ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
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
    Electronic Resource
    Electronic Resource
    Comparative study of the potentiodynamic behaviour of aluminium at low potentials in barrier layer and in pore-forming electrolytes (1987)
    Springer
    Journal of applied electrochemistry 17 (1987), S. 104-112 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The potentiodynamic behaviour of a 99.9995% aluminium electrode in several barrier layer and pore-forming electrolytes at a temperature of 25° C, with sweep rates in the range 1–200 mV s−1 and potentials between −2.00 and 3.00 V (versus SCE), has been studied. In the anodic sweep the potential of zero current,V j=0, depends on the pH of the electrolyte and corresponds to a corrosion potential (the cathodic and anodic reactions coexist). In the 0.5 M H3BO3-borax solution (pH=6.3) and afterV j=0, the current density increases in a convex form, approaching a steady-state value. For this electrolyte and the potential ranges studied, the anodic charges corresponding to the anodic sweep are independent of the sweep rate and are associated with the formation of a barrier layer oxide. In the neutral 0.50 M propanedioic acid solution (pH=7.0) and the potential ranges studied, the anodic charges are much greater than those corresponding to the H3BO3-borax solution, and metal corrosion combined with a solvent effect of the electrolyte is found. The greatest anodic charges are found for the H2SO4 solution (pH=1.0); the anodic current increases rapidly in the potential ranges studied due to pore initiation. The cathodic and anodic behaviour of aluminium depend strongly on the electrolyte employed, basically through the effect of the electrolyte on the oxide film and through the pH of the solution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01009136
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Potentiodynamic behaviour of aluminium in propanedioic acid solutions (1987)
    Springer
    Journal of applied electrochemistry 17 (1987), S. 807-812 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The electrochemical behaviour of aluminium in propanedioic acid solutions has been studied potentiodynamically, the sweep rates ranging from 1 to 100 mVs−1 and the concentrations of the diacid being 0.05, 0.10, 0.50 and 1.00 m. The experimental work has been carried out with and without stirring of the electrolyte. The potentiodynamic curves are simple but reflect a complex behaviour. The potential of zero current in the anodic sweep is made considerably more anodic when the concentration of propanedioic acid increases, when the sweep rate decreases and when stirring is introduced. For a certain sweep rate the cathodic charge increases with both stirring and concentration of propanedioic acid. However, the anodic charge, although increasing with concentration, does not depend on stirring within experimental error (potential ranges between −2.00 and 0.400 and −2.00 and 2.90 V vs SCE). The experimental curves are explained by the increase of the quantity of reducible species near the electrode with diacid concentration, by the fact that the cathodic process is pore diffusion-controlled (H2 evolution) and that near the potential of zero current the cathodic and anodic processes coexist (oxide formation and possible direct migration of the cation towards the solution).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01007818
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Potentiostatic study of the electrochemical nucleation of oxide films on cadmium in alkaline solutions (1987)
    Springer
    Journal of applied electrochemistry 17 (1987), S. 1093-1099 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A potentiostatic study of polycrystalline cadmium anodes (99.99%) in KOH solutions has been performed. The correspondingI-t curves obtained for potentials between −840 and −890mV (versus Hg/HgO, KOHsin) show a minimum and a maximum of current for all the concentrations of KOH empoloyed, except for 0.5 M. The mathematical treatment applied to the region appearing after the current minimum suggests that the cadmium oxide growth on the metal takes place according to a diffusion-controlled, three-dimensional hemispherical electrocrystallization with progressive nucleation. However, a change in the type of nucleation must be accepted, from progressive for short times to instantaneous for larger times. This change is more pronounced when the KOH concentration increases and explains the (I 2/J m 2 ) versus (t/t m) and the logI versus logt plots established for the different models of electrocrystallization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01024375
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Influence of the heat treatment in the electrochemical corrosion of Al-Zn-Mg alloys (1992)
    Springer
