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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Empirica 5 (1978), S. 195-213 
    ISSN: 1573-6911
    Source: Springer Online Journal Archives 1860-2000
    Topics: Economics
    Notes: Summary Capital and labour intensity in Austria's foreign trade is examined on the basis of the 1964 input-output table. Eight variants were calculated in which tourist industry, imported intermediate consumption, and extractive industries, as well as agriculture trade, and transport were variously included and excluded. Calculations are based on domestic capital and labour intensities, as is done in all similar studies. In 1964 capital and labour intensity in Austria's foreign trade was neutral. The inclusion of tourism and of extractive industries, agriculture et al. results in a higher relative capital intensity in Austrian exports. It follows from the calculations that the capital intensity of imports was definitely not higher than that of exports; a certain proponderance of higher imports was identified in the case of human capital.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wird über eine modifizierte Thunberg-Methode berichtet, die es gestattet, die Kinetik von Reaktionen unter anaeroben Bedingungen mit hoher Genauigkeit (Fehler ± 1%) zu verfolgen. Als Anwendungsbeispiel wird die AktivitÄtsbestimmung von Xanthinoxydase mit Xanthin und Methylenblau als Acceptor beschrieben.
    Notes: Summary A modified Thunberg method is proposed allowing the observation of the kinetics of reactions under anaerobic conditions with high accuracy (error ±1%). As an example of application the estimation of the activity of xanthine oxidase acting on xanthine and methylene blue as an acceptor is described.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Copolymerizations of ethylene or propylene with butadiene, 1,5-hexadiene or 1,7-octadiene by MgH2/TiCl4-AlEt3 catalyst system were carried out. The effect of diene concentration in the reaction medium for each polymerization system on catalytic activity was observed. The compositions of the obtained copolymers were evaluated and the reactivity ratios were determined. Ethylene-propylene-diene terpolymerizations with the same catalyst system were also investigated.
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  • 4
    Publication Date: 2014-01-24
    Description: In 339 interviews we identified 449 time related and culturally determined critical incidents. We can clearly distinguish time behaviour of Anglo-German managers from that of managers from France and Italy and East Central Europe. These incidents with East Central European Managers can be grouped in two categories: slow speed of solving tasks and extreme length of negotiations and decision making processes. This time behaviour can be explained by working in collectives and priority setting by supervisors. Risk aversion, harmony seeking, and saving own face are values/culture standards that determine time consuming discussion and decision making behaviour. Wasting time of their (West European) counterparts is of no concern for East Central European Managers, unlike harmony within the collective.
    Description: In 339 Interviews konnten wir 449 zeitbezogene und kulturell determinierte kritische Interaktionssituationen identifizieren. Wir können dabei klar unterscheiden zwischen dem Zeitverhalten englischer/deutscher Manager, dem Verhalten von Managern aus Frankreich und Italien und denen aus Ost- und Mitteleuropa. Diese Situationen mit Managern aus OME können dabei in zwei Kategorien eingeteilt werden: hoher Zeitbedarf bei Problemlösungen und extreme Verzögerungen bei Verhandlungen und Entscheidungsprozessen. Dieses Zeitverhalten kann erklärt werden durch die Arbeitsweise in Kollektiven und die Prioritätensetzung durch den Vorgesetzten. Risikoaversion, Harmoniestreben und Gesichtwahren sind Werte/Kulturstandards die hier zeitaufwändige Diskussionen und Entscheidungsprozeduren beeinflussen. Zeitverschwendung bei ihren (westeuropäischen) Partnern wird von Managern aus OME als nicht so wichtig eingestuft wie die Harmonie im Kollektiv.
    Keywords: ddc:650 ; East Central Europe ; Austria ; international management
    Repository Name: EconStor: OA server of the German National Library of Economics - Leibniz Information Centre for Economics
    Language: English
    Type: doc-type:article
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  • 5
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The determination of active centres concentration in ethylene polymerization using various TiCl4/MgH2-Al(C2H5)3 catalytic systems, by the 14CO radio-tagging method, is reported. It is found that with increasing the absolute titanium amount the concentration of active centres, [C*], increases, whereas the propagation rate constant, kp, decreases. In addition, using various TiCl4/MgH2 catalysts in ethylene polymerization, it is found that the lower the Ti content, the higher is the surface area of the catalyst and the higher is the polymerization activity. Determination of [C*] shows consclusively that the decrease in the polymerization activity observed to occur with increasing the Ti content, and thus decreasing the surface area, is unequivocally due to a reduction in the concentration of active centres but not to any fundamental change in the value of the propagation rate constant.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The syndiotactic propene polymerization was investigated by means of the Cs-symmetric isopropylidene(fluorenyl)(cyclopentadienyl)zirconium dichloride/methylaluminoxane (iPr(Flu)-(Cp)ZrCI2/MAO) catalyst system in toluene/methylene chloride solvent mixtures. The main result is that with increasing dielectric constant of the solvent mixture the polymerization rate increases linearly but the stereospecificity of the catalyst decreases strongly; this is revealed through a drastic decay of the rrrr-pentads and of the melting point of the polymers. Hence, the stereospecificity of this catalyst system is connected with the existence of a polarized Zr-CI-AI-complex (in toluene) or at least of a tight contact ion pair with a stereoregulating role of the counter ion. The loss of the stereospecifity in polar solvents is caused by an isomerization reaction of the solvent-separated free zirconocene species via migration of the growing polymer chain before the next monomer insertion. But in the case of the isotactic catalyst system dimethyl-silyl(bisindenyl)zirconium dichloride/methylaluminoxane (Me2Si(Ind)2ZrCl2/MAO) with a C2-symmetric π-ligand system the migration of the growing polymer chain in polar solvents causes no isomerization.
