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2010

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Articles 8221 - 8250 of 8621

Full-Text Articles in Physical Sciences and Mathematics

Co(Iii) Catalysed Asymmetric Ring-Opening Of Epichlorohydrin By Salicylaldehyde Derivatives: Reversal Of Enantioselectivity And Rate Acceleration On Addition Of Alcl_3, Leman Karadeni̇z, Gamze Koz, Kadri̇ye Aydin, Stephen Thomas Astley Jan 2010

Co(Iii) Catalysed Asymmetric Ring-Opening Of Epichlorohydrin By Salicylaldehyde Derivatives: Reversal Of Enantioselectivity And Rate Acceleration On Addition Of Alcl_3, Leman Karadeni̇z, Gamze Koz, Kadri̇ye Aydin, Stephen Thomas Astley

Turkish Journal of Chemistry

Using asymmetric Cobalt(III) salen catalysts, the ring-opening of epichlorohydrin by 2,3-dihydroxybenzal- dehyde and 2,4- dihydroxybenzaldehyde was found to occur at the phenolic groups most distant from the aldehydic group. Switching catalysts afforded a reversal in enantioselectivity. For 2,3-dihydroxybenzaldehyde and salicylaldehyde, addition of AlCl_3 to the reaction mixture led to an increase in reaction rate without any decrease in product enantiopurity.

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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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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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Synthesis And Super-Swelling Behavior Of A Novel Low Salt-Sensitive Protein-Based Superabsorbent Hydrogel: Collagen-G-Poly(Amps), Mohammad Sadeghi, Hossein Hosseinzadeh Jan 2010

Synthesis And Super-Swelling Behavior Of A Novel Low Salt-Sensitive Protein-Based Superabsorbent Hydrogel: Collagen-G-Poly(Amps), Mohammad Sadeghi, Hossein Hosseinzadeh

Turkish Journal of Chemistry

Superabsorbent polymers are obtained by the graft copolymerization of 2-acrylamido-2-methylpropanesul- fonic acid (AMPS) monomer onto collagen, using ammonium persulfate as a free radical initiator in the presence of methylene bisacrylamide as a crosslinker. Infrared spectroscopy and TGA thermal analysis were carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy (SEM). The effect of reaction variables on swelling capacity was investigated to achieve a hydrogel with improved water absorbency. Under the optimized conditions concluded, maximum capacity of swelling in distilled water was found to be 268 g/g. The swelling …

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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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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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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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Electrochemical Impedance Spectroscopic Studies Of The Passive Layer On The Surface Of Copper As A Function Of Potential, Amtul Naseer, Athar Khan Jan 2010

Electrochemical Impedance Spectroscopic Studies Of The Passive Layer On The Surface Of Copper As A Function Of Potential, Amtul Naseer, Athar Khan

Turkish Journal of Chemistry

Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to investigate the oxide layer formed on a copper disc electrode and the changes that took place when treated potentiostatically in the range of -0.3 V to 0.9 V in buffer of pH 8.5. The response of an electrode using EIS, initially at equilibrium, to an applied potential was then modeled with equivalent circuits, proposed for different potential regions that completely illustrated the Cu/oxide/electrolyte systems and their properties in terms of 2 interfaces. Criterion for the applicability of equivalent circuit models was discussed. Changes in the film/metal interface as a …

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Chemical Composition And Antimicrobial Activity Of The Essential Oils Of Mosses (Tortula Muralis Hedw., Homalothecium Lutescens (Hedw.) H. Rob., Hypnum Cupressiforme Hedw., And Pohlia Nutans (Hedw.) Lindb.) From Turkey, Osman Üçüncü, Tayyi̇be Beyza Cansu, Turan Özdemi̇r, Şengül Alpay Karaoğlu, Nuretti̇n Yayli Jan 2010

