gazi university journal of science最新文献_第8页

Discretization and Stability Analysis for a Generalized Type Nonlinear Pharmacokinetic Models 一类广义非线性药代动力学模型的离散化及稳定性分析

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gazi university journal of science Pub Date : 2022-12-19 DOI: 10.35378/gujs.1027381

M. Kocabiyik, Mevlüde YAKIT ONGUN

引用次数: 0

Analytical modeling of buckling of carbon nanotubes reinforced sandwich-structured composite shells resting on elastic foundations 碳纳米管增强三明治结构复合材料壳弹性地基屈曲分析模型

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gazi university journal of science Pub Date : 2022-12-14 DOI: 10.35378/gujs.998265

A. Timesli

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Recommendations for Improvement of the Thermal Performance of an Office Building Based on Retrofitting the Glazed Curtain Wall 基于玻璃幕墙改造的办公楼热工性能改善建议

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gazi university journal of science Pub Date : 2022-12-08 DOI: 10.35378/gujs.997496

Neşe Di̇kmen, Canan Altundaş

{"title":"Recommendations for Improvement of the Thermal Performance of an Office Building Based on Retrofitting the Glazed Curtain Wall","authors":"Neşe Di̇kmen, Canan Altundaş","doi":"10.35378/gujs.997496","DOIUrl":"https://doi.org/10.35378/gujs.997496","url":null,"abstract":"Glazed curtain wall systems have become indispensable particularly in office buildings due to their light weight, aesthetic appearance, easy installation and resistance to climate conditions. Curtain walls however, also have problems in terms of thermal efficiency because of their wide, glazing windows and metal frames that have high thermal conductivity. The aim of this study is to offer proposals for improving the thermal performance of an office building with a glass curtain wall system built in a hot-humid climate zone. An office building constructed in Antalya, Turkey was modelled with the help of DesignBuilder energy simulation software and various modifications were made on the model in order to improve the thermal performance of the building. With the improvements proposed in the study, it is possible to decrease the annual thermal loads of the whole building by 6.6%, and the annual thermal loads of the space with the curtain wall by 33.2%. The study revealed that, applying an additional envelope is more effective than lowering the U-value of the glass of the curtain wall in terms of thermal performance improvement.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46020440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sintering of Iron Powders by Resistance Heating Technique 用电阻加热技术烧结铁粉

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gazi university journal of science Pub Date : 2022-12-05 DOI: 10.35378/gujs.1003395

F. Atar, A. Kurt

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Review of the Definition of Weld Penetration, Depth of Fusion and Throat Thickness on Fillet Welds 角焊缝熔深、熔深和喉道厚度定义的回顾

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gazi university journal of science Pub Date : 2022-12-01 DOI: 10.35378/gujs.1137178

Umut Yaşar Uzunali, H. Çuvalcı

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Investigation of Hydrogen Diffusion Profile of Different Metallic Materials for a Better Understanding of Hydrogen Embrittlement 研究不同金属材料的氢扩散曲线，更好地理解氢脆

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gazi university journal of science Pub Date : 2022-11-21 DOI: 10.35378/gujs.1090824

M. F. Kapci, B. Bal

{"title":"Investigation of Hydrogen Diffusion Profile of Different Metallic Materials for a Better Understanding of Hydrogen Embrittlement","authors":"M. F. Kapci, B. Bal","doi":"10.35378/gujs.1090824","DOIUrl":"https://doi.org/10.35378/gujs.1090824","url":null,"abstract":"In this study, hydrogen diffusion profiles of different metallic materials were investigated. To model hydrogen diffusion, 1D and 2D mass diffusion models were prepared in MATLAB. Iron, nickel and titanium were selected as a material of choice to represent body-centered cubic, face-centered cubic, and hexagonal closed paced crystal structures, respectively. In addition, hydrogen back diffusion profiles were also modeled after certain baking times. Current results reveal that hydrogen diffusion depth depends on the microstructure, energy barrier model, temperature, and charging time. In addition, baking can help for back diffusion of hydrogen and can be utilized as hydrogen embrittlement prevention method. Since hydrogen diffusion is very crucial step to understand and evaluate hydrogen embrittlement, current set of results constitutes an important guideline for hydrogen diffusion calculations and ideal baking time for hydrogen back diffusion for different materials. Furthermore, these results can be used to evaluate hydrogen content inside the material over expensive and hard to find experimental facilities such as, thermal desorption spectroscopy.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69795962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

CO Methanation Over SAPO-34 Supported Ni Catalysts SAPO-34负载镍催化剂上的CO甲烷化

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gazi university journal of science Pub Date : 2022-10-21 DOI: 10.35378/gujs.1125710

