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

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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 constant 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

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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 constant, the dielectric loss and 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 usual rate equation. The results obtained are recorded and discussed.

关键词： some Dielectric Properties of some Resin Varnishes RT

Novel anlytical solution to the damped Kawahara equation and its application for modeling the dissipative nonlinear structures in a fluid medium

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Journal of Ocean Engineering and science 2022年第5期7卷 492-497页

作者： Noufe H.Aljahdaly s.a.el-Tantawy Department of Mathematics Faculty of Sciences and Arts-Rabigh campusKing Abdulaziz UniversityJeddahSaudi Arabia Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt Research Center for Physics(RCP) Department of PhysicsFaculty of Science and ArtsAl-MikhwahAl-Baha UniversitySaudi Arabia

A novel approximate analytical solution to the linear damped Kawahara equation using a suitable hypothesis is reported for the first *** on the exact solutions(such as solitary waves,cnoidal waves,etc.)of the undamped Kawahara equation,the dissipative nonlinear structures like dissipative solitons and cnoidal waves are *** obtained solution is considered a general solution,i.e.,it can be applied for studying the properties of all dissipative traveling waves described by the linear damped Kawahara *** technique is not limited to solve the linear damped Kawahara equation only,but it can be used for solving a large number of non-integrable evolution equations related to the realistic natural ***,the maximum global residual error in the whole space-time domain is estimated for checking the accuracy of the obtained *** obtained solutions can help many researchers in explaining the ambiguities about the mechanisms of propagation of nonlinear waves in complex systems such as seas,oceans,plasma physics,and much more.

关键词： semi-analytical solutions Damped Kawahara equation A collisional plasma Dissipative Kawahara solitons and cnoidal waves

The phase shift analysis of the colliding dissipative KdV solitons

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Journal of Ocean Engineering and science 2022年第6期7卷 521-527页

作者： Wedad Albalawi s.a.el-Tantawy sadah A.Alkhateeb Department of Mathematical sciences College of SciencePrincess Nourah bint Abdulrahman UniversityRiyadhSaudi Arabia Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt Research Center for Physics(RCP) Department of PhysicsFaculty of Science and ArtsAl-MikhwahAl-Baha UniversitySaudi Arabia Mathematics Department Faculty of ScienceUniversity of JeddahJeddahSaudi Arabia

In this work,the head-on collisions of the non-stationary dissipative soliton in ultracold neutral plasmas(UNPs)are *** extended Poincare-Lighthill-Kuo(PLK)approach is adopted for reducing the fluid equations of the UNPs to two-counterpropagating damped Korteweg-de Vries(dKdV)*** dKdV equation is not an integrable Hamiltonian system,i.e.,does not have an exact ***,one of the main goal of this paper is to find a new general approximate analytical solution to the dKdV equation for investigating the mechanism of the propagation and interaction of the non-stationary dissipative *** residual error is estimated for checking the accuracy of the new obtained *** approximate analytical soliton solutions are adopted for deriving the temporal phase shifts after the *** impact of physical parameters on the nonstationary dissipative soliton profile and the temporal phase shifts is *** obtained results will contribute to understand the mechanism of propagation and interaction of many nonlinear phenomena in different nonlinear mediums such as ocean,sea,optical fiber,plasma physics,etc.

关键词： Dissipative soliton collisions Damped Korteweg-de Vries equation The extended Poincare-Lighthill-Kuo method The temporal phase shifts

Experiment of“no-tillage”farming system on the volcanic soils of tropical islands of Micronesia

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International soil and Water Conservation Research 2014年第2期2卷 30-38页

作者： Mohammad H.Golabi s.a.el-swaify Clancy Iyekar College of Natural and Applied sciences University of Guam Division of soil College of AgricultureUniversity of Hawaii

The soils of southern Guam are formed from very deep;well-drained saprolite derived from volcanic based tuff and tuff *** soils suffer severe erosion as the result of rapid overland flow,wind and intensive rain events typical of southern *** integrated approach to control the accelerated soil erosion was designed to include conservation tillage,crop rotation with leguminous plant,and residue management for soil surface *** objectives of this study are;1)to evaluate the use of crop rotation and tillage management for increasing organic-matter content to improve the overall quality of these severely eroded soils,2)to evaluate the effect of conservation practices on harvested yield and crop productivity of these eroded soils and,3)to assess the effects of conservation techniques including no-tillage systems on water runoff and *** paper discusses the effect of conservation strategies and techniques on these severely eroded soils of southern Guam.

关键词： Conservation agriculture No-Tillage system Volcanic soils Micronesia Guam

synthesis and spectroscopic characterization of novel 2-amino-4,5,6,7-tetrahydro-3H-cyclopenta[d]pyrimidine and pyrimido[1,2-α]pyrimidine derivatives

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Chinese Chemical Letters 2015年第6期26卷 690-694页

作者： Mohamed s.a.el-Gaby Jehan A.Micky Nadia M.saleh Yousry A.Ammar Heba s.A.Mohamed Chemistry Department Faculty of ScienceAl-Azhar University at Assiut Chemistry Department Faculty of Science (Girl’s)Al-Azhar University Chemistry Department Faculty of ScienceAl-Azhar University Photochemistry Department National Research CenterEl-DokkiGizaEgypt

