1,342 research outputs found

    To assess the value of satellite photographs in resource evaluation on a national scale

    Get PDF
    The author has identified the following significant results. The limit of resolution on ERTS imagery is normally acknowledged to be about 60 miles although very long features such as roads and railways which are often less than 10 miles long are easily detectable. An example is the north-south road and railway from Lobatse to Francistown. Vegetation growth from winter to summer is readily monitored on false color imagery. The limits of government ranches and special farming areas can be quite accurately ascertained from ERTS imagery. Another aspect to which ERTS imagery lends itself is the location and demarcation of bush fires, many of which were seen on the first imagery which was acquired at the end of the cold, dry season. As a whole, MSS 7 offers maximum reflectance contrast among black and white imagery and is the wavelength used most for interpretation

    To assess the value of satellite photographs in resource evaluation on a national scale

    Get PDF
    The author has identified the following significant results. Small scale ERTS-1 imagery has enabled investigators to study large areas at a time. The imagery appears to confirm a new theory that Archean greenstone belts in NE Botswanna and SW Rhodesia are co-extensive and that these so-called schist relics formerly covered a much wider area than is apparent now. The central parts of the region bounded by the schist relics are believed to have suffered granitization. A remnant of an older drainage system to the southwest of the Okavango Swamps, which seems to have been newly discovered on the imagery, may be an indication of the seismic instability of the region. Even quite small earth movements in the swamps could radically affect the direction of water flow. The imagery has proved successful in showing areas infested by the water weed Salvinia Auriculata in the Chobe and Zambesi rivers. This will be immensely valuable in later surveys on the ground. If the satellite was to have continued working, the imagery would have enabled workers to determine the extent of encroachment of the weed without recourse to field observations

    Studies in the later roman army

    Get PDF
    Not availabl

    From integrated to expedient: an adaptive framework for river basin management in developing countries

    Get PDF
    Water resource management / River basin management / Water allocation / Case studies / Africa South of Sahara / Great Ruaha River Basin

    Psychological, psychophysical, and ergogenic effects of music in swimming

    Get PDF
    OBJECTIVES: Existing work using dry land exercise-related activities has shown that the careful application of music can lead to a range of benefits that include enhanced affect, lower perceived exertion, greater energy efficiency, and faster time trial performances. The purpose of this study was to assess the psychological, psychophysical, and ergogenic effects of asynchronous music in swimming using a mixed-methods approach. DESIGN: A mixed-model design was employed wherein there was a within-subjects factor (two experimental conditions and a control) and a between-subjects factor (gender). The experimental component of the study was supplemented by qualitative data that were analysed using inductive content analysis. METHODS: Twenty six participants (Mage = 20.0 years, age range: 18–23 years) underwent a period of habituation with Speedo Aquabeat MP3 players prior to the experimental phase. They were then administered two experimental trials (motivational and oudeterous music at 130 bpm) and a no-music control, during which they engaged in a 200-m freestyle swimming time trial. RESULTS: Participants swam significantly faster when exposed to either music condition relative to control (p = .022, ηp2=.18). Moreover, the music conditions were associated with higher state motivation (p = .016, ηp2=.15) and more dissociative thoughts (p = .014, ηp2=.16). CONCLUSIONS: Findings supported the hypothesis that the use of asynchronous music during a high-intensity task can have an ergogenic effect; this was in the order of 2% when averaged out across the two experimental conditions. The use of music, regardless of its motivational qualities, resulted in higher self-reported motivation as well as more dissociative thoughts

    Contextually aware intelligent control agents for heterogeneous swarms

    Get PDF
    An emerging challenge in swarm shepherding research is to design effective and efficient artificial intelligence algorithms that maintain simplicity in their decision models, whilst increasing the swarm’s abilities to operate in diverse contexts. We propose a methodology to design a context-aware swarm control intelligent agent (shepherd). We first use swarm metrics to recognise the type of swarm that the shepherd interacts with, then select a suitable parameterisation from its behavioural library for that particular swarm type. The design principle of our methodology is to increase the situation awareness (i.e. contents) of the control agent without sacrificing the low computational cost necessary for efficient swarm control. We demonstrate successful shepherding in both homogeneous and heterogeneous swarms.</p

    Use of suppression subtractive hybridisation to extend our knowledge of genome diversity in Campylobacter jejuni

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Previous studies have sought to identify a link between the distribution of variable genes amongst isolates of <it>Campylobacter jejuni </it>and particular host preferences. The genomic sequence data available currently was obtained using only isolates from human or chicken hosts. In order to identify variable genes present in isolates from alternative host species, five subtractions between <it>C. jejuni </it>isolates from different sources (rabbit, cattle, wild bird) were carried out, designed to assess genomic variability within and between common multilocus sequence type (MLST) clonal complexes (ST-21, ST-42, ST-45 and ST-61).</p> <p>Results</p> <p>The vast majority (97%) of the 195 subtracted sequences identified had a best BLASTX match with a <it>Campylobacter </it>protein. However, there was considerable variation within and between the four clonal complexes included in the subtractions. The distributions of eight variable sequences, including four with putative roles in the use of alternative terminal electron acceptors, amongst a panel of <it>C. jejuni </it>isolates representing diverse sources and STs, were determined.</p> <p>Conclusion</p> <p>There was a clear correlation between clonal complex and the distribution of the metabolic genes. In contrast, there was no evidence to support the hypothesis that the distribution of such genes may be related to host preference. The other variable genes studied were also generally distributed according to MLST type. Thus, we found little evidence for widespread horizontal gene transfer between clonal complexes involving these genes.</p

    Hyperspectral imaging based detection of PVC during Sellafield repackaging procedures.

    Get PDF
    Traditionally, Special Nuclear Material (SNM) at Sellafield has been stored in multi-layered packages, consisting of metallic cans and an over-layer of plasticized Polyvinyl Chloride (PVC) as an intermediate layer when transitioning between areas of different radiological classification. However, it has been found that plasticized PVC can break down in the presence of both radiation and heat, releasing hydrochloric acid which can corrode these metallic containers. Therefore, internal repackaging procedures at Sellafield have focused recently on the removal of these PVC films from containers, where as much degraded and often adhered PVC as possible is manually removed based on visual inspection. This manual operation is time-consuming and it is possible that residual fragments of PVC could remain, leading to corrosion-related issues in future. In this work, Hyperspectral Imaging (HSI) was evaluated as a new tool for detecting PVC on metallic surfaces. Samples of stainless steel type 1.4404 – also known as 316L, the same as is used to construct SNM cans – and PVC were imaged in our experiments, and Support Vector Machine (SVM) classification models were used to generate detection maps. In these maps, pixels were classified into either PVC or 316L based on their spectral responses in the range 954-1700nm of the electromagnetic spectrum. Results suggest that HSI could be used for an effective automated detection and quantification of PVC during repackaging procedures, detection and quantification that could be extended to other similar applications
    • …
    corecore