Communications, Series B: Chemistry and Chemical Engineering

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    Gas chromatographic analysis of PS, PI, SPH and LPC fatty acids in red blood cell membrane of rat, rabbit, human and dog
    (2003) Dermiş, Saadet; Doğru, Bilgehan
    Fatty acid analysis of red blood cell (RBC) membrane PS, PI, LPC and SPH were examined in species like rat, human, dog and rabbit by GC. C16:0 and C18:0 were the prominent SFA (saturated fatty acids) in species phospholipids studied. C16:0 was higher in LPC and SPH whereas C18:0 was higher in PS and PI in all species and in dog LPC. Although evenly spread in phospholipids, MUFA (monounsaturated fatty acid) in PS, PI and LPC seamed to be higher than in SPH. Among MUFA C16:1 and C18:1 were the prominent ones in the species, C18:1 being considerably higher than C16:1. PUFAs (polyunsaturated fatty acids) were relatively high in PS and PI compared to LPC and SPH in each species. Arachidonate was one of the most abundant fatty acids in human, rat and dog. Rabbit possessed very low levels of arachidonate in each phospholipid compared to that of other species phospholipids. By contrast linoleic acid was high in rabbit RBC membrane phospholipids. While C18:2 , C20:4 and C22:6 were the major PUFAs of human RBC membrane phospholipids studied, C18:2 and C20:4 were the major ones in the others. 22-Carbon fatty acids were present in small amounts in most species. C22:6 was present in rabbit, rat and human RBC membrane phospholipids but very little was present in dog.
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    Probıng The Structure-Corrosıon Inhıbıtıon Property Relatıonshıp Of Pyrrole Olıgomers Wıth Dft Calculatıons
    (Ankara Üniversitesi Fen Fakültesi, 2019-12-31) Gece, Gökhan; Bilgiç, Semra; Kimya; Fen Fakültesi
    Density functional theory (DFT) calculations on pyrrole oligomers were carried out at the B3LYP/6-311+G(d,p) level to search the relationship between the molecular structure and corrosion inhibition. The electronic properties such as the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) energy levels, energy gap (LUMO-HOMO) and dipole moment were computed. It was found that these electronic values can explain some features of the inhibition phenomena.
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    Synthesıs And Characterızatıon Of Pure Sılıca Powder From A K-Feldspar Sılıcate Ore For Industrıal Value Addıtıon
    (Ankara Üniversitesi Fen Fakültesi, 2019-12-31) AYINLA, Kuranga İ.; BABA, Alafara A.; PADHY, Subrat Ku.; ADIO, Oseni; ODELEYE, Kehinde A.; TRIPATHY, Bankim Ch.; Other; Other
    Nigeria is one of the African countries endowed with abundant varieties of solid mineral resources. Despite huge mineral abundance in all States of the Federation, these resources to boost the country’s economy, aid industrialization and revenue generation has been far less utilized. Thus, the utilization of a Nigerian k-feldspar ore containing an admixture of orthoclase (KAlSiO8 : 96-740-9031), albite (AlSiO8 : 96-940-0741) and quartz (SiO2 : 96-900-9667) impurities to produce pure silica powder (PSP) was investigated using roast-leaching and co-precipitation method. During leaching, parameters such as leachant concentration, effect of particle size and reaction temperature on the synthesis yield were accordingly examined. At optimal leaching conditions (2.0 mol/L NaOH, 90°C), 87% of the initial 10g/L ore reacted within 120 minutes. The un-reacted product (~13.0%) analyzed by XRD was found to contain siliceous impurities which could serve as a valuable by-product for some defined industries. The leachate at optimal leaching was accordingly co-precipitated using concentrated H2SO4 to obtain pure silica powder (PSP) of industrial value.
