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Superconducting parameter determination for (Co0.5Zn0.5Fe2O4)x/Cu0.5Tl0.5-1223 composite

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Journal of Advanced Ceramics 2016年第3期5卷 210-218页

作者： M.ME.BARAKAT N.AL-SAYYED R.AWAD a.i.abou-aly Physics Department Faculty of Science Alexandria University Alexandria Egypt Physics Department Faculty of Science Beirut Arab University Beirut Lebanon

The addition of magnetic Co0.5Zn0.5Fe2O4 nanoparticles to the superconducting Cu0.5Tl0.5-1223 phase has been used to investigate the electrical resistivity behavior of the composite above the superconducting transition temperature T c. This was studied according to the opening of spin gap and fluctuation conductivity. The results indicated that the pseudogap temperature (T*) and superconducting fluctuation temperature (T scf) change by increasing the addition of Co0.5Zn0.5Fe2O4 nanoparticles. it was found that T* is related to hole carrier concentration P and it also depends on the antiferromagnetic fluctuation affected by magnetic nanoparticles. The excess-conductivity analysis showed four different fluctuation regions started from high temperature up to T c, and they were denoted by short wave (sw), two-dimensional (2D), three-dimensional (3D), and critical (cr) fluctuations. The crossover temperature between 3D and 2D (T 3D–2D) in the mean field region was decreased by increasing the addition of Co0.5Zn0.5Fe2O4 nanoparticles, in accordance with the decrease in T scf with x. The coherence length at 0 K along c-axis ξ c(0), effective layer thickness of the 2D system d, and inter-layer coupling strength J were estimated as a function of Co0.5Zn0.5Fe2O4 nanoparticle addition. Moreover, the thermodynamics, lower and upper critical magnetic fields, as well as critical current density have been calculated from the Ginzburg number N G. it was found that the low concentration of Co0.5Zn0.5Fe2O4 nanoparticles up to x = 0.08 wt% improves the superconducting parameters of Cu0.5Tl0.5-1223 phase. On the contrary, these parameters were deteriorated for (Co0.5Zn0.5Fe2O4) x /Cu0.5Tl0.5-1223 composite with x > 0.08 wt%.

关键词： Co0.5Zn0.5Fe2O4 nanoparticles Cu0.5Tl0.5-1223 phase pseudogap temperature fluctuation conductivity

Electrical and mechanical properties of (Bi, Pb)-2223 substituted by holmium

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Journal of Advanced Ceramics 2016年第1期5卷 54-69页

作者： W.ABDEEN S.MARAHBA R.AWAD a.i.abou aly i.H.iBRAHiM M.MATAR Superconductivity and Metallic Glass Lab Physics Department Faculty of ScienceAlexandria University Alexandria EgyptPhysics Department University College at Al-Gamom Umm Al-Qura University Saudi Arabia Physics Department Faculty of Science Beirut Arab University(BA U) Beirut Lebanon Superconductivity and Metallic Glass Lab Physics Department Faculty of ScienceAlexandria University Alexandria Egypt

The effect of the partial substitution of Ca2+ by Ho3+ ions on the electrical and mechanical properties of the superconducting phase (Bi,Pb)-2223 was studied. Superconducting samples of the type (Bi1.8Pb0.4)Sr2Ca2.1−x Ho x Cu3.1O10+δ were prepared by solid-state reaction technique under ambient pressure, and characterized by means of X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The superconducting transition temperature T c and pseudogap temperature T* were estimated from electrical resistivity measurements, while the critical current density J c was determined from i–V curves. The electrical resistivity data were discussed according to bipolaron model in the absence of thermally excited individual polarons. The sample with x = 0.025 showed the highest phase volume fraction, T c, and J c. Room temperature Vickers microhardness measurements were carried out at different applied loads (0.25–5 N) in order to investigate the performance of the mechanical properties of (Bi1.8Pb0.4)Sr2Ca2.1−x Ho x Cu3.1O10+δ phase. it was found that all the samples exhibit normal indentation size effect (iSE). The Vickers microhardness number H V increased as x increased from 0 to 0.025. The experimental results were discussed in view of Meyer’s law, Hays–Kendall (HK) approach, elastic/plastic deformation (EPD) model, and proportional specimen resistance (PSR) model. The load independent (true) microhardness of (Bi1.8Pb0.4)Sr2Ca2.1−x Ho x Cu3.1O10+δ superconducting samples showed identical behavior to that of the PSR model.

