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2010

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Articles 15061 - 15090 of 16045

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Synthesis And Characterisations Of Some New 2,4-Dihydro-[1,2,4]- Triazol-3-One Derivatives And X-Ray Crystal Structures Of 4-(3-Phenylallylideneamino)-5-Thiophen-2-Yl-Methyl-2,4-Dihydro-[1,2,4]Triazol-3-One, Kemal Sancak, Yasemi̇n Ünver, Canan Kazak, Esra Düğdü, Burcu Arslan Jan 2010

Synthesis And Characterisations Of Some New 2,4-Dihydro-[1,2,4]- Triazol-3-One Derivatives And X-Ray Crystal Structures Of 4-(3-Phenylallylideneamino)-5-Thiophen-2-Yl-Methyl-2,4-Dihydro-[1,2,4]Triazol-3-One, Kemal Sancak, Yasemi̇n Ünver, Canan Kazak, Esra Düğdü, Burcu Arslan

Turkish Journal of Chemistry

Compounds 2 were synthesised via the reaction of 4-amino-5-thiophen-2-yl-methyl-2,4-dihydro-[1,2,4]-triazol-3-one (1) with aldehydes. Compounds 3 and 4 were obtained from compounds 2 with bromo acetophenone and ethyl bromoacetate, respectively. The synthesis of compounds 2, 3, and 4 and crystal structure of compound 2a are being reported. The molecular structures were identified by IR, ^1H-NMR, ^{13}C-NMR, MS, and elemental analyses. Compound 2a crystallises in the monoclinic P 2_1/n space group, with a = 6.565(5) Å, b = 18.278(5) Å, c = 13.8166(18) Å, \beta = 96.227(5)°, V = 1553.6(14) Å^3, Z = 4. The newly compounds synthesised were screened for their antibacterial …

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Synthesis And Crystal Structure Of A Novel Multimodal Ligand, 6,6'-Bis(2-(Di(Pyridin-2-Yl)Methylene)-1-Methylhydrazinyl)-2,2'-Bipyridine, And Its Copper(I) Complex, {[Cu_3l_2](Pf_6)_3° 3h_2o} (1), Çağlar Ağaç, İsmai̇l Yilmaz, Abdurrahman Şengül, Simon J. Coles Jan 2010

Synthesis And Crystal Structure Of A Novel Multimodal Ligand, 6,6'-Bis(2-(Di(Pyridin-2-Yl)Methylene)-1-Methylhydrazinyl)-2,2'-Bipyridine, And Its Copper(I) Complex, {[Cu_3l_2](Pf_6)_3° 3h_2o} (1), Çağlar Ağaç, İsmai̇l Yilmaz, Abdurrahman Şengül, Simon J. Coles

Turkish Journal of Chemistry

The single crystal X-ray structure of the novel multimodal ligand 6,6'-bis(2-(di(pyridin-2-yl)methylene)-1-methylhydrazinyl)-2,2'-bipyridine, C_{34}H_{28}N_{10} (L), was determined at 120 (2) K. The ligand possesses a centre of symmetry that generates a planar bipyridyl core with the hydrazone substituents in a trans-geometry. The di-2-pyridyl moieties at either terminus of the molecule twist out of the plane (52.90 and 56.32 Å). The crystal structure comprises 2-dimensional ribbons that stack about each other so as to optimise van der Waals interactions and packing efficiency. Studies of the coordination properties of the novel multimodal ligand with copper(I) show that 2 ligand strands wrapped around the copper(I) …

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Convenient Synthesis And Anion Recognition Property Of Acylhydrazone-Based Molecular Tweezer Receptors, Hai-Xian Ren, Ming-Gen Zhao, Ying-Jin Wang Jan 2010

Convenient Synthesis And Anion Recognition Property Of Acylhydrazone-Based Molecular Tweezer Receptors, Hai-Xian Ren, Ming-Gen Zhao, Ying-Jin Wang

