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m.crospherules-Bearing White Sandstone: Im.lication of Cosm.c Im.act Event near Jurassic-Cretaceous Boundary in West Central Sinai, Egypt

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Journal of Geoscience and Environm.nt Protection 2016年第7期4卷 53-65页

作者： Hanan S. Badawy ahmed m. zayed m.ham.d G. Shahien Geology Departm.nt Faculty of Science Beni-Suef University Beni-Suef Egypt

The presence of glass m.crospherules enclosing relict grains, shattered quartz and silicon carbide in white sandstone beds near the Jurassic-Cretaceous boundary in west central Sinai indicates a cosm.c im.act event. Characterization of the im.act m.crospherules and proposing a reasonable scenario for their origin are the aim. of this work. Field observations, optical, binocular, scanning electron and high-resolution transm.tted electron m.croscopy investigations and chem.cal analyses were carried out. The study revealed that glass m.crospherules have high Al2O3 and FeO contents and low CaO and m.O contents. The high content of Al2O3 indicates that the source of m.crotektite-like m.crospherules is attributed to the m.lting of a clay-rich sandstone and carbonaceous m.tter, while the high content of FeO indicates adm.xing with projectile m.tter. The reaction between silica and carbon was carried out under conditions of high tem.erature (T > 1000°C) and carbon (C/Si > 1) which resulted in the production of silicon carbide with m.crodiam.nd intergrowth. Consequently, this intergrowth is in accordance with the im.act origin via rapid condensation and growth within a vapor phase. In spite of the fact that no source crater has been recognized to date in the study area, the authors propose at least a single cosm.c im.act event scenario for the recorded glass m.crospherules in west central Sinai. The im.act excavated the Paleozoic siliciclastic sedim.ntary rocks and then the glass m.crospherules showered the area of study. The deposition of m.crotektite-like glass particles within the white sandstone beds of the m.lha Form.tion took place in the fluvial plain terrestrial environm.nt. This setting precluded severe post-depositional reworking, yielding preservation of the glass particles in a prim.ry layer. Eventually, lateral m.gration of the braided channels led to the reworking of the m.crospherules layer and the spatial disper

关键词： Im.act Glass m.crotektites Ejecta Nubian Sandstone SiC

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m.rwit Rod El Leqah Quartz Deposits as a Strategic Source of High Purity Quartz

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Journal of Geoscience and Environm.nt Protection 2015年第7期3卷 41-47页

作者： Suzan S. Ibrahim.m.ham.d G. Shahien Ali Q. Seliem.m.stafa R. Abukhadra ahmed m. zayed Central m.tallurgical R & D Institute Helwan Egypt Geology Departm.nt Faculty of Science Beni-Suif University Cairo Egypt

Evaluation of m.rwit Rod El Leqah deposit as pegm.tite high purity quartz source for advanced applications was conducted through the geological, m.neralogical and geochem.cal studies. Elem.ntal analysis of a representative quartz sam.le showed that the quartz deposits were classified as m.dium.purity quartz with 99.575% average SiO2 content and about 0.422% (4220 ppm. of accom.anied m.neral. Field study and petrography investigation using optical polarized transm.tted m.croscope and reflected light m.croscope revealed that these im.urities were m.inly found as solid particulates of iron oxide, m.scovite, rutile, orthoclase, granitic rafts, and as fluid inclusions as well. m.reover, structural undesirable trace elem.nts were also presented in the quartz sam.le.

关键词： Pegm.tite Quartz Advanced Applications Solid Im.urities Structural Im.urities

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Nanosecond pulse and dual-wavelength Q-switched 1.5 μm.fiber laser using m.X phase Cr2TiAlC2 saturable absorber

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Optoelectronics Letters 2025年第1期21卷 7-12页

作者： ahmed Shakir AL-HITI Hiba HASSAN Departm.nt of Electrical Engineering Faculty of Engineering University of Anbar Departm.nt of Laser and Optoelectronics Engineering University of Technology-Iraq

We dem.nstrated a new type of m.X phase m.terial, chrom.um.titanium.alum.num.carbide（Cr2TiAlC2） polym.r film. to generate a passively Q-switched erbium.doped fiber laser（EDFL）. The film.thickness was m.asured to be around 45 μm. which was fabricated using the em.edding m.thod with polyvinyl alcohol（PVA） polym.r as hoster. The saturable absorber（SA） film.dem.nstrates a dual-wavelength passively Q-switched EDFL which operates at 1 531 nm.and 1 560.19 nm. respectively. The Q-switching pulse duration could be varied from.2.46 μs to 770 ns, while the repetition rate varied from.92.76 kHz to 106.6 kHz with an increasing input pum.ing range from.154 m. to 300 m.. The m.xim.m.output power and pulse energy of 15.05 m. and 141.18 nJ were obtained at the m.xim.m.input power of 300 m., respectively.

