Yazar "Kazanci, N" seçeneğine göre listele

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    Comparative pecularities of non-uniform textures of lyotropic mesophases of binary and ternary systems based on N-cetyl-N,N,N-trimethyl ammonium bromide
    (Elsevier Science Bv, 2003) Nesrullajev, A; Okcan, M; Kazanci, N
    The mesomorphic properties of the n-cetyl-n,n,n-trimethyl-ammonium bromide (CTABr) + water and CTABr + decanol + water lyotropic systems and the morphologic properties of the lyotropic mesophases taking place in these systems have been investigated. The existence of hexagonal and nematic-calamitic mesophases in the CTABr + water system and the existence of hexagonal, lamellar, nematic-calamitic and nematic-discotic mesophases in the CTABr + decanol + water system have been revealed. The characters and peculiarities of specific textures, which were spontaneously formed, and non-specific textures, which were induced by deformations, have been investigated. The disclinations of strength and optical signs of singularities taking place in specific and non-specific textures of these lyotropic mesophases have been determined. (C) 2003 Elsevier B.V. All rights reserved.
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    Comparative pecularities of non-uniform textures of lyotropic mesophases of binary and ternary systems based on N-cetyl-N,N,N-trimethyl ammonium bromide
    (Elsevier Science Bv, 2003) Nesrullajev, A; Okcan, M; Kazanci, N
    The mesomorphic properties of the n-cetyl-n,n,n-trimethyl-ammonium bromide (CTABr) + water and CTABr + decanol + water lyotropic systems and the morphologic properties of the lyotropic mesophases taking place in these systems have been investigated. The existence of hexagonal and nematic-calamitic mesophases in the CTABr + water system and the existence of hexagonal, lamellar, nematic-calamitic and nematic-discotic mesophases in the CTABr + decanol + water system have been revealed. The characters and peculiarities of specific textures, which were spontaneously formed, and non-specific textures, which were induced by deformations, have been investigated. The disclinations of strength and optical signs of singularities taking place in specific and non-specific textures of these lyotropic mesophases have been determined. (C) 2003 Elsevier B.V. All rights reserved.
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    Effect of surfaces: shift of the lyotropic nematic-isotropic liquid phase transition temperatures in nematic-calamitic and nematic-discotic mesophases
    (Elsevier Science Sa, 2002) Nesrullajev, A; Tepehan, F; Kazanci, N
    In the present work, the effect of different surfaces on the lyotropic nematic-isotropic liquid phase transition temperatures in nematic-calamitic and nematic-discotic mesophases and also on the character and temperature width of the heterophase region for these phase transitions has been investigated. The shift of the lyotropic nematic-isotropic liquid phase transition temperatures to the lower values and a change in width of the temperature range of the heterophase regions under the influence of surfaces have been found. (C) 2002 Elsevier Science B.V All rights reserved.
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    Effect of the inorganic salt on the electrical conductivity characteristics of lyotropic nematics
    (Czechoslovak Jnl Of Physics, 1998) Nesrullajev, A; Kazanci, N
    The effect of inorganic salt on temperature dependent changes of the electrical conductivity of N-d and N-c lyotropic nematic mesophases consisting of disc like and rod like micelles has been investigated. It has been found from the temperature dependence of the electrical conductivity that the lyotropic and thermotropic phase transitions shifted to lower temperatures by addition of NH4Br. Addition of the salt stimulates the formation of oriented textures of N-d and N-c mesophases.
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    Effect of YBa2Cu3O7-x thin films on the textures and orientational properties of liquid crystals
    (Springer-Verlag, 2000) Nesrullajev, A; Tepe, M; Abukay, D; Kazanci, N; Demirhan, D; Buyukkilic, F
    In the present work, the effect of thin films of YBa2Cu3O7-x complex compound on the mesomorphic and orientational properties of thermotropic nematic liquid crystals has been studied. Homogeneous, stable and reproducible homeotropic and lilted oriented textures of nematic liquid crystals were obtained. The effect of YBa2Cu3O7-x thin films on the morphologic, orientational and optical properties of thermotropic nematic liquid crystals are discussed.
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    Hexagonal lyotropic liquid crystalline mesophase: change of rod-like micelle sizes with changes in concentrations
    (Elsevier Science Sa, 2003) Nesrullajev, A; Kazanci, N; Yildiz, T
    In the present work, change of rod-like micelle sizes with change of amphiphile concentration in hexagonal mesophase and the effect of inorganic salt additions on the effective length of these micelles have been studied. The investigations were made by the using of electrical conductivity method in shear flow. The dependence of form factor on the anisometricity parameter of rod-like micelles were determined for investigated lyotropic systems. (C) 2003 Elsevier Science B.V. All rights reserved.
