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Late Pleistocene Calcretes from Central Anatolia(Lakes Eymir and Mogan, G?lba?? Basin): Comparison to Quaternary Calcretes from Turkey

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Journal of Earth Science 2016年第5期27卷 874-882页

作者： ceren Kücükuysal Mugla Sitki Kocman University Engineering Faculty Department of Geological Engineering Kotekli 48000 Turkey

This study is the first to report the radiocarbon ages, mineralogical, morphological, geochemical and stable isotope compositions of calcretes from Neogene sediments around lakes Eymir and Mogan in the G？lba？？ Basin of Central Anatolia. Morphologically different forms of calcretes in the G？lba？？ Basin include powdery, nodular, fracture infill, laminar and hardpan types. Calcite is the dominant mineral of calcrete compositions; the diagnostic features of dessication cracks, random fractures, Mn O linings and dense sparitic infillings are observed. Chemical analyses show arid conditions with mean annual precipitation of 〈50 mm. δ13C compositions of the calcretes range from-6.77‰ to-9.32‰ PDB, typical for most pedogenic calcretes, reflecting the development under seasonally arid climates and C3-dominated vegetation cover. δ18O values are between-5.57‰ and-7.80‰ PDB, indicating the formation from meteoric water in a vadose zone environment. The results suggest that the Middle Pleistocene was arider and warmer, favouring the formation of palygorskite in association with the different forms of calcrete occurrences, whereas the Late Pleistocene was dryer and cooler, supporting the development of calcretes.

关键词： calcrete micromorphology stable isotopes mineralogy Central Anatolia.

Burkholderia cepacia outbreak in immunocompetent children in a tertiary hospital in Turkey:A case series

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Asian Pacific Journal of Tropical Medicine 2022年第8期15卷 374-378页

作者： ceren Cetin Ugurgul Arslan Department of Pediatric Infectious Diseases University of Health SciencesKartal Dr Lutfi Kardar City HospitalIstanbulTurkey Department of Microbiology University of Health SciencesKocaeli Derince Training and Research HospitalKocaeliTurkey

Objective:To report an outbreak of Burkholderia(B.)cepacia related to contaminated surface cleaner in the pediatric ward of a tertiary hospital in ***:This study retrospectively reported the outbreak occurred between January 16,2018 and January 23,*** immunocompetent patients who developed a bloodstream infection a few days after the hospitalization and who were positive for *** were *** samples were collected from various areas in the hospital to find the source of the ***:All patients had clinical and biochemical evidence of *** of the patients had an underlying disease or had a central venous catheter as a risk *** was isolated from the samples taken from the surface *** antibiotic susceptibilities of *** isolates were identical in the surface cleaners with the isolates from the patients’blood *** outbreak was controlled after removing the surface cleaners from *** of the infected patients died during the ***:Nosocomial *** outbreak may occur in immunocompetent children as *** identification of the outbreak,defining the source and taking appropriate measures to control the outbreak are the key points in the management.

关键词： Burkholderia cepacia Bacteremia Immunocompetent Outbreak Infection control

Detection of critical road roughness sections by trend analysis and investigation of driver speed interaction

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Frontiers of Structural and Civil Engineering 2022年第4期16卷 515-532页

作者： Meltem SAPLIOGLU Ayse unal Melek BOCEK Department of Civil Engineering Suleyman Demirel UniversityIsparta 32260Turkey Department of Civil Engineering Siirt UniversitySiirt 56100Turkey

Pavement roughness(IRI—International Roughness Index values)influence the stability of traffic movements both on intercity roads and urban *** study is to determine the exact locations of critical pavement roughness values that affect traffic motion stability and comfort in city centre highway *** data with 10 m intervals were collected on a 3140 m divided road containing three consecutive signalized intersections in the city centre *** data were analysed using the distance-dependent Mann-Kendall trend analysis method and checkerboard *** sections where roughness is important were determined at a 95%confidence *** results will show where future pavement improvements should be prioritized for municipalities and road maintenance engineers and will form a basis for the urban road management system.

关键词： trend analysis checkerboard model IRI driver speed

Comprehensive analysis of pulsed plasma nitriding preconditions on the fatigue behavior of AISI 304 austenitic stainless steel

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International Journal of Minerals,Metallurgy and Materials 2021年第4期28卷 657-664页

作者： Okan unal Erfan Maleki Remzi Varol Mechanical Engineering Department Karabuk UniversityKarabuk 78050Turkey Modern Surface Engineering Laboratory(MSELAB) Karabuk UniversityKarabuk 78050Turkey Mechanical Engineering Department Sharif University of Technology-International CampusKish Island 79417-76655Iran Mechanical Engineering Department Suleyman Demirel UniversityIsparta 32200Turkey

