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
  • 1
    ISSN: 1359-5997
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying
    Notes: Abstract A procedure to estimate the failure probabilities of reinforced concrete (R/C) chimneys under severe wind loading which allows for considering realistic correlation values of concrete strength is developed. The results show that the assumption of full correlation of concrete strength within cross-sections, as suggested for example in present codes, may significantly overestimate the failure rates in present examples by two orders of magnitude. However, it is also shown that not only one but a number of cross-sections may contribute to the total failure rate of R/C chimneys. As a consequence, the failure estimates increase, in some cases by as much as two orders of magnitude. In the numerical examples as investigated here these counteracting effects neutralize each other. This fact, however, should not be generalized.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Contributions to mineralogy and petrology 6 (1958), S. 112-138 
    ISSN: 1432-0967
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Zusammenfassung In der vorliegenden Arbeit wurde erneut die Frage nach dem Zusammenhang zwischen der Farbe der Natriumeisenpyroxene und ihrer chemischen Konstitution aufgeworfen. Da die früheren Versuche, diese Frage auf analytischem Wege zu lösen, nicht zum Ziele geführt hatten, wurde hier das reine Endglied NaFeIIIISi2O6 synthetisch hergestellt; in weiteren Versuchen wurden Na und Fe3+ durch andere Ionen zu einem kleinen Teil ersetzt und der Einfluß auf die Farbe ermittelt Es wurden Versuche durchgeführt, bei denen Na durch Ca oder Cd, Fe3+ durch Mg, Mn2+, Fe2+, Co, Ni oder Zn ersetzt wurde; bei weiteren Versuchen wurde anstelle von Fe3+ zu einem kleinen Teil sowohl eines der obengenannten 2wertigen Ionen als auch Ti4+ oder Zr4+ eingebaut. Die erhaltenen Mischkristalle wurden optisch und röntgenographisch untersucht. Zur näheren Charakterisierung dieser Mischglieder wurde in einer Reihe von Schliffen das Absorptionsspektrum in verschiedenen kristallographischen Richtungen bestimmt und mit den ebenfalls aufgenommenen Absorptionskurven von natürlichen Ägirinen verglichen. Auf Grund der synthetischen Versuche werden folgende Definitionen vorgeschlagen: Die Namen Akmit und Ägirin sollen weiterhin für Natriumeisenpyroxen nebeneinander beibehalten werden, wobei die Abgrenzung gegenüber Ägirinaugit gemäß dem Vorschlag vonTröger (2) vorgenommen werden kann. Für die Unterscheidung der beiden Varietäten soll gemäß den bisherigen Gepflogenheiten die Farbe maßgebend sein. Das reine Endglied NaFeIIISi2O6 ist braun und muß deshalb als Akmit bezeichnet werden. Ferner sind mit Akmit die Mischkristalle zu bezeichnen, bei denen das Fe3+ durch Mn ersetzt ist, da auch diese Glieder braune Farbe aufweisen; die Ansicht vonGrout konnte also durch synthetische Versuche bestätigt werden. Die grüne Farbe der Ägirine in RichtungX undY wird durch die gleichzeitige Anwesenheit von 2- und 3wertigem Eisen hervorgerufen, so daß als Ägirin diejenigen Mischkristalle zu bezeichnen sind, bei denen 3wertiges Eisen durch zwertiges ersetzt ist. Der Einfluß des 2wertigen Eisens überwiegt dabei gegenüber dem Einfluß anderer Ionen. Das häufigere Auftreten des Ägirin gegenüber Akmit hat also seine Ursache darin, daß in der Natur 2wertiges Eisen praktisch stets vorhanden ist. Die Gitterkonstanten von Akmit und Ägirin sind im Bereich der hier erzielten Meßgenauigkeit gleich und wurden wie folgt bestimmt:a = 9,66 Åb = 879 Åc = 5,26 Åβ = 72,7 ° Die Arbeit wurde gefördert durch eine Spende keramischen Materials zum Bau der Versuchsöfen, wofür ich auch an dieser Stelle der Fa. Stemag in Lauf meinen Dank aussprechen möchte. Der Fa. Elchem in Nürnberg danke ich für die Durchführung der Spektralanalysen sowie für die Anfertigung einer Aufnahme mit der Guinier-Kammer. Ferner danke ich dem Institut für Anorganische Chemie der Universität Erlangen für Überlassung, bzw. Anfertigung einiger Substanzen.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 113 (1982), S. 1079-1085 
    ISSN: 1434-4475
