Library

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
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 3038-3045 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A new method has been applied to dynamically compact ceramic powders in the cylindrical configuration. In this method, a converging oblique detonation is used instead of the sliding detonation used in the standard method. The oblique detonation is generated by a configuration using two explosive layers. X-ray flash photographs have been made that show the detonation and shock fronts in both the standard and new configuration. In the present article, the shock wave and particle velocities in the B4C powder have been calculated using the shock and detonation angles obtained from the photographs in combination with the measured detonation velocity. In the two-layer configuration, the pressure applied to the powder was increased by a factor of 3.5 compared to the one-layer configuration, in agreement with calculations. The working principle of the two-layer configuration is discussed and compared with a computer simulation of the process. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applied composite materials 6 (1999), S. 139-165 
    ISSN: 1573-4897
    Keywords: shock-compaction ; ceramic-metal nozzle ; rocket nozzle ; venturi nozzle ; shock wave fabrication ; TiB2-Al composite ; cermet ; forming by shock compaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Shock compaction was used in the fabrication of high temperature ceramic-based materials. The materials' development was geared towards the fabrication of nozzles for rocket engines using solid propellants, for which the following metal-ceramic (cermet) materials were fabricated and tested: B4C-Ti (15 vol.-%), B4C-Al, and TiB2-Al, with an Al content typically between 15–20 vol.-%. Here, the B4C-Ti was only shock-compacted, while the other two cermets were shock compacted followed by melt infiltration with Al. The materials were subjected to gradually more severe testing conditions. Slabs of the materials were first tested for thermal shock resistance in an acetylene flame, followed by testing in the exhaust gas stream of a rocket propellant, and thereafter as a cylindrical insert in a nozzle of TZM alloy. The B4C-Ti composite showed erosion and cracking after the first test in the propellant flame, while the B4C-Al composite failed the insert tests. The TiB2-Al composite performed well under all conditions. A venturi nozzle of that material was formed during compaction. This real, shaped nozzle was shown to function well, even during repeated 3–6 s tests. This could be explained by the resistance of TiB2 to molten Al, the high thermal conductivity of the TiB2-Al cermet and the in situ formation of a protective layer, consisting mainly of Al2O3.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    International journal of colorectal disease 13 (1998), S. 256-259 
    ISSN: 1432-1262
    Keywords: Key words Crohn' disease ; Colonic resections ; Cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Previous reports suggest that up to 70% of patients undergoing surgery for Crohn's disease of the large bowel do not have gastrointestinal continuity restored and require a permanent ileostomy. In this study the experience with patients requiring surgical treatment of large bowel Crohn's disease is reviewed with particular reference to the management of the rectum. The records of 19 elective and 25 urgent colonic resections performed for large bowel Crohn's disease in 44 patients (16 males, 28 females; mean age 41 years, range 17–76) between 1983 and 1995 were reviewed. Staged proctectomy was performed in 5 of 12 patients who had colectomy for acute colitis and in one patient who had had an elective colectomy. Permanent ileostomy was required in 72% of patients with acute Crohn's colitis and 84% of patients who had elective surgery for large bowel Crohn's. Over 70% of patients having surgical treatment of Crohn's disease of the large bowel required permanent ileostomy. No cases of cancer developed in patients with retained rectal stumps.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...