Showing papers by "Jadavpur University published in 1997"
TL;DR: In the past twenty five years, micro-emulsions have been the focus of extensive research worldwide due to their importance in a variety of technological applications as mentioned in this paper, such as enhanced oil recovery, combustion, cosmetics, pharmaceuticals, agriculture, metal cutting, lubrication, food, enzymatic catalysis, organic and bio-organic reactions, chemical synthesis of nanoparticles etc.
Abstract: In the past twenty five years, microemulsions have been the focus of extensive research worldwide due to their importance in a variety of technological applications. These applications include enhanced oil recovery, combustion, cosmetics, pharmaceuticals, agriculture, metal cutting, lubrication, food, enzymatic catalysis, organic and bio-organic reactions, chemical synthesis of nanoparticles etc. The basic purpose of this review is intended to provide the most important features of microemulsions and their applications. Emphasis is placed on recent works, however, the reference list is by no means complete. In order to limit the size of the review, a more or less arbitary selection has been made with respect to examples chosen from literature. The review is started with a brief introduction and focussed with definition, structure, type, formation characteristics, stability, phase behavior and the effect of additives, pressure, temperature on the phase behavior of microemulsion. In addition, the p...
322 citations
TL;DR: In this article, the second-order elastic constants (SOEC's), their pressure derivatives, and the third-order linear constants (TOEC's) were evaluated from Girifalco potential function.
Abstract: Considering that Coulomb interactions contribute a negligible amount to the cohesive energy in ${\mathrm{C}}_{60}$, which has an fcc structure at room temperature, we used Girifalco potential function in our calculations; ${\mathrm{C}}_{60}$ is spherical in nature and rotates rather freely at room temperature. From this potential we evaluated the second-order elastic constants (SOEC's), their pressure derivatives, and the third-order elastic constants (TOEC's). The SOEC's are found to be in good agreement with other literature values reported so far. The pressure derivative of bulk modulus is found to be 3.8 which compares favorably with Duclos values while the theoretical literature value is reported to be high. The pressure derivatives of the SOEC's are found to be high compared with those of glassy, amorphous materials, alloys, and metals. Furthermore, the derivatives are all found to be positive. The TOEC's are all found to be negative resembling those of polymers like polystyrene. We evaluated the thermal Gruneisen's constant from the potential function and the value obtained is in excellent agreement with experiment.
225 citations
TL;DR: In this paper, a finite time-horizon deterministic economic order quantity (EOQ) inventory model with shortages was developed, where the demand rate at any instant depends on the on-hand inventory (stock level) at that instant.
193 citations
Journal Article•
TL;DR: Processed extract suppressed significantly the tumor fluid volume and increased life span of EAC/S-180 bearing mice in a day dependent manner and inhibited the rapid increase of body weight of tumor bearing mice.
Abstract: Petroleum ether extract from H. spinosa root exhibited antitumor activity in Ehrlich ascites carcinoma and Sarcoma-180 bearing mice Processed extract suppressed significantly the tumor fluid volume at the end of 3 weeks experiment. It decreased about 50% of packed cell volume and increased life span of EAC/S-180 bearing mice in a day dependent manner. Red blood cell count, hemoglobin content and white blood cell count were more or less normal after processed extract treatment of the tumor bearing mice. In tumor control animals, neutrophils increased (273.7% in EAC and 263.4% in S-180 bearing mice respectively with respect to normal mice) whereas lymphocytes decreased (60.0% in EAC and 56.5% in S-180 bearing mice respectively with respect to normal mice). It also inhibited the rapid increase of body weight of tumor bearing mice.
138 citations
TL;DR: Oral administration of the ethanolic extract of rhizomes of Nelumbo nucifera markedly reduced the blood sugar level of normal, glucose-fed hyperglycemic and streptozotocin-induced diabetic rats, when compared with control animals.
