Showing papers by "Banaras Hindu University published in 1983"
TL;DR: In this article, the effect of a uniform transverse magnetic field on the free convection flow of an electrically conducting fluid past an infinite vertical plate for both the classes of impulsive as well as uniformly accelerated motion of the plate is discussed.
121 citations
TL;DR: In this paper, an attempt was made to burn hydrogen in compression ignition engines that were operated on a dual fuel principle, where hydrogen was supplied along with intake air in small proportions and ignition was initiated by injecting diesel fuel in the conventional manner.
105 citations
TL;DR: The physical conditions of metamorphism have been evaluated by applying methods of geothermobarometry to the widespread charnockitic assemblages with garnet, orthopyroxene, clinopyroxenes, plagioclase, and quartz as discussed by the authors.
Abstract: In the southern part of the Archaean craton of South India, an approximately 3.4–2.9 b.y. old migmatite–gneiss terrane (Peninsular gneiss complex) has been subjected to granulite facies metamorphism about 2.6 b.y. ago. During this event, the extensive charnockite-khondalite zone of southern India developed. A younger metamorphism (Proterozoic?) led to retrogression of the charnockites and khondalites, mainly under the conditions of the amphibolite facies.The physical conditions of metamorphism have been evaluated by applying methods of geothermobarometry to the widespread charnockitic assemblages with garnet, orthopyroxene, clinopyroxene, plagioclase, and quartz. The interpretation of the P–T estimates includes a critical discussion of potential error sources, e.g. errors of the analytical data and the calibrations of the models, and takes into account the complex metamorphic history of the rocks and the kinetics of the mineral equilibria.P-T estimates were obtained for seven subareas from the rim compositions of the coexisting minerals: Shevaroy Hills 680±55°C—7·4±1 kb; Kollaimalai area 680±40°C—8·6± 1 kb; Nilgiri Hills 680±90°C—6·6±0.8kb (upland massif) and 705±60°C—9·3±0.8 kb (northern margin); Bhavani Sagar area 650±50°C—7·2± 1 kb; Sargur-Mysore area 690±60°C—7·6 kb; Bangalore-Kunigal-Satnur area 760±50°C—6 kb. Except for the last subarea, the P-T model data reflect the conditions of a late annealing stage probably related to the retrogressive metamorphism. Conditions near the peak of granulite facies metamorphism (730–800°C—6·5–9·5 kb) are recorded by the core compositions of the minerals. Although a rather uniform cooling history of the main part of the charnockite-khondalite terrane is suggested from the temperature data, differential uplift of smaller blocks is indicated by the regional variation of the pressure data.
98 citations
TL;DR: The main results are the following: the frequencies of all types of chromosome aberrations at 0.4 rad are significantly lower than the control values, and over the entire dose range the dose-effect relationship is clearly non-linear.
Abstract: In a coordinated research programme sponsored by the Internation Atomic Energy Agency, the frequencies of chromocomal aberrations induced in peripheral blood lymphocytes (in vitro) by 250 kV X-rays at low doses (04, 1, 2, 3, 5, 10 and 30 rad) were determined Blood from 2 donors was used to conduct one master experiment at these dose levels The culture time used was 48 h and all samples including the controls were processed according to a standard protocol The coded slides were scored by investigators from 10 participating laboratories The main results are the following: (1) the frequencies of all types of chromosome aberrations at 04 rad are significantly lower than the control values; (2) there is no increase in the frequencies of dicentrics up to 2 rad and in those of terminal deletions up to 5 rad; (3) the mean frequencies of all aberrations considered together are not significantly different from one another at 1,2 and 3 rad ( P = 005); and (4) over the entire dose range the dose-effect relationship is clearly non-linear A fit of these data to a linear quadratic model ( E ( D ) = c + αD + βD 2 ) showed that the observed total aberration frequencies at doses 1,2,3 and 5 rad are below the curve defined by the model The deviations can be explained by an altered kinetics of aberration production at very low doses probably due to DNA repair mechanisms operating in these cells
96 citations
TL;DR: In this article, a generalization of Einstein's theory is discussed in which the gravitation is described by a tensor and a scalar field, which is more consistent with Mach's principle and less reliant on absolute properties of space.
