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Alumina Effect on the Phase Transformation of 3Y-TZP Ceramics

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Journal of Materials science & Technology 2008年第6期24卷 873-877页

作者： Ezzat s.elshazly M.el-sayed Ali s.M.el-Hout Department of Metallurgy Nuclear Research CenterAtomic Energy AuthorityCairoEgypt

The isothermal tetragonal-to-monoclinic phase transformation of 3 mol fraction Y2O3-ZrO2 ceramics contain- ing different amounts of Al2O3 during ageing in water at 130℃ for periods of time up to 40 h was investigated to explore the effect of Al2O3 addition on this transformation. The propagation of the transformation into the specimen interiors was suppressed by the addition of Al2O3. The transformation kinetics showed a nucleation and growth mechanism on the specimen surface to be dominant in the low temperature ageing in water environment.

关键词： Phase transformation 3Y-TZP Al2O3 Kinetics

Influence of chemical modification by Y2O3 on eutectic si characteristics and tensile properties of A356 alloy

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Transactions of Nonferrous Metals society of China 2019年第7期29卷 1365-1374页

作者： M. E. MOUssA s. el-HADAD W. KHALIFA Department of Casting Technology Central Metallurgical Research and Development Institute (CMRDI) P. O. 87 Helwan Egypt Department of Mining Petroleum and Metallurgical Engineering Faculty of Engineering Cairo University P. O. 12613 Giza Egypt

The modification of A356 aluminum-silicon alloy using yttrium oxide (Y2O3) was studied. Addition levels of up to 2.5 wt.% Y2O3 were investigated. A premixed powder of Al-30wt.%Y2O3 was added to the melt at about 750℃ using vortex method. samples were then poured in sand mold. The results showed that evident modification was obtained using the Y2O3 addition. The optimum level was 1.5 wt.%, and was corresponding to a eutectic temperature depression from 568 to 557℃. The eutectic si particles were refined in length from 44.8 to 8.3 μm, and modified in aspect ratio from 6.8 to 0.98. Higher additions of Y2O3 caused de-modification of the eutectic si particles. The ductility of the modified specimens was enhanced by more than 20% compared to the unmodified ones. This was associated with a gradual transfer from cleavage to a more ductile mode of fracture.

关键词： hypoeutectic Al-si alloys modification yttrium oxide (Y2O3) ductility fracture mode

Magnetic properties of La2CuMnO6 double perovskite ceramic investigated by Monte Carlo simulations

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Chinese Physics B 2020年第5期29卷 387-391页

作者： s Mtougui I el Housni N el Mekkaoui s Ziti s Idrissi H Labrim R Khalladi L Bahmad Laboratoire de la Matière Condensée et des sciences Interdisciplinaires (LaMCscI) Mohammed V University of RabatFaculty of SciencesB.P.1014 RabatMorocco Intelligent Processing and security systems Mohammed V University of RabatFaculty of SciencesB.P.1014 RabatMorocco UsM/DERs/Centre National de l’Energie des Sciences et des Techniques Nucl´eaires(CNESTEN)RabatMorocco

We present a theoretical study of the magnetic properties of the lanthanum copper manganate double perovskite La2CuMnO6 ceramic,using Monte Carlo *** analyze and discuss the ground state phase diagrams in different planes to show the effect of every physical *** on the Monte Carlo simulations,which combine Metropolis algorithm and Ising model,we explore the thermal behavior of the total magnetization and *** also present and discuss the influence of physical parameters such as the external magnetic field,the exchange coupling interactions between magnetic atoms,and the exchange magnetic field on the magnetization of the ***,the critical temperature of the system is about Tc=70 K,in agreement with the experimental ***,the hysteresis loops of La2CuMnO6 are discussed.

