21,046 research outputs found

    Evidence to the House of Lords select committee on science and technology: energy efficient buildings

    Get PDF

    A nanoradian differential VLBI tracking demonstration

    Get PDF
    The shift due to Jovian gravitational deflection in the apparent angular position of the radio source P 0201+113 was measured with very long baseline interferometry (VLBI) to demonstrate a differential angular tracking technique with nanoradian accuracy. The raypath of the radio source P 0201+113 passed within 1 mrad of Jupiter (approximately 10 Jovian radii) on 21 Mar. 1988. Its angular position was measured 10 times over 4 hours on that date, with a similar measurement set on 2 Apr. 1988, to track the differential angular gravitational deflection of the raypath. According to general relativity, the expected gravitational bend of the raypath averaged over the duration of the March experiment was approximately 1.45 nrad projected onto the two California-Australia baselines over which it was measured. Measurement accuracies on the order of 0.78 nrad were obtained for each of the ten differential measurements. The chi(exp 2) per degree of freedom of the data for the hypothesis of general relativity was 0.6, which suggests that the modeled dominant errors due to system noise and tropospheric fluctuations fully accounted for the scatter in the measured angular deflections. The chi(exp 2) per degree of freedom for the hypothesis of no gravitational deflection by Jupiter was 4.1, which rejects the no-deflection hypothesis with greater than 99.999 percent confidence. The system noise contributed about 0.34 nrad per combined-baseline differential measurement and tropospheric fluctuations contributed about 0.70 nrad. Unmodeled errors were assessed, which could potentially increase the 0.78 nrad error by about 8 percent. The above chi(exp 2) values, which result from the full accounting of errors, suggest that the nanoradian gravitational deflection signature was successfully tracked

    How to support growth with less energy

    Get PDF
    There is considerable potential to support growth with less use of primary energy and lower carbon emissions. This can be achieved through technical solutions (existing and new), as well as behavioural change. The goal of securing growth with lower carbon emissions is just one of several strategic goals that need to be satisfied. Of the others, the need to develop alternatives to an energy system heavily dependent on oil and natural gas and to maintain security of energy supply are likely to be the most important. The strategic goals are to achieve major reductions in the energy intensity of transport, buildings in use, and to achieve corresponding reductions in energy intensity of the major building materials. Key challenges associated with these strategic goals include: • the development of technologies to produce carbon-free cement, carbon-free steel, carbon-free glass • enabling infrastructural developments that provide a framework for a wide range of low-carbon technologies and increase energy diversity and security of supply • identification of key energy-efficiency tipping points and the construction of technology policy • development of methane-fired modular fuel cells • improved capabilities to model whole energy systems, i.e. adequately modelling both demand and supply, social/economic as well as technical, and assessing the impact outside of the UK system boundary • better low-carbon planning and improved co-ordination of planning, building control and other policy tools • better monitoring and feedback on the real performance of energy efficient technologies. The implication of the Energy White Paper goal of reducing CO2 emissions by 60% by 2050 is a six-fold reduction in the carbon intensity of the UK economy. In the longer run, it is clear that we will move towards a carbon-free economy. Within this transition, developments in supply, distribution and end-use technologies will be multiplicative, while action to constrain demand growth is crucial to the rate of the overall transition

    Ages of the Pliocene-Pleistocene Alexandra and Ngatutura Volcanics, western North Island, New Zealand, and some geological implications

