Showing papers by "Jadavpur University published in 1987"

A Note on the Heuristic for Replenishment of Trended Inventories Considering Shortages

Abstract: We discuss the inventory replenishment policy for an item having a deterministic demand pattern with a linear (positive) trend and shortages. A heuristic is developed to determine the decision rule for selecting the times and sizes of replenishments over a finite time-horizon so as to keep the total costs minimum. The use of the heuristic is illustrated with a numerical example.

Antiprotozoal activity of diospyrin towards Leishmania donovani promastigotes in vitro

Abstract: Diospyrin, a bis-naphthoquinone derivative, isolated from a plant, known for its antitumour properties against Ehrlich ascites carcinoma in Swiss A mice, exhibits antiprotozoal activity towards L. donovani promastigotes in culture.

An application of an LMS adaptive algorithm for a digital AC bridge

Abstract: This paper describes a new microprocessor controlled ac bridge method using an LMS adaptive algorithm. The main advantages of the method include: (i) the algorithm is simple to implement because no complex computations are actually involved, and (ii) slowly time varying impedances may also be measured or monitored. A realtime implementation of the bridge has been made and test results obtained have been incorporated in the paper.

Granulites in and around the Bengal anorthosite, eastern India; genesis of coronal garnet, and evolution of the granulite-anorthosite complex

Abstract: Granulites occur in and around an anorthosite massif (commonly referred to as the Bengal anorthosite) in eastern India. The central part of the anorthosite is massive in nature with locally developed ‘fluxion structure’ in isolated blocks. Banding in the peripheral part is typical of that of the massif anorthosites of Anderson & Morin. The granulites bear imprints of polyphase deformation, and the xenoliths of granulites within the anorthositic massif maintain their regional structural alignment. The Anorthosite, syntectonic with the second fold movement in the terrane, has developed second generation structures.Hornblende, orthopyroxene, clinopyroxene, plagioclase and quartz with or without garnet and other minor phases consitute the granulites. In the anorthosites, orthopyroxene, clinopyroxene, hornblende, and magnetite with or without garnet may constitute more than 15% of the mode. Garnet, when present in the rocks, is a late overprint. Symplectitic growth of garnet with one or more of the phases such as ilmenite, quartz, clinopyroxene and sodic plagioclase indicates genesis of garnet through decomposition of orthopyroxene and/or prograde hornblende in the presence of calcic plagioclase. The garnet formed during prograde dehydration reactions, rather than cooling of the complex.Chemical characteristics of the mafic phases in the rocks indicate attainment of exchange equilibrium with respect to the major cations in closely associated hornblende, clinopyroxene, orthopyroxene and garnet. Estimated physical conditions of metamorphism from contrasted assemblages suggest a final equilibration of different granulitic assemblages as well as of the anorthositic assemblages under similar conditions. There was, however, belated building up of water pressure in the anorthositic domains stabilizing a late hornblende during cooling of the complex. Absence of chilled margins in the anorthosite as well as absence of contact aureoles in the enveloping and enclosed granulites indicate emplacement of the anorthosite in a hot environment, prior to cooling of the complex.

Biostratigraphy of Jurassic Chari Formation: a study in Keera Dome, Kutch, Gujarat

Abstract: A biostratigraphic subdivision has been proposed in 210 metres-thick Jurassic Chari Pormation exposed around Keera, Kutch. Evaluation of the relevant pieces of earlier works and new findings emerged in course of present study allow establishment of six distinctive assemblage-zones especially on the basis of rich cephatopod biota. These biozones are largely facies transgressive and hence are often not correlatable with lithofacies distribution. A possible correlation between these biozones at Keera and those established in the type section at Jumara, Kutch from the earlier work has also been attempted.

