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A CONJUGATe GRADIeNT meTHOD FOR DISCReTe-TIme OUTPUT FeeDBACK CONTROL DeSIGN

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Journal of Computational mathematics 2012年第3期30卷 279-297页

作者： e1-Sayed m.e. mostafa Department of mathematics Faculty of Science Alexandria University Alexandria Egypt

In this paper, the discrete-time static output feedback control design problem is con- sidered. A nonlinear conjugate gradient method is analyzed and studied for solving an unconstrained matrix optimization problem that results from this optimal control prob- lem. In addition, through certain parametrization to the optimization problem an initial stabilizing static output feedback gain matrix is not required to start the conjugate gradi- ent method. Finally, the proposed algorithms are tested numerically through several test problems from the benchmark collection.

关键词： Output feedback control Nonlinear conjugate gradient methods Nonlinearprogramming.

A TRUST-ReGION ALGORITHm FOR SOLVING mINI-mAX PROBLem

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Journal of Computational mathematics 2018年第6期36卷 776-791页

作者： Bothina e1-Sobky Abdallah Abotahoun Department of mathematics Alexandria University Alexandria Egypt

In this paper, we propose an algorithm for solving inequality constrained mini-max optimization problem. In this algorithm, an active set strategy is used together with mul- tiplier method to convert the inequality constrained mini-max optimization problem into unconstrained optimization problem. A trust-region method is a well-accepted technique in constrained optimization to assure global convergence and is more robust when they deal with rounding errors. One of the advantages of trust-region method is that it does not require the objective function of the model to be convex. A global convergence analysis for the proposed algorithm is presented under some conditions. To show the efficiency of the algorithm numerical results for a number of test problems are reported.

关键词： mini-max problem Active-set multiplier method Trust-region Global con-vergence

Performance of the Aluminide Coating of SomeLow Alloy Steels

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Journal of materials Science & Technology 1997年第6期13卷 462-466页

作者： H.m.Soliman and m.e.Abd e1-Azim.m.tallurgy Dept., Atomic energy Authority, Cairo, egypt ) metallurgy Dept. Atomic Energy Authority Cairo Egypt

Two low alloy steels 0.5Cr-0.5mo-0.25V and H85 were pack-aluminized at 900°for 4 h by using Fe-Al powder mixture containing 48% Fe, 20.6% Al- 29.4% Al2O3 and 2% NH4Cl by weight. The microhardness and oxidation resistance at 900℃ of the aluminide coatings were studied. It was found that pack-aluminizing improves the microhardness of the 0.5Cro.5mo-0.25V steel while it reduces the microhardness of the H85 steel. Pack aluminizing highly improves the oxidation resistance after 20h exposure at 900℃ in air for the investigated steels.

关键词： Cr Performance of the Aluminide Coating of SomeLow Alloy Steels

Synthesis of Novel 3-Substituted PyridothienopyrimidineDerivatives with Biological evaluation as Antimicrobial Agents

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Chemical Research in Chinese Universities 2016年第6期32卷 967-972页

作者： Farag A. e1-essawy Nader m. Boshta Ayman K. eI-Sawaf Areal A. Nassar mohamed S. Khalafalah Preparatory Year Deanship Basic Science Department Prince Sattam Bin Abdulaziz University KSA Chemistry Department Faculty of Science Menoufia University Shebin EI-Koam Egypt Collage of Science and Humanitles Prince Sattam Bin Abdulaziz University KSA Faculty of education for Girls Prince Sattam Bin Abdulaziz University KSA

Novel 3-substituted pyridothienopyrimidine derivatives have been synthesized via the reaction of 2-{7,9-dimethyl-4-oxopyrido[3′,2′：4,5]thieno[3,2-d]pyrimidin-3（4H）-yl}acetohydrazide（5） with a variety of activereagents and chemicals. Structures of the newly synthesized compounds were established based on spectral *** resulting pyridothienopyrimidine derivatives were evaluated for their possible antimicrobial activity and some ofthem represent a new class of potentially antimicrobial compounds, especially compounds 9 and 18 which displayedthe highest activity against Gram-positive bacteria, Gram-negative bacteria, and Fungi in mIC range of 0.12--1.95 μg/mL.

