Showing papers by "Jadavpur University published in 1993"
TL;DR: In this article, a deterministic inventory model is developed by assuming that the demand rate is stock-dependent and the items deteriorate at a constant rate, and the expression for the average net profit π over one production run is derived and its optimization with respect to the decision variables Q (initial stock) and T (duration of a production cycle) is carried out.
190 citations
TL;DR: A theoretical model of rural-urban migration has been developed with special reference to the informal sector and shows the simultaneous existence of open unemployment and informal sector in the urban area in migration equilibrium.
119 citations
107 citations
TL;DR: Analytical study reveals that soil around the area of effluent dumping point, which is at the middle of the locality, contains a very high concentration of arsenic and copper, which means arsenic concentration in the ground water is very high.
102 citations
TL;DR: In this article, the extent of adsorption of three different proteins, lysozyme, β-lactoglobulin, and hemoglobin, from aqueous solutions to the surface of silica powder have been studied as a function of time for various values of protein concentration, pH, and temperature.
79 citations
TL;DR: In this article, the authors analyzed the possibility of technology transfer from a technologically advanced foreign firm to a domestic firm of a less-developed country when the product market is characterized by Cournot-Nash competition.
74 citations
TL;DR: In this article, the results of fluorescence quenching of 2-anthracene sulphonate by cetylpyridinium chloride in ionic and non-ionic micellar environments are presented.
Abstract: The results of the fluorescence quenching of 2-anthracene sulphonate by cetylpyridinium chloride in ionic and non-ionic micellar environments are presented. The static quenching process (lifetime, 4.5 ns) was exploited to estimate the bimolecular quenching rate constants and binding constants between the probe and the quencher from the Stern—Volmer equation, the aggregation number of the surfactant micelles, and the occupancy number of the quencher in the micelle and the binding constant of the quencher with the micelle from the Encinas—Lissi equation. Both ionic and non-ionic micelles, i.e. cetyltrimethylammonium bromide, sodium dodecylsulphate, Triton X-100, Tween-20, Tween-40, Tween-60 and Tween-80, were employed. In the Tween series (Tween-20 to Tween- 80), the micellar aggregation numbers systematically varied. The average occupancy number of the quencher in the micelle and the binding constant of the quencher with the micelle showed a linear correlation with the aggregation number of the micelles.
60 citations
TL;DR: Two stable 8-quinolinolate complexes of ruthenium(II), [Ru(bpy)(Q)]ClO 4 and [Ru (tap) 2 (Q)]CLO 4 [bpy = 2,2′-bipyridine, Q=8-quinolate anion, tap = 2-(m -tolylazo) pyridine] have been synthesized.
59 citations
TL;DR: In this paper, the visible spectra of safranine T in micellar solutions indicate 1:1 (dye to micelle) charge transfer complex formation with the non-ionic surfactants Triton X 100 (TX 100), Tween 20, Tween 40 and Tween 60.
Abstract: The visible spectra of safranine T in micellar solutions indicate 1:1 (dye to micelle) charge transfer complex formation with the non-ionic surfactants Triton X 100 (TX 100), Tween 20, Tween 40, Tween 60 and Tween 80 as well as with the anionic surfactant sodium dodecyl sulphate (SDS). The non-ionic surfactant micelles show stronger interaction than the ionic micelle SDS, the complexing strengths of the non-ionic micelles following the order Tween 80>Tween 60>TX 100>Tween 40>Tween 20. The fluorescence spectrum of the dye is also affected (intensified) by the surfactant micelles. The results confirm a 1:1 complex and comparable complexing strengths (except the position of TX 100) as revealed by the ground state spectra. Thermodynamic analysis shows that the increased stability of the dye—micelle complex is associated with a systematic increase in exothermic enthalpy and decrease in entropy which compensate each other. The equilibrium constants of the dye—micelle complex are directly proportional to the carbon numbers of the Tweens and inversely proportional to the critical micelle concentration (CMC) of the surfactants.
