376 research outputs found
The contemporary landscape of fuel poverty research
A key aim of this special issue has been to showcase the breadth of approaches to fuel poverty research emanating from a growing international community of fuel poverty researchers and in doing so, to promote awareness of the range of disciplinary areas influencing contemporary fuel poverty research. Overcoming established disciplinary and methodological siloes represents a considerable challenge for the future of the field and may be key to offering those in policy and practice the clarity and comprehensive insights that they need to fully understand and respond effectively to the problem
Differentials in the homological homotopy fixed point spectral sequence
We analyze in homological terms the homotopy fixed point spectrum of a
T-equivariant commutative S-algebra R. There is a homological homotopy fixed
point spectral sequence with E^2_{s,t} = H^{-s}_{gp}(T; H_t(R; F_p)),
converging conditionally to the continuous homology H^c_{s+t}(R^{hT}; F_p) of
the homotopy fixed point spectrum. We show that there are Dyer-Lashof
operations beta^epsilon Q^i acting on this algebra spectral sequence, and that
its differentials are completely determined by those originating on the
vertical axis. More surprisingly, we show that for each class x in the
$^{2r}-term of the spectral sequence there are 2r other classes in the
E^{2r}-term (obtained mostly by Dyer-Lashof operations on x) that are infinite
cycles, i.e., survive to the E^infty-term. We apply this to completely
determine the differentials in the homological homotopy fixed point spectral
sequences for the topological Hochschild homology spectra R = THH(B) of many
S-algebras, including B = MU, BP, ku, ko and tmf. Similar results apply for all
finite subgroups C of T, and for the Tate- and homotopy orbit spectral
sequences. This work is part of a homological approach to calculating
topological cyclic homology and algebraic K-theory of commutative S-algebras.Comment: Published by Algebraic and Geometric Topology at
http://www.maths.warwick.ac.uk/agt/AGTVol5/agt-5-27.abs.htm
Evaluation of modelled spatially distributed predictions of soil erosion by water versus field-based assessments
Policy makers concerned about soil erosion and its impacts need good quality information on which to base their decisions. There is a trend toward using erosion models to aid such decision making. Such models are based on data obtained from experimental plots. The theoretical results need to be compared with information gained from monitoring erosion in the field to assess if theory accords with reality. Data from the Minimum Information Requirement version of the Water Erosion Prediction Project model (MIRSED) are compared to information gained from field monitoring over a 5-year period (1982–1986) in 11 localities widely spread throughout England and Wales. Two of the localities, Gwent and Shropshire, are examined in detail. The model seriously over predicts erosion, both in amount and extent. Also, the statistical distributions of the data values are different. The model predicts erosion will happen where it does not. The reasons why the two assessments of erosion differ greatly are explored. This comparison shows there is an urgent need to develop models which incorporate information gained from field-based observations. Until better models are devised, policy makers and decision takers should treat the results of modelling exercises with great caution
Southeast Nebraska Geology: Field Trip 3
The purpose of this trip is to familiarize you with the latest Pennsylvanian and earliest Permian rocks that are exposed in extreme southeastern Nebraska. You will see eight exposures of these rocks and will have ample opportunity to collect lithologic samples, as well as samples for both macro- and micro-fossils. The stops have been selected to show you examples of several different environments that existed in southeastern Nebraska in the late Paleozoic. These include subaerial deposits with paleosols, nearshore and offshore marine clastic and carbonate sequences. Each stop is covered in detail in the handouts that have been furnished to the trip participants. Subsequent readers will be able to find this information in the several references that are listed at the end of the text. All of the stops will be in Richardson and Pawnee counties (fig. 1)
Mapping target signatures via partial unmixing of AVIRIS data
A complete spectral unmixing of a complicated AVIRIS scene may not always be possible or even desired. High quality data of spectrally complex areas are very high dimensional and are consequently difficult to fully unravel. Partial unmixing provides a method of solving only that fraction of the data inversion problem that directly relates to the specific goals of the investigation. Many applications of imaging spectrometry can be cast in the form of the following question: 'Are my target signatures present in the scene, and if so, how much of each target material is present in each pixel?' This is a partial unmixing problem. The number of unmixing endmembers is one greater than the number of spectrally defined target materials. The one additional endmember can be thought of as the composite of all the other scene materials, or 'everything else'. Several workers have proposed partial unmixing schemes for imaging spectrometry