Turkish Journal of Chemistry

Three acylhydrazone-based compounds were designed as novel neutral sensors for anions, and synthesized by simple steps in good yields. Their anion recognition properties were studied by UV-vis and ^1H-NMR spectroscopy. The results showed that the receptors 1, 2, and 3 all had a better selectivity for F^- and CH_3COO^-, but no evident binding with Cl^-, Br^-, I^-, NO_3^-, H_2PO_{4}^-, or HSO_{4}^-. The results indicated that anion recognition was achieved via convergent hydrogen bond interactions from acylhydrazone functionality on the side arms. The UV-vis data indicated that a 1:1 stoichiometry complex was formed between compounds 1, 2, or 3 and anions. …

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A Novel Optical Membrane With Extended Detection Range Of Ph, Meissam Noroozifar, Mozhgan Khorasani Motlagh, Safeyeh Bahmanzadeh, Shokoofah Boroon Jan 2010

A Novel Optical Membrane With Extended Detection Range Of Ph, Meissam Noroozifar, Mozhgan Khorasani Motlagh, Safeyeh Bahmanzadeh, Shokoofah Boroon

Turkish Journal of Chemistry

A pH optical sensor was developed based on the use of a mixture of Malachite Green Oxalate and Bromocresol Green indicators immobilized in a triacetylcellulose membrane, which had been previously hydrolyzed. Requirements of the pH indicators were investigated, including the effects of the coupling pH, indicator ratio, and concentrations of the indicators. The pH sensor performed with a very fast response (10 s) and long term stability with no significant leaching of the dyes. The sensor had a linear response over a range of 6.6 pH units in the pH range between 0.4 and 7.0. A relative standard deviation of …

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Bromodimethylsulfonium Bromide/Tetrabutylammonium Nitrite: An Efficient Catalyst Mixture For The Nitration Of Phenols, Batool Akhlaghinia, Ali Reza Pourali Jan 2010

Bromodimethylsulfonium Bromide/Tetrabutylammonium Nitrite: An Efficient Catalyst Mixture For The Nitration Of Phenols, Batool Akhlaghinia, Ali Reza Pourali

Turkish Journal of Chemistry

Nitrophenols were obtained via direct nitration of phenols with tetrabutylammonium nitrite in the presence of bromodimethylsulfonium bromide at room temperature in high yields under aprotic conditions.

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Effect Of Various Substituents On Intramolecular 1,1-Vinylboration, Synthesis Of 1-Silacyclobutene Derivatives, Ezzat Khan, Bernd Wrackmeyer Jan 2010

Effect Of Various Substituents On Intramolecular 1,1-Vinylboration, Synthesis Of 1-Silacyclobutene Derivatives, Ezzat Khan, Bernd Wrackmeyer

Turkish Journal of Chemistry

The reaction of 1-boryl-1-alkenyl chlorosilane derivatives with alkynyllithium reagents [Li-C\equiv C-R^3 (R^3~=~Ph, SiMe_3)] at low temperature (--78 °C) affords alkenyl(alkyn-1-yl)silanes. These compounds are precursors of 1-silacyclobutene derivatives, which are formed via intramolecular 1,1-vinylboration. This reaction works for various groups at silicon (R^1/R^2: R^1 = H, Me, Ph; R^2 = Me, Ph) and at the C=C and C\equiv C units (R/R^3: R = ^nBu, Ph; R^3 = ^nBu, Ph, SiMe_3). The conversion into 1-silacyclobutene derivatives is incomplete only in the case of R^3 = SiMe_3. The reactions were monitored by NMR spectroscopy in order to elucidate the reaction mechanism, and the …

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Vapor Phase Alkylation Of Toluene Using Various Alcohols Over H3po4/Mcm-41 Catalyst: Influence Of Reaction Parameters On Vapor Phase Alkylation Of Toluene Using Various Alcohols Over H_3po_4/Mcm-41 Catalyst: Influence Of Reaction Parameters On Selectivity And Conversion, Alireza Abbaspourrad, Roozbeh Javadkalbasi, Farzad Zamani Jan 2010

Vapor Phase Alkylation Of Toluene Using Various Alcohols Over H3po4/Mcm-41 Catalyst: Influence Of Reaction Parameters On Vapor Phase Alkylation Of Toluene Using Various Alcohols Over H_3po_4/Mcm-41 Catalyst: Influence Of Reaction Parameters On Selectivity And Conversion, Alireza Abbaspourrad, Roozbeh Javadkalbasi, Farzad Zamani

Turkish Journal of Chemistry

A mesoporous MCM-41 molecular sieve material with a molar ratio of SiO_2/Al_2O_3 = 70 and loaded with H_3PO_4 was used as a catalyst for the alkylation of toluene, using various alcohols, namely methanol, iso-propanol, and tert-butanol, as alkylating agents. Para-alkylated toluene was the predominant product, formation of which was enhanced by moderate temperature, low amounts of the alkylating agents in the feed, and high carrier gas flow rate. Time on stream was found to exert a profound effect on the selectivity and conversion to the different products.

