1,457 research outputs found
Determination and Simulation of the Neutron Spectrum of Nuclear Detonations and Surrogate Sources
This research determined a methodology for characterizing the Fast Beam Facility (FBF) at The Ohio State University Nuclear Reactor Laboratory to test the response of photovoltaic arrays to nuclear weapon radiation. Additionally, this research developed neutron and gamma nuclear weapon output spectra of two environments for comparison to the FBF spectrum. A Bonner sphere spectrometer (BSS), coupled with the unfolding program Maximum Entropy Deconvolution (MAXED), was employed as a means of determining the energy spectrum of neutrons. Using the ISO 8529 americium beryllium (AmBe) source as the a priori default spectrum, MAXED was used to unfold the spectrum of neutrons detected using the BSS from a 500 mCi AmBe source. An MCNP model of the experiment was created with the ISO 8529 spectrum used as the neutron source spectrum. The resulting unfolded neutron spectrum has similar characteristics to the ISO 8529 reference spectrum, with peaks located at 3.1 and 4.7 MeV corresponding to the peaks of the reference spectrum. Spectral deviations from the ISO 8529 reference spectrum caused by low-energy, non-neutron interaction events or neutrons thermalized through interactions in the experimental environment are accounted for in the model and reected in the final unfolded neutron spectrum. Next, the neutron and gamma flux received at a fixed photovoltaic array from two detonation scenarios were modeled with MCNP6: a ground-only and a single building model for various height-of-bursts and yields. Thermalization due to neutron interaction and scattering of gamma rays with environmental materials is observed in the spectrum of resulting radiation incident on the photovoltaic array
How Knowledge, Experience, and Educational Level Influence the Use of Informal and Formal Sources of Home Canning Information
In the research study reported here, West Virginia University Extension educators surveyed the public about their current canning knowledge and practices in 2010. The results showed that educational background and canning experience were the most important factors in understanding how clients seek canning information and the degree to which they preserve foods safely. Home canners primarily use family members as first sources of canning information and consider Extension one of the less important sources of information. Improved marketing efforts are needed to increase canners\u27 understanding of the importance of formal canning sources, especially those offered by Extension programs
False Discovery Rate and Localizing Power
False discovery rate (FDR) is commonly used for correction for multiple testing in neuroimaging studies. However, when using two-tailed tests, making directional inferences about the results can lead to vastly inflated error rate, even approaching 100% in some cases. This happens because FDR only provides weak control over the error rate, meaning that the proportion of error is guaranteed only globally over all tests, not within subsets, such as among those in only one or another direction. Here we consider and evaluate different strategies for FDR control with two-tailed tests, using both synthetic and real imaging data. Approaches that separate the tests by direction of the hypothesis test, or by the direction of the resulting test statistic, more properly control the directional error rate and preserve FDR benefits, albeit with a doubled risk of errors under complete absence of signal. Strategies that combine tests in both directions, or that use simple two-tailed p-values, can lead to invalid directional conclusions, even if these tests remain globally valid. To enable valid thresholding for directional inference, we suggest that imaging software should allow the possibility that the user sets asymmetrical thresholds for the two sides of the statistical map. While FDR continues to be a valid, powerful procedure for multiple testing correction, care is needed when making directional inferences for two-tailed tests, or more broadly, when making any localized inference
Great Expectations: Voluntary Sports Clubs and Their Role in Delivering National Policy for English Sport
“The original publication is available at www.springerlink.com”. Copyright International Society for Third-Sector Research and The Johns Hopkins University. DOI: 10.1007/s11266-009-9095-yVoluntary sports clubs (VSCs) account for about a quarter of all volunteering in England. The volunteers work in a mutual aid, self-production, self-consumption system whose main purpose is identifying and nurturing high-level performers. But the new HMG/Sport England strategies leading to London 2012 expects volunteers to make a major contribution to sustaining and extending participation. The study utilized six focus group sessions with a total of 36 officials and members of 36 clubs across the six counties of Eastern England to assess whether and to what extent government policy objectives can be delivered through the voluntary sector. The study focused on the perceptions and attitudes of club members about being expected to serve public policy and the current pressures they and their clubs face. The results lead the authors to question the appropriateness, sensitivity, and feasibility of current sport policy, particularly the emphasis on VSCs as policy implementers.Peer reviewe
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Process Options Description for Vitrification Flowsheet Model of INEEL Sodium Bearing Waste
The technical information required for the development of a basic steady-state process simulation of the vitrification treatment train of sodium bearing waste (SBW) at Idaho National Engineering and Environmental Laboratory (INEEL) is presented. The objective of the modeling effort is to provide the predictive capability required to optimize an entire treatment train and assess system-wide impacts of local changes at individual unit operations, with the aim of reducing the schedule and cost of future process/facility design efforts. All the information required a priori for engineers to construct and link unit operation modules in a commercial software simulator to represent the alternative treatment trains is presented. The information is of a mid- to high-level nature and consists of the following: (1) a description of twenty-four specific unit operations--their operating conditions and constraints, primary species and key outputs, and the initial modeling approaches that will be used in the first year of the simulation's development; (2) three potential configurations of the unit operations (trains) and their interdependencies via stream connections; and (3) representative stream compositional makeups
