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Articles 2611 - 2628 of 2628
Full-Text Articles in Physical Sciences and Mathematics
Investigation Of Adsorption Isotherms Used For Wool Dyeing By Aqueous Extraction Of Cehri Fruit (Fructus Rhamni Petiolari) And Dyeing Of Wool And Silk Accompanied By Various Mordants, A. Haluk Aydin, Fuat Güzel, Zeki Tez
Investigation Of Adsorption Isotherms Used For Wool Dyeing By Aqueous Extraction Of Cehri Fruit (Fructus Rhamni Petiolari) And Dyeing Of Wool And Silk Accompanied By Various Mordants, A. Haluk Aydin, Fuat Güzel, Zeki Tez
Turkish Journal of Chemistry
In this study, adsorption isotherms were obtained by processing wool with dyestuff solutions of different concentrations extracted from cehri fruit with water. These isotherms follow the Nernst equation; the Nernst constant was determined and interpreted. In addition, wool and silk fibres were dyed with the same dyestuff solution and various mordants. Colours having a high fastness which could be used on an industrial scale were produced.
The Effect Of Examination Stress On The Levels Of Zn^{2+}, Total Protein, Albumin In Serum And Carbonic Anhydrase Isoenzymes In Erythrocytes, Nazan Demi̇r, Yaşar Demi̇r, Ali Yildirim, Ö. İrfan Küfrevi̇oğlu, Ebubekir Bakan
The Effect Of Examination Stress On The Levels Of Zn^{2+}, Total Protein, Albumin In Serum And Carbonic Anhydrase Isoenzymes In Erythrocytes, Nazan Demi̇r, Yaşar Demi̇r, Ali Yildirim, Ö. İrfan Küfrevi̇oğlu, Ebubekir Bakan
Turkish Journal of Chemistry
In this study, the levels of Zn^{2+}, total protein and albumin in the serums of students with temporarily examination stress without any physical illnes were determined and the relationship between these values was evaluated. Furthermore, the change in the activity of carbonic anhydrase metaloenzyme with Zn^{2+} and in the rates of carbonic anhydrase I and carbonic anhydrase II were also investigated. With this aim, blood samples were taken from 100 students just before examination and from 20 control subjects. Zn^{2+} levels were determined enzymatically, while total protein and albumin assays were done with an autoanalyzer. Carbonic anhydrase activity was measured …
Synthesis Of 2,4-Dihydro-4-(2-Phenylethyl)-5-(Isomeric Pyridyl)-3h-1,2,4-Triazole-3-Thiones And Their Derivatives., Rashid Iqbal, Khosrow Zamani, Nasim H. Rama
Synthesis Of 2,4-Dihydro-4-(2-Phenylethyl)-5-(Isomeric Pyridyl)-3h-1,2,4-Triazole-3-Thiones And Their Derivatives., Rashid Iqbal, Khosrow Zamani, Nasim H. Rama
Turkish Journal of Chemistry
Intramolecular cyclization of the three isomeric 1,4-disubstituted thiosemicarbazides 3(a-c) in aqueous sodium hydroxide was attempted to obtain 2,4-dihydro-4-(2-phenylethyl)-5-(isomeric pyridyl)- 3H-1,2,4-triazole-3-thiones 4(a-c). Each of the three isolated triazoles was separately treated with benzyl chloride and with chloroacetic acid to furnish the corresponding benzylthio 5(a-c) and carboxymethylthio derivatives 6(a-c), respectively
Latex Supported Manganese(Iii) Porphyrin Catalysts For Oxidations Of Alkenes By Hydrogen Peroxide And {\It Tert-} Butyl Hydroperoxide In The Aqueous Medium, Hayrettin Türk
Turkish Journal of Chemistry
Cationic polymer latexes were prepared by emulsion copolymerization of vinylbenzyl chloride and divinylbenzene followed by quaternization with trimethylamine and used as catalyst supports for 5,10,15,20-tetrakis(2, 6-dichloro-3-sulfonatophenyl)porphinatomanganese(III) chloride and 5,10,15,20-tetra(4-sul- fonatophenyl)porphinatomanganese(III) chloride. The supported catalysts and water soluble analogues were used for oxidation of styrene, 1-decene and {\it cis}-cyclooctene by hydrogen peroxide and {\it tert}- butyl hydroperoxide in the aqueous phase. The oxidation of 1-decene and {\it cis}-cyclooctene failed. In the oxidation of styrene, the porphyrin catalysts in the latex were more active than in solution. The relative molar ratios of oxidant: styrene: Mn porphyrin were 1250: 750: 1, and about …
Structural Fusion Of Condensed Benzenoid Systems, Lemi Türker
Structural Fusion Of Condensed Benzenoid Systems, Lemi Türker
Turkish Journal of Chemistry
On the basis of ring topologies, some theorems for the structural fusion of condensed benzenoids are presented. It has been proved that the oddness or evenness of the fused system is dictated by the degree of fusion.