关键词： double perovskite La2CuMnO6 Monte Carlo simulations Ising model hysteresis loops Metropolis algorithm critical temperature

Cyclic voltammetry,convolutive voltammetry,chrono-potentiometry and digital simulation studies of [Pt(C ≡ C tol)_2(dppm)_2Ir(CO)2]^+PF_6^- complex

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Chinese science Bulletin 2009年第20期54卷 3801-3807页

作者： el-Hallag s Ibrahim Chemistry Department Faculty of ScienceTanta University

The electrochemical behaviour of the heterobimetallic complex [Pt(C≡C tol)2(dppm)2-Ir(CO)2]+PF-6 was studied via cyclic voltammetry,convolutive voltammetry and chronopotentiometry at glassy carbon electrode in dichloromethane *** electrochemical parameters calculated from experimental data were tested and confirmed by matching the experimental cyclic voltammograms with the simulated *** was found that convolutive voltammetry provided higher sensitivity,better resolution and more accurate method for determination of the electrochemical parameters than ordinary cyclic voltammetry.

关键词：循环伏安法卷积伏安法计时电位法二氧化碳 DPPM 模拟数据电化学行为铂

Physio-biochemical and nutrient constituents of peanut plants under bentazone herbicide for broad-leaved weed control and water regimes in dry land areas

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Journal of Arid Land 2020年第4期12卷 630-639页

作者： Hani s sAUDY Ibrahim M el–METWALLY Goma A ABD el–sAMAD Agronomy Department Faculty of AgricultureAin Shams University68–Hadayek Shoubra 11241CairoEgypt Botany Departments National Research CentreEl–Behos St.Dokki 12622CairoEgypt

The abundance of broad-leaved weeds in peanut fields represents the handicap in weed management programs, since limited specific herbicides can be recommended to control them. Moreover, the physio-biochemical constituents and nutritional status in peanut plants as affected by available herbicides, i.e., bentazone under water stress conditions are not well known. Therefore, field trials were conducted during the growing seasons in 2016 and 2017 to investigate the interactional impact of irrigation levels(I_(50), I_(75) and I_(100), representing irrigation by 50%, 75% and 100% of crop evapotranspiration, respectively) and weed control practices(bentazone, bentazone+hoeing once, hoeing twice and weedy check as control) on dominant broad-leaved weeds as well as peanut physiological and agronomic traits. Result indicated that the efficiency of weed control for each weeded treatment under I_(50) significantly equaled with its counterpart under I_(75) or I_(100). Bentazone+hoeing once diminished weed biomass by 89.3% and enhanced chlorophyll content of peanut plants by 51.2%. Bentazone relatively caused a reduction in carotenoides. Hoeing twice and bentazone+hoeing once under I_(100) in both growing seasons as well as hoeing twice under I_(75) in 2017 were the superior combinations for boosting pod yield of peanut plants. Treatment of bentazone+hoeing once and I_(75) recorded the lowest reduction in N utilization percentage and the highest increase in potassium utilization percentage of peanut plants. eliminating weeds enhanced water use efficiency by 37.8%, 49.6% and 34.7% under I_(50), I_(75) and I_(100), respectively. In conclusion, peanut seems to be tolerant to bentazone at moderate water supply, thus it can be safely used in controlling the associated broad-leaved weeds.

关键词： biochemical traits drought nutritional status peanut productivity weed growth

Evaluation of Al and some of Its Alloys as Anode Materials vs γ-MnO_2 as Cathode Material and Ore Produced γ-MnO_2 vs Zn Anode in KOH solution

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Journal of Materials science & Technology 2006年第1期22卷 25-30页

作者： A.M.A.Hashem Kh.s.Abou-el-sherbini s.Zein el Abedin H.Abbas Inorganic Chemistry Department National Research CentreBehoes StreetDokkiCairoEgypt Physical Chemistry Department National Research CentreBehoes StreetDokkiCairoEgypt

