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Articles 10141 - 10170 of 10317
Full-Text Articles in Physical Sciences and Mathematics
Kinetics Of Autoxidative Polymerization Of Sunflowerseed Oil, Hüseyin Topallar, Yüksel Bayrak, Mehmet İşcan
Kinetics Of Autoxidative Polymerization Of Sunflowerseed Oil, Hüseyin Topallar, Yüksel Bayrak, Mehmet İşcan
Turkish Journal of Chemistry
The rates of polymerization of unhydrogenated and hydrogenated sunflowerseed oils were measured under atmospheric conditions in the various containers (glass, PET and metal). Polymerization rates showed a strong dependence on the degree of unsaturation and the light transmittance of the containers. The average molecular weights of polymerized oils were determined by viscosity measurements.The relationship between viscosity and average molecular weight was determined. It is seen that unhydrogenated sunflowerseed oil has a higher polymerization rate than hydrogenated oil samples in a glass container and they has higher viscosity values.
Examination Of Historical Textiles With Dyestuff Analyses By Tlc And Derivative Spectrophotometry, Recep Karadağ, Emre Dölen
Examination Of Historical Textiles With Dyestuff Analyses By Tlc And Derivative Spectrophotometry, Recep Karadağ, Emre Dölen
Turkish Journal of Chemistry
A group of historical textiles in the Topkapi Museum, i.e., silk brocades classified as 16th century pieces by art historians, were investigated by TLC and spectrophometric analyses of their dyestuffs for the purpose of dating these pieces. The dyestuffs contained intextile fibers were extracted with acid solutions of varying strength, and the acid extracts were analyzed by both TLC and spectrophotometry, either directly or after an organic solvent extraction step. The first derivative spectra proved to provide more information than the main spectra. In order to eliminate possible interferences in spectrophotometry arising from impurities in the fibers, e.g., compounds containing …
Electron Spin Resonance Studies On Cobalt Carbonic Anhydrase-Substrate Complexes, Çigdem Nuhoğlu, Nazan Demi̇r, Barbaros Nalbantoğlu, Ö. İrfan Küfrevi̇oğlu, Y. Kemal Yoğurtçu, Hasan Özdemi̇r, Enise Ayyildiz
Electron Spin Resonance Studies On Cobalt Carbonic Anhydrase-Substrate Complexes, Çigdem Nuhoğlu, Nazan Demi̇r, Barbaros Nalbantoğlu, Ö. İrfan Küfrevi̇oğlu, Y. Kemal Yoğurtçu, Hasan Özdemi̇r, Enise Ayyildiz
Turkish Journal of Chemistry
The native zinc atom of bovine erythrocyte carbonic anhydrase purified by affinity choromatography was removed by dialysis against pyridine 2,6-dicarboxylic acid. Cobalt carbonic anhydrase was prepared from the zinc-free apoenzyme. The binding conditions of CO_2 and p-nitrophenylacetate to cobalt carbonic anhydrase were investigated by electron spin resonance at different pH levels.
A Novel Glycosidicly Linked Piperidine Alkaloid From Cyclamen Coum, Nurettin Yayli, Cemalettin Baltaci
A Novel Glycosidicly Linked Piperidine Alkaloid From Cyclamen Coum, Nurettin Yayli, Cemalettin Baltaci
Turkish Journal of Chemistry
The structure of a novel piperidine type alkaloid from {\it Cyclamen coum} was established as 2-\beta-D-glycopyranosyl-2-undecil-3,5-dihydroxy-6-carboxypiperidine, {\bf 1,} whose structure has been deduced from spectral data.
