35,988 research outputs found

    Accurate nine-decade temperature-compensated logarithmic amplifier

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    Transistor-driven temperature-stable amplifier with logarithmic operating characteristics permits presentation of the entire range of the reactor without range switching. This circuit is capable of monitoring ion chamber currents over spans of 8 or 9 decades and is used in nuclear reactor instrumentation. Application is found in materials under ultrahigh vacuum

    An investigation on the effect of driver style and driving events on energy demand of a PHEV

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    Environmental concerns, security of fuel supply and CO2 regulations are driving innovation in the automotive industry towards electric and hybrid electric vehicles. The fuel economy and emission performance of hybrid electric vehicles (HEVs) strongly depends on the energy management system (EMS). Prior knowledge of driving information could be used to enhance the performance of a HEV. However, how the necessary information can be obtained to use in EMS optimisation still remains a challenge. In this paper the effect of driver style and driving events like city and highway driving on plug in hybrid electric vehicle (PHEV) energy demand is studied. Using real world driving data from three drivers of very different driver style, a simulation has been exercised for a given route having city and highway driving. Driver style and driving events both affect vehicle energy demand. In both driving events considered, vehicle energy demand is different due to driver styles. The major part of city driving is reactive driving influenced by external factors and driver leading to variation in vehicle speed and hence energy demand. In free highway driving, the driver choice of cruise speed is the only factor affecting vehicle energy demand

    Oral health awareness and care preferences in patients with diabetes : a qualitative study

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    Background People with type 2 diabetes have an increased risk of oral health problems; however, oral health is currently not included in structured diabetes reviews and education in the UK. Aim and Objectives This study explores the patient experience related to oral health and diabetes, especially in relation to: • Awareness of the link between oral health and diabetes and oral self care needs • Interaction with health professionals in dental and general practice • Preferences for receiving oral health information and education Methods This nested qualitative study involved semi-structured telephone interviews with a purposive sample of 20 participants from a questionnaire study on oral health awareness in patients with diabetes. Interview transcripts were analysed using a thematic framework approach. Results Participants were mostly unaware of the link between oral health and diabetes. Those that had been made aware by a health professional were not given concrete self care advice. Interactions with dental professionals were often limited to informing the dental practice of their diagnosis and current medication. Most participants were in favour of dentists screening for diabetes, but as their general practice was the hub for diabetes care, they felt GPs or nurses should provide oral health information and discuss oral health with patients. Conclusions Written information regarding diabetes and its possible effects on oral health needs to be more readily available to people with diabetes, especially at diagnosis. There may be a place for introducing a structured oral health question in routine diabetes reviews

    OPTIMAL HOG SLAUGHTER WEIGHTS UNDER ALTERNATIVE PRICING SYSTEMS

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    Three hog genotypes are simulated to determine how producer profits, economically optimal slaughter weights, and carcass component weights change under three pricing models. Live weight pricing pays more for the fatter barrows whereas a three component (separate payments for fat, lean, and byproducts) and six component (separate payments for major primal cuts, other lean, fat, and byproducts) pricing system pay more for the leaner gilts. Implications for selection of genetic stock and pricing system are presented.Swine production management, Hog pricing systems, Hog marketing, Livestock Production/Industries,

    Development of a Thomson X-ray Polarimeter

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    We describe the current status of the design and development of a Thomson X-ray polarimeter suitable for a small satellite mission. Currently we are considering two detector geometries, one using rectangular detectors placed on four sides of a scattering element and the other using a single cylindrical detector with the scattering element at the center. The rectangular detector configuration has been fabricated and tested. The cylindrical detector is currently under fabrication. In order to compensate any pointing offset of the satellite, a collimator with a flat topped response has been developed that provides a constant effective area over an angular range. We have also developed a double crystal monochromator/polariser for the purpose of test and calibration of the polarimeter. Preliminary test results from the developmental activities are presented here.Comment: 4 pages, 5 figures, in "X-ray Polarimetry: A New Window in Astrophysics", edited by R. Bellazzini, E. Costa, G. Matt and G. Tagliaferri, Cambridge University Press (proceedings of "The Coming of Age of X-ray Polarimetry," Rome, Italy, April 27-30, 2009