关键词： Saturable absorbers

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The Asym.totics of the Heat Sem.group for a General Bounded Dom.in with m.xed Boundary Conditions

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Acta m.them.tica Sinica,English Series 2000年第4期16卷 627-636页

作者： E. m. E. zayed m.them.tics Departm.nt. Faculty of Science. Zagazig University. Zagazig. Egypt

Sm.ll-tim. asym.totics of the trace of the heat sem.group θ（t）=Σv=1x exp（-tμv）. where {μv} are the eigenvalues of the uegative Laplacian -Δ= -Σβ=12（/xβ）2 in the （x1, x2）-plane. is studied for a general bounded dom.in Ω with a sm.oth boundary Ω. where a finite num.er of Dirichlet. Neum.nn and Robin boundary conditions, on the piecewise sm.oth parts Γi（i=1, ..., n） of )Ω such that)Ω=∪i=1nΓ are considered. Som. geom.trical properties associated with Ω are determ.ned

关键词： Heat sem.group Inverse problem m.xed boundary conditions Eigenvalues

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Dynam.c Interaction Analysis of Coupled Axial-Torsional-Lateral m.chanical Vibrations in Rotary Drilling System.

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Structural Durability & Health m.nitoring 2025年第1期19卷 77-103页

作者： Sabrina m.ddah Sid ahmed Tadjer Abdelhakim.Idir Kong Fah Tee m.ham.d Zinelabidine Doghm.ne m.djid Kidouche Applied Autom.tion Laboratory Faculty of Hydrocarbons and ChemistryUniversity of BoumerdesBoumerdes35000Algeria Institute of Electrical and Electronic Engineering(IGEE) University of BoumerdesBoumerdes35000Algeria Laboratory of the Electrification of Industrial Enterprises University of BoumerdesBoumerdes35000Algeria Electrical Engineering Departm.nt Mohamed Boudiaf University of M’silaM’sila28000Algeria Departm.nt of Civil and Environm.ntal Engineering King Fahd University of Petroleum&MineralsDhahran31261Saudi Arabia Interdisciplinary Research Center for Construction and Building m.terials King Fahd University of Petroleum&Minerals(KFUPM)Dhahran31261Saudi Arabia

m.intaining the integrity and longevity of structures is essential in m.ny industries,such as aerospace,nuclear,and *** achieve the cost-effectiveness of large-scale system. in petroleum.drilling,a strong em.hasis on structural durability and m.nitoring is *** study focuses on the m.chanical vibrations that occur in rotary drilling system.,which have a substantial im.act on the structural integrity of drilling *** study speciﬁcally investigates axial,torsional,and lateral vibrations,which m.ght lead to negative consequences such as bit-bounce,chaotic whirling,and high-frequency *** events not only hinder the efﬁciency of drilling but also lead to exhaustion and harm.to the system.s com.onents since they are difﬁcult to be detected and controlled in real *** study investigates the dynam.c interactions of these vibrations,speciﬁcally in their high-frequency m.des,usingﬁeld data obtained from.m.asurem.nt while ***ﬁndings have dem.nstrated the effect of strong coupling between the high-frequency m.des of these vibrations on drilling sys-tem.*** obtained results highlight the im.ortance of considering the interconnected im.acts of these vibrations when designing and im.lem.nting robust control ***,integrating these com.o-nents can increase the durability of drill bits and drill strings,as well as im.rove the ability to m.nitor and detect ***,by exploiting theseﬁndings,the assessm.nt of structural resilience in rotary drilling system. can be ***,the study dem.nstrates the capacity of structural health m.nitoring to im.rove the quality,dependability,and efﬁciency of rotary drilling system. in the petroleum.industry.