A Quantum-Chemical Investigation On 3-(4h-1,2,4-Triazol-4-Yl)-1h-1,2,4-Triazole, Rıza Abbasoğlu, Necdet Saltek, A. Aykut İki̇zler
A Quantum-Chemical Investigation On 3-(4h-1,2,4-Triazol-4-Yl)-1h-1,2,4-Triazole, Rıza Abbasoğlu, Necdet Saltek, A. Aykut İki̇zler
Turkish Journal of Chemistry
The molecular conformations and electronic properties of the 3-(4H-1,2,4-triazol-4-yl)-1H-1,2,4-triazole molecule containing various reaction centers were investigated by the semiempirical methods MNDO, AM1 and PM3. The most stable conformation of the molecule was determined to be the planar conformation. The total energies, heats of formation, dipole moments, rotational barriers, geometric parameters, ionization potentials, full atomic charges, energies of frontier molecular orbitals (E_{HOMO} and E_{LUMO}) and their electron densities were calculated and discussed. In order to determine the protonation sites of the 3,4'-bitriazole system, the molecular electrostatic potential (MESP) of the molecule has also been calculated. The conformations and electronic properties of …
Influence Of Some Crosslinkers On The Swelling Of Acrylamide-Crotonic Acid Hydrogels, Erdener Karadağ, Dursun Saraydin, Olgun Güven
Influence Of Some Crosslinkers On The Swelling Of Acrylamide-Crotonic Acid Hydrogels, Erdener Karadağ, Dursun Saraydin, Olgun Güven
Turkish Journal of Chemistry
Acrylamide-crotonic acid hydrogels in the form of rods are prepared by \gamma-irradiation of quaternary mixtures of acrylamide-crotonic acid-crosslinker-water with 2.6 and 5.2 kGy \gamma-rays. The influence of the applied dose, the relative content of crotonic acid and crosslinkers such as ethylene glycol dimethacrylate, 1.4 butanediol dimethacrylate and N,N' methylenebisacrylamide on the swelling properties of the gel, the diffusional behaviour of water, the diffusion coefficient, and the network parameters of hydrogel systems are examined. Acrylamide-crotonic acid hydrogels containing various crosslinkers had a maximum swelling in the range 240-850 \%. Water diffusion to hydrogels was non-Fickian. The diffusion coefficients varied between 4.6 …
Apocarbonic Anhydrase-Enzymatic Determination Of Zinc In Fruit Juices, Ayşe Karagölge, Nazan Demi̇r, Yaşar Demi̇r, İrfan Küfrevi̇oğlu
Apocarbonic Anhydrase-Enzymatic Determination Of Zinc In Fruit Juices, Ayşe Karagölge, Nazan Demi̇r, Yaşar Demi̇r, İrfan Küfrevi̇oğlu
Turkish Journal of Chemistry
In this study, a new enzymatic method for determining trace amount of zinc was employed on ten different fruit juices. The basis of the enzymatic method is that apocarbonic anhydrase regains its activity in proportion to the Zn^{2+} existing in a solution. Thus, the more activated the enzyme is in the medium, the higher the Zn^{2+} concentration in the solution will be. For this purpose, bovine carbonic anhydrase was purified from erythrocyte hemolisate by affinity chromatography. The Zn^{2+} bound to the enzyme was removed by of the purified enzyme against the solution of pyridine-2-6-dicarboxylic acid. Thus 100\% purified enzyme was …
Investigation Of Hmo Spectra Of Hückel And Mobius Type Cyclacenes, Lemi Türker, Şakir Erkoç
Investigation Of Hmo Spectra Of Hückel And Mobius Type Cyclacenes, Lemi Türker, Şakir Erkoç
Turkish Journal of Chemistry
The Hückel molecular orbital spectra (HMO) of Hückel- and Mobius-type cyclacenes having 3-15 benzenoid rings were investigated and it was found that certain eigenvalues are topologically invariant, whereas others exhibit topological periodicity. For example, Hückel-type cyclacenes having 2r (r: 2,3,4,...) benzenoid rings which possess nonbonding molecular orbitals (NBMO) and are thus expected to be open shell structures.
