Cladding strategies for building-integrated photovoltaics

Photovoltaic cladding on the surfaces of commercial buildings has the potential for considerable reductions in carbon emissions due to embedded renewable power generation displacing conventional power utilization. In this paper, a model is described for the optimization of photovoltaic cladding densities on commercial building surfaces. The model uses a modified form of the ‘fill factor’ method for photovoltaic power supply coupled to new regression-based procedures for power demand estimation. An optimization is included based on a defined ‘mean index of satisfaction’ for matched power supply and demand (i.e., zero power exportation to the grid). The mean index of satisfaction directly translates to the reduction in carbon emission that might be expected over conventional power use. On clear days throughout the year, reductions of conventional power use of at least 60% can be achieved with an optimum cladding pattern targeted to lighting and small power load demands

Transition between educational sectors and discontinuities of ICT resource and pedagogy

Technologically supported education has introduced benefits but also challenges to the transition across school levels of education. While resolving some traditional issues, these technologies have in some instances created a new set of discontinuities at both the resource and pedagogic level. These discontinuities arise due to variance between primary and secondary school access and practice, and also between pupils' experiences of access and practice at previous institutions. In this paper evidence is presented from interview, questionnaire, and classroom observation data collected from 48 schools during two projects investigating the impact of high-speed Internet access (broadband) in English schools. Findings indicate that schools offer different levels of access to technology, and also different activities when using technology facilities. While differences in practice have always been present across and within levels of education, the introduction of high-speed Internet access has increased the gap between those using the technology as an add-on to existing resources and those embedding the technological facilities into the fabric of the learning environment. A key issue explored is the impact of the discontinuity that occurs when primary (elementary school) education becomes technically richer than partner secondary (high school) institutions

Pose Estimation of Target Satellite for Proximity Operations

Close-proximity operations are increasingly a topic of interest, where satellites manoeuvre within a very small distance of other spacecraft. A high degree of accuracy is required in estimating the relative position and orientation of the other spacecraft, in order to conduct such manoeuvres safely. Traditionally, active systems such as radar or more recently Differential GPS have been used for relative position estimation, yet these give little information on the orientation of the other satellite. Passive imaging can provide a large amount of information on the location and orientation of the Target, with high spatial resolution. Imaging requires only low-powered cameras, which can be made available on a wider range of satellites, and does not require any functionality from the other spacecraft. A robust autonomous close-range relative orientation and location (pose) estimation system is proposed, based on computer vision. Using a single image, and utilising knowledge of the Target spacecraft, an estimation of the Target’s six relative rotation and translation parameters are found from a distance in the order of 10 metres. Such position and rotation estimates over time will allow relative orbit parameter estimation, and enable close-proximity operations such as docking and remote inspection

Methods for the Study of Soil Charcoal as an Indicator of Fire and Forest History in the Appalachian Region, U.S.A.

Charcoal particles in soils and sediments of the Appalachian region provide evidence of long-term fire history relevant to resource management and to studies of paleoclimate, vegetation history, and the effects of prehistoric and historic humans on the environment. Charcoal records of fire history are of low resolution in comparison to dendrochronological records, but reach well beyond the oldest trees in most areas, providing evidence of fires thousands or tens of thousands of years ago. We focus here on fire history reconstruction from soil charcoal, which provides site-specific evidence of past fires and potentially forest composition. Charcoal \u3e 2 mm may be large enough for taxonomic identification, and of sufficient mass to enable AMS radiocarbon dating of individual particles. Soil mixing due to physical and biological factors creates soil profiles in the southern Appalachians in which charcoal age is not predictable from charcoal depth; soil charcoal records thus require many radiocarbon dates

Fermi-Frenet coordinates for space-like curves

We generalize Fermi coordinates, which correspond to an adapted set of coordinates describing the vicinity of an observer's worldline, to the worldsheet of an arbitrary spatial curve in a static spacetime. The spatial coordinate axes are fixed using a covariant Frenet triad so that the metric can be expressed using the curvature and torsion of the spatial curve. As an application of Fermi-Frenet coordinates, we show that they allow covariant inertial forces to be expressed in a simple and physically intuitive way.Comment: 7 page

The impact of broadband in schools

The report reviews evidence for the impact of broadband in English schools, exploring; Variations in provision in level of broadband connectivity; Links between the level of broadband activity and nationally accessible performance data; Aspects of broadband connectivity and the school environment that contribute to better outcomes for pupils and teachers; Academic and motivational benefits associated with educational uses of this technology

Observations of the structure and evolution of solar flares with a soft X-ray telescope

