Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - Scopus: 3Characteristics of Byzantine-Period Lime Mortars and Plasters From the Anaia Church (kadikalesi)(Institute of Metals Technology, Ljubljana, 2022) Işık, Tuğçe; Uğurlu Sağın, ElifIn this study, Byzantine- period lime mortars and plasters used in the Anaia Church in Ku degrees adasy- Aydyn were examined in order to determine their characteristics and investigate the continuity of the lime mortar technology through centuries in the Anaia Church. The results will also contribute to future conservation studies at the site. Basic physical properties, raw-material compositions and hydraulic properties of lime mortars and plasters; mineralogical and chemical compositions, microstructural properties of binders, aggregates and limes; and pozzolanic activities of aggregates were determined using RILEM test methods, XRD, SEM-EDS and TGA. Mortar samples were comprised of natural aggregates whereas lime plasters were made of brick aggregates. Analyses revealed that plasters were slightly less dense and more porous than mortars due to the porous structure of the brick aggregates. All mortars and plasters were hydraulic due to the use of highly reactive pozzolanic aggregates. The basic physical properties, raw-material compositions, mineralogical and chemical compositions of mortars and plasters were found to be similar throughout the construction periods spread over different centuries. These similarities revealed the conscious knowledge of the lime mortar technology during the Byzantine period in Western Anatolia.Article Citation - Scopus: 1Enhancement of Cerium Exchange With Ultrasound(Turkish Chemical Society, 2018) Çakıcıoğlu Özkan, Fehime; Erten Kaya, YaseminIn this study the effect of ultrasound of the cerium exchange was studied. The results were compared to those obtained from traditional batch exchange method. Contact time, initial cation concentration (fold equivalent excess) and the types of the ultrasound were studied. Ultrasonic probe, which is the most effective method, enhanced the replacement of Na+ ion with Ce3+ ion in the extra-framework of zeolite up to 73 % by applying 5 consecutive ion exchanges. The cerium in the solution caused to be formed cerium oxides on the crystal surface occluding the pores. Thus the specific surface area of cerium exchanged zeolite was decreased due to formation of cerium complexes on the surface and into the pores. © 2018, Turkish Chemical Society. All rights reserved.Article Citation - WoS: 17Citation - Scopus: 20Preparation and Characterization of Antibacterial Cobalt-Exchanged Natural Zeolite/Poly(vinyl Alcohol) Hydrogels(Springer Verlag, 2014) Narin, Güler; Bulut Albayrak, Çisem; Ülkü, SemraIn the present study, potential application of the local clinoptilolite-rich natural zeolite in formulation of antibacterial hydrogels was investigated. The zeolite powder exchanged with cobalt(II) ions was used in preparation of the zeolite/poly(vinyl alcohol) hydrogel films in different amounts. The films were physically crosslinked by the freezing-thawing method and characterized for their crystallinity, surface and cross sectional morphology, chemical composition, thermal behaviour, mechanical properties, swelling and dissolution behaviours, and antibacterial activities against a Gram-negative bacteria. The films with 0.48 wt% and higher cobalt-exchanged zeolite contents showed antibacterial activity. Addition of the zeolite powder in the formulations did not cause significant changes in the other properties of the films.Article Citation - WoS: 3Citation - Scopus: 4Electrical Characterization of Interdigitated Humidity Sensors Based on Cnt Modified Calixarene Molecules(Polish Academy of Sciences, 2013) Özbek, Cebrail; Çulcular, Evren; Okur, Salih; Yılmaz, M.; Kurt, M.In this study, we report on the optimization and characterization of chloroform soluble calix[4]arene derivative as a humidity sensor based on electrical properties. Due to the fact that calix[4]arene molecules are nonconductive, we modified the calix[4]arene molecules with carbon nanotubes with electrostatic bond in order to increase the conductance of calix[4]arene molecule (5,11,17,23-tetra-ter-butyl-25,27-dehydrazinamidcarbonilmetoxy-26,28- -dehydroxy-kalix[4]aren). Using photolithography technique, we fabricated interdigitated gold electrodes with 3 micrometers separation to investigate the electrical properties of carbon nanotubes modified calix[4]arene molecule where we used dropcast method to form a thin film of carbon nanotubes modified calix[4]arene molecule on the gold electrodes. Our reproducible experimental results indicated that the chloroform soluble carbon nanotubes modified calix[4]arene films have great potential for humidity sensing applications at room temperature operations.Article Citation - WoS: 3Citation - Scopus: 4Electrical Characterizations of Schottky Diodes on Ito Modified by Aromatic Sams(Polish Academy of Sciences, 2013) Havare, A. Kemal; Okur, Salih; Yağmurcukardeş, Nesli; Can, M.; Aydın, H.; Şeker, M.; Demiç, ŞerafettinIn order to understand the electronic properties of the organic Schottky diode, ITO/TPD/Al and ITO/SAM/ TPD/Al organic Schottky devices were fabricated to obtain currentffvoltage characteristics. From the slopes and y-axis intercepts of the plots, the values of the ideality factor, barrier heights of the ITO/SAM/TPD/Al diode were determined as 2.03 and 0.56 eV, respectively. The surface characterizations of modified and unmodified ITO were performed via atomic force microscopy.Article Citation - WoS: 1Citation - Scopus: 1Improvement of Anode/Htl Interface Properties Using Self-Assembled Monolayer in Organic Electronic Devices(Polish Academy of Sciences, 2013) Yaman, M.; Yağmurcukardeş, Nesli; Havare, A. Kemal; Aydın, H.; Ocakoğlu, Kasım; Okur, SalihFabrication and characterization of highly effcient organic light-emitting diode with surface modification of indium tin oxide