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Publication Metadata only Investigation of adsorption of 5-Chlorouracil onto montmorillonite: An IR and Raman spectroscopic study(Elsevier, 2018-11) AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANIL; 10127In this study, the adsorption of 5-Chlorouracil (5-ClU) on natural montmorillonite from Anatolia was investigated using FT-IR and Raman spectroscopy. The 5-ClU is a thymine antagonist and has some antitumor properties. The comparison of the vibrational spectra of the adsorbed 5-ClU with those of the free molecule provided data on the nature and characteristics of the clay organic complexes. The intercalation of 5-ClU within montmorillonite has been shown by X-ray diffraction to increase the interlayer spacing. Vibrational spectroscopy indicates that adsorbed 5-ClU molecules on montmorillonite are coordinated to exchangeable cations, directly or indirectly through water bridges.Publication Metadata only Temperature Dependent FT IR Spectroscopic Study of The Interaction of alfa Tocopherol and alfa Tocopheryl Acetate with Phospholipid bilayers(Elsevier, 1997-08-11) Davies, J. Eric D.; AKYÜZ, SEVİM; 10127FTIR spectroscopy has been employed in order to investigate α-tocopherol (α-T) and α-tocopheryl acetate (α-TA) induced effects on the molecular organization of dimyristoyl-l-α-phosphatidylcholine (DMPC) bilayers, at various temperatures and concentrations. It was concluded that α-T interacts much more strongly than α-TA, indicating that α-T has a more polar location in the membrane than α-TA. The observed changes in the carbonyl and phosphate group vibrational modes of DMPC on addition of α-T or α-TA are discussedPublication Metadata only Vibrational spectroscopic and structural investigations of bioactive molecule Glycyl-Tyrosine (Gly-Tyr)(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2017-09) Çelik, Sefa; Özel, Ayşen E.; AKYÜZ, SEVİM; 110147; 10127; 110745This study investigated the conformational behavior of biological active molecule Glycyl-Tyrosine (Gly-Tyr) dipeptide and its dimers, by Boltzmann jump and DET calculations. The energy calculations on Gly-Tyr dipeptide as a function of side chain torsion angles enabled us to determine the preferred conformations. The most stable conformations obtained from the above process were further optimized by the DFT calculations. The geometry optimization and vibrational wavenumbers calculations of Gly-Tyr dipeptide were carried out with the Gaussian03 program by using density functional theory (DFF) with B3LYP functional and 6-31++G (d,p) basis set. The dimeric forms of the dipeptide were also formed and energetically preferred conformations of dimers were investigated using the same method and the same basis set. The results provided a good account of the role of the number and type of inter- or/and intramolecular H-bond interactions existing in the dialer and monomer forms of the dipeptides. The fundamental vibrational wavenumbers, IR and Raman intensities for the optimized structure of monomeric and dimeric forms of the dipeptide were calculated and compared with the experimental vibrational spectra of solid Gly-Tyr dipeptide. Vibrational assignment of the molecule was done using the potential energy distribution analysis. HOMO-LUMO energy has been used to elucidate the reasons for intra molecular charge transfer. (C) 2017 Elsevier B.V. All rights reserved.Publication Metadata only The Modification Of Na-Montmorillonite By Salts Of Fatty Acids: An Easy İntercalation Process(Elsevier Science Bv, Po Box 211, 1000 Ae Amsterdam, Netherlands, 2010-11-20) Önder, Emel; Ersoy, Sabri; SARIER, NİHAL; TR114920; TR10598; TR11772The organic modification of Na-montmorillonite (Na-MMT) clay by a reaction with the sodium salts of octadecanoic acid (SOD) and dodecanoic acid (SDD) was studied for the production of effectively intercalated and organophilic clays. The results of X-ray diffractometer (XRD) analysis reveal that the interlayer spacing of Na-MMT increased from 1.38 nm to 3.37-1.4-4 nm, 3.56-1.45 nm, 3.61-1.44 nm and 3.56-1.44 nm in the organoclays containing 393 mM SOD, 787 mM of SOD, 540 mM SDD and 1080 mM SOD, respectively. In the Fourier transform infrared spectrometer (FTIR) analyses, the stretching and bending vibrations of the hydroxyl groups of Na-MMT at 3619,3407 and 1634 cm(-1) 15 as well as the Si-O and Al-O vibrations of silica-alumina layers at 1039-534 cm(-1) 16 respond to the structural changes from hydrophilic to hydrophobic character. Thermogravimetric (TG) analyses results also suggest that the intercalation of SOD and SDD were achieved in the organoclays samples and the samples had permanent structural modifications, although they retained their inorganic character. The TEM-EDS and SEM results show that the SOD and SDD were well dispersed and intercalated throughout the interlayer spaces or adsorbed onto the clay surface. The suggested organic modification of Na-MMT is an easily applicable process in which the chemically stable, low cost and widely available SOD and SDD are used as intercalating agents. (C) 2010 Elsevier B.V. All rights reserved.Publication Metadata only Elemental and spectroscopic characterization of plasters from Fatih Mosque-Istanbul (Turkey) by combined micro-Raman, FTIR and EDXRF techniques(Pergamon-Elsevier Science Ltd, The Boulevard, Langford Lane, Kidlington, Oxford Ox5 1Gb, England, 2015-10-05) Güleç, Ahmet; AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANIL; 10127The characterization of the plasters and coloring agents of the wall paintings of Fatih Mosque have been performed using combined micro-Raman, FTIR and EDXRF techniques. The investigations show that the plaster used on the walls has mixed gypsum lime binders. Cinnabar {HgS}, lead red {Pb3O4} and hematite {alpha-Fe2O3} were identified in the red surfaces. Blue color is attributed to ultramarine