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  • Springer  (811)
  • Wiley  (197)
  • Oxford University Press  (104)
  • American Institute of Physics (AIP)  (68)
  • 1
    Publikationsdatum: 2016-09-07
    Beschreibung: Direct numerical simulations of Rayleigh-Taylor instability (RTI) between two air masses with a temperature difference of 70 K is presented using compressible Navier-Stokes formulation in a non-equilibrium thermodynamic framework. The two-dimensional flow is studied in an isolated box with non-periodic walls in both vertical and horizontal directions. The non-conducting interface separating the two air masses is impulsively removed at t = 0 (depicting a heaviside function). No external perturbation has been used at the interface to instigate the instability at the onset. Computations have been carried out for rectangular and square cross sections. The formulation is free of Boussinesq approximation commonly used in many Navier-Stokes formulations for RTI. Effect of Stokes’ hypothesis is quantified, by using models from acoustic attenuation measurement for the second coefficient of viscosity from two experiments. Effects of Stokes’ hypothesis on growth of mixing layer and evolution of total entropy for the Rayleigh-Taylor system are reported. The initial rate of growth is observed to be independent of Stokes’ hypothesis and the geometry of the box. Following this stage, growth rate is dependent on the geometry of the box and is sensitive to the model used. As a consequence of compressible formulation, we capture pressure wave-packets with associated reflection and rarefaction from the non-periodic walls. The pattern and frequency of reflections of pressure waves noted specifically at the initial stages are reflected in entropy variation of the system.
    Print ISSN: 1070-6631
    Digitale ISSN: 1089-7666
    Thema: Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Publikationsdatum: 2016-02-13
    Print ISSN: 0195-928X
    Digitale ISSN: 1572-9567
    Thema: Physik
    Publiziert von Springer
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Materials research innovations 2 (1999), S. 278-282 
    ISSN: 1433-075X
    Schlagwort(e): Key words Ferroelectrics ; Phased array antenna ; Tunable devices ; Thin films
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract  Low loss, tunable dielectric materials are important for phased array antenna and other device applications. Various composites of barium strontium titanium oxide (BSTO) combined with other nonelectrically active oxide ceramics have been formulated for such uses. The dielectric constant and the loss tangents of these composites have been reduced to enhance the overall impedance matching and thereby lowering the overall insertion loss of the device. The material has been fabricated in bulk ceramic, thick film, and thin film form to address a broad range of frequency applications. The material fabrication methods and the electronic properties of these composites will be discussed in this article.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    Springer
    Applied microbiology and biotechnology 53 (2000), S. 732-735 
    ISSN: 1432-0614
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract  In the estimation of glycosidase activity by dinitrosalicylic acid (DNS) reagent, the stoichiometry of DNS reduction was reported to increase proportionately with the increase in the number of glycosidic linkages present in oligosaccharides liberated by the enzyme. The relationship between increases in DNS reduction and increases in the number of glycosidic bonds was found to be represented by a part of a rectangular hyperbola. The increase was optimum with disaccharide and insignificant when the degree of polymerization (DP) was ≥10. The difference did not arise as a result of the DNSA discriminating between mono- and oligosaccharide oxidation. The relationship stemmed from the acidity of the hydroxyl group adjacent to the reducing group, which repressed DNS reduction. The acidity is likely to decrease with an increase in oligosaccharide chain length. It is suggested that DNS reduction is actually optimum and uniform for all oligosaccharides of DP ≥ 10 and that it is minimum for monosaccharide. Thus the introduction of rectification factors in the estimation of glycosidase activities by the DNS method appears to be justified.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    ISSN: 1432-1203
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A chromosomal survey using standard lymphocyte cultures employing different media and G-banding techniques was initiated in 1984. This study became particularly important following the tragic gaseous exposure of the population in Bhopal at midnight on 2 December 1984. We have been able to formulate a chromosomal profile for each person whom we have studied; during 1986–1988, 154 persons were examined twice. Among seemingly normal individuals, as many as 20% might possess some chromosomal abnormality; of these, 50% may develop, at a later date, some kind of pathological complication (such as tumours, recurrent abortion or transmission of defects to their offspring). The people exposed to methyl isocyanate have repeatedly shown Robertsonian translocations, mostly in acrocentric chromosomes 13 and 21. Other types of translocations have been studied among all exposed (53) and normal (101) persons; the involvement of chromosomes 5, 9, 11, 14 and 16 is statistically significant (P= 〈0.001). One of the major clinical symptoms is dyspnoea; we have estimated that almost all seriously dyspnoeic patients have developed at least two categories of chromosomal aberrations, one of which is Robertsonian translocation, in at least 10% metaphases. Our chromosomal survey will be of significance because we are able to identify people with chromosomal aberrations that might be correlated with future pathological consequences of the accident. The “chromosomal load” that can be sustained with an apparently normal phenotype can also be measured.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    ISSN: 1432-0967
