ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (1,311)
Collection
Language
  • 1
    Publication Date: 2016-09-07
    Description: 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
    Electronic ISSN: 1089-7666
    Topics: Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0277-5387
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0924
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: 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.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: 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.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: 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.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1433-075X
    Keywords: Key words Ferroelectrics ; Phased array antenna ; Tunable devices ; Thin films
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: 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.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: 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.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1520-5851
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract Vibrio cholerae belonging to the recently described serogroup 0139, which are responsible for the current cholera epidemics in India and Bangladesh, were shown to express pilus-like structures partially cross-reacting with the toxin-coregulated pilus of V. cholerae strain (0395) belonging to the 01 serogroup and classical biotype. The 0139 pili were composed of 20 kDa subunit proteins which were antigenically related to the 20 kDa pilus protein of another diarrhoeagenic non-01 V. cholerae strain (serogroup 034) isolated earlier. The pili described in this study were found to be involved in the intestinal colonization process and, therefore, may contribute towards the virulence of the 0139 epidemic isolates.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: An extracellular amyloglucosidase (56 kDa) of Termitomyces clypeatus which was accumulated intracellularly in absence of Krebs cycle acids in dextrin medium, remained mostly inside the plasma membrane. The enzyme was localised in mycelial vacuoles as a sucrase-amyloglucosidase aggregate. The intracellular pool contained both the free sucrase and the aggregate, while vacuoles contained only aggregate without any free enzyme. The aggregate, partially purified to PAGE homogeneity, contained amyloglucosidase and sucrase in the ratio of 1:1. A cellular regulation, influenced by the presence of Krebs cycle acids, was indicated to be present at the level of exocytosis of vacuolar enzyme.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...