关键词： (Bi,Pb)-2223 phase Ho substitution Vickers microhardness bipolaron model pesudogap temperature

The effect of nanosized CoFe2O4 addition on the magnetic properties of GdBa2Cu3O7-δ using AC magnetic susceptibility measurements

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Journal of Advanced Ceramics 2016年第1期5卷 93-101页

作者： R.AWAD N.H.MOHAMMED a.i.abou aly S.iSBER H.A.MOTAWEH D.EL-SAiD BAKEER M.ROUMi(E) Physics Department Faculty of Science Alexandria University Alexandria EgyptPhysics Department Faculty of Science Beirut Arab University Lebanon Physics Department Faculty of Science Alexandria University Alexandria Egypt Physics Department American University of Beirut Beirut Lebanon Physics Department Faculty of Science Damanhur University Damanhur Egypt Accelerator Laboratory Lebanese Atomic Energy Commission Beirut Lebanon

Superconductor samples of type (CoFe2O4)xGdBa2Cu3O7-δ (0≤x≤0.1) were synthesized by the conventional solid-state reaction technique, whereas nanosized CoFe2O4 was prepared by co-precipitation method with grain size of about 8.5 nm. The elemental content of the prepared samples was determined using particle induced X-ray emission (PiXE). The temperature dependence of real (χ') and imaginary (χʺ) components of AC magnetic susceptibility (ACMS) at different magnetic field amplitude (3–15 Oe) was investigated. The analysis of the temperature dependence of ACMS was performed using Bean critical state model. The values of the critical current density J c at T > T p (T p is the inter-granular loss peak temperature) were calculated as a function of magnetic field and nanosized CoFe2O4 content. it was found that the low nanosized CoFe2O4 addition content (x = 0.01) improves the critical current density J c of Gd-123 superconducting phase. The observed variation of J c with temperature indicated that the weak links are changed from superconductor–normal metal–superconductor (SNS) for free sample to superconductor–insulator–superconductor (SiS) type of junctions for samples added with nanosized CoFe2O4 of x > 0.01. We also discussed the experimental results in the framework of the critical state model to estimate the effective volume fraction of the grains f g using Cole–Cole plots.

关键词： Gd-123 phase nanosized CoFe2O4 AC magnetic susceptibility (ACMS) critical current density particle induced X-ray emission (PiXE)

The effect of multi-intermediate bands on the behavior of an inAs_(1-x)N_x/GaAs(1-y)Sb_y quantum dot solar cell

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Journal of Semiconductors 2015年第4期36卷 1-6页

作者： abou El-Maaty M.aly A.Nasr Power Electronics and Energy Conversion Department ERINRCB College of Computer Qassim University Radiation Engineering Department NCRRTAtomic Energy Authority

A mathematical model of quantum dot intermediate band solar cells （QDiBSCs） is investigated using two intermediate bands （iBs）. These two iBs arise from the quantum dot （QD） semiconductor material within the bandgap energy. Some parameters such as the width of the QD （WQD） and the barrier thickness or the inter-dot distances between the QDs （BT） are studied to show their influence on the performance of the QDiBSC. The timeindependent Schr6dinger equation, which is solved using the Kronig-Penney model, is used to determine the posi- tion and bandwidth energies of the two iBs. in our proposed model, the cubic shape of the QDs from inAs0.9N0.1 and the barrier or host semiconductor material from GaAs0.98Sb0.02 are utilized. it is shown from the results obtained that changing the parameters WQD and Bx has more influence on the bandwidth energy for the first iB, A 1, than in the case of the second iB, A2. The optimum power conversion efficiencies （PCEs） of the QDiBSCs with two iBs for the model under study are 58.01% and 73.55% at 1 sun and maximum solar concentration, respectively. One can observe that, in the case of the two iBs, an improvement of the PCE is achieved.