    Phase-slip avalanches in the superflow of 4^4He through arrays of nanopores

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    Recent experiments by Sato et al. [1] have explored the dynamics of 4^4He superflow through an array of nanopores. These experiments have found that, as the temperature is lowered, phase-slippage in the pores changes its character, from synchronous to asynchronous. Inspired by these experiments, we construct a model to address the characteristics of phase-slippage in superflow through nanopore arrays. We focus on the low-temperature regime, in which the current-phase relation for a single pore is linear, and thermal fluctuations may be neglected. Our model incorporates two basic ingredients: (1) each pore has its own random value of critical velocity (due, e.g., to atomic-scale imperfections), and (2) an effective inter-pore coupling, mediated through the bulk superfluid. The inter-pore coupling tends to cause neighbours of a pore that has already phase-slipped also to phase-slip; this process may cascade, creating an avalanche of synchronously slipping phases. As the temperature is lowered, the distribution of critical velocities is expected to effectively broaden, owing to the reduction in the superfluid healing length, leading to a loss of synchronicity in phase-slippage. Furthermore, we find that competition between the strength of the disorder in the critical velocities and the strength of the inter-pore interaction leads to a phase transition between non-avalanching and avalanching regimes of phase-slippage. [1] Sato, Y., Hoskinson, E. Packard, R. E. cond-mat/0605660.Comment: 8 pages, 5 figure

    Ground-state properties of a supersymmetric fermion chain

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    We analyze the ground state of a strongly interacting fermion chain with a supersymmetry. We conjecture a number of exact results, such as a hidden duality between weak and strong couplings. By exploiting a scale free property of the perturbative expansions, we find exact expressions for the order parameters, yielding the critical exponents. We show that the ground state of this fermion chain and another model in the same universality class, the XYZ chain along a line of couplings, are both written in terms of the same polynomials. We demonstrate this explicitly for up to N = 24 sites, and provide consistency checks for large N. These polynomials satisfy a recursion relation related to the Painlev\'e VI differential equation, and using a scale-free property of these polynomials, we derive a simple and exact formula for their limit as N goes to infinity.Comment: v2: added more information on scaling function, fixed typo

    Giant Manta Ray, Manta birostris landed at Neendakara Fisheries Harbour

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    Manta rays that belongs to the family Mobulidae occurs in tropical, sub-tropical and temperate waters of the Atlantic, Pacific and Indian Oceans. A large Giant manta ray, Manta birostris (Walbaum, 1792) was landed at Needakara Fisheries Harbour on 12.05.2015. The ray was 370 cm in length and weighed 1100 kg. The information collected from the fishermen indicated that it was incidentally caught in a 12 m OAL outboard (9.9 hp x 2 engines) gillnet unit. The drift gill net called Ozhukkuvala (70-80 mm mesh size, 200 m long) was operated at about 44 m depths. Along with the manta ray, Coryphaena hippurus, Istiophorus platypterus, Scomberomorus commerson, Mobula spp. and Auxis thazard were also landed

    The Blob Algebra and the Periodic Temperley-Lieb Algebra

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    We determine the structure of two variations on the Temperley-Lieb algebra, both used for dealing with special kinds of boundary conditions in statistical mechanics models. The first is a new algebra, the `blob' algebra (the reason for the name will become obvious shortly!). We determine both the generic and all the exceptional structures for this two parameter algebra. The second is the periodic Temperley-Lieb algebra. The generic structure and part of the exceptional structure of this algebra have already been studied. Here we complete the analysis, using results from the study of the blob algebra.Comment: 12 page
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