134 citations
TL;DR: In this article, the authors considered the inventory replenishment problem over a finite time horizon for a deteriorating item with a linear trend in demand, equal replenishment cycles and shortage in every cycle.
119 citations
TL;DR: In this paper, it was shown that the Brans-Dicke theory of gravity does not always go over to general relativity in the ∆-approximation limit.
Abstract: In this work it is shown that the Brans-Dicke theory of gravity does not always go over to general relativity in the $\ensuremath{\omega}\ensuremath{\rightarrow}\ensuremath{\alpha}$ limit. It is also shown, by an order of magnitude estimate, that one can get general relativity as a limit of Brans-Dicke theory when $\ensuremath{\omega}\ensuremath{\rightarrow}\ensuremath{\alpha},$ only if the trace of the energy-momentum tensor describing all fields other than the Brans-Dicke scalar field is nonzero.
118 citations
105 citations
TL;DR: The results were comparable to those of a standard drug, nitrofurazone, in terms of wound contracting ability, wound closure time, tensile strength and regeneration of tissues at the wound site.
101 citations
TL;DR: In this article, three complexes of the formula [Zn(2,2′-biny)(CCl3CO2)2(H2O)]n have been synthesized and characterized by elemental analysis, IR spectra, thermal analysis and single-crystal X-ray diffraction for 1 and 2.
78 citations
TL;DR: In this article, the authors presented a theory of interest rate determination on informal credit in backward agriculture when there is a market for formal credit and the farmer has to bribe the official of the formal credit agency in order to get formal credit.
Abstract: The paper presents a theory of interest rate determination on informal credit in backward agriculture when there is a market for formal credit. The farmer has to bribe the official of the formal credit agency in order to get formal credit. The official and the moneylender play a non-cooperative game in choosing the amount of formal credit and the informal interest rate, respectively. The informal-sector interest rate and the effective formal-sector interest rate (incorporating the bribe) are equal in equilibrium. A reduction in the formal interest rate and/or an increase in the price of the product may lead to an increase in the equilibrium bribing rate and the informal interest rate when the formal credit and the informal credit are complementary to each other.
TL;DR: In this article, the solution and interfacial behaviours of binary mixtures of tert-octylphenylpolyoxyethyleneether (Triton X-100 or TX-100) and polyoxyethylenesorbitanmonooleate (Tween-80 or TW-80) and ternary mixtures were studied in details using conductometric, spectrophotometric, fluorimetric and tensiometric techniques.
TL;DR: In this article, a branch exchange algorithm based on the branch exchange technique is proposed for the planning of radial distribution systems, which is not based on node and branch numbering schemes and therefore is particularly suitable for planning environment.
Abstract: This paper reports the development of a new algorithm for the planning of radial distribution systems. The algorithm is based on the branch exchange technique. Branch exchange has been applied in two stages-between the elements of the network under each substation, called intrazone branch exchange and between the elements of the networks under adjacent substations, called interzone branch exchange. Intrazone exchange determines the optimum network configuration of each substation and interzone exchange determines the optimum service area of each substation. A complete power flow is required after each successful branch exchange. A new algorithm has also been proposed for the load flow of radial distribution networks. The algorithm is not based on node and branch numbering schemes and can handle multiple number of zones and therefore is particularly suitable for planning environment.
TL;DR: In this article, the total energy of the universe has been calculated assuming that it is the sum of the contributions from the matter part and the gravitational part, using the use of the Einstein pseudotensor.
Abstract: The total energy of the universe has been calculated assuming that it is the sum of the contributions from the matter part and gravitational part. The calculations involve the use of Einstein pseudotensor. Calculations have been carried out in some specific examples of spacetime geometries. In some cases the total energy is indeed zero confirming previous results but in other cases the total energy is nonzero. So Rosen’s idea that the pseudotensorial calculations will lead to the result that the total energy of the universe is zero, is very much model dependent.