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Ethyl 5-Oxo-3-Arylamino-2,5-Dihydroisoxazole-4- Carboxylates As Sources Of Imidazopyrimidine And Aminoindole Derivatives, Ahmad Poursattar Marjani, Jabbar Khalafy Jan 2010

Ethyl 5-Oxo-3-Arylamino-2,5-Dihydroisoxazole-4- Carboxylates As Sources Of Imidazopyrimidine And Aminoindole Derivatives, Ahmad Poursattar Marjani, Jabbar Khalafy

Turkish Journal of Chemistry

The reaction of ethyl 5-oxo-3-arylamino-2,5-dihydroisoxazole-4- carboxylates with 2-chloropyrimidine and 2-chlorobenzoxazole gave the corresponding isoxazolones with pyrimidine and benzoxazole rings substituted on N-2. Their rearrangements with triethylamine in ethanol produced the corresponding imidazopyrimidine and aminoindole derivatives, respectively, through intramolecular cyclisation.

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Reactions Of 4-Benzoyl-1,5-Diphenyl-1h-Pyrazole-3- Carboxylic Acid Chloride With Various Hydroxylamines And Carbazates, Eli̇f Korkusuz, İsmai̇l Yildirim Jan 2010

Reactions Of 4-Benzoyl-1,5-Diphenyl-1h-Pyrazole-3- Carboxylic Acid Chloride With Various Hydroxylamines And Carbazates, Eli̇f Korkusuz, İsmai̇l Yildirim

Turkish Journal of Chemistry

The 1H-pyrazole-3-carboxylic acid 2 was converted via reactions of its acid chloride 3 with various hydroxylamine 4a-f and carbazate derivatives 8a-c into the corresponding novel N-substituted-4-benzoyl-1,5-dipenyl-1H-pyrazole-3-carboxamides 5a-c, N,N-disubstituted-4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carboxylates 6d,e, 4-benzoyl-N-{[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]oxy}- N-methyl-1,5dip- henyl-1H-pyrazole-3-carboxamide (7), and 4-benzoyl-N'-(alkoxycarbonyl)-1,5-diphenyl-1H-pyrazole-3-car- bohydrazides 9a,b and 10, respectively, in good yields (65\%-90\%). The reactions of 3 with 4 and 8 in xylene for 8-15 h with catalytic amounts of base led to the formation of the products 5-7, 9, and 10. The structures of all new synthesized compounds were established by the ^{13}C-NMR, ^1H-NMR, IR spectroscopic data, and elemental analyses.

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An Efficient And Green Approach For The Synthesis Of Vinyl Aryl Ethers In The Presence Of Guanidine Hydrochloride, Seyed Mohammad Vahdat, Robabeh Baharfar Jan 2010

An Efficient And Green Approach For The Synthesis Of Vinyl Aryl Ethers In The Presence Of Guanidine Hydrochloride, Seyed Mohammad Vahdat, Robabeh Baharfar

Turkish Journal of Chemistry

A stereoselective procedure for vinyl aryl ether bond formation by direct coupling of dialkyl acetylenedicarboxylates and substituted phenols or naphthols under mild reaction conditions has been developed. Using guanidine hydrochloride as a new catalyst and water-acetone as green solvent, dialkyl acetylenedicarboxylates were reacted with substituted phenols or naphthols in room temperature to produce vinyl aryl ethers in good to excellent yields.

