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Anodization of titanium alloys for orthopedic applications

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Frontiers of Chemical Science and Engineering 2019年第1期13卷 28-45页

作者： Merve Izmir Batur ercan Department of Metallurgical and Materials Engineering Middle East Technical University 06800 Ankara Turkey Biomedical Engineering Program Middle East Technical University 066800 Ankara Turkey

In recent years, nanostructured oxide films on titanium alloy surfaces have gained significant interest due to their electrical, catalytic and biological properties. In literature, there is variety of different approaches to fabricate nanostructured oxide films. Among these methods, anodization technique, which allows fine-tuning of oxide film thickness, feature size, topography and chemistry, is one of the most popular approaches to fabricate nanostructured oxide films on titanium alloys, and it has been widely investigated for orthopedic applications. Briefly, anodization is the growth of a controlled oxide film on a metallic component attached to the anode of an electrochemical cell. This review provides an overview of the anodization technique to grow nanostmctured oxide films on titanium and titanium alloys and summarizes the interactions between anodized titanium alloy surfaces with cells in terms of cellular adhesion, proliferation and differentiation. It will start with summarizing the mechanism of nanofeatured oxide fabrication on titanium alloys and then switch its focus on the latest findings for anodization of titanium alloys, including the use of fluoride free electrolytes and anodization of 3D titanium foams. The review will also highlight areas requiring further research to successfully translate anodized titanium alloys to clinics for orthopedic applications.

关键词： titanium alloys anodization biocompatibility orthopedics

Tm-doped ZnO nanorods as a TCO for PV applications

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Journal of Rare Earths 2018年第10期36卷 1067-1073页

作者： Hakan Colak ercan Karakose Department of Chemistry Faculty of ScienceCankin Karatekin University18100cankinTurkey Kayseri Vocational College Erciyes University38039KayseriTurkey

In photovoltaic（PV） devices, a transparent conducting oxide（TCO） film is used as a transparent electrode which permits sun rays to reach to the photoactive semiconducting layers and also to collect the photogenerated electrons. Due to their electrical and optical properties zinc oxide（ZnO） based thin films and nanostructures are considered as an abundant and safer option for TCOs. In this study, undoped and thulium（Tm）-doped ZnO nanorods（NRs） were produced on glass substrates via spin coating and hydrothermal methods. The ZnO samples were described by X-ray diffractometry（XRD）. Morphological features of the ZnO samples were investigated with scanning electron microscopy（SEM）. It is observed that the all ZnO samples have nanorod shape. The average rods diameter is between 75 and 100 nm. Also,the rods length is found to be between 0.96 and 1.62 μm. Electrical properties of the ZnO samples were performed via four probe method. The conductivity increases with measurement temperature and Tm doping. Optical spectra of the ZnO samples were measured in UV-Vis range and the band gap（Eg） is found to be 3.35 eV.

关键词： Photovoltaics TCO materials ZnO Doping materials Hydrothermal methods Rare earths

Precipitate Formation and Evolution in the Superalloy IN738LC

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稀有金属材料与工程 2009年第A3期38卷 142-146页

作者： Dinc Erdeniz ercan Balikci Bogazici University

IN738LC is a polycrystalline, nickel-based superalloy, which provides a high performance in aggressive environments at temperatures above 650°C. At this high temperature, the expected properties are good corrosion resistance, optimal thermal properties, and creep and fatigue resistance. These required properties are obtained via solid solution hardening and precipitation hardening of a face-centered cubic (fcc) Ni matrix phase. The size, morphology and distribution of precipitates determine the properties of the material. Thus, microstructure control is very important for effective use of IN738LC. In this study, a number of heat treatments were conducted to observe the evolution of precipitates. The formation of bimodal microstructure at 1140°C is explored. The data shows formation of a duplex size precipitate microstructure after 5 min of the aging. Formation mechanism of the duplex structure is discussed. Coarsening and dissolution mechanisms at 1120°C are discussed. Precipitates are found to grow up to a critical size in coherent and cubical morphology, beyond which dissolution sets in.

关键词：镍基合金耐腐蚀性沉淀物复合材料

Construction of a Quadratic Model for Predicted and Measured Global Solar Radiation in Chile

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Chinese Physics Letters 2007年第1期24卷 291-293页

作者： ercan YILMAZ Beatriz CANCINO Edmundo LOPEZ Department of Physics Mustafa Kemal University 31040 Antakya Turkey Department of Food Engineering Pontificia Universidad Catdlica de Valparaiso Chile Department of Electrical Engineering Pontificia Universidad Cat61ica de Valparaiso Chile

Global solar radiation data for sites in Chile are analysed and presented in a form suitable for their use in engineering. A new model for monthly average data is developed to predict monthly average global radiation with acceptable accuracy by using actinographic data due to scarcing of pyranometer data. Use of the new quadratic model is proposed because of its relatively wider spectrum of values for Angstrom coefficients ao, al, and a2.

关键词： Quadratic Model Global Solar Radiation Chile engineering

Effects of thinning on stand structure and tree stability in an afforested oriental beech(Fagus orientalis Lipsky) stand in northeast Turkey

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Journal of Forestry Research 2015年第1期26卷 123-129页

作者： Zafer Yücesan Sevilay ?z?elik ercan Oktan Faculty of Forestry Karadeniz Technical University General Directorate of Combating to Desertification and Erosion Control

We studied relationships between stand structure and stand stability according to thinning intensity in an afforested oriental beech stand. Various thinning intensities were applied in sample stands. We sampled eight plots in stands that were lightly thinned, eight plots in heavily thinned stands and eight plots in unthinned stands as a control. Height and diameter distributions of the stands were measured to assess stand structure. We quantified individual tree stability and collective stability. Heavy thinning during the first thinning operation damaged the storied structure of the stand in thicket stage and affected collective structuring ability. While most control plots had multi-storied stands, after light and heavy thinning two-storied structure became more *** gaps occurred in the canopy after heavy thinning. On average, nine tree collectives were formed per sampling plot in the untreated stand, seven collectives after thinning in 2008 and four collectives after thinning in 2009. Stable trees accounted for 17 % of trees in control plots, 24 % in lightly thinned plots, and 15 % in heavily thinned plots. Collective stability values were 83 % in control plots, 82 % in lightly thinned plots and 36 % in heavily thinned plots. We conclude that it is necessary to retain collective structuring capacity during thinning operations for sustaining stand stability.