Filiz BALIKÇI DEREKAYA, Y. Kilinç

{"title":"CO Methanation Over SAPO-34 Supported Ni Catalysts","authors":"Filiz BALIKÇI DEREKAYA, Y. Kilinç","doi":"10.35378/gujs.1125710","DOIUrl":"https://doi.org/10.35378/gujs.1125710","url":null,"abstract":"In this study, carbon monoxide methanation was investigated with 15 %NiO doped SAPO34 zeolite supported catalysts. The SAPO34 support was produced by hydrothermal synthesis, and nickeloxide was added to the support by impregnation and surfactant impregnation method by using different solvents (water, ethanol, acetone and 1-propanol). Various characterization techniques were used to determine the physical properties of catalysts and support (N2 physisorption, XRD, SEM, TEM, FTIR). XRD analysis showed that synthesizing the catalysts with surfactant reduced the average crystal size. The average crystal sizes of the catalysts prepared by the impregnation and surfactant assisted impregnation methods are between 11.3-7.1 nm and 8.9-7.1 nm, respectievely. N2 physisorption analysis showed that catalysts prepared by the surfactant-assisted impregnation method had higher surface areas than the catalysts prepared by the classical impregnation method. It was observed that the surface area of the catalyst increased as the boiling point of the solvent increased. Scanning electron microscopy (SEM) analysis showed that particle size of the catalysts with propanol prepared by impregnation and surfactant assisted impregnation methods are 118 nm and 86 nm, respectievely. Surfactant caused to produce smaller particles. The CO methanation studies showed that highest CO conversion values were reached with Ni/SAPO34 catalyst using 1-propanol prepared by impregnation and surfactant assisted impregnation methods which gave 19.2% and 21.1% CO conversion to methane at 375C, respectievely The low methane formation rates showed that most of the CO component was adsorbed on the surface and some of it was converted to methane.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42808765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Parametric Examination Anisotropic Thermal Resistance of MIL Composites MIL复合材料各向异性热阻参数检测

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gazi university journal of science Pub Date : 2022-10-20 DOI: 10.35378/gujs.1122095

Kübra Solak, R. Mutlu

引用次数: 0

COMPARİSON OF EGG WHİTE AND Ε-POLYCAPROLACTONE FOR THREE-DİMENSİONAL CELL CULTURE 鸡蛋WHïTE和聚己内酯用于三天细胞培养的比较

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gazi university journal of science Pub Date : 2022-10-20 DOI: 10.35378/gujs.1037746

Olga Nehir Öztel, H. Yilmaz, I. A. Işoğlu, A. Allahverdiyev

{"title":"COMPARİSON OF EGG WHİTE AND Ε-POLYCAPROLACTONE FOR THREE-DİMENSİONAL CELL CULTURE","authors":"Olga Nehir Öztel, H. Yilmaz, I. A. Işoğlu, A. Allahverdiyev","doi":"10.35378/gujs.1037746","DOIUrl":"https://doi.org/10.35378/gujs.1037746","url":null,"abstract":"It is increasingly becoming important to develop three-dimensional (3-D) cell culture systems due to their numerous advantages over traditional monolayer culture. The aim of this study is to investigate the interaction of adipose derived stem cells (ADSCs) with scaffolds composed of ε-polycaprolactone (ε-PCL) and egg white. In our study; ε-PCL and egg white scaffolds were fabricated from their monomers under the catalysis of tin octoate and by polymerization by heat respectively. Characterization of PCL was carried out with Gel permeability chromatography (GPC), Fourier Transform Infrared Spectrophotometry (FTIR), Proton Nuclear Magnetic Resonance (H-NMR), Differential Scan Calorimetry (DSC) and Scanning Electron Microscopy (SEM). CM-DiI labeled ADSCs were cultured for 12 days on egg white and ε-PCL scaffolds. Cell viability was performed using MTT and nitric oxide level was evaluated for toxicity. Results showed that the number of ADSCs on egg white scaffold increased periodically throughout 12 days compared with the other groups. Although the number of ADSCs on ε-PCL scaffold increased until the 6th day of the culture, the cell number began to decrease after day 6.. These results were associated with the decomposition of PCL scaffolds that occurs through catabolic reactions. This causes the release of lactic acid which makes toxic effect on the cells. Thus, these results showed that egg white scaffold increases and protects cell adhesion and cell viability more than ε-Polycaprolactone scaffold, thus it can be used as a scaffold in tissue engineering studies that involve stem cells.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41286769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Providing homeland security strategies against interdictions in the city transportation network: A case study in Turkey 针对城市交通网络中的拦截提供国土安全策略：以土耳其为例

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gazi university journal of science Pub Date : 2022-10-19 DOI: 10.35378/gujs.1103774

E. Ayyıldız, Gökhan Özçelik, Cevriye Gencer, E. Demirci

{"title":"Providing homeland security strategies against interdictions in the city transportation network: A case study in Turkey","authors":"E. Ayyıldız, Gökhan Özçelik, Cevriye Gencer, E. Demirci","doi":"10.35378/gujs.1103774","DOIUrl":"https://doi.org/10.35378/gujs.1103774","url":null,"abstract":"This paper defines a capacitated multiple-source multiple-sink shortest path problem and introduces its extension, called the capacitated multiple-source multiple-sink shortest path network interdiction problem (CMSSNIP). CMSSNIP examines the actions of attackers who attempt to maximize the total shortest path of network users trying to reach the crime locations for the aid process after causing an incident in certain regions to provide strategic information for the defense systems of the government. In this context, the exact mathematical model ensuring useful information about safe routes to network users is proposed. In this manner, to the best knowledge of authors, the CMSSNIP consisting of multiple-source nodes and multiple-sink nodes and considering capacity-demand relations between security units and crime locations is studied for the first time. Accordingly, a set of scenarios is considered based on the interdiction budget levels and the number of crime locations through a real case application to show the applicability of the model. Furthermore, computational experiments are performed to evaluate the model performance on different-sized networks. It is realized that especially the model provides resilient strategies versus interdictions in terms of obtaining the safe shortest paths at the operational level within seconds in the real case application.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45618343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0