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  • 1
    Electronic Resource
    Electronic Resource
    On theR-order of coupled sequences arising in single-step type methods (1988)
    Springer
    Numerische Mathematik 53 (1988), S. 653-661 
    Details
    ISSN: 0945-3245
    Keywords: AMS(MOS): 65H10 ; 15A48 ; CR: G1.5
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary As shown in preceding papers of the authors, the verification of anR-convergence order τ for sequences coupled by a system (1.1) of basic inequalities can be reduced to the positive solvability of system (3.3) of linear inequalities. Further, the bestR-order $$\bar \tau$$ implied by (1.1) is equal to the minimal spectral radius of certain matrices composed from the exponents occuring in (1.1). Now, these results are proven in a unified and essentially simpler way. Moreover, they are somewhat extended in order to facilitate applications to concrete methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01397134
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  • 2
    Electronic Resource
    Electronic Resource
    On the R-order of coupled sequences III (1983)
    Springer
    Computing 30 (1983), S. 157-169 
    Details
    ISSN: 1436-5057
    Keywords: 65H10 ; 15A48 ; Iterative parallel processes ; best individualR-orders ; ordered positive decomposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Für konvergente Folgen {x n,1 },...,{x n,s }, welche über ein System (2) von Ungleichungen miteinander verkoppelt sind, werden die besten individuellenR-Ordnungen τ1,...,τ s bestimmt. Dazu wird gezeigt, daß diese gleich den Spektralradien von bestimmten Matrizen sind, welche aus Exponenten in (2) gebildet werden.
    Notes: Abstract For convergent sequences {x n,1 },...{x n,s } coupled by a system (2) of inequalities the optimal individualR-orders τ1,...,τ s are determined as the spectral radii of certain matrices composed of exponents appearing in (2).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02280786
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  • 3
    Electronic Resource
    Electronic Resource
    Determination of the cone radius for positive concave operators (1984)
    Springer
    Computing 33 (1984), S. 37-49 
    Details
    ISSN: 1436-5057
    Keywords: 65H10 ; 90C30 ; 15A48 ; Iterative processes ; bestR-orders ; cone radius of concave operators ; spectral radii ; partial ordering
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Description / Table of Contents: Zusammenfassung Die Berechnung der bestenR-Ordnung von Folgen aus iterativen Näherungsverfahren führt auf die Ermittlung des hier eingeführten Kegelradius bestimmter konkaver Operatoren. Das Hauptergebnis der Arbeit ist die Darstellung des Kegelradius als Infimum der Spektralradien aller den konkaven Operator majorisierenden linearen Operatoren. Diese Charakterisierung ist von numerischem Intersse.
    Notes: Abstract The computation of bestR-orders of sequences produced by iterative methods leads to the determination of the cone radius of certain concave operators. The main result of the paper is the representation of the cone radius as the infimum of spectral radii of all linear operators majorizing the concave operator. This characterization is of numerical interest.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02243074
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  • 4
    Electronic Resource
    Electronic Resource
    Chemistry of male mandibular gland secretions ofPhilanthus triangulum (1990)
    Springer
    Journal of chemical ecology 16 (1990), S. 2135-2143 
    Details
    ISSN: 1573-1561
    Keywords: Philanthus triangulum ; Hymenoptera ; Sphecidae ; Philanthinae ; beewolf ; (Z)-11-eicosen-1-ol ; 10-nonadecen-2-one ; nonadecenal ; eicosenal ; pheromone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Males of the European and African beewolf,Philanthus triangulum, possess a sex specific mandibular gland secretion that is used for marking plant stems in mating territories. The secretion is composed of 90% (Z)-11-eicosen-1-ol plus small amounts of 10-nonadecen-2-one, nonadecenal, octadecanoic and octadecenoic acids, and eicosenal. The chemistry of this secretion differs markedly from the secretions of North AmericanPhilanthus, which consist of a larger number of components that possess different chemical functionalities and are more volatile. We postulate that the chemical differences betweenP. triangulum and its New World relatives reflect phylogenetic differences plus a possible reduced necessity for species isolating mechanisms inP. triangulum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01026925
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  • 5
    Electronic Resource
    Electronic Resource
    Mandibular gland secretions of the male beewolvesPhilanthus crabroniformis, P. barbatus, andP. pulcher (Hymenoptera: Sphecidae) (1992)
    Springer
    Journal of chemical ecology 18 (1992), S. 27-37 
    Details
    ISSN: 1573-1561
    Keywords: Philanthus crabroniformis ; Philanthus barbatus ; Philanthus pulcher ; Hymenoptera ; Sphecidae ; beewolf ; mandibular glands ; pheromones ; semiochemicals ; mass spectrometry ; infrared spectroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The composition of the territorial marking pheromones from mandibular glands of males of the beewolvesPhilanthus crabroniformis, P. barbatus, andP. pulcher have been determined. The structures of the components were elucidated by gas chromatography-mass spectrometry and gas chromatography-Fourier transform infrared spectroscopy. The major compound ofP. crabroniformis is isopropyl tetradecanoate, with somewhat lesser amounts of 2-tridecanone, 3-methyl-3-butenyl tetradecanoate, and 92∶8 (Z)∶(E)-11-eicosen-1-ol. The major compounds ofP. barbatus are ethyl tetradecanoate and hexadecanal, which are present in approximately a 60∶40 ratio. These two compounds comprise over 95% of the neutral lipids. Also present in lesser amounts are ethyl dodecanoate, tetradecanal, hexadecan-1-ol, a Δ x -octadecen-1-ol, and octadecan-1-ol. The major compounds ofP. pulcher are ethyl (Z)-7-hexadecenoate and geranylgeraniol acetate, which comprise nearly 90% of the neutral lipid fraction, with smaller amounts of tetradecanal, pentadecanal, and ethyl hexadecanoate; trace amounts of Δ x hexadecenal, hexadecanal, and octadecanal are also present.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00997162