关键词： Nitrogen-containing heterocycle Pyridothienopyrimidine Thieno[2,3-b]pyridine Antimicrobial

Column leaching of lanthanides from Abu Tartur phosphate ore with kinetic study

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Journal of Rare earths 2010年第4期28卷 576-580页

作者： A.T. Kandil m.m. Aly e.m. moussa A.m. Kamel m.m. Gouda m.N. Kouraim Chemistry Department Faculty of Science Helwan University Nuclear materials Authority P.O. Box 530 El Maadi Cairo Egypt

The dynamic leaching of lanthanides from a west desert phosphate ore, egypt (Abu Tartur) by hydrochloric acid, nitric acid and sulfuric acid solutions was investigated in this study as a function of acid concentration, flow rate and the presence of some additives such as boric acid. Also the kinetics of leaching of lanthanides was investigated as a function of temperature. It was found that the leaching process could be described by a shrinking-core model, with activation energy about 5.9, 13.8 and 21.9 kJ/...

关键词： column leaching lanthanides Abu Tartur hydrochloric acid nitric acid sulfuric acid kinetics rare earths

electron Spin Resonance of FeCl_3-filled Polyvinylidene Fluoride

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Journal of materials Science & Technology 1997年第3期13卷 194-198页

作者： A.Tawansi H.I.Abdel-Kader and e.m.Abdel-Razek(Dept. of Physics, Faculty of Science, mansoura University, 35516, egypt)m I Ayad(Dept. of Chemistry Almonofeya University, Shebeen e1-Koam, egypt) Dept. of Physics Faculty of Science Mansoura University Egypt Dept. of Chemistry Almonofeya University Shebeen El-Koam Egypt

electron spin resonance (eSR) measurements were carried out at room temperature (=294 K),for FeCl3-filled polyvinylidene fluoride (PVDF) films, over the filling mass fraction range of 0e films were prepared by casting method. The eSR spectrum of the unfilledPVDF was complex, due to the hyperfine interactions. arisen from the free radicals. For PVDF filled with FeCl3 nearly Symmetric Lorentzian eSR signals, without hyperfine spectra, were found around g=1.92. This is attributed to the superexchange magnetic interactions among the symmetrical octahedrally coordinated Fe3+ ions. The effect of the filling level on the following eSR parameters are discussed: signal asymmetry line width, g-factor, relaxation time, spin (and orbital) magnetic m.m.nt, number of unpaired electrons per Fe ion and density of spin electrons.

关键词： Figure Spin

L∞-Bounds of Solutions for Strongly Nonlinear elliptic Problems with Two Lower Order Terms

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Analysis in Theory and Applications 2017年第1期33卷 46-58页

作者： Youssef Akdim.m.hammed Belayachi mostafa e1 moumni Laboratory LSI Department of Mathematics Physics and Informatics Faculty Polydisciplinary of Taza University Sidi Mohamed Ben Abdellah P.O. Box 1223Taza Gare Morocco Department of mathematics Faculty of Sciences El Jadida University Chouaib Doukkali P.O. Box 20 24000 El jadida Morocco

In this work, we will prove the existence of bounded solutions m W0＇（f） N L （fl） for nonlinear elliptic equations - div（a（x,u, Vu））＋g（x,u,Vu）＋ H（x, Vu） = f, where a, g and H are Carath6odory function... 详细信息

关键词： L∞-estimate nonlinear elliptic equations rearrangement Sobolev spaces.

