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A comparative assessment of rock mass deformation modulus

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International Journal of Mining Science and Technology 2015年第5期25卷 735-740页

作者： Kadir Karaman Ferdi Cihangir ayhan Kesimal Department of Mining Engineering Karadeniz Technical University

Deformation modulus of a rock mass(E_m) is one of the most important design parameters in construction of rock engineering projects such as underground ***,difficulties are frequently encountered during in-situ tests which are also time-consuming and expensive for determining this *** E_m is often estimated indirectly from proposed equations by different researchers,many of these equations cannot be used in case of problematic rock conditions(thinly bedded,highly jointed rock masses,etc.) as high quality core samples are *** study aims to explore more practical and useful equation for E_m estimation using Rock Quality Designation(RQD) and point load index *** were made between available empirical equations and the proposed E_m equation in terms of the estimation *** comparison tests(ANOVA) showed that E_m can be reliably estimated using proposed equation especially at the preliminary stages of projects.

关键词： Rock mass deformation modulus RQD RMR Q RMi Point load index

Evaluation of Two-center One- and Two-electron Integrals over Slater Type Orbitals

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Chinese Journal of Chemistry 2006年第5期24卷 603-608页

作者： YAKAR, Yusuf OZMEN, ayhan ATAV, Ulfet Department of Physics Faculty of Arts and Science at Aksaray Nigde University Aksaray Turkey Department of Physics Faculty of Arts and Science Selcuk University Konya Turkey

A formulation previously presented by the authors for coulomb integrals was generalized to other two-center integrals, except exchange integral. Within this frame, molecular integrals were expressed in terms of some new functions closely related to the well-known incomplete gamma functions and these functions recursively evaluated. Special issues arising in the case of hybrid integrals were addressed, and the results were compared with the ones found in the literature.

关键词： overlap integral hybrid integral coulomb integral Slater type orbital elliptical coordinate

Impact of central venous port implantation method and access choice on outcomes

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World Journal of Clinical Cases 2023年第1期11卷 116-126页

作者： ayhan Erdemir Huseyin Kemal Rasa Department of General Surgery Anadolu Medical CenterKocaeli 41400Turkey Department of General Surgery Anadolu Medical Center HospitalKocaeli 41400Turkey

BACKGROUND Although the number of patients who need central venous ports for permanent vascular access is increasing,there is still no“gold standard”for the implantation *** To identify the implantation technique that should be *** Two hundred central venous port-implanted patients in a tertiary hospital were retrospectively *** were assigned into two groups according to the access *** first group comprised patients whose jugular veins were used,and the second group comprised patients whose subclavian veins were *** were evaluated regarding age,sex,application side,primary diagnosis,active follow-up period in the hospital,chemotherapy agents administered,number of complications,and the Clavien-Dindo severity *** distribution of the variables was tested with the Kolmogorov-Smirnov test and the Mann-Whitney U ***χ^(2) test was used to analyze the *** There was no statistically significant difference between the groups regarding age,sex,side,number of chemotherapy drugs,and duration of port usage(P>0.05).Only 2 patients in group 1 had complications,whereas in group 2 we observed 19 patients with complications(P<0.05).No port occlusion was found in group 1,but the catheters of 4 patients were occluded in group *** port was infected in group 1 compared to three infected ports in group *** port ruptures,two pneumothorax,one revision due to a mechanical problem,one tachyarrhythmia during implantation,and four suture line problems were also recorded in group 2 *** also showed that it would be sufficient to evaluate and wash ports once every 2 *** Our results robustly confirm that the jugular vein route is safer than the subclavian vein approach for central venous port implantation.

关键词： Permanent vascular access Central venous ports Central venous port implantation methods Jugular vein route Subclavian vein approach Impact of implantation method on outcomes

Linear and Nonlinear Optical Properties in Spherical Quantum Dots

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Communications in Theoretical Physics 2010年第6期53卷 1185-1189页

作者： Yusuf Yakar Bekir Cakir ayhan Ozmen Physics Department Faculty of Science and Letters Aksaray University Physics Department Faculty of Science Selcuk University

We calculate the energy eigenvalues and the sate functions of one-electron Quantum Dot （QD） by using a combination of Quantum Genetic Algorithm （QGA） and Hartre-Fock-Roothaan （HFR） method. The linear and the third-order nonlinear optical absorption coefficients for the 1s-1p, 1p-1d, and 1d-1f transitions are examined as a function of the incident photon energy for three different values of the stoichiometric ratio. The results show that the stoichiometric ratio, impurity, relaxation time, and dot size have great influence on the optical absorption coefficients of QDs.

关键词： optical properties spherical quantum dot QGA and HFR method

Determining the safety of kefir grains for public health

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FOOD BIOSCIENCE 2023年第3期53卷 1649-1656页

作者： Cirpici, burcu Bazu Cetin, Bulent Ataturk Univ Fac Agr Dept Food Engn TR-25240 Erzurum Turkiye

In this study, kefir grains and kefir produced from contaminated grains were investigated in terms of food safety. For this aim, traditional kefir grains were collected from distinct parts of Turkey, and their pathogenicity was examined. Typical and non-typical colonies were isolated on Violet Red Bile Agar and identified for the first time at species level. Antibiotic resistance and hemolytic activity of the isolates were also determined. Coliform and pathogenic bacteria was found in 19 out of 30 kefir grains tested (63.33%). Although Hafnia paralvei was the predominant group, Klebsiella oxytoca, Citrobacter freundii, Serratia liquefaciens, and Escherichia coli were also identified among the 27 strains as the pathogenic bacteria. It was found that the bacterial count of kefir produced from two kefir grains containing pathogenic bacteria was 8.44 log CFU/mL and 8.20 log CFU/mL at the end of the 10th day. All isolates were sensitive to ciprofloxacin, nalidixic acid, meropenem, and ertapenem but resistant to ampicillin and vancomycin. Furthermore, all strains were found to be beta-hemolytic in that study. As a result, it was determined that traditionally produced kefir can be risky in terms of food safety due to contaminated kefir grains and this risk continues throughout consumption.