2-Aminocyclopenta[d]pyrimidines 3a-c were achieved via a one-pot, three-component reactions of cyclopentanone 1, aromatic aldehyde and guanidine hydrochloride （1：2：1 molar ratio）. Also, cyclization of 2,5-bis-（arylmethylidene）cyclopentanones 2 with guanidine hydrochloride （1：1 molar ratio） in methanol in the presence of sodium methoxide afforded cyclopenta-[d]pyrimidines 3. Compound 3c has been shown to be a useful building block for the synthesis of some novel pyrimido[ 1,2-a]pyrimidines 5, 7 and 12. The structures of the newly synthesized compounds were confirmed on the basis of analytical and spectral data,

关键词： Multicomponent reaction Cyclopenta[d]pyrimidine Pyrimido[1 2-a]pyrimidine Cyclopentanone

On the dynamics of nonlinear propagation and interaction of the modified KP solitons in multicomponent complex plasmas

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Journal of Ocean Engineering and science 2022年第6期7卷 555-564页

作者： Muhammad shohaib W.Masood R.Jahangir M.siddiq sadah A.Alkhateeb s.a.el-Tantawy COMsATs University Islamabad Islamabad CampusPark RoadChak ShahzadIslamabad 44000Pakistan National Center for Physics(NCP) Quaid-i-Azam University CampusShahdrah Valley RoadIslamabad44000Pakistan Mathematics Department Faculty of ScienceUniversity of JeddahJeddahSaudi Arabia Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt Research Center for Physics(RCP) Department of PhysicsFaculty of Science and ArtsAl-MikhwahAl-Baha UniversitySaudi Arabia

Dust-acoustic waves(DAWs)are analyzed in the small amplitude limit in a collisionless unmagnetized dusty plasma whose constituents are inertial dust grains,massless ions expressed by the generalized(r,q)distribution and inertialess Maxwellian electrons using the fluid theory of *** modified Kadomtsev-Petviashvili(mKP)equation is derived at a critical plasma condition for which the quadratic nonlinearity *** propagation of single soliton and interaction of two solitons are analyzed for the mKP equation in the context of plasma physics by employing Hirota bilinear *** effects of the flatness parameter rand tail parameter q of the ions on the frequency of the DAWs are studied and the comparison with Maxwellian and kappa distributions is *** the plasma parameters corresponding to the saturn’s E-ring,the range of electric field amplitude for dust-acoustic solitary waves(DAsWs)for different ion distributions is calculated and is shown to agree very well with the Cassini Wideband Receiver(WBR)*** interaction time of two DAsWs for non-Maxwellian ion distributions is estimated and shown to be fastest for the(r,q)distributed *** interesting feature of the interaction between compressive solitons with their rarefactive counterparts is also discussed in detail.

关键词： Non-Maxwellian complex plasmas Dust-acoustic solitary waves Hirota bilinear method Modified Kadomtsev-Petviashvili equation solitons interaction

Enhancing metformin efficacy with cholecalciferol and taurine in diabetes therapy:Potential and limitations

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World Journal of Diabetes 2025年第1期16卷 22-26页

作者： Gehan el-Akabawy Nabil Eid Department of Basic Medical sciences College of MedicineAjman UniversityAjman 346United Arab Emirates Department of Anatomy Division of Human BiologySchool of MedicineIMU UniversityKuala Lumpur 57000Malaysia

Diabetes mellitus,particularly type 2 diabetes mellitus(T2DM),poses a significant global health *** management strategies primarily focus on glycemic control;however,there is a growing need for comprehensive approaches addressing the complex pathophysiology of diabetes *** recent study by Attia et al explores the potential of a novel therapy combining metformin with cholecalciferol(vitamin D3)and taurine to mitigate T2DM-related complications in a rat *** findings indicate that this treatment combination improves glycemic control and reduces oxidative stress,inflammation,and lipid ***,the study is limited by a lack of safety profile data and in-depth molecular mechanism *** editorial critically highlights the study's strengths and weaknesses,compares it against other combination therapy research in T2DM,and underscores the need to explore further the mechanisms underpinning the observed therapeutic effects and investigate the safety profile of this novel approach.

关键词： Diabetes Metformin Cholecalciferol Taurine Hyperglycemia Oxidative stress Triglycerides

Atezolizumab and bevacizumab combination in advanced hepatocellular carcinoma patients:The imperative for safety assessment studies

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World Journal of Clinical Cases 2025年第9期13卷 56-59页

作者： Mina Tharwat Ahmed Tawheed Mohamed el-Kassas Department of Tropical Medicine and Gastroenterology Faculty of MedicineAswan UniversityAswan 81528Egypt Department of Endemic Medicine Faculty of MedicineHelwan UniversityCairo 11795Egypt

Hepatocellular carcinoma(HCC)is the most prevalent cancer of the hepatobiliary tract and the third leading cause of cancer-related mortality *** and bevacizumab combination is currently considered among the frontline treatment modalities for advanced unresectable *** studies examining this combination were focused on evaluating its *** numerous case reports documenting some side effects,there is a limited number of large-scale studies assessing these side *** this article,we comment on the case report by Park et al published recently,reporting a fatal intra-tumoral hemorrhage in a patient with HCC who received systemic therapy in the form of the combination of atezolizumab and bevacizumab.

关键词： Hepatocellular carcinoma Atezolizumab Bevacizumab Hemorrhage side effects