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
    Characterization of the porous structure of soils: adsorption of nitrogen (77 K) and carbon dioxide (273 K), and mercury porosimetry (1999)
    Oxford, UK : Blackwell Science Ltd
    European journal of soil science 50 (1999), S. 0 
    Details
    ISSN: 1365-2389
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Accessibility of adsorbates to internal active sites of soils depends mainly on the porous structure of the material. We aimed to determine the distribution of pore sizes in soils with varied physico-chemical properties, by combining adsorption of gases and mercury porosimetry. Microporosity was studied by physical adsorption of N2 at 77 K and CO2 at 273 K; mercury intrusion porosimetry allowed us to evaluate the macroporosity; and mesoporosity was determined by capillary condensation of N2 and mercury porosimetry. The soils investigated were essentially macroporous, with volumes between 0.33 and 0.73 cm3 g–1; the maxima in the differential pore-size distribution were in the range 1500–4000 nm. Volumes of meso- or micropores were always less than 10% of macropore volumes. Calculations based on the theory of Dubinin and the αs-method (for N2 at 77 K) provided, generally, coincident results. In a soil containing much organic matter, N2 adsorption was only one-ninth that of CO2 adsorption, showing that N2 adsorption into the narrow micropores of organic matter was kinetically restricted. When accessibility to micropores was not restricted, the total volume of micropores could be deduced from N2 adsorption, whereas CO2 measured exclusively the narrowest microporosity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2389.1999.00261.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Passivation, structural modification, and etching of amorphous silicon in hydrogen plasmas (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 7612-7618 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Atomic hydrogen from plasma discharges dissolves in silicon previously amorphized by ion implantation (aSi) in the form of Si–H bonds, giving rise to infrared (IR) absorption at ∼1990 cm−1 and causing partial activation of implanted dopants. Passivation of aSi does not affect the rate at which the material subsequently undergoes solid phase epitaxy. Exposure giving rise to [H]〉6 at. % causes the appearance of an additional IR absorption band at ∼2080 cm−1 and coloration of the layer. Despite annealing, the Si–H defects, normal solid phase epitaxy does not occur during subsequent heat treatment. The structural modification by H-plasma exposure coincides with etching of the layer. The observations can be understood in terms of void formation in aSi resulting from the clustering of Si–H. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.365337
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Rapid solid phase crystallization of nanocrystalline silicon deposited by electron cyclotron plasma chemical vapor deposition (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 69 (1996), S. 1873-1875 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Nanocrystalline silicon films were deposited in an electron cyclotron resonance plasma of Ar+H2+SiH4 on (100) and (111) oriented Si substrates without external heating. Before deposition, the substrates were cleaned in situ in an Ar+H2 plasma. This cleaning process caused surface roughness particularly on (100) substrates. Apparently, the excessive roughness of the interface with (100) Si surface prevented complete crystallization of the subsequently deposited films. In contrast, rapid solid phase crystallization of the films deposited on (111) surfaces occurred at around 1000 °C. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.117462
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Photoconductor gain mechanisms in GaN ultraviolet detectors (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 71 (1997), S. 870-872 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: GaN photoconductive detectors have been fabricated on sapphire substrates by metal organic vapor phase epitaxy and gas-source molecular beam epitaxy on Si (111) substrates. The photodetectors showed high photoconductor gains, a very nonlinear response with illuminating power, and an intrinsic nonexponential photoconductance recovery process. A novel photoconductor gain mechanism is proposed to explain such results, based on a modulation of the conductive volume of the layer. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.119673
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Polarization fields determination in AlGaN/GaN heterostructure field-effect transistors from charge control analysis (1999)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 2407-2409 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: AlxGa1−xN/GaN heterostructure field-effect transistors with different Al concentrations (0.15〈x〈0.25) and barrier widths (150 Å〈WB〈350 Å) have been fabricated and characterized. Experimental results were analyzed by using a self-consistent solution of the Schrödinger and Poisson equations with the proper boundary conditions. The total (piezoelectric and spontaneous) polarization has been included as a fitting parameter in the self-consistent calculations. From the analysis of the transistor charge-control experimental data, a linear increase of the polarization field with the Al concentration has been found. Our results indicate that the slope of such dependence, and the magnitude of the total polarization field are lower than the predicted ones using the usually accepted values of the piezoelectric and spontaneous polarization coefficients. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.125029
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Detection of Ethylene-Ozone and Cyclohexene-Ozone Charge-Transfer Complexes in Cryogenic Matrixes (1995)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 117 (1995), S. 562-563 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00106a077
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Design and simulation of an industrial automated overhead warehouse (1998)
    Bradford : Emerald
    Integrated manufacturing systems 9 (1998), S. 308-313 
    Details
    ISSN: 0957-6061
    Source: Emerald Fulltext Archive Database 1994-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Economics
    Notes: This paper is a description of an automated overhead warehouse system, developed to store car seat covers and then to feed them to the Renault car assembly plant at Palencia (Spain). It is based on trolleys moved through monorails and stored in accumulation bars (or monorails) by gravity, having to fulfil space and shape constraints, low retrieval time requirements, etc. This paper presents the decision process and the solutions adopted in this project to overcome the constraints and to fulfil the specifications. Also, a simulation tool integrated in an object- oriented designing framework is presented. It has been developed to support the decision-making process, especially at the very beginning of the project.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1108/09576069810230419
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    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
  • 9
    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
  • 10
    Electronic Resource
    Electronic Resource
    Temperature evolution during scanning electron beam processing of silicon (1996)
    Springer
    Applied physics 62 (1996), S. 451-457 
    Details
    ISSN: 1432-0630
    Keywords: 44.30 ; 79.20 ; 81.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Temperature profile evolutions produced by a scanning electron beam in crystalline silicon have been numerically calculated using a two-dimensional finite-element scheme. The temperature dependence of the different silicon properties as well as the electron penetration effects have been taken into account. Numerical calculations carried out at different conditions have been compared with experimental melting-threshold measurements using an electron beam with a Gaussian power density distribution. The good agreement between numerical calculations and experimental results proves the validity of the two-dimensional approach.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01567116
    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...