Investigation Of H-Bond On Fluorescence Changes In Benzene Derivations And Different Acceptor Systems, Nursel Acar Bayri, Özgül Koçak
Investigation Of H-Bond On Fluorescence Changes In Benzene Derivations And Different Acceptor Systems, Nursel Acar Bayri, Özgül Koçak
Turkish Journal of Chemistry
In this study, benzene derivatives of phenol and naphtol were selected as donor systems and mixed with dioxane and TEA (triethylamine), which were chosen as acceptors. H-bond formation in the phenol-triethylamine binary system was investigated by both UV absorption and emission spectroscopies. The changes in the absorption and emission spectra by H-bond formation and the equilibrium of the H-bonded complexes were studied at both the ground and excited states. In addition, equilibrium constants at different temperatures and thermodynamic properties related to equilibrium (enthalpy, fere energy change and entropy values of H-bond formation) were calculated. A shift to longer wavelengths and …
Thermodynamics Of Dissociation Of Strontium, Barium And Nickel Caproates In Water, Hüseyin Topallar, Yüksel Bayrak, Mehmet İşcan
Thermodynamics Of Dissociation Of Strontium, Barium And Nickel Caproates In Water, Hüseyin Topallar, Yüksel Bayrak, Mehmet İşcan
Turkish Journal of Chemistry
The critical micellar concentration (CMC) and thermodynamic parameters (heat \DeltaH_d, free energy \DeltaG_d, and entropy \DeltaS_d, of dissociation) of aqueous solutions of strontium, barium and nickel caproates were determined by conductivity measurements. A Kraus and Bray-type expression was used to evaluate molecular conductance at infinite dilution and theromdynamic parameters. The results confirm that CMC remains unaffected by temperature in the range of 25-55^{\circ}C, and show that the dissociation of soaps is an exothermic reaction and nonspontaneous.
Some Oxidation Reactions Of Isomeric Pyridinecarboxylic Acid Hydrazides, Rashid Iqbal, Samia Ebrahim, Muhammad Ziaulhaq
Some Oxidation Reactions Of Isomeric Pyridinecarboxylic Acid Hydrazides, Rashid Iqbal, Samia Ebrahim, Muhammad Ziaulhaq
Turkish Journal of Chemistry
The oxidation reactions of the three isomeric pyridinecarboxylic acid hydrazides were studied using sodium metaperidoate, silver(I) oxide and potassium ferricyanide separately. Potassium ferricyanide emerged as an excellent reagent for preparation of 2-pyridinecarboxaldehyde and 3-pyridinecarboxaldehyde from the respective isomeric pyridinecarboxylic acid hydrazides. Oxidation with silver(I) oxide in each case yielded the corresponding 1,2-dipyridoylhydrazine, while sodium metaperiodate furnished different products with each isomeric pyridinecarboxylic acid hyrazide.
Effect Of Various Additives On The Hydration Of Perlite-Gypsum Plaster And Perlite-Portland Cement Pastes, Emin Erdem
Effect Of Various Additives On The Hydration Of Perlite-Gypsum Plaster And Perlite-Portland Cement Pastes, Emin Erdem
Turkish Journal of Chemistry
Perlite is a volcanic glass which forms a light-weight cellular aggregate when ground and heated to about 1000\ci. It is used in the production of light-weight masonry blocks and concrete in the building industry as well as in insulation, fire protection, agriculture and pharmacology. In this study, the effects of admixtures such as lime, sodium citrate and various superplasticizers on the hydration of perlite-gypsum plaster, perlite-white Portland cement and perlite-blended Portland cement mixtures were investigated by measurement of flexural and compressive strengths and by DTA-TG. It was found that the addition of lime caused pozzolanic reactions and, consequently, increased strength …
The Synthesis Of Some Novel Chromans, M. Yalçinkaya, O. Bi̇lgi̇ç, S. Bi̇lgi̇ç
The Synthesis Of Some Novel Chromans, M. Yalçinkaya, O. Bi̇lgi̇ç, S. Bi̇lgi̇ç
Turkish Journal of Chemistry
The inverse-electron demanded Diels-Alder reaction of 1-N,N-dimethylaminomethyl-2-naphthol (1) with substituted styrenes were investigated. With 2-, 3-, 4-methylstyrenes, 2-(2'-,3'- and 4'-methylphenyl)-benzo-5,6-chromans (5, 6 and 7) were obtained in 12, 18 and 53 \% yields respectively. With 2-, 3- and 4-chlorostyrenes, 2-(2'-, 3'- and 4'-chlorophenyl)-benzo-5,6-chromans (8,9 and 10) were obtained in 8, 20 and 33 \% yields respectively. With 4-vinyl-pyridine, 2-($4'-pyridyl)-benzo-5,6-chroman (11) was obtained in 48\% yield. In all pyrolysis no quinone-methide dimer (4) was encountered.
