Browsing by Issue Date, starting with "1992"

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Preparation of high-Tc superconducting thin films of Tl-Ca-Ba-Cu-O by the chemical spray pyrolysis technique
(1992) K.K. Verma; A.K. Sexena; A.K. Singh; R.S. Tiwari; O.N. Srivastava
Thin films of the Tl-Ca-Ba-Cu-O system have been prepared on MgO and YSZ single-crystal substrates by a simple chemical process (the spray pyrolysis technique). Since Tl is toxic, the Tl-Ca-Ba-Cu-O films were prepared by a two step process. Firstly, precursor (Ca-Ba-Cu-O) films were prepared followed by diffusion of Tl derived by vaporizing Tl2O3 in a closed system under oxygen flow. A new feature found in the present investigation is that the Tc (R=0) of the Tl-Ca-Ba-Cu-O films has been found to depend upon the microstructural characteristics of the precursor films which can be varied by annealing these films. The Tc (R=0) of the Tl-Ca-Ba-Cu-O HTSCs films prepared from the annealed precursor films has been found to be higher than in the films prepared from the as-deposited precursor films. As, for example, in the case of a film on a MgO substrate, the Tc (R=0) has been enhanced from approximately 90 K to approximately 98 K. The highest T c obtained by the authors for the films synthesized from the annealed precursor films on YSZ substrates corresponds to approximately 103 K. The XRD reveals the biphasic (2223/2122) nature of the films. The microstructural characteristics of the films as monitored by SEM reveals the partially oriented nature of the Tl-Ca-Ba-Cu-O film.
On Preuss' connectedness concept in FTS
(1992) R. Lowen; Arun K. Srivastava
the principal aim of this paper is to examine the extent to which certain connectedness concepts in FTS can be viewed as connectedness in Preuss' sense i.e., as subclasses of [FTS] which equal CE:= {X ε{lunate} ∥FTS∥ ∥ f{hook} ε{lunate} FTS(X, Y), Y ε{lunate} E ⇒ f{hook} is constant}, for some E ⊂ ∥FTS∥. Two new connectedness concepts in FTS, which subsume an existing concept, are shown capable of being so viewed while it turns out that certain existing, otherwise good, connectedness concepts cannot be so viewed. © 1992.
Increased production of interleukin-1 and tumor necrosis factor by human monocytes treated in vitro with cisplatin or other biological response modifiers
(1992) Ajit Sodhi; Kalpana Pai
Supernatants collected from cisplatin, lipopolysaccharide (LPS), muramyl dipeptide (MDP) or interferon-gamma (IFN-γ) treated human monocytes enhance the thymocyte proliferation by a submitogenic concentration of concanavalin A. Also supernatants collected from cisplatin or IFN-γ treated monocytes demonstrated enhanced cytotoxicity against actinomycin-D treated L 929 cells, suggesting that cisplatin or rIFN-γ treated monocytes release tumor necrosis factor (TNF) into the culture medium. The supernatant collected from untreated monocytes showed only little IL-1 and TNF activity. © 1992.
Emergence of Vibrio cholerae 01 resistant to vibriostatic agent 0/129
(1992) Gopal Nath; SuhasC. Sanyal
[No abstract available]
Hydatid cyst of the neck
(BMJ Publishing Group, 1992) Kundan Kumar; Ajay K. Khanna; Mahendra K. Misra
[No abstract available]
Coordination behaviour of pyridoxalisonicotinoyl hydrazone towards some 3d-metal ions
(1992) Genda Singh; P.S.S.J. Shastry; R.K. Lonibala; T.R. Rao
The complexes of divale t manganese, cobalt, nickel, copper, zinc and the ligand pyridoxalisonicotinoyl hydrazone (PIH) are discussed in order to illustrate the behaviour of the ligand towards the metal ions in acidic and neutral media. The complexes [M(PIH-2H)(H2O)3](M = Mn, Co and Zn), [cu(pih-2h)(h2O)2]2, [cu(pih)c1(H2O)]2 2+ and [Ni(PIH)Cl2(H2O)] have distorted octahedral structures. The isostructural crystalline complexes, [m(pih)c12]2 (M= Mn, Co andZn) are isolated from hot solutions. The electronic spectral data of cobalt in conjunction with infrared, NMR and magnetic measurements enables the assignment of the formula [m(pih) 2][MC14] to these complexes. The anion is tetrahedral while the cation has an octahedral chromophore. Characterization data indicates that [Ni(PIH-2H)H2O] has a four-coordinated square-planar chromophore. The IR, and 1H 13 C NMR spectral data indicate that PIH behaves as a neutral tridentate ligand in the chloro complexes and as a dinegative, tridentate species in the deprotonated complexes. © 1992, Taylor & Francis Group, LLC. All rights reserved.