The sexually dimorphic expression of glutamate transporters and their implication in pain after spinal cord injury

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Neural Regeneration Research 2025年第11期20卷 3317-3329页

作者： Jennifer m.Colón-mercado Aranza I.Torrado-Tapias Iris K.Salgado Jose m.Santiago Samuel e.Ocasio Rivera Dina P.Bracho-Rincon Luis H.Pagan Rivera Jorge D.miranda Department of Physiology University of Puerto RicoMedical Sciences CampusSan JuanPRUSA National Institutes of Health National Human Genome Research InstituteBethesdaMDUSA Universidad Central del Caribe School of MedicineBayamónPRUSA University of Puerto Rico Carolina CampusCarolinaPRUSA Institute of Neurobiology San JuanPRUSA

In addition to the loss of motor function,~60% of patients develop pain after spinal cord *** cellular-molecular mechanisms are not well understood,but the data suggests that plasticity within the rostral,epicenter,and caudal penumbra of the injury site initiates a cellularmolecular interplay that acts as a rewiring mechanism leading to central neuropathic *** can lead to the formation of new connections triggering abnormal sensory *** excitatory glutamate transporters are responsible for the reuptake of extracellular glutamate which makes them a critical target to prevent neuronal hyperexcitability and *** previous studies showed a sexually dimorphic therapeutic window for spinal cord injury after treatment with the selective estrogen receptor modulator *** this study,we investigated the anti-allodynic effects of tamoxifen in male and female rats with spinal cord *** hypothesized that tamoxifen exerts anti-allodynic effects by increasing the expression of glutamate transporters,leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant *** and female rats received a moderate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control(placebo).We used von Frey monofilaments and the“up-down method”to evaluate mechanical *** treatment decreased allodynia only in female rats with spinal cord injury revealing a sexdependent *** expression profile of glutamatergic transporters(excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1)revealed a sexual dimorphism in the rostral,epicenter,and caudal areas of the spinal cord with a pattern of expression primarily on *** rodents showed a significantly higher level of excitatory amino acid transporter-1 expression while male rodents showed increased

关键词： allodynia central neuropathic pain eAAT-1/GLAST eAAT-2/GLT-1 glutamate transporters selective estrogen receptor modulator sexual dimorphism spinal cord injury trauma

Occurrence mechanism of silicate and aluminosilicate minerals in Sarcheshmeh copper flotation concentrate

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International Journal of minerals,metallurgy and materials 2009年第5期16卷 494-499页

作者： H.R.Barkhordari1 e.Jorjani1 A.eslami m.Noaparast mining engineering Department Science and Research BranchIslamic Azad UniversityPoonakHesarakTehranIran R&D Division-Sarcheshmeh Copper Complex RafsanjanIran School of mining engineering University College of EngineeringUniversity of TehranTehranIran

The Sarcheshmeh copper flotation circuit is producing 5× 10^4 t copper concentrate per month with an averaging grade of 28% Cu in rougher, cleaner and recleaner stages. In recent years, with the increase in the open pit depth, the content of aluminosilicate minerals increased in plant feed and subsequently in flotation concentrate. It can motivate some problems, such as unwanted consumption of reagents, decreasing of the copper concentrate grade, increasing of Al2O3 and SiO2 in the copper concentrate, and needing a higher temperature in the smelting process. The evaluation of the composite samples related to the most critical working period of the plant shows that quartz, illite, biotite, chlorite, orthoclase, albeit, muscovite, and kaolinite are the major Al2O3 and SiO2 beating minerals that accompany chalcopyrite, chalcocite, and covellite minerals in the plant feed. The severe alteration to clay minerals was a general rule in all thin sections that were prepared from the plant feed. Sieve analysis of the flotation concentrate shows that Al2O3 and SiO2 bearing minerals in the flotation concentrate can be decreased by promoting the size reduction from 53 to 38 μm. Interlocking of the Al2O3 and SiO2 bearing minerals with chalcopyrite and chalcocite is the occurrence mechanism of silicate and aluminosilicate minerals in the flotation concentrate. The dispersed form of interlocking is predominant.

关键词： copper aluminosilicate silicate flotation