Showing papers by "Jadavpur University published in 1985"
TL;DR: The thermodynamic and spectrophotometric properties of these complexes suggest that PSF forms a strong charge-transfer complex with Triton X-100 whereas the interaction of PSF with SLS is coulombic in nature.
64 citations
TL;DR: In this paper, it was shown that the mixing is strongly suppressed in the Standard Model and is smaller than the current experimental upper bound, which indicates the existence of a new physics beyond the standard model.
Abstract: It is shown that the\(D^0 - \bar D^0 \) mixing is strongly suppressed in the Standard Model and is smaller by several orders of magnitude than the current experimental upper-bound. The detection of a stronger\(D^0 - \bar D^0 \) mixing in the future experiments might indicate the existence of a new physics beyond the Standard Model. As an example, it is shown that in a class of simple super-symmetric theories\(D^0 - \bar D^0 \) mixing could be substantially larger than the Standard Model prediction. If on the other hand the Standard Model prediction is confirmed by future experiments that will require that the super-symmetric extension of the standard model should have a much larger SUSY breaking scale than that indicated by the phenomenology of the neutral kaon system.
46 citations
TL;DR: In this paper, the uniqueness of the solution of a homogeneous vector-matrix differential equation has been established by the method of eigenfunction approach for both the cases when the roots of the characteristic equations are distinct and when they are repeated.
39 citations
TL;DR: In this article, a set of physical constants for In 0.53 Ga 0.47 As as required for transport calculations is obtained by reviewing the literature, and velocities for fields up to 100 kV/cm, calculated by the Monte Carlo method using these constants, are presented for the temperatures of 95 and 300 K.
Abstract: A set of physical constants for In 0.53 Ga 0.47 As as required for transport calculations is obtained by reviewing the literature. Velocities for fields up to 100 kV/cm, calculated by the Monte Carlo method using these constants, are presented for the temperatures of 95 and 300 K. The calculated values are found to be in good agreement with the available experimental results.
35 citations
TL;DR: In this paper, the optical gaps were determined from the absorption spectrum of the InSe films heat treated at different temperatures and for different periods of time, in terms of density of states model of Mott and Davis and explained as due to the saturation of bonds in the amorphous solid.
34 citations
TL;DR: In this paper, a low-loss splicing method, based on discharge fusion of optical fibers by a simple apparatus and by applying pressure between fibers before fusion, was developed for better end preparation having low initial alignment losses at critical pressure and temperature.
Abstract: A low-loss splicing method, based on discharge fusion of optical fibers by a simple apparatus and by applying pressure between fibers before fusion, was developed. Average splice losses of about 0.07 and 0.15 dB for single-mode (SM) fibers having core diameters of 10 and 7μm, respectively, and 0.02 dB for 50-μm core diameter graded-index (GI) fibers are obtained. Fusion loss and fusion time are obtained minimum for better end preparation having low initial alignment losses at critical pressure and temperature. Mathematical expressions for the variation of fusion time and splice loss with effect of applied pressure between the fibers, for different practical axis alignment, showing the optimum condition to have minimum splice loss are made. Experimental fusion losses are analyzed in terms of residual misalignment of off axis, angular tilt of the fibers during aligning, and air gaps in the splicing zone. Optimum fusion time is obtained by considering the forces due to applied pressure, thermal expansion, and surface tension in the viscous melted glass of the fiber. Theoretical curves of fusion times and splicing losses versus applied pressure agree with the experimental results. The decrease of fusion time to about 1.3 times and splice loss to about two times were found when applied pressure is varried from low to its critical value of 20-25 g. The splice losses are found at a minimum for the operating temperature range of 1980°C to 2140°C for silica fibers. Experimental results of the histogram of bar chart of splice losses agree with the derived mathematical expressions assuming a statistical distribution function of splice losses.
24 citations
TL;DR: In this article, an empirical model of simultaneous buckling and flattening in which the central surface of the folded layer remains a sine curve in transverse profile, the ratio of rates of buckle shortening to homogeneous strain is proportional to sin 2a, with a as the dip angle and the progressive deformation is coaxial with the Z-axis of bulk strain parallel to the planar segments of the early folds.
