Showing papers by "Jadavpur University published in 1978"
TL;DR: In this article, the first-order topology of a chemical graph of a molecule is established and an equivalence relation is defined on the set of vertices of this graph to get the disjoint classes of equivalent atoms in the configuration, and with the help of Shannon's formula, the firstorder topological information contents of such molecules are calculated.
Abstract: In this paper an effort has been made to obtain the topological information content of (i) the four bases of DNA and uracil, (ii) the nucleotides of DNA and RNA, (iii) the 64 nucleotide triplets of RNA and (iv) the twenty amino acids. By defining first-order neighborhoods of the vertices of the chemical graph of a molecule, a topology is established (which may be termed first-order topology). An equivalence relation is thereafter defined on the set of vertices of this graph to get the disjoint classes of equivalent atoms in the configuration, and with the help of Shannon's formula [19], first-order topological information contents of such molecules are calculated. From this measure of information content it appears that the topological information content, rather than the non-topological one, is more pronounced for bases of nucleic acids as well as for nucleotides. This result may give a clearer picture of information processing at the cellular level of a living system.
62 citations
TL;DR: In this article, the application of integral approach to the numerical computation of fields in a multi-dielectric, three-dimensional system was described and the accuracy of the method has been studied by taking a simple example of parallel-plate electrodes containing two-layer dielectrics.
Abstract: The paper describes application of integral approach to the numerical computation of fields in a multi-dielectric, three-dimensional system. The accuracy of the method has been studied by taking a simple example of parallel-plate electrodes containing two-layer dielectrics. The use of fictitious point charges has been found to be quite successful in the analysis of fields in and around a disc insulator. The effect of varying dielectric constant of the insulating material on the field distribution has also been determined.
39 citations
TL;DR: The development of the theory of electron capture processes in ion-atom collisions is reviewed in this paper, where the formal theory of scattering is used to obtain the Born and the distorted wave Born series for the rearrangement scattering matrix.
37 citations
TL;DR: In this article, the polarity of the solvent and the availability of protons in the solvent have been investigated for photo-sensitized I-ion oxidation by singlet oxygen.
Abstract: — Iodide ion oxidation by singlet oxygen is found to be influenced by two properties of the solvent. One is the polarity of the solvent and the other is the availability of protons in the solvent. By suitable choice of solvents and solvent mixtures both kinds of effects have been studied. In water-methanol mixtures the reaction is found to be facilitated in more polar medium. In isodielectric media as obtained by mixtures of acetonitrile and methanol the reaction is repressed with increase in the aprotic component (CH3CN) in the solvent. The same effect is observed in the DMSO-H, O mixtures. In heavy water the reaction rate is doubled and the effect fits well into the proposed kinetic scheme involving singlet oxygen for photosensitized oxidation of I- by anthracene sulphonates.
35 citations
TL;DR: An active grounded inductance using a single second generation current conveyor (CC II) as the active element and three passive components is proposed and seen to be suitable for moderate-Q applications.
Abstract: An active grounded inductance using a single second generation current conveyor (CC II) as the active element and three passive components is proposed. The inductance is seen to be suitable for moderate-Q applications. For high-Q with independent Q-controlled inductances suitable circuit techniques pertaining to the introduction of a second CC II as a voltage follower are also presented.
29 citations
01 May 1978
TL;DR: In this paper, four new active integrator configurations are reported, all of which use single grounded capacitors, and all of them use single-ground capacitors for active integration.
Abstract: Four new active integrator configurations are reported. All the circuits use single grounded capacitors.
19 citations
01 Dec 1978
TL;DR: In this article, a bilinear RL impedance using only one operational amplifier and one or two resistors is proposed, based on the single-pole model of the OA.
Abstract: Realization of bilinear RL impedances use only one operational amplifier (OA) and one or two resistors is proposed. These are based on the single-pole model of the OA. Applicabilities of these one-port active-R grounded inductances in a parallel capacitor tuned high-Qresonator and in a new external capacitorless sine-wave oscillator are also reported tosether with experimental verification.