anodes by using self-assembled monolayer technique have been studied. Four different self-assembled molecules, K-28 ruthenium complex, octadecylamine hydrochloride, octadecyltrichlorosilane and mercaptohexdecanoic acid are used to modify ITO surface to improve the interface properties. Space charge limited currents measurements have been used to evaluate carrier mobility under steady state current. The results show that the surface properties such as the stability of ITO anode layer have significant effects on charge injection in organic light-emitting diode devices.Article Citation - WoS: 23Citation - Scopus: 28Classification of Turkish Monocultivar (ayvalık and Memecik Cv.) Virgin Olive Oils From North and South Zones of Aegean Region Based on Their Triacyglycerol Profiles(John Wiley and Sons Inc., 2013) Gökçebag, Mümtaz; Dıraman, Harun; Özdemir, DurmuşIn this study, a total of 22 domestic monocultivar (AyvalIk and Memecik cv.) virgin olive oil samples taken from various locations of the Aegean region, the main olive growing zone of Turkey, during two (2001-2002) crop years were classified and characterized by well-known chemometric methods (principal component analysis [PCA] and hierarchical cluster analysis [HCA]) on the basis of their triacylglycerol (TAG) components. The analyses of TAG components (LLL and major fractions LOO, OOO, POO, PLO, SOO, and ECN 42-ECN 50) in the oil samples were carried out according to the HPLC method described in a European Union Commission (EUC) regulation. In all analyzed samples the value of trilinolein (LLL), the least abundant TAG, did not exceed the maximum limit of 0.5 % given by the EUC regulation for different olive oil grades. The ranges of abundant TAG, namely LOO, OOO, POO, PLO, and SOO, were 13.30-16.08, 37.27-46.36, 21.39-23.24, 4.93-7.03, and 4.72-6.00 %. The TAG data of Aegean virgin olive oils were similar to those of products from important olive-oil-producing Mediterranean countries was determined. Also, the estimation of major fatty acids (FA) was carried out by using a formula based on TAG data. The PCA results showed that some TAG components have an important role in the characterization and geographical classification of 22 monocultivar virgin olive oil. The Aegean virgin olive oil samples were successfully classified and discriminated into two main groups as the North and South (growing) subzones or AyvalIk and Memecik olives (cultivars) according to the HCA results based on experimental TAG data and calculated major FA profile.Article Citation - WoS: 13Citation - Scopus: 14Characterization and Dehydration Behavior of a Natural, Ammonium Hydroxide, and Thermally Treated Zeolitic Tuff(Taylor and Francis Ltd., 2011) Narin, Güler; Balköse, Devrim; Ülkü, SemraAqueous NH4OH-treated and subsequently calcined forms of local natural zeolitic tuff were characterized by different techniques including scanning electron microscopy (SEM), X-ray powder diffraction, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), volumetric N2 adsorption at -196°C, thermogravimetry (TG), differential scanning calorimetry (DSC), and transmittance infrared spectroscopy. The dehydration behavior of the samples was investigated using an in situ temperature-programmed diffuse reflectance Fourier transform infrared spectroscopy (TP-DRIFTS) method under vacuum. The DRIFTS spectra recorded yielded information about the effect of the NH4OH treatment and subsequent calcination on the dehydration behavior of the natural zeolite.Changes in the infrared bands corresponding to vibrations of the O-H and N-H bonds upon in situ heating under vacuum were analyzed.Article Citation - WoS: 23Citation - Scopus: 26Cr(vi) Sorption by Using Clinoptilolite and Bacteria Loaded Clinoptilolite Rich Mineral(Elsevier Ltd., 2012) Cansever Erdoğan, Beyhan; Ülkü, SemraBatch sorption experiments were performed in order to understand the potential value of local clinoptilolite rich mineral and its bacteria loaded form in Cr(VI) sorption. The results indicated that Cr(VI) sorption capacities of the sorbents were increased after bacteria loading and the clinoptilolite rich mineral is a promising material in Cr(VI) sorption. Zeta potential and Fourier Transform IR (FTIR) analysis were performed to explain the possible mechanism involved in the Cr(VI) sorption. The results revealed that non-electrostatic forces played a significant role rather than the electrostatic forces. The existence of non-electrostatic forces was confirmed by the FTIR results. © 2011 Elsevier Inc. All rights reserved.Article Citation - WoS: 18Citation - Scopus: 21Evaluation of Heat Treated Clay for Potential Use in Intervention Mortars(Elsevier Ltd., 2010) Budak, Meral; Akkurt, Sedat; Böke, HasanIn this study, raw material compositions, basic physical, mineralogical, microstructural and hydraulic properties of lime mortars used in two selected historic buildings were determined by XRD, SEM-EDS and TGA analyses. The results showed that the mortars were hydraulic due to the use of pozzolanic aggregates. Taking into account the hydraulic characteristics of mortars due to the use of pozzolanic aggregates, the possibility of obtaining hydraulic mortars by using pozzolanic aggregates produced from heated commercial clays was investigated. For this purpose, four clay samples used in the ceramic industry in Turkey were heated at varying temperatures of 400, 450, 500, 550, 600, 800, and 1200°C with a heating rate of 10°C/min. Pozzolanic properties of heated clay samples were determined. The results showed that commercial clays studied are well suited for use as pozzolanic aggregates when they are heated between 500 and 700. °C. This is also confirmed by testing the compressive strengths of the three month aged laboratory-produced mortars that contained thermally treated clay (at 600°C) as pozzolanic aggregates. Compressive strength of this mortar was around 5. MPa which is satisfactorily high. © 2009 Elsevier B.V.