关键词： Kefir grains Coliform bacteria Pathogenic bacteria Antibiotic resistance Hemolytic activity

Wear Behavior of Plasma Oxidized CoCrMo Alloy under Dry and Simulated Body Fluid Conditions

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Journal of Bionic Engineering 2014年第2期11卷 303-310页

作者： ayhan Celik Mevra Asian Ali Fatih Yetim Ozgii Bayrak Department of Mechanical Engineering Engineering Faculty Atatiirk University Erzurum 25240 Turkey Department of Mechanical Engineering Engineering and Architecture Faculty Erzurum Technical University Erzurum 25700 Turkey

In this study, CoCrMo alloy was oxidized in plasma environment at the temperatures of 600 ℃ to 800 ℃ for 1 h to 5 h with 100% 02 gas and its tribological behavior was investigated. After the plasma oxidizing process, the compound and diffusion layers were formed on the surface. XRD results show that Cr203, a-Co and ε-Co phases diffracted from the modified layers after plasma oxidizing. The untreated and treated CoCrMo samples were subjected to wear tests both in dry and simulated body fluid conditions, and normal loads of 2 N and 10 N were used. For the sliding wear test, alumina balls were used as counter materials. It was observed that the wear resistance of CoCrMo alloy was increased after the plasma oxidizing process. The lowest wear rate was obtained from the samples that were oxidized at 800 ℃ for 5 h. It was detected that both wear environment and load have significant effects on the wear behavior of this alloy, and the wear resistance of oxidized CoCrMo alloy is higher when oxide-based counterface is used. The wear rates of both untreated and plasma oxidized samples increase under high loads.

关键词： plasma oxidation wear CoCrMo simulated body fluid implant material

Cell-to-cell proteome variability:life in a cycle

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Signal Transduction and Targeted Therapy 2021年第7期6卷 1939-1941页

作者： Tsz Kin Suen burcu Al Katarzyna Placek Immunology and Metabolism Life and Medical Sciences InstituteUniversity of BonnBonnGermany

Increasing body of evidence,supported by single-cell transcrip-tomic analysis,points to the heterogeneity of single cells within same cell *** the recent study by Mahdessian et al.1 published in Nature the authors elegantly show the cell-to-cell variability in the protein expression,its(in)dependence on the cell cycle progression and provide with the list of new cycling proteins with a potential role in tumorigenesis.

关键词： population cycle

Experimental study of polyurethane foam reinforced soil used as a rock-like material

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Journal of Rock Mechanics and Geotechnical Engineering 2015年第5期7卷 566-572页

作者： Eren Komurlu ayhan Kesimal Department of Mining Engineering Karadeniz Technical University

In this study, p o ly u reth an e foam ty p e th e rm o se t polym erizing, d u e to chem ical reaction b e tw e e n itsliquid ingredients, w as teste d as b in d e r afte r solidifying and th e n a rock-like m aterial m ixing w ith asandy silt ty p e soil w as prep ared . The uniaxial com pressive stren g th s （UCSs） o f p o ly u reth an e foamreinforced soil specim ens w ere d e term in ed for different p o ly u reth an e ratios in th e m ixture. A dditionally,a series o f te sts o n slake durability, im pact value, freezing-th aw in g resistance, and ab rasio n resistance ofp o ly u reth an e reinforced soil （PRS） m ix tu re w as co n d u cted . The UCS values over 3 M Pa w ere m easuredfrom th e PRS specim ens. The testin g results show ed th a t tre a te d soil can econom ically b ecom e adesirable rock-like m aterial in term s o f slake d u ra b ility a n d resistances ag ain st freezing-thaw ing, im pacteffect an d abrasion. As a n o th e r ch aracteristic o f th e rock-like m aterial m ade w ith p o ly u reth an e foam,u n it volum e w eig h t w as found to be q uite low er th a n th o se o f n atu ral rock m aterials.

关键词： Polyurethane reinforced soil(PRS) Rock-like material Polyurethane Environmental resistance of rocks Rock testing

Evaluation of the Polar Code in different environments and for different maritime activities in the two polar regions

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Advances in Polar Science 2020年第4期31卷 237-240页

作者： Meric KARAHALIL burcu OZSOY Istanbul Technical University Maritime FacultyTuzlaIstanbulTurkey Scientific and Technological Research Council of Turkey(TUBITAK MAM) Polar Research Institute(KARE)GebzeIstanbulTurkey

Because of the decrease in sea ice coverage,maritime activities in the polar regions have increased steadily over the years and several issues related to maritime activities have *** is essential to understand these challenges because they could have serious political,environmental,and economic *** there are significant geographical and legal differences and differences in the types of activities between the Arctic and the Antarctic,a single International Maritime Organization Polar Code covers both *** this analysis,changes in polar regions are introduced,and the differences between the Arctic and Antarctic are *** differences in maritime activities in the two polar regions are then discussed,and the Polar Code is evaluated in terms of these differences.

关键词： polar regions sea ice maritime activities Polar Code