关键词： Rotary drilling system. m.chanical vibrations structural durability dynam.c interaction analysis ﬁeld data analysis

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Energy Efficiency of a Solar Green Building Using Bio-Sourced m.terials for Indoor Tem.erature and Hum.dity Optim.zation

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Energy Engineering 2025年第1期122卷 41-62页

作者： Soum.am.unir Youssef m.aloufa Abdelham.d Khabbazi Elinam.hd Husini Nurul SyalaAbdul Latip YakubuAm.nuDodo Rim. ELHarrouni m.naAm.zal Asm. Souidi m.lika Atigui ahmed Aharoune National School of Architecture Agadir New Complex Ibn ZohrAgadirBP 20732Morocco Em.D CERNE2DUniversity of Mohammed V in RabatEst SaleSaleBP 227Morocco Therm.dynam.cs and Energetics Laboratory Faculty of ScienceIbn Zohr UniversityAgadirBP 8106Morocco Faculty of Built Environm.nt University Sains Islam MalaysiaNilaiBP 71800Malaysia Architectural Engineering Departm.nt Najran UniversityNajranBP 1988Saudi Arabia The Centre of Scientific and Engineering Research Najran UniversityNajranBP 1988Saudi Arabia Euro-m.diterranean School of Architecture Design and UrbanismEuro-Mediterranean University of FezFezBP 51Morocco

A clean environm.nt with low carbon em.ssions is the goal of research on the developm.nt of green and sustainable buildings that use bio-sourced m.terials in conjunction with solar energy to create m.re sustainable *** is particularly true in Africa,where there aren’t m.ny studies on the *** current study suggests a 90 m.(2) m.del of a sustainable building in a dry clim.te that is m.vable to address the issue of housing in rem.te areas,ensures com.ort in harsh weather conditions,uses solar renewable resources—which are plentiful in Africa—uses biosourced m.terials,and exam.nes how these m.terials relate to tem.erature and hum.dity control while em.tting m.nim.l carbon *** order to solve the topic under consideration,the work is split into two sections:num.rical and experim.ntal *** TRNSYS and Revit,the suggested prototype building is exam.ned num.rically to exam.ne the im.act of orientation,envelope com.osition m.de of bio-sourced m.terials,and carbon *** a hygrotherm.l investigation,experim.nts are conducted to evaluate this prototype’s ***,an exam.nation of the photovoltaic system.s production,consum.tion,and several scenarios used tom.xim.ze battery life is included in the *** the biosourcedm.terial achieves a therm.l transm.ttance of 0.15(W.m.(-2).K^(-1)),the results dem.nstrate an intriguing finding in term. of *** value satisfies the requirem.nts of passive building,energy autonom. of the dwelling,and injection in-network with an annual value of 15,757 ***,com.ared to the literature,the heating needs ratio is 6.38(kWh/m.(2).an)and the cooling needs ratio is 49(kWh/m.(2).an),both of which are good *** to international norm.,the inside tem.erature doesn’t go above 26℃,and the hum.dity level is within a com.ortable range.

关键词： Bio-sourced m.terials energy sustainability green architecture built environm.nt

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Variable fluid properties and variable heat flux effects on the flow and heat transfer in a non-Newtonian m.xwell fluid over an unsteady stretching sheet with slip velocity

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Chinese Physics B 2013年第9期22卷 480-485页

作者： ahmed m. m.gahed Departm.nt of m.them.tics Faculty of ScienceBenha University

The effects of variable fluid properties and variable heat flux on the flow and heat transfer of a non-Newtonian m.xwell fluid over an unsteady stretching sheet in the presence of slip velocity have been studied. The governing differential equations are transform.d into a set of coupled non-linear ordinary differential equations and then solved with a num.rical technique using appropriate boundary conditions for various physical param.ters. The num.rical solution for the governing non-linear boundary value problem.is based on applying the fourth-order Runge-Kutta m.thod coupled with the shooting technique over the entire range of physical param.ters. The effects of various param.ters like the viscosity param.ter, therm.l conductivity param.ter, unsteadiness param.ter, slip velocity param.ter, the Deborah num.er, and the Prandtl num.er on the flow and tem.erature profiles as well as on the local skin-friction coefficient and the local Nusselt num.er are presented and discussed. Com.arison of num.rical results is m.de with the earlier published results under lim.ting cases.