23 citations
21 citations
TL;DR: It has been proved that the slant transform is superior to Walsh-Hadamard transform in this relative performance measure for positive correlation under the assumed Markov process model.
17 citations
TL;DR: On montre que le probleme inverse correspondant a une condition aux limites periodiques est defini sur une surface de Riemann avec une differentielle abelienne proprement definie.
Abstract: The periodic ``soliton'' solutions of the mixed nonlinear Schr\"odinger equation are analyzed following a method advocated by Date. The inverse problem corresponding to a periodic boundary condition is shown to be defined on a Riemann surface, with a properly defined Abelian differential. The general solution corresponding to the n zone is given in terms of the Riemann theta function.
13 citations
TL;DR: Streptomyceskanamyceticus produces a significant level of intracellular glucose isomerase when grown in submerged culture, and treatment of cells with cetyl trimethyl ammonium bromide extracts almost the same amount of the enzyme as ultrasonic treatment.
Abstract: Streptomyceskanamyceticus produces a significant level of intracellular glucose isomerase when grown in submerged culture. The optimum temperature for enzyme activity is 90°C, but the optimum pH is changed by the kinds of buffer solution used. The activity is higher at pH 7.0–9.5. Treatment of cells with cetyl trimethyl ammonium bromide extracts almost the same amount of the enzyme as ultrasonic treatment. The selection of the method of treatment for enzyme extraction depends, however, on the nature of cell growth in synthetic or complex medium.
TL;DR: In this article, an attempt has been made to consider the thermal effect on the transverse vibration of a high-speed rotating disk in a steady-state heat conduction and a new critical speed of disk rotation has been obtained and consequently this critical speed is found to depend on central temperature, thermomechanical anisotropy, and so forth.
Abstract: An attempt has been made to consider the thermal effect on the transverse vibration of a high-speed rotating disk in a steady-state heat conduction. The material of the disk, in this case, is assumed to be thermomechanically anisotropic. The present attempt is made with an objective to provide some theoretical studies on the problem that may serve as a base from which more detailed investigations with regard to the usage of composite material may be attempted to gain new andneeded design information regarding turbine disks and thereby to reduce the chances of turbine failure. In this connection a new critical speed of disk rotation has been obtained and consequently this critical speed is found to depend on central temperature, thermomechanical anisotropy, and so forth. 19 references.
TL;DR: Triphenylphosphine-cyanoborane has been very conveniently prepared in high yield by the reaction of NaBH3CN with triphenylPHosphine hydrochloride in refluxing tetrahydrofuran as mentioned in this paper.
Abstract: Triphenylphosphine-cyanoborane has been very conveniently prepared in high yield by the reaction of NaBH3CN with triphenylphosphine hydrochloride in refluxing tetrahydrofuran, and triphenylphosphine-dichloro- and dibromoboranes have been prepared by halogenation of the precursor triphenylphosphine-borane with free halogen respectively in carbon tetrachloride and dichloromethane. These compounds were characterized by elemental analysis, and infrared and proton NMR spectra.
TL;DR: In this article, the authors studied the kinetics of methanol and mono-deutero-methanol in perchloric acid medium at constant ionic strength (μ = 1.0 M) adjusted with sodium perchlorate.
TL;DR: Bianchi type-Icosmological models are discussed in the Bergmann-Wagoner-Nordtvedt scalar-tensor theory where both the so-called cosmological constant ..lambda.. and the coupling parameter ..omega.. are taken to be functions of the scalar field phi.
Abstract: Bianchi type-I cosmological models are discussed in the Bergmann-Wagoner-Nordtvedt scalar-tensor theory where both the so-called cosmological constant \ensuremath{\Lambda} and the coupling parameter \ensuremath{\omega} are taken to be functions of the scalar field \ensuremath{\varphi}. Exact solutions are obtained in Dicke's revised units assuming a very simple relationship between \ensuremath{\Lambda} and \ensuremath{\varphi}. The properties of the models are discussed in special cases.
TL;DR: In this article, the kinetics of oxidation of d -glucopyranose 6-phosphate and d -ribofuranose 5-phophosphate by chromium(VI) in perchloric acid media have been studied by u.v. spectroscopy.