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    Hexagonal lyotropic liquid crystalline mesophase: change of rod-like micelle sizes with changes in concentrations
    (Elsevier Science Sa, 2003) Nesrullajev, A; Kazanci, N; Yildiz, T
    In the present work, change of rod-like micelle sizes with change of amphiphile concentration in hexagonal mesophase and the effect of inorganic salt additions on the effective length of these micelles have been studied. The investigations were made by the using of electrical conductivity method in shear flow. The dependence of form factor on the anisometricity parameter of rod-like micelles were determined for investigated lyotropic systems. (C) 2003 Elsevier Science B.V. All rights reserved.
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    Interaction of melatonin with zwitterionic model membranes
    (Biophysical Society, 2004) Severcan, F; Sahin, I; Kazanci, N
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    Ir and Turbidity Studies of Vitamin-E-Cholesterol-Phospholipid Membrane Interactions
    (Portland Press Ltd, 1995) Severcan, F; Kazanci, N; Baykal, U; Suzer, S
    Binary and tertiary mixture of alpha-tocophenol, cholesterol and dimyristoylphospharidylcholine in the form of multilamellar liposomes were investigated by Fourier Transform infrared and visible spectroscopy. Results of the FTIR and turbidity experiments indicate that alpha T decreases or diminishes the effect of cholesterol on the frequency and the bandwidth of the C-H stretching, CH2 scissoring and C=O stretching bands in FTIR spectra and the turbidity measurements (recorded as absorbance values at 440 nm) in phospholipid model membranes.
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    Lyotropic mesomorphism and morphology in non-aqueous solutions of three tetranuclear platinum mesogens with different halogen-bridged groups
    (Elsevier Science Sa, 2002) Nesrullajev, A; Bilgin-Eran, B; Kazanci, N
    The lyotropic mesomorphism and morphological properties of anew type of lyotropic liquid crystalline system, i.e. a tetranuclear platinum mesogen/apolar organic solvent, have been investigated. The texture transformations in a large temperature interval, especially in the phase transition regions have been studied. The temperature widths of the heterophase regions of the nematic-nematic and nematic-isotropic liquid phase transitions have been determined with a high accuracy. (C) 2002 Published by Elsevier Science B.V.
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    Lyotropic nematic mesophases: investigations of mesomorphic and thermo-optical properties
    (Elsevier Science Sa, 2000) Nesrullajev, A; Kazanci, N
    Investigations of mesomorphic and thermo-optical properties of lyotropic nematic-calamitic (N-c) and nematic-discotic (N-d) mesophases are described. The peculiarities of microscopic textures and the temperature and concentration changes of the refractive index and birefringence have been studied. The nematic-isotropic liquid phase transition temperatures and the temperature widths of heterophase regions of the phase transitions from the N-c and N-d mesophases to the isotropic phase have been determined with a high accuracy. Thermic hysteresis in the width of heterophase regions of the phase transitions between nematic mesophases and isotropic liquid have been found. (C) 2000 Elsevier Science S.A. All rights reserved.
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    Melatonin strongly interacts with zwitterionic model membranes - evidence from Fourier transform infrared spectroscopy and differential scanning calorimetry
    (Elsevier Science Bv, 2005) Severcan, F; Sahin, I; Kazanci, N
    Interactions of melatonin with zwitterionic dipalmitoyl phosphatidylcholine (DPPC) multilamellar liposomes (MLVs) were investigated as a function of temperature and melatonin concentration (1-30 mol%) by using two noninvasive techniques, namely Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The investigation of the C-H, C=O, and PO2- antisymmetric double stretching modes in FTIR spectra and DSC studies reveal that melatonin changes the physical properties of the DPPC bilayers by decreasing the main phase transition temperature, abolishing the pretransition, ordering the system in the gel phase, and increasing the dynamics of the system both in the gel and liquid crystalline phases. It also causes significant decrease in the wavenumber for the C=O stretching and PO2- antisymmetric double bond stretching bands, which indicates strong hydrogen bonding The results imply that melatonin locates in the interfacial region of the membrane. Furthermore, in the DSC curve, more than one signal is observed at high melatonin concentrations (24 and 30 mol%), which indicates melatonin-induced phase separation in DPPC membranes. (C) 2005 Elsevier B.V. All rights reserved.
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    Morphology, surface-induced orientational properties and phase transition peculiarities of lyotropic nematic mesophases in pentadecane solutions of tetranuclear platinum mesogens
    (Pergamon-Elsevier Science Ltd, 2002) Nesrullajev, A; Bilgin-Eran, B; Singer, D; Kazanci, N; Praefcke, K
    We have investigated the surface-induced orientational properties and peculiarities of the phase transitions of a lyotropic system, composed of a,sheet-shaped tetranuclear platinum organyl in pentadecane, and exhibiting two different lyotropic nematic mesophases (N-1 and N-2) Corrugated YBa2Cu3O7-x surfaces with a sinusoidal profile have been used to induce planar orientation of these two nematic lyomesophases, which differ significantly with their orientational behavior. We have also measured the birefringence of these nematic mesophases. Based on high-accuracy determinations of the transition temperatures, we are discussing some peculiarities of the phase transitions between the two nematic mesophases and between N-2 mesophase and isotropic liquid, in particular, the width of the heterophase regions between them. (C) 2002 Elsevier Science Ltd. All rights reserved.