18 citations
TL;DR: In this paper, the isolation and characterization of dipositive metal ions-ATP complexes have been described and the isolated solid compounds have the composition Na2M(ATP)nH2O where n = 2 for M = Ca(II), Mn(II, Fe, Co, Zn, and VO2+; n = 3 for Mg(II) and n = 4 for M
16 citations
TL;DR: In this paper, a new grounded-capacitor simulation of driving-point impedances of the form as and bs2, corresponding to ideal inductance and frequency-dependent negative resistance (f.n.c.s/d.v.r.) elements, respectively, is presented.
Abstract: A new grounded-capacitor simulation of driving-point impedances of the form as and bs2, corresponding to ideal inductance and frequency-dependent negative resistance (f.d.n.r.) elements, respectively, is presented. The configurations use the minimum of passive components with the d.v.c.c.s./d.v.c.v.s. as the active element. Applications of the active inductance and f.d.n.r. are then proposed in the realisation of some single-resistor-controlled RC oscillators.
15 citations
TL;DR: In this article, the degradation of dilute solutions of d -fructose and d -glucose undergo alkaline degradation, and, at temperatures in the range of 30-70°, almost two moles of alkali are consumed per mole of the carbohydrate.
14 citations
TL;DR: This investigation has indicated that the 2-position of the triglyceride is preferentially esterified with C18 unsaturated acids and linoleic acid shows preference over oleic acid.
Abstract: Fatty acid and triglyceride compositions of Entada phaseolides seed oil have been determined by combination of the techniques of systematic crystallisation at low temperatures, pancreatic lipase hydrolysis and gas-liquid chromatography of methyl esters. The percentages of individual fatty acids were found to be myristic 0.3, palmitic 9.1, stearic 4.4, arachidic 1.7, behenic 1.6, oleic 35.8, linoleic 46.7 and linolenic 0.4. The special characteristic of this oil is its content of 6.9, 9.6, 17.0, 19.2, 5.0, 24.1 and 10.4% of monosaturated diolein, monosaturated dilinolein, saturated oleo linolein, dioleo-linolein, triolein, oleo dilinolein and trilinolein, respectively. This investigation has indicated that the 2-position of the triglyceride is preferentially esterified with C18 unsaturated acids and linoleic acid shows preference over oleic acid.
TL;DR: It is concluded that 2-aminocrotonate is the intermediate which serves as a source of reducing equivalent for ferricyanide, and nonstoichiometric amount of ferRICyanide reduction may be attributed to some secondary reactions of ferricsyanide with compounds derived from the oxidation product of 2-amines.
Abstract: The threonine-dependent reduction of ferricyanide catalyzed by the purified biodegradative threonine dehydratase of Escherichia coli has been studied. The rate of production of 2-oxobutyrate in the presence of ferricyanide was lower than that found in the absence of ferricyanide. The concentrations of threonine required for half-maximal effects for the reduction of ferricyanide and, in the presence of the dye, for 2-oxobutyrate production, were 3 mM and 9 mM, respectively. Reduction of ferricyanide was accompanied by evolution of CO2, and even within a very short in cubation time with the enzyme, the ratio of ferricyanide reduced over CO2 evolved was approximately 7. Stopping the enzyme activity after a brief exposure to threonine at pH 9.7 resulted in the accumulation of an intermediate (with a half-life of 4 min at 25°C) which formed an adduct with N-ethylmaleimide; the accumulated intermediate, in the absence of N-ethylmaleimide, reduced ferricyanide with concomitant evolution of CO2. We conclude from these results that 2-aminocrotonate is the intermediate which serves as a source of reducing equivalent for ferricyanide, and nonstoichiometric amount of ferricyanide reduction may be attributed to some secondary reactions of ferricyanide with compounds derived from the oxidation product of 2-aminocrotonate.
TL;DR: In this paper, the effect of acetylated castor oil as an internal plasticizer on the resulting urethane films has been studied, showing good tensile strength (105-550 kg/cm2) and elongation (15-215%) properties.