关键词： Oriental beech Thinning Stand structure Tree stability

Mechanical Properties of Reactive Powder Concretes Produced Using Pumice Powder

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Journal of Wuhan University of Technology(Materials Science) 2019年第2期34卷 353-360页

作者： Abdurrezzak BAKIS ercan ISIK Alev Ak?ll? EL Mustafa üLKER Bitlis Eren University Faculty of Engineering and Architecture Department of Civil Engineering Bitlis Eren University Vocational School of Technical Sciences

We examined the applicability of the pumice aggregate on the concrete formed by considering the reactive powder concrete mixture ratios, for the rigid superstructure concrete road pavement and building construction. The natural pumice aggregate in fibrous and non-fibrous concrete samples was used in the production of concrete by fracturing in 0.1-0.6 mm dimensions in rotor mill. The concreted formed in this way is named after the pumice powder concrete(PPC). The PPC samples produced were taken 7 days as 20 ℃ standard water cure, 28 days as 20 ℃ standard cure and 9 different types of combined cures. The combined cures were applied different temperatures in different durations. PPC samples were subjected to some pressure and flexural tests at the end of the standard water and combined cures. The highest compressive and flexural strengths of PPC samples were obtained after the combined cures: 3 days in 20 ℃ as standard water curing + 2 days in 180 ℃ in drying-oven. The highest compressive strength of PPC samples without any fiber was found to be 47.27 MPa, as for the highest flexural strength, it is found to be 5.23 MPa, in the end of the study. The highest compressive strength of fibrous PPC samples was 51.12 MPa, while flexural strength was 6.57 MPa.

关键词： reactive powder concrete (RPC) pumice powder concrete (PPC) combined cure compressive strength flexural strength

A rare complication of a malleable penile prosthesis： migration to the thigh region

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Asian Journal of Andrology 2013年第6期15卷 852-853页

作者： ercan Ogreden Bayram Güner Erdal Benli Department of Urology Giresun Ada Hospital Giresun 28100 Turkey Department of Urology Ordu University Ordu 52000 Turkey

Dear editor, Here, we discuss an unusual prosthesis migration to the thigh region. Because the incidence of erectile dysfunction increases in par-allel with the prevalence of neurological, degenerative and vascular diseases among elderly men, the use of penile prostheses is common in this age group. Still, cylinder migration following the implantation of a malleable penile prosthesis is a very rare entity.

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Comparative study on corrosion behaviors of Mg-Al-Zn alloys

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Transactions of Nonferrous Metals Society of China 2018年第4期28卷 642-650页

作者： Sennur CANDAN ercan CANDAN Department of Mechanical and Manufacturing Engineering Bilecik Seyh Edebali University

A comparative study on corrosion behaviors of various Mg-Al-Zn alloys(AZ21,AZ41,AZ61 and AZ91 series,cast under same cooling conditions and controlled alloying composition)was carried *** electron microscopy(SEM)and X-ray diffraction(XRD)were used for microstructural *** corrosion behaviors were evaluated by immersion tests and potentiodynamic polarization measurements in 3.5%NaCl *** results showed that the influence of Al addition on corrosion resistance was more pronounced up to 4%(***41)above which its influence was at less *** deterioration of the corrosion resistance of the alloys,at higher Al contents,was attributed to the amount and morphology ofβ-Mg17Al12 intermetallics and the interruption of continuity of the oxide film on the surface of the alloys owing to coarsenedβintermetallics.

关键词： Mg alloy AZ series alloys casting corrosion

AC susceptibility and FC-ZFC magnetic properties of SrTb_(x)Fe_(12-x)O_(19) and SrTm_(x)Fe_(12-x)O_(19) hexaferrites:a comparative study

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Journal of Rare Earths 2021年第8期39卷 1003-1009页

作者： Y.Slimani M.A.Almessiere A.Demir Korkmaz A.Baykal I.ercan Department of Biophysics Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityP.0.Box 198231441 DammamSaudi Arabia Department of Chemistry Istanbul Medeniyet University34700 UskudarIstanbulTurkey Department of Nanomedicine Research Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityP.O.Box 198231441 DammamSaudi Arabia

In this comparative study,Tb and Tm substituted Sr-hexafe rrites(HFs) with the chemical compositions of SrTb_(x)Fe_(12-x)O_(19) and SrTm_(x)Fe_(12-x)O_(19)(x=0.00,0.02 and 0.04) were fabricated via citrate sol-gel *** AC susceptibility and FC-ZFC magnetization were *** product structure and morphologies were also investigated via XRD,TEM and SEM along with *** of temperature dependence of magnetization M-T and AC magnetic susceptibility versus temperature were carried *** various synthesized HFs displayed ferrimagnetic behavior within 10-325 *** lower temperatures,super-spin glass-like behavior was ***-Arrhenius and Vogel-Fulcher models were employed to explore the experimental data of AC susceptibility.

关键词： M-type hexaferrites Magnetic properties AC susceptibility FC/ZFC Rare earths