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High Voltage 2022年第2期7卷 279-287页

作者： Mehmet Murat Ispirli özcan kalenderli Florian Seifert Michael Rock Bülent Oral Group for Lightning and Surge Protection Technische Universität IlmenauIlmenauGermany Electrical Engineering Department Istanbul Technical UniversityIstanbulTurkey Research Unit High‐Voltage Technologies Technische Universität IlmenauIlmenauGermany Electrical‐Electronic Engineering Department Marmara UniversityIstanbulTurkey

The valve side of the converter in the high‐voltage direct current is subjected to mixed voltages such as composite AC&DC *** this study,the effects of the homo-geneity of electric field on breakdown voltage were investigated for different�DC component amplitudes of the composite *** field efficiency factor was calcu-lated using mean and maximum field strengths for all of *** of breakdown voltage of air was examined under the composite AC&DC voltage for different ratios�*** one result of the study,the breakdown occurs at the positive half‐wave of the AC voltage despite−DC voltage being applied due to positive corona discharge *** breakdown point is named as the polarity change *** breakdown voltage increases with the decrease of DC voltage component up to polarity change point in non‐uniform electric *** less uniform electric field,the AC breakdown voltage was measured slightly higher than the DC breakdown *** less uniform electric field,as the ratio of the applied AC voltage to DC voltage increases,the breakdown voltage gradually approaches the AC breakdown *** result is similar to the result ob-tained for the+DC component in non‐uniform electric field experiments.

关键词： breakdown composite component

SYNTHESIS,CHARACTERIZATION AND SELECTIVITY STUDIES OF POLY(ACRYLAMIDE) INCORPORATING SCHIFF BASES

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Chinese Journal of Polymer Science 2009年第5期27卷 675-683页

作者： Nursen Sari Serkan zcan Department of Chemistry Faculty of ScienceGazi University

Three novel polymers incorporating Schiff bases,derived from condensation reactions of poly(acrylamide) with 5- chloro-2-hydroxybenzaldehyde,5-bromo-2-hydroxybenzaldehyde and 5-methyl-2-hydroxybenzaldehyde,have been synthesized,and their Cu(Ⅱ) and Ni(Ⅱ) complexes have been *** ~1H-NMR signals of the—CH=N—and—NH_2 groups have been utilized to determine the relative abundances of Schiff base and acrylamide groups in the polymers containing Schiff ***(acrylamide) incorporating Schiff bases and ...

关键词： Selectivity Incorporating Schiff bases Conductivity.

Design and simulation of a 1-GWp solar photovoltaic power station in Sudan

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Clean Energy 2021年第1期5卷 57-78页

作者： Sohaib Nasr Mohamed Abdalla HakanÖzcan Department of Mechanical Engineering Ondokuz Mayis UniversitesiSamsun 55139Turkey

Developing nations have a critical need to increase electricity *** has much unrealized potential for generating solar energy,particularly in the northern *** research study focuses on designing a 1-GW solar power station in northern Sudan using the PVsyst7.0 software *** determine the appropriate location for the solar-energy station,14 criteria were *** process is generic and suitable for use in any other *** method for conducting cash-flow estimates and return on investment is illustrated in the economic *** city of Dongola,the capital of the northern state,was selected because of its high annual irradiance on a horizontal surface at~2333.2 kWh/*** simulation results show that the annual optimum tilt angle of inclination for photovoltaic(PV)modules is 30°,the energy production is 1979259 MWh/yr and the average annual performance rate is *** addition,the electric power consumption per capita in Sudan is 269 kWh/yr,so the proposed solar power plant with 1979259 MWh/yr can provide energy to 7.4 million people per year annually and reduce carbon emissions by~18 million tons of carbon dioxide per *** calculations show that the levelized cost of electricity(LCOE)is$0.06/kWh,the discounted payback period is~11 years and the net present value is$*** a result,the proposed grid-connected PV solar plant is considered economically,technically and environmentally feasible in Sudan.

