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  • 1
    Electronic Resource
    Electronic Resource
    Wave propagation in marine sediments and water saturated soils (1962)
    Springer
    Pure and applied geophysics 52 (1962), S. 27-40 
    Details
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary A unification of the theories of Biot and Weiskopf has been made to form the suitable equations of motion for porous water saturated soils and marine sediments. It has been shown that the velocities of the body waves depend on the direction of propagation. In the vertical direction there are three, one distortional and two dilatational waves. In the horizontal direction there are two dilatational and two distortional waves. Finally, propagation of Love waves and Rayleigh waves have been discussed. Suitable potential functions have been derived to find the frequency equation for Rayleigh waves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01995997
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  • 2
    Electronic Resource
    Electronic Resource
    The constitution of ajmaline (1953)
    Springer
    Cellular and molecular life sciences 9 (1953), S. 254-256 
    Details
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Zusammenfassung Das IR.-Absorptionsspektrum des Alkaloids Ajmalin zeigt die typische (7,24 µ) in der Seitenkette (festgestllt mitKuhn-Roth); bei 5,92 µ erscheint die Bande der Karbonylgruppe. Ajmalin wurde durch Abbau mit Selen in Ind-N-methyl-harman übergeführt. Durch Kalischmelze lässt sich Ajmalin in eine kristalline Base (in kleiner Menge), eine stickstoffreie Säure und Indol-2-Karbonsäure aufspalten. Auf Grund dieser Spaltstücke wurde eine mögliche Strukturformel für Ajmalin diskutiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02172433
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  • 3
    Electronic Resource
    Electronic Resource
    The role of telomeres at anaphase (1962)
    Springer
    Chromosoma 13 (1962), S. 315-327 
    Details
    ISSN: 1432-0886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. Chromosomes ofAllium cepa, Tradescantia virginiana andT. paludosa were studied at mitosis in order to investigate the behavior of telomeres at anaphase. The studies were made in untreated fixed material, in cochicine treated cells, and in living staminal hairs. 2. InAllium cepa andT. virginiana chromosomes of untreated material, when the kinetochores start separating to opposite poles at early anaphase of mitosis, the median regions of the arms separate first, the proximal regions next and the telomeres last. 3. To study which region of the arms outside the proximal regions was involved in holding the sister chromatids together, 736 chromosome arms of completely flattened chromosomes were analyzed in colchicine treated cells ofA. cepa. In 14.9% the delayed separation involved the whole arm, in 2.8% it was in the median region, in 8.9% it was close to the telomere, and in 71.0% of the cases it was well localized at the telomere. 4. The colchicine treatment causes a change in the timing of the separation process in bothA. cepa andT. virginiana. When this treatment is applied the proximal regions of the arms separate later than the ends. 5. A study was made at mitosis of the whole chromosome complement ofAllium cepa. 1472 chromatid arms were analyzed and measured. All the 8 chromosomes of the haploid set ofA. cepa can be identified in well flattened cells. To find out whetherthere is any correlation between the division cycle of the telomere region and arm length (the distance telomere—kinetochore), an analysis was made of 736 chromosome arms. The 16 arms of the complement were grouped according to their length. Group I contains the two smallest arms and group IV the three largest. A statistical analysis of the data shows that there is a significant difference between the delayed separation at the ends of small versus longer arms. A χ2 of group I versus groups II, III, and IV gives the value 12.71 with P〈 0.001. The telomeres which are situated closer to the kinetochore separate earlier than those that are situated further away. This is not interpreted as being due to a mechanical effect of the kinetochore, because the proximal regions which are situated between the kinetochores and the telomeres, separate later than the telomeres of all groups of arms. 6. Studies of mitotic chromosomes were madein vivo in the staminal hairs ofT. virginiana andT. paludosa. At anaphase the telomeres can be seen to separate last just as in the fixed untreated material. 7. When the sister chromatids of an arm separate at early anaphase the telomere is considered to have the role of the fulcrum of a lever. The two arms of a chromosome are lifted as levers by the kinetochore and in the telomeres they get their point of support. In short arms such an adaptation is not necessary, as the telomeres are quite close to the kinetochore, but in long arms, as those of the species studied here, this adaptation results in an easier and more regular separation of the arms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00577046
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  • 4
    Electronic Resource
    Electronic Resource
    Antibiotics from higher fungi (1952)
    Springer
    Archives of microbiology 18 (1952), S. 349-355 