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Synthesis And Surfactant Properties Of N-Acylation Compounds Derived From Hydrolysis Degradation Products Of N-(\Beta-Cianoethyl)-\Epsilon-Caprolactam, Andreea Bondarev Jan 2010

Synthesis And Surfactant Properties Of N-Acylation Compounds Derived From Hydrolysis Degradation Products Of N-(\Beta-Cianoethyl)-\Epsilon-Caprolactam, Andreea Bondarev

Turkish Journal of Chemistry

N-acyl amino acids can be used as active surface agents in the detergents industry, as well as in the pharmaceutical industry and cosmetics. Properties of these compounds are superior to those of fatty acids soaps and they are not toxic to the environment and have low Kraft points, because of peptide bonds (CO-NH). Acylation at the nitrogen atom can be performed with good yields without catalysts, for strong nucleophilic derivatives. The synthesis of some derivatives of 4-azasebacic acid, which are hydrolysis degradation products from N-(\beta -cianoethyl)-\epsilon -caprolactam, has been described and the N-acylation processes for these compounds are also presented. …

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Synthesis And Characterization Of Ba/Mcm-41, Emi̇ne Kaya, Nuray Oktar, Gürkan Karakaş, Kirali̇ Mürtezaoğlu Jan 2010

Synthesis And Characterization Of Ba/Mcm-41, Emi̇ne Kaya, Nuray Oktar, Gürkan Karakaş, Kirali̇ Mürtezaoğlu

Turkish Journal of Chemistry

Mesoporous Ba/MCM-41 type materials (Ba/MCM-41) with high Ba/Si molar ratios between 0.025 and 0.1 were synthesized by direct hydrothermal synthesis. The samples were characterized by XRD, nitrogen adsorption, TGA-DTA, FTIR, SEM-EDS, and TEM techniques. BET surface areas of samples with various Ba loadings were found between 722 and 931 m^2/g with 28 Å average pore size, which is consistent with the pore size of 30 Å for pure MCM-41 samples synthesized by the same procedure. The crystal structures of synthesized MCM-41 and Ba/MCM-41 were confirmed by XRD analysis. Among the investigated Ba/MCM-41 samples, the formation of barium oxide and barium …

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Computational Study On Nitronium Squarate - Potential Oxidizers For Solid Rocket Propulsion?, Eli̇f Gökçinar, Thomas Klapötke Jan 2010

Computational Study On Nitronium Squarate - Potential Oxidizers For Solid Rocket Propulsion?, Eli̇f Gökçinar, Thomas Klapötke

Turkish Journal of Chemistry

The enthalpies of formation for solid ionic nitronium squarate, [NO_2]_2[C_4O_4], and covalent squaric acid dinitrate ester, O_2N-C_4O_4-NO_2, were calculated using the complete basis set (CBS-4M) method of Petersson and coworkers in order to obtain very accurate energies. The covalent form (O_2N-C_4O_4-NO_2) was identified as the more stable isomer. The combustion parameters with respect to possible use as ingredients in solid rocket motors for both stable species were calculated using the EXPLO5 code. The performance of an aluminized formulation with covalently bound dinitrate ester (O_2N-C_4O_4-NO_2) was shown to be comparable to that of ammonium perchlorate/aluminum. This makes squaric acid dinitrate ester …

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Comparative Essential Oil Analysis Of Geranium Sylvaticum Extracted By Hydrodistillation And Microwave Distillation, Nuran Kahri̇man, Gonca Tosun, Hasan Genç, Nuretti̇n Yayli Jan 2010

Comparative Essential Oil Analysis Of Geranium Sylvaticum Extracted By Hydrodistillation And Microwave Distillation, Nuran Kahri̇man, Gonca Tosun, Hasan Genç, Nuretti̇n Yayli

Turkish Journal of Chemistry

The essential oil of Geranium sylvaticum L. (Geraniaceae) was isolated by hydrodistillation (HD) and microwave distillation (MD). The composition of the volatile oils was characterized by GC-FID and GC-MS. A total of 73 and 70 compounds were identified, constituting over 90.3% and 98.7% of oil composition of G. sylvaticum, respectively. Sesquiterpene hydrocarbons were shown to be the main group of constituents (HD: 31.7% and MD: 39.8%). The major component of the oils of G. sylvaticum was \gamma -muurolene (HD: 10.9% and MD: 19.6%). The comparative study showed that the amount of total volatiles (98.7%) and the major constituent (39.8%) were …

