19,127 research outputs found
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Sustainable energy: choices, problems and opportunities
About the Book: The world's dependence on fossil fuels is widely acknowledged to be a major cause of rising levels of carbon dioxide in the atmosphere. Thus there is an urgent need to develop energy sources with lower environmental impact, with attention focusing on renewable energy sources. Concise, authoritative, up-to-date and readable, this book reviews various energy technologies, as well as taking a critical look at the political, social and economic aspects. Throughout, the emphasis is on renewable energy sources (wind, wave, solar, biomass, etc), but a discussion of fossil fuels and nuclear power is also presented. This timely book, written by recognised experts, will be welcomed by those in the energy industries as well as by policy-makers, consultants and engineers. Students and lecturers will also find the material invaluable
Causal Factors, Causal Inference, Causal Explanation
There are two concepts of causes, property causation and token causation. The principle I want to discuss describes an epistemological connection between the two concepts, which I call the Connecting Principle. The rough idea is that if a token event of type Cis followed by a token event of type E, then the support of the hypothesis that the first event token caused the second increases as the strength of the property causal relation of C to E does. I demonstrate the principle, illustrate its application to phylogenies, infections, and rumours, and discuss its consequence for the conceptual distinctness of causal processes from the events they connect. Although I am by no means confident that the Connecting Principle is ultimately correct, it seems to be a useful point of departure into an important aspect of the epistemology of causality
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Comparing support for renewable power
Renewable Energy technology is developing rapidly around the world aided by range of economic support mechanisms. This paper reviews the various mechanisms, and explores the relative merits of technology push and market pull approaches. It compares the approaches adopted in the UK with those used elsewhere
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The Contact Lens Impact on Quality of Life (CLIQ) questionnaire: development and validation
NoPURPOSE. To develop and validate a questionnaire for the measurement of the impact of contact lenses on quality of life (QoL): The Contact Lens Impact on Quality of Life (CLIQ) Questionnaire. METHODS. The questionnaire was developed and validated using conventional methods and Rasch analysis to assure content validity, repeatability, construct validity, and low respondent burden. Item identification and selection (647 items) were performed with an extensive literature review, professional advice, and lay focus groups. Item reduction used focus groups and data obtained from 161 subjects completing a 90-item pilot questionnaire. Validity and reliability, from data of 128 additional subjects, were assessed using Rasch analysis, intraclass correlation coefficient, and Bland-Altman limits of agreement. RESULTS. A 28-item CLIQ Questionnaire was developed and shown to have good validity and reliability by Rasch analysis statistics: real person separation, 2.02; model person separation, 2.17; reliability, 0.80; root mean square measurement error, 2.73; mean square ± SD infit, 1.01 ± 0.18; outfit, 1.01 ± 0.19. The items (mean score, 49.8 ± 4.9) were well targeted to the subjects (mean score, 51.2 ± 6.2) with a mean difference of 1.35 (scale range, 0-100) units. Test-retest intraclass correlation coefficient (0.86) and coefficient of repeatability (±8.00 units) demonstrated good repeatability. CONCLUSIONS. Rasch analysis and standard psychometric analyses demonstrated that the 28-item CLIQ Questionnaire is a valid and reliable measure of QoL in contact lens wearers. A scoring algorithm is provided for CLIQ Questionnaire users to convert raw scores into the Rasch analysis-derived linear person measures
Radiation pressure detection and density estimate for 2011 MD
We present our astrometric observations of the small near-Earth object
2011~MD (), obtained after its very close fly-by to Earth in June
2011. Our set of observations extends the observational arc to days, and
together with the published astrometry obtained around the Earth fly-by allows
a direct detection of the effect of radiation pressure on the object, with a
confidence of . The detection can be used to put constraints on the
density of the object, pointing to either an unexpectedly low value of \rho =
(640 \pm 330) \mbox{ kg} / \mbox{m} ^3 ( confidence interval) if we
assume a typical probability distribution for the unknown albedo, or to an
unusually high reflectivity of its surface. This result may have important
implications both in terms of impact hazard from small objects and in light of
a possible retrieval of this target.Comment: Submitted to ApJ Letter
Regional and Racial Variation in Health Care Among Medicare Beneficiaries
Focuses on variations in healthcare delivery and outcomes among and within hospital service areas, in addition to racial and geographic disparities, as measured by five indicators. Discusses variations in spending and considers implications for reform
A proposed framework for managing environmental causes and consequences of ocean traffic and ports
Paper presented at European Decision Sciences Institute (ED2016), 7th Annual Conference, 24th to 27th May 2016, Helsinki. Abstract The cumulative and in-combination effects of ocean shipping and port operations need addressing via a detailed, rigorous and holistic framework of risk assessment and risk management. This aims to protect the natural system while at the same time obtaining societal benefits from the seas. This paper proposes a conceptual framework that integrates both an ISO industry standard risk assessment and management framework (Bow-tie analysis) and the DAPSI(W)R(M) analysis supported by the ten-tenets criteria to provide guidance for all stakeholders, including industry and government, to address these issues. Water pollution stemming from maritime logistics and SCM are used to illustrate this framework
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