TL;DR: The new molybdenum cyanonitrosyl complexes, R2[Mo(NO)(CN)5]·2H2O (R = Ph4P and Bu4N) and [Mo(No)(CN)3(L-L)]·H 2O [L -L =
TL;DR: In this paper, a simple, sensitive and selective method for the determination of trace amounts of the metal in 50% ethanolic medium was developed for the analysis of synthetic mixtures with 3-(2-hydroxyphenyl)-1-phenyltriazene-Noxide.
Abstract: The fact that niobium gives orange fluorescence (λ
ex
max
570, λ
em
max
540 nm) in both acid and alkali media with 3-(2-hydroxyphenyl)-1-phenyltriazene-N-oxide, has been exploited to develop a simple, sensitive and selective method for the determination of trace amounts of the metal in 50% ethanolic medium. Measurements are made at the pH range of 3.2–5.0. Fluorescence intensity attains the maximum value after 45 min of standing and remains almost unchanged after 24 h. Calibration graph maintains linearity from 50 ppb to 2.2 ppm of the metal. Forty cations and anions are without any effect on the fluorimetric determination of niobium(V). The method has been applied to the analysis of synthetic mixtures.
TL;DR: In this article, the atomic scattering factor fh for elastic scattering of electromagnetic radiation depends strongly on electronic charge distribution n(r) in the atom, and it has been shown that the superposition of free-atom charge densities through Lowdin's α-expansion can help to find n r in a solid, which, in turn, yields a reasonable metallic cohesive energy and binary alloy formation energy.
Abstract: The atomic scattering factor fh for elastic scattering of electromagnetic radiation depends strongly on electronic charge distribution n(r) in the atom. Deviations of recently measured fh's from those calculated from free-atom electron states confirm the notion that n(r) gets appreciably modified in a solid. Recently it has been shown that the superposition of free-atom charge densities through Lowdin's α-expansion can help to find n (r) in a solid, which, in turn, yields a reasonable metallic cohesive energy and binary alloy formation energy. Here it is shown that the same procedure produces fh values that compare well with experiments as well as with more sophisticated band calculations.
TL;DR: The principle of equivalence of general theory of relativity provides the possibility of studying rotation at uniform rates about a fixed axis with the help of transformation from an inertial laboratory frame to frames having such rotation as mentioned in this paper.
TL;DR: In this article, the modified Brans-Dicke theory is applied to homogeneous isotropic cosmologies in the presence of a cosmological constant A and a class of exact solutions are obtained in Dicke's revised units for empty space as well as for the models filled with dust or radiation.
Abstract: Homogenous isotropic cosmologies in the presence of a cosmological constant A are studied in the modified Brans-Dicke theory. A class of exact solutions are obtained in Dicke's revised units for empty space as well as for the models filled with dust or radiation. Behaviour of these models near the singularity are discussed.
Abstract: The consideration of two-body central forces cannot explain the correct ordering of dispersion branches in the I'KM direction in many h.c.p. metals. The importance of three-body forces in these metals is also indicated by the fact that for these metals the sum rule of Waren is not satisfied. Pseudopotential theory demonstrates that the total energy of a metal consists of an effective two-body central interaction and a purely volume dependent part. Starting from this basis, a model expression for the energy of a metal is developed. It is shown that the interpretation of the volume strain as the local strain, as demanded by the adiabatic hypothesis, leads to an effective three-body interaction between the ions. The model is applied to study the lattice dynamics of Mg and Be. It is found that the model predicts the correct ordering of the dispersion branches and fairly good agreement is obtained in the case of phonon frequencies and elastic data.
Die Betrachtung von Zwei-Korper-Zentralkraften konnen nicht die richtige ordnung der Dispersionszweige in der I'KM-Richtung in vielen h. d.p. Metallen erklaren. Die Bedeutung von Dreikorperkraften in diesen Metallen wide auch durch die Tatsache deutlich, das fur diese Metalle die Summenregel von Waren nicht erfullt ist. Pseudopotentialtheorie demonstriert, das die Gesamtenergie eines Metalls aus einer effektiven Zwei-Korper-Zentralwechselwirkung und einem reinen volumenabhangigen Anteil besteht. Ausgehend von dieser Basis, wird ein Modellausdruck fur die Energie eines Metalls entwickelt. Es wird gezeigt, das die Interpretation der Volumen-Drei-Korper-Wechselwirkung zwischen den Ionen Fuhrt. Das Modell wird auf die Untersuchung der Gitterdynamik von Mg und Be angewendet. Es wird gefunden, das das Modell die richtige Ordnung des Dispersionszweigen vorhersagt und es wird eine befriedigend gute Ubereinstimmung fur die Phononenfrequenzen und elastischen Daten erhalten.