This study aims to draw an exact boundary for microstructural and mechanical behaviors in terms of pulsed plasma nitriding *** pulsed plasma nitriding treatment was applied to AISI 304 austenitic stainless steel at different temperatures and *** reveal that nitriding depth increased as process temperature and duration *** nitriding depth remarkably increased at 475℃for 8 h and at 550℃for 4 *** austenite structure was transformed into a metastable nitrogen-oversaturated body-centered tetragonal expanded austenite(S-phase)during low-temperature plasma *** S-phase was converted to CrN precipitation at 475℃for 8 h and at 550℃for 4 *** hardness and fatigue limit increased through plasma nitriding regardless of process *** best surface hardness and fatigue limit were obtained at 550℃for 4 h because of the occurrence of CrN precipitation.

关键词： pulsed plasma nitriding S-phase fatigue nitrided layer

Optical coherence tomography angiography of the peripapillary region and macula in normal,primary open angle glaucoma,pseudoexfoliation glaucoma and ocular hypertension eyes

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International Journal of Ophthalmology(English edition) 2020年第5期13卷 744-754页

作者： Helin ceren Kose Oya Tekeli Department of Ophthalmology Ankara University Faculty of MedicineAnkara 06620Turkey

AIM:To evaluate and compare the peripapillary and retinal vasculature changes in primary open angle glaucoma(POAG),pseudoexfoliation glaucoma(PXG),ocular hypertension(OHT)and normal eyes using optical coherence tomography angiography(OCTA).METHODS:A total of 114 POAG,PXG and OHT eyes of 60 patients and 46 eyes of 23 healthy control participants with good quality OCTA images were *** PXG,POAG,OHT,and control groups(aged 68.17±6.30 y,61.11±10.26 y,58.1±8.9 y,and 56.9±4.6 y,respectively)contained of 46,36,32,and 46 eyes,*** of vessel density(VD)in the peripapillary region and macula,average retinal inner thickness,and retinal nerve fiber layer thickness(RNFLT)were compared among *** order to test the accuracy of differentiation between eyes with and without glaucoma,the area was calculated under the receiver operating characteristic(ROC)***:The VD in glaucomatous eyes was significantly lower than the control group in all peripapillary sectors(44.35%±6.78%vs 50.47%±1.83%,P<0.001),the superficial(44.08%±5.46%vs 51.28%±2.85%,P<0.001)and the deep(45.13%±8.55%vs 54.20%±5.44%,P<0.001)vascular *** was a significant difference in peripapillary VD between glaucomatous and OHT eyes(44.35%±6.78%vs 49.86%±2.45%,P<0.001).The OHT group featured a lower superficial(48.06%±4.32%vs 51.28%±2.85%,P=0.027)and deep plexus(48.70%±5.99%vs 54.20%±5.44%,P=0.013)whole image vessel density(wiVD)than did the control *** average macular superficial plexus wiVD was significantly lower in eyes with PXG than in eyes with POAG(42.22%±5.36%vs 46.54%±5.56%,P=0.046).CONCLUSION:OCTA can measure reduced peripapillary and macular VD in eyes with glaucoma and OHT,and these results are correlated to functional and structural glaucomatous *** and macular superficial plexus VD is lower in eyes with PXG than in eyes with ***,the OHT eyes demonstrate impaired macular vasculature in both superficial and deep plexus.

关键词： glaucoma optical coherence tomography angiography vessel density ocular hyper tension pseudoexfoliation glaucoma

Synthesis, characterization and radioluminescence properties of erbium-doped yttria phosphors

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International Journal of Minerals,Metallurgy and Materials 2021年第12期28卷 1983-1990页

作者： Fatma unal Faruk Kaya Kursat Kazmanli Metallurgical and Materials Engineering Department Hitit UniversityCorum 19030Turkey Metallurgical and Materials Engineering Department Istanbul Technical UniversityMaslakIstanbul 34469Turkey

