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
    Improvement of corrosion resistance of carbon steel using chemical vapor deposition from the mixture of Mo(CO)6 and Cr(CO)6 with an ArF-excimer laser (1994)
    Springer
    Applied physics 58 (1994), S. 99-105 
    Details
    ISSN: 1432-0630
    Keywords: 81.15 ; 81.60 ; 68.55
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The corrosion resistance of carbon steel has been improved by the deposition from the mixture of Mo(CO)6 and Cr(CO)6 as well as from each carbonyl alone with an ArF-excimer laser (193 nm). The corrosion resistance attained by coating with the films from the mixture is higher than from Mo(CO)6 alone, while lower than from Cr(CO)6 alone. While the corrosion resistance increases with beam intensity monotonically over the range 4–25 MW cm−2 for the deposition from Cr(CO)6 alone, it tends to decrease slightly above 15 MW cm−2 for the deposition from Mo(CO)6 alone and from the mixture. SEM (Scanning Electron Microscope) photographs show that the films from each carbonyl and their mixture consist of small grains that are more densely packed at higher beam intensities. The comparison of the film thickness evaluated from sputtering time to remove the films with that from direct observation with SEM suggests that the density of the film increases with beam intensity. In the films deposited from the mixture, molybdenum is preferentially incorporated from the gas phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00331525
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Disktron accelerator (1993)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 64 (1993), S. 2466-2474 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A new type of low-energy ion accelerator has been developed. It includes an eight-storied Disktron generator, newly developed accelerating tubes which hold up to 4 MV/m, both single and tandem acceleration capability, and a compound negative ion source. The Disktron generates 3.2 MV with a dummy load and 2.2 MV with ion beams, and has a voltage stability better than 10−3 at around 1 MV with a corona feedback stabilizer or a generating voltmeter feedback stabilizer only. The highly stabilized voltage of the Disktron has particularly been allowed to form an ion microbeam of about 1-μm diameter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1143905
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Construction of a physical map of the chromosome of Shigella flexneri 2a and the direct assignment of nine virulence-associated loci identified by Tn5 insertions (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Molecular microbiology 5 (1991), S. 0 
    Details
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: To establish the molecular basis of the chromosomal virulence genes of Shigella flexneri 2a (YSH6000), a Notl restriction map of the chromosome was constructed by exploiting Notl-linking clones, partial Notl digestion and DNA probes from various genes of Escherichia coli K-12. The map revealed at least three local differences in the placements of genes between YSH6000 and E. coli K-12. Using the additional Notl sites introduced by Tn5 insertion, nine virulence loci Identified previously by random Tn5 insertions were physically mapped on the chromosome. To demonstrate the versatility of the Notl map in direct assignment of the virulence loci tagged by Tn5 to a known genetic region in E. coli K-12, the major class of avirulent mutants defective in the core structure of lipopolysaccharide (LPS) was examined for the sites of Tn5 insertions. The two Notl segments created by the Tn5 insertion in the Notl fragment were analysed by Southern blotting with two DNA probes for the 5′ and 3’flanking regions of the rfa region, and shown to hybridize separately with each of them, confirming the sites of Tn5 in the rfa locus. This approach will facilitate direct comparison of genetically mapped Tn5 insertion mutations of S. flexneri with genes physically determined in E. coli K-12.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2958.1991.tb02147.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Virulence-associated chromosomal loci of Shigella flexneri identified by random Tn5 insertion mutagenesis (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Molecular microbiology 5 (1991), S. 0 
    Details
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Shigellae are the causative agents of bacillary dysentery and are capable of invading epithelial cells, multiplying therein and spreading into adjacent cells. To identify genes on the chromosome associated with the virulence phenotype, 9114 independent Tn5 insertion mutants were isolated in a virulent strain of Shigella flexneri. By using an in vitro assay for intercellular spread or an animal infection model, the Serény test, 50 chromosomal Tn5 mutants with reduced virulence were identified. The 50 mutants were characterized with respect to their virulence phenotypes, including three different mutations that affect invasion of epithelial cells, bacterial metabolism and structure of lipopolysaccharide. Mutants with reduced invasive ability were further characterized and it was found that two of them had decreased levels of IpaB, C and D antigens as well as the mRNA for the ipaBCD operon encoded by the large virulence plasmid, suggesting that positive regulatory elements for the IpaBCD operon are encoded by the chromosome. Assignment of the 50 Tn5 insertions of the mutants to the 19 Notl restriction fragments of the chromosomal DNA has permitted the identification of at least nine virulence-associated chromosomal loci.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2958.1991.tb01839.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Temperature-regulated expression of invasion genes in Shigella flexneri is controlled through the transcriptional activation of the virB gene on the large plasmid (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Molecular microbiology 5 (1991), S. 0 
    Details
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The invasion phenotype of shigellae is subject to thermoregulation that is known to be expressed through activation of some invasion (inv) genes such as ipaB, ipaC, and ipaD encoded by the large virulence plasmid of Shigeila flexneri. The expression of ipa genes is regulated positively by virF through the activation of virB on the plasmid. To identify the mediator for the thermoregulation of the large plasmid, we have studied the effect of temperature on the transcription of virF and virB genes and ipa and the other two inv operons. The results showed that transcription of VirB was affected by temperature more strictly than that of virF. Analysis of the mRNA level of virB at different levels of virF transcription indicated that virB transcription depended upon both temperature and virF. On the other hand, transcriptions of ipa and the other two inv operons depended on the activation of virB transcription but not on temperature. By inducing wr8 transcription from a tac promoter fused with the virB region, invasion ability was restored to a WrF-deletion mutant at 30°C as well as at 37°C. By using conditions in which the temperature-dependent expression of the invasion phenotype was circumvented by the induction of virB transcription, intercellular spreading ability in a virF+, virB::Tn5 strain was shown to be expressed even at 30°C. These results suggest that the virB transcription stage is the main target for the thermoregulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2958.1991.tb00762.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Identification and characterization of virK, a virulence-associated large plasmid gene essential for intercellular spreading of Shigella flexneri (1992)