Abstract: A generalization of Einstein's theory is discussed in which the gravitation is described by a tensor and a scalar field. The theory is more consistent with Mach's principle and less reliant on absolute properties of space. The modification involves a violation of the “strong principle of equivalence” on which Einstein's theory is based. In the original version of this new theory, the “constant” of gravitationG is varying and particle masses are fixed. Later on another version of the theory was given in whichG is truly a constant and the particle masses vary. The two versions are related by a conformal transformation. The physical and mathematical foundations of this theory have been discussed and the field equations have been derived. The astrophysical and cosmological consequences of the theory have been elaborately reviewed.
94 citations
TL;DR: Two new pyrrolophenanthridone alkaloids, pratorimine and pratosine, have been isolated and characterized from the bulbs of Crinum latifolium on the basis of comprehensive spectral analyses, chemical transformation and synthesis.
65 citations
TL;DR: In this article, a discussion of connaissances sur l'origine et la croissance de structures polytypes is presented, together with les autres explications possibles for le polytypisme.
50 citations
TL;DR: In this paper, mass transfer effect on the free-convection flow of an incompressible viscous fluid past a uniformly accelerated infinite vertical plate is discussed when there is a constant heat flux between fluid and plate.
Abstract: In the present paper, mass transfer effect on the free-convection flow of an incompressible viscous fluid past a uniformly accelerated infinite vertical plate is discussed when there is a constant heat flux between fluid and plate. The expressions for the velocity field and the skin-friction have been obtained by the Laplace-transform technique. The influence of the various parameters entering into the problem is extensively discussed with the help of graphs and table.
43 citations
TL;DR: In this article, a Bayes estimator was proposed, which is a shrinkage estimator and has smaller MSE than the estimator (sample mean) n/(n + 1) if sample size, n, is small and other restrictions apply.
Abstract: This paper shows some simple shrunken estimators for the scale parameter of an exponential distribution and compares them with minimum MSE estimator and the estimator proposed by Pandey We have also obtained a Bayes estimator, which is a shrinkage estimator and has smaller MSE than the estimator (sample mean) n/(n + 1) if sample size, n, is small and other restrictions apply.
36 citations
TL;DR: A lack of detailed facies studies has resulted in a false impression of the Mesozoic depositional setting in Kachchh, western India (previously known as Kutch or Cutch) as mentioned in this paper.
Abstract: A lack of detailed facies studies has resulted in a false impression of the Mesozoic depositional setting in Kachchh, western India (previously, Kachchh has been termed ‘Kutch’ or ‘Cutch’). In addition, designation of part of this sequence as Gondawana implies, by tradition, a predominantly non-marine origin. Recently, we examined these Jurassic–Cretaceous units and found numerous wave-built sedimentary structures that have been previously overlooked or unreported, abundant marine trace fossils, and highly bioturbated and glauconite-rich beds. Thus, we now propose a marine origin for the entire Kachchh succession. This interpretation has important implications regarding similar sequences around the Indian plate margin.
35 citations
TL;DR: In this article, the authors compared the electron transport and magnetic properties of LaCoO 3 and La 1− x Sr x CoO 3 with the absence of an itinerant band of Co 4+ whose generation is restricted on account of substitution of Ti 4+.
TL;DR: The present investigation examines various karyotypic changes which have accompanied the evolutionary differentiation of the three species, and describes the Gand C-band patterns of their chromosomes, to determine the degree of karyotypesic homology and distribution of constitutive heterochromatin.
Abstract: Comparative karyotype analysis of M. musculus and its allied Indian pygmy mice species from their proposed region of origin, India (Misonne, 1969), is expected to reflect the naturally occurring cytogenetic steps through which these species have evolved. Mus booduga and Mus dunni, commonly known Indian pygmy mice, are morphologically extremely similar, inhabit the same fields, and until quite recently were considered conspecific. Mus musculus is a commensal form, closely allied to the pygmy mice, and is distinguishable only on the basis of average characters (Ellerman, 1961). The prevalent diploid number in all three species is 40, and, while M. musculus and M. booduga always display fixed karyotypes of all acrocentric chromosomes, the M. dunni karyotype, distinguishable on the basis of its large sex chromosomes, has been reported to be polymorphic from different localities in India (Matthey and Petter, 1968; Markvong et. al., 1975; Sharma and Garg, 1975). This polymorphism involves variation in the number and distribution of perceptible short arms on the autosomes of this species. The present investigation examines various karyotypic changes which have accompanied the evolutionary differentiation of the three species. In our effort to do this, we describe here the Gand C-band patterns of their chromosomes, to determine the degree of karyotypic homology and distribution of constitutive heterochromatin. In addition, DNA specific fluorochromes are used to examine the homologous nature of the sequences within the heterochromatic regions of these species' karyotypes.
