Suchergebnisse

A spiritual journey -- Are there realities science cannot explain? -- What is faith? -- Do scientists have faith? -- Does reason support Christian belief? -- What is scientism? -- Is there really spiritual knowledge? -- Creation and cosmology -- Do miracles happen? -- The Bible and science -- Of all the world's religions, why Christianity? -- Why does God seem hidden? -- Is there good and evil? -- Personal consequences: so what?

AbstractWe investigated the extent to which commitment versus control‐based safety practices and occupational safety reputation influence perceived safety climate. Both these variables were manipulated experimentally using a vignette approach, creating a 2 × 2 design (safety practices vs. safety reputation). We hypothesized that any effects of safety practices would be direct, as well as mediated by trust in management and affective commitment, while the effects of safety reputation would only be direct. We also expected that the interaction of safety reputation and safety practices would yield stronger effects than either of the variables operating individual‐ly. There was substantial support for the direct and indirect effects of safety practices. In contrast, safety reputation exerted neither direct nor indirect effects. There were no significant interactions. We suggest directions for further research on the optimal management of occupational safety.RésuméNous avons étudié l'ampleur avec laquelle les pratiques de sécurité, centrées sur l'engagement comparativement à celles centrées sur le contrǒle, et la réputation de sécurité au travail influencent la perception du climat de sécurité. Ces deux variables ont été manipulées expérimentalement par l'utilisation d'une vignette, en créant un modèle 2 times 2 (pratiques de sécurité par rapport à réputation de sécurité). Nous avons posé l'hypothèse que les pratiques de sécurité entraǐnaient, en plus des effets directs, des effets indirects grǎce à la confiance envers les gestionnaires et l'engagement affectif alors que la réputation de sécurité n'avait que des effets directs. Nous avons aussi envisagé que l'interaction de la réputation de sécurité et des pratiques de sécurité produisait un effet plus marqué que chacune des deux variables opérant séparément. Nos résultats ont largement corroboré l'hypothèse relative aux effets directs et indirects des pratiques de sécurité; par contre, il s'est avéré que la réputation de sécurité n'avait ni effet direct ni indirect. Par ailleurs, il n'y avait aucune interaction significative. Nous proposons aussi quelques lignes directrices pour de nouvelles recherches sur la gestion optimale de la sécurité au travail.

The object of this review is to summarize the achievements of research on the Alcator C-Mod tokamak [Hutchinson et al., Phys. Plasmas 1, 1511 (1994) and Marmar, Fusion Sci. Technol. 51, 261 (2007)] and to place that research in the context of the quest for practical fusion energy. C-Mod is a compact, high-field tokamak, whose unique design and operating parameters have produced a wealth of new and important results since it began operation in 1993, contributing data that extends tests of critical physical models into new parameter ranges and into new regimes. Using only high-power radio frequency (RF) waves for heating and current drive with innovative launching structures, C-Mod operates routinely at reactor level power densities and achieves plasma pressures higher than any other toroidal confinement device. C-Mod spearheaded the development of the vertical-target divertor and has always operated with high-Z metal plasma facing components—approaches subsequently adopted for ITER. C-Mod has made ground-breaking discoveries in divertor physics and plasma-material interactions at reactor-like power and particle fluxes and elucidated the critical role of cross-field transport in divertor operation, edge flows and the tokamak density limit. C-Mod developed the I-mode and the Enhanced Dα H-mode regimes, which have high performance without large edge localized modes and with pedestal transport self-regulated by short-wavelength electromagnetic waves. C-Mod has carried out pioneering studies of intrinsic rotation and demonstrated that self-generated flow shear can be strong enough in some cases to significantly modify transport. C-Mod made the first quantitative link between the pedestal temperature and the H-mode's performance, showing that the observed self-similar temperature profiles were consistent with critical-gradient-length theories and followed up with quantitative tests of nonlinear gyrokinetic models. RF research highlights include direct experimental observation of ion cyclotron range of frequency (ICRF) mode-conversion, ICRF flow drive, demonstration of lower-hybrid current drive at ITER-like densities and fields and, using a set of novel diagnostics, extensive validation of advanced RF codes. Disruption studies on C-Mod provided the first observation of non-axisymmetric halo currents and non-axisymmetric radiation in mitigated disruptions. A summary of important achievements and discoveries are included. ; United States. Dept. of Energy (Cooperative Agreement DE-FC02-99ER54512) ; United States. Dept. of Energy (Cooperative Agreement DE-FG03-94ER-54241) ; United States. Dept. of Energy (Cooperative Agreement DE-AC02-78ET- 51013) ; United States. Dept. of Energy (Cooperative Agreement DE-AC02-09CH11466) ; United States. Dept. of Energy (Cooperative Agreement DE-FG02-95ER54309) ; United States. Dept. of Energy (Cooperative Agreement DE-AC02-05CH11231) ; United States. Dept. of Energy (Cooperative Agreement DE-AC52-07NA27344) ; United States. Dept. of Energy (Cooperative Agreement DE-FG02- 97ER54392) ; United States. Dept. of Energy (Cooperative Agreement DE-SC00-02060)