Condom use: A self-efficacy model.

A survey of heterosexually active college students gathered information about condom use, self-efficacy (SE), outcome expectancies, sexual attitudes, peer group influences, AIDS knowledge, and a perceived vulnerability to AIDS. On the basis of A. Bandura's (1986) social-cognitive theory, a structural model with SE as the central mediator was formulated and evaluated with LISREL. This model explained 46% of the variance in condom use from judgments of SE and effects attributable to peers and 53% of the variance in SE from outcome expectancies and peer group influences. Sexual attitudes, AIDS knowledge, and perceived vulnerability did not predict condom use. Most students were well-informed about HIV transmission but reported not feeling at risk, even though many engaged in risky sexual behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermisch induzierter Abbau von Disaccharid-Amadori-Verbindungen in quasi wasserfreiem Reaktionsmilieu

Ohne Zusammenfassung     

Phenomena-based thermal-hydraulic modeling requirements for systems analysis of a Modular High Temperature Gas-Cooled Reactor

The Modular High Temperature Gas-Cooled Reactor (MHTGR) is a candidate design for new production and commercial power nuclear reactors. The MHTGR has inherent safety features including: (1) passive shutdown and decay heat removal, (2) reduced requirements for operator intervention, thereby reducing sensitivity to operator error, and (3) long time intervals for corrective action. In support of the Department of Energy's (DOE) initial development of the design, the authors have completed an evaluation of the thermal-hydraulic phenomena that will dominate the plant response during representative normal, off-normal and accident conditions. Phenomena having significance to the plant behavior have been identified, and ranked with respect to their relative importance in satisfying operational, investment and/or safety criteria. The resulting information provides the basis for evaluating the applicability of existing computer codes, and defines the requirements for the development of new codes, for thermal-hydraulic systems analysis. The phenomena-based requirements also support the quality assurance related verification and validation of these codes. This paper briefly describes the methodology employed, and gives illustrative examples of the resulting requirements. References are cited for reports that document the full body of requirements and provide additional information for the methodology.     

Verteilung der N?hrstoffe im Tabak

Ohne Zusammenfassung     

Machining of reproducible flaws corresponding to fatigue cracks for fracture mechanics tests of components and welded joints

In connection with the analysis and the development of failure concepts in fracture mechanics for quasistatic loaded components and elastic-plastic behaviour of the material, tests are also carried out with welded and/or complex shaped specimens or structures. Thereby the difficulty arises of generating reproducible flaws in the form of fatigue precracks in definite positions in the components, respectively in the welded joint. It is reported exemplarily about experiments on different CT25 and CCT specimens and on a pressure vessel which contained a fatigue pre-crack, a 0.2 mm saw cut or notches with notch root radius ≤ ≥ 0.1 mm as flaws. The comparison of the results with regard to J-integral at initiation of stable crack, J_i, and J_R curves shows that under certain conditions the 0.2 mm saw cut (notch root radius ≤ ≤ 0.02 mm) is a useful alternative, if reproducible generation of a fatigue pre-crack will not be successful or too expensive. The tests were carried out on StE 460 and on a welded joint of this steel at 25 ± 2°C.     

IV. Referate

Ohne Zusammenfassung