Global stability and oscillations in classical Lotka-Volterra loops

Abstract: The paper considers the classical Volterra system of n (⩾ 3) species in predator-prey relation forming a loop, and derives some global properties of its solutions. Sufficient conditions for global asymptotic stability in terms of parameters are obtained, and also the region of global boundedness in the parameter space is indicated. Lastly a three species system is discussed in detail in relation to its global stability, unboundedness of solutions, existence of periodic and non-periodic oscillations.

Thermally induced phase transition and X-ray crystal structure of bis(N,N′-dimethyl-1,2-ethanediamine)di-isothiocyanatonickel(II)

Abstract: The complex [Ni(MeNHCH2CH2NHMe)2(NCS)2](1) has been synthesised and characterised by X-ray crystallography. It undergoes an irreversible endothermic phase transition (452.5–468.5 K, ΔH= 13.4 kJ mol–1) to species (2) which reverts to (1) in a humid atmosphere. Complex (1) crystallises in the monoclinic space group C2/c with a= 13.069(2), b= 9.783(3), c= 15.074(4)A, β= 111.40(2)°, and Z= 4. The structure has been solved by Patterson and successive Fourier methods and refined to R= 0.032 for 1 240 independent observed reflections. The co-ordination around the nickel atom, lying on a crystallographic inversion centre, is close to octahedral with the two thiocyanate N atoms in trans position. The chelate rings exist in the δλ conformation. For complex (2), a=b= 8.16(3), c= 7.53(2)A, α=β= 107.0(2), γ= 73.6(3)°, and Z= 1. Crystallographic and i.r. spectroscopic data suggest a non-centrosymmetric structure for (2) with a qualitative change in the conformation of the complex to δδ or λλ.

High-field autocovariance coefficient, diffusion coefficient and noise in InGaAs at 300 K

Abstract: Electron diffusivity in In(0.53)Ga(0.47)As is calculated by the Monte-Carlo method. The auto-covariance coefficient and correlation time of velocity fluctuations, frequency dependence of diffusion coefficient and figure of merit for noise are studied. The results indicate that the limiting frequency of operation and noise in In(0.53)Ga(0.47)As Gunn diodes would be comparable to those of GaAs diodes.

Calcutta Pollutants: Part 1: Appraisal of Some Heavy Metals in Calcutta City Sewage and Sludge in Use for Fisheries and Agriculture

Abstract: A chelate extraction procedure followed by atomic absorption spectrometry (AAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) is described for the determination of some heavy metals (Pb, Cu, Zn, Cd, Ni, Co, Mn, Fe and Cr) in sewage and sludge. The procedure is applied to the determination of Calcutta sewage and sludge. The concentration of the above-mentioned heavy metals in Calcutta sewage-sludge is lower in magnitude when compared with that of some cities in other countries.

Chemical Investigations on Celastrus paniculatus Seed Oil I

Abstract: Fatty acid compositions of four lipid fractions of Celastrus paniculatus seed namely normal triglycerides (20.2%), polar triglycerides (44.4%), polar nonglyceridic ester (23.5%), and nonpolar nonglyceridic ester (11.9%), have been determined by gas liquid chromatography. Percentage contents of major component acids in these fractions are: palmitic, 25.1, 42.0, 12.7, 58.2; stearic, 6.7, 4.5, 15.8; oleic, 46.1, 24.8, 4.7, 14.2; linoleic, 15.4, 14.7, 10.0; and linolenic, 3.0, 13.1, 43.0, respectively. The major molecular species constituting the normal triglycerides are: palmitooleopalmitin, 6.8%; palmitooleostearin, 5.6%; palmitodiolein, 14.7; palmitooleolinolein, 7.0%; stearodiolein, 6.1%; triolein, 8.0% and dioleolinolein 7.6%. Lipolysis of the polar triglyceride indicated as high as 59.6% of saturated acids linked to the 2-position of glycerol. Chemische Untersuchungen des Saatols von Celastrus paniculatus I Mit Hilfe der Gaschromatographie wurden die Fettsaure-Zusammensetzungen von vier Lipidfraktionen der Saat von Celastrus paniculatus bestimmt, und zwar normale Triglyceride (20.2%), polare Triglyceride (44.4%), polare nichtglyceridische Ester (23.5%) und nichtpolare nichtglyceridische Ester (11.9%). Die prozentualen Gehalte der Hauptbestandteile der Sauren in diesen Fraktionen sind: Palmitinsaure 25.1, 42.0, 12.7, 58.2; Stearinsaure 6.7, 4.5, 15.8; Olsaure 46.1, 24.8, 4.7, 14.2; Linolsaure 15.4, 14.7, 10.0 und Linolensaure 3.0, 13.1, 43.0. Die Haupttriglyceride, die die normalen Triglyceride ausmachen, sind: Palmitooleopalmitin 6.8%, Palmitooleostearin 5.6%, Palmitodiolein 14.7%, Palmitooleolinolein 7.0%, Stearodiolein 6.1%, Triolein 8.0% und Dioleolinolein 7.6%. Die Lipolyse der polaren Triglyceride ergab 59.6% gesattigte Sauren, die an die 2-Position des Glycerins gebunden sind.