Influence of long- term aging and superimposed creep
(1992) N. Gope; T. Mukherjee; D.S. Sarma
In an effort to understand the effects of long-term aging at high temperatures and those of the superimposed creep stresses on the microstructural variations in a 0.50Cr-0.50Mo-0.25V steel, the shoulder and gage portions of the specimens subjected to stress rupture tests at 500 °C and 540 °C have been studied by transmission electron microscopy. The optical microstructure, in the normalized and tempered condition, consists of about 95 pct ferrite with the remainder bainite. The ferrite has an extremely fine precipitation of vanadium carbide (VC) as interphase precipitate as well as in random distribution. In the bainitic area, M 3C is present in the globular as well as plate-like morphology. Specimens ruptured at 500 °C and 540 °C were selected for transmission electron microscopic study. Both the interphase precipitates and randomly distrib- uted precipitates of VC coarsen considerably due to prolonged exposure at elevated tempera- tures, and ultimately fine M 2C platelets nucleate and grow on either side of these precipitates, resulting in the formation of the so-called H-carbides. The superimposed creep stress has a marginal effect on the coarsening kinetics of VC but has enhanced its precipitation along dis- locations and has promoted the formation of H-carbides. © 1992 The Minerals, Metals and Materials Society, and ASM International.
Two photon optogalvanic spectrum of the D-X system of HgBr
(Springer India, 1992) G. Ullas; V. Kumar; S.B. Rai
Two photon laser optogalvanic spectrum of the D-X system of HgBr molecule has been recorded using Nd-YAG laser pumped dye laser for the first time. A large number of new bands involving higher vibrational levels have been observed. Isotopic heads due to the two bromine isotopes have been observed and used in fixing the vibrational assignment. Vibrational constants for the X and D states of the two isotopic molecules have been determined. © 1992 Indian Academy of Sciences.
Hand Preference in India
(1992) Manas K. Mandai; Geetika Pandey; Shyam K. Singh; Hari S. Asthana
The degree of asymmetric handedness was measured by a 22‐item hand preference questionnaire in a sample of 442 Indian subjects. Factor analysis of the data for right‐handers yielded four item‐clusters: Gross activities, skilled activities (general), skilled activities (specific), and activities subject to social pressure. Identical analysis for left‐handers yielded three item‐clusters: Activities that are executed with difficulty, with ease, and with greater frequency. The degree of asymmetric handedness in right‐handers was positively (high) correlated with an index of social pressure against left‐hand use, especially for the items, writing and eating. The correlation was negative (moderate) in left‐handers, however, who had preferred the right hand for eating purposes. © 1992 International Union of Psychological Science
Foliar injury and leaf diffusive resistance of rice and white bean in response to SO2 and O3, singly and in combination
(1992) B.D. Tripathi; Anamika Tripathi
Plants of rice (Oryza sativa) and white bean (Phaseolus vulgaris) were exposed to 524 μg m-3 SO2, 392 μg m-3 O3 and a mixture of both gases, i.e. 524 μg m-3 SO2 and 392 μg m-3 O3 to determine the visible foliar injury and leaf diffusive resistance. Response of leaf diffusive resistance was measured on upper and lower surfaces of leaves, i.e. the two unifoliate leaves of bean and the first, second and third primary leaves of rice. The difference in the response may be due to sensitive guard cells causing stomatal closure in the presence of O3, whilst a low concentration of SO2 caused the stomata to open. Thus, SO2 alone is known to decrease, and O3 tends to increase leaf diffusive resistance. However, exposure to both gases increases or decreases the resistance, depending on the species response. © 1992.