TL;DR: An exact solution of the vacuum Brans-Dicke (BD) field equations has been obtained for the metric tensor of a spatially homogeneous and anisotropic Bianchi type-I cosmological model as mentioned in this paper.
Abstract: An exact solution of the vacuum Brans-Dicke (BD) field equations has been obtained for the metric tensor of a spatially homogeneous and anisotropic Bianchi type-I cosmological model. The Kasner metric is shown to be a special case. Some physical properties of the model have been discussed.
TL;DR: In this article, some LRS Bianchi type-V cosmologic models representing a viscous fluid distribution with a null electromagnetic field and streaming neutrinos have been investigated and various physical and kinematical features of these models have also been explored.
Abstract: In this paper we have investigated some LRS Bianchi type-V cosmologicla models representing a viscous fluid distribution with a null electromagnetic field and streaming neutrinos. Various physical and kinematical features of these models have also been explored.
TL;DR: In this article, the effect of Cd2+ (4ppm) on the uptake of nitrate by Anacystis nidulans IU 625 (ATCC 27144) was investigated by monitoring short-term uptake rates at different NO3- levels (1-20mM).
Abstract: The effect of Cd2+ (4ppm) and a combination of Cd2+ with the non-inhibitory levels of metals like Ca2+ (150ppm), Zn2+ (2ppm), and Hg2+ (0.04ppm) on the uptake of nitrate by Anacystis nidulans IU 625 (ATCC 27144) was investigated. The NO3- uptake kinetics was studied by monitoring short-term uptake rates at different NO3- levels (1-20mM). The values for Vmax (0.8μmol/μg protein/hr) and half saturation constant for uptake (Km 3.03mM) were obtained employing the double reciprocal plot. A 4ppm level of Cd2+ inhibited 50% of the NO3- uptake rate (at saturating NO3- level) compared to Cd2+-less control. Cd2+ inhibition of NO3- uptake (Km 5.88mM) was alleviated as a result of competitive interaction by either Ca2+ (Km 4.34mM) or Zn2+ (Km 4.08mM). Hg2+ ions, however, interacted synergistically with Cd2+ (Km 12.5mM). There was no change in the uptake capacity (Vmax 0.8μmol/μg protein/hr) for NO3- under various treatments.
TL;DR: In this article, the authors examined the Oligocene-Miocene transition in three Deep Sea Drilling Project sites (DSDP 289, 208, 206) in the South Pacific ranging from the equator to temperate regions.
Abstract: Qualitative and quantitative planktonic foraminiferal trends have been examined across the Oligocene-Miocene transition in three Deep Sea Drilling Project sites (DSDP 289, 208, 206) in the South Pacific ranging from the equator to temperate regions. Primary objectives were to determine main changes in planktonic foraminiferal assemblages over the Oligocene-Miocene transition. Of available planktonic foraminiferal datums in the South Pacific sequences, Globoquadrina dehiscens is the most useful for designation and correlation of the Oligocene-Miocene boundary. The stratotype Aquitanian stage (earliest Miocene) in France contains Gq. dehiscens . Although the base of the Aquitanian stratotype is marked by an unconformity, biostratigraphic data elsewhere within the basin suggest that the evolutionary appearance of Gq. dehiscens occurred close to the time of the oldest stratotypic sediments. Therefore, the evolutionary appearance of Gq. dehiscens seems to represent one of the most reliable datums for interregional correlation of the Oligocene-Miocene boundary, one that occurs within the biostratigraphic range of Globorotalia ( Fohsella ) kugleri and marks the boundary between zones N4A and N4B. Globigerinoides first evolved during the late Oligocene and is not coincident with the Oligocene-Miocene boundary. Unlike the Eocene-Oligocene boundary, the Oligocene-Miocene boundary is not marked by a crisis in the Oligocene planktonic foraminiferal assemblages. Most Oligocene forms continue their range upward into the early Miocene, where most are replaced by typical Neogene forms. The only important Oligocene phylogenetic lineage to be essentially eliminated during the Oligocene-Miocene transition is Catapsydrax , the last important forms of which disappeared during earliest Miocene. Evolution of Gq. dehiscens effectively heralds the beginning of major evolutionary radiations in planktonic foraminifera that led to the distinctive