The Sterols Of Cyclamen Coum, Nurettin Yayli, Cemalettin Baltaci
The Sterols Of Cyclamen Coum, Nurettin Yayli, Cemalettin Baltaci
Turkish Journal of Chemistry
The structures of one major and three minor constituents of sterol fraction of the Cyclamen coum have been established as stigmasterol [(22E)- (24S)- 24-ethylcholesta-\Delta ^{5,22}-dien-\beta-ol] ({\bf 1}), Poriferasterol [22E)-(24R)-24-ethylcholesta-\Delta^{5,22}-dien-3\beta- ol] ({\bf 2}), stigma-or poriferasta-\Delta^{3,5,22} triene [(22E)-24 -ethylcholesta-\Delta^{3,5,22}-trien] ({\bf 3}) stigma-or poriferosta- \Delta^{3,5,7,22}-tetraene [(22E)-24-ethylcholesta-\Delta^{3,5,7,22}- tetraene] ({\bf 4}) by spectroscopic means (NMR, EI-MS and GC-MS).
An Unusual Zinc-Promoted Reductive Retro-Wagner-Meerwein Rearrangement, Yavuz Taşkesenli̇gi̇l, Metin Balci
An Unusual Zinc-Promoted Reductive Retro-Wagner-Meerwein Rearrangement, Yavuz Taşkesenli̇gi̇l, Metin Balci
Turkish Journal of Chemistry
Bromination and dehydrobromination of exocyclic olefin {\bf 8} resulted in the formation of bromomethylene compound {\bf 9} and Wagner-Meerwein rearrangement product {\bf 10}. The dehydrobromination of {\bf 10} with potassium {\it tert}-butoxide provided the corresponding bromomethyl compound {\bf 11} in high yield. Reaction of {\bf 11} with Zn-Cu couple in methanol afforded the methyl derivative {\bf 12} and the parent olefin {\bf 8}. The unusual formation mechanism of {\bf 8} has been discussed in term of a reductive retro-Wagner-Meerwein rearrangement.
A Novel And Stereospecific Synthesis Of Conduritol-E Via Cyclohexa-3,5-Diene-1,2-Diol, Ahmet Maras, Hasan Secen, Yasar Sütbeyaz, Metin Balci
A Novel And Stereospecific Synthesis Of Conduritol-E Via Cyclohexa-3,5-Diene-1,2-Diol, Ahmet Maras, Hasan Secen, Yasar Sütbeyaz, Metin Balci
Turkish Journal of Chemistry
Conduritol-E was synthesized starting from cyclohexa-3,5-diene-1,2-diol {\bf 1a} in six steps. Acetylation of the diol {\bf 1a} followed by bromination gave (2\alpha/1\beta, \,\, 3\beta, \,\, 4\beta)-1,2-dibromo-2,3- diacetoxy- 5-cyclohexene {\bf 3} as main product. KMnO_{4}-hydoxylation of the dibromide {\bf 3} followed by acetylation, Zn-elimination and hydrolysis afforded conduritol-E {\bf 5a}.
Study Of Interaction And Solubility Parameters Of Alkyl Methacrylate Polymers By Inverse Gas Chromatography, İsmet Kaya, Eyüp Özdemi̇r, Mehmet Coşkun
Study Of Interaction And Solubility Parameters Of Alkyl Methacrylate Polymers By Inverse Gas Chromatography, İsmet Kaya, Eyüp Özdemi̇r, Mehmet Coşkun
Turkish Journal of Chemistry
Flory-Huggins interaction parameters (\chi) and partial molar free energies of mixing (\DeltaG^{\infty}_1) have been determined by inverse gas chromatography (i.g.c.) at temperatures 413-443 K for alkanes, acetates, ketones, aromatics, THF and methanol to estimate the polymer solubility parameters (\delta_2) of PMMA, PEMA, PİBMA and Pt-BMA. Furthermore, weight fraction activity coefficients (\alpha_1/W_1)^{\infty} of probes were calculated at infinite dilution at 413-443 K.