TL;DR: In this article, a finite element method was used to solve conjugate conduction with natural convection in a square enclosure, where the set of governing equations have been reframed and put into a form that can easily fit into the Galerkin formulation.
TL;DR: The 2.3 Ga fine-grained siliciclastic Chaibasa Formation of eastern India locally retains an excellent record of sandwave migration under the influence of tides and storms within a precursor sandstone facies in a largely subtidal setting and provides a rare opportunity to detect tidal periodicities.
TL;DR: In this paper, a detailed study of a 27-km strike-parallel stretch between Chorhat and Shikarganj against a broader perspective reveals existence of multiple NW-SE-elongated subbasins.
TL;DR: In this article, a three-sector static model of a small open economy with special consideration to the urban informal sector and the informal capital market is developed with the special consideration of the capital market.
TL;DR: In this article, the authors have developed activated carbon pellets from coconut shell and also designed a PSA adsorption system for studying the effectiveness of the activated carbon pellet in separating carbon dioxide.
TL;DR: The first model of Chandra and Khan (1993) has been extended in the following directions: (1) migration equilibrium condition has been generalized; (2) capital market distortion has been introduced; (3) land as an agricultural input has been considered.
Abstract: The first model of Chandra and Khan (1993) has been extended in the following directions: (1) migration equilibrium condition has been generalized; (2) capital market distortion has been introduced; (3) land as an agricultural input has been considered. It appears that the Brecher–Alejandro (1977) proposition may lose its validity in some special cases.
TL;DR: Beta-carotene ranks as a potential chemopreventive agent for the future so far as chemical rat liver carcinogenesis is concerned by monitoring its effect on rat liver chromosomal aberrations and DNA chain breaks during the early preneoplastic stage of diethylnitrosamine (DEN)-induced hepatocarcinogenesis in male rats.
Abstract: Beta-carotene (BC) has recently been found to possess potent anti-tumour activity in chemically induced rat liver carcinogenesis. In the present study, attempts have been made to understand the basic cytogenetic and molecular mechanism of the anti-tumour effect of BC by monitoring its effect on rat liver chromosomal aberrations (CAs) and DNA chain breaks during the early preneoplastic stage of diethylnitrosamine (DEN)-induced hepatocarcinogenesis in male rats. DNA chain breaks, however, can be detected with great sensitivity by exposing crude cell lysates to alkaline solutions and monitoring the rate of strand unwinding so that one strand break per chromosome can easily be detected. Supplementary BC, in basal diet (120 mg kg[-1]), was given to rats 15 days before carcinogenic threat with DEN. Under these experimental conditions, BC was found to afford a unique protection against DEN-induced CAs 96 h after DEN injection. Long-term treatment with BC also triggered a protective effect on induction of CAs 15, 30 or 45 days after DEN treatment, which was maximal on structural aberrations followed by numerical and physiological types. BC treatment for 15 days before DEN injection was found to offer a significant (P < 0.001) protection in the generation of single-strand breaks compared with DEN control. Thus, BC ranks as a potential chemopreventive agent for the future so far as chemical rat liver carcinogenesis is concerned.
TL;DR: In this paper, a two-stage evolution model of the ore fluid is described, where the first stage witnessed mixing of the two components, F1 and F2 in unequal proportion, bringing about mineralization.