blue {Na8-10Al6Si6O24S2-4}. Green color is assigned to mixtures of green earth, copper phthalocyanine {Cu(C32Cl16N8)} and brochantite {CuSO4 center dot 3Cu(OH)(2)}. Strontium yellow {SrCrO4} and zinc white {ZnO} were also used to ensure the color tone. The results provide a basis for future restoration of wall paints. (C) 2015 Elsevier B.V. All rights reserved.Publication Metadata only FTIR and EDXRF ınvestigations of the second generations of salt tolerant soybean mutants(2012-08) AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANIL; ATAK, ÇİMEN; ÇELİK, ÖZGE; 10127; 113987; 6653Publication Metadata only FT-IR, EDXRF analysis of the Mardin-Mazidag phosphate deposit of Turkey and relations between phosphate, uranium and fluorine(ASIAN JOURNAL OF CHEMISTRY, 11/100 RAJENDRA NAGAR, SECTOR 3,, SAHIBABAD 201 005, GHAZIABAD, INDIA, 2008-06) Çağlar, Hikmet; Çağlar, Nazan; AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANIL; TR111424; TR10127; TR114368; TR110809EDXRF and FT-IR spectral analyses of the composite sample of Mardin-Mazidag phosphate deposit, in which the main phosphate mineral has been known to be collophane and dahllite, were reported. Uranium, phosphate and fluorine contents of the 25 individual phosphate samples were analyzed by EDXRF (U and P) and wet chemical methods (F). Quadratic regression model were applied on the U, P and F analyses results, in order to show the interrelation between phosphate, uranium and fluorine contents.Publication Metadata only Investigations on Empire series postage stamps of Ottomans (printed 1880-1890) by vibrational spectroscopic and energy dispersive X-ray fluorescence techniques(Elsevier Science Bv, Po Box 211, 1000 AE Amsterdam, Netherlands, 2017-03) AKYÜZ, SEVİM; AKYÜZ, ZEKİ TANIL; 10127In this study Empire series of stamps, the first postage stamps of Ottomans (printed in 1880-1890) after the Ottoman Empire became a member of Universal Postal Union, have been analyzed for the first time, non-destructively, using Fourier-transform infrared (FTIR), Raman and energy dispersive X-ray fluorescence (EDXRF) spectrometry methods Lead chromate, Prussian blue, vermillion, calcium carbonate, gypsum, cellulose, and oil were identified. The merging of data coming from vibrational spectroscopy and EDXRF techniques has allowed the characterization of the pigments used on the surface of each stamp and dispersed between the paper fibers. Additionally, the paper of the stamps was also analyzed. (C) 2017 Elsevier B.V. All rights reserved.Publication Metadata only Enez Kazısından Çıkartılan Bazı Arkeolojik Seramik ve Killerin FTIR, Mikro-Raman, EDXRF, XRD ve Kemometrik Yöntemler ile Analizi(2019-09) Çelik, Sefa; E.Özel, Ayşen; Başaran, Sait; AKYÜZ, SEVİM; 10127; 110147; 110745Potteries are the most abundant findings among the archeological artifacts. These findings, whose main raw material is clay, give important information about the civilization, culture, technology and trade of that period. Clay minerals undergo chemical and structural changes during the firing; e.g. during thermal treatment the structural collapse due to loss of structural hydroxyls, transformation to different mineral structures due to reaction with calcite in the structure and phase changes. For this reason, investigation of the mineral structures of the ancient potteries gives information about the firing temperature and firing conditions. Since XRD provides information mineral phases only in crystalline state, in combination to XRD the FTIR and Raman spectroscopic investigations and the determination of elemental contents by EDXRF allow us to determine the firing- temperature and -conditions in more detail. In this study, pottery fragments belonging to 4th-6th century BC, excavated in Enez- Turkey, were analyzed by different analytical techniques, in comparison with those of the local clays unearthed during the excavations. The firing temperatures and firing conditions were estimated. The XRD analysis of the raw clay found in the excavation area showed that it contained montmorillonite, illite and muscovite. The comparative FTIR and micro-Raman spectroscopic, EDXRF and XRD analyzes of the terracotta remains allowed to determine the chemical and mineralogical contents of the ceramic fragments. Moreover, chemometric techniques were applied on FTIR results in order to determine similarities and dissimilarities between archaeological findings and to reveal the distinct groups. Principal component analysis and cluster analysis techniques were used.Publication Metadata only Optimization of Tissue Culture Media Inducing Essential Oil Production of Levander (Lavandula angustifolia)(2019-09) Tuman, C.Büşra; Ayan, Alp; MERİÇ, SİNAN; ATAK, ÇİMEN; 219257Aim of this study is to induce in Vitro tissue cultures of levander which produces essential oils which have medical and aromatic properties. Media requirements were investigated for germination, shoot induction and development, rooting, callus initiation and suspenson culture induction. 1 mg/L BAP supplemented MS media presented the highest germination rate by 64.7 % and 2 mg/L BAP supplemented MS media initiated shoot propagation by 95.6 %. For rooting, MS media is supplemented with various NAA and IBA concentrations. The highest rooting rate was observed in 1.25 mg/L IBA supplemented MS media by 60 %. For callus induction MS media was supplemented with various concentrations of IAA, BAP and 2,4-D. The most efficient callus induction media for further suspension culteres was determined as 2 mg/L 2,4-D and 2 mg/L BAP supplemented MS media by 66 %. Characteristic blue pigmentation in suspension cultures were also evaluated spectroscopically. IAA supplemented MS media increased pigmentation significantly.Essential oil contents of suspension cultures were purified by steam destilation method and chacterized by fourier trasport infra red (FTIR) spectroscopy.