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111.
Debanjan Bhattacharjee Parameswara Rao Alapati 《Molecular Crystals and Liquid Crystals》2017,648(1):66-76
This article represents the electrical studies of an interdigitated highly skewed N(4-n-pentyloxybenzylidene) 4-n-alkylaniline (5O.16) compound. Interestingly the compound is partially bent like and unsymmetrical in alkyl chain length. Dielectric and impedance spectroscopy studies indicate the coupling between the liquid crystal and the electrical field. Studies were carried out as a function of temperature as well as frequency. Semicircular nature of the Cole–Cole plots indicates the reorientation of the molecule with the applied field. Using the experimental data and the theoretically fitted results the effective equivalent model circuit was designed. Which used to explain the behavior of the compound under the external electric effect and the influence of the electrodes with different variable represent the resistor circuit. However, the effect of the conductivity of temperature and frequency are also reported. 相似文献
112.
To the best of our knowledge, bioanalytical methods to determine rosiglitazone in human plasma reported in literature use internal standards that are not commercially available. Our purpose was to develop a simple method for the determination of rosiglitazone in plasma employing a commercially available internal standard (IS). After the addition of celecoxib (IS), plasma (0.25 mL) samples were extracted into ethyl acetate. The residue after evaporation of the organic layer was dissolved in 750 microL of mobile phase and 50 microL was injected on to HPLC. The separation was achieved using a Hichrom KR 100, 250 x 4.6 mm C(18) with a mobile phase composition potassium dihydrogen phosphate buffer (0.01 m, pH 6.5):acetonitrile:methanol (40:50:10, v/v/v). The flow-rate of the mobile phase was set at 1 mL/min. The column eluate was monitored by fluorescence detector set at an excitation wavelength of 247 nm and emission wavelength of 367 nm. Linear relationships (r(2) > 0.99) were observed between the peak area ratio rosiglitazone to IS vs rosiglitazone concentrations across the concentration range 5-1000 ng/mL. The intra-run precision (%RSD) and accuracy (%Dev) in the measurement of rosiglitazone were <+/-10.69 and <-12.35%, respectively across the QC levels (50-1000 ng/mL). The extraction efficiency was >80% for both rosiglitazone and IS from human plasma. The lower limit of quantitation of the assay was 5 ng/mL. In summary, the methodology for rosiglitazone measurement in plasma was simple, sensitive and employed a commercially available IS. 相似文献
113.
114.
K. R. K. Rao J. V. Rao P. Venkatacharyulu S. V. Chiranjeevi Rao V. Ballah 《Crystal Research and Technology》1986,21(12):1573-1576
Phase transition studies of the liquid crystal, 4-[4-n-pentyloxybenzylidene–amino]–azobenzene (PBAAB) have been investigated by thermal microscopy and Differential Scanning Calorimetry (DSC) studies. From these studies it is confirmed that the compound, PBAAB exhibits nematic, smectic A and smectic B phases. The textures exhibited by different phases are presented. The enthalpies and entropies at various phase transitions are also reported. 相似文献
115.
Y. C. Venudhar Leela Iyengar K. V. Krishna Rao 《Crystal Research and Technology》1985,20(10):1393-1398
The precision lattice parameters of osmium dioxide have been determined at different temperatures, in the temperature range 30–444 °C, using a Unicam high temperature powder camera 19 cm in diameter and CuKα radiation. The data have been used to evaluate the coefficients of thermal expansion at various temperatures by a graphical method. The ‘a’ parameter increases non-linearly with increasing temperature while the ‘c’ parameter remains constant throughout the range of temperature studied indicating a zero coefficient of expansion along the c-direction. The abnormal thermal behaviour of this compound is explained in terms of the electronic configuration of the d-shell of the cation. 相似文献
116.
117.
N. Pandaraiah K. Narasimha Reddy U. V. Subba Rao B. M. Wanklyan 《Crystal Research and Technology》1984,19(4):571-576
Thermoluminescence (TL) studies of cobalt-doped Al2O3 crystals irradiated with X-rays have shown that the TL glow curve consists of three peaks at 105, 195 and 260°C. Bleaching, annealing and quanching studies have been performed in order to understand the nature of colour centers responsible for the formation of the three peaks. The values of the fundamental parameters like trap depth and frequency factor are estimated from TL data and the results obtained are discussed. 相似文献
118.
Elevated irradiation temperature studies with NaYF4 samples reveal that the intensity of the two glow peaks observed around 120 and 180°C enhances. The effect of temperature of irradiation (Tirr) on the sensitisation of the both peaks are studied. The half lives of these glow peaks were calculated and concluded that the half lives of these peaks decreases with the increase in irradiation temperatures. 相似文献
119.
S.V.N Bhaskara Rao T.K. Balasubramanian 《Journal of Quantitative Spectroscopy & Radiative Transfer》2004,87(2):203-210
Fresh computations of rovibrational matrix elements of the polarizability α[=(α||+2α⊥)/3] and the polarizability anisotropy γ(=α||−α⊥) of the heteronuclear isotopomers, HD, HT, and DT, of the hydrogen molecule are presented. The computations combine the most accurate polarizability functions α(R) and γ(R) (R being the bond distance) on the one hand and the most accurate adiabatic potential on the other. The calculations are extended to the product operators xα and xγ where x is the centre of mass to centre of charge separation in the heteronuclear species. The latter matrix elements are needed, additionally, for elucidating the absorption intensities of some of the zero-phonon rovibrational transitions peculiar to the heteronuclear species in the crystalline phase. 相似文献
120.
Zinc oxide thin films have been deposited on glass substrates at a substrate temperature of 673 K by spray pyrolysis. The
samples are annealed in ambient atmosphere at various temperatures. The effect of annealing on structural, electrical, and
optical properties of ZnO films has been investigated. X-ray diffraction patterns show that crystallinity of the ZnO films
has been improved after annealing. The morphology of ZnO thin films is studied by atomic force microscopy. The tensile strain
(compressive stress) is found to decrease with increase in annealing temperature which indicates the relaxation of tensile
strain in ZnO thin films. A decrease in energy band gap is observed with increase of annealing temperature. The mechanism
of blue-green luminescence of ZnO thin film has been analyzed. The resistivity is found to decrease with annealing temperature. 相似文献