Electroanalytical Studies and Simultaneous Determination of Amlodipine Besylate and Atorvastatine Calcium in Binary Mixtures Using First Derivative of the Ratio‐Voltammetric Methods

The electrochemical behavior of atorvastatin and amlodipine at a glassy carbon electrode has been studied using different voltammetric techniques. First derivative of the ratio voltammetric methods for determination of amlodipine and atorvastatin in tablets in the presence of the other compound has been described. This technique depends on the measuring of first derivative of the ratio voltammograms of each concentration as a function of the increased concentrations. DP and SW voltammetric methods depend on first derivative of the ratio‐voltammetry by measurements of the selected potentials for amlodipine and atorvastatin. The linear response was within the range of 4×10^?6–1×10^?4 M for amlodipine and 2×10^?6–1×10^?4 M for atorvastatin. The proposed methods have been extensively validated.     

Effects of annealing and high radiation dose on the thermoluminescence characteristics of natural fluorite

In this study, the various dosimetric properties of the thermoluminescent (TL) phosphor of CaF₂:natural including response characteristics, sensitivity to thermal annealing and decay of stored energy were investigated in detail. The analysis of the peak temperature values and the half widths of the resolved components in the glow curves, by using the Computerized Glow Curve Deconvolution (CGCD) Method, resulted in the activation energy (E) of 0.85–1.83 eV and frequency factor (s) of 6.17E+9–2.90E+15 s^?1. The effects of pre-irradiation thermal annealing on the radiation-induced sensitization of the thermoluminescent response of CaF₂:natural were presented. An enhancement of sensitivity after being subjected to a high beta particle exposure was clarified. The effect was complicated by the influence of heat treatments before the exposure to radiation. Replicate runs on CaF₂:natural after irradiation with 1 Gy absorbed dose indicated good reproducibility of peak temperatures and intensities; they can be re-used for repeated measurements. It appeared that the main dosimetric peak at 280 °C exhibits negligible fading over 4 weeks and may be used for dosimetry. This study has demonstrated that the potential exists for the use of CaF₂:natural for TL radiation dosimetry.     

Alloying effects on Kβ/Kα intensity ratios and electrical properties in Cd1−xZnxS semi-conductor alloys

The alloying effect on K_β/K_α intensity ratio in Cd_1−xZn_xS semi-conductor alloys and on structural, electrical and optical properties of these alloys were investigated. The sample was excited by gamma rays with energy 59.5 keV photons from an Am-241 radioisotope source. K X-rays emitted by the sample were counted with a Si(Li) detector. We found that the K_β/K_α intensity ratio is changed by the alloying effect in Cd_1−xZn_xS semi-conductor alloys for different compositions x. We compared our results with the theoretical values.     

Synthesis and Characterization of Novel N-, S-, O-Substituted P-Chloranil Derivatives

A series of novel N-, S-, and O-substituted p-chloranil derivatives were synthesized from the reactions of p-chloranil (1) and related nucleophiles in sodium carbonate (Na₂CO₃) solution of acetonitrile or in chloroform with Et₃N. The structures of novel compounds were characterized by using microanalysis, Fourier transform–infrared, ¹H NMR, ¹³C NMR, and mass spectrometry.     

Surface tension estimation of high temperature melts of the binary alloys Ag–Au

Abstract

Surface tension calculation of the binary alloys Ag–Au at the temperature of 1381 K, where Ag and Au have similar electronic structures and their atomic radii are comparable, are carried out in this study using several equations over entire composition range of Au. Apparently, the deviations from ideality of the bulk solutions, such as activities of Ag and Au are small and the maximum excess Gibbs free energy of mixing of the liquid phase is for instance ?4500 J/mol at X_Au = 0.5. Besides, the results obtained in Ag–Au alloys that at a constant temperature the surface tension increases with increasing composition while the surface tension decreases as the temperature increases for entire composition range of Au. Although data about surface tension of the Ag–Au alloy are limited, it was possible to make a comparison for the calculated results for the surface tension in this study with the available experimental data. Taken together, the average standard error analysis that especially the improved Guggenheim model in the other models gives the best agreement along with the experimental results at temperature 1383 K although almost all models are mutually in agreement with the other one.     

Phase Transition of Mixed Type <Emphasis Type="Italic">p</Emphasis>-Adic λ-Ising Model on Cayley Tree

In the present paper, we consider an interaction of the nearest-neighbors and next nearest-neighbors for the mixed type p-adic λ-Ising model with spin values {?1, +1} on the Cayley tree of order two.We obtained the uniqueness and existence of the p-adic quasi Gibbs measures for the model. Thereafter, as a main result, we proved the occurrence of phase transition for the p-adic λ-Ising model on the Cayley tree of order two. To establish the results, we employed some properties of p-adic numbers. Therefore, our results are not valid in the real case.     

Vergleich von Röntgen- und optischer Emissionsspektralanalyse mit der Glimmlampe bei Anwendung auf AgCu-Binärlegierungen

For the binary eutectic system AgCu, calibration curves are established over a large concentration range (0.3–99.7%). These calibration curves are bent in X-ray spectrochemical analysis as well as in optical emission spectral analysis with a glow discharge lamp as a result of matrix effects. Linearization is achieved by the “method of binary ratios.” By making use of this simple calibration method, it is possible to obtain results with high precision and accuracy: the relative S. D. depends on concentration and is approximately 0.05(1?c). Both methods of spectrochemical analysis are therefore suitable (at least for binary systems) for the determination of major and minor constituents.     

Measurement of K to L shell vacancy transfer probabilities for the elements 52?Z?68

The probabilities for transfer of vacancies from K to L shell were measured using intensity ratio of K_α and total L_x X-rays. The K_α and total L_x X-rays yields from the targets excited by incident photon were obtained using a Si(Li) detector. These experimental results were compared with the theoretically calculated values using radiative and radiationless transitions. The radiative transitions of these elements were observed from the relativistic Hartree-Slater model, which was proposed by Scofield (Atom. Data Nucl. Data Tables 14 (1974) 121). The radiationless transitions were observed from the Dirac-Hartree-Slater model, which was proposed by Chen et al. (Atom. Data Nucl. Data Tables 24 (1979) 13). A fairly good agreement is found between the experimental and calculated values.