Catalytically Active Intermediates In Photochemical Metathesis, Çetin Bozkurt, Yavuz İmamoğlu
Catalytically Active Intermediates In Photochemical Metathesis, Çetin Bozkurt, Yavuz İmamoğlu
Turkish Journal of Chemistry
The nature of the active species in photocatalytic metathesis reaction was investigated. The formation of Wittig-type addition products with benzaldehyde indicates that catalytically active carbene is the product of olefin and tungsten hexacarbonyl under reaction conditions.
Synthesis Characterization And Miscibility Of Polyvinyl Butyrals Of Varying Vinyl Alcohol Contents, Z. M. Zhou, D. J. David, W. J. Macknight, F. E. Karasz
Synthesis Characterization And Miscibility Of Polyvinyl Butyrals Of Varying Vinyl Alcohol Contents, Z. M. Zhou, D. J. David, W. J. Macknight, F. E. Karasz
Turkish Journal of Chemistry
Polyvinyl butyrals (PVB) of systematically varying vinyl alcohol content have been synthesized and characterized using wet chemistry, IR, DSC, and TGA. The miscibility of PVB-PVB blends was studied by DSC as a function of vinyl alcohol content and vinyl alcohol content differences between the respective blend components. These data were use to construct an isothermal miscibility map of PVB and to calculate the intramolecular interaction parameter \chi_{VA,VB}. The \chi_{VA,VB} was a function of the absolute level of the vinyl alcohol (VA) and vinyl butyral (VB) contents of the polymers. In addition, the thermal stability of polyvinyl butyral was found to …
Dielectric Studies Of Various Olefin/So2 Copolmers, B. Baysal, Candan Erbi̇l, Paul L. Morganelli, W. H. Stockmayer
Dielectric Studies Of Various Olefin/So2 Copolmers, B. Baysal, Candan Erbi̇l, Paul L. Morganelli, W. H. Stockmayer
Turkish Journal of Chemistry
Dielectric constant and loss have been measured at low and high frequencies for several poly(1-olefin sulfones) as well as for the polysulfones of allybenzene and allyl cyclopentane. The low-frequency dispersion in allylbenzene due to helical sequences is weaker in benzene than in dioxane, and in both solvents is much lower than for the 1-olefin polymers. Solvent effects on the high frequency process are also reported, but yield no simple uniform picture.
