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  • 1
    facet.materialart.
    Unknown
    Rodrigo de Oviedo, iluminador ignorado (1973)
    Madrid : Periodicals Archive Online (PAO)
    Archivo español de arte. 46:182 (1973:abr./jun.) 192 
    Details
    ISSN: 0004-0428
    Topics: Art History
    Notes: VARIA
    URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pao:&rft_dat=xri:pao:article:5377-1973-046-82-000010
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  • 2
    Electronic Resource
    Electronic Resource
    Tolypocladin — a new metal-chelating 2-aza-anthraquinone fromTolypocladium inflatum (1990)
    Springer
    BioMetals 3 (1990), S. 39-44 
    Details
    ISSN: 1572-8773
    Keywords: Tolypocladin ; New 2-aza-anthraquinone ; Metal-chelating properties ; Metabolite ofTolypocladium inflatum ; Regulation of production by zinc ions ; Role as endogenous electron acceptor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary A new chelator of di- and trivalent cations (tolypocladin) was isolated from the mycelium ofTolypocladium inflatum DSM 915. The structure has been determined by NMR methods as 3-methyl-5,6(7),8-trihydroxy-2-aza-anthraquinone. The ultraviolet, visible and fluorescence spectral properties of some metal complexes (in methanol) are described. The compound forms water-soluble fluorescent aluminium complexes. Its production is dependent on zinc ions in the medium. It serves as an endogenous hydrogen acceptor under oxygen limitation in the producing strain,T. inflatum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01141176
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  • 3
    Electronic Resource
    Electronic Resource
    Cenozoic Intraplate Alkaline Volcanism of Western Bohemia (2000)
    Springer
    Studia geophysica et geodaetica 44 (2000), S. 346-351 
    Details
    ISSN: 1573-1626
    Keywords: Western Bohemia ; alkaline volcanism ; Ohře Rift ; Cheb-Domažlice Graben ; tectonics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences , Physics
    Notes: Abstract Three independent volcanic suites have been recognised in W Bohemia: (i) the old unimodal alkaline ol. nephelinite-tephrite (29-19 Ma) in the Ohře Rift, (ii) two contemporaneous weakly (trachybasalt/trachyandesite-trachyte/rhyolite; 13-11 Ma) and strongly (ol. nephelinite-tephrite/basanite; 12-8 Ma) alkaline series in the flank of the Cheb-Domažlice Graben formed by the Teplá Highland and (iii) the young unimodal ol. melilitite/ol. nephelinite alkaline suite (2.0-0.12 Ma) at the intersection of the above mentioned structures in the Cheb Basin. The magmas of all the suites are mantle-derived and, in the case of the Cheb-Domažlice Graben series, associated with the AFC process. Two main fault systems: (i) ENE-WSW and (ii) NNW-SSE are developed in W Bohemia, corresponding to the directions of the two prominent taphrogenic structures. The southwesterly continuation of the Ohře Rift across the Mariánské Lázně Fault is marked by volcanics only.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022131413783
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  • 4
    Electronic Resource
    Electronic Resource
    Reaction of epichlorohydrin with methanol investigated by gel chromatography (1977)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 64 (1977), S. 187-196 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Produkte der Additionsreaktion von Epichlorhydrin mit Methanol wurden mit Hilfe der gelchromatographischen Methode studiert. Die festgestellten Werte ermöglichten es, eine Beziehung zwischen den Reaktionsgeschwindigkeiten der Initiierung und der Wachstumsreaktion aufzustellen. Die mit Hilfe des mathematischen Modells für die ersten sechs Wachstumsschritte, K1 bis K6 = 0,2 - 0,15 - 0,1 - 0,08 - 0,07 - 0,06, berechneten Werte stimmen am besten mit den experimentellen Ergebnissen überein.