Anisotropic viscous-fluid cosmological model

Abstract: We present exact solutions of a Bianchi type VI0 viscous fluid cosmological model. It is a generalization of the model proposed by Banerjee and Santos (1983) for Bianchi type I.

Kinetics of oxidation of sulphite by hexachloroplatinate(IV) in acidic solution

Abstract: The kinetics of the oxidation of sulphite by hexachloroplatinate(IV) has been studied over wide range of experimental conditions. The reaction is first-order in substrate and in platinum(IV). The rate decreases with the increase in acidity. The effect of salt and of changing dielectric constants on the reaction rate have been studied. Values of ΔH‡ and ΔS‡ have been calculated and are 26.3 kJ mol−1 and −35.9 JK−1 mol−1, respectively. On the basis of experimental evidence, a two-electron reduction mechanism is proposed.

Elastic properties of porous thermosetting polymers

Abstract: A new equationE =E0 (1 −bp)n has been derived semi-empirically to describe the porosity dependence of elastic properties of thermosetting polymers. The material constantb is defined as a “pore distribution geometry factor” and the other material constantn is dependent on pore geometry. The equation shows good agreement with the data on porous polyester and epoxy resins.

Novel frequency-factor method for power-frequency measurement and estimation of load shedding

Abstract: The paper defines a new term called ‘frequency factor’ and develops a method which utilises this factor to detect change in fundamental components of power-system frequency. A straight-line fit algorithm then optimally computes the average frequency deviation and average rate of change of frequency from the oscillatory response of any generator busbar caused by a sudden imbalance in generation and load demand in the system and predicts the amount of load to be shed. Results of computer simulation with a sample power system were also given in the paper.

ON THE STRUCTURE OF π AND K MESONS

Abstract: We have investigated the form factors of the π and K mesons within the framework of the statistical model. Our results reveal several well-spaced minima and maxima for different values of Q2, the square of the momentum transfer. The characteristic features of the elastic differential cross section, dσ/dt, for π±P and K±P scattering data are well reproduced, as a consequence.

A methodology for synthesis of recursive functional programs

Abstract: John Backus introduced the Functional Programming (FP) system, the variable-free applicative system having reduction semantics. Backus has also introduced a unique expansion technique for reasoning about a class of recursive FP programs. As a natural outgrowth of this expansion technique, an FP program synthesis methodology is described in this paper.The methodology synthesizes recursive FP programs of the form f = p →, q; E(f . h) from their preformulated case-by-case descriptions, which in turn come from given input-output example specifications. After explaining the methodology informally, formalization in the form of a definition and a synthesis theorem is introduced. A sufficient condition for the functional form E, for successful synthesis under the present methodology, is obtained structurally. Several illustrative examples of synthesis are also included.