Abstract: Copper and subordinate molybdenum mineralization at Malanjkhand occurs within a fracture-controlled quartz-reef enclosed in a pink granitoid body surrounded by grey-granitoids constituting the regional matrix. Sulfide-bearing stringers, pegmatites with only quartz + microcline and sulfide disseminations, all within the pink-granitoid, represent other minor modes of occurrences. Despite this diversity in mode of occurrence, the mineralogy of ores is quite consistent and conform to a common paragenetic sequence comprising an early `ferrous' stage of precipitation of magnetite (I) and pyrite (I) and, the main-stage chalcopyrite mineralization with minor sphalerite, pyrite (II), magnetite (II), molybdenite and hematite. Both stages witnessed continuous precipitation of quartz ± microcline ± (chlorite, biotite and epidote). The enclosing pink-granitoid and the regional grey-granitoids display alteration features such as saussuritization of plagioclase, breakdown of hornblende and chloritization of biotite on a regional scale, indicating interaction with a pervasive fluid. Quartz and microcline precipitation mostly restricted within the pink granitoid, postdates this alteration. Four types of primary inclusions were encountered in quartz from ore samples: (1) type-I – aqueous-biphase(L + V) inclusions, the commonest variety in all ore types; (2) type-II – aqueous-carbonic(Laq + Lcarb ± Vcarb); (3) type-III – pure-carbonic(Lcarb ± Vcarb) – type-II and III being restricted to stringer and pegmatitic ores, and (4) rare polyphase (Laq + Vaq + calcite/gypsum) inclusions. Quartz in granitoids contain primary type-I inclusions only. Type-I inclusions from ore samples furnish a temperature range (after a rough pressure correction to the TH -maxima of 140–180 °C) of 150–275 °C and a moderately low salinity of 4–12 wt.% NaCl equivalent. This is inferred to represent the signature of the major component (F2) of the ore fluid. A few type-I inclusions of higher TM (up to 380 °C) and low salinity and density represent the other (F1) identifiable component of the ore fluid present in low proportion. The TH -maxima and the total range in salinity of type-I inclusions in quartz from granitoids are strikingly similar to those from the ore samples. Composition of syn-ore chlorites furnished a temperature range of 185–327 °C, which conforms to the fluid inclusion microthermometric data. Pressure estimates using standard fluid inclusion geobarometric methods, vary from 550 to 1790 bar in the stringer ores. Observed temperature-salinity/density relationships are best explained by a two-stage evolution model of the ore fluid: the first stage witnessed mixing of the two components, F1 and F2 in unequal proportion, bringing about mineralization. The second stage of evolution was marked by the separation of a carbonic component on continued sulfide precipitation and attendant increase in salinity of the fluid. The F1 component emerged as a distinct, heated and (CO2 + S)-charged entity due to steam-heating and contamination of the early-ingressed F2 fluid at the fracture zone. The pervasive fluid phase in the surrounding granitoids contributed the F2 component.
TL;DR: In this article, it was shown that pelitic rocks were thermally metamorphosed at the contact of the Chimakurthy mafic-ultramafic igneous complex, Eastern Ghats Belt, India.
Abstract: Pelitic rocks were thermally metamorphosed at the contact of the Chimakurthy mafic-ultramafic igneous complex, Eastern Ghats Belt, India. The rocks show progressive change in mineralogy from biotite-sillimanite-quartz-garnet-K-feldspar (association I, 150 m from the intrusive contact) to garnet-spinel-cordierite-K-feldspar-sillimanite (association II, 20–30 m from the intrusive contact) to cordierite-K-feldspar-(cordierite-orthopyroxene-K-feldspar symplectite after osumilite)-spinel-FeTiAl oxides with/without garnet (associations III and IV, 5 m from the intrusive contact), and finally to spinel-orthopyroxene-cordierite-K-feldspar (association V, xenoliths). Oxide mineral clots in associations III and IV resemble emery-type rocks. Initial mineral reactions involved biotite-dehydration melting with partial segregation of the melt. Down-temperature mineral reactions were largely diffusion controlled and preservation of symplectitic and coronitic textures in microdomains is common. Interpretation of reaction textures in relevant petrogenetic grids for the sytems KFMASH and FMAS and combined with geothermobarometry suggest that the pelitic rocks were thermally metamorphosed at c. 6 kbar pressure along a heating-cooling trajectory within the temperature interval between c. 750 °C and c. 1000 °C.
TL;DR: In this paper, the surface charge of the micellar aggregates was found to be affected by the surface charges of the DMABN in the photo-excited state, and a comparative study of the enhancement of the TICT and the locally excited (LE) or non-polar (NP) emission yields in the two mousellar solutions was performed.