Radioluminescence(RL)behaviour of erbium-doped yttria nanoparticles(Y2O_(3):Er^(3+)NPs)which were produced by sol-gel method was reported for future scintillator *** with dopant rates of 1 at%,5 at%,10 at%and 20 at%Er were produced and calcined at 800℃,and effect of increased calcination temperature(1100℃)on the RL behaviour was also reported.X-ray diffraction(XRD)results showed that all phosphors had the cubic Y2O_(3) bixbyite-type *** lattice parameters,crystallite sizes(CS),and lattice strain values were calculated by Cohen-Wagner(C-W)and Williamson-Hall(W-H)methods,***,the optimum solubility value of the Er^(3+)dopant ion in the Y2O_(3) host lattice was calculated to be approximately 4 at%according to Vegard’s law,which was experimentally obtained from the 5 at%Er^(3+)ion containing *** peak shifts in XRD patterns and X-ray photoelectron spectroscopy(XPS)analyses confirmed that Er^(3+)dopant ions were successfully incorporated into the Y2O_(3) host ***-resolution transmission electron microscopy(HRTEM)results verified the average CS values and agglomerated NPs morphologies were *** electron microscopy(SEM)results showed the neck formation between the particles due to increased calcination *** a result of the RL measurements under a Cu KαX-ray radiation(wavelength,λ=0.154 nm)source with 50 kV and 10 mA beam current,it was determined that the highest RL emission belonged to 5 at%Er doped *** the RL emission spectrum,the emission peaks were observed in the wavelength ranges of 510-575 nm(2H11/2,4S3/2-4I15/2;green emission)and 645-690 nm(4F9/2-4I15/2;red emission).The emission peaks at 581,583,587,593,601,611 and 632 nm wavelengths were also *** was found that both dopant rate and calcination temperature affected the RL emission *** color shifted from red to green with increasing calcination temperature which was attributed to the increased crystallinit

关键词： structure. temperature. solution.

Effect of surfactant on the dielectric and electrorheological properties of zinc borate/silicone oil dispersions

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International Journal of Minerals,Metallurgy and Materials 2019年第12期26卷 1523-1530页

作者： Omer Yunus Gumus Halil Ibrahim unal Bursa Technical University Engineering and Natural Sciences FacultyFiber and Polymer Engineering DepartmentBursa 16310Turkey Gazi University Science FacultyChemistry DepartmentSmart Materials Research Lab.Ankara 06500Turkey

Zinc borate(ZB)particles dispersed in silicone oil(SO)at concentrations of φ=5vol%-20vol% were subjected to dielectric analysis to elucidate their polarization strength,time,and *** revealed that all virgin dispersions lacked *** X-100,a non-ionic surfactant,was added to ZB/SO dispersions to enhance the polarizability of ZB *** addition of 1vol% Triton X-100 enhanced the polarizability of ZB/SO dispersions,and the 15vol% ZB/SO system provided the highest dielectric difference Δε′(the difference in ε′values at zero and infinite frequency,Δε′=ε0–ε∝)of *** electrorheological(ER)activities of the ZB/SO/Triton-X dispersion system were determined through the ER response test,and viscoelastic behaviors were investigated via oscillation tests.A recoverable deformation of 36% under an applied electrical field strength of 1.5 kV/mm was detected through creep and creep recovery tests.

关键词： zinc borate electrorheological fluids dielectric analysis surfactant

Dielectric and microstructural properties of YAG:Dy^(3+) ceramics

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Journal of Rare Earths 2018年第12期36卷 1310-1318页

作者： Munirah Abdullah Almessiere Bayram unal Abdulhadi Baykal Department of Physics College of Science Imam Abdulrahman Bin Faisal University Department of Nanomedicine Research Institute for Research & Medical Consultations (IRMC) Imam Abdulrahman Bin Faisal University Department of Software and Computer Engineering Istanbul Sabahattin Zaim University

Yttrium aluminium garnet(Y3Al5O12:YAG) singly doped with Dy3+ at different concentrations was prepared by solid state reactions using repeated heating cycles over the temperature range of 1300-1600 ℃. X-ray powder diffraction analysis confirms the presence of a well-crystallized YAG perovskite phase with cubic structure(by Rietveld refinement). The rare earth dopant is successfully integrated into the YAG host lattice without any major changes in the original structure. The temperature dependence,up to 250 ℃, of the conductivity, dielectric constant, dielectric loss, and loss tangent, at various frequencies of up to 5.0 MHz for undoped and doped crystals is compared to understand the electrical and structural characteristics. The experimental results reveal that Dy3+ dopants in YAG crystal significantly influence the conductivity, dielectric constant, and lossy mechanisms, which is probably due to the 3 d-AI ions and 4 f-Dy ions incorporated at different positions of both tetrahedral and octahedral symmetries in YAG:xDy3+ ceramics.

关键词： Yttrium aluminium garnet(YAG) X-ray diffraction(XRD) Conductivity Dielectric properties Rare earths

Steady State Heat Transfer of Ladle Furnace During Steel Production Process

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Journal of Iron and Steel Research International 2006年第3期13卷 18-20,25页

作者： unal Camdali Murat.Tun Development Bank of Turkey Ankara 06100Turkey Engineering Faculty Yeditepe UniversityIstanbul 81120 KayιsdagιTurkey

The heat transfer analysis was performed for an industrial ladle furnace （LF） with a capacity of 55-57 t in Turkey. The heat losses by conduction, convection and radiation from outer and bottom surfaces, top and ele... 详细信息

关键词： heat transfer ladle furnace refining liquid steel