关键词： solar energy Sudan design simulation evaluation analytic hierarchy process photovoltaic

Automated diagnosis and staging of Fuchs’endothelial cell corneal dystrophy using deep learning

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Eye and Vision 2020年第2期7卷 423-433页

作者： Taher Eleiwa Amr Elsawy EyüpÖzcan Mohamed Abou Shousha Bascom Palmer Eye Institute Miller School of MedicineUniversity of MiamiMiamiFlorida 33136USA Department of Ophthalmology Faculty of MedicineBenha UniversityBenhaEgypt Electrical and Computer Engineering University of MiamiCoral GablesFloridaUSA Net Eye Medical Center GaziantepTurkey Biomedical Engineering University of MiamiCoral GablesFloridaUSA

Background:To describe the diagnostic performance of a deep learning algorithm in discriminating early-stage Fuchs’endothelial corneal dystrophy(FECD)without clinically evident corneal edema from healthy and late-stage FECD eyes using high-definition optical coherence tomography(HD-OCT).Methods:In this observational case-control study,104 eyes(53 FECD eyes and 51 healthy controls)received HDOCT imaging(Envisu R2210,Bioptigen,Buffalo Grove,IL,USA)using a 6 mm radial scan pattern centered on the corneal *** was clinically categorized into early(without corneal edema)and late-stage(with corneal edema).A total of 18,720 anterior segment optical coherence tomography(AS-OCT)images(9180 healthy;5400 early-stage FECD;4140 late-stage FECD)of 104 eyes(81 patients)were used to develop and validate a deep learning classification network to differentiate early-stage FECD eyes from healthy eyes and those with clinical *** 5-fold cross-validation on the dataset containing 11,340 OCT images(63 eyes),the network was trained with 80%of these images(3420 healthy;3060 early-stage FECD;2700 late-stage FECD),then tested with 20%(720 healthy;720 early-stage FECD;720 late-stage FECD).Thereafter,a final model was trained with the entire dataset consisting the 11,340 images and validated with a remaining 7380 images of unseen AS-OCT scans of 41 eyes(5040 healthy;1620 early-stage FECD 720 late-stage FECD).Visualization of learned features was done,and area under curve(AUC),specificity,and sensitivity of the prediction outputs for healthy,early and late-stage FECD were ***:The final model achieved an AUC of 0.997±0.005 with 91%sensitivity and 97%specificity in detecting early-FECD;an AUC of 0.974±0.005 with a specificity of 92%and a sensitivity up to 100%in detecting late-stage FECD;and an AUC of 0.998±0.001 with a specificity 98%and a sensitivity of 99%in discriminating healthy corneas from all ***:Deep learning algorithm is an accurate autonomous nove

关键词： Optical coherence tomography Descemet’s membrane Corneal endothelium Fuchs endothelial dystrophy

半胱氨酸在碳钢与硫酸界面的缓蚀行为(英文)

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物理化学学报 2008年第8期24卷 1387-1392页

作者： zcan Muzaffer KARADA■ Faruk DEHRI lyas Department of Science and Technology Education Cukurova University Department of Physics Cukurova University Department of Chemistry Cukurova University Department of Chemistry Korkut Ata University Osmaniye 80000 Turkey

Interfacial behavior of cysteine (Cys) between mild steel and sulfuric acid solution as a corrosion inhibitor has been studied with electrochemical AC (alternating current) and DC (direct current) techniques at (25.0±0.1) ℃. The AC impedance results were evaluated using equivalent circuits in which a constant phase element (CPE) has been replaced with double layer capacitance (Cdl) to represent the frequency distribution of experimental data. Changes in impedance parameters (charge transfer resistance and double layer capacitance) indicated that cysteine molecules acted by accumulating at the metal/solution interface. The fractional coverage of the metal surface (θ) was determined using AC impedance results and it was found that the adsorption of cysteine on the mild steel surface followed a Langmuir isotherm model with a standard free energy of adsorption (△G0 ads) of -35.1 kJ·mol-1. To clarify the type of interaction between mild steel surface and cysteine molecules with a molecular orbital approach, electronic properties, such as, the highest occupied molecular orbital (HOMO) energy, the lowest unoccupied molecular orbital (LUMO) energy, and the frontier molecular orbital coefficients have been calculated. Energy gaps for the interaction of mild steel surface and cysteine molecules (ELUMO Fe-EHOMO Cys and ELUMO Cys-EHOMO Fe) were used to determine whether cysteine molecules acted as electron donors or electron acceptors when they interacted with the mild steel surface. The local reactivity was evaluated through the condensed Fukui indices. Theoretical calculations were carried out using the density functional theory (DFT) at B3LYP level with the 6-311++G(d,p) basis set for all atoms by Gaussian 03W program.