    Notes: Products of the addition reaction between epichlorohydrin and methanol were studied by the method of gel chromatography. Data thus determined allowed to obtain a more precise relationship between the reaction rates of initiation and propagation. The K values of the first propagation steps calculated by using a mathematical model, K1 to K6 = 0.2 - 0.15 - 0.1 - 0.08 - 0.07 - 0.06 are closest to the experimental results.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1977.050640117
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  • 5
    Electronic Resource
    Electronic Resource
    Mathematical model of polyaddition of 1-chloro-2,3-epoxypropane to α, ω-diolsPartly presented at the “IUPAC International Symposium on Macromolecules”, July 2-8, 1972, Helsinki. (1973)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 168 (1973), S. 131-143 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Ein mathematisches Modell für die Zusammensetzung der Polyadditionsprodukte aus 1-Chlor-2,3-epoxypropan und Äthylenglykol wurde unter der Annahme aufgestellt, daß die Hydroxy-Reaktivität aller 3-Chlor-2-hydroxypropyloxy-Endgruppen identisch ist, daß auch alle restlichen Hydroxylgruppen der Diolmoleküle gleiche Reaktivitäten aufweisen und daß die Oxiranringe sich ausschließlich unter Bildung der cα-Äther öffnen. Durch Vergleich von berechnetem und experimentell gewonnenem Prozentgehalt an unumgesetztem Äthylenglykol (für verschieden gewählte kinetische Parameter), konnten bei verschiedenen Anfangs-Molverhältnissen im Augenblick des Gesamtumsatzes von 1-Chlor-2,3-epoxypropan die Reaktivitätsverhältnisse der drei Hydroxylgruppen bestimmt werden. Das Verhältnis der Geschwindigkeitskonstanten von sek. Hydroxyl der 3-Chlor-2-hydroxypropyloxy-Endgruppe und initiierendem Äthylenglykolhydroxyl beträgt 0,6; dasjenige von restlichem Hydroxyl des Glykols und initiierendem Äthylenglykolhydroxyl beträgt 0,5.
    Notes: A mathematical model for the composition of products resulting from a polyaddition of 1-chloro-2,3-epoxypropane to ethylene glycol was constructed on the presumption that the reactivites of the 3-chloro-2-hydroxypropyloxy end groups are equal, that the remaining hydroxyl groups have also identical reactivities, and that the oxirane ring opens to give exclusively Cα-ethers. By comparing the calculated and experimentally obtained percentage of unreacted ethylene glycol (for various chosen kinetic parameters) at variable initial mole ratios in the moment of complete conversion of 1-chloro-2,3-epoxypropane, the relative reactivities of all three hydroxyl groups could be determined. The reactivity ratio of the hydroxyl group in the 3-chloro-2-hydroxypropyloxy end group to the initial hydroxyl group in the diol was found to be 0,6 and that of the remaining diol group to the initial diol group to be 0,5.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1973.021680113
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  • 6
    Electronic Resource
    Electronic Resource
    Die kinetik der polyadditionsreaktionen des 1-chlor-2,3-epoxypropans (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 3161-3171 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: A new method for the evaluation of concentration/time data from kinetic investigations of the polyaddition of 1-chloro-2,3-epoxypropane (epichlorohydrin) is proposed. The method enables to calculate not only the rate constant of initiation but also the rate constant of propagation (if the rate constants of the individual propagation steps are equal or at least close to each other).
    Notes: Es wird eine neue Methode zur Auswertung der Abhängigkeit des Verhältnisses Konzentration/Zeit bei der kinetischen Untersuchung der Polyaddition von 1-Chlor-2,3-epoxypropan (Epichlorhydrin) vorgeschlagen, die es erlaubt, neben der Geschwindigkeitskonstante der Initiierungsreaktion auch die Geschwindigkeitskonstante des Wachstums zu berechnen (gleiche oder wenigstens naheliegende Geschwindigkeitskonstanten der einzelnen Wachstumsstufen vorausgesetzt).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021751110
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  • 7
    Electronic Resource
    Electronic Resource
    Einfluß von inhibitoren auf die lagerfähigkeit von ungesättigten polyesterharzen (1984)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 128 (1984), S. 123-132 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In this paper the effect of seven inhibitors on the storage stability of unsaturated polyesters is compared by means of an accelerated storage-life test. The shelf life of polyesters was predicted for different temperatures with various amounts of inhibitors. We found that the mechanism of reaction did not change in the temperature range of 23-120°C, but some inhibitors showed different activation energies. The results of the measurements were explained in the equation connecting shelf life with temperature and inhibitor concentration. If the inhibition effect of different inhibitors shall be considered, temperature and inhibitor concentration have to be taken into account.