data, but each has significant limitations for operational application. The low probability detection methods described by Farrand and Harsanyi and the foreground-background method of Smith et al are both examples of such partial unmixing strategies. The new method presented here builds on these innovative analysis concepts, combining their different positive attributes while attempting to circumvent their limitations. This new method partially unmixes AVIRIS data, mapping apparent target abundances, in the presence of an arbitrary and unknown spectrally mixed background. It permits the target materials to be present in abundances that drive significant portions of the scene covariance. Furthermore it does not require a priori knowledge of the background material spectral signatures. The challenge is to find the proper projection of the data that hides the background variance while simultaneously maximizing the variance amongst the targets
The Effect of Time Variation in the Higgs Vacuum Expectation Value on the Cosmic Microwave Background
A time variation in the Higgs vacuum expectation value alters the electron
mass and thereby changes the ionization history of the universe. This change
produces a measurable imprint on the pattern of cosmic microwave background
(CMB) fluctuations. The nuclear masses and nuclear binding energies, as well as
the Fermi coupling constant, are also altered, with negligible impact on the
CMB. We calculate the changes in the spectrum of the CMB fluctuations as a
function of the change in the electron mass. We find that future CMB
experiments could be sensitive to |\Delta m_e/m_e| \sim |\Delta G_F/G_F| \sim
10^{-2} - 10^{-3}. However, we also show that a change in the electron mass is
nearly, but not exactly, degenerate with a change in the fine-structure
constant. If both the electron mass and the fine-structure constant are
time-varying, the corresponding CMB limits are much weaker, particularly for l
< 1000.Comment: 6 pages, 3 figures, Fig. 3 modified, other minor correction
Summary Report of the INL-JISEA Workshop on Nuclear Hybrud Energy Systems
Hybrid energy systems utilize two or more energy resources as inputs to two or more physically coupled subsystems to produce one or more energy commodities as outputs. Nuclear hybrid energy systems can be used to provide load-following electrical power to match diurnal to seasonal-scale changes in power demand or to compensate for the variability of renewable wind or solar generation. To maintain economical, full rate operation of the nuclear reactor, its thermal energy available when power demand is low could be diverted into making synthetic vehicle fuels of various types. The Institute for Nuclear Energy Science and Technology (INEST) and the Joint Institute for Strategic Energy Analysis (JISEA) co-sponsored an international workshop to identify research topics important in advancing the potential use of hybrid systems with a specific focus on nuclear-renewable hybrid systems. The workshop included presentations ranging from energy challenges and research and development (R&D) directions being pursued by nations to multiple options for hybrid systems. Those options include one that is being commercialized to other opportunities and analysis results quantifying them. The workshop also involved two breakout sessions - one focused on thermal energy management issues especially at unit-operation scale and the second focused on system operations issues including system controls, regulatory issues, technical and economic analysis, and market challenges. A discussion involving the full group focused on more general issues such as societal involvement and participation. Key criteria for selecting hybrid energy system projects and metrics for comparing them were also identified by the full group. The workshop's findings are being used initially by INEST to define topics for a research preproposal solicitation
Delivering energy efficiency and carbon reduction schemes in England: Lessons from Green Deal Pioneer Places
Against a background of growing international and national carbon reduction legislation, the UK government introduced the “Green Deal” to deliver a significant increase in housing energy efficiency and reduction in carbon emissions. This paper reflects on one English local authority's experience delivering a programme intended to foster local interest in the Green Deal. Drawing on social surveys and pre and post Green Deal intervention interviews with five demonstrator homes (households that applied to receive a Green Deal package fully funded by the scheme, providing a test bed for the Green Deal recruitment and installation process), this paper shows that awareness and understanding of the Green Deal scheme is low. There is opposition to the cost of finance offered but a strong interest in improving household warmth and for funding improvements through payments added to the electricity bill. Demonstrator home residents perceived Green Deals had improved the warmth and quality of their home, but saving money was the primary motivator for their involvement, not increasing warmth. Whilst Green Deal has not delivered the level of success that was hoped, much can be learned from the scheme to improve future energy efficiency schemes that will be necessary to deliver emission reduction commitments
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