Nature and cosmic integrity a search in Hindu geographical thought
(Kluwer Academic Publishers, 1992) Rana P.B. Singh
The roots of Hindu geographic thought can be traced to the remote past, going back at least to c. 3500 BC. Formerly the unity of Nature and Man was expressed in the context of religious activities. The idea of nature and human integrity in Hindu thought depends upon ways in which people see and experience themselves, their sense of attachment to nature, and their ways of maintaining this. It is through symbolism, the main expression of mythological understanding, that one can gain insight into the relationships of humanity to Nature. Creation and incarnation myths describe the origin of organic life and of its five basic elements. The integrity of dwelling in space is expressed through the notion of home. Religion plays a vital role in the Hindu quest for harmony between nature and humanity. Mystics understand the roots of the Tao but not its branches; scientists understand its branches but not its roots. Science does not need mysticism and mysticism does not need science; but man needs both (Capra 1976, p. 297). © 1992 Kluwer Academic Publishers.
Photobiological production of ammonia by an L-methionine-DL-sulfoximine-resistant mutant of cyanobiont Nostoc ANTH
(1992) S. Singh
[No abstract available]
Multiple melting due to secondary crystallization in polymers
(Kluwer Academic Publishers, 1992) P.N. Chaturvedi
[No abstract available]
Oocyte maturation in Clarias batrachus. III. Purification and characterization of maturation-inducing steroid
(Kluwer Academic Publishers, 1992) S. Haider; N.V. Rao
Maturation-inducing steroid (MIS) in the Indian female catfish, Clarias batrachus, was purified and characterized from the incubation medium in which fully grown but immature folliculated oocytes were incubated with salmon gonadotropin (SG-G100) for 36 h. Maturation-inducing (MI) activity of residues obtained at various steps of extraction and purification was assessed by in vitro germinal vesicle breakdown (GVBD) assay using folliculated oocytes of C. batrachus. The post incubation medium was extracted with diethyl ether. The ether phase was partitioned using 50% methanol plus n-hexane. The methanol phase which had MI activity was fractionated into 7 fractions using reverse-phase high-performance liquid chromatography. Of these 7 fractions, fraction 3 was found to be active in having MI ability and identified as 17 α,20β-dihydroxy-4-pregnen-3-one (17α,20β-diOHprog). The authenticity of 17α,20β-diOHprog as the major follicular mediator of gonadotropin-induced oocyte maturation was further confirmed by thin-layer chromatography (TLC) in which fraction 3 was run along with authentic 17α,20β-diOHprog standard. This investigation gives a direct evidence that 17α,20β-diOHprog is the major naturally occurring MIS in Indian female catfish, C. batrachus. © 1991 Kugler Publications bv.
Effects of muscarinic receptor agonists and antagonists on rat brain serotonergic activity
(Springer-Verlag, 1992) S.K. Bhattacharya; A.P. Sen
The effects of some muscarinic M1 and M2 receptor agonists and antagonists on rat brain serotonergic activity was assessed by noting their effects on the levels of 5-hydroxytryptamine (5-HT) and its major metabolite, 5-hydroxyindole acetic acid (5-HIAA), estimated by a high pressure-liquid Chromatographie (HPLC) technique. The muscarinic M1 receptor agonists, arecholine and McN-A-343, and the M2 receptor agonists, gallamine and AF-DX 116, induced a dose-related decrease in the concentrations of both 5-HT and 5-HIAA. On the contrary, scopolamine and the selective M1 receptor antagonist, pirenzepine, increased the levels of the amine and its metabolite. The anticholinesterase agent, physostigmine, and the putative M2 receptor agonist, carbachol, induced a dose-related dual effect, with the smaller doses decreasing and the higher doses increasing 5-HT and 5-HIAA concentrations. The results indicate that an inverse relationship exists between the cholinergic and serotonergic neurotransmitter systems in the rat brain due to the likely presence of muscarinic heteroreceptors on serotonergic neurones. The data also indicates that though physostigmine and carbachol may function as M2 receptor agonists, they lose their receptor specificity on dose increment. © 1992 Springer-Verlag.