The Epoxidation Of Oil Obtained From The Eastern Black Sea Fishes, Eyüp Özcan, Bahri Ülküseven
The Epoxidation Of Oil Obtained From The Eastern Black Sea Fishes, Eyüp Özcan, Bahri Ülküseven
Turkish Journal of Chemistry
In this study we have investigated the suitable reaction conditions for the epoxidation of the semi-refined fish oil obtained from the fishes of eastern Black Sea, with peracetic acid. Various oxidation mixtures to reach the highest epoxyd-oxygene amount have been tested mean while the effective factors were established. In order to establish some specifications of the epoxy-product. Iodine-, hydroxyl-indices and epoxyd-oxygene percents were determined. We've also tried to explain how some reaction conditions (mole ratio of acetic acid to double bond and temperature) influenced the epoxy-product.
Synthesis Of Optically Active Camphorsulphonylbenzimidazoles, Mashooda Hasan, Humaira Masood, Naeema Khan, M. Zia-Ul-Haq
Synthesis Of Optically Active Camphorsulphonylbenzimidazoles, Mashooda Hasan, Humaira Masood, Naeema Khan, M. Zia-Ul-Haq
Turkish Journal of Chemistry
The preparation of optically active camphorsulphonylbenzimidazole {(\bf 1)}, a mixture of regioisomeric 5-nitro- {\bf (2A)} and 6-nitro-{\bf (2B)} camphorsulphonylbenzimidazoles, 5-nitro-{\bf (3A)} and 6-nitro-{\bf (3B)} 2- methyl camphorsulphonylbenzimidazoles is described. In this study the structure of the purified camphorsulphonylbenzimidazoles {\bf 1, 2B, 3A} and {\bf 3B} was confirmed by their mass and ^{1}H NMR spectral analysis. The specific rotation of each pure compound is also reported.
Synthesis, Characterization And Formation Kinetics Of Sn(Ii) And (Iv)-Schiff Base Complexes, Yakup Baran, Birgül Erk
Synthesis, Characterization And Formation Kinetics Of Sn(Ii) And (Iv)-Schiff Base Complexes, Yakup Baran, Birgül Erk
Turkish Journal of Chemistry
The synthesis and characterization of Sn(II) and Sn(IV) complexes of nitrogen and oxygen ligands, {\it p}-dimethyl aminophenylenesalicyladimine ( DPS), N,N'phenylenebis(salicylaldimine)(PBS) and N, N'-triethylenetetramine bis (salicylaldimine)(TTS) are reported. The structure of free ligands and their tin complexes were determined by elemental analysis, ir and nmr measurements. The kinetics of formation of the complexes were studied by stopped-flow technique at several temperatures with \mu=0.100 M (NaClO_{ 4}). Activation parameters \Delta H^{\ast} and \Delta S^{\ast} were determined.
Voltammetric Determination Of Promethazine By Platinum And Glassy Carbon Electrodes, Bengi Uslu, İnci Bi̇ryol, Sibel A. Özkan, Zühre Şentürk
Voltammetric Determination Of Promethazine By Platinum And Glassy Carbon Electrodes, Bengi Uslu, İnci Bi̇ryol, Sibel A. Özkan, Zühre Şentürk
Turkish Journal of Chemistry
The electrochemical oxidation of promethazine was studied by linear sweep and cyclic voltammetry on platinum and glassy carbon electrodes. The dependence of current intensities and potentials on pH, concentration, scan rate and nature of the buffer was examined. Linear calibration plots were obtained in phosphate buffer (pH 7.0) and acetate buffer (pH 4.7) for platinum and glassy carbon electrode, respectively.