Chemical Composition And Antimicrobial Activity Of The Essential Oils Of Mosses (Tortula Muralis Hedw., Homalothecium Lutescens (Hedw.) H. Rob., Hypnum Cupressiforme Hedw., And Pohlia Nutans (Hedw.) Lindb.) From Turkey, Osman Üçüncü, Tayyi̇be Beyza Cansu, Turan Özdemi̇r, Şengül Alpay Karaoğlu, Nuretti̇n Yayli

Turkish Journal of Chemistry

The essential oils of mosses [Tortula muralis Hedw. (Pottiaceae), Homalothecium lutescens (Hedw.) H. Rob. (Brachytheciaceae), Hypnum cupressiforme Hedw. (Hypnaceae), and Pohlia nutans (Hedw.) Lindb. (Mniaceae)] were investigated by means of GC-FID/MS techniques. The major components were nonanal (18.3%) and tetradecanol (4.3%) in the oil of T. muralis, nonanal (36.8%) and tricosane (6.5%) in the oil of H. lutescens, nonanal (12.5%) and 2E-tetradecen-1-ol (6.9%) in the oil of H. cupressiforme, and nonanal (7.8%) and 2E-tetradecen-1-ol (7.1%) in the oil of P. nutans. The essential oils of T. muralis, H. lutescens, H. cupressiforme, and P. nutans were rich as in non-terpenoid components …

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Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hacer Bayrak, Hakan Bektaş, Şengül Alpay Karaoğlu Jan 2010

Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hacer Bayrak, Hakan Bektaş, Şengül Alpay Karaoğlu

Turkish Journal of Chemistry

The synthesis of ethyl [3-(cyanomethyl)-5-alkyl-4H-1,2,4-triazol- 4-yl]carbamates (2a-d) was performed starting from ethyl 2-[ethoxy(4- (aryl)methylene]hydrazinecarboxylates (1a, 1b). The treatment of 2a with thiosemicarbazide afforded ethyl [3-[(5-amino-1,3,4-thiadiazol- 2-yl)methyl]-5-(4-nitrophenyl)-4H-1,2,4-triazol-4-yl]carbamates (3a), whereas compound 2b produced 5-{[4-amino-5-(4-methylphenyl)- 4H-1,2,4-triazol-3-yl]methyl}-1,3,4-thiadiazol-2-amine (3b) in the same reaction conditions. The treatment of tert-butyl 2-[2-(4-chlorophenyl)-1-ethoxyethylidene]hydrazinecarboxylate (5) with malonohydrazide or cyanoacethydrazide gave the corresponding 1,2,4-triazol-ylcarbamate derivatives (6 or 9); then the hydrolysis of these compounds resulted in the formation of 3-{[4-amino-5-(4- chlorobenzyl)-4H-1,2,4-triazol-3-yl]methyl}-5-(4-chlorobenzyl)-4H- 1,2,4-triazol-4-amine (7) and [4-amino-5-(4-chlorobenzyl)-4H- 1,2,4-triazole-3-yl]acetonitrile (10), respectively. The synthesis of the Schiff base derivatives 3-(4-chlorobenzyl)-5-{[5-(4-chloroben- zyl)-4-[(2-hydroxyphenyl-methylene)amino]-4H-1,2,4-triazol-3-yl]methyl} -N-(2-hydroxyphenylmethylene)-4H-1,2,4-triazol-4-amine (8), and (5-(4-chlorobenzyl)-4-{[(2,6-dichlorophenyl)methylene]amino}-4H-1,2,4- triazol-3-yl)acetonitrile (12) was performed from the reaction of compounds 7 …

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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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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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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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Nile Blue-Hexacyanoferrate Carbon Paste Modified Electrode As An Amperometric Sensor For Determination Of Hydrazine, Reza Sabzi, Elnaz Minaie, Khalil Farhadi, Mirmaqsoud Golzan Jan 2010

Nile Blue-Hexacyanoferrate Carbon Paste Modified Electrode As An Amperometric Sensor For Determination Of Hydrazine, Reza Sabzi, Elnaz Minaie, Khalil Farhadi, Mirmaqsoud Golzan