Soft X ray flare events were observed with the S-056 X-ray telescope that was part of the ATM complement of instruments aboard SKYLAB. Analyses of these data are reported. The observations are summarized and a detailed discussion of the X-ray flare structures is presented. The data indicated that soft X-ray emitted by a flare come primarily from an intense well-defined core surrounded by a region of fainter, more diffuse emission. An analysis of flare evolution indicates evidence for preliminary heating and energy release prior to the main phase of the flare. Core features are found to be remarkably stable and retain their shape throughout a flare. Most changes in the overall configuration seem to be result of the appearance, disappearance or change in brightness of individual features, rather than the restructuring or reorientation of these features. Brief comparisons with several theories are presented

Tablet PCs in schools: Case study report: A report for Becta by the Open University

The publication provides an analysis of twelve case studies involving schools in England that were using Tablet PCs. The analysis is complemented by brief individual reports describing aspects of how each of these schools was using Tablet PCs

Screening and diagnostic assessment of neurodevelopmental disorders in a male prison

Purpose The purpose of this paper is to identify neurodevelopmental disorders and difficulties (NDD) in a male prison. The study used standardised tools to carry out screening and diagnostic assessment of the attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and intellectual disability (ID). Design/methodology/approach The ADHD self-report scale, 20-item autism quotient and the Learning Disability Screening Questionnaire were used to screen 240 male prisoners. Prisoners who screened positive on one or more of these scales or self-reported a diagnosis of ADHD, ASD or ID were further assessed using the diagnostic interview for ADHD in adults, adapted Autism Diagnostic Observation Schedule and the Quick Test. Findings Of the 87 prisoners who screened positive for NDD and were further assessed, 70 met the study’s diagnostic criteria for ADHD, ASD or ID. Most of those with NDD (51 per cent) had previously gone unrecognised and a high proportion (51 per cent) were identified through staff- or self-referral to the study. Originality/value The study demonstrated that improving awareness and providing access to skilled, standardised assessment within a male prison can result in increased recognition and identification of NDD

What is required to measure the wear of explanted metal on metal hips?

Abstract INTRODUCTION There is increasing worldwide interest in the assessment of wear in explanted hip components. This is due is part to high profile failures of orthopaedic components in the US, whilst in the UK hip resurfacings have been experiencing a higher than expected failure rate. The reasons for these failures are not well understood, with data from the NJR suggesting the 43% of MoM resurfacing failures are unexplained. Wear analysis is a vital tool in determining failure mechanisms and ultimately improving the longevity of joint replacements through improved design and manufacturing control. There are currently no relevant measurement standards for the evaluation of retrieved orthopaedic components. This paper will assess two of the most commonly used techniques namely roundness measurement and co-ordinate measurement. The advantages and disadvantages of both techniques are considered in this paper. ROUNDNESS MACHINE The Talyrond 365 is a stylus based roundness machine. The component is located on a rotating table and the stylus measures the deviation from a perfect circle as the component is slowly rotated. The Talyrond measures a single profile to an accuracy of 30 nm and up to 72,000 data points per revolution. The air spindle has a radial accuracy of <0.02 μm and the Talymin gauge a minimum resolution of 12 nm. Individual roundness profiles can be stitched together to build up 3D cylinder maps, allowing 3D pictures of sections of explanted hip components to be generated. COORDINATE MEASURING MACHINE Co-ordinate measuring machines (CMMs) have been widely used in manufacturing quality and research departments for a number of years and the CMM is recognised as a powerful and important tool capable of ascertaining geometric data from a component. The CMM used in this study was a Zeiss Prismo CMM (Carl Zeiss Ltd., Rugby, UK) with a probing error of 0.7 μm. Components are securely held in a chuck fixture arrangement and the dimensions of the component in the portion of the bearing that is unworn is ascertained through measurement. The initial measurements are used to produce a reverse engineered 3D CAD surface which represents the component ‘pre-wear’ surface. The surface of the component is then scanned and the deviation from this pre-wear surface is mapped. The maximum linear wear and wear volume are then calculated directly. DISCUSSION The main advantage of CMM and Talyrond is that they are available in most metrology and measurement rooms. The CMM is a particularly versatile machine and can be used to measure any orthopaedic components. There is a need to develop a suitable Standard for both machines detailing a protocol to measure explanted hip and quantify the wear. A study is underway to measure a set of explanted hip components to allow a detailed comparison between of measurements between the Talyrond and CMM. The result of this study will be included in the paper. CONCLUSIONS The CMM and Talyrond are both instruments suited to measuring wear of explanted hips. A full evaluation of the systems and the development of robust measurement protocol and standard would be advantageous to the orthopaedic industry