关键词：软钢防腐技术缓蚀剂半胱氨酸硫磺酸

New combination in Veronica (Scrophulariaceae s.l.) based on morphological characters and the seed storage protein polymorphism

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Journal of Systematics and Evolution 2009年第2期47卷 168-172页

作者： Cem VURAL Servet zcan Mikail AKBULUT Faculty of Arts and Sciences Department of BiologyErciyes University

Veronica erciyasdagi(***) *** comb.& ***.,previously regarded as a variety,is proposed as a new combination,based on the morphological characters and seed storage protein polymorphism presented in this *** addition,information about the ecology and conservation status of Veronica erciyas-dagi was *** taxon is endemic to central Anatolia,Turkey and is critically endangered.

关键词： critically endangered plant morphology Scrophulariaceae seed storage protein polymorphism Veronica erciyasdagi

Prognostic Value of Neutrophil to Lymphocyte Ratio in Acute Myeloid Leukemia

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Open Journal of Internal Medicine 2023年第3期13卷 131-138页

作者： Seda Yilmaz Özcan Çeneli Department of Internal Medicine Clinic of Hematology Konya City Hospital Konya Turkey Department of Hematology Necmettin Erbakan University Konya Turkey

Objective: Acute myeloid leukemia (AML) is a heterogeneous, hematologic malignancy at which short survival may be seen. Our study aims to evaluate the effect of the neutrophil-to-lymphocyte ratio (NLR) on the course of the disease, response to therapy, and overall survival (OS). Materials and Methods: A total of 124 patients followed-up with the diagnosis of AML from 2016 to 2019 were retrospectively examined. Results: 69 of the cases (55.6%) were men and 55 (44.3%) were women. The average age at the time of diagnosis was 53.44 ± 30.3 years old. We determined the NLR as median 0.46 (0.16 - 1.1). In AML, 69 patients were responsive to the induction regimen (57.9%) while 46 patients were unresponsive (37.8%). 5 patients died before completing the regimen. D-dimer was found to be higher and fibrinogen was found to be lower in the responsive group. Lower OS was observed in cases of >60 years of age, male gender, non-APL AML, high NLR, and recurrence at diagnosis. Recurrences were detected in 23 patients (18.5%) and the median time to the recurrence was 416 (236 - 639) days. Fibrinogen level and the bone marrow blast ratio at the time of application were determined to be associated with recurrence. The median follow-up time was 856 (143 - 1276) days. Final condition analysis reveals that 74 patients (59.6%) are alive. Conclusion: We determined in our study that the NLR is effective on survival. Medical literature on this subject is scanty and prospective studies with large patient groups are needed.

关键词： Acute Myeloid Leukemia Neutrophil to Lymphocyte Ratio Prognosis Survival

Prenatal Diagnosis of an Apically Located Congenital Left Ventricular Aneurysm: A Rare Case

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Congenital Heart Disease 2024年第1期19卷 123-129页

作者： Yücel Kaya And Yavuz Hasan Berkan Sayal Büşra Tsakir Gökalp Kabacaoğlu Kadriye NilayÖzcan Department of Perinatology Antalya Education and Research HospitalUniversity of Health SciencesAntalyaTurkey Department of Perinatology Faculty of MedicineSüleyman Demirel UniversityIspartaTurkey

Congenital ventricular aneurysm is a very rare cardiac anomaly.A diagnosis can be made during the prenatal period using fetal *** study presents a very rare apically located left ventricular aneurysm case,and the relevant literature was reviewed and *** this case,a 35-year-old,gravida 2,parity 1 preg-nant woman at 24 weeks of gestation,displayed a wide aneurysmal image in the left ventricular apical wall on fetal *** was a 1.79 mm muscular ventricular septal defect at the apical region of the interven-tricular *** the course of the color Doppler ultrasonography examination,an aberrantﬁbrous band within the left ventricle and consequent turbulentﬂow during systole were *** baby,born via cesarean section at 37 weeks of gestation,is now in its postnatal seventh ***,during echocardiographic follow-ups,changes have been observed,including mild to moderate mitral insufﬁciency and a decrease in systolic *** theseﬁndings,the clinical condition remains *** is of great importance to use a multidis-ciplinary approach in managing these rare cases that could lead to potential adverse outcomes during the antena-tal or postnatal periods.

