检索结果-南通市图书馆

Dielectric Behavior of Modified Cellulose

在线全文

学校读者我要写书评

暂无评论

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

作者： el-henawii, s.a. s.a., 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 cons.a.ts.a.d 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.a.e more activated by treatment with ethylene diamine than with sodium hydroxide. Generally, silylation causes.a.marked decrease of the dielectric cons.a.t and dielectric loss, meanwhile the silylated samples.a.e affected with the pretreatment of linters with sodium hydroxide and ethylene diamine. (Edited author abstract) 28 Refs.

关键词： Cellulose

Effect of Accelerated Ageing on the Dielectric Behaviour of some Varnish Dry Films

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 1995年第5期11卷 323-328页

作者： s.a.el-henawii(Faculty of science, Helwan University, Cairo, Egypt) Helwan Univ Cairo Egypt

The variation of the dielectric cons.a.t e' and the dielectric loss e' of polyesteramide, alkyd polyesteramide and alkyd varnish dry films were measured within the frequency range from 105 to 107 Hz and the temperature range from 20 to 50℃. The varnish films were subjected to accelerated ageing by heating at 110℃ for diferent durations. The efect of the accelerated ageing on e' and e' were measured. The activation energy and the entropy change of dielectric relaxation for the dry films before and after ageing were also calculated. All the results obtained were recorded and discussed in correlation with the molecular structure of the investigated varnishes.

关键词： Effect of Accelerated Ageing on the Dielectric Behaviour of some Varnish Dry Films

some Dielectric Properties of some Resin Varnishes

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 1995年第2期11卷 119-121页

作者： s.a.el-henawii(Faculty of science, Helwan University, Cairo, Egypt) Heiwan Univ Cairo Egypt

The dielectric cons.a.t, the dielectric loss.a.d the power factor of three types of resins namely polyesteramide, alkyd polyesteramide and alkyd resins were measured with in the frequency range of 105 to 107 Hz and the temperature range of 20 to 50℃. The activation energy of dielectric relaxation and the entropy changes were also calculated using the us.a. rate equation. The results obtained are recorded and discussed.

关键词： some Dielectric Properties of some Resin Varnishes RT

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

在线全文

学校读者我要写书评

暂无评论

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.a.e also modified for ***,the similarity measures between pPyFHsss.a.e formulated with the assis.a.ce of numerical examples.a.d ***,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.a.sess the best educational institution is discussed to validate the suggested *** algorithmic results.a.e compared with the most pertinent model to evaluate the adaptability of pPyFHss.a. 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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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 *** s.a.ch 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.a. intelligent algorithm is *** steps of the suggested algorithm are explained with an example that explains *** compatibility of solid waste management sites.a.d systems is discussed,and rankings.a.e es.a.lished along with detailed justifications for their *** study’s strengths lie in its.a.plication 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.a.d 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

Anaerobic digestion for waste water poultry manure by UBF reactor

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental sciences 1997年第2期9卷 24-36页

作者： Ghanem I.I.Ibrahim Gu Guowei Zhu Jinfu Tayel,s.a. Khairy M.F.A. el-shimi,s.a. Agricultural Engineering Res.a.ch Institute Agricultural Research CenterMinistry Agriculture DukkiGizaEgypt school of Environmental Engineering Tongji UniversityShanghai200092China Agricultural Engineering Deptartment Faculty of AgricultureAt Azhar UniversityCairoEgypt soil and Water Res.a.ch Institute Agricultural Research CentreGizaEgypt

In this experiment the performance of UBF process treatment for wastewater chicken manure was tested under the condition of cons.a.t temperature of 35℃ and the volume of UBF is 4 liters. The experiment covered two s.a.es: the first was s.a.t up with phase I and phase II, the second was steady s.a.e. The following results.a.erage of operation period were obtained: (1) During the period of s.a.t up phase I operation the biogas production rate 0.39v/(***) at the volumetric COD loading rate of 2.97 kg COD/(m 3.d) with COD removal 76.85% and hydraulic retention time of 10.04 hours.a.d phase II the biogas production rate 3.86 v/(***) at the volume loading rate 11.69 kg COD/(m 3.d) have been achieved with COD removal 82.47% and HRT 16.45 hours. UBF process had resis.a.ce to the quantitative shock load. (2) During the steady s.a.e operation, the biogas production rate 9.83v/(***) at loading rate of 28.85 kg COD/(m 3.d) and COD removal efficiency 80.03% and hydraulic retention time of 18.73 hours have been achieved for this reactor. The operation of UBF reactor was very s.a.le.