    Keywords: Aluminium ; Crystal Structure ; Iron ; Oxygen ; Rare Earth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract New compounds of magnetoplumbite structure with rare earth-ions were prepared by solid state reactions and determined by X-ray single crystal work. They crystallize in space group D 6h 4 -P63/mmc withA:a=582.6,c=2283;B:a=563.4,c=2208;C:a=565.8,c=2218 pm. The distribution of Fe and Al to the metal positions were determined and the thermal ellipsoids of the metal positions are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Microchimica acta 44 (1956), S. 393-400 
    ISSN: 1436-5073
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary A method is described for determining the trace elements in soils, plants, feeds, and fertilizers. The trace elements are separated from the major constituents and concentrated by shaking with complex-forming compounds, after destroying the organic material, the concentrate obtained is dissolved in acid. These solutions are brought continuously on a disk of spectrum carbon and simultaneously spectrographed in sparks. The evaluation is made by comparison with solutions of known content in the usual manner.
    Abstract: Résumé Description d'une méthode de dosage des oligoéléments dans les sols, les plantes, la nourriture et les engrais. Les éléments sont séparés de la matière à analyser, concentrés par agitation avec des substances complexantes. Après destruction de la matière organique les concentrés obtenus sont dissouts dans un acide. Ces solutions sont amenées de façon continue sur un disque en carbone pur et analysées par spectrographie d'étincelles. La détermination se fait par comparaison avec des solutions étalons suivant la méthode classique.
    Notes: Zusammenfassung Es wird eine Methode zur Bestimmung der Spurenelemente in Böden, Pflanzen, Futter- und Düngemitteln beschrieben. Die Spurenelemente werden von den Hauptbestandteilen getrennt, durch Ausschüttelung mit komplexbildenden Verbindungen angereichert, nach Zerstörung der organischen Substanz die erhaltenen Konzentrate in Säure gelöst. Diese Lösungen werden auf einer Scheibe aus spektralreiner Kohle kontinuierlich aufgebracht und gleichzeitig im Funken spektrographiert. Die Auswertung erfolgt durch Vergleich mit Lösungen bekannten Gehaltes in üblicher Weise.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    International journal of infrared and millimeter waves 6 (1985), S. 459-470 
    ISSN: 1572-9559
    Keywords: high-power millimeter waves ; gyrotron ; electron cyclotron resonance heating (ECRH) ; overmoded waveguide systems ; mode conversion ; linearly polarized narrow pencil beam
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract This work reports calculations and measurements on mode converters for the transformation of TEOn gyrotron mode mixtures (primarily TEO2) into the linearly polarized HE11 hybrid mode at 70 GHz. This mode is ideal for quasi-optical launching systems for ECRH of plasmas. Mode transducers with axisymmetric radius perturbations convert the gyrotron TEOn mode composition into the TEO1 mode. Proper matching of the phase differences between the various modes and of the perturbation amplitudes of the several converter sections is required. The TEO1 wave is used for long-distance transmission through smooth-walled overmoded waveguides. A mode converter with constant diameter and periodically perturbed curvature transfers the unpolarized TEO1 mode into the polarized TE11 wave. The experimentally determined ΣTEOn-to-TEO1 conversion efficiency is (98.5±1)% (99% predicted) while the TEO1-to-TE11 transformer has a (94±2)% efficiency (93% theoretically); ohmic losses are included. The “Gaussian-like” HE11 mode with axisymmetric power distribution and almost no cross polarization is produced in a circumferentially corrugated TE11-to-HE11 mode transducer with a measured conversion efficiency of (98.3±1.5)% (98.5% predicted). The overall efficiency of the complete mode converter system in the desired mode was determined to be (91±2.5)%. High-power operation (200kW, 100ms) has been successfully demonstrated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Molecular and cellular biochemistry 64 (1984), S. 89-95 
    ISSN: 1573-4919
