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Directional solidification and physical properties measurements of the zinc-aluminum eutectic alloy

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International Journal of Minerals,Metallurgy and Materials 2011年第6期18卷 659-664页

作者： S.Engin U.Byük h.kaya N.Maraslι Department of Physics Institute of Science and TechnologyErciyes University Department of Science Education Faculty of EducationErciyes University Department of Physics Faculty of ScienceErciyes University

Zn-5wt% Al eutectic alloy was directionally solidified with different growth rates （5.32-250.0μm/s） at a constant temperature gradient of 8.50 K/mm using a Bridgman-type growth *** values of eutectic spacing were measured from transverse sections of the *** dependences of the eutectic spacing and undercooling on growth rate are determined as λ=9.21V-0.53 and ΔT=0.0245V0.53,*** results obtained in this work were compared with the Jackson-hunt eutectic theory and the similar experimental results in the *** of directionally solidified samples was also measured by using a microhardness test *** dependency of the microhardness on growth rate is found as hv=***,the electrical resistivity （r） of the casting alloy changes from 40×10-9 to 108×10-9 Ω·m with the temperature rising in the range of 300-630 *** enthalpy of fusion （Δh） and specific heat （Cp） for the Zn-Al eutectic alloy are calculated to be 113.37 J/g and 0.309 J/（g·K）,respectively by means of differential scanning calorimetry （DSC） from heating trace during the transformation from liquid to solid.

关键词： eutectic alloys directional solidification microhardness electrical conductivity enthalpy specific heat

Experimental determination of interfacial energies for Ag_2Al solid solution in the CuAl_2-Ag_2Al system

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Chinese Physics B 2009年第9期18卷 3952-3959页

作者： Ocak Y Akbulut S Keslioglu K Marasl1 N ad1rl1 E kaya h Department of Physics Faculty of Arts and SciencesErciyes University Department of Physics Institute of Science and TechnologyErciyes University Department of Physics Faculty of Arts and SciencesNigde University Department of Science Education Education FacultyErciyes University

The equilibrated grain boundary groove shapes of solid solution Ag2Al in equilibrium with an AI-Cu-Ag liquid were observed from a quenched sample with a radial heat flow apparatus. The Gibbs Thomson coefficient, solid liquid interfacial energy and grain boundary energy of the solid solution Ag2Al have been determined from the observed grain boundary groove shapes. The thermal conductivity of the solid phase and the thermal conductivity ratio of the liquid phase to solid phase for Ag2Al-28.3 at the %CuAl2 alloy at the melting temperature have also been measured with a radial heat flow apparatus and Bridgman type growth apparatus, separately.

关键词： solid-liquid interfaces metals and alloys surface energy thermal conductivity

比较输卵管内移植立即穿刺的卵子和经宫颈宫腔内培养第2～3天的胚胎

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世界核心医学期刊文摘（妇产科学分册） 2006年第10期2卷 35-36页

作者： Ozkaya O. Sezik M. kaya h. 朱晓明 Yayla Mah. 1613 sok. 6/5 32100 Isparta Turkey

Objective: The aim of this study was to assess the outcomes of laparoscopic intrafallopian transfer of injected oocytes rapidly(1 hour at most) after intracytoplasmic sperm injection(rapid ICSI-ZIFT). Materials and Methods: Data on 58 cycles in 58 couples, who underwent rapid ICSI-ZIFT treatment over a 12-month period were retrospectively investigated. The control group included 28 patients, who underwent intrauterine embryo transfer(ET) after ICSI. Following down-regulation with goserelin acetate, step-up ovulation inductionwith recombinant gonadotropins was carried out. After oocyte retrieval and ICSI, a maximum of 4 injected oocytes with intact cytoplasmic membrane and clear cytoplasm were replaced within 1 hour into a unilateral fallopian tube under laparoscopic guidance. Biochemical pregnancy, clinical pregnancy, implantation, miscarriage, and take-home baby rates were our outcome measures. Rapid ICSI-ZIFT and conventional ICSI-ET groups were compared using univariate and multivariate analyses. Results: After controlling for confounding factors by logistic regression, none of the outcome variables were found to be improved with rapid ICSI-ZIFT. Implantation rates were also comparable(17.2%for rapid ICSI-ZIFT and 17.1 %for ICSI-ET) with no significant differences(p=0.9). The multiple pregnancy rate in the ICSI-ZIFT group was exceedingly high(34.8%versus 0%, p=0.07). Con- clusions: Immediate tubal transfer of microinjected oocytes is associated with similar implantation and take-home baby rates compared to rates for intrauterine ET after ICSI. Given the risk of laparoscopy and the unavoidable higher risk of multiple pregnancy, intratubal transfer of injected oocytes seems unsuitable for clinical use.