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Steady-State Simulation of Steam Reforming of INEEL Tank Farm Waste
A steady-state model of the Sodium-Bearing Waste steam reforming process at the Idaho National Engineering and Environmental Laboratory has been performed using the commercial ASPEN Plus process simulator. The preliminary process configuration and its representation in ASPEN are described. As assessment of the capability of the model to mechanistically predict product stream compositions was made, and fidelity gaps and opportunities for model enhancement were identified, resulting in the following conclusions: (1) Appreciable benefit is derived from using an activity coefficient model for electrolyte solution thermodynamics rather than assuming ideality (unity assumed for all activity coefficients). The concentrations of fifteen percent of the species present in the primary output stream were changed by more than 50%, relative to Electrolyte NRTL, when ideality was assumed; (2) The current baseline model provides a good start for estimating mass balances and performing integrated process optimization because it contains several key species, uses a mechanistic electrolyte thermodynamic model, and is based on a reasonable process configuration; and (3) Appreciable improvement to model fidelity can be realized by expanding the species list and the list of chemical and phase transformations. A path forward is proposed focusing on the use of an improved electrolyte thermodynamic property method, addition of chemical and phase transformations for key species currently absent from the model, and the combination of RGibbs and Flash blocks to simulate simultaneous phase and chemical equilibria in the off-gas treatment train
Enhanced enforcement of the foreign corrupt practices act: Improving the ethics of U.S. business practices abroad
Empirical research demonstrates that bribery has a detrimental impact on investment, economic growth, trade, and democratic governments. In response to rising bribery activity and the additional burdens placed on corporate officials by the Sarbanes-Oxley Act of 2002, enforcement of the Foreign Corrupt Practices Act (FCPA) of 1977 has reached an all-time high. Although many managers, financial officers, entrepreneurs, and auditors are aware of the FCPA\u27s objectives and mandates, many do not do an adequate job of protecting their firms, employees, and/or clients from fines and prison sentences. The purposes of this paper are to (1) analyze and describe bribery and FCPA case filings, sanctions, payments (bribes), and value of business to be obtained; (2) describe and analyze the important provisions of the FCPA; (3) discuss vicarious liability or the liability of U.S. firms and others for the acts of third parties; and (4) make recommendations to help firms improve their compliance with the FCPA. © 2012 by Emerald Group Publishing Limited
Detection of X-rays from the jet-driving Symbiotic Star MWC 560
We report the detection of X-ray emission from the jet-driving symbiotic star
MWC 560. We observed MWC 560 with XMM-Newton for 36 ks. We fitted the spectra
from the EPIC pn, MOS1 and MOS2 instruments with XSPEC and examined the light
curves with the package XRONOS. The spectrum can be fitted with a highly
absorbed hard X-ray component from an optically-thin hot plasma, a Gaussian
emission line with an energy of 6.1 keV and a less absorbed soft thermal
component. The best fit is obtained with a model in which the hot component is
produced by optically thin thermal emission from an isobaric cooling flow with
a maximum temperature of 61 keV, which might be created inside an
optically-thin boundary layer on the surface of the accreting with dwarf. The
derived parameters of the hard component detected in MWC 560 are in good
agreement with similar objects as CH Cyg, SS7317, RT Cru and T CrB, which all
form a new sub-class of symbiotic stars emitting hard X-rays. Our previous
numerical simulations of the jet in MWC 560 showed that it should produce
detectable soft X-ray emission. We infer a temperature of 0.17 keV for the
observed soft component, i.e. less than expected from our models. The total
soft X-ray flux (i.e. at < 3 keV) is more than a factor 100 less than predicted
for the propagating jet soon after its birth (<0.3 yr), but consistent with the
value expected due its decrease with age. The ROSAT upper limit is also
consistent with such a decrease. We find aperiodic or quasi-periodic
variability on timescales of minutes and hours, but no periodic rapid
variability. All results are consistent with an accreting white dwarf powering
the X-ray emission and the existence of an optically-thin boundary layer around
it.Comment: 8 pages, 5 figure, accepted for publication in A &
The lived experience of chronic headache: a systematic review and synthesis of the qualitative literature.
OBJECTIVE: To systematically review the qualitative literature of the lived experience of people with a chronic headache disorder. BACKGROUND: Chronic headaches affect 3%-4% of the population. The most common chronic headache disorders are chronic migraine, chronic tension-type headache and medication overuse headache. We present a systematic review and meta-ethnographic synthesis of the lived experience of people with chronic headache. METHODS: We searched seven electronic databases, hand-searched nine journals and used a modified Critical Appraisal Skills Programme checklist to appraise study quality. Following thematic analysis we synthesised the data using a meta-ethnographic approach. RESULTS: We identified 3586 unique citations; full texts were examined for 86 studies and 4 were included in the review. Included studies differed in their foci: exploring, patient-centred outcomes, chronic headache as a socially invisible disease, psychological processes mediating impaired quality of life, and the process of medication overuse. Initial thematic analysis and subsequent synthesis gave three overarching themes: 'headache as a driver of behaviour' (directly and indirectly), 'the spectre of headache' and 'strained relationships'. CONCLUSION: This meta-synthesis of published qualitative evidence demonstrates that chronic headaches have a profound effect on people's lives, showing similarities with other pain conditions. There were insufficient data to explore the similarities and differences between different chronic headache disorders.National Institute for Health Research Programme Grants for Applied Research (Chronic Headache Education and Self-management Study (CHESS) ISRCTN Number: 79708100)
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