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Quantum Chemical Studies On Tautomerism And Basicity Behavior Of Some 1,2,4-Triazole Derivatives, Cemi̇l Öğreti̇r, Yadi̇gar Gülseven Sidir, İsa Sidir, Erol Taşal Jan 2010

Quantum Chemical Studies On Tautomerism And Basicity Behavior Of Some 1,2,4-Triazole Derivatives, Cemi̇l Öğreti̇r, Yadi̇gar Gülseven Sidir, İsa Sidir, Erol Taşal

Turkish Journal of Chemistry

The acidity constants, relative stabilities, and tautomeric equilibrium constants of some 1,2,4-triazole derivatives were determined using the density functional theory (DFT) with the B3LYP method and 6-311G(d,p) basis set. The integral equation formalism version of the polarizable continuum model (IEFPCM) was used in the calculations of the aqueous phase. The calculated tautomeric equilibrium and relative stabilities values revealed that the 4H-1,2,4 triazole form for all studied molecules was favored over the 1H-1,2,4 triazole form. Protonation processes indicated the predominance of the 1H-1,2,4 triazole form over the 2H-1,2,4 triazole form. The correlation attempt between the experimental and the calculated acidity constants, …

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Weak Shear Study Of Galaxy Clusters By Simulated Gravitational Lensing, David Coss Jan 2010

Weak Shear Study Of Galaxy Clusters By Simulated Gravitational Lensing, David Coss

Doctoral Dissertations

"Gravitational lensing has been simulated for numerical galaxy clusters in order to characterize the effects of substructure and shape variations of dark matter halos on the weak lensing properties of clusters. In order to analyze realistic galaxy clusters, 6 high-resolution Adaptive Refinement Tree N-body simulations of clusters with hydrodynamics are used, in addition to a simulation of one group undergoing a merger. For each cluster, the three-dimensional particle distribution is projected perpendicular to three orthogonal lines of sight, providing 21 projected mass density maps. The clusters have representative concentration and mass values for clusters in the concordance cosmology. Two gravitational …

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Study Of Catalytic Activities Of Nanostructure Copper And Cobalt Supported Zsm-5 Catalysts For Conversion Of Volatile Organic Compounds, Aligholi Niaei, Dariush Salari, Seyed Ali Hosseini Jan 2010

Study Of Catalytic Activities Of Nanostructure Copper And Cobalt Supported Zsm-5 Catalysts For Conversion Of Volatile Organic Compounds, Aligholi Niaei, Dariush Salari, Seyed Ali Hosseini

Turkish Journal of Chemistry

This paper reports the comparison of the activities of nanostructure Cu-ZSM-5 and Co-ZSM-5 catalysts for conversion of ethyl acetate and toluene and deals with the relationship between activity and structure of catalysts. The catalysts were characterized by ICP-AES, XPS, EDX, XRD, SEM, and TEM techniques. Catalytic studies were carried out under atmospheric pressure and in a temperature range of 200-500 °C. Cu-ZSM-5 catalysts showed better activity than Co-ZSM-5, revealing higher activity of copper cations. The higher activity was ascribed to higher electro-negativity, smaller cation radius, good distribution, and specific coordination of copper cations inside Cu-ZSM-5 catalysts. The activity of catalysts …

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Electro-Oxidation Of Some Non-Steroidal Anti-Inflammatory Drugs On An Alumina Nanoparticle-Modified Glassy Carbon Electrode, Mahla Tabeshnia, Hossein Heli, Ali Jabbari, Ali A. Moosavi-Movahedi Jan 2010

Electro-Oxidation Of Some Non-Steroidal Anti-Inflammatory Drugs On An Alumina Nanoparticle-Modified Glassy Carbon Electrode, Mahla Tabeshnia, Hossein Heli, Ali Jabbari, Ali A. Moosavi-Movahedi

Turkish Journal of Chemistry

The electro-oxidation of mefenamic acid, diclofenac, and indomethacin on glassy carbon and alumina nanoparticle-modified glassy carbon electrodes in a phosphate buffer solution at physiological pH was studied. The techniques of cyclic voltammetry, chronoamperometry, impedance spectroscopy, and steady state polarization measurements were applied. The drugs were irreversibly oxidized on bath electrodes via an anodic peak and the process was controlled by diffusion in the bulk of solution. Alumina nanoparticles increased the oxidation current, and lowered the peak and onset potentials. As such, alumina nanoparticles had an electrocatalytic effect, both kinetically and thermodynamically. The kinetic parameters of heterogeneous electron transfer and diffusion …