    Details
    ISSN: 1432-072X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Peculiarities of antibiotic production by higher fungi (Hymenomycetes) are discussed, incidentally the condition for antibiotic production by Penicillium patulum is referred to. Antibacterial action of Psalliota campestris (wild variety) studied in the laboratory is fully described, it is active against Salmonella typhi, Escherichia coli and Staphylococcus aureus. In clinical trials in typhoid cases in our hospitals filtrates used orally and intramuscularly, are giving encouraging results. Laboratory study of antibacterial action of Marasmius campanella has been completed with a view to application to clinical trials in future.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00409486
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  • 5
    Electronic Resource
    Electronic Resource
    Influence of a mixed Al2O3+Cr2O3 superficial coating on the non-isothermal oxidation behavior of Fe and Fe-Cr alloys (1992)
    Springer
    Oxidation of metals 37 (1992), S. 95-108 
    Details
    ISSN: 1573-4889
    Keywords: non-isothermal ; oxidation ; Al2O3+Cr2O3 coatings ; Fe, Fe-Cr alloys
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The non-isothermal oxidation behavior of electrolytic-grade iron and Fe-Cr alloys in dry air has been studied using linear heating rates of 6 K/min, 10 K/ min, and 15 K/min up to a final temperature of 1273–1473 K. Some of the iron and iron-chromium alloy samples were given a surface treatment by dipping them in an aqueous solution containing both Cr and Al ions before their oxidation studies. This pretreatment has resulted in improved oxidation resistance and scale adherence as depicted by no scale rupture even after a second thermal cycle. Mass changes were recorded gravimetrically, and scales have been characterized by SEM, EPMA, and x-ray diffraction analyses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00665633
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  • 6
    Electronic Resource
    Electronic Resource
    A superficial coating to improve high-temperature-oxidation resistance of a plain-carbon steel under nonisothermal conditions (1994)
    Springer
    Oxidation of metals 41 (1994), S. 65-79 
    Details
    ISSN: 1573-4889
    Keywords: plain-carbon steel ; oxidation ; high temperature ; nonisothermal ; superficial coating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The nonisothermal oxidation behavior of 0.16% carbon steel at a heating rate of 7 K·min−1 up to a temperature of 1400 K in dry air ( $$P_{O_2 }$$ =21.27 kPa) is reported. It was envisaged to develop a cheaper and easily applicable superficial coating material for minimization of scale loss during high-temperature exposure. The coating material consisted of an aqueous slurry of bentonite and calcium silicide mixture. Such a coating material when applied superficially on the steel surface not only enhances oxidation resistance but also helps in forming an adherent oxide scale to the alloy substrate even up to a third cycle of exposure to 1400 K. Postoxidation analyses of the alloy-scale combination using XRD, SEM, and EDS revealed the formation of a barrier layer comprised of complex silicates and aluminoferrite that provided improved oxidation resistance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01196643
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  • 7
    Electronic Resource
    Electronic Resource
    Improvement in the oxidation behavior of austenitic stainless steels by superficially applied, cerium oxide coatings (1994)
    Springer
    Oxidation of metals 41 (1994), S. 139-178 
    Details
    ISSN: 1573-4889
    Keywords: austenitic stainless steels ; isothermal ; cyclic ; oxidation ; superficial CeO2 coating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The influence of superficially applied CeO2 coatings on the isothermal-oxidation behavior, preceded by nonisothermal heating, as well as cyclic-oxidation behavior of three grades of austenitic stainless steel (AISI-316, −321, and −304), in dry air is reported. The superficial coating had a thickness of 2.1 μm. The linear heating rate employed was 6 K min−1 up to a maximum temperature of 1423 K, and the isothermal holding temperature was 1273 K. The results clearly depict that CeO2 coatings not only reduced the rates of scale growth for all three varieties of steel but also imparted improved scale adhesion to the respective alloy substrates, as evident from the fact that the coated steels could withstand a number of thermal cycles without scale rupture. In the bare condition, 321-grade steel exhibited the best performance. However, in the presence of the coating, the improved performances of 316 and 321 grades were almost identical, whereas the 304 variety showed improvement only in the first cycle of exposure. The kinetics results have been substantiated by postoxidation analyses of the alloy/scale combinations by SEM, EDS, EPMA, and XRD techniques to reveal the role of rare-earthoxide coatings on the observed behavior.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01196647
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  • 8
    Electronic Resource
    Electronic Resource
    Influence of superficial coating of CeO2 on the oxidation behavior of AISI 304 stainless steel (1993)