52 citations
TL;DR: The Dhandraul Sandstone Formation of the Middle Proterozoic Kaimur Group, the Vindhyan Supergroup, Son Valley, India, has been reinterpreted to represent a product of braided ephemeral fluvial environment as discussed by the authors.
50 citations
TL;DR: In this paper, the authors show that the shape of the early folds of a thin multilayer embedded in an incompetent host may affect the shape and geometry of the superposed buckling in multilayers.
TL;DR: In this paper, the capacitive-resistive field distribution around a post-type insulator for different severities of surface pollution is calculated by a charge simulation method and the field calculations are carried out for power frequency voltage and also for lightning and switching impulse voltages.
Abstract: HV outdoor insulators are always subjected to pollution of different nature and severity and the performance of a HV insulator under polluted conditions is quite different from that under pollution-free conditions. The present paper is concerned with the field distribution around a post-type insulator for different severities of surface pollution. The capacitive-resistive field distribution around the polluted insulator is calculated by a charge simulation method. The field calculations are carried out for power frequency voltage and also for lightning and switching impulse voltages. The effects of uniform or partial surface pollution and the presence of dry bands on the field distribution around a polluted post insulator are presented and discussed in detail. >
TL;DR: Study presented here reveal significant antiinflammatory activity of the fraction on Arachidonic acid, Platelet activation factor and Compound 48/80-induced paw oedema and significant protective action of the same on gastric mucosa.
01 Nov 1993
TL;DR: From the percolation data, the diameter of the microdispersed water droplets, their population, and surface area have been estimated, and the enthalpy of dispersion of water in AOT/oil medium has been determined from isothermal titration calorimetric measurements.
Abstract: Both volume- and temperature-induced percolation of conductance of w/o microemulsions formed with AOT in cyclic aliphatic and aromatic oils (cyclohexane, cyclohexanone, toluene, and xylenes), and volume percolation of water/AOT/oil systems using linear aliphatic hydrocarbons (n-hexane, n-heptane, n-octane, i-octane, and n-decane) have been studied. The effect of additives, viz. sodium cholate (NaC), sodium deoxycholate (NaDC), cholesterol, n-butanol, and t-butanol, toluene, and xylenes (o, m, and p) on the temperature-induced percolating processes using the oils cyclohexane and cyclohexanone has been examined. The percolation results have been analyzed in the light of scaling equation, and the energy of activation of the ion-transport phenomenon has been evaluated for both pre- and postpercolation stages. From the percolation data, the diameter of the microdispersed water droplets, their population, and surface area have been estimated. The enthalpy of dispersion of water in AOT/oil medium has been determined from isothermal titration calorimetric (ITC) measurements.
TL;DR: In this article, the components of the Einstein tensor and other relations for a spherically symmetric metric in null coordinates in higher dimensions are given for a perfect fluid with heat flow but without viscosity.
Abstract: The components of the Einstein tensor and other relations are given for a spherically symmetric metric in null coordinates in higher dimensions. These relations are particularly relevant to the study of gravitational collapse of a perfect fluid with heat flow but without viscosity, where the exterior space cannot be considered as vacuum and matching to Schwarzschild space-time is not suitable. The analysis generalizes to higher dimensions work of Cahill and McVittie in 4D space-time. Using the expression for the “mass function,” it is observed that pressure vanishes at the boundary of the distribution for a perfect fluid in the higher-dimensional case also, but the same is not true when heat flow is considered.
TL;DR: Methdilazine could inhibit various Mycobacterium spp.
Abstract: Methdilazine (Md) could inhibit various Mycobacterium spp. at 5-15 micrograms/ml concentrations in vitro as well as in vivo. When Md was tested in combination with streptomycin (Sm), rifampicin (Rf) or methyl-DOPA (m-D), it showed synergistic effects only with respect to methyl-DOPA.
TL;DR: The prospect of such a heavy right-handed neutrino search via [ital W][sub [ital R]] decay in the like-sign dilepton channel at the Superconducting Super Collider (SSC) and CERN Large Hadron Collider (LHC) is explored.