关键词： intermediate bands solar cells quantum dots efficiency solar concentration

Synthesis, Characterization and Corrosion inhibitive Properties of New Thiazole Based Polyamides Containing Diarylidenecyclohexanone Moiety

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Chinese Journal of Polymer Science 2015年第1期33卷 1-13页

作者： K.i.aly M.A.Hussein Polymer Chemistry Lab. 122 Chemistry Department Faculty of Science Assiut University Assiut 71516 Egypt Chemistry Department Faculty of Science King Abdulaziz UniversityJeddah 21589 Kingdom of Saudi Arabia

The present work aimed to synthesize a new interesting series of thiazole based polyamides containing diarylidenecyclohexanone moiety 5a-5f using low temperature solution polycondensation technique. The new polymers were synthesized by the reaction of thiazole based monomer namely, bis（2-aminothiazol-4-ylbenzylidene）cyclohexanone 3 with different aliphatic and aromatic diacid chlorides using NMP, and in the presence of anhydrous Li Cl as catalyst. Adipoyl, sebacoyl, oxaloyl, terephthaloyl, isophthaloyl dichlorides and biphenyl dicarbonyl dichloride were used as diacid chlorides. The structure of the model compound 4 as well as the new polymers was confirmed by correct elemental and spectral analyses. The thermal properties of those polymers were evaluated by TGA and DTG measurements and correlated to their structural units, beside X-ray diffraction analysis, solubility and viscometry measurements. The inherent viscosities for the synthesized polymers were in the range 0.6–1.03 d L/g. On the other hand the corrosion inhibitive properties of monomer 3 as well as polyamides 5d and 5f as selected examples were carried out on carbon-steel in 0.5 mol/L H2SO4 at 40 °C. The calculated inhibition efficiency（iE%） for polymer 5d was in the range（82 ± 6）% in all selected concentrations. The best value of iE% was obtained at 1 mg/L to reach 98.24% for polymer 5d and at 0.5 mg/L to reach 87.75% for polymer 5f.

关键词： Diarylidenecyclohexanone Polyamides Synthesis Characterization Thiazole Corrosion inhibitive properties.

Synthesis of Novel Quinazoline Derivatives as Antimicrobial Agents

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Chinese Journal of Chemistry 2003年第3期21卷 339-346页

作者： aly，A.A DepartmentofChemistry FacultyofScienceBenhaUniversityBenhaEgypt

Quinazoline isothiocyanate 1 reacts with various nucleophiles (nitrogen nucleophiles, oxygen nucleophiles and sulphur nucleophiles) to afford heterocyclic systemes 2–13. Also, the [4 + 2] cycloaddition reaction of 1 with phenyl isocyanate, benzylidene aryl amine and cinnamic acid derivatives gave novel heterocyclic compounds 14–16. Moreover, the reaction of 1 with active methylene compounds under Michael reaction conditions also was investigated to yield 17 and 18 and it was found that all these reactions proceeded via isothiocyanate heterocyclization to furnish non‐condensed heterocyclic compounds. Some of the newly synthesized compounds were tested for their antimicrobial activities.