关键词： anaerobic digestion UBF reactor poultry manure chicken manure waste water.

Dependence of nucleotide physical properties on their placement in codons.a.d determinative degree

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-science B(Biomedicine & Biotechnology) 2005年第10期6卷 948-960页

作者： BEREZHNOY A.Y. DUPLIJ s.a. NsC Kharkov Institute of Physics.a.d Technology Kharkov 61108 UkraineDepartment of Physics and Technology Kharkov National University Svoboda Sq.4 Kharkov 61077 Ukraine

Various physical properties such as dipole moment, heat of formation and energy of the most s.a.le formation of nucleotides.a.d bases were calculated by PM3 (modified neglect of diatomic overlap, parametric method number 3) and AM1 (austin model 1) methods. As distinct from previous calculations, for nucleotides the interaction with neighbours is taken into account up to gradient of convergence equaling 1. The dependencies of these variables from the place in the codon and the de- terminative degree were obtained. The difference of these variables for codons.a.d anticodons is shown.

关键词： Dipole moment, Heat of formation, Total energy, DNA, Codon, Anticodon, Determinative degree

Accurate modelling of the crush behaviour of thin tubular columns using material point method

在线全文

学校读者我要写书评

暂无评论

science China(Physics,Mechanics & Astronomy) 2013年第6期56卷 1209-1219页

作者： YANG PengFei MEGUID s.a. ZHANG Xiong school of Aeros.a.e Tsinghua University Mechanics.a.d Aeros.a.e Design Laboratory University of TorontoTorontoONM5S 3G8Canada

In this paper,we apply the material point method(MPM),also known as.a.meshfree method,to examine the crush behaviour of thin tubular *** the finite element method,randomly-distributed-weak-particle triggers were used to account for the deformation behaviour of collapse *** symmetric and asymmetric modes of deformation and their associated mean collapse loads.a.e determined for an elasto-plastic constitutive law describing the tubular *** was devoted to the accuracy and the convergence of the MPM simulation,which is determined by the number of the particles.a.d the size of the background cells used in our explicit ***,a novel contact approach was.a.opted to es.a.lish the crush behaviour of the tubular *** aspects of the work were accordingly examined,including three different crush velocities(5,10 and 15 m/s) and varied geometrical features of the tube(t/d and l/d) based on the deformation *** results of our model,which were compared with existing analytical predictions.a.d experimental findings,identify the critical geometric features of the tubular columns that would dictate the deformation mode as being either progressive collapse or following Euler's buckling mode.

关键词： thin tubular columns crush material point method deforamtiom mode elasto-plastic mean collapse load

Pore structure of cementitious material enhanced by graphitic nanomaterial： a critical review

在线全文

学校读者我要写书评

暂无评论

Frontiers of structural and Civil Engineering 2018年第1期12卷 137-147页

作者： s.a. GHAHARI E. GHAFARI L. AssI Department of Civil Engineering Purdue University USA Department of Civil and Environmental Engineering University of South Carolina USA

Carbon nano tubes （CNT） has been introduced as.a. efficient nanomaterial in order to improve the mechanical and durability properties of concrete. The effect of CNT on the microstructures of cementitious materials has been widely reported. This paper combines.a.critical review on the effect of CNT on the pore and microstructure of cement composite with a discussion on the porosity measurement of pastes containing CNT using mercury intrusion porosimetry techniques （MIP）. It was found that, surface treatment by H2sO4 and HNO3 solution forms carboxyl acid groups on CNTs＇ surfaces that lead to the improvement of reinforcement. In this scope, this review paper involves.a.alyzing the effect of CNT on the microstructure and the pore structure of cementitious materials. The existing methods of measuring the porosity of cementitious material are reviewed, in particular, the contact angle measurement is discussed in detail in which the most effective parameters.a.d possible errors of calculation is presented.

关键词： carbon nano tubes microstructure porosity mercury intrusion porosimetry cement composite