Turkish Journal of Chemistry

The main problem associated with metal hexacyanoferrates (MHCFs) is their instability at high pH values. We synthesized a new Prussian Blue analogue, Nile-Blue hexacyanoferrate (NBHCF), that remains stable in 0.2 M KOH. A carbon paste (CPE) chemically modified electrode (ME) containing NBHCF was prepared as a stable electrochemical sensor for measuring hydrazine. A detailed characterization of the electrochemical and electrocatalytic behavior of NBHCF was performed using cyclic voltammetric, chronoamperometric, differential pulse voltammetric (DPV) and hydrodynamic amperometric methods. The NBHCF-modified electrode produced reproducible redox peaks and resulted in a linear increase in the oxidation signal of hydrazine with increasing concentration of …

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Determination Of Trace Element Contents Of Thymus Species From Turkey, Fatümetüzzehra Küçükbay, Ebru Kuyumcu Jan 2010

Determination Of Trace Element Contents Of Thymus Species From Turkey, Fatümetüzzehra Küçükbay, Ebru Kuyumcu

Turkish Journal of Chemistry

Eleven mineral and trace elements (Mg, Ca, K, Fe, Mn, Al, Zn, Cu, Cd, Ni, and Pb) were determined in the Thymus species growing in Turkey. The total concentrations were measured in samples mineralized with concentrated nitric acid and hydrogen peroxide in a microwave system. The determination of mineral and trace elements in the leaves of the Thymus species was carried out by flame and graphite furnace atomic absorption spectrometry. The accuracy of the method was ensured by using standard reference material (NIST-SRM 1515 apple leaves). The concentration of elements in the Thymus species and their biological activity on humans …

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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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On The Potential Of Limitation-Oriented Malware Detection And Prevention Techniques On Mobile Phones, Qiang Yan, Robert H. Deng, Yingjiu Li, Tieyan Li Jan 2010

On The Potential Of Limitation-Oriented Malware Detection And Prevention Techniques On Mobile Phones, Qiang Yan, Robert H. Deng, Yingjiu Li, Tieyan Li

Research Collection School Of Computing and Information Systems

The malware threat for mobile phones is expected to increase with the functionality enhancement of mobile phones. This threat is exacerbated with the surge in population of smart phones instilled with stable Internet access which provides attractive targets for malware developers. Prior research on malware protection has focused on avoiding the negative impact of the functionality limitations of mobile phones to keep the performance cost within the limitations of mobile phones. Being different, this paper investigates the positive impact of these limitations on suppressing the development of mobile malware. We study the state-of-the-art mobile malware, as well as the progress …

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Email Data Mining: An Approach To Construct An Organization Position-Wise Structure While Performing Email Analysis, Bhargav Vadher Jan 2010

Email Data Mining: An Approach To Construct An Organization Position-Wise Structure While Performing Email Analysis, Bhargav Vadher

Master's Projects

In this age of social networking, it is necessary to define the relationships among the members of a social network. Various techniques are already available to define user- to-user relationships across the network. Over time, many algorithms and machine learning techniques were applied to find relationships over social networks, yet very few techniques and information are available to define a relation directly over raw email data. Few educational societies have developed a way to mine the email log files and have found the inter-relation between the users by means of clusters. Again, there is no solid technique available that can …

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Geometrical Structure And Analysis Of Association Rule, Rajat Sar Jan 2010

Geometrical Structure And Analysis Of Association Rule, Rajat Sar

Master's Projects

Association rule mining helps us to identify the association between items from a large transactional data set. It has always been a time consuming process because of repeatedly scanning of the data set. Apriori Algorithm [1] and FP-Tree Algorithm [2] are the two methods to find out the association of items in a large transactional item set. Both the above algorithm works differently (Apriori follows Bottom-Up Approach & FP-Tree follows Top-Down Approach) in order to get the association. Associations of items generated from the above two algorithms can be represented in geometry. The geometrical form of associations is called Simplical …