关键词：活产率降调节临床妊娠治疗周期生化妊娠促性腺激素取卵显微注射卵母细胞促排卵

Application of Adapted-Bubbles to the helmholtz Equation with Large Wavenumbers in 2D

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Numerical Mathematics(Theory,Methods and Applications) 2023年第1期16卷 26-57页

作者： Adem kaya Institut füur Mathematik Universität PotsdamKarl-Liebknecht-Str.24-2514476 Potsdam/GolmGermany

An adapted-bubbles approach which is a modification of the residualfree bubbles(RFB)method,is proposed for the helmholtz problem in 2D.A new two-level finite element method is introduced for the approximations of the bubble *** the other equations such as the advection-diffusion equation,RFB method when applied to the helmholtz equation,does not depend on another stabilized method to obtain approximations to the solutions of the ***-bubbles(AB)are obtained by a simple modification of the *** modification increases the accuracy of the numerical solution *** provide numerical experiments with the AB method up to ch=5 where c is the wavenumber and h is the mesh *** tests show that the AB method is better by far than higher order methods available in the literature.

关键词： helmholtz equation adapted-bubbles residual-free bubbles two-level finite element

Dissolution behavior of Caldag lateritic nickel ore subjected to a sequential organic acid leaching method

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International Journal of Minerals,Metallurgy and Materials 2015年第11期22卷 1131-1140页

作者： Sait Kursunoglu Muammer kaya Department of Mining Engineering Eskisehir Osmangazi University

The dissolution behavior of Caldag lateritic nickel ore subjected to a sequential organic acid leaching method was investigated. The effects of the type of organic acid, acid concentration, leaching time, and leaching temperature on the lateritic nickel ore were examined. Organic acids were used individually prior to sequential leaching. Citric acid was more effective than the other two acids for the selective leaching of nickel and cobalt. An increase in the citric acid concentration negligibly affected the dissolution of the metals, whereas temperature exhibited a strong beneficial effect. Oxalic acid was determined to be the most appropriate organic acid for the second leaching step. After 8 h（4 h ＋ 4 h） of leaching with organic acids（0.5 M citric ＋ 0.5 M oxalic） in sequence at 90°C, 89.63% Ni, 82.89% Co, and 69.63% Fe were leached from the lateritic nickel ore. A sequential citric ＋ oxalic acid leaching method could represent a viable alternative for the dissolution of metals from lateritic nickel ore.

关键词： laterite leaching citric acid oxalic acid dissolution

SYNThESIS,ChARACTERIZATION,ThERMAL DEGRADATION AND ELECTROChEMICAL PROPERTIES OF OLIGO-4-m-TOLYLAZOMEThINEPhENOL

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Chinese Journal of Polymer Science 2006年第6期24卷 647-656页

作者： smet kaya Yasin Bayrakli Department of Chemistry Faculty of Sciences and Artsanakkale Onsekiz Mart UniversityTR-17020 anakkaleTurkey

The oxidative polycondensation reaction conditions of 4-m-tolylazomethinephenol （4-TAMP） in the presence of air O2 and NaOCl as oxidants were studied in an aqueous alkaline medium between 50 and 90℃. The structures of the obtained monomer and oligomer were confirmed by FT-IR, UV-Vis, ^1h- and ^13C-NMR and elemental analysis techniques. The physical characterization was made by TG-DTA, size exclusion chromatography （SEC） and solubility tests. At the optimum reaction conditions, the yield of oligo-4-m-tolylazomethinephenol （O-4-TAMP） was found to be 62.50% （for air O2 oxidant） and 90.0% （for NaOCl oxidant）, respectively. According to the SEC analysis, the number-average molecular weight （Mn）, weight-average molecular weight （Mw） and polydispersity index （PDI） values of O-4-TAMP were found to be 2310, 2610 g tool 1 and 1. 13, respectively, using air O2, and 1390, 1710 g mol^-1 and 1.23, using NaOCl, respectively. According to TG-DTA analyses, O-4-TAMP was more stable than 4-TAMP against thermal decomposition. The weight losses of 4-TAMP and O-4-TAMP were found to be 68% and 58% at 1000℃. Electrical conductivity of the O-4-TAMP was measured, showing that the polymer is a typical semiconductor. Electrochemically, the highest occupied molecular orbital （hOMO）, the lowest unoccupied molecular orbital （LUMO） and electrochemical energy gaps （E＇g） for 4-TAMP are -5.96, -3.22 and 2.74 eV, respectively. The hOMO, LUMO and （E＇g） for O-4-TAMP are -5.78, -3.44 and 2.34 eV, respectively. According to UV-Vis measurements, optical band gaps （Eg） of 4-TAMP and O-4-TAMP were found to be 3.45 and 3. 1 0 eV, respectively.