Abstract: Right-handed neutrinos with a large Majorana mass occur naturally in the left-right-symmetric model. We explore the prospect of such a heavy right-handed neutrino search via [ital W][sub [ital R]] decay in the like-sign dilepton channel at the Superconducting Super Collider (SSC) and CERN Large Hadron Collider (LHC). The standard model background can be effectively eliminated by suitable lepton [ital p][sub [ital T]] and isolation cuts without affecting the signal cross section seriously. In this way it seems possible to explore the bulk of the parameter space 0[lt][ital M][sub [ital N][ital R]][lt][ital M][sub [ital W][ital R]], with [ital M][sub [ital W][ital R]] going up to 3000 (2000) GeV at energies reached at the SSC (LHC).
TL;DR: A stochastic reliability model for the haploid, binary, fixed-length genetic algorithm is presented and empirical evidence is provided.
TL;DR: There are successive generations of mafic and ultramafic dykes within the gneissic rocks of the Schirmacher Hills in East Antarctica, and three major groups of events can be recognized by comparison of their internal structures with those of their charnockitic or granitic host, and by identification of their successive stages of transformation by metamorphism and migmatization.
TL;DR: In this article, the mechanism of tellurium separation from selenium in hydrochloric acid media by solvent extraction with tri-n butyl phosphate in kerosene was investigated in a batch-stirred glass cell.
Abstract: We present the detailed results of our palaeointensity experiments on mid-Cretaceous basaltic lavas from the Rajmahal Traps in northeastern India and several formations in Israel. The aim of this study was to provide the first estimates of the geomagnetic field strength during the long period of normal polarity, the Cretaceous Quiet Zone. Using rock magnetic techniques-strong-field thermomagnetic behaviour, low-field low temperature susceptibility variation, and hysteresis properties, supported by optical and electron microscopy we have determined the magnetic mineralogy of the 48 sample sites. Deuteric oxidation is largely absent in both Israeli and Indian lavas, resulting in low Curie temperatures. Some degree of low temperature oxidation is always found in the Indian lavas, but is not common in the Israeli rocks. Stepwise thermal and alternating field demagnetisation show that many Israeli rocks have strong very soft overprints which may be lightning strikes. Although Cretaceous field directions are recorded in both Israeli and Indian lavas, and indicate that most of the lavas erupted during a period of normal polarity, the quality of the palaeomagnetic data is much higher in the Indian lavas with lower within site scatter. For each site, two samples were measured using the modified Thellier palaeointensity technique, and two using the Shaw technique with Rolph-Shaw correction. The magnetic mineralogy of the rocks are not conducive to obtaining good quality palaeointensity data. The within site scatter was often very high, particularly in the case of the Israeli lavas, where the Thellier technique often failed because secondary components could not be removed and the Shaw method failed because the rocks demagnetised completely at low alternating fields. This has led to one or two of the palaeointensity results being rejected from most sites, and a few Israeli sites being rejected altogether. The mean virtual dipole moment (VDM) from the Israeli lavas is 4.7 ± 2.2 (1 SD) × 1022 Am2 (from 20 out of 25 sites), and for the Rajmahal Traps 5.5 ± 1.9 × 1022 Am2 (from 23 out of 23 sites). Both mean VDMs are lower than our previously published preliminary estimates based only on Thellier data. From radiometric ages it would appear that the igneous activity in the Ramon and the Rajmahal areas is almost contemporaneous; hence the mean VDMs from these two formations should give a similar estimate of the mean dipole moment of the Earth at the beginning of the Cretaceous Quiet Zone. Combining the intensity data from these two areas, the estimated mean VDM for this time is 5.4 ± 1.9 × 1022 Am2 (n = 37). From this it appears that the Mesozoic dipole low had ended before the onset of the Cretaceous Quiet Zone.