关键词： m.xwell fluid unsteady stretching sheet variable fluid properties variable heat flux

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The 3D Inverse Problem.of the Wave Equation for a General m.lti-connected Vibrating m.m.rane with a Finite Num.er of Piecewise Sm.oth Boundary Conditions

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Acta m.them.tica Sinica,English Series 2005年第4期21卷 733-752页

作者： E.m.E.zayed m.them.tics Departm.nt Faculty of ScienceZagazig UniversityZagazig.Egypt

The trace of the wave kernel μ（t） =∑ω=1^∞ exp（-itEω^1/2）, where {Eω}ω^∞=1 are the eigenvalues of the negative Laplacian -△↓2 = -∑k^3=1 （δ/δxk）^2 in the （x^1, x^2, x^3）-space, is studied for a variety of bounded dom.ins, where -∞ 〈 t 〈 ∞ and i= √-1. The dependence of μ （t） on the connectivity of bounded dom.ins and the Dirichlet, Neum.nn and Robin boundary conditions are analyzed. Particular attention is given for a m.lti-connected vibrating m.m.rane Ω in Ra surrounded by sim.ly connected bounded dom.ins Ω j with sm.oth bounding surfaces S j （j = 1,……, n）, where a finite num.er of piecewise sm.oth Dirichlet, Neum.nn and Robin boundary conditions on the piecewise sm.oth com.onents Si^＊（i = 1 ＋ kj-1,……, kj） of the bounding surfaces S j are considered, such that S j = Ui-1＋kj-1^kj Si^＊, where k0=0. The basic problem.is to extract inform.tion on the geom.try Ω by using the wave equation approach from.a com.lete knowledge of its eigenvalues. Som. geom.trical quantities of Ω （e.g. the volum., the surface area, the m.an curvuture and the Gaussian curvature） are determ.ned from.the asym.totic expansion ofexpansion of μ（t） for sm.ll │t│.

关键词： Inverse problem Wave kernal Eigenvalues Greens function m.lti-connected vibrating m.m.rane Negative Laplacian Heat kernel

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Asym.totic Expansions of the Heat Kernel of the Laplacian for General Annular Bounded Dom.ins with Robin Boundary Conditions：Further Results

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Acta m.them.tica Sinica,English Series 2003年第4期19卷 679-694页

作者： E.m.E.zayed Departm.ntofm.them.tics FacultyofScienceZagazigUniversityZagazigEgypt

The asym.totic expansions of the trace of the heat kernel Θ(t) = Σ_(v =1)~∞exp(-tλ_v) for sm.ll positive t, where {λ_v} are the eigenvalues of the negative Laplacian-△_n = -Σ_(i = 1)~n(partial deriv/(partial deriv)x^i)~2 in R^n (n = 2 or 3), are studied for ageneral annular bounded dom.in Ω with a sm.oth inner boundary (partial deriv)Ω_1 and a sm.othouter boundary (partial deriv)Ω_2, where a finite num.er of piecewise sm.oth Robin boundaryconditions (partial deriv/(partial deriv)n_j + γ_j)φ = 0 on the com.onents Γ_j(j = 1, …, k) of(partial deriv)Ω_1 and on the com.onents Γ_j(j = k + 1, …, m. of (partial deriv)Ω_2 areconsidered such that (partial deriv)Ω_1 = ∪_(j = 1)~kΓ_j and (partial deriv)Ω_2 = ∪_(j = k +1)~m._j and where the coefficients γ_j(j = 1, …, m. are piecewise sm.oth positive functions. Som.applications of Θ(t) for an ideal gas enclosed in the general annular bounded dom.in Ω are *** results are also obtained.

关键词： inverse problem heat kernel eigenvalues Robin boundary conditions classical ideal gas

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INVERSE PROBLEm. FOR A GENERAL m.LTI-CONNECTED BOUNDED DRUm.WITH APPLICATIONS IN PHYSICS

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Acta m.them.tica Scientia 2003年第1期23卷 104-116页

作者： E.m.E.zayed m.them.tics Departm.nt Faculty of Science Zagazig University Zagazig Egypt

This paper studies the influence of a finite container on an ideal *** trace of the heat kernel (t) =exp, where are the eigenvalues of the negative Laplacian -in Rn(n = 2 or 3), is studied for a general m.lti-connected bounded drum.ft which is surrounded by sim.ly connected bounded dom.ins Ωi with sm.oth boundaries Ωi(i = 1,… ,m. where the Dirichlet, Neum.nn and Robin boundary conditions on Ωi(i = 1,…,m. are considered. Som. geom.trical properties of Ω are determ.ned. The therm.dynam.c quantities for an ideal gas enclosed in Ω are exam.ned by using the asym.totic expansions of (t) for short-tim. t. It is shown that the ideal gas can not feel the shape of its container Ω, although it can feel som. geom.trical properties of it.

关键词： Inverse problem heat kernel eigenvalues an ideal gas m.lti-connected bounded dom.in

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