Network Characterization Of Energetic Poly(Glycidyl-Azide), Mehmet S. Eroğlu, Olgun Güven
Network Characterization Of Energetic Poly(Glycidyl-Azide), Mehmet S. Eroğlu, Olgun Güven
Turkish Journal of Chemistry
Energetic poly(glycidyl azide) (PGA) elastomers with different crosslink densities were prepared by varying the NCO/OH reactive-groups ratio from 0.8 to 1.0. In the preparation of the elastomers, PGA chains were end-liked with a mixture of hexamethylene diisocyanate (HMDI) and trimethylol propane (TMP) at a fixed TMP/PGA mole ratio. The number average molar mass between junction points of the network chains \overline{{\rm M}}_c was calculated using data obtained from swelling and uniaxial tensile tests and the results were compared. For the mechanical characterization of the networks, Mooney-Rivlin plots were prepared and the values of the constants 2C_1 and 2C_2 of PGA …
Features Of Graft Copolymer Formation Through Reaction Of Functionalized Polyolefins With Poly-\Epsilon-Caprolactam, Elisa Passaglia, Francesco Picchioni, Mauro Aglietto, Giocomo Ruggeri, Francesco Ciardelli
Features Of Graft Copolymer Formation Through Reaction Of Functionalized Polyolefins With Poly-\Epsilon-Caprolactam, Elisa Passaglia, Francesco Picchioni, Mauro Aglietto, Giocomo Ruggeri, Francesco Ciardelli
Turkish Journal of Chemistry
The reaction in the melt of polyolefins containing 2-diethylsuccinate groups (DES) with poly-\epsilon-caprolactam (PA6) to give a graft copolymer was investigated under different conditions. Even using a large excess of DES groups over the PA6 terminal amino groups the graft copolymer yield resulted only partial thus suggesting a kinetic control of the reaction. The effect of various catalysts was then examined taking into account results obtained in a model reaction between a low molecular weight amine and diethylsuccinate. The results are discussed in terms of side reactions and miscibility of the pristine polymers.
Synthesis Of The New Cation Exchange Resins Having Poly (Styrene-Caprolactone) Units, S. Savaşkan Yilmaz, Hulisi Özbayrak, Baki Hazer
Synthesis Of The New Cation Exchange Resins Having Poly (Styrene-Caprolactone) Units, S. Savaşkan Yilmaz, Hulisi Özbayrak, Baki Hazer
Turkish Journal of Chemistry
The crosslinked polystyrene-polycaprolactone , PS-PCL-, block copolymers were prepared by the copolymerization of styrene and poly(caprolacton dimethylmethacrylate) (PCL-DM). The molecular weights of polycaprolactone, PCL, PCL-DM were 1250 and 2000. The swelling in H_2O or CHCl_3 of the sulfonated and unsulfonated block copolymers were determined under comparable conditions and investigated. The capacities of the obtained ion exchange resins were 1.31 and 1.10 meq/g.
Thermal Stabilities Of Hydroxyalkyl Terminated Polydimethylsiloxane Oligomers, İskender Yi̇lgor, Emel Yi̇lgor
Thermal Stabilities Of Hydroxyalkyl Terminated Polydimethylsiloxane Oligomers, İskender Yi̇lgor, Emel Yi̇lgor
Turkish Journal of Chemistry
The thermal stabilities of \alpha,\omega-hydroxypropyl, \alpha,\omega-hydroxybutyl \alpha,\omega-2-hydroxypentyl and \alpha,\omega-hydroxyhexyl terminated polydimethylsiloxane oligomers were investigated. Hydroxypropyl and hydroxybutyl terminated polydimethylsiloxane oligomers showed degradation upon heating through the loss of functional end groups, as determined by FTIR spectroscopy and gel permeation chromatography. \alpha,\omega-Hydroxyhexyl and \alpha,\omega-2-hydroxypentyl terminated polydimethylsiloxane oligomers were stable under similar conditions. The instability of the end groups is due to the backbiting of the terminal silicon in the PDMS by the primary hydroxyl oxygen, leading to the formation of 5-and 6-membered stable, heterocylic compounds. Loss of end groups also resulted in a dramatic increase in the molecular weights of the …
New Synthetic Approach For The Synthesis Of Liquid Crystalline Block And Graft Copolymers, Yeşim Hepuzer, İ. Ersin Serhatli, Yusuf Yağci
New Synthetic Approach For The Synthesis Of Liquid Crystalline Block And Graft Copolymers, Yeşim Hepuzer, İ. Ersin Serhatli, Yusuf Yağci
Turkish Journal of Chemistry
Liquid crystalline block and graft copolymers were synthesized according to the macroinitiator and macroinimer concept. For this purpose, side chain block copolymers (polytetrahydrofuran-b-polymethylmethacrylate) having liquid crystalline 4,4'- cyanobiphenyl blocks were prepared and characterized. Unlike the liquid-crystalline homopolymer with mesogenic units in the side chain, all block and graft copolymers showed a smectic A mesophase. The transition temperatures are hardly affected by the composition and molecular weight of the blolck copolymers.