In this study electrochemical performance of Al and some of its alloys （Al-Zn, Al-rvlg and Al-rvln） anodes vs MnO2 cathode were carried out in alkaline solution. The results show that the Al-Zn alloy anode has the best cell capacity among the other alloys. Cell capacity values go in the order Al-Zn〉Al-Mg〉Al〉Al-Mn. This result is probably related to the nature of passive films formed on the surface of the alloys which examined by scanning electron microscopy （sEM）. sEM morphologies of Al and its alloys showed coarse grains of passive films formed on the surface of these anode materials while Al-Mn morphology shows a needle-like structure. electrolytic manganese dioxide （EMD） produced by electrodepositing on platinum anode from liquor resulting from reduction of low grade pyrolusite ore （β-MnO2） by sulfur slag was characterized as cathode in alkaline Zn-MnO2 batteries. Ore produced sample （EMD1） was performed well in comparison with EMD standard （EMD2）（commercial battery grade electrolytic manganese dioxide, TOsOH-Hellas GH-s）. sEM morphology of Zn anode after cell reaction was carried out and showed that Zn anode has fine grains of passive film on its surface.

关键词： electrolytic MnO2 Zn Al Alkaline batteries

Modeling of nonlinear envelope solitons in strongly coupled dusty plasmas:Instability and collision

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Chinese Physics B 2015年第3期24卷 237-247页

作者： s.K.el-Labany E.F.el-shamy W.F.el-Taibany N.A.Zedan Department of Physics Faculty of ScienceDamietta University Department of Physics College of ScienceKing Khalid University Department of Physics College of Science for Girls in AbhaKing Khalid University

Modeling of instability and collision of nonlinear dust-acoustic（NDA） envelope solitons in strongly coupled dusty plasmas（sCDPs） is theoretically investigated. The sCDPs consists of strongly correlated negatively variable-charged dust grains and weakly correlated Boltzmann electrons and ions. Using the derivative expansion perturbation technique, a nonlinear schr dinger-type（NLsT） equation for describing the propagation of NDA envelope solitons is derived. Moreover,the extended Poincar′e–Lighthill–Kuo（EPLK） method is employed to deduce the analytical phase shifts and the trajectories after the collision of NDA envelope solitons. In detail, the results show that both modulation instability and phase shift after collision of NDA envelope solitons will modify with the increase in the effects of the viscosity, the relaxation time, and the dust charge fluctuation. Crucially, the modeling of dust-acoustic envelope solitons collision, as reported here, is helpful for understanding the propagation of NDA envelope solitons in strongly coupled dusty plasmas.

关键词： dust acoustic wave envelopes modulational instability head-on collision polarization effects

Generalized Green Correspondence of Graded Modules

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Chinese Annals of Mathematics,series B 2009年第4期30卷 413-420页

作者： salah el-Din s. HUssEIN Department of Mathematics Faculty of Science Ain Shams University Abasaya-Cairo 11566 Egypt.

The author studies the Green correspondence and quasi-Green correspondence for indecomposable modules over strongly graded rings. The motivation is to investigate the influence of induction and restriction processes o... 详细信息

关键词： Vertices sources Graded rings Graded modules Green correspondence

Cylindrical Three-Dimensional Dust-Ion Acoustic Propagation in Plasmas

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Communications in Theoretical Physics 2018年第9期69卷 325-330页

作者： s.K.el-Labany E.K.el-shewy H.N.Abd el-Razek A.A.el-Rahman Theoretical Physics Group Faculty of Science Domietta University Department of Physics Taibah University Theoretical Physics Group Faculty of Science Mansoura University Department of Physics Faculty of Science Assiut University

Wave properties of solitons in an unmagnetized four-component dusty plasma system contains isothermal distributed electrons, mobile ions, and negative-positive dusty grains have been examined. To study DIA wave properties,a reductive perturbation (RP) analysis is used. By a reductive perturbation (RP) analysis under convenient coordinate transformation, the three dimension Kadomtsev-Petviashvili equation in cylindrical coordinates is obtained. The effects of dust grain charge on soliton pulse structures are studied. More specifically, solitary profile depending on the axial,radial, and polar angle coordinates with time is discussed. This investigation may be viable in plasmas of the Earth’s mesosphere.

关键词： dust plasmas 3D-CKP equation dusty-ion acoustic solitary waves isothermal electrons