Abstract: Moisture-cured polyurethane films have been prepared by reaction between toluene diisocyanate and castor oil or derivatives such as castor oil diethanol amide, castor oil monoglyceride, ethylene glycol monoricinoleate, and propylene glycol monoricinoleate. Effect of acetylated castor oil as an internal plasticizer on the resulting urethane films has been studied. Catalytic effect of 3-5% triethanol amine on curing of plasticized films has been noted. Plasticized polyurethane films show good tensile strength (105-550 kg/cm2) and elongation (15-215%) properties, having high melting point (210-272 C) and good resistance to solvents and chemicals.
TL;DR: In this article, a method for altering the resonant length of a square micro-strip antenna is described, and the relevant analysis and computations have been carried out to propose a possibility of realising a microstrip antenna having comparatively smaller dimensions and larger bandwidth.
Abstract: A method for altering the resonant length of a square micro-strip antenna is described. The relevant analysis and computations have been carried out to propose a possibility of realising a microstrip antenna having comparatively smaller dimensions and larger bandwidth.
TL;DR: In this paper, a method for deriving the effective pair potential for fluids from static structure factor data is discussed, and the potentials derived are compared with those given by Shyu et al. for sodium and Alder et al for argon.
TL;DR: In this article, a paratectonic porphyroblast can show one or two reversals in the spiral direction, which corresponds to a stage when the porphyroid and the external foliation were rotating at the same rate.
TL;DR: In this paper, the Fatty acid and triglyceride compositions of phulwara butter (Madhuca butyraceae seed fat) have been determined by combination of the techniques of systematic crystallization at low temperatures, pancreatic lipase hydrolysis, and gas liquid chromatography of methyl esters.
Abstract: Fatty acid and triglyceride compositions of phulwara butter (Madhuca butyraceae seed fat) have been determined by combination of the techniques of systematic crystallization at low temperatures, pancreatic lipase hydrolysis, and gas liquid chromatography of methyl esters. The percentages of individual fatty acids were found to be palmitic, 55.6; stearic, 5.2; oleic, 35.9; and linoleic, 3.3. The special characteristic of the phulwara butter is its content of POP, 52.5%; PLP, 4.9%; POSt, 8.6%; POO, 14.4% and PPP, 7.7% (P, palmitic; St. stearic; O, oleic; and L, linoleic). 2-Monoglycerides obtained by lipolysis of this fat and its least soluble fraction contained 13,0% and 29.3% saturated acids, respectively. Phulwara butter may be a potential source of palmitic acid for the pharmaceutical industry.
TL;DR: In this paper, a minimal active-circuit realisation of a 3rd-order lowpass Butterworth characteristic using second-generation current conveyors as the active elements is proposed.
Abstract: A minimal active-circuit realisation of a 3rd-order lowpass Butterworth characteristic using second-generation current conveyors as the active elements is proposed. The network parameters have low passive sensitivities and are practically insensitive to active parameter changes. The configuration is attractive for i.e. fabrication in that the passive components are all of equal value and the capacitors are earthed.
TL;DR: In this article, the authors studied the kinetics of the oxidation of arsenite ion by platinum(IV) in basic solutions at several temperatures and showed that the rate increases with increase in pH as well as salt concentration and dielectric constant of the medium.
TL;DR: In this paper, the conditions for natural mode oscillations for a class of active RC circuit configurations are analyzed and realizability conditions for a number of configurations are derived showing independent control of the condition of oscillation mid frequency tuning by means of single elements.
Abstract: The conditions for natural mode oscillations for a class of active RC circuit configurations are analysed. Realizability conditions for a number of configurations are derived showing Independent control of the condition of oscillation mid frequency tuning by means of single elements. In addition, low frequency generation is possible without requiring large values of RC elements. The circuits, therefore, are suitable for adoption to HIC techniques, in which event the stability of oscillation frequency would also improve
TL;DR: In this article, Chakraborty and Niyogi pointed out a sign error in the second formulation of Ntfrstrud and indicated an alternative way of obtaining the appropriate formulation for this case.
