The crack of doom.

Mode of access: Internet.

Cocaine and a changing brain : meeting summary : Ernest Morial Convention Center, New Orleans, LA, October 25, 1997 : sponsored by Division of Basic Research, National Institute on Drug Abuse, National Institutes of Health /

"January 1999"--P. [4] of cover.

Price and purity of cocaine : the relationship to emergency room visits and death, and to drug use among arrestees.

"October 1992"--Cover.

The life styles of nine American cocaine users : trips to the Land of Cockaigne /

Mode of access: Internet.

Straight thinking on narcotics: alcohol, tobacco, opium, morphine, cocaine, and marihuana.

Bibliography: 165-171.

Crack propagation in plain concrete /

Mode of access: Internet.

Crack & crunch; nuts in fact and fancy,

Mode of access: Internet.

Crack o' dawn,

Mode of access: Internet.

Proceedings of the Second International Atomic Energy Agency Specialists' Meeting on Subcritical Crack Growth, held at Sendai, Japan, May 15-17, 1985 /

"MEA-2090."

Crack detection in welded mechanical structures using coupled vibrations

Detection of a fatigue crack in a welded frame structure is studied in this paper using coupled response measurements. Similarity to real engineering structures is maintained in the fabrication of the test frame with hollow section chords and branch members. The fatigue crack was created by a special reciprocating mechanism that generates cyclic stress on a beam member of the structure. The methodology of coupled response measurements is first demonstrated on a single hollow section beam by analytical simulation and experimental validation. The issues of using this approach for fatigue crack detection in real structures are then examined. Finally, the experimental results of the frame under different scenarioes are presented. The existence of the crack is clearly observable from the FRF plots. It is suggested that this approach offers the potential to detect cracks in welded frame structures and is a useful tool for routine maintenance work and health assessment.

Ethical issues in using a cocaine vaccine to treat and prevent cocaine abuse and dependence

A cocaine vaccine'' is a promising immunotherapeutic approach to treating cocaine dependence which induces the immune system to form antibodies that prevent cocaine from crossing the blood brain barrier to act on receptor sites in the brain. Studies in rats show that cocaine antibodies block cocaine from reaching the brain and prevent the reinstatement of cocaine self administration. A successful phase 1 trial of a human cocaine vaccine has been reported. The most promising application of a cocaine vaccine is to prevent relapse to dependence in abstinent users who voluntarily enter treatment. Any use of a vaccine to treat cocaine addicts under legal coercion raises major ethical issues. If this is done at all, it should be carefully trialled first, and only after considerable clinical experience has been obtained in using the vaccine to treat voluntary patients. There will need to be an informed community debate about what role, if any, a cocaine vaccine may have as a way of preventing cocaine addiction in children and adolescents.