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  • 6
    Electronic Resource
    Electronic Resource
    Volatiles from mandibular glands of male beewolves (Hymenoptera: Sphecidae,Philanthus) and their possible roles (1985)
    Springer
    Journal of chemical ecology 11 (1985), S. 895-901 
    Details
    ISSN: 1573-1561
    Keywords: Philantus ; beewolf ; Sphecidae ; Hymenoptera ; pheromones ; scentmarking ; tridecanone ; pentadecanone ; heptadecanone ; hexadecanoic acid ; ethyl hexadecanoate ; octadecanoic acid ; ethyl octadecanoate ; mandibular glands ; wasps
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Observations of wasp behavior indicate that male beewolves,Philanthus basilaris andP. bicinctus apply a “marking pheromone” to the leaves and stems of plants within their territories. We now provide direct evidence for the presence of volatile chemicals in the paired mandibular glands of the males, provide preliminary identification of these volatiles, and show that all of the volatile chemicals in the mandibular glands are present on freshly marked plant surfaces but are absent from unmarked plants. Pyrazines, which have been reported in other species of aculeate wasps including the EuropeanPhilanthus triangulum, were not found inP. basilaris orP. bicinctus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01012076
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  • 7
    Electronic Resource
    Electronic Resource
    Massenspektroskopische Untersuchungen positiver und negativer lonen von 3,5-disubstituierten 1,2,4-Thiadiazolen (1985)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 327 (1985), S. 1017-1022 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Comparative Positive and Negative Ion Mass Spectroscopy of 3,5-Disubstituted 1,2,4-Thiadiazoles
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19853270621
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  • 8
    Electronic Resource
    Electronic Resource
    On the factors governing the pressure dependence of the viscosity of moderately concentrated polymer solutionsPart of theses of H. G. and J. R. S. (1982)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 27 (1982), S. 1277-1291 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Viscosity measurements were carried out as a function of pressure and temperature with solutions of polystyrene in eight (endothermal) θ-solvents at the respective critical composition by means of a Searle-type apparatus. A rolling-ball viscometer was used for the investigation of the pure solvents. In all cases the viscosity coefficient increases in a more or less exponential manner when the pressure is raised. For θ-conditions, the volumes of activation of the solutions exceed that of the pure solvent by typically 10-15%. The exact amount of this extra efffect stemming from the presence of the polymer and its variation with temperature can be qualitatively correlated with the heats of mixing. The ratio of the viscosity of the solution at 1000 and 1 bar, respectively, can be varied for a given solvent power (θ-temperature) by the choice of the solvent from ca. 2 (cyclopentane) to 4 (trans-decalin). Within a given system, the maximum effects that can be realized by a change of the solvent power via the variation of temperature ranges from ca. 3 to 6 (tert-butylacetate).
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1982.070270417
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  • 9
    Electronic Resource
    Electronic Resource
    Chemistry of male mandibular gland secretions ofPhilanthus basilaris cresson andPhilanthus bicinctus (Mickel) (Hymenoptera: Sphecidae) (1987)
    Springer
    Journal of chemical ecology 13 (1987), S. 227-235 
    Details
    ISSN: 1573-1561
    Keywords: Philanthus ; Hymenoptera ; Sphecidae ; pheromone ; scent-marking ; 2-alkanones ; fatty acids ; ethyl esters ; alkenals ; N,N-dimethylhy-drazine ; methyl esters ; EI-MS ; CI-MS ; methoxymercuration ; methylthiolation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Detailed chemical characterizations are provided for the species-specific mixtures of marking pheromones utilized by the male beewolvesPhilanthus basilaris andP. bicinctus. Successful analysis of these complex mixtures of 2-ketones, fatty acids, ethyl esters, and aldehydes was facilitated by the treatment of the crude extracts with 1,1-dimethylhydrazine and direct analysis of the resulting hydrazones, methyl esters, and starting ethyl esters by GC-MS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01025883
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  • 10
    Electronic Resource
    Electronic Resource
    Use of adiabatic experiments for kinetic studies in fixed catalyst beds (1964)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 10 (1964), S. 149-154 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A method is presented for using an adiabatic reactor to study the kinetics of reactions of gases on solid catalysts. The method is based on measurement of the steady state axial profile of temperature or composition in a specially designed adiabatic packed bed reactor. Reaction rates are calculated from these measured profiles by graphical differentitation. The method is applicable for multireaction systems and for any type of kinetic behavior.The method was demonstrated by an experimental study of cumene cracking an silica-alumina catalyst at 420° to 480°C. The measured reaction rates are in satisfactory agreement with results obtained by other investigators who used isothermal reactors. Areas of application of the adiabatic method are suggested.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690100205
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