Neogene phylogenies. Appearance of this form was followed by evolutionary radiation of Globigerinoides into a number of species; initial evolution of Globorotalia ( Globoconella ) incognita , which forms the earliest ancestral form of Globoconella ; evolution of the Globigerina woodi group; Sphaeroidinellopsis disjuncta (the ancestral stock of the Sphaeroidinellopsis - Sphaeroidinella lineage); Globorotalia ( Fohsella ) peripheroronda from Gr. (F.) kugleri (representing the continued development toward the classic Fohsella forms); and typical forms of the Dentoglobigerina stock represented by Dentoglobigerina altispira . These evolutionary radiations are reflected by a general increase in simple species diversity through early Miocene. At all three sites, species diversity is lowest in the interval near the Oligocene-Miocene boundary. Among the three sites examined, diversity is highest in warm-subtropical Site 208, because at this latitude faunas include both tropical and temperate forms. The earliest Miocene is marked by high frequencies of Gr. (F) kugleri in tropical areas and Gq. dehiscens in warm-subtropical to temperate areas.
TL;DR: C. batrachus exposed to 5 ppm of lead nitrate for 150 days exhibited marked inhibition of gonadal growth and brain, testis and ovary showed decreased in cholesterol and lipid levels whereas the liver showed an elevation of both.
TL;DR: In this article, the effect of a uniform transverse magnetic field on the Couette flow of an electrically conducting fluid between two parallel plates for impulsive and uniformly accelerated motion of one of the plates is discussed.
TL;DR: Two cases of Paget's disease of the male breast were detected in a retrospective histopathological review of 27 cases of male breast cancer treated during a period of 13 years from 1966 through 1978.
Abstract: Two cases of Paget's disease of the male breast were detected in a retrospective histopathological review of 27 cases of male breast cancer treated during a period of 13 years from 1966 through 1978. The clinico-pathological data on these two rare cases have been compared with the 23 histologically documented cases of Paget's disease of the male breast from the literature.
TL;DR: The recent results of Swartzendruber et al. as discussed by the authors suggest a shifting of the α −( α + α 2 ) transition point to lower aluminium concentrations and to higher temperatures than those proposed by Blackburn.
TL;DR: A light-sensitive rhythm with a period of about 24 hr is involved in the photoperiodic induction of premigratory fattening and weight gain in Blackheaded buntings and this endogenous circadian rhythm can be entrained by an ultrashort photophase of 3 h if the latter is coupled with scotophases of specific duration.
Abstract: This investigation attempts to identify the mechanism(s) involved in the fat deposition in a photoperiodic migratory species, the Blackheaded bunting (Emberiza melanocephala) Groups of photosensitive male buntings were exposed to resonance, interrupted night, and ultra-short-day light cycles for 35, 42 and 75 days, respectively Birds were weighed at the beginning and at the end of the experiments Those exposed to ultra-short-day light cycles were also weighed at critical intervals during the treatment period Our results indicate that: (a) a light-sensitive rhythm with a period of about 24 hr is involved in the photoperiodic induction of premigratory fattening and weight gain in Blackheaded buntings: (b) buntings possess a bimodal pattern 'of sensitivity to photoperiods that induce fattening, and (c) this endogenous circadian rhythm can be entrained by an ultrashort photophase of 3 h if the latter is coupled with scotophases of specific duration
TL;DR: In this article, it was shown that both rapid solidification from the liquid state and vapour deposition of an Al-2wt.%Rh alloy resulted in the formation of a supersaturated solid solution.
Abstract: Both rapid solidification from the liquid state and vapour deposition of an Al-2wt.%Rh alloy resulted in the formation of a supersaturated solid solution. During decomposition an Al13Rh4 phase with a monoclinic structure (a = 1.636 nm, b = 0.805 nm, c = 1.279 nm and β = 107.77°) was detected in both cases. It is shown that this is an equilibrium phase. Possible reasons for the formation of Al13X4-type phases are also discussed.