    Keywords: ethanol ; plasma membranes ; phospholipid (rat liver) ; miocroviscosity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary Male Wistar rats were maintained for 35–40 days on a liquid diet containing 36% of calories as ethanol. Ethanol was replaced by carbohydrates in the isocaloric diet fed to control animals. The effect of ethanol consumption has been studied on the fluorescence polarization of rat liver plasma membranes and artificial lipid vesicles and on the lipid composition of the membranes. Fluorescence polarization in both membranes and vesicles was determined using DPH and TMA-DPH as fluorescence markers; from these data, the polarization term (ro/r−1)−1 and flow activation energy (ΔE) were calculated. The ethanol consumption induces a more fluid environment within the membrane core of liver plasma membranes; the ethanol-fed rat membranes are more resistant to the in vitro effect of ethanol disordering the membrane structure. Vesicles obtained with lipids from either control membranes or ethanol-fed rat membranes were treated with ethanol and the changes in polarization paralleled to those exhibited by the membranes. The absence of phase transitions and of ΔE changes was also shown in temperature-dependence studies. The lower cholesterol content found in ethanol-fed rat plasma membranes might be responsible for observed variations in the microviscosity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1617-4623
    Keywords: GC clusters ; Mobile elements ; Target sites ; mtDNA ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary GC clusters constitute the major repetitive elements in the mitochondrial (mt) genome of the yeast Saccharomyces cerevisiae. Many of these clusters are optional and thus contribute much to the polymorphism of yeast mtDNAs. We have made a systematic search for polymorphic sites by comparing mtDNA sequences of various yeast strains. Most of the 26 di- or polymorphic sites found differ by the presence or absence of a GC cluster of the majority class, here referred to as the M class, which terminate with an AGGAG motif. Comparison of sequences with and without the GC clusters reveal that elements of the subclasses M1 and M2 are inserted 3′ to a TAG, flanked by A+T rich sequences. M3 elements, in contrast, only occur in tandem arrays of two to four GC clusters; they are consistently inserted 3′ to the AGGAG terminal sequence of a preexisting cluster. The TAG or the terminal AGGAG, therefore, are regarded as being part of the target sites for M1 and M2 or M3 elements, respectively. The dinucleotide AG is in common to both target sites; it also occurs at the 3′ terminus (AGGAG). This suggests its duplication during GC cluster insertion. This notion is supported by the observation that GC clusters of the minor classes G and V similarily repeat at their 3′ terminus a GT or an AA dinucleotide, respectively, from their putative target sites.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1617-4623
    Keywords: Glucose repression ; Glucose derepression ; Regulatory genes ; Expression analysis ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Yeast strains carrying one of the two regulatory mutations cat1 and cat3 are defectve in derepression of several glucose-repressible enzymes that are necessary for utilizing non-fermentable carbon sources. Hence, these strains fail to grow on ethanol, glycerol or acetate. The synthesis of isocitrate lyase, malate synthase, malate dehydrogenase and fructose-1,6-bisphosphatase is strongly affected in cat1 and cat3 strains. Genes CAT1 and CAT3 have been isolated by complementation of the cognate, mutations after transformation with an episomal plasmid gene library. The restriction map of CAT1 proved its allelism to the earlier isolated SNF1 gene. Both genes appear to exist as single-copy genes per haploid genome as indicated by Southern hybridization. Northern analysis has shown that the 1.35 kb CAT3 mRNA is constitutively expressed, independent of the carbon source in the medium. Derepression studies with CAT3 transformants using a multi-copy plasmid showed over-expression of glyoxylate cycle enzymes. This result would be consistent with a direct effector function for the CAT3 gene product.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 1982-03-01
    Print ISSN: 0236-5731
    Electronic ISSN: 1588-2780
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Published by Springer
    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...