22,711 research outputs found
Coercivity of domain wall motion in thin films of amorphous rare earth-transition metal alloys
Computer simulations of a two dimensional lattice of magnetic dipoles are performed on the Connection Machine. The lattice is a discrete model for thin films of amorphous rare-earth transition metal alloys, which have application as the storage media in erasable optical data storage systems. In these simulations, the dipoles follow the dynamic Landau-Lifshitz-Gilbert equation under the influence of an effective field arising from local anisotropy, near-neighbor exchange, classical dipole-dipole interactions, and an externally applied field. Various sources of coercivity, such as defects and/or inhomogeneities in the lattice, are introduced and the subsequent motion of domain walls in response to external fields is investigated
Measurements of aerosol properties needed to infer backscatter characteristics in support of the NASA Doppler Lidar program
During the first year two areas of work were emphasized, analysis of aerosol data to provide improved estimates of backscatter over the Pacific ocean and development of a global model for backscatter at different wavelengths and preparation and planning for the aircraft flights of the GLOVE program. Significant progress was made in each of these areas. The analytical work is a continuation of the GAMETAG analysis, and was directed toward the development of a backscatter model for the Pacific Oceanic free troposphere. This has included a further evaluation of relationships between the optical effects at different wavelengths, a comparison of modeled optical effects at differing temporal resolutions, and an investigation of the effects of sampling on the modeled results. An initial investigation of the predictability of 9 to 10 micrometers Beta values from other data sets as well as some preliminary comparisons of the modeling results with experimental data. The comparison of the optical effects was extended to make the comparisons for different sets of time bases between 1 and 20 minutes
Genesis of breath sounds-Preliminary verification of theory
Experimental results are presented which tend to validate a previously developed theory of sound production in the human lung over a particular Reynolds number range. In addition, a new, presently nonunderstood, phenomenon was observed at higher Reynolds number. These results, which show how sound generation in the lung depends upon the physiologically important variables of volume flow rate and bronchial diameter, have potentially important application in noninvasive lung examination and the diagnosis of lung disease
Search for the electric dipole moment of the electron with thorium monoxide
The electric dipole moment of the electron (eEDM) is a signature of
CP-violating physics beyond the Standard Model. We describe an ongoing
experiment to measure or set improved limits to the eEDM, using a cold beam of
thorium monoxide (ThO) molecules. The metastable state in ThO
has important advantages for such an experiment. We argue that the statistical
uncertainty of an eEDM measurement could be improved by as much as 3 orders of
magnitude compared to the current experimental limit, in a first-generation
apparatus using a cold ThO beam. We describe our measurements of the state
lifetime and the production of ThO molecules in a beam, which provide crucial
data for the eEDM sensitivity estimate. ThO also has ideal properties for the
rejection of a number of known systematic errors; these properties and their
implications are described.Comment: v2: Equation (11) correcte
Building work engagement: A systematic review and meta-analysis investigating the effectiveness of work engagement interventions
Low work engagement may contribute towards decreased well-being and work performance.
Evaluating, boosting, and sustaining work engagement is therefore of interest to many
organizations. However, the evidence on which to base interventions has not yet been
synthesised. A systematic review with meta-analysis was conducted to assess the evidence for the
effectiveness of work engagement interventions. A systematic literature search identified
controlled workplace interventions employing a validated measure of work engagement. Most
used the Utrecht Work Engagement Scale (UWES). Studies containing the relevant quantitative
data underwent random-effects meta-analyses. Results were assessed for homogeneity,
systematic sampling error, publication bias, and quality. Twenty studies met the inclusion criteria
and were categorised into four types of interventions: 1) personal resource building; 2) job
resource building; 3) leadership training; and 4) health promotion. The overall effect on work
engagement was small, but positive, k=14, Hedges g=0.29, 95%-CI=0.12-0.46. Moderator
analyses revealed a significant result for intervention style, with a medium to large effect for
group interventions. Heterogeneity between the studies was high, and the success of
implementation varied. More studies are needed, and researchers are encouraged to collaborate
closely with organizations to design interventions appropriate to individual contexts and settings,
and include evaluations of intervention implementation
- …