Evidence of multiplicity scaling of medium energy protons emitted in relativistic heavy ion collisions and antiproton annihilation in nuclei.

Abstract: This paper presents an interesting observation, i.e., Koba-Neilsen-Olesen-type scaling in the multiplicity distribution of medium energy protons emitted as a result of $^{12}\mathrm{AgBr}$ (emulsion) and central $^{24}\mathrm{AgBr}$ (emulsion) interactions at 4.5A GeV/c and p\ifmmode\bar\else\textasciimacron\fi{}-AgBr (emulsion) reactions at 1.4 GeV/c. In all cases, the experimental points lie on the universal curve which can be fitted with a Koba-Neilsen-Olesen-type scaling function \ensuremath{\psi}(Z=${\mathrm{n}}_{\mathrm{p}}$/〈${\mathrm{n}}_{\mathrm{p}}$〉)=(4Z+${4\mathrm{Z}}^{3}$-${5\mathrm{Z}}^{5}$+0.${35\mathrm{Z}}^{7}$)exp(-2.957Z). .AE 57Z). .AE

Hollandite and cryptomelane in the manganese oxide deposits of the Sausar Group, India

Abstract: The phase chemistry and the structure of hollandite-cryptomelane series in the Precambrian Sausar Group of India are reinvestigated. The tunnel-cations of the hollandite-cryptomelane series of the present investigation do not show complete exchanges. Crystal symmetry of these minerals is affected by the amounts and the composition of the tunnel cations. With increasing Ba2+ content, symmetry of cryptomelane in Tirodi area changes from tetragonal to monoclinic. These minerals appear to have been formed in a wide range of metamorphic grade from the lowest (chlorite-biotite) to the highest (sillimanite) grades. The local breakdown of hollandite to hausmannite ±Ba-feldspar must have occurred by the change of fO2 condition of the system during metamorphism.

Effect of minerals on glucose isomerase production by Streptomyces kanamyceticus

Abstract: A study has been made of the mineral requirements of Streptomyces kanamyceticus KCC S-0433 for production of glucose isomerase. The optimal concentrations of MgSO4 and K2HPO4 for enzyme production are 0.07% and 0.05%, respectively. The elements Fe, Mn and Zn are required at levels of 10, 3 and 3 mg/l, respectively. Cu, Co and Ca have inhibitory effects on the production of the enzyme.

The Thermodynamic Properties of Liquid Transition and Rare-Earth Metals Based on CHS Model

Abstract: The thermodynamic properties of liquid transition and rare-earth metals are discussed on the basis of CHS model. The validity of the Gibbs-Bogolyubov inequality within the thermodynamic perturbation theory is assumed. The small perturbation term is approximated by s-d hybridisation energy in the atomic sphere approximation. The results indicate that the method yields thermodynamic quantities quite in agreement with the OCP model and much better than corresponding hard sphere results. Unlike the OCP model the expressions are obtainable analytically and in this sense the model is advantageous. The role of charge and packing on entropy calculation is also discussed in some length. Auf der Grundlage des CHS-Modells werden die thermodynamischen Eigenschaften flussiger Ubergangs- und Selten-Erd-Metalle diskutiert. Die Gultigkeit der Gibbs-Bogolyubov-Ungleichheit inner-halb der thermodynamischen Storungstheorie wird angenommen. Der kleine Storungsterm wird durch s-d-Hybridisierungsenergie in der atomaten Kugelapproximation genahert. Die Ergebnisse zeigen, das die Methode thermodynamische Grosen liefert, die vollig mit dem OCP-Modell uberein-stimmen und viel besser als entsprechende Ergebnisse nach dem Modell starrer Kugeln sind. Entgegen dem OCP-Modell sind die Ausdrucke analytisch erhaltlich und in diesem Sinne ist das Modell vorteilhaft. Die Rolle der Ladung und Packung fur die Entropieberechnung wird ebenfalls aus-fuhrlich diskutiert.