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Synthesis, Characterization, And Application Of Nanoporous Materials Based On Silicon- Or Halogen-Containing Spiroketal And Spirothioketal Polymers, Hamada H. Abdel-Razik Jan 2010

Synthesis, Characterization, And Application Of Nanoporous Materials Based On Silicon- Or Halogen-Containing Spiroketal And Spirothioketal Polymers, Hamada H. Abdel-Razik

Turkish Journal of Chemistry

Organic microporous materials based on silicon-containing spiroketal and spirothioketal polymers were synthesized via a 1,3-dioxol-forming polymerization reaction between 1,1a,4,4a,5,5a,8, 8a-octahydro-2,3,6,7-tetra(trimethylsilyl)-9,10-anthraquinone and different types of polyol or polythiol. These silicon-containing polymers were subjected to bromination to yield bromine-containing polymers. The structures of the prepared polymers were confirmed by NMR spectroscopy and molecular mass measurements. Nitrogen adsorption/desorption isotherms of the prepared polymers showed that a large amount of nitrogen was adsorbed at low relative pressure, indicating microporosity. These polymers have BET surface areas in the range of 505-830 m^2 g^{-1}. These polymers were determined to be useful for pervaporation separation of phenol/water …

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Characterization Of Chitosan In Acetic Acid: Rheological And Thermal Studies, Esam A. El-Hafian, Elham S. Elgannoudi, Azizah Mainal, Abdul Haamid Bin Yahaya Jan 2010

Characterization Of Chitosan In Acetic Acid: Rheological And Thermal Studies, Esam A. El-Hafian, Elham S. Elgannoudi, Azizah Mainal, Abdul Haamid Bin Yahaya

Turkish Journal of Chemistry

This study examined the influence of temperature, concentration, shearing time, and storage time on the rheological properties, i.e. the dynamic viscosity and shear stress, as a function of shear rate of chitosan solubilized in weakly acid solutions. The results showed that shear thinning behavior (pseudoplastic non-Newtonian behavior) was pronounced at temperatures from 20 to 50 °C, but was more remarkable at lower temperature. In addition, the activation energy value derived from ln \eta vs. 1/T data was found to be 20.86 kJ mol^{-1}. When the effect of concentration was studied, the shear thinning behavior was pronounced at all concentrations. The …

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Cover And Contents Jan 2010

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.

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Density Functional Theory Investigation Of Electrophilic Addition Reaction Of Chlorine To Tricyclo[4.2.2.2^{2,5}]Dodeca-1,5-Diene, Rza Abbasoğlu, Ahmet Yaşar Jan 2010

Density Functional Theory Investigation Of Electrophilic Addition Reaction Of Chlorine To Tricyclo[4.2.2.2^{2,5}]Dodeca-1,5-Diene, Rza Abbasoğlu, Ahmet Yaşar

Turkish Journal of Chemistry

Potential energy surface (PES) of the tricyclo[4.2.2.2^{2,5}]dodeca- 1,5-diene (TCDD)-Cl_2 system was studied by B3LYP/6-311+G(d,p) method and the configurations [reactants, molecular charge-transfer (CT) complex, transition states (TS1 and TS2), intermediate (INT), and product (P)] corresponding to the stationary points (minima or saddle points) were determined. Initially, a molecular CT-complex forms between Cl_2 and TCDD. With a barrier of 22.362 kcal mol^{-1} the CT-complex can be activated to an intermediate (INT) with energy 14.682 kcal mol^{-1} higher than that of the CT-complex. The intermediate (INT) then transforms easily (barrier 5.102 kcal mol^{-1}) into the final, N-type product. Accompanying the breaking of the …

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Synthesis And Characterization Of New Optically Active Polyamides Containing 2-(4-Nitro-1,3-Dioxoisoindolin-2-Yl)Succinic Acid And Aromatic Diamines Via Direct Polycondensation, Khalil Faghihi, Morteza Absalar, Mohsen Hajibeygi Jan 2010