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    Determınatıon Of Absolute Confıguratıon Of 8,8,10,10tetrachloro-20,21-Dıhydro-18h,23h-6,12-Epıazeno-6λ5,8λ5,10λ5, 12λ5[1,3,2]Benzoxazaphosphonıno[2',3':8,9][1,3,5,7,9,2,4,6,8] Pentaazatetraphosphacycloundsyno[2,1-B][1,3,2] Benzoxazaphosphonıne Usıng X-Ray Crystallography
    (Ankara Üniversitesi Fen Fakültesi, 2019-12-31) Elmas, Gamze; Okumuş, Aytuğ; İsaoğlu, Satiye Sevim; Hökelek, Tuncer; Kılıç, Zeynel; Kimya; Fen Fakültesi
    The title compound, 8, 8, 10, 10-tetrachloro-20,21-dihydro-18H, 23H-6, 12epiazeno-6λ5, 8λ5, 10λ5, 12λ5-[1,3,2] benzoxazaphosphonino [2',3':8,9][1,3,5,7,9,2,4,6,8] pentaazatetraphosphacyclo undsyno [2,1-b] [1,3,2] benzoxazaphosphonine; C16H16Cl4N6O2P4, a cyclotetraphosphazene, has a tetrachloro-2, 4-spiro-ansa-spiro (tetrachloro-2,4-sas) architecture in which the bicyclic structure has consisted of eightmembered tetrameric N4P4 and seven-membered ansa (N1/P1/P1′/N4′/C8′/C8/N4) rings fused with a common PNP fragment. The asymmetric unit possesses one-half of the molecule. P1 and P1′ atoms are stereogenic centres. In addition, there is a mirror plane passing through the N3 and N1 atoms in the molecule, and therefore, this compound is in meso form (RS/SR). According to the checkcif result, it is found that the absolute configuration of P1 and/or P1′ phosphorus centers is RS, displaying that in the solid-state there is only one enantiomer in the unit cell. The space group is P bnm with cell parameters of a = 6.2692(2), b = 15.8111(3), c = 22.9393(4) Å.
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    Dft Calculatıons Of Benzoısoxazole Derıvatıves
    (Ankara Üniversitesi Fen Fakültesi, 2019-12-31) Özen, Ezgi; Kalkan, Melike; Civcir, Pervin Ünal; Kimya; Fen Fakültesi
    In this work, we carried out theoretical calculations to determine the structureactivity relationship and the properties of two benzoisoxazole derivatives. For the quantum chemical calculations, the Density Functional Theory (DFT) with B3LYP (Becke threeparameter hybrid correlation functional combined with Lee–Yang–Parr correlation functional) and 6-311+G(d,p) basis set were employed both in the gas phase and in different solvents such as toluene, chloroform, THF, DCM, acetone, DMSO. The CPCM (conductorlike polarizable continuum) solvation model was also used to compute condensed-phase energies in solvent systems. The structural parameters (bond lengths, bond angles, and dihedral angles), energetics (the total energies, the zero-point vibrational energies, the frontier orbital energies (EHOMO, ELUMO), and the bandgap energies) and the spectroscopic characteristics (UV, IR, 1H-NMR, and 13C-NMR) of the target molecules were also determined. The results of the calculations were compared with experimental values for molecule 1, which exists in literature. The calculated geometries (bond length, bond angle and dihedral angle) were in a good agreement with the experimental data. In the case of IR frequencies, the scaled calculated frequencies agreed reasonably well with the experimental results. Moreover, there is a good correlation between experimental and calculated proton signals (R² = 0.9769) and carbon signals (R² = 0.9972) of molecule 1.