    Springer
    Oxidation of metals 39 (1993), S. 221-229 
    Details
    ISSN: 1573-4889
    Keywords: non-isothermal ; oxidation ; 304 stainless steel ; superficial coating ; cerium oxide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The effect of a superficially-applied, cerium-oxide coating on the non-isothermal oxidation behavior of AISI 304 stainless steel in dry air has been investigated. The heating rate employed was 3 K/min up to a final temperature of 1423 K. The reactive oxide coating not only reduced the reaction rate but also facilitated scale adhesion to the alloy substrate. Post-oxidation analyses of the alloy/scale combination using optical microscopy, SEM, EDAX, and XRD provide evidence for a changeover in the mechanism of oxide growth from the scale/gas interface to the alloy/scale interface for the coated steel.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00665613
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  • 9
    Electronic Resource
    Electronic Resource
    Oxidation behavior of copper at high temperatures under two different modes of direct-current applications (1995)
    Springer
    Oxidation of metals 43 (1995), S. 185-215 
    Details
    ISSN: 1573-4889
    Keywords: copper ; oxidation ; direct current ; uninterrupted mode ; interrupted mode
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Oxidation kinetics of copper in the temperature range of 973–1173 K atP O 2=21.27 kPa exhibit enhancement and deceleration in the rates with changing polarity compared to normal oxidation under interrupted mode of directcurrent application. These conditions are achieved by connecting the oxidizing copper covered with an initially formed thin oxide film to the positive and negative terminal of a dc source, respectively. However, the influence of direction of the current is found to be opposite under uninterrupted mode of impressed current flow in the same temperature range. The effect of short-circuiting the metal to the outer oxide/air interface on the reaction kinetics is also reported. The rate of oxide-scale growth under normal condition, and two different modes of current applications as well as with shorting circuitry attachment conform to the parabolic growth law. The results pertaining to the two different modes of impressed current have been discussed considering both the phenomena of electrolysis of the oxide electrolyte and the polarization at the two phase boundaries. The enhancement and the reduction in rates under uninterrupted impressed current conditions are explained on the basis of increased and decreased average defect concentrations, respectively, within the oxide layer. The acceleration and deceleration in the rates under interrupted mode of current flow have been explained in the light of sustenance of a steeper and flatter electrochemical-potential gradient of defects, respectively, across the growing-oxide layer. The possible different responses of the metal/oxide and oxide/air interfaces to the impressed current brought into play by two different modes of current application, have enabled to display a better insight on the mechanistic aspects of scale growth under the influence of an externally applied current.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01047027
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  • 10
    Electronic Resource
    Electronic Resource
    Effect of short-circuiting on the oxidation kinetics of copper and its doped varieties in the temperature range of 523–1073 K (1996)
    Springer
    Oxidation of metals 46 (1996), S. 73-107 
    Details
    ISSN: 1573-4889
    Keywords: oxidation ; copper ; Li-doped copper ; Cr-doped copper ; short-circuiting ; Mott's parabola ; Wagner's parabola
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The influence of shorting circuitry attachment between metal-oxide and oxideoxygen interfaces on the oxidation kinetics of copper, lithium-doped copper (Li: 400 ppm), and chromium-doped copper (Cr: 12 ppm) have been studied in dry air $$(P_{O_2 } = 21.27kPa)$$ in the temperature range of 523–1073 K. Oxide film or scale growth under short-circuiting as well as under normal oxidation conditions conforms to the parabolic rate law. The oxidation kinetics under short-circuiting resulted in decreased rates for Cu and Li-doped Cu up to a temperature of 773 K, while Cr-doped Cu exhibited an enhancement in rate compared to its normal oxidation in the same temperature range. However, above 873 K, all three systems under shorting circuitry attachment exhibited enhanced rates compared to their normal oxidation rates in conformity to the existing theoretical model. Use of additional resistances in series in the outer short-circuit Pt path have clearly established that below 773 K Mott's fieldinduced migration plays the most important role, while at elevated temperatures Wagner's electrochemical potential-gradient factor acts as the main driving force in the scale-growth process. The results have been interpreted on the basis of average defect concentration, the electrochemical potential gradient, electrical field gradient, and transport coefficient in the Cu2O layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01046885
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