Electrical Conductivity Of Sodium Doped Poly(4-Vinylpyridine), Murat Özyalçin, Zuhal Küçükyavuz, Aref Jarvaherian, Savaş Küçükyavuz
Electrical Conductivity Of Sodium Doped Poly(4-Vinylpyridine), Murat Özyalçin, Zuhal Küçükyavuz, Aref Jarvaherian, Savaş Küçükyavuz
Turkish Journal of Chemistry
Poly(4-Vinylpyridine) was synthesized by free radicalic polymerization. Solution doping process with metallic sodium was carried out. A conductivity value around 10^{-6} S/cm was obtained. Relative change in the coductivity with dopant concentration, temperature dependence of conductivity, conductivity behavior in atmospheric conditions for the samples were analyzed. SEM and EDX techniques were also used for the characterization of the polymer.
Conducting Polymer Grafts Of Polypyrrole, Levent Toppare
Conducting Polymer Grafts Of Polypyrrole, Levent Toppare
Turkish Journal of Chemistry
Conducting polymer grafts of pyrrole with poly[(methyl methacrylate)-co-(2-(N-pyrollyl) ethyl methacrylate)] wwere synthesized via elctrochemical polymerization of pyrrole in different media. Samples were characterized by SEM, thermal analysis and conductivity measurements.
Crystal Structure Effect In Radiation-Induced Solid-State Polymerization Of Acrylamide, Ali Usanmaz
Crystal Structure Effect In Radiation-Induced Solid-State Polymerization Of Acrylamide, Ali Usanmaz
Turkish Journal of Chemistry
Crystal structure of arcylamide at -150^{\circ}C was studied to understand the role of the crystal structure on the reaction mechanism of radiation-induced polymerization in the solid-state. Acrylamide crystallizes in the monoclinic unit cell with the unit cell parameters as ; a=828.0(2) pm, b=578.0(4) pm, c=974.9(2) pm, \beta=119.62(4)^0, space group =P 2_1/c, Z=4 molecules/unit cell, d_x = 1.165 g/cm^3. From the results of the structural data a polymerization mechanism in the solid-state is suggested. The radiation damage in single crystal of acrylamide was also investigated in detail. The result showed the formation of the amorphous polymer, that phase separated from the …
Electrical Conductivities Of Poly (Alkyl Vinyl Ketones) Reacted With Dopant Solutions, Jun Hui Ma, J. David Tauber, Ülkü S. Ramelow
Electrical Conductivities Of Poly (Alkyl Vinyl Ketones) Reacted With Dopant Solutions, Jun Hui Ma, J. David Tauber, Ülkü S. Ramelow
Turkish Journal of Chemistry
Poly ethyl vinyl ketone (PEVK) and poly methyl vinyl ketone (PMVK) were prepared using photochemical processes. The irradiation of monomers with UV light provides a new method, different from the methods previously used for the polymerization of these monomers. FTIR and UV spectroscopies were used for the structure and reaction mechanism of the polymers. NMR was used to calculate the conversion percentage of MVK and EVK polymers. The conductivity change at various temperatures was traced during reactions of PMVK and PEVK with various dopant concentrations and the activation energy of these reactions were calculated by adding dopants and by adjusting …
A Two-Dimensional Monte Carlo Polymerization Of 5-Membered Rings, Okan Esentürk, H. Önder Pamuk, E. Yurtsever
A Two-Dimensional Monte Carlo Polymerization Of 5-Membered Rings, Okan Esentürk, H. Önder Pamuk, E. Yurtsever
Turkish Journal of Chemistry
A modification of the kinetic growth model in two dimensions for the polymerization of 5-membered rings is presented. The preliminary results reveal the validity of the modified model.