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    Desıgnatıon Of Absolute Confıguratıon Of Multıhetereocyclıc 9,13-Dıchloro-22,22-Dıpyrrolıdıne-1-Yl1h,2h,13h,19h-9,13-(Epıazenophosphazeno)-9λ5,11λ5,13λ5-[1,3,5,2,4] Benzoxadıazadiphosphonıno[4',5':2,3][1,3,2]Dıazaphospholo[2,1-D] [1,3,5,2,4]Benzoxadıazadıphosphonıne By X-Ray Crystallographıc Data
    (Ankara Üniversitesi Fen Fakültesi, 2019-12-31) Elmas, Gamze; Okumuş, Aytuğ; İsaoğlu, Satiye Sevim; Hökelek, Tuncer; Kılıç, Zeynel; Kimya; Fen Fakültesi
    The title compound, 9,13-dichloro-22,22-dipyrrolidine-1-yl-1H,2H,13H,19H-9,13-(epiazenophosphazeno)-9λ5,11λ5,13λ5-1,3,5,2,4]benzoxadiazadiphosphonino [4',5':2,3][1,3,2]diazaphospholo[2,1-d][1,3,5,2,4]benzoxadiazadiphosphonine; 2(C24H32Cl2N8O2P4). 0.5 C6H12, a cyclotetraphosphazene derivative, has a geminaldipyrrolidino-2-trans-6-dichloro-ansa-spiro-ansa (gem-dipyrrolidino-2-trans-6-dichloroasa) structure in which the tricyclic parts are consisted of three eight-membered rings, containing a tetrameric N4P4 and two ansa rings. However, all these rings are not planar. The asymmetric unit contains two crystallographically independent molecules and one half of the cyclohexane solvent molecule. In both molecules, it is expected that two P (P1 and P3/P1′ and P3′) atoms are stereogenic centres. Both gem-dipyrrolidino-2-trans-6-dichloro-asa molecules have trans structures according to the Cl atoms, and they are in the racemic forms. Besides, it is found that the absolute configurations of P1, P3 and P1′, P3′ phosphorus centers are RR and SS, respectively. The title compound has P-1 space group, a Sohncke chiral space group, with the cell parameters of a = 9.6682(2), b = 13.8587(3), c = 24.0250(4) Å, � =105.249(2)°, � = 96.298(3)° and � = 98.367(3)°.
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    The inhıbitor effects of cannabis sativa l. Extracts on the corrosion of aluminium in h2so4 solutions
    (Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Yanardağ, Turan; Bayraktar, Nilgün; Yanardağ, Yağmur Kahraman; Özgen, Yasin; Aksut, A. A.; Kimya; Fen Fakültesi
    The aim of study was to investigate the effect of terpenoids in cannabis (Cannabis sativa L.) obtained from Diyarbakır line as corrosion agent on the corrosion of aluminum. Corrosion protection of aluminum (99.9% purity) with cannabis plant has been investigated using electrochemical methods. The methods with electrochemical impedance spectroscopy (EIS) and current potential showed that the plant has a potential to prevent corrosion of aluminum at 298 K in 0.5 M H2SO4 solution around 98%. The experimental results indicated that the cannabis plant can be used as an environmentally friendly inhibitor for aluminum.
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    Iron-Catalyzed Aryl Selectıve Acylatıon Of Mıxed Dıorganozıncs
    (Ankara Üniversitesi Fen Fakültesi, 2020-06-30) Pekel, Özgün Öner; Kahya, N. Didem; Kimya; Fen Fakültesi
    Iron-catalyzed acylation of mixed alkylarylzincs with aromatic acyl halides in THF provides a new route for aryl-aroyl coupling. This procedure is an atom-economic supplement to transition metal-catalyzed acylation of diorganozincs.
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    Synthesıs And Characterızatıon Of Mcm-41 And Metal-Supported Mcm-41 Materıals Usıng Dıfferent Methods
    (Ankara Üniversitesi Fen Fakültesi, 2020-12-31) Gedikli, Ümran; Mısıroğlu, Zarife; Bozkurt, Pınar Acar; Caner, Ahmet Muammer; Kimya; Fen Fakültesi
    One of the known groups of mesoporous materials is MCM-41 that has been applied as catalyst for various chemical reactions. In the content of this study, using cetylytrimethylammonium bromide (CTAB) as surfactant, sodium silicate and tetraethylortosilicate (TEOS) as silica source mesoporous materials MCM-41 was synthesized by hydrothermal synthesis method and sonochemical synthesis method. The obtained results showed that MCM-41 synthesized by the sonochemical method had higher specific surface area and pore volume than those synthesized by the hydrothermal method. Also, the effects of silica source on the distribution of products were studied and sodium silicate was found to be more suitable for the synthesis of MCM-41. Based on determinated optimum conditions, MCM-41 supported Al, Co and Fe having different ratios of metal (Metal/Si: ratio 0.05, 0.1 and 0.2) was synthesized. It was observed that metal dispersion on MCM-41 was homogenous for all samples and its particles sizes were between 10 nm to 30 nm. Synthesized mesoporous materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS) and Brunauer Emmett Teller (BET) surface area methods.