关键词： Air O2 NaOCl Oligo-4-m-tolylazomethinephenol Oxidative polycondensation Thermal analysis Band gap Conductivity

The removal of Cr(Ⅵ) through polymeric supported liquid membrane by using calix[4]arene as a carrier

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Chinese Journal of Chemical Engineering 2019年第1期27卷 85-91页

作者： Canan Onac Ahmet kaya Duygu Ataman Nefise Ayhan Gunduz h.Korkmaz Alpoguz Department of Chemistry Pamukkale University

In this work, the transport and removal of Cr(Ⅵ) were achieved through supported liquid membrane(SLM) by using a 5,17, di-tert-butyl-11,23-bis[(1,4-dioxa-8-azaspiro [4,5]decanyl)methyl]-25,26,27,28-tetrahydroxy calix[4]arene carrier, dissolved in 2-nitrophenyl octyl ether *** studied parameters are the solvent effect in the membrane phase, the effect of carrier concentration, and the acid type in the donor *** Celgard 2500 was used as a membrane *** used the Danesi mass transfer model to calculate the permeability coefficients for each studied *** addition, AFM and SEM techniques were used to characterize the surface morphology of the prepared Celgard 2500 membrane that included the calix[4]arene carrier.

关键词： Resorcinarene Liquid membrane Cr(Ⅵ) Surface characterization

SYNThESIS, ChARACTERIZATION AND SOME PROPERTIES OF EPOXY RESINS CONTAINING AZOMEThINE BONDING

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Chinese Journal of Polymer Science 2013年第8期31卷 1087-1095页

作者： smet kaya Murat Gül anakkale Onsekiz Mart University Faculty of Sciences and Arts Department of Chemistry Polymer Research Laboratory

New epoxy resins were prepared from hydroxyl substituted Schiff base monomers in two steps. The first step is based on the synthesis of hydroxyl substituted Schiffbase monomers via condensation reaction. The second step includes the reaction between Schiff base monomers with cpichlorohydrine （EPC） to obtain epoxy resins. The structures of resulting compounds were confirmed by FTIR and h-NMR. TG-DTA and DSC measurements were made for thermal characterizations of the compounds. Chemical resistances of the cured epoxy-amine systems in acidic, alkaline and organic solvents were determined for coating applications. hC1 （aqueous solution, 10%）, NaOh （aqueous solution, 10%）, DMSO, DMF, N-methylpyrrolidone, ethanol, ThF and acetone were used for corrosion tests. Chemical resistance data show that the synthesized resins have good chemical resistance against various acid, alkaline and common organic solvents.

关键词： Epoxy resin Thermal analysis Poly(imine)s.

Correlation of work function and stacking fault energy through Kelvin probe force microscopy and nanohardness in diluteα-magnesium

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Journal of Magnesium and Alloys 2024年第1期12卷 237-250页

作者： Yigit Türe Ali Arslan kaya hüseyin Aydin Jiang Peng Servet Turan Eskisehir Technical University Porsuk Vocational SchoolElectronics and Automation DepartmentProgram of MechatronicsEskisehirTurkey Mugla Sitki Kocman University Engineering FacultyMetallurgy and Materials Engineering DepartmentMuglaTurkey hüseying Aydın TUBITAK MRCTurkey Jiang Peng Chongqing UniversityChina Eskisehir Technical University Engineering FacultyMaterials Science and Engineering DepartmentEskisehirTurkey

Electronic interactions of the Group 2A elements with magnesium have been studied through the dilute solid solutions in binary Mg-Ca,Mg-Sr and Mg-Ba *** investigation incorporated the difference in the‘Work Function'(ΔWF)measured via Kelvin Probe Force Microscopy(KPFM),as a property directly affected by interatomic bond types,*** electronic structure,nanoindentation measurements,and Stacking Fault Energy values reported in the *** was shown that the nano-hardness of the solid-solutionα-Mg phase changed in the order of Mg-Ca>Mg-Sr>***,it was shown,by also considering the nano-hardness levels,that SFE of a solid-solution is closely correlated with its‘Work Function'***-hardness measurements on the eutectics andΔWF difference between eutectic phases enabled an assessment of the relative bond strength and the pertinent electronic structures of the eutectics in the three *** withΔWF and at least qualitative verification of those computed SFE values with some experimental measurement techniques were considered important as those computational methods are based on zero Kelvin degree,relatively simple atomic models and a number of *** asserted by this investigation,if the results of measurement techniques can be qualitatively correlated with those of the computational methods,it can be possible to evaluate the electronic structures in alloys,starting from binary systems,going to ternary and then multi-elemental *** investigation has shown that such a qualitative correlation is *** all,the SFE values are not treated as absolute values but rather become essential in comparative investigations when assessing the influences of alloying elements at a fundamental level,that is,free electron density *** study indicated that the principles of‘electronic metallurgy'in developing multi-elemental alloy systems can be followed via practical experimental methods,i.e.ΔWF measurements using KPF

关键词： Mg alloys Dilute alloys Work function Stacking fault energy Kelvin probe force microscopy Short range order Miedema Nanoindentation Eutectics