Synthesis And Characterization Of New Optically Active Polyamides Containing 2-(4-Nitro-1,3-Dioxoisoindolin-2-Yl)Succinic Acid And Aromatic Diamines Via Direct Polycondensation, Khalil Faghihi, Morteza Absalar, Mohsen Hajibeygi

Turkish Journal of Chemistry

A new class of optically active polyamides (PAs) (6a-e) having 4-nitro-1,3-dioxoisoindolin-2-yl pendent groups were prepared by direct polycondensation reaction of 2-(4-nitro-1,3-dioxoisoindolin-2-yl) succinic acid (4) with various aromatic diamines in a medium consisting of triphenyl phosphite, calcium chloride, pyridine, and N-methyl-2-pyrrolidone. The resulting new polymers were obtained in high yields with inherent viscosities ranging between 0.32 and 0.48 dL/g, and were characterized by elemental analysis, FT-IR spectroscopy, specific rotation, solubility tests, and thermogravimetric analysis techniques (TGA and DTG). Bulky pendent groups of the polymer chains disturb interchain and intrachain interactions and make these PAs readily soluble in polar organic solvents such …

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Radical Scavenging Potential Of Compounds Isolated From Vitex Agnus-Castus, . Azizuddin, Talat Makhmoor, Muhammad Iqbal Choudhary Jan 2010

Radical Scavenging Potential Of Compounds Isolated From Vitex Agnus-Castus, . Azizuddin, Talat Makhmoor, Muhammad Iqbal Choudhary

Turkish Journal of Chemistry

Nine secondary metabolites-artemetin (1), casticin (2), 3-hydroxy-5,6,7,4'-tetramethoxy flavone U(3), penduletin (4), p-hydroxybenzoic acid (5), methyl 3,4-dihydroxybenzoate (6), methyl isovanillate (7), vanillic acid (8), and 3,4-dihydroxybenzoic acid (9)-were isolated from a folkloric medicinal plant, Vitex agnus-castus. The structures of compounds 1-9 were identified using spectroscopic techniques. Compound 7 was isolated for the first time from this plant. These compounds were screened for their antioxidant activity. Compounds 6 and 9 exhibited significant activity against the DPPH free radical.

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Some Bioactive Organotin(Iv) Derivatives With 3,4-Dichlorophenylacetic Acid: Synthesis, Spectroscopic Properties, And X-Ray Structure Of [Sn_4(C_4h_9)_8(Oocch_2c_6h_3cl_2)_4o_2], Muhammad Adeel Saeed, Muhammad Khawar Rauf, . Imtiaz-Ud-Din, Amin Badshah, Muhammad Zaeem Akhtar, Bushra Mirza Jan 2010

Some Bioactive Organotin(Iv) Derivatives With 3,4-Dichlorophenylacetic Acid: Synthesis, Spectroscopic Properties, And X-Ray Structure Of [Sn_4(C_4h_9)_8(Oocch_2c_6h_3cl_2)_4o_2], Muhammad Adeel Saeed, Muhammad Khawar Rauf, . Imtiaz-Ud-Din, Amin Badshah, Muhammad Zaeem Akhtar, Bushra Mirza

Turkish Journal of Chemistry

Some bioactive organotin(IV) derivatives of 3,4-dichlorophenylacetic acid (HL) were synthesized by reacting the ligand acid with various di- or tri-organotin compounds (in suitable mole ratios) in the presence of triethylamine. The structural investigation was carried out via multinuclear (^1H, ^{13}C, and ^{119}Sn) NMR, IR spectroscopy, and X-ray crystallography. The crystal structure of 4 comprises a central Sn_2O_2 core with O atoms bonded to 2 dibutylbis(3,4-dichlorophenylacetato)tin(IV) units. All the Sn atoms of 4 are essentially 5-coordinated in distorted trigonal-bipyramidal geometry. Some of the compounds exhibited significant antibacterial and antifungal activity.