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    Evaluation study on the sequential extraction and eco-toxicological profile of heavy metals in sediment along the coastline of Nigeria
    (Ankara Üniversitesi Mühendislik Fakültesi, 2021) Akinnawo, Solomon; Other; Other
    Evaluation study of sediment samples collected from the coastline of Nigeria was investigated in order to assess the ecological impact of anthropogenic activities in the studied area. Sequential extraction, digestion and quantification were done using standard methods. The eco-toxicological assessment of heavy metals was performed using risk assessment indices, sediment quality guideline, fractionation study and total concentration of heavy metals. The risk assessment indices revealed that amid the analyzed heavy metals, Cu has the least probability of been toxic to the environment, however the fractionation study revealed that the mobility and bioavailability of the heavy metals followed the order: Cr ˃ Cd ˃ Pb ˃ Ni ˃ Cu. The sediment quality guidelines posited the analyzed heavy metals to be 8% toxic to the environment. Finally, the total concentration of heavy metals fell below the maximum permissible limit of USEPA.
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    Adsorption of neutral red dye from aqueous solutions by natural adsorbent: an equilibrium, kinetic and thermodynamic study
    (Ankara Üniversitesi Mühendislik Fakültesi, 2021) Kul, Ali Rıza; Other; Other
    This study investigates the adsorption of neutral red (NR) on the natural clayey material of Adilcevaz/ Bitlis located the northwest of Van Lake in Eastern Anatolia (Turkey). The adsorbent used was characterized by XRD, XRF, FTIR, SEM and TG-DTA analyzes. The effect of various parameters such as pH, contact time, initial concentration and temperature on NR removal was investigated using a batch process to optimize the maximum adsorption conditions. Equilibrium data for NR adsorption were analyzed using nonlinear two-parameter isotherms such as Langmuir, Freundlich, Dubinin-Radushkevich, and Tempkin, and three-parameter isotherm models, such as nonlinear Redlich-Peterson, Sips, and Koble-Corrigan. The modelling results showed that it was best adapted to the Freundlich isotherm model for the NR dye, with relatively higher R2 values and smaller S.E. The maximum adsorption capacity obtained from the experimental data was determined to be 4.2810 mg g-1. The adsorption process follows pseudo-second-order kinetics with a rate constant of 0.0110 g mg-1 min-1. The thermodynamic parameters indicate that a physical mechanism controls the NR adsorption on the natural clay and spontaneously occurs.
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    Plant extracts as corrosion inhibitors for aluminium in acidic environments-Review I
    (Ankara Üniversitesi Mühendislik Fakültesi, 2022) Bilgiç, Semra; Kimya; Fen Fakültesi
    The use of plant extracts as inhibitors in corrosive environments has been the subject of many studies in recent years. This review presents studies with various plant extracts used as inhibitors of the corrosion of aluminum in acidic environments.
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    A theoretical approach to the inhibitive effect of two new Schiff base compounds
    (Ankara Üniversitesi Mühendislik Fakültesi, 2022) Emregül, Kaan Cebesoy; Kimya; Fen Fakültesi
    The corrosion inhibition of mild steel was investigated using theoretical calculations in 2,2-[2,2-{2-hidroxy propane-1,3diyl}bis(oxy)bis(2,1-phenylene)]bis(methane-l-yl-l-ylidene ) bis(azan-l-yl-l-ylidene)diphenol (DF1) and 2,2-[2,2-{ethane-1,2diylbis(oxy)}bis(2,1-phenylene)]bis(methane-l-yl-l-ylidene)bis(azan-l-yl-l-yl-idene) diphenol (DF2). Various quantum chemical descriptors like EHOMO, ELUMO, ΔE, chemical hardness were calculated and discussed.
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    Untitled
    ARIFIEN, A. E.
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    Franck -Condon Principle and The Geometry of SCCI ' in the Excited Electronic State
    ABDEL -RAHMAN, A.;NOUR, E. M.;ABDELLA, M.H.;SAMY, E.
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