    Notes: In der vorliegenden Arbeit werden mit Hilfe eines beschleunigten Lagerzeittests die Einflüsse von sieben verschiedenen Inhibitoren auf die Lagerungsfähigkeit von ungesättigten Polyesterharzen verglichen. Es wurde die Lagerzeit von Harzen mit unterschiedlichen Inhibitorgehalten bei verschiedenen Temperaturen verfolgt. Es wurde festgestellt, daß die Reaktionen im untersuchten Temperaturbereich (23 - 120°C) nach dem gleichen Mechanismus, aber für manche Inhibitoren mit unterschiedlicher Aktivierungsenergie verlaufen. Aus den Meßergebnissen wurden mathematische Gleichungen hergeleitet, welche die Abhängigkeit der Lagerzeit von Temperatur und Inhibitorkonzentration ausdrücken. Aus der vorgelegten Arbeit geht hervor, daß beim Vergleich der Wirksamkeit von Inhibitoren außer der Temperatur auch die Inhibitorkonzentration in Betracht gezogen werden muß
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1984.051280106
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  • 8
    Electronic Resource
    Electronic Resource
    Polarographisches Studium von Inhibitorgehaltsänderungen in ungesättigten Polyesterharzen bei radikalischer Aushärtung (1984)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 126 (1984), S. 27-37 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In this paper is described the behaviour of hydroquinone and 1,4-benzoquinone during radical curing of unsaturated polyester resins. Polarographic studies of concentration changes of inhibitors supplied with measuring of viscosity of resins proved different behaviour of hydroquinone and 1,4-benzoquinone. About hydroquinone it is supposed it reaction with primary radicals to result 1,4-benzoquinone, which is afterwards reacting with growing radicals. It was found by polarographic studies, that with both, hydroquinone and 1,4-benzoquinone, the polymerization begins already in presence of a certain amount of inhibitor.
    Notes: In dieser Arbeit wird das Verhalten von Hydrochinon und 1,4-Benzochinon bei radikalischer Aushärtung von ungesättigten Polyesterharzen beschrieben. Polarographische Untersuchungen über Änderungen der Inhibitorkonzentrationen, ergänzt durch Viskositätsmessungen von Harzen, haben ein abweichendes Verhalten von Hydrochinon und 1,4-Benzochinon erwiesen. Bei Hydrochinon setzt man seine Reaktion mit Primärradikalen unter Entstehung von 1,4-Benzochinon voraus, welches dann weiter mit wachsenden Radikalen reagiert. Durch polarographische Untersuchungen wurde festgestellt, daß es sowohl bei Hydrochinon als auch bei 1,4-Benzochinon schon während der Anwesenheit von Inhibitor zur Polymerisation kommt.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1984.051260104
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  • 9
    Electronic Resource
    Electronic Resource
    The kinetics reaction of 1-chloro-2,3-epoxypropane with n-butyl and iso-butyl alcohols (1973)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 5 (1973), S. 919-927 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reactions of 1-chloro-2,3-epoxypropane with n-butyl and isobutyl alcohols and their 3-chloro-2-hydroxypropyl ethers, respectively, in the presence of boron fluoride diethyl etherate catalyst are of the first order with regard to 1-chloro-2,3-epoxypropane as well as to the catalyst. In the catalyst concentration range of 1.4 to 47.3 mmol/l., the participation of the catalyst in the reaction is incomplete. The mechanism of the reactions resembles SN2 in regard to changes of activation entropy and influence of dielectric constant of the reaction medium upon the reaction rate. The established values of K (the ratio of propagation to initiation rates) are suitable for calculating the compositions of the adducts obtained. The experimentally obtained yields of 3-chloro-2-hydroxypropyl ethers of lower alcohols are compared with those calculated from the kinetically determined values of K.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550050603
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