    Journal of applied electrochemistry 22 (1992), S. 541-552 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The localized corrosion of Al-(5.03%)Zn-(1.67%)Mg-(0.23%)Cu alloys and high purity Al has been studied using electrochemical techniques, optical microscopy, SEM and EDX. The samples were previously submitted to different heat treatments in which coherent and incoherent MgZn2 precipitates with different distribution and aggregation degree were produced. The influence of NaCl and Na2SO4, dissolved oxygen, immersion time and convection were studied. In NaCl solutions, pitting potentials for the alloys were more negative than for aluminium, indicating an increase in their susceptibility to localized corrosion. Moreover, annealed and cold-rolled alloys presented more negative pitting and repassivation potentials than those submitted to age hardening with direct or interrupted quenching. In annealed and cold-rolled samples, pit nucleation and propagation takes place in the zones where MgZn2 is accumulated. In the case of the age-hardened alloys, a double pitting behaviour is observed, the first one in the magnesium and zinc enriched regions and the second in the matrix. While the cold water quenched alloy is susceptible to stress corrosion craking, the alloy submitted to the interrupted quenching process is less susceptible to intergranular attack. The sulphate ion shifts the pitting potential of aluminium and the alloys by chloride towards more positive values because it impedes local accumulations of the latter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01024095
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    The influence of the electrochemical treatment on Cu-Al-Ag alloys in deaerated 0.5 M NaOH (1991)
    Springer
    Journal of applied electrochemistry 21 (1991), S. 446-451 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The effect of consecutive cyclic polarization in de-aerated 0.5 M NaOH solutions on the surface microstructure of mechanically polished Cu-Al-Ag alloys of different compositions and heat treatments has been studied using optical microscopy, SEM and EDS. The current peaks of the cyclic polarization curves do not depend on the alloy composition in the composition range studied. The repetitive potential scans between H2 and O2 evolution in alkaline media lead to preferential dissolution of aluminium, the roughness and phase composition of the surface of the alloys changing significantly. The quasistationaryI-E curves of the different Cu-Al-Ag alloys studied consist in the superposition of the quasistationaryI-E curves of high-purity Cu and Ag, the EDS microanalysis showing that aluminium is not present on the surface of the alloy in these conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01024583
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Effect of the addition of Cr and Nb on the microstructure and electrochemical corrosion of heat-treatable Al-Zn-Mg alloys (1995)
    Springer
    Journal of applied electrochemistry 25 (1995), S. 781-791 
    Details
    ISSN: 1572-8838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The effect of the addition of Cr and Nb on the microstructure and the electrochemical corrosion of the weldable, high-strength and stress corrosion cracking (SCC) resistant Al-5%Zn−1.67%Mg−0.23%Cu alloy (H) has been studied. Combined additions of the alloying elements, J (with Nb), L (with Cr) and O (with Cr and Nb) and different heat treatments, ST (cold-rolled), A (annealed), F (quenched), B (quenched and aged) and C (quenched in two steps and aged), to obtain different microstructures and hardness have been performed. To correlate the electrochemical corrosion with the microstructure of the specimens, corrosion potential (E cor) measurements in different chloride solutions were performed and optical microscopy, SEM, TEM and EDX were applied. In chloride solutions containing dissolved O2 or H2O2, the present alloys were polarized up to the pitting attack. It was shown that theE cor measurements were very sensitive to the alloy composition and heat treatment, increasing in the order H 〈 J 〈 L 〈 O 〈 Al (for a given heat treatment) and F 〈 A ≈ ST 〈 B 〈 C (for a given alloy). The MgZn2 precipitates of the annealed (A) and cold-rolled (ST) specimens were dissolved in chloride solutions containing oxidizing agents and pitting attack was shown to develop in the cavities where the precipitates were present. In the specimens B and C, the compositions of the precipitate free zones was found to be equal to that of the matrix solid solution and preferential intergranular attack was not evident, this being in agreement with their SCC resistance. The addition of Cr and Nb increased the pitting corrosion resistance. The effects of Cr and Nb were additive, that of Cr being predominant, either, in theE cor shift or in the increase in the pitting corrosion resistance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00648634
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    ViscosityB-coefficients for lithium perchlorate in ethylene glycol-water mixtures (1987)
    Springer
    Monatshefte für Chemie 118 (1987), S. 197-202 
    Details
    ISSN: 1434-4475
    Keywords: B-Coefficient ; Lithium perchlorate ; Ethylene glycol mixtures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wurden die Dichten und Viskositäten für Lösungen von Lithiumperchlorat in verschieden zusammengesetzten Ethylenglykol-Wasser-Mischungen bei 25 °C und 35 °C gemessen. Auf Grund der erhaltenen Daten wurden dieB-Koeffizienten in den entsprechendenJones-Dole-Gleichungen für die relative Viskosität bestimmt. DieB-Werte hängen von der Zusammensetzung des Lösungsmittels ab und erreichen im wasserreichen Konzentrationsgebiet ein Maximum. Dieses Verhalten wird in Hinblick auf die Ionensolvatation und die Struktur des Lösungsmittels analysiert.
