3,621 research outputs found

    Tackling barriers to take-up of fuel poverty alleviation measures

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    Although there has been much work around the take-up of fuel poverty alleviation programmes carried out this has generally focussed on evidence from frontline managers and other stakeholders. Any investigation with end users has been minimal. Funded by Eaga Partnership Charitable Trust, Sustainable Cities Research Institute carried out a community-based investigation into barriers and possible solutions to the uptake of fuel poverty alleviation programmes. A combination of desk-based research with frontline staff and Participatory Appraisal (PA) techniques with communities were used to carry out this research. 362 people took part in the PA and 17 frontline staff returned detailed questionnaires. 4 areas were studied: 3 with poor and one with good take-up. Additionally vulnerable groups of consumers were identified; elderly, Black and Minority Ethnic (BME) groups and rural consumers. Each of the 3 areas with poor take-up has a good concentration of one of the identified vulnerable groups

    Shuttle orbiter Ku-band radar/communications system design evaluation. Ku band bent-pipe channel performance evaluation

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    Because of difficulties with the bit detector of the SPA mode 1 channel 3 input port, a new bit synchronizer was required. The two prime candidate designs are described and analyzed. The selected design is a modification of one which utilizes a phase frequency detector to track the received data clock frequency and a mid-bit transition point sample detector to generate a bit timing error (phase error) signal to control the relative phase between the local clock and the local data stream. The model used to calculate the effects of cable attenuation and rise time degradation is discussed

    Shuttle orbiter Ku-band radar/communications system design evaluation: High gain antenna/widebeam horn

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    The physical characteristics of the high gain antenna reflector and feed elements are described. Deficiencies in the sum feed are discussed, and lack of atmospheric venting is posed as a potential problem area. The measured RF performance of the high gain antenna is examined and the high sidelobe levels measured are related to the physical characteristics of the antenna. An examination of the attributes of the feed which might be influenced by temperature extremes shows that the antenna should be insensitive to temperature variations. Because the feed support bipod structure is considered a significant contributor to the high sidelobe levels measured in the azimuth plane, pod relocation, material changes, and shaping are suggested as improvements. Alternate feed designs are presented to further improve system performance. The widebeam horn and potential temperature effects due to the polarizer are discussed as well as in the effects of linear polarization on TDRS acquisition, and the effects of circular polarization on radar sidelobe avoidance. The radar detection probability is analyzed as a function of scan overlap and target range

    Engineering evaluations and studies. Report for Ku-band studies, exhibit A

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    System performance aspects of the Ku band radar communication hardware and investigations into the Ku band/payload interfaces are discussed. The communications track problem caused by the excessive signal dynamic range at the servo input was investigated. The management/handover logic is discussed and a simplified description of the transmitter enable logic function is presented. Output noise produced by a voltage-controlled oscillator chip used in the SPA return-link channel 3 mid-bit detector is discussed. The deployed assembly (DA) and EA-2 critical design review data are evaluated. Cross coupling effects on antenna servo stability were examined. A series of meetings on the acceptance test specification for the deployed assembly is summarized

    A new species of phyllopod

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    http://deepblue.lib.umich.edu/bitstream/2027.42/56580/1/OP141.pd

    Regulatory Challenges to Energy Storage Deployment An Overview of the UK Market

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    This working paper investigates how the UK is currently integrating energy storage technologies into its electricity markets, the regulatory barriers it is facing, and how it is responding to these challenges. It was prepared by the ‘Realising Energy Storage Technologies in Low-carbon Energy Systems’ (RESTLESS) project, which is funded by the UK Engineering and Physical Sciences Research Council. The project is part of the EPSRC Energy Superstore Hub and is associated with the UK Energy Research Centre (UKERC). The authors are solely responsible for all of the analysis in this paper. Any views expressed in this paper are the authors’ and have not been endorsed by any of the organisations associated with the RESTLESS project

    Shuttle Ku-band and S-band communications implementation study

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    Various aspects of the shuttle orbiter S-band network communication system, the S-band payload communication system, and the Ku-band communication system are considered. A method is proposed for obtaining more accurate S-band antenna patterns of the actual shuttle orbiter vehicle during flight because the preliminary antenna patterns using mock-ups are not realistic that they do not include the effects of additional appendages such as wings and tail structures. The Ku-band communication system is discussed especially the TDRS antenna pointing accuracy with respect to the orbiter and the modifications required and resulting performance characteristics of the convolutionally encoded high data rate return link to maintain bit synchronizer lock on the ground. The TDRS user constraints on data bit clock jitter and data asymmetry on unbalanced QPSK with noisy phase references are included. The S-band payload communication system study is outlined including the advantages and experimental results of a peak regulator design built and evaluated by Axiomatrix for the bent-pipe link versus the existing RMS-type regulator. The nominal sweep rate for the deep-space transponder of 250 Hz/s, and effects of phase noise on the performance of a communication system are analyzed

    Geometry of River Networks II: Distributions of Component Size and Number

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    The structure of a river network may be seen as a discrete set of nested sub-networks built out of individual stream segments. These network components are assigned an integral stream order via a hierarchical and discrete ordering method. Exponential relationships, known as Horton's laws, between stream order and ensemble-averaged quantities pertaining to network components are observed. We extend these observations to incorporate fluctuations and all higher moments by developing functional relationships between distributions. The relationships determined are drawn from a combination of theoretical analysis, analysis of real river networks including the Mississippi, Amazon and Nile, and numerical simulations on a model of directed, random networks. Underlying distributions of stream segment lengths are identified as exponential. Combinations of these distributions form single-humped distributions with exponential tails, the sums of which are in turn shown to give power law distributions of stream lengths. Distributions of basin area and stream segment frequency are also addressed. The calculations identify a single length-scale as a measure of size fluctuations in network components. This article is the second in a series of three addressing the geometry of river networks.Comment: 16 pages, 13 figures, 4 tables, Revtex4, submitted to PR
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