338 research outputs found
Research and development of the dry tape battery concept Quarterly report no. 2, 9 Sep. - 8 Dec. 1965
Magnesium-aluminum chloride, hydrogen chloride- trichlorotriazinetrione system for dry tape batterie
Research and development of the dry tape battery concept Quarterly report no. 1, 9 Jun. - 8 Sep. 1965
Cell discharge measurements for dry tape battery couple - anode and cathode development in aqueous and nonaqueous electrolyte
Scaling behavior of self-avoiding walks on percolation clusters
The scaling behavior of self-avoiding walks (SAWs) on the backbone of
percolation clusters in two, three and four dimensions is studied by Monte
Carlo simulations. We apply the pruned-enriched Rosenbluth chain-growth method
(PERM). Our numerical results bring about the estimates of critical exponents,
governing the scaling laws of disorder averages of the end-to-end distance of
SAW configurations. The effects of finite-size scaling are discussed as well.Comment: 6 page
A Search for Oxygen in the Low-Density Lyman-alpha Forest Using the Sloan Digital Sky Survey
We use 2167 Sloan Digital Sky Survey (SDSS) quasar spectra to search for
low-density oxygen in the Intergalactic Medium (IGM). Oxygen absorption is
detected on a pixel-by-pixel basis by its correlation with Lyman-alpha forest
absorption. We have developed a novel Locally Calibrated Pixel (LCP) search
method that uses adjacent regions of the spectrum to calibrate interlopers and
spectral artifacts, which would otherwise limit the measurement of OVI
absorption. Despite the challenges presented by searching for weak OVI within
the Lyman-alpha forest in spectra of moderate resolution and signal-to-noise,
we find a highly significant detection of absorption by oxygen at 2.7 < z < 3.2
(the null hypothesis has a chi^2=80 for 9 data points).
We interpret our results using synthetic spectra generated from a lognormal
density field assuming a mixed quasar-galaxy photoionizing background (Haardt &
Madau 2001) and that it dominates the ionization fraction of detected OVI. The
LCP search data can be fit by a constant metallicity model with [O/H] =
-2.15_(-0.09)^(+0.07), but also by models in which low-density regions are
unenriched and higher density regions have a higher metallicity. The
density-dependent enrichment model by Aguirre et al. (2008) is also an
acceptable fit. All our successful models have similar mass-weighted oxygen
abundance, corresponding to [_MW] = -2.45+-0.06. This result can be used
to find the cosmic oxygen density in the Lyman-alpha forest, Omega_(Oxy, IGM) =
1.4(+-0.2)x10^(-6) = 3x10^(-4) Omega_b. This is the tightest constraint on the
mass-weighted mean oxygen abundance and the cosmic oxygen density in the
Lyman-alpha forest to date and indicates that it contains approximately 16% of
metals produced by star formation (Bouch\'e et al. 2008) up to z = 3.Comment: 12 pages, 9 figures. Accepted by ApJ (minor changes
Index Construction for Multiple Objective Analysis of Land and Water Use in a High Mountain Watershed
Comprehensive planning is an elusive ideal. The practical planner must sort the relevant information from the vast amounts of data that modern technology can collect. The objective of this study was to use the Upper Blackfoot watershed in the mountains of Southeastern Idaho as an arena for developing methods for construction, refinement, and application of indices needed to design land and water management schemes, compare alternatives, and influence the public in their uses of the area. A total of 21 uses were examined on 242 land units of a 160 square-mile area ranging in elevation from 6300 to 9000 feet and where the principal activities of grazing, lumbering, mining, and recreation can only be undertaken in the summer after the snow has melted. The indices considered were a reasonability index for screening out unreasonable uses at the start of the planning process, an index of use intensity for estimating an amount for reasonable uses, and an index for estimating the utility of the amount of use made from the public viewpoint. Data were collected on 42 attributes for the 343 land units and used in a linear programming model to maximize 1) economic benefits from use of the area and 2) minimize environmental disturbance. The resolution in the available use data limited the model solution to allocating uses among 18 larger land units. The primary factor limiting the modeling, however, was the lack of information for defining the interactions among the uses. The analysis provides a framework for classifying and identifying interactions beginning with the simplest case of simultaneous use by two uses in near proximity. The contribution of the study was a framework for analysis and the identification of the needs for research on the physical interactions among simultaneous uses, the perceived interactions of simultaneous users, and characterization of attributes for defining the quality of an area for a use
Awareness of vaccination status and its predictors among working people in Switzerland
BACKGROUND: Adult vaccination status may be difficult to obtain, often requiring providers to rely on individual patient recall. To determine vaccination status awareness and the sociodemographic predictors of awareness for tetanus, hepatitis A and B, tick born encephalitis (TBE) and influenza vaccination. METHODS: Multivariate analyses were used to evaluate a questionnaire survey of 10 321 employees (4070 women and 6251 men aged 15–72 years) of two companies in Switzerland. RESULTS: Among 10 321 respondents, 75.5% reported knowing their tetanus vaccination status, 64.1% hepatitis A, 61.1% hepatitis B, 64.3% TBE and 71.9% influenza. Between 1 in 4 and 1 in 3 employees were not aware of their vaccination status. Differences in awareness for the five vaccinations considered correlated with gender and language. These differences persisted in multivariate analyses. CONCLUSION: Women employees, German-speaking employees and employees who paid more attention to their diet were more often aware of their vaccination status. A more reliable and readily accessible data source for vaccination status is needed in order to capitalize on opportunities to update vaccinations among Swiss employees
Bisimilarity and refinement for hybrid(ised) logics
The complexity of modern software systems entails the need for reconfiguration mechanisms governing the dynamic evolution of their execution configurations in response to both external stimulus or internal performance measures. Formally, such systems may be represented by transition systems whose nodes correspond to the different configurations they may assume. Therefore, each node is endowed with, for example, an algebra, or a first-order structure, to precisely characterise the semantics of the services provided in the corresponding configuration.
Hybrid logics, which add to the modal description of transition structures the ability to refer to specific states, offer a generic framework to approach the specification and design of this sort of systems. Therefore, the quest for suitable notions of equivalence and refinement between models of hybrid logic specifications becomes fundamental to any design discipline adopting this perspective. This paper contributes to this effort from a distinctive point of view: instead of focussing on a specific hybrid logic, the paper introduces notions of bisimilarity and refinement for hybridised logics, i.e. standard specification logics (e.g. propositional, equational, fuzzy, etc) to which modal and hybrid features were added in a systematic way.FC
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Common Data Elements for COVID-19 Neuroimaging: A GCS-NeuroCOVID Proposal
Funder: National Institute of Neurological Disorders and Stroke; doi: http://dx.doi.org/10.13039/100000065Funder: James S. McDonnell Foundation; doi: http://dx.doi.org/10.13039/100000913Funder: National Institute of Health ResearchFunder: United Kingdom Research and InnovationFunder: Addenbrooke’s Charitable Trus
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