    Get PDF
    The Alexandra and Ngatutura Volcanics are the two southernmost of the Pliocene-Quaternary volcanic fields of western and northern North Island, New Zealand, northwest of Taupo Volcanic Zone TVZ. The Ngatutura Basalts are an alkalic basaltic field comprising monogenetic volcanoes. The Alexandra Volcanics consist of three basaltic magma series: an alkalic (Okete Volcanics), calcalkalic (Karioi, Pirongia, Kakepuku, and Te Kawa Volcanics), and a minor potassic series. Twenty new K-Arages are presented for the Alexandra Volcanics and 9 new ages for the Ngatutura Basalts. Ages of the Alexandra Volcanics range from 2.74 to 1 .60 Ma, and the ages of all three magma series overlap. Ages of the Ngatutura Basalts range from 1 .83 to 1.54 Ma. Each basaltic field has a restricted time range and there is a progressive younging in age of the basaltic fields of western North Island from the Alexandra Volcanics in the south, to Ngatutura, to South Auckland, and then to the Auckland field in the north. Neither of the Alexandra nor Ngatutura Volcanics shows any younging direction of their volcanic centres or any age pattern within their fields, and there is no systematic variation in age with rock composition. Any correlation of age with degree of erosion of volcanic cones is invalid for these basaltic fields; instead, the degree of erosion may be controlled by the lithology of the cones and possibly by the extent of preservation offered by the thick cover deposits of the Kauroa, Hamilton, and younger tephra beds. Stratigraphic relations have enabled the earliest member of the Kauroa Ash Formation to be dated at 2.3 Ma. This formation represents a series of widespread rhyolitic plinian and ignimbrite eruptions probably derived from TVZ and initiated during the Late Pliocene

    The case for joined-up research on carbon emissions from the building stock: adding value to household and building energy datasets

    Get PDF
    To reach UK objectives for reducing carbon emissions, it is argued that joined-up research on energy use in buildings is essential to develop and support government policy initiatives. The performance based approach introduced in Part-L of the 2006 Building Regulations has further underlined the role of coordinated research to monitor their effectiveness and provide feedback for subsequent revisions. Unfortunately, differences in dwelling classifications systems used in major household surveys currently hinder much of the supporting analysis that might improve SAP and other energy models. The Carbon Reduction in Buildings project has begun a process of integrating or organising existing building energy datasets into a coherent structure for the domestic sector. In addition, it is proposed to archive these for researchers via a building data repository that would facilitate joined-up research more widely

    Milton Keynes Park Revisited: changes in internal temperatures

    Get PDF
    27-30 April 2006 The Carbon Reduction in Buildings project has undertaken a pilot longitudinal survey based on a study of 160 ‘low-energy’ homes in 1989 in Milton Keynes Energy Park. In that study, a sub-sample of 29 dwellings was monitored on an hourly basis for internal temperature for the living room and main bedroom over 2 years. The follow up study has been in progress since 2005 and consists of 15 dwellings from the original detailed survey. Findings include that under an average daily external temperature of 5 ºC, internal temperatures were predicted from regression analysis to be 20.1ºC (95%CI:19.7, 20.5) for the living room in 2005 and 19.5 ºC (95 %CI:19.1, 19.9) for the bedroom. This was not significantly different from the 1990 baseline study, except for main bedroom evening temperatures (6pm-11pm) which were found to have decreased by -1.3°C (95%CI -2.4, 0.08; p-value 0.04). This may be indicative of higher ventilation rates since almost all participants in 2005 reported opening bedroom windows through winter

    No Lambda oscillations

    Full text link
    We examine a recently published calculation which predicts an oscillatory behaviour for the decay of Lambdas produced together with a neutral kaon, and proposes a new expression for the wavelength of kaon strangeness oscillations. We modify the calculation by imposing the requirement that the interference of the K_L and K_S components of the kaon wave function occurs at a specific space-time point. With this requirement, the unusual results predicted vanish, and the conventional results are recovered.Comment: 9 pages Latex, no figures. Added Latex section omitted befor

    Object Matching in Distributed Video Surveillance Systems by LDA-Based Appearance Descriptors

    Full text link
    Establishing correspondences among object instances is still challenging in multi-camera surveillance systems, especially when the cameras’ fields of view are non-overlapping. Spatiotemporal constraints can help in solving the correspondence problem but still leave a wide margin of uncertainty. One way to reduce this uncertainty is to use appearance information about the moving objects in the site. In this paper we present the preliminary results of a new method that can capture salient appearance characteristics at each camera node in the network. A Latent Dirichlet Allocation (LDA) model is created and maintained at each node in the camera network. Each object is encoded in terms of the LDA bag-of-words model for appearance. The encoded appearance is then used to establish probable matching across cameras. Preliminary experiments are conducted on a dataset of 20 individuals and comparison against Madden’s I-MCHR is reported
    corecore