TL;DR: In this article, the degree of equilibrium attained with respect to oxygen during metamorphism of non-carbonatic manganiferous sediments and the nature of mobility of oxygen in rocks of adjacent beds by measuring the composition of coexisting phases were determined.
Abstract: This paper aims to ascertain the degree of equilibrium attained with respect to oxygen during metamorphism of non-carbonatic manganiferous sediments and the nature of mobility of oxygen in rocks of adjacent beds by measuring the composition of coexisting phases. Through algebraic analysis of the relevant phase equilibria, a difference of ≃17 kcal in \(u_{{\text{O}}_{\text{2}} } \) in rocks of adjacent beds is obtained. This confirms the immobile nature of oxygen during metamorphism of manganiferous sediments.
TL;DR: In this paper, the effects of different intraperitoneal doses of MT81 (2.5 mg/kg, 5.0 mg/ kg and 7.5mg/kg) for a 2-week, 4-week and 6-week treatment on concentration of total lipid and its different fractions of liver, brain, kidney, testis and serum in mice were studied.
TL;DR: A modified column system, consisting of a post-separator column packed with Vydac CX cation-exchange resin placed between a Dionex separator column for cations and a suppressor column, was able to separate a nine-component mixture of Na(+), K(+).
TL;DR: In this paper, the characteristics of second harmonic generation due to hot electrons in semiconductors have been investigated with due regard to the recombination mechanisms and the results show that recombination effect brings in significant changes in the characteristics.
TL;DR: The in vitro release rate studies of Sulfasomidine from the micropelleted dosage form revealed that the drug release can be prolonged upto eight hours and not more than 39% of the embedded drug released in the first hour of the in vitro dissolution study.
Abstract: A controlled release oral drug delivery system of Sulfasomidine was developed by spray congealing micropelleting technique using gelatin as the embedding matrix. The pellets were hardened by treating with Formalin-Isopropanol mixture. The in vitro release rate studies of Sulfasomidine from the micropelleted dosage form, revealed that the drug release can be prolonged upto eight hours and not more than 39% of the embedded drug released in the first hour of the in vitro dissolution study. The in vitro release patterns correlated with the reported in vivo studies. The method of formulation was optimized.
TL;DR: In this paper, the square modulus of the S state wave function of the neutron, the electric dipole moment |dne| and its baryon number violating lifetime have been estimated.
Abstract: Using the statistical model to arrive at |ψ(r)|2 the square modulus of theS state wavefunction of the neutron, the electric dipole moment |dne| of the neutron as well as its baryon number violating lifetime have been estimated. The baryon asymmetry of the universe depending on |dne| has also been studied in this context.
TL;DR: In this article, the numerical results of a rearrangement charge transfer process calculated by direct application of relativistic Quantum Electro-dynamics in the Lorentz gauge were reported.
Abstract: We report the numerical results of a rearrangement charge transfer process calculated by direct application of relativistic Quantum Electro-dynamics in the Lorentz gauge. Results for single electron capture by fully stripped Li ions from neutral (1S) Hydrogen show very good agreement with experiments and with Coulomb Born methods for energies above 300 keV.
01 Feb 1985
TL;DR: A new microprocessor-based linear frequency- to-code converter (fDC) is described in this letter, which consists of the microprocessor, memory, only one inverter as interface, and an ingenious software program.
Abstract: A new microprocessor-based linear frequency- to-code converter (fDC) is described in this letter. It consists of the microprocessor, memory, only one inverter as interface, and an ingenious software program. The program execution leads to automatic synchronization and conversion of the input f i to an output code. Conversion time is just equal to the period of the input signal.