关键词： Heart aneurysm prenatal diagnosis echocardiography congenital heart defects left ventricle

Effect of a cervical collar on optic nerve sheath diameter in trauma patients

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World Journal of Emergency Medicine 2024年第2期15卷 126-130页

作者： Mümin Murat Yazici Ozcan Yavasi Department of Emergency Medicine Recep Tayyip Erdogan University Training and Research HospitalRize 53020Türkiye

BACKGROUND:As advocated in advanced trauma life support and prehospital trauma life support protocols,cervical immobilization is applied until cervical spine injury is *** study aimed to show the difference in optic nerve sheath diameter(ONSD)between patients with and without a cervical collar using computed tomography(CT).METHODS:This was a single-center,retrospective study examining trauma patients who presented to the emergency department between January 1,2021,and December 31,*** ONSD on brain CT of the trauma patients was measured and analyzed to determine whether there was a difference between the ONSD with and without the cervical ***:The study population consisted of 169 *** CT imaging of patients with(n=66)and without(n=103)cervical collars,the mean ONSD in the axial plane were 5.43±0.50 mm and 5.04±0.46 mm respectively for the right eye and 5.50±0.52 mm and 5.11±0.46 mm respectively for the left *** results revealed an association between the presence of a cervical collar and the mean ONSD,which was statistically significant(P<0.001)for both the right and left ***:A cervical collar may be associated with increased *** effect of this increase in the ONSD on clinical outcomes needs to be investigated,and the actual need for cervical collar in the emergency department should be evaluated on a case-by-case basis.

关键词： Optic nerve sheath diameter Computed tomography Trauma Emergency medicine

Effect of colouring green stage zirconia on the adhesion of veneering ceramics with different thermal expansion coefficients

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International Journal of Oral Science 2013年第4期5卷 236-241页

作者： Guliz Aktas Erdal Sahin Pekka Vallittu Mutlu zcan Lippo Lassila Department of Prosthodontics Faculty of DentistryHacettepe University Department of Biomaterials Science and Turku Clinical Biomaterials Centre University of Turku Dental Materials Unit Center for Dental and Oral MedicineClinic for Fixed and Removable Prosthodontics and Dental Materials ScienceUniversity of Zrich

This study evaluated the adhesion of zirconia core ceramics with their corresponding veneering ceramics, having different thermal expansion coefficients （TECs）, when zirconia ceramics were coloured at green stage. Zirconia blocks （N=240; 6 mm x 7 mm x 7 mm） were manufactured from two materials namely, ICE Zirconia （Group 1） and Prettau Zirconia （Group 2）. In their green stage, they were randomly divided into two groups. Half of the specimens were coloured with colouring liquid （shade A2）, Three different veneering ceramics with different TEC （ICE Ceramic, GC Initial Zr and IPS *** Ceram） were fired on both coloured and non-coloured zirconia cores. Specimens of high noble alloys （Esteticor Plus） veneered with ceramic （VM 13）（n= 16） acted as the control group. Core-veneer interface of the specimens were subjected to shear force in the Universal Testing Machine （0.5 mm-min-1）. Neither the zirconia core material （P=0.318） nor colouring （P=0.188） significantly affected the results （three-way analysis of variance, Tukey＇s test）. But the results were significantly affected by the veneering ceramic （P=0.000）. Control group exhibited significantly higher mean bond strength values （45.7__.8） MPa than all other tested groups （（27.1__.4.1）-（39.7__.4.7） and （27.4__.5.6）-（35.9___4.7） MPa with and without colouring, respectively）（P^0.001）. While in zirconia-veneer test groups, predominantly mixed type of failures were observed with the veneering ceramic covering ~ 1/3 of the substrate surface, in the metal-ceramic group, veneering ceramic was left adhered 1/3 of the metal surface. Colouring zirconia did not impair adhesion of veneering ceramic, but veneering ceramic had a significant influence on the core-veneer adhesion. Metal-ceramic adhesion was more reliable than all zirconia-veneer ceramics tested.

关键词： adhesion bond strength colouring~ thermal expansion coefficient zirconia