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Cellular Distribution Of Activity For Three Enzymes With Maltose Binding Protein As Fusion Partner And The Structural Implications, Özde F. Ütkür, Berna Sariyar Akbulut, Amable Hortaçsu Jan 2010

Cellular Distribution Of Activity For Three Enzymes With Maltose Binding Protein As Fusion Partner And The Structural Implications, Özde F. Ütkür, Berna Sariyar Akbulut, Amable Hortaçsu

Turkish Journal of Chemistry

The bacterial SEC pathway is commonly used for secretion of heterologous proteins in E. coli by fusing them to transported proteins to facilitate downstream processing. While some proteins are translocated very efficiently, some reside in the cytoplasm. In this work, maltose binding protein (MBP) was fused to 3 cytoplamic enzymes from Thermus thermophilus (serine protease, 251 residues; glucose isomerase, 381 residues; pullulanase, 718 residues) to study the protein transport from the cytoplasm by quantifying the distribution of activities in different cellular compartments. Pullulanase activity was harvested exclusively in the periplasm; however, glucose isomerase activity was harvested exclusively in the cytoplasm. …

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Synthesis Of Some Pyridazine Derivatives Carrying Urea, Thiourea, And Sulfonamide Moieties And Their Antimicrobial Activity, Deni̇z S. Doğruer, Şölen Urlu, Ti̇jen Önkol, Berri̇n Özçeli̇k, M. Fethi̇ Şahi̇n Jan 2010

Synthesis Of Some Pyridazine Derivatives Carrying Urea, Thiourea, And Sulfonamide Moieties And Their Antimicrobial Activity, Deni̇z S. Doğruer, Şölen Urlu, Ti̇jen Önkol, Berri̇n Özçeli̇k, M. Fethi̇ Şahi̇n

Turkish Journal of Chemistry

Some pyridazine derivatives carrying urea, thiourea, and sulfonamide groups were synthesized and evaluated for their antimicrobial activity against gram-positive and gram-negative bacteria, and fungi by using broth microdilution. The structures of these new compounds were confirmed by ^1H-NMR, mass spectrum, and elemental analysis. The synthesized compounds exhibited generally promising inhibitory activity against S. aureus (MIC ranging from 2 to 4 \mu g/mL) and E. coli (MIC ranging from 4 to 16 \mu g/mL). Moreover, all compounds showed antifungal activity against both C. albicans and C. parapsilosis, with a MIC value of 8 \mu g/mL.

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Scalable Multi-Modal Avatar Interface For Multi-User Environments, Brian Mac Namee, Mark Dunne, John D. Kelleher Jan 2010

Scalable Multi-Modal Avatar Interface For Multi-User Environments, Brian Mac Namee, Mark Dunne, John D. Kelleher

Conference papers

This research outlines an Intelligent Virtual Agent (IVA) interface, where multiple users will be able to interact with 3D avatars. This will take place in a distributed multi-modal environ- ment where the LOK8 Avatar System (AS) will need to locate it’s users from a crowd, using face tracking and novel 3D animation techniques.

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Exploring The Frontier Of Uncertainty Space, Rong Hu, Patrick Lindstrom, Sarah Jane Delany, Brian Mac Namee Jan 2010

Exploring The Frontier Of Uncertainty Space, Rong Hu, Patrick Lindstrom, Sarah Jane Delany, Brian Mac Namee

Conference papers

We aim to investigate methods balancing exploitation with exploration in active learning to improve the performance of uncertainty sampling. Two exploration guided sampling methods are compared to uncertainty sampling on various real-life datasets from the 2010 Active Learning Challenge. Our initial experiments seems to indicate that combining exploration with uncertainty sampling improves performance on certain datasets but not all.

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A Two Degrees-Of-Freedom (Dof) Scanning Micromirror Using Thermocapillary Effect In Microdroplets, Rakesh Dhull Jan 2010

A Two Degrees-Of-Freedom (Dof) Scanning Micromirror Using Thermocapillary Effect In Microdroplets, Rakesh Dhull

Theses

This thesis research proposes a novel and simple means of tilting micromirror on a microdroplet by utilizing thermocapillary actuated droplet deformation. Device theory, device design, fabrication, packaging, testing and results are discussed to demonstrate the operation of a 2-degrees-of-freedom (2- DOF) scanning micromirror. Thermocapillary, or Marangoni, effect and contact angle hysteresis are employed to control the droplet shape and position. Hysteresis in different liquids is studied with its influence on the stability of the droplet. The device consists of a micromirror placed onto a microdroplet, and can produce a 6.5° tilting angle when actuated at 30 V. The tilting angle …

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