1,738 research outputs found
Atmospheric composition affects heat- and mass-transfer processes
For environmental control system functions sensitive to atmospheric composition, components are test-operated in helium-oxygen and nitrogen-oxygen mixtures, pure oxygen, and air. Transient heat- and mass-transfer tests are conducted for carbon dioxide adsorption on molecular sieve and for water vapor adsorption on silica gel
Experimental demonstration of four-party quantum secret sharing
Secret sharing is a multiparty cryptographic task in which some secret
information is splitted into several pieces which are distributed among the
participants such that only an authorized set of participants can reconstruct
the original secret. Similar to quantum key distribution, in quantum secret
sharing, the secrecy of the shared information relies not on computational
assumptions, but on laws of quantum physics. Here, we present an experimental
demonstration of four-party quantum secret sharing via the resource of
four-photon entanglement
The Impact of Foreign Postings on Accompanying Military Spouses: An Ethnographic Study.
As part of an ethnographic study, the impact of foreign postings on spouses who accompany military personnel was explored. Individual interviews and focus groups with 34 British military spouses based in one location in southern Europe were conducted. Key findings suggested that reaction to a foreign posting was a reflection of personal attitudes, prior experiences, support, ability to adjust to change and strength of relationship with the serving spouse and community. For many the experience was positive due to the increased opportunity for family time, for others this helped to compensate for the difficulties experienced. Some military spouses experienced significant distress on the posting, particularly if the family was not well-supported. The potential implications of military spouses not adapting to foreign postings have significant implications for healthcare practice. Provision of more appropriate support resources before and during the posting would facilitate the transition for the military spouse and their family
Kinetics of Surface Enrichment: A Molecular Dynamics Study
We use molecular dynamics (MD) to study the kinetics of surface enrichment
(SE) in a stable homogeneous mixture (AB), placed in contact with a surface
which preferentially attracts A. The SE profiles show a characteristic
double-exponential behavior with two length scales: \xi_-, which rapidly
saturates to its equilibrium value, and \xi_+, which diverges as a power-law
with time (\xi_+ \sim t^\theta). We find that hydrodynamic effects result in a
crossover of the growth exponent from \theta \simeq 0.5 to \theta \simeq 1.0.
There is also a corresponding crossover in the growth dynamics of the SE-layer
thickness.Comment: 20 pages, 6 figures, Published in J. Chem. Phys. (Research
Highlights
Controlling Fast Chaos in Delay Dynamical Systems
We introduce a novel approach for controlling fast chaos in time-delay
dynamical systems and use it to control a chaotic photonic device with a
characteristic time scale of ~12 ns. Our approach is a prescription for how to
implement existing chaos control algorithms in a way that exploits the system's
inherent time-delay and allows control even in the presence of substantial
control-loop latency (the finite time it takes signals to propagate through the
components in the controller). This research paves the way for applications
exploiting fast control of chaos, such as chaos-based communication schemes and
stabilizing the behavior of ultrafast lasers.Comment: 4 pages, 4 figures, to be published in Physical Review Letter
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Perceptions of volunteering and community service : voices of post-secondary remedial completer
Although community colleges have emphasized service-learning programs for traditional students, by in large, non-traditional students from post-secondary remedial programs have not been involved. This lack of reaching post-secondary remedial programs may be of particular interest to college personnel who may not be aware of the need to include service activities for non-traditional students in ways that will help them become caring individuals and strive toward a positive future. This study was guided by the following research questions: 1. What are the perceptions of Skill Center completers who were involved in volunteering and community service? 2. What are the opportunities for connecting their service involvement to the community college? The study examined the perceptions of 15 former post-secondary remedial students involved in community service and volunteering. All of the participants in the study were persons of color, 12 of the l5 were identified as African-American, one as Latino, and one as Asian. The data were collected through in-depth interviews conducted by the researcher from a participant-observer position and focused on service interactions and the types of understandings each participant developed in relation to the people they met. Voices of post-secondary remedial students who successfully complete volunteering or community service activities on their own and without any college sponsorship are rarely heard. Participants in this study described a variety of service experiences that provided insight into the social connection among a community of people. The most often cited themes were the participants' personal service reflections, their relationship with others, community building, and their motivation for service. Critical benefits to the participants were how service involvement helped clarify their life and allowed them to learn more about themselves. Participants told of the advantages of working together and being committed to the community, which gave them a sense of connection. Participants also revealed that volunteering actually opened doors for employment opportunities. These experiences were beneficial both from the viewpoint of the acquisition of skills and a feeling of personal ownership and pride. Another benefit for participants engaged in service was to transform their feelings into an ethic of caring, social capital, and personal transformation
Trends in absolute socioeconomic inequalities in mortality in Sweden and New Zealand. A 20-year gender perspective
BACKGROUND: Both trends in socioeconomic inequalities in mortality, and cross-country comparisons, may give more information about the causes of health inequalities. We analysed trends in socioeconomic differentials by mortality from early 1980s to late 1990s, comparing Sweden with New Zealand. METHODS: The New Zealand Census Mortality Study (NZCMS) consisting of over 2 million individuals and the Swedish Survey of Living Conditions (ULF) comprising over 100, 000 individuals were used for analyses. Education and household income were used as measures of socioeconomic position (SEP). The slope index of inequality (SII) was calculated to estimate absolute inequalities in mortality. Analyses were based on 3–5 year follow-up and limited to individuals aged 25–77 years. Age standardised mortality rates were calculated using the European population standard. RESULTS: Absolute inequalities in mortality on average over the 1980s and 1990s for both men and women by education were similar in Sweden and New Zealand, but by income were greater in Sweden. Comparing trends in absolute inequalities over the 1980s and 1990s, men's absolute inequalities by education decreased by 66% in Sweden and by 17% in New Zealand (p for trend <0.01 in both countries). Women's absolute inequalities by education decreased by 19% in Sweden (p = 0.03) and by 8% in New Zealand (p = 0.53). Men's absolute inequalities by income decreased by 51% in Sweden (p for trend = 0.06), but increased by 16% in New Zealand (p = 0.13). Women's absolute inequalities by income increased in both countries: 12% in Sweden (p = 0.03) and 21% in New Zealand (p = 0.04). CONCLUSION: Trends in socioeconomic inequalities in mortality were clearly most favourable for men in Sweden. Trends also seemed to be more favourable for men than women in New Zealand. Assuming the trends in male inequalities in Sweden were not a statistical chance finding, it is not clear what the substantive reason(s) was for the pronounced decrease. Further gender comparisons are required
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