Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/395
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Article Citation - WoS: 15Citation - Scopus: 15The Effects of Pyrite Ash on the Compressive Strength Properties of Briquettes(Korean Society of Civil Engineers-ksce, 2012-11) Sola, Ozlem Celik; Atis, Cengiz DuranThe aim of this study is to investigate the utilization of Pyrite Ash (PA) in the production of briquettes as a replacement of clay or soil. To achieve this, first, the characterization of the materials used (clayey soil and pyrite ash) was made using Fourier Transform Infrared Spectroscopy (FTIR/ATR). Particle size distribution and microstructure elemental analyses of these materials were also obtained using a particle size analyzer (Mastersizer) and a Scanning Electron Microscope (SEM). Following the characterization of the materials, the samples of briquettes made with or without addition of PA were prepared and sintered at 950 and 1000A degrees C in the furnace. The PA replacement ratios with clayey soil were 0, 5, 10, 20% in mass basis (w/w). Compressive strength and bulk densities of briquettes produced were measured and the results were presented. Compressive strength results of the briquette samples indicated that pyrite ash containing briquettes with 35 MPa compressive strength, which was higher than the requirements of Turkish Standard Specification (TS EN 771-1), can be obtained. It is also recorded that for each mixture, compressive strength values obtained at 1000A degrees C were higher than that of obtained at 950A degrees C. XRD analyze was performed on sintered briquette sample made with 10% PA which have the highest compressive strength value. The XRD results showed that peaks are Quartz (SiO2), Hematite (Fe2O3), Ortoclase (KAlSi3O8), Albite (Na(AlSi3O8)), Anorthite (CaAl2Si2O8) and Gehlenite (2CaO.Al2O3.SiO2).Article Citation - WoS: 14Citation - Scopus: 16Production of Cross-Linked Resistant Starch From Tapioca Starch and Effect of Reaction Conditions on the Functional Properties, Morphology, X-Ray Pattern, Ft-Ir Spectra and Digestibility(Springer, 2021-01-02) Korkut, Ayse; Kahraman, KevserThe aim of this study was to investigate the effect of cross-linking temperature and pH on resistant starch (RS) formation as well as the functional, structural and morphology properties of tapioca starch. Tapioca starch was cross-linked using sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP) at various temperature and pH. Increase in the reaction temperature and pH increased RS content and decreased swelling power (SP) of the samples. The sample cross-linked at 60 degrees C and pH 12 had the highest RS content (84.8%) and the lowest SP (3.0 g/g). The correlation coefficient between RS content and SP was 0.96. Cross-linking altered the pasting behavior significantly, while Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) patterns changed slightly. Cross-linking did not change the morphological structure and granular shape of the starch. In addition, cross-linked samples protect their original shapes during cooking and in vitro digestion probably since cross-linking restrict the water uptake and swelling due to the increase in the bonds within the molecule. Overall results proved that cross-linking at high temperature and high alkaline condition resulted in an increase in the RS content of tapioca starch.Conference Object Evaluation of the Performance of Geotextiles Using Finite Element Analysis in the Settlement Results: A Case Study in Kayseri, Turkey(Korean Geosynthetics Society, 2018) Yalçın, Hakan; Akin, Muge K.; Çabalar, Ali FiratGeotextiles are successfully designated for the reinforcement of soils to solve certain settlement as well as bearing capacity problems in difficult ground conditions. Furthermore, geotextiles are used for the stability of man-made slopes. In this study, the performance of geotextiles for soil improvement is evaluated by considering various geotextile types that have different axial stiffness values. The stiffness values are compared using a finite element method (FEM) based software PLAXIS 2D. As case study, Kayseri Organized Industrial Site in Turkey was chosen for the comparison of these geotextiles for a specific soil profile during analyses. Besides, the FEM based approach is also considered for the settlement, axial force and the effective stress changes during the application of geotextiles. The selected geotextiles are also correlated using scanning electron microscope (SEM) analyses. The results indicated that the axial stiffness (EA) can be considered with the effect on the possible soil settlement and axial force values. The settlement values reduced with increase in stiffness of reinforcement. © 2021 Elsevier B.V., All rights reserved.