181 research outputs found

    A preliminary investigation of the potential for thermographic images to influence householders' understanding of home energy consumption

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    This paper explores the potential connections between the thermographic (infrared) imaging of domestic properties and the impact (on energy conservation behaviours) of showing householders infrared images of their homes. Infrared (IR) images, or thermographic imaging, as it has become known has been applied to the investigation of heat losses and other building related phenomena such as moisture penetration of roofs and failures in damp-proofing systems for a number of years. Recently it has been used by a wide range of public and private bodies to demonstrate the heat of a home in a visible format. This suggests a connection between the householder viewing an IR image and engaging in energy conservation behaviour, such as installing insulation. It is hypothesised that information presented in a manner which attracts the attention of the intended audience, being vivid, specific and personal, is more likely to achieve behaviour change (Stern, 1992). In this paper the evidence of the thermal characteristic of the dwelling (as shown within the thermographic image) will be compared with the householder’s reasoning process as prompted by viewing the images. The possible increase in energy saving behaviours and changes in related attitudes leading from this intervention will be investigated. Questions concerning the links between the householder’s reactions to the images and the possibility that this may facilitate a reduction in energy consumption will be discussed

    eViz - Energy Visualisation for Carbon Reduction

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    Predicting Relaxation in Strained Epitaxial Layers

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    Strained epitaxial semiconductor layers, much thicker than the critical thickness, have been used as strain-relief buffer layers for many years. The most successful structure developed so far dates back to the 1960\u27s, and consists of a very thick ( ~30 μm) layer in which the misfit is gradually and continuously increased. These structures relax completely and have a sufficiently low threading dislocation density to allow a device structure to be grown on top. This process requires a very high growth rate to produce the buffer layer in a reasonable time, which is only provided by hydride vapourphase epitaxy. Recently, there has been interest in developing thinner structures using both graded and constant composition buffer layers, which, if successful, would resolve this problem. Here, we consider the mechanisms of strain relaxation, paying special attention to the changes in threading dislocation density and surface roughness that occur during misfit relief. An extensive series of experiments shows that the relaxation of constant composition layers, although not following current theoretical models, does appear to follow a simple empirical law. This result suggests an approach which can be used to predict the state of strain in any epitaxial structure, allowing more efficient strain-relief buffer layers to be designed

    The perceived barriers to the inclusion of rainwater harvesting systems by UK house building companies

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    This work investigates the barriers that exist to deter the implementation of rainwater harvesting into new UK housing. A postal questionnaire was sent to a selection of large, medium and small house-builders distributed across the UK. Questions were asked concerning potential barriers to the inclusion of rainwater harvesting in homes separated into five sections; (1) institutional and regulatory gaps, (2) economic and financial constraints, (3) absence of incentives, (4) lack of information and technical knowledge, and (5) house-builder attitudes. The study concludes that although the knowledge of rainwater systems has increased these barriers are deterring house-builders from installing rainwater harvesting systems in new homes. It is further acknowledged that the implementation of rainwater harvesting will continue to be limited whilst these barriers remain and unless resolved, rainwater harvesting's potential to reduce the consumption of potable water in houses will continue to be limited

    Engaging People with Energy Efficiency: A Randomised Controlled Trial Testing the Effects of Thermal Imaging Visuals in a Letter Communication

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    The study tested the effect of adding visualisations to a communication to engage householders with an energy efficiency programme. External wall insulation is an appropriate way of insulating homes, yet take-up is low. Householders may be unaware of the heat loss from uninsulated walls. In earlier research, seeing thermal images prompted the uptake of simple energy efficiency actions amongst householders. Thermal images were added to a standard letter to visualise heat transfer from a home before and after external wall insulation had been installed. A randomised controlled trial tested three types of letter (standard, standard plus thermal image showing problem, standard plus thermal images showing problem and solution) in 5483 UK households. The target outcome was the rate of telephone enquiries after exposure to the letters. Enquiry rates were low (1.6%) and did not differ between letter type. We discuss the null effect in relation to the target action (external wall insulation), the manner of presentation of the visuals (mass communication, letter through the door) and the ingredients of a persuasive intervention. Findings suggest that taking a key ingredient from an intervention and applying it in a different context may result in the loss of its impact.</jats:p

    Exploring backscattered imaging in low voltage FE-SEM

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    Contrast levels in backscattered SEM images were investigated, utilising stage deceleration for low voltage imaging and also electron energy filtering. Image contrast variations are explained via use of Monte Carlo simulations which can predict the optimum accelerating and filter voltages for imaging complex sample mixtures

    Formation and annihilation of nanocavities during keV ion irradiation of Ge

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    Nanocavities in Ge(111) created by 5 keV Xe ion irradiation are characterized by ex situ transmission electron microscopy and Rutherford backscattering spectrometry. Nanocavities nucleate near the surface and then undergo thermal migration. Nanocavities with average diameter of 10 nm and areal density of 5.1 x 10-3 nm-2 are observed at 773 K, while nanocavities with average diameter of 2.9 nm and areal density of 3.1 x 10-3 nm-2 are observed at 673 K. The estimated Xe gas pressure inside the nanocavities is 0.035 GPa at 773 K, much smaller than the estimated equilibrium pressure 0.38 GPa. This result suggests that the nanocavities grow beyond equilibrium size at 773 K. The nanocavities are annihilated at the surface to form surface pits by the interaction of displacement cascades of keV Xe ions with the nanocavities. These pits are characterized by in situ scanning tunneling microscopy. Pits are created on Ge(111) and Ge(001) at temperatures ~ 523-578 K by keV Xe ions even when less than a bilayer (monolayer) of surface material is removed.Comment: 26 pages, 7 figures, to be published in Physical Review

    CT694 and pgp3 as Serological Tools for Monitoring Trachoma Programs.

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    Defining endpoints for trachoma programs can be a challenge as clinical signs of infection may persist in the absence of detectable bacteria. Antibody-based tests may provide an alternative testing strategy for surveillance during terminal phases of the program. Antibody-based assays, in particular ELISAs, have been shown to be useful to document C. trachomatis genital infections, but have not been explored extensively for ocular C. trachomatis infections. An antibody-based multiplex assay was used to test two C. trachomatis antigens, pgp3 and CT694, for detection of trachoma antibodies in bloodspots from Tanzanian children (n = 160) collected after multiple rounds of mass azithromycin treatment. Using samples from C. trachomatis-positive (by PCR) children from Tanzania (n = 11) and control sera from a non-endemic group of U.S. children (n = 122), IgG responses to both pgp3 and CT694 were determined to be 91% sensitive and 98% specific. Antibody responses of Tanzanian children were analyzed with regard to clinical trachoma, PCR positivity, and age. In general, children with more intense ocular pathology (TF/TI = 2 or most severe) had a higher median antibody response to pgp3 (p = 0.0041) and CT694 (p = 0.0282) than those with normal exams (TF/TI = 0). However, 44% of children with no ocular pathology tested positive for antibody, suggesting prior infection. The median titer of antibody responses for children less than three years of age was significantly lower than those of older children. (p<0.0001 for both antigens). The antibody-based multiplex assay is a sensitive and specific additional tool for evaluating trachoma transmission. The assay can also be expanded to include antigens representing different diseases, allowing for a robust assay for monitoring across NTD programs
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