Phosphorus uptake by immobilized cells of the alkali‐tolerant cyanobacterium oscillatoria amphibia ag. ex gomont
(1992) A.K. Singh; Alka Dwivedi; H.D. Kumar
The phosphorus removal potential of the bloom‐forming, alkali‐tolerant cyanobacterium Oscillatoria amphibia was studied by entrapping and immobilizing it in calcium alginate. The uptake kinetics for orthophosphate‐phosphorus (PO4‐P) were determined by growing O. amphibia in Jaworski medium (pH 9) in 14.6 Wm‐2 light intensity at 24±1°C. The pH of the culture medium increased to 11.0 during growth. This facilitated the maintenance of unialgal cultures in the absence of any contaminants. Immobilized filaments showed potential capability of phosphorus accumulation. A stocking biomass of 0.4 μg chl a bead‐1 at external pH 9 was found to be suitable for rapid phosphorus removal. Phosphorus uptake kinetics of immobilized filaments were also dependent on the initial phosphorus concentration. These findings may be useful for designing a bioreactor to optimize phosphorus removal using an immobilized cyanobacterial system. © 1992 Publications Division Selper Ltd.
Fine needle aspiration cytology in the diagnosis of prostatic enlargements.
(1992) N.C. Aryya; R.K. Yadav; P.B. Singh; S. Khanna; K. Pandey
One hundred patients with enlarged prostate were subjected to fine needle aspiration cytology and histopathologic examination of prostate. The results have been found encouraging. The cytodiagnostic accuracy rate was 99 p.c. in identification of benign or malignant nature of the lesions and 94 p.c. in cytologic specific diagnosis (exactly similar to histopathologic diagnosis). The technique was simple, rapid, economical, reliable, easy to repeat and highly suitable for outpatients. The procedure can routinely be adopted in places where facilities for preparation of paraffin section do not exist or when quick diagnosis is required.
Ozone: Concentration variabilities in a seasonally dry tropical climate
(1992) Jitendra Pandey; Madhoolika Agrawal
This paper reports seasonal and diurnal variations in the ambient air concentrations of ozone in Varanasi city, India for the years 1989 and 1990. Different monitoring zones were established in the city on the basis of pollution sources, traffic densities, and structure of built-up areas. At most of the monitoring stations, two-hourly ozone concentrations frequently exceeded 60 μg m-3 (0.03 ppm) during summer months. However, the zone dominated by residential colonies, offices, and cultivated land showed maximum O3 concentrations less than 60 μg m-3 (0.03 ppm). Higher concentrations of ozone were mainly recorded in warmer months between 11 am to 4 pm. The highest concentration (2-h mean) of 160 μg m-3 (0.08 ppm) O3 was recorded in the month of April at Zone I which was mainly due to emissions from heavy-duty automobiles. Monthly average ozone concentrations were significantly correlated with temperature (r = 0.69), relative humidity (r = 0.81), wind speed (r = 0.76), and atmospheric pressure (r = -0.46). The frequency distribution of 2-h mean ozone concentrations was close to the logarithmic normal. Maximum 2-h mean O3 concentrations in some areas of Varanasi city were above the limit that has been shown to cause significant vegetation damage. The temporal variation in ozone concentrations was mainly due to the variations in meteorological conditions. © 1992.
Perinatal hypophosphatasia.
(1992) O.P. Mishra; O.P. Sharma; B.D. Bhatia; M. Kumar; B.K. Das; A. Prakash; V. Bhargava
[No abstract available]
Karyology of Nitella from South India
(1992) B.V.S. Subrahmanyam; Y.B.K. Chowdary
Karyological investigations on four taxa of Nitella have been carried out. The chromosome counts recorded are all new records to the respective taxa. Chromosome numbers are n=9, 27, 12 and 9 to Na furcata subspa flagellifera f. flagellifera RDW, Na furcata subsp. megacarpa f. megacarpa (T. F. A.) RDW, N. pseudoflabellata var. elegans (Pal) RDW and N. gracilis f. intermedia (Nordst.) RDW, respectively. N. graeilis f. intermedia is karyologically investigated from India for the first time. © 1992, Japan Mendel Society, International Society of Cytology. All rights reserved.