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: 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.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    Computational mechanics 14 (1994), S. 298-310 
    ISSN: 1432-0924
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract The unsteady viscous incompressible flow around a circular cylinder is studied numerically for high Reynolds number. The two dimensional Navier-Stokes equation in stream function-vorticity formulation is solved. A fractional step method is used to solve the stream function equation while the vorticity transport equation is solved using a third order upwinding scheme. The computed solutions by the finite difference method agree reasonably well with the available experimental and other computational results at a Reynolds number of 9500 and 4500. These comparisons are for the initial stages of flow evolution when the wake bubble is symmetric.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Colloid & polymer science 208 (1966), S. 32-34 
    ISSN: 1435-1536
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Stärke isoliert aus Wasser Kastanie (Trapa Bispinosa Roxb) wurde in Amylose und Amylopektin mit konventioneller Methodik fraktioniert. An beiden, dem Amylose-Jod und Amylopektin-Jod-Komplex wurden spektrometrische Diagramme aufgenommen. Auch über die Kinetik des Abbaues dieser Komplexe wird berichtet.
    Notizen: Summary Starch isolated from water-chestnut (Trapa Bispinosa Roxb) was fractionated into amylose and amylopectin by conventional method. Spectrophotometric studies have been carried on each of amyloseiodine and amylopectin-iodine complex. The kinetics of the decomposition of these complexes have also been reported.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Publikationsdatum: 2016-07-29
    Beschreibung: Colloidal particles were exposed to a random potential energy landscape that has been created optically via a speckle pattern. The mean particle density as well as the potential roughness, i.e., the disorder strength, were varied. The local probability density of the particles as well as its main characteristics were determined. For the first time, the disorder-averaged pair density correlation function g (1) ( r ) and an analogue of the Edwards-Anderson order parameter g (2) ( r ), which quantifies the correlation of the mean local density among disorder realisations, were measured experimentally and shown to be consistent with replica liquid state theory results.
    Print ISSN: 0021-9606
    Digitale ISSN: 1089-7690
    Thema: Chemie und Pharmazie , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Publikationsdatum: 2014-01-22
    Beschreibung: Trehalose-6-phosphate phosphatase (TPP) catalyzes the final step in the biosynthesis of the anti-stress sugar trehalose. An 82 kDa TPP enzyme was isolated from Candida utilis with 61% yield and 43-fold purification. The protein sequence, determined by N-terminal sequencing and MALDI-TOF analysis, showed significant homology with known TPP sequences from related organisms. The full length gene sequence of TPP of Candida utilis was identified using rapid amplification of cDNA ends - PCR reaction (RACE-PCR). The gene was cloned and expressed in E. coli BL21. Recombinant TPP enzyme was isolated using affinity chromatography. CD spectroscopy and steady state fluorescence revealed that the structural and conformational aspects were identical in both native and recombinant forms. The biochemical properties of the two forms were also similar. K m was determined to be ∼0.8 mM. Optimum temperature and pH was found to be 30 °C and 8.5 respectively. Activity was dependent on the presence of divalent cations and inhibited by metal chelators. Methylation mediated regulation of TPP enzyme and its effect on the overall survival of the organism under stress were investigated. The results indicated that enhancement of TPP activity by methylation at the Cysteine residues increased resistance of Candida cells against thermal stress. This work involves extensive investigations towards understanding the physico-chemical properties of the first TPP enzyme from any yeast strain. The mechanism by which methylation regulates its activity has also been studied. A correlation between regulation of trehalose synthesis and survivability of the organism under thermal stress was established. J. Cell. Physiol. 9999: XX–XX, 2014. © 2014 Wiley Periodicals, Inc.
    Digitale ISSN: 1097-4652
    Thema: Biologie , Medizin
    Publiziert von Wiley
    Standort Signatur Erwartet Verfügbarkeit
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