： surface active agents

sOME REsULTs ON THE COEFFiCiENTs OF iNTEGRATED EXPANsiONs OF ULTRAsPHERiCAL POLYNOMiALs AND THEiR iNTEGRALs

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Analysis in Theory and Applications 2001年第3期17卷 69-84页

作者： E.H.Doha s.i.el-soubhy Department of Mathematics Faculty of science Cairo UniversityGiza-Egypt Department of Mathematics Girl's College of EducationJeddahSaudi Arabia

The formula of expressing the coefficients of an expansion of ultraspherical polynomials that has been integrated an arbitrary number of times in terms of the coefficients of the original expansion is stated in a more compact form and proved in a simpler way than the formula of Phillips and Karageorghis (1990). A new formula is proved for the q times integration of ultraspherical polynomials, of which the Chebyshev polynomials of the first and second kinds and Legendre polynomials are important special cases. An application of these formulae for solving ordinary differential equations with varying coefficients is discussed.

关键词： differential equations Partial Differential Equations spectral Methods Chebyshev polynomials Legendre polynomials Numerical Analysis Boundary Value Problems spectral Approximation Parabolic Equations Applied Mathematics Accurate solution Fluid Dynamics Heat Transfer new formula Methods for

Dielectric Behavior of Modified Cellulose

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Journal of Materials science & Technology 1999年第2期15卷 164-168页

作者： el-Henawii, s.A. saad, s.M. el-Anwar, i.M. Faculty of science Helwan University Egypt Chemistry Department Faculty of Science Al-Azhar University Egypt Physical Chemistry Unit of the N.R.C Egypt

The dielectric constants and the dielectric loss, as well as the activation energy of dielectric relaxation of silylated cellulose were measured within the frequency range 10**5 to 10**7 Hz and the temperature range from 10 to 50 degree C. The test samples were activated cellulose with ethylene diamine, with sodium hydroxide and inactivated cellulose before and after silylation. The measurements were carried out using a multi-deka-meter. Cellulose molecules are more activated by treatment with ethylene diamine than with sodium hydroxide. Generally, silylation causes a marked decrease of the dielectric constant and dielectric loss, meanwhile the silylated samples are affected with the pretreatment of linters with sodium hydroxide and ethylene diamine. (Edited author abstract) 28 Refs.

关键词： Cellulose

Arctic sea-ice extent: No record minimum in 2023 or recent years

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Atmospheric and Oceanic science Letters 2025年第1期18卷 52-55页

作者： Ola M.Johannessen Tor i.Olaussen Nansen scientific society BergenNorway Nansen Environmental and Remote sensing Center BergenNorway

Arctic sea-ice extent reaches its minimum each year in september. On 11 september 2023 the minimum was 4.969 million square kilometers(***^(2)). This was not a record low, which occurred in 2012, when the minimum was 4.175 ***^(2), 0.794 ***^(2) less than the minimum in 2023. However, the ice extent had decreased by 0.432 ***^(2) compared with 2022. Nevertheless, the summer melting in 2023 was remarkably less than expected when considering the strong heat waves in the atmosphere and ocean, with record temperatures set around the world. in general, there is a high correlation between the long-term decrease in sea-ice extent and the increasing CO_(2) in the atmosphere, where the increase of CO_(2) in recent decades explains about 80% of the decrease in sea ice in september, while the remainder is caused by natural variability.

关键词： sea ice Arctic Minimum ice Climate

Coarse to Fine: The Role of severe Plastic Deformation in Advancing Titanium-Based Medical implants - A Comprehensive Review

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Journal of Wuhan University of Technology(Materials science) 2025年第1期40卷 295-306页

作者： Dragana R Mihajlović Bojan i Međo ivana Lj Cvijović-Alagić Veljko R Djokić Faculty of Technology and Metallurgy University of BelgradeKarnegijeva 411120 BelgradeSerbia Vinča institute of Nuclear sci-ences-National institute of the Republic of serbia University of Belgrade11001BeogradSerbia innovation Centre of the Faculty of Technology and Metallurgy Karnegijeva 411120 BelgradeSerbia

This paper describes severe plastic deformation(sPD)procedures,which are utilized to form an ultrafine-grained structure in metallic *** the sPD process,a solid material sample is subjected to very high loads without a significant change in sample *** the present work,the high-pressure torsion(HPT)process,as one of the sPD techniques,which achieves a high degree of deformation and ensures refinement of the microstructure,will be discussed in more *** that grain size control is accepted as a method to obtain materials with desired characteristics,an overview of the properties of ultrafine-grained titanium-based biomaterials to be used in medicine is ***,particular attention is dedicated to the influences of HPT process parameters,primarily hydrostatic pressure,and number of revolutions during torsion,on the grain size and physical and mechanical characteristics(modulus of elasticity,microhardness,and tensile properties),corrosion resistance,and biocompatibility of the titanium-based biomaterials.A review of the literature indicates that titanium-based materials obtained by the sPD process show improved mechanical and physical properties without losing biocompatibility and corrosion resistance,which suggests that these methods of obtaining implants are something that should be further developed in the future.

关键词： high-pressure torsion process ultrafine-grained titanium-based materials electrochemical anodization physical properties mechanical properties