TL;DR: In this article, the problem of two-dimensional steady-state heat flow in the stator of an induction motor is solved using finite element formulation and using arch shaped elements in the theta plane of the cylindrical coordinate system.
Abstract: The problem of two-dimensional steady-state heat flow in the stator of an induction motor is solved using finite element formulation and using arch shaped elements in the theta plane of the cylindrical coordinate system. The shape functions and exact solution matrices are derived algebraically for utmost economy in computation. The temperature distribution has been determined considering convection from the stator frame and the cylindrical air-gap surface. The temperatures obtained by this two-dimensional approximation are compared with the actual temperatures obtained by three-dimensional analysis. >
TL;DR: In this article, three types of mineral associations are described from calc-silicate granulites from the Eastern Ghats, India, where geothermobarometry in associated rocks suggests extremely high P-T conditions of metamorphism (c. 9 ± 1 kbar, 950° C).
Abstract: Three types of mineral associations are described from calc-silicate granulites from the Eastern Ghats, India, where geothermobarometry in associated rocks suggests extremely high P-T conditions of metamorphism (c. 9 ± 1 kbar, 950° C). These mineral associations are: (i) calcite + quartz + scapolite + plagioclase, (ii) calcite + scapolite + wollastonite + porphyroblastic garnet + coronal garnet and (iii) calcite + quartz + wollastonite + scapolite + porphyroblastic garnet + coronal garnet, all coexisting with K-feldspar, titanite and clinopyroxene. The first two associations evolved through nearly isobaric cooling retrograde paths, whereas the third evolved through a nearly isothermal decompression path followed by an isobaric cooling retrograde path. Textural and compositional characteristics suggest the following mineral reactions in the calc-silicate granulites: calcite + quartz = wollastonite + CO 2 , calcite + plagioclase = scapolite, calcite + scapolite + wollastonite = porphyroblastic garnet ± quartz + CO 2 , CaTs + wollastonite = coronal garnet (association ii) and wollastonite + scapolite = coronal garnet (association iii) + quartz + CO 2 . Andradite content in garnet was buffered by the redox equilibria wollastonite + hedenbergite + O 2 = andradite + quartz (association iii) and wollastonite + andradite + CaTs + scapolite = hedenbergite + calcite + grossular + O 2 (association ii). The contrasting mineral parageneses have been ascribed to interplay of variables such as X CO2 , f O2 , f HCl in the fluid, bulk Na content and the nature of the retrograde P-T-X CO2 paths through which the rocks evolved.
TL;DR: Along the coast of East and South India, a slow and minor sea level fall as an immediate response to the Last Glacial Maximum (LGM) followed by strong aridity and fast retreat of the sea to the outer shelf are indicated by coastal ironstones, traces of channels in nearshore shallow seismic reflectors, and submerged, structureless, multimineral placer sands as discussed by the authors.
Abstract: Along the coast of East and South India, a slow and minor sea level fall as an immediate response to the Last Glacial Maximum (LGM) followed by strong aridity and fast retreat of the sea to the outer shelf are indicated by coastal ironstones, traces of channels in nearshore shallow seismic reflectors, and submerged, structureless, multimineral placer sands. Nearshore peat beds and inland beach ridges reflect perturbations during Early to Mid-Holocene sea level rise. The Little Ice Age witnessed shifts in littoral sediment budget, possibly as a result of reduced transport of sediments from the Himalaya to the Bay of Bengal.
TL;DR: The study revealed a dynamic aspect of modulation of the peritoneal cells by SJ‐P (200–600 mcg/mouse), when administered intraperitoneally, and suggested that by carefully determining the dose, SJ-P can be used in wound healing and in related inflammatory disease states.
Abstract: The effect of processed shilajit (SJ-P) was evaluated on murine peritoneal macrophages and on the cohabiting fibroblasts. The study revealed a dynamic aspect of modulation of the peritoneal cells by SJ-P (200–600 mcg/mouse), when administered intraperitoneally. The findings further suggested that by carefully determining the dose, SJ-P can be used in wound healing and in related inflammatory disease states.
