6,323 research outputs found
Submerged gas injector expels cryogenic liquids from tanks
Vaporizing small portion of cryogenic liquid into pressurizing gas reduces amount of pressurizing gas required to expel cryogenic liquid from tank. Specific example of injecting helium gas, stored at same temperature of liquid hydrogen, through submerged porous plate directly into liquid hydrogen is described
Vibrational States of the Hydrogen Isotopes on Pd(111)
The ground and excited vibrational states for the three hydrogen isotopes on
the Pd(111) surface have been calculated. Notable features of these states are
the high degree of anharmonicity, which is most prominently seen in the weak
isotopic dependence of the parallel vibrational transition, and the narrow
bandwidths of these states, which imply that atomic hydrogen is localized on a
particular surface site on time scales of 100 picoseconds or more. Experiments
to resolve ambiguities concerning the present system are suggested.Comment: Surface Science Letters, 302, L305 (1994
Types of farming in Missouri
Publication authorized April 28, 1938."University of Missouri, Agricultural Experiment Station in cooperation with Bureau of Agricultural Economics, United States Department of Agriculture."Digitized 2007 AES.Includes bibliographical references
Double-Scaling Limit of Heterotic Bundles and Dynamical Deformation in CFT
We consider heterotic string theory on Eguchi-Hanson space, as a local model
of a resolved A_1 singularity in a six-dimensional flux compactification, with
an Abelian gauge bundle turned on and non-zero torsion. We show that in a
suitable double scaling limit, that isolates the physics near the non-vanishing
two-cycle, a worldsheet conformal field theory description can be found. It
contains a heterotic coset whose target space is conformal to Eguchi-Hanson.
Starting from the blow-down limit of the singularity, it can be viewed as a
dynamical deformation of the near-horizon fivebrane background. We analyze in
detail the spectrum of the theory in particular examples, as well as the
important role of worldsheet non-perturbative effects.Comment: 45 pages, no figures; ver2: typos corrected, references added, an
extra tadpole-free model covere
Recommended from our members
Spatial epidemiological patterns suggest mechanisms of land-sea transmission for Sarcocystis neurona in a coastal marine mammal.
Sarcocystis neurona was recognised as an important cause of mortality in southern sea otters (Enhydra lutris nereis) after an outbreak in April 2004 and has since been detected in many marine mammal species in the Northeast Pacific Ocean. Risk of S. neurona exposure in sea otters is associated with consumption of clams and soft-sediment prey and is temporally associated with runoff events. We examined the spatial distribution of S. neurona exposure risk based on serum antibody testing and assessed risk factors for exposure in animals from California, Washington, British Columbia and Alaska. Significant spatial clustering of seropositive animals was observed in California and Washington, compared with British Columbia and Alaska. Adult males were at greatest risk for exposure to S. neurona, and there were strong associations with terrestrial features (wetlands, cropland, high human housing-unit density). In California, habitats containing soft sediment exhibited greater risk than hard substrate or kelp beds. Consuming a diet rich in clams was also associated with increased exposure risk. These findings suggest a transmission pathway analogous to that described for Toxoplasma gondii, with infectious stages traveling in freshwater runoff and being concentrated in particular locations by marine habitat features, ocean physical processes, and invertebrate bioconcentration
Using the Web to Collect Data on Sensitive Behaviours: A Study Looking at Mode Effects on the British National Survey of Sexual Attitudes and Lifestyles.
BACKGROUND: Interviewer-administered surveys are an important method of collecting population-level epidemiological data, but suffer from declining response rates and increasing costs. Web surveys offer more rapid data collection and lower costs. There are concerns, however, about data quality from web surveys. Previous research has largely focused on selection biases, and few have explored measurement differences. This paper aims to assess the extent to which mode affects the responses given by the same respondents at two points in time, providing information on potential measurement error if web surveys are used in the future. METHODS: 527 participants from the third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3), which uses computer assisted personal interview (CAPI) and self-interview (CASI) modes, subsequently responded to identically-worded questions in a web survey. McNemar tests assessed whether within-person differences in responses were at random or indicated a mode effect, i.e. higher reporting of more sensitive responses in one mode. An analysis of pooled responses by generalized estimating equations addressed the impact of gender and question type on change. RESULTS: Only 10% of responses changed between surveys. However mode effects were found for about a third of variables, with higher reporting of sensitive responses more commonly found on the web compared with Natsal-3. CONCLUSIONS: The web appears a promising mode for surveys of sensitive behaviours, most likely as part of a mixed-mode design. Our findings suggest that mode effects may vary by question type and content, and by the particular mix of modes used. Mixed-mode surveys need careful development to understand mode effects and how to account for them
Older people and medication taking behaviour: A review of the literature
Background: Older people represent a sizeable population of the UK. Many older people receive drug treatment for long term conditions. Adherence with medication is therefore an important clinical, financial and resource intensive concern. Objectives: This review aimed to examine patient’s beliefs, perceptions and views in relation to adherence with medication.
Design: A comprehensive search of the literature was undertaken using numerous approaches. The search of revealed 30 research papers. Findings: Articles were initially evaluated using Critical Appraisal Skills Programme principles to identify those relevant to the review. Relevant studies were then subjected to a narrative analysis to assist the development of relevant themes. Four themes were identified; experience of adherence; perceptions and attitudes to medication adherence and non-adherence; patients acceptance of their illness and impact on medication taking behaviour and shared decision making. Conclusions: The findings of this review imply that there is a need for more emphasis on shared decision making between the older patient and the prescriber. Using this approach adherence with medication may improve. There is also a need to develop a standardized measure of medication adherence
- …