Abstract: Introduction T are at present three different integral equation formulations for studying the direct problem of steady inviscid isentropic transonic flow past thin lifting profiles, where the freestream Mach number M^ (< 1) and the body shape are prescribed. Two of these formulations are by Ndrstrud,' and the third is by Nixon and Hancock. The formulation in Ref. 2 has been extended to the threedimensional case of lifting wings by N^rstrud. The basic integral equation governed by the perturbation potential of a lifting wing was given earlier by Heaslet and Spreiter and Klunker. About two years ago, a controversy started from a criticism by Nixon regarding the correctness of the formulation of N^rstrud which, according to Nixon, leads to nonunique solution. Ntfrstrud, on the other hand, pointed out some mistakes in the Nixon critique, creating further confusion. Recently, Chakraborty and Niyogi showed that the formulations of Nefrstrud and Nixon and Hancock are equivalent. The purpose of the present Note is to point out a sign error in the second formulation of Ntfrstrud and to indicate an alternative way of obtaining the appropriate formulation for this case.
01 Jul 1978
TL;DR: In this article, a grounded capacitor network was analyzed to yield either a bandpass or a low-pass function by adjustment of a single resistor, and the experimental results were quite in agreement with the analysis.
Abstract: Using the single-pole model of the operational amplifier (OA) a grounded capacitor network has been analyzed to yield either a bandpass or a low-pass function by adjustment of a single resistor. The bandpass/low-pass filters are suitable for high selectivity applications at extended frequency ranges with the advantage of independent adjustment of pole-frequency, pole-Q factor, and midband/passband transmission gain. The network has low sensitivity to all the circuit parameters. The experimental results are quite in agreement with the analysis.
Journal Article•
TL;DR: The chromitite lodes are emplaced in serpentinites as banded layers, lenses or clots as mentioned in this paper, and the ores are high alumina chromite with RO:R 2 O 3 ranging from 0.92 to 1.08 and formed by magmatic segregation.
Abstract: The chromitite lodes are emplaced in serpentinites as banded layers, lenses or clots. The ores are high alumina chromite with RO:R 2 O 3 ranging from 0.92 to 1.08 and formed by magmatic segregation. Hydrothermal alteration has produced different chrome-bearing silicates like kammererite, uvarovite, chrome-amphibole, and chrome-bearing chalcedony, which occur either as transgressing veinlets in chromitites or in the interspaces between chromite grains. The primary dunite-peridotite has been altered to massive and compact serpentinite.
TL;DR: The method is simple, rapid and quantitative over a wide range of acidity (1-4N sulphuric acid) and is superior to existing gravimetric methods and works satisfactorily for determining tin in brass and bronze.
TL;DR: UDPglucose 4-epimerase from Saccharomyces fragilis shows Michaelis kinetics with UDPgalactose as the substrate and allosteric kinetics in the normal fashion and when desensitized enzyme is used or when allostericity is abolished with high concentrations of cation, the equilibrium is established in thenormal fashion.
TL;DR: In this paper, a gravimetric reagent for the determination of rhenium (4-50 mg) in the presence of 0.7-1.7 M hydrochloric acid and tin(II) chloride was proposed.
TL;DR: In this article, a two-dimensional idealized analysis leading to the shortcircuit current, open-circuit voltage, conversion efficiency and spectral response of a typical cell is presented.
Abstract: Due to rapid diffusion of externally applied copper along the disordered region of the grain boundaries, the skin region of the Cu x S-CdS solar cell consists of alternate layers of thick and thin regions of p-Cu x S. A two-dimensional idealized analysis leading to the short-circuit current, open-circuit voltage, conversion efficiency and spectral response of the cell is presented. For a typical cell, the variations of these parameters with grain size and width of the disordered regions are shown. It was pointed out that for such a cell, there is an optimum crystallite size for maximum conversion efficiency of the cell. The spectral response characteristics shows a relative improvement in the low-frequency side with increase in density of the CdS crystallites. This is probably due to the vertical junctions formed at the disordered regions.