关键词： quinazoline congeners quinazoline isothiocyanate antimicrobial activity

Synthesis and Pharmacological Activity of Annelated Pyrimidine Derivatives

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Chinese Journal of Chemistry 2005年第2期23卷 211-217页

作者： aly,A.A.. ChemistryDepartment FacultyofScienceBenhaUniversityBenha-Egypt

A series of 1-glycosyl-2-glycosylthiopyrimidine (4), annelated pyrimidinederivatives, pyrazolo[3,4-d]-pyrimidine (8), ditetrazolo[1,5-a;1′,5′-c]pyrimidine (9),2,9a,10-triazaanthracene (12), thieno[2,3-d]pyrimidine (14), 9-thia-1,3,5,7-tetraazafluorene-8-one(15), 7-oxa-9-thia-1,3,5-triazafluorene-8-one (16), 5-oxa-9-thia-1,3-diaza-fluorene (21a and 21b)derivatives have been synthesized via a sequence of heterocyclization reactions of suitablyfunctionalized6-[5-(4-bromophenyl)oxazol-4-yl]-1,2,3,4-tetrahydro-2-thioxo-4-oxopyrimidine-5-carbonitrile (2) withdifferent electrophiles and nucleophiles. The new compounds were prepared with the objective tostudy their pharmacological properties.

关键词： 2-methylsulfanylpyrimidine thienopyrimidine azafluorenone pharmacologicalproperty

BRCA1,PARP,and 53BP1:conditional synthetic lethality and synthetic viability

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Journal of Molecular Cell Biology 2011年第1期3卷 66-74页

作者： Amal aly Shridar Ganesan Cancer institute of New Jersey Robert Wood Johnson Medical School-UMDNJ195 Little Albany StreetNew BrunswickNJ 08903USA

BRCA1 plays a critical role in the regulation of homologous recombination(HR)-mediated DNA double-strand break ***1-deficient cancers have evolved to tolerate loss of BRCA1 *** renders them vulnerable to agents,such as PARP inhibitors,that are conditionally‘synthetic lethal’with their underlying repair *** studies demonstrate that BRCA1-deficient cells may acquire resistance to these agents by partially correcting their defect in HR-mediated repair,either through reversion mutations in BRCA1 or through‘synthetic viable’loss of *** findings and their clinical implications will be reviewed in this article.

关键词： DNA repair BRCA1 53BP1 PARP

Review of Artificial Neural Networks for Wind Turbine Fatigue Prediction

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Structural Durability & Health Monitoring 2024年第6期18卷 707-737页

作者： Husam AlShannaq aly Mousaad aly Windstorm impact Science and Engineering(WISE)Research LabLouisiana State UniversityBaton RougeLA 70803USA

Wind turbines have emerged as a prominent renewable energy source *** monitoring and detection methods are crucial to enhance their operational effectiveness,particularly in identifying fatigue-related *** review focuses on leveraging artificial neural networks(ANNs)for wind turbine monitoring and fatigue detection,aiming to provide a valuable reference for researchers in this domain and related *** various ANN techniques,including General Regression Neural Network(GRNN),Support Vector Machine(SVM),Cuckoo Search Neural Network(CSNN),Backpropagation Neural Network(BPNN),Particle Swarm Optimization Artificial Neural Network(PSO-ANN),Convolutional Neural Network(CNN),and nonlinear autoregressive networks with exogenous inputs(NARX),we investigate the impact of average wind speed on stress transfer function and fatigue damage in wind turbine *** findings indicate significant precision levels exhibited by GRNN and SVM,making them suitable for practical *** demonstrates superiority over BPNN and PSO-ANN in predicting blade fatigue life,showcasing enhanced accuracy,computational speed,precision,and convergence rate towards the global ***,CNN and NARX models display exceptional accuracy in classification *** results underscore the potential of ANNs in addressing challenges in wind turbine monitoring and fatigue ***,it’s important to acknowledge limitations such as data availability and model *** research should explore integrating real-time data and advanced optimization techniques to improve prediction accuracy and applicability in real-world *** summary,this review contributes to advancing the understanding of ANNs’efficacy in wind turbine monitoring and fatigue detection,offering insights and methodologies that can inform future research and practical applications in renewable energy systems.

关键词： Wind turbine fatigue prediction artificial neural network