    Oxford, UK : Blackwell Publishing Ltd
    Molecular microbiology 6 (1992), S. 0 
    Details
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Seven virulence loci have been identified by Tn5 insertion mutagenesis on the large 230 kb plasmid (pMYSH6000) of Shigella flexneri 2a. In this study, we used Tn10 insertion mutagenesis and identified a novel virulence locus on pMYSH6000 responsible for bacterial spread. Characterization of the invading bacteria of the Tn10 insertion mutants in the epithelial cells revealed that the bacteria were capable of at least some intracellular spreading but not intercellular spreading. Immunoblot analysis of lysates of the Tn10 insertion mutants with a VirG-specific antipeptide antibody revealed diminished levels of the 116 kDa VirG protein. The virG mRNA in the mutants, however, was expressed at the same level as that in the wild type. The DNA region required for the virulence phenotype was localized to a 1.6 kb DNA sequence in the Sal I-K fragment on the plasmid, and thus the locus was designated virK. Expression of virK in Escherichia coli using a T7 RNA polymerase-dependent promoter system yielded a 36 kDa protein. The nucleotide sequence of 1642 bp encoding VirK function was determined, and an open reading frame encoding 316 amino acid residues was shown to encode the VirK protein. The virK region was highly conserved among the large virulence plasmids of shigellae and enteroinvasive Escherichia coli. These results suggest that VirK function is an essential virulence determinant for shigellae Involved in the expression of virG gene product at post-transcriptional level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2958.1992.tb01413.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Optimal operation model of a single reservoir with drought duration explicitly concerned (1992)
    Springer
    Stochastic environmental research and risk assessment 6 (1992), S. 123-134 
    Details
    ISSN: 1436-3259
    Keywords: Reliability analysis ; Drought duration ; Reservoir operation ; Markov decision process
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract In this paper, a new model for a single reservoir operation optimization is proposed. The proposed model can design the optimal operation policy of a reservoir with explicit consideration of drought duration. The authors model this problem by formulating a single-stage loss function as a function of both the reservoir release and drought duration. Thereby the expected loss per period which is calculated based on the above extended single-stage loss function is minimized in infinite time horizon on the basis of Markov decision process (MDP) theory. The reliability indices are estimated as expected loss per period for specified extended loss functions. Finally, the features of the proposed model are illustrated through numerical analysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01591334
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Improvement of corrosion resistance of carbon steel using chemical vapor deposition from Cr(CO)6 with an ArF excimer laser (1992)
    Springer
    Applied physics 55 (1992), S. 207-212 
    Details
    ISSN: 1432-0630
    Keywords: 81.15 ; 81.60 ; 68.55
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Corrosion resistance of carbon steel coated with thin film deposited from Cr(CO)6 using an ArF excimer laser (193 nm) has been evaluated by an electrochemical method as a function of laser beam intensity. The carbon steel coated with the film formed at higher beam intensity shows higher corrosion resistance. Microstructure, composition, and thickness of the films have also been investigated. SEM micrographs show that the films consist of small grains which decrease in size with increasing beam intensity. Auger electron spectroscopy (AES) combined with Ar+ beam sputtering reveals that the films deposited at higher beam intensity give higher chromium content, and that the thickness at a fixed total irradiation energy increases up to the intensity of 10 MW cm−2, falling above this intensity. In addition, the change of film thickness by addition of buffer gases (Ar, CO, and H2O) has been investigated. The thickness is 10 times smaller under the addition of H2O, and twice smaller under the addition of Ar or CO than without the addition of gases. A deposition mechanism based on photolysis of Cr(CO)6 in the gas phase is proposed related to the experimental data after the discussion of several possible mechanisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00334225
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Modeling of gas-phase processes in laser-induced chemical vapor deposition from Cr(CO)6 with an excimer laser (1993)
    Springer
    Applied physics 56 (1993), S. 138-146 
    Details
    ISSN: 1432-0630
    Keywords: 81.15 ; 68.55 ; 82.20
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Laser-induced chemical vapor deposition from Cr(CO)6 with an excimer laser has been modeled and simulated to investigate the kinetics and mechanisms of the deposition. The model concerns gas-phase processes including photolysis of Cr(CO)6, transportation of photofragments to the substrate surface, and elimination of photofragments through chemical reactions during transportation. The photofragments are eliminated through the reforming to Cr(CO)6 that is divided into the two stages: stabilization of the photofragments in excited states by collisions with buffer gases (CO, Ar) and recombination of the photofragments in the ground state with CO. The simulation shows that the deposition rate without additional buffer gases is of the same order as the experimental rate and that deposition rates in the presence of additional CO and Ar agree qualitatively with experimental results. This suggests that the supply of Cr species to the substrate surface is mainly controlled by the gas-phase processes where the chemical reactions eliminating photofragments play an important role. Applications of the model for the deposition under other conditions are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00517681
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    facet.materialart.
    Unknown
    Several short interspersed repetitive elements (SINEs) in distant species may have originated from a common ancestral retrovirus: characterization of a squid SINE and a possible mechanism for generation of tRNA-derived retroposons. (1993)
    National Academy of Sciences
    Details
    Publication Date: 1993-07-01
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...