01 Jan 1997
TL;DR: In this article, the authors evaluate the relationship of imbricate thrust spacing with the bed thickness (H), basal friction (μb), initial taper (mw), and the magnitude (normalized to bed-weight per unit area) of horizontal stress (n).
Abstract: With the help of model experiments and theoretical analyses we evaluate the relationships of imbricate thrust spacing (a) with the bed thickness (H), basal friction (μb), initial taper (mw), and the magnitude (normalized to bed-weight per unit area) of horizontal stress (n). Imbricate thrust spacing increases linearly with bed thickness when mw = 0 and initial-stage thrust imbricates are taken into account. For general cases (mw≠0) the variations are nonlinear. In nonlinear variations thrust spacing steadily increases but approaches a stable value. The variations for large mw are complex, where thrust spacing increases to a maximum and then decreases down to a near-stable value. Thrust spacing shows a positive relationship with the dynamic factor, n. With increase in basal friction, thrust spacing decreases. Steepening of early frontal thrusts and formation of back-thrust also depend on the basal friction.
TL;DR: In this article, a thorough study and application of flow injection atomic absorption spectrometry for the determination of As, Pb and Hg in parts per million to sub-parts per billion levels in environmental and biological samples have been described.
Abstract: Results of a thorough study and application of flow injection atomic absorption spectrometry for the determination of As, Pb and Hg in parts per million to sub-parts per billion levels in environmental and biological samples have been described. Various standard reference materials from the National Bureau of Standards, USA, the National Institute of Standards and Technology, USA, the Community Bureau of Reference, Brussels, Belgium and the National Institute for Environmental Studies, Japan and Standard Chinese river sediment were used. By flow injection hydride generation AAS the standard reference materials were analyzed for As and Pb. Mercury was determined by cold vapour flow injection AAS from environmental and biological standard reference materials. The technique is fast, simple and highly sensitive. It takes only 30 s for each analysis from the digested solution. The detection limits of As, Pb and Hg are 1.8 μg L–1 and 2.0 μg L–1 and 1.5 μg L–1, respectively. The results show good agreement with the certified values.
TL;DR: The extent of adsorption of CTAB, myristyltrimethylammonium bromide (MTAB), and DTAB from aqueous solution onto a cellulose substrate was investigated in this article.
Abstract: The extent of adsorption (Γ21) of cetyltrimethylammonium bromide (CTAB), myristyltrimethylammonium bromide (MTAB), and dodecyltrimethylammonium bromide (DTAB) from aqueous solution onto a cellulose...
TL;DR: The measured heat capacities of all the systems agree very reasonably with the calculated values assuming ideal mixing behavior of the components, and the surfactant concentration at the inversion point bears a linear correlation with the concentration of the dispersed solvent.
09 Sep 1997
TL;DR: The present paper extends the branching process model proposed by Chakraborty (1995) to cover linear ranking selection and binary tournament selection in genetic algorithms.
Abstract: The present paper extends the branching process model proposed by Chakraborty (1995) to cover linear ranking selection and binary tournament selection in genetic algorithms. Simulation results are presented.
TL;DR: In this paper, the visible and fluorescence spectra of the dye safranine T were studied in micellar solutions of non-ionic surfactants in different concentration ranges.
Abstract: The visible and fluorescence spectra of the dye safranine T were studied in micellar solutions of non-ionic surfactants in different concentration ranges. The complexing strengths (1 : 1 dye : micelle charge transfer complex formed between the dye and micelle) of the non-ionic micelles increase with increasing concentration of the surfactant in the micellar solution. The aggregation number and several solvent parameterss, i.e. the Kosower z value, intramolecular charge transfer energy E T 30 , dielectric constant of the micellar medium and viscosity of the micellar solution, were evaluated. These values remain constant over certain concentration ranges, but vary in different concentration regions of a surfactant.