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    Peculiarities of the Schlierein textures in lyotropic nematic mesophases
    (Polish Acad Sciences Inst Physics, 1999) Nesrullajev, A; Kazanci, N
    In the present paper the peculiarities of schlieren textures of lyotropic nematic mesophases have been investigated by polythermic polarization microscopy and capillary temperature wedge methods. The lyotropic nematic-calamitics (N-c) and lyotropic nematic-discotics (N-d) formed in binary and ternary systems on the base of tetradecyldimethyl amino bromide and tetradecyldimethyl amino oxide have been the subjects of our investigations. The dynamics of time and temperature transformations of schlieren textures have been studied. The comparative estimation of schlieren textures of N-c and N-d mesophases has been performed. The optical force and optical sign of the schlieren textures observed have been determined.
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    Phase states in potassium oleate plus water and potassium oleate plus water plus decanol lyotropic systems
    (Polish Acad Sciences Inst Physics, 1998) Nesrullajev, A; Kazanci, N; Yildiz, T
    In this work the investigations of the characteristic textures and the dynamics of their concentration and temperature transformations in potassium oleate + water lyotropic system have been carried out. The effect of the decanol on lyotropic mesomorphism as well as on the character of typical textures and the concentration ranges of lyotropic liquid! crystalline mesophases have also been studied. The phase states diagrams of the potassium oleate + water and potassium oleate + decanol + water lyotropic liquid crystalline systems are presented.
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    Refracting and birefringent properties of lyotropic nematic mesophases
    (Pergamon-Elsevier Science Ltd, 2003) Kazanci, N; Nesrullajev, A
    In this work, we investigated refracting, birefringent and thermotropic properties of lyotropic nematic mesophases. In particular, the morphological properties of nematic-calamitic and nematic-discotic lyotropic mesophases have been investigated in the heterophase regions at lyotropic nematic-isotropic liquid phase transitions. The changes in isotropic, mean refractive index, and anisotropic, birefringence, optical properties of the nematic mesophases by the changes in temperature have been observed to have fluctuational character in the heterophase regions of lyotropic nematic-isotropic liquid phase transitions. This character reflects the character of changes in shapes and sizes of micelles and in symmetries of the mesophases in the heterophase region. (C) 2003 Elsevier Science Ltd. All rights reserved.
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    Refracting and birefringent properties of lyotropic nematic mesophases
    (Pergamon-Elsevier Science Ltd, 2003) Kazanci, N; Nesrullajev, A
    In this work, we investigated refracting, birefringent and thermotropic properties of lyotropic nematic mesophases. In particular, the morphological properties of nematic-calamitic and nematic-discotic lyotropic mesophases have been investigated in the heterophase regions at lyotropic nematic-isotropic liquid phase transitions. The changes in isotropic, mean refractive index, and anisotropic, birefringence, optical properties of the nematic mesophases by the changes in temperature have been observed to have fluctuational character in the heterophase regions of lyotropic nematic-isotropic liquid phase transitions. This character reflects the character of changes in shapes and sizes of micelles and in symmetries of the mesophases in the heterophase region. (C) 2003 Elsevier Science Ltd. All rights reserved.
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    Some peculiarities of nematic-isotropic liquid phase transitions in monomorphic and polymorphic mesogens
    (Pergamon-Elsevier Science Ltd, 2002) Nesrullajev, A; Yurtseven, H; Salihoglu, S; Kazanci, N
    In this study, the dynamics of the changes of the morphological properties in the nematic mesophase and in the heterophase regions of the phase transitions between the nematic mesophase and the isotropic liquid for the thermotropic mesogens have been investigated. Experimentally, we have obtained the thermal hysteresis for the investigated phase transitions. For the analysis of the phase transition temperatures and the peculiarities of the heterophase regions, the mean field theory has been used. (C) 2002 Elsevier Science Ltd. All rights reserved.
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    Surface-induced and oriented, textures of smectic liquid crystals: effect of thin films
    (Iop Publishing Ltd, 2002) Nesrullajev, A; Tepe, M; Kazanci, N
    In this work, the effect of YBa2Cu3O7-x complex compound thin films on the morphological, thermotropical, optical and orientational properties of smectic liquid crystals have been studied. The peculiarities of surface-induced textures and dynamics of their temperature transformations have been investigated. Stable, homogeneous and reproducible oriented textures of smectic liquid crystals have been obtained.