TL;DR: In this paper, the authors studied the thermoelectric power of the electrons under magnetic quantization in III-V, II-VI, PbTe/PbSnTe and strained layer superlattices with graded interfaces and compared the same with the corresponding bulk specimens of the constituent materials.
Abstract: We study the thermoelectric power of the electrons under magnetic quantization in III–V, II–VI, PbTe/PbSnTe and strained layer superlattices with graded interfaces and compare the same with the corresponding bulk specimens of the constituent materials by formulating the respective expressions incorporating the broadening. It is found, by taking GaAs/Ga1−x Al x As, CdS/CdTe, PbTe/PbSnTe and InAs/GaSb superlattices with graded interfaces as examples, that the thermoelectric power exhibits oscillatory dependence with the inverse quantizing magnetic field due to Shubnikov-de Hass effect and increases with decreasing electron concentration in an oscillatory manner in all the aforementioned cases. The thermopower in graded superlattices is greater than that of constituent bulk materials together with the fact that the oscillations in superlattices show up much more significantly as compared to the respective constituent materials. In addition, the well-known expressions for bulk specimens of wide-gap semiconductors have also been obtained as special cases from our generalized expressions under certain limiting conditions.
TL;DR: In this paper, a comprehensive study on a phase change material (PCM) storage system and development of a mathematical model have been attempted in order to describe the melting characteristics of paraffin wax encapsulated in the annulus of two concentric cylinders.
TL;DR: Application of ozone on AFB1‐contaminated foodcrops seems to be a promising preventive measure against any adverse immunological disorder in consumers.
Abstract: The impact of ozone on the immunity-impairing activity of aflatoxin B 1 (AFB 1 ) was studied. Phagocytosis by rat peritoneal macrophages, which was found to be suppressed in the presence of AFB 1 , remained unimpaired when the applied AFB 1 was pretreated with ozone (1.2 mg 1 −1 ) for 6 min at a flow rate of 40 ml min −1 . Hence, application of ozone on AFB 1 -contaminated foodcrops seems to be a promising preventive measure against any adverse immunological disorder in consumers
TL;DR: A corundum-bearing, spinel-sapphirine-garnet-sillimanite-quartz-(Fe-Ti)-oxide granulite from the Eastern Ghats belt, India, shows reaction textures that suggest formation of coronitic garnet and sillimanite around spinel, quartz and sapphirines as mentioned in this paper.
Abstract: A corundum-bearing, spinel-sapphirine-garnet-sillimanite-quartz-(Fe-Ti)-oxide granulite from the Eastern Ghats belt, India, shows reaction textures that suggest formation of coronitic garnet and sillimanite around spinel, quartz and sapphirine. Mineral-chemical data, chemographic analysis and consideration of the relevant petrogenetic grid in the system FMAS indicate that the mineral reactions occurred in response to nearly isobaric cooling after the metamorphic peak.
TL;DR: The methanol fraction of the extract of Pluchea indica roots exhibited significant hepatoprotective activity against experimentally induced hepatotoxicity by carbon tetrachloride in rats and mice, suggestive of a potent hepatoprotsective effect of the Extract under investigation.
Abstract: The methanol fraction of the extract of Pluchea indica roots exhibited significant hepatoprotective activity against experimentally induced hepatotoxicity by carbon tetrachloride in rats and mice. The extract caused significant reduction of the elevated serum enzyme levels (AST, ALT, LDH and serum alkaline phosphatase) and serum bilirubin content in acute liver injury. A significant increase of reduced serum total protein, albumin and albumin/globulin ratio was also observed on extract treatment. The extract significantly reduced the prolonged pentobarbitone-induced sleeping time and also caused a significant reduction of plasma prothrombin time in comparison with CCl4-treated animals. The extract caused significant reduction of the increased bromosulphalein retention by CCl4-treatment. These findings are suggestive of a potent hepatoprotective effect of the extract under investigation.