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A Technique To Accelerate Stochastic Markov Chain Monte Carlo Simulations Of Calcium-Induced Calcium Release In Cardiac Myocytes, George Williams, Mohsin Saleet Jafri, Aristide Chikando, Gregory Smith Jan 2010

A Technique To Accelerate Stochastic Markov Chain Monte Carlo Simulations Of Calcium-Induced Calcium Release In Cardiac Myocytes, George Williams, Mohsin Saleet Jafri, Aristide Chikando, Gregory Smith

Arts & Sciences Articles

No abstract provided.

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Automated Reduction Of Calcium Release Site Models Via State Aggregation, Yan Hao, Peter Kemper, Gregory D. Smith Jan 2010

Automated Reduction Of Calcium Release Site Models Via State Aggregation, Yan Hao, Peter Kemper, Gregory D. Smith

Arts & Sciences Articles

No abstract provided.

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Brightest Cluster Galaxies And Core Gas Density In Rexcess Clusters, Deborah B. Haarsma, Luke Leisman, Megan Donahue, Seth Bruch Jan 2010

Brightest Cluster Galaxies And Core Gas Density In Rexcess Clusters, Deborah B. Haarsma, Luke Leisman, Megan Donahue, Seth Bruch

University Faculty Publications and Creative Works

We investigate the relationship between brightest cluster galaxies (BCGs) and their host clusters using a sample of nearby galaxy clusters from the Representative XMM-Newton Cluster Structure Survey. The sample was imaged with the Southern Observatory for Astrophysical Research in R band to investigate the mass of the old stellar population. Using a metric radius of 12 h -1kpc, we found that the BCG luminosity depends weakly on overall cluster mass as L BCG M 0.180.07cl, consistent with previous work. We found that 90% of the BCGs are located within 0.035 r 500 of the peak of the X-ray emission, including …

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Hard Photodisintegration Of A Proton Pair, I. Pomerantz, N. Bubis, K. Allada, A. Beck, B. L. Berman, W. Boeglin, A. Camsonne, M. Canan, K. Chirapatpimol, E. Cisbani Jan 2010

Hard Photodisintegration Of A Proton Pair, I. Pomerantz, N. Bubis, K. Allada, A. Beck, B. L. Berman, W. Boeglin, A. Camsonne, M. Canan, K. Chirapatpimol, E. Cisbani

Physics Faculty Publications

We present a study of high energy photodisintegration of proton-pairs through the γ + 3He → p + p + n channel. Photon energies, Eγ , from 0.8 to 4.7 GeV were used in kinematics corresponding to a proton pair with high relative momentum and a neutron nearly at rest. The s−11 scaling of the cross section, as predicted by the constituent counting rule for two nucleon photodisintegration, was observed for the first time. The onset of the scaling is at a higher energy and the cross section is significantly lower than for deuteron (pn pair) photodisintegration. …

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1, 2-Bis (Phenylsulfonyl)-1h-Indole As An Acceptor Of Organocuprate Nucleophiles, David C. Qian, Philip E. Alford, Tara L. S. Kishbaugh, Sean T. Jones, Gordon W. Gribble Jan 2010

1, 2-Bis (Phenylsulfonyl)-1h-Indole As An Acceptor Of Organocuprate Nucleophiles, David C. Qian, Philip E. Alford, Tara L. S. Kishbaugh, Sean T. Jones, Gordon W. Gribble

Dartmouth Scholarship

1,2-Bis(phenylsulfonyl)-1H-indole is a novel example of an electron-deficient indole that undergoes nucleophilic attack at C-3. Though a variety of other organometallic nucleophiles fail to engender nucleophilic substitution, organocuprates produce 3-substituted 2-(phenylsulfonyl)-1H-indoles. These reactions contribute to the growing number of examples of nucleophilic addition to the indole core.

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