    Notes: Abstract Viscosities and densities of lithium perchlorate solutions in different ethylene glycol-water compositions have been measured at 25.0 and 35.0 °C. From these data, the correspondingB-coefficients of theJones-Dole equation have been determined. TheB-value depends on the solvent composition and it reaches a maximum in the water-rich region. This behaviour is analysed in terms of ionic solvation and solvent structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00810052
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Observation sur la diffraction de la lumière par les tissus (1949)
    Springer
    Cellular and molecular life sciences 5 (1949), S. 65-66 
    Details
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Some particularities of the diffraction spectra produced by the lattice of a tissue have been discussed. An account is given of the apparition of supplementary diffraction maxima when the light-beam forms an angle ≠ 90° with the lattice-plane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02153725
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Presence of specific polypeptides in onion roots colonized by Glomus mosseae (1993)
    Springer
    Mycorrhiza 2 (1993), S. 175-177 
    Details
    ISSN: 1432-1890
    Keywords: Allium cepa ; Gene expression ; Glomus mosseae ; VA mycorrhizas ; Specific polypeptides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We studied changes in gene expression during the establishment of vesicular-arbuscular (VA) mycorrhizal symbiosis. Polypeptides were obtained by in vitro translation of total root RNA extracted from VA-colonized and noncolonized root-tissue of onion (Allium cepa L. cv. Babosa), and resolved by two-dimensional polyacrylamide gel electrophoresis. VA mycorrhization led to a specific appearance of eight new polypeptides, and the disappearance of seven polypeptides in VA-colonized root. Our findings indicate that gene expression is altered in response to morphological and physiological changes resulting from the establishment of VA mycorrhizas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00210587
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Interaction between Alternaria alternata or Fusarium equiseti and Glomus mosseae and its effects on plant growth (1997)
    Springer
    Biology and fertility of soils 24 (1997), S. 301-305 
    Details
    ISSN: 1432-0789
    Keywords: Key wordsAlternaria alternata ; Arbuscular mycorrhizas ; Fusarium equiseti ; Glomus mosseae ; Lactuca sativa ; Lettuce ; Maize ; Saprophytic fungi ; Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effect of inoculation with the saprophytic fungi Alternaria alternata or Fusarium equiseti on maize (Zea mays) and lettuce (Lactuca sativa) with or without arbuscular mycorrhizal (AM) colonization by Glomus mosseae was studied in a greenhouse trial. Plant dry weights of non-AM-inoculated maize and lettuce were unaffected by the presence of A. alternata and F. equiseti. In contrast, A. alternata and F. equiseti decreased plant dry weights and mycorrhization when inoculated to the rhizosphere before G. mosseae. The saprophytic fungi inoculated 2 weeks after G. mosseae did not affect the percentage of root length colonized by the AM endophyte, but did affect its metabolic activity assessed as succinate dehydrogenase activity. Although F. equiseti inoculated at the same time as G. mosseae did not affect mycorrhization of maize roots, its effect on AM colonization of lettuce roots was similar to that with A. alternata. In the rhizosphere of both plants, the population of saprophytic fungi decreased significantly, but was not affected by the presence of G. mosseae. Our results suggest that there may have been a direct effect of the saprophytic fungi on the mycorrhizal fungi in the extramatrical phase of the latter, and when the AM fungus was established in the root the AM fungus was less affected by the saprophytic fungi.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003740050247
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...