Chemistry Of Aerosol In Uludağ National Park, Serpil Y. Karakaş, Semra G. Tuncel
Chemistry Of Aerosol In Uludağ National Park, Serpil Y. Karakaş, Semra G. Tuncel
Turkish Journal of Chemistry
Chemical composition of aerosol samples which were collected daily during September 1993 - April 1994 was examined by determining the concentrations and variations of major ions in aerosol samples, determining the binary correlations and the sources of them. Sulfate made up the 30% of aerosol mass with an 2.14 \mug m^{-3} average concentration. Measured chemical parameters in Uludağ National Park were comparable with other rural area data expect Ca^{2+} which was higher in our station with an average concentration of 1.61 \mug m^{-3}. Ion balance showed a deficiency of acid forming anions (SO^{2-}_4 and NO^-_3 for about 30% on the …
Catalysis Of Autoxidation Of 2,6-Di-Tert-Butylphenol In Water By Metallophthalocyanine Tetrasulfonates Bound To Polyelectrolyte Supports, Yasemin Tura Kopkalli, Hayrettin Türk
Catalysis Of Autoxidation Of 2,6-Di-Tert-Butylphenol In Water By Metallophthalocyanine Tetrasulfonates Bound To Polyelectrolyte Supports, Yasemin Tura Kopkalli, Hayrettin Türk
Turkish Journal of Chemistry
2,6-and 2,10-Ionenes and soluble poly(vinylbenzyl)trimethylammonium chloride polyelectrolytes were synthesized and used as catalyst supports for cobalt-, iron- and copper-phthalocyanine tetrasulfonates on the autoxidation of 2,6-di-{\it tert}-butylphenol in water by molecular oxygen. Polyelectrolyte supported cobalt-phthalocyanine tetrasulfonate showed the highest activity in comparison with the supported analogous of iron- and copper-phthalocyanine tetrasulfonates. The supported metallophthalocyanine tetrasulfonates had better catalytic activities than the unsupported analogous for the reaction. The reaction yielded 3,3',5,5'-tetra-tert-butyl- 4,4'-diphenoquinone as the only oxidation product of 2,6-di-tert-butylphenol. The extent of the reaction was affected by time, temperature, pH, the types and concentrations of supports and metallophthalocyanine tetrasulfonates.
Chelate Ring-Closure Kinetics Of Cr(Co)_5 (Dppm) Studied By ^{31}P-Nmr Spectroscopy, Saim Özkar, Ceyhan Kayran, Ayşin Tekkaya
Chelate Ring-Closure Kinetics Of Cr(Co)_5 (Dppm) Studied By ^{31}P-Nmr Spectroscopy, Saim Özkar, Ceyhan Kayran, Ayşin Tekkaya
Turkish Journal of Chemistry
^{31}P-NMR spectroscopy was used to study the kinetics of the chelate ring-closure reaction in CR(CO)_5 (DPPM) where DPPM is bis (diphenylphosphino) methane. DPPM is potentially a bidentate ligand, but in this complex it is coordinated to the transition metal in a monodentate fashion and therefore can undergo chelation. The thermal chelate ring-closure reaction was carried out in an NMR sample tube at a constant temperature and the course of the reaction was quantitatively followed by taking ^{31}P-NMR spectra in appropriate time intervals. Kinetic results have shown that the chelate ring-closure reaction of Cr(CO)_5 DPPM is of zero-order. Activation parameters were …
The Concept Of Molecular Similarity And The Angle Of Total \Pi-Electron Energy, Lemi Türker
The Concept Of Molecular Similarity And The Angle Of Total \Pi-Electron Energy, Lemi Türker
Turkish Journal of Chemistry
The concept of molecular similarity is developed and a novel similarity index based on the cosine of the angle of total \Pi-electron energy is proposed to interrelate structural variations to operant properties of molecules isoconjugate with alternant hydrocarbons.
Polyelectrolytes In Immunology: Fundametals And Perspectives, Mehmet I. Mustafaev
Polyelectrolytes In Immunology: Fundametals And Perspectives, Mehmet I. Mustafaev
Turkish Journal of Chemistry
Physico-chemical criteria for the construction of artifical immunomodulators and immunogens(and vaccines) on the basis of synthetic polyelectrolyte(PE) and polyelectrolyte complexes(PEC) with low molecular weight ligands and protein (and polysaccharide) antigens are considered. The role of electric charge, chain length, conformation, hydrophobicity, polydispersity and supramolecular structure in the immunomodulating activity of PE(PEC) and the conditions facilitating the transformation of their suppressor capacity into immunostimulating one in the same polymerhomologues series are discussed. A structure-function relationship of immunogenicity of PE(PEC), a structural model of an artificial polymer- subunit immunogen and some practical applications of them as valuable tools in theoretical immunological studies …