    Additional Material: 2 Ill.
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  • 7
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The ethylene and propene homopolymerization was investigated by means of the Cs-symmetric [2,4-cyclopentadien-1-ylidene(isopropylidene)fluoren-9-ylidene]zirconium dichloride/methylaluminoxane (iPr[FluCp]ZrCl2/MAO) and the C2-symmetric [(dimethylsilylene)bis(η5-inden-1-ylidene)]zirconium dichloride/methylaluminoxane (Me2Si[Ind]2ZrCl2/MAO) catalyst systems in toluene. Surprisingly, the Cs-symmetric catalyst polymerizes propene faster than ethylene. The main results of the kinetic analysis are a first-order dependence on the concentration of Zr but a bell-shape in the plot of the polymerization rate versus log([Al]: [Zr]). This is true for both catalyst systems. Furthermore with increasing [Al]:[Zr] ratio the fraction of rmrr pentads is decreased continuously with the Cs-symmetric catalyst; in the same direction the molecular weights are decreased. On the contrary with the C2-symmetric catalyst the stereospecificity and the molecular weights remain constant. The kinetic results reflect the complex role of the MAO, i.e. the existence of sterically more and more tight contact species between metallocene and MAO components with increasing [Al]: [Zr] ratio. The different behaviour of the two catalyst systems concerning stereospecificity and molecular weights of the polymers are due to different symmetry and different size of the angle between the planes of the π-ligand systems.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The stereorigid ansa-metallocene catalysts [2,4-cyclopentadien-1-ylidene(isopropylidene)-fluoren-9-ylidene]zirconium dichloride/methylaluminoxane (iPr[FluCp]ZrCl2/MAO) and [(dimethylsilylene)bis(η5-inden-1-ylidene)]zirconium dichloride/methylaluminoxane (Me2Si[Ind]2-ZrCl2/MAO) are different in respect to the symmetry and, therefore, to the behaviour of the stereospecifity, in the size of the angle between the planes of the π-ligand systems and in the homopolymerization behaviour of ethylene and propene. The present paper concerns itself with comparing the investigations of the ethylene/α-olefin and the ethylene/cycloolefin copolymerization with both catalyst systems. The main kinetic result for both catalysts is that the α-olefins show an accelerating effect on the ethylene polymerization rate during the copolymerization whereas norbornene shows exclusively a rate-decreasing effect. The acceleration effect can be explained by an increase in the concentration of active centres and/or an increase of the rate constant of the ethylene insertion. The analysis of the microstructures of the formed copolymers by the use of statistical models demonstrates that in copolymers with a high content of α-olefins, the experimental trial distributions can only be described satisfactorily with second-order Markovian statistics. That means that in this case the last two monomers have influence on the insertion of the subsequent monomer. A further main result of all investigated copolymerizations is that the r-parameters for the α-olefin insertion are more favourable for the system iPr[FluCp]ZrCl2/MAO than for the system Me2Si[Ind]2ZrCl2/MAO; the reason for this is the different size in the coordination gap aperture of the π-ligands. Furthermore, the r-parameters show only a small dependence on the chain length of the α-olefin. Finally, it is remarkable that the stereospecifity (syndiotactic or isotactic α-olefin blocks) remains intact in the copolymers.
    Additional Material: 10 Ill.
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  • 9
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: This paper deals with the kinetics of the polymerization of ethylene catalysed by the soluble Ziegler-catalyst Cp2TiPropylCl/AlEtCl2. By means of a special method it was possible to study the kinetics of the initial instationary homogeneous part of the polymerization. The dependences of the initial rates on the catalyst components prove that the polymerization active species is formed in two successive very dynamic equilibria. The primary complex equilibrium is entirely located on the right hand side, whereas the second equilibrium depends considerably on the ratio of the catalyst components and is shifted on the active species side only at very high Al/Ti ratios. Because of this location of the two successive equilibria the dependence of the polymerization velocity vp on the charged Al concentration (that is, the Al isotherm) has to show a sigmoidal curve course in the inital part, which experimentally is confirmed exactly. Finally, this extensive kinetical analysis leads to the complete reaction scheme of the polyreaction and by mathematical modelling to the quantitative calculation and description of the experimental curves and dependences (e.g., Al-isotherm).
    Additional Material: 10 Ill.
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  • 10
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Determination of active centres using TiCl4/MgH2-supported catalyst system in ethylene polymerization is reported. A radio-tagging technique, whereby 14CO is used to label the polymerization active centres, is employed. Optimization of the 14CO/Ti ratio showed that the polymer radioactivity remained constant after a 14CO/Ti ratio of about 8 was attained. At the optimal 14CO/Ti ratio, it is found that up to 14% of the titanium on the catalyst surface are active in polymerizations at 40°C, 10 min reaction time, and 30 min contact time period of 14CO with the polymerization medium. Moreover, the value of the corresponding propagation rate constant, Kp, was found to be about 230 dm3/(mol·s).
    Additional Material: 6 Ill.
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