Phase Transition Of Hydrolyzed Polyacrylamide Gels In Aqueous Solutions Of Poly(Ethylene Glycol), Nilhan Kayaman, Oğuz Okay, B. M. Baysal
Phase Transition Of Hydrolyzed Polyacrylamide Gels In Aqueous Solutions Of Poly(Ethylene Glycol), Nilhan Kayaman, Oğuz Okay, B. M. Baysal
Turkish Journal of Chemistry
Hydrolyzed polyacrylamide gels immersed in aqueous solutions of poly(ethylene glycol) (PEG) of molecular weight 300 exhibit a discontinuous volume change upon continuous increase of the PEG concentration in the external solution. As the duration of hydrolysis increases, that is, as the proportion of the ionic groups on the network chains increases, the critical concentration of PEG required for a discontinuous volume change rises and, also, the magnitude of the volume collapse becomes larger. Experimental results indicate that the gel collapse in PEG solution is due to the osmotic deswelling of the ionic gel rather than due to a complex formation …
High Rates Of Fluorescence Quenching Between Perylene Dodecyldiimide And Certain \Pi-Electron Donors, S. İçli̇, H. İci̇l, İ. Gürol
High Rates Of Fluorescence Quenching Between Perylene Dodecyldiimide And Certain \Pi-Electron Donors, S. İçli̇, H. İci̇l, İ. Gürol
Turkish Journal of Chemistry
Perylene bis-n-dodecyl diimide is found to quench fluorescenc emissions of naphthalene, phenanthrene and dihydrocarbazolocarbazole molecules at rates of 4.4\times10^{11}, 2.8\times10^{12} and 2.5\times10^4 M^{-1} sec^{-1}, in respective order of aromaticity. These unusulally high rates of fluorecence quenchings are attributed to Perrin model static quenching and presence of electron transfer through singlet excited state of perylene diimide. Calculated free energy of electron transfer, \Delta G_{ET}=-120.5 kJ/mol, between perylene diimide and dihydrocarbazolocarbazole is taken as evidence for observation of high fluorescence quenching rate for carbazolocarbazole molecule. Keywords: Fluorescence quenching, Photoenergy transfer, Perylene diimide and Carbazolocarbazole
Possible Roles Of Transition Metals In Cloudwater Relative To The Solar Short-Wave Radiation Absorption Anomaly, Xudong Huang, S. Sinan Keski̇n, Francis Pink, İlhan Ölmez
Possible Roles Of Transition Metals In Cloudwater Relative To The Solar Short-Wave Radiation Absorption Anomaly, Xudong Huang, S. Sinan Keski̇n, Francis Pink, İlhan Ölmez
Turkish Journal of Chemistry
Measurements of the absorption of solar short-wave radiation by clouds exceed those predicted by theoretical calculations. In order to understand the roles of minor and trace species in this absorption anomaly, cloudwater samples were collected from individual precipitating clouds and analyzed for trace metals and anionic species. Two generalized approaches were used to assess the direct impact of the absorption of solar short-wave radiation by transition metals and/or their anionic complexes. Additionally, it was suggested that iron and manganese may act as catalyts in the formation of sulfate aerosols which efficiently scatter solar radiation.
Constituents Of Salvia Verticillata, Ufuk Sönmez, Gülaçtı Topçu, Ayhan Ulubelen
Constituents Of Salvia Verticillata, Ufuk Sönmez, Gülaçtı Topçu, Ayhan Ulubelen
Turkish Journal of Chemistry
Three new and fourteen known compounds were isolated from the roots of {\it Salvia verticillata L.} Spectral methods were used for the structure determination besides TLC comparisons with authentic samples for the known compounds.