TL;DR: A new polyoxygenated chromone- C -glucoside, named biflorin, was isolated from the roots of Pancratium b iflorum collected at flowering time.
TL;DR: In this paper, the authors made trace-element determinations of 15 coal samples in order to know their distribution, behaviour and associations with the organic and inorganic fractions in the coal.
TL;DR: The gonadal responses of female rosefinches (Carpodacus erythrinus) have been described and investigated with lighting regimens of various combinations, and it is evident that the ovarian cycle is photoperiodically regulated.
Abstract: The gonadal responses of female rosefinches (Carpodacus erythrinus) have been described and investigated with lighting regimens of various combinations. It is evident that the ovarian cycle is photoperiodically regulated. The rosefinch has a definite photoperiodic threshold to its gonadal activities, the rate of growth being greater in longer photoperiods. A refractory period has also been found in its ovarian cycle, which requires at least 7 weeks of short day treatment for its dissipation.
TL;DR: In this article, a flow past an infinite vertical isothermal plate started impulsively in its own plane in a viscous incompressible and electrical conducting fluid has been presented in a rotating system.
Abstract: The flow past an infinite vertical isothermal plate started impulsively in its own plane in a viscous incompressible and electricalfy conducting fluid has been presented in a rotating system. The magnetic Reynolds number is assumed small so that the induced magnetic field can be neglected. The governing equations of the flow are solved by defining a complex variable with the help of the Laplace transform technique. The influence of the various parameters, occurring into the problem, on the axial and transverse components of the velocity and skin-friction is extensively discussed with the help of graphs and table.
TL;DR: In the thyroidectomized, adult male redheaded bunting exposed to a LD cycle of 1509, there were no significant changes in body weight, gonad size, respiratory rates of whole body, liver, muscle, red blood cell number, hemoglobin concentration, or hematocrit, unlike in intact birds as discussed by the authors.
TL;DR: In this paper, the authors developed analytical solutions for the dispersion problem in non-adsorbing and adsorbing, semi-infinite porous media in which the flow is one dimensional and the average flow velocity is unsteady.
Abstract: Analytical solutions are developed for the dispersion problem in nonadsorbing and adsorbing, semi-infinite porous media in which the flow is one dimensional and the average flow velocity is unsteady. The expression that states the direct relationship of the dispersion coefficient with seepage velocity is used to solve the unsteady dispersion flow problem by introducing a new time variable. The source concentration of the pollutant varies exponentially with time. The variation in seepage velocity with time is considered because of resistance in the flow. The graphical solutions are also obtained for a set of data assumed.
TL;DR: The activity of alkaline phosphatase in the various tissue components of the regenerating skin of a cat-fish has been studied and the functional significance of this enzyme is discussed in relation to the granulation tissue formation.
Abstract: The activity of alkaline phosphatase in the various tissue components of the regenerating skin of a cat-fish has been studied. A marked increase in alkaline phosphatase activity in the cells of migrating epithelium has been correlated with their highly active state. High alkaline phosphatase in the basal cells after 2 days has been found to have played an important role in cell multiplication and differention. The functional significance of this enzyme is discussed in relation to the granulation tissue formation.
TL;DR: The results from both series of experiments suggest that the female redheaded bunting uses photoperiods as a primary environmental source of information in regulating its reproductive responses.
Abstract: Two series of experiments were performed with photosensitive female redheaded buntings. In the first series, birds were exposed to various cycles (8L/16D, 12L/12D, 13L/11D, 15L/9D, and 20L/4D) for 35 days. In the second, birds were maintained for a period of 120 days under long day lengths (15L/9D), short day lengths (8L/16D), and normal day lengths (NDL). Periodic laparotomies of birds under these schedules indicated that long days induced ovarian growth followed by regression and refractoriness, short days were ineffective, and that the birds in NDL showed ovarian growth during periods in the summer of increasing day lengths, followed by spontaneous regression. Groups of photorefractory birds in long days were transferred to short days (8L/16D) for different periods in order to terminate the refractoriness before returning them to 15L:9D for another 20 days. The results from both series of experiments suggest that the female redheaded bunting uses photoperiods as a primary environmental source of information in regulating its reproductive responses. The threshold for its gonadal activities is a photoperiod of 12–13 h daily. A period of insensitivity (photorefractoriness) develops in buntings that are photostimulated, requiring about 8 weeks of short days for its termination.