48,140 research outputs found

    Thermocouple assembly Patent

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    Design and characteristics of thermocouples consisting of flexible tape for improved attachment to temperature sourc

    Retrofit energy conservation in residential buildings in southern California

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    The common energy conservation techniques (ECTs) that can be retrofit-installed into residential buildings are surveyed. The quantity of saved energy for heating and cooling attributable to each ECT is evaluated for three common modes of heating: natural gas heating at 60/therm; heating via heat pump at 1.20/therm;andelectricresistanceheatingat1.20/therm; and electric resistance heating at 2.40/therm. In every case, a life cycle cost comparison is made between the long term revenue due to energy conservation and a safe and conventional alternative investment that might be available to the prudent homeowner. The comparison between investment in an ECT and the alternative investment is brought into perspective using the life cycle payback period and an economic Figure of Merit (FOM). The FOM allows for relative ranking between candidate ECTs. Because the entire spectrum of winter heating climates in California is surveyed, the decision maker can determine whether or not a considered ECT is recommended in a given climate, and under what conditions an ECT investment becomes attractive

    The Extraordinary Infrared Spectrum of NGC 1222 (Mkn 603)

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    The infrared spectra of starburst galaxies are dominated by the low-excitation lines of [NeII] and [SIII], and the stellar populations deduced from these spectra appear to lack stars larger than about 35 Msun. The only exceptions to this result until now were low metallicity dwarf galaxies. We report our analysis of the mid-infrared spectra obtained with IRS on Spitzer of the starburst galaxy NGC 1222 (Mkn 603). NGC 1222 is a large spheroidal galaxy with a starburst nucleus that is a compact radio and infrared source, and its infrared emission is dominated by the [NeIII] line. This is the first starburst of solar or near-solar metallicity, known to us, which is dominated by the high-excitation lines and which is a likely host of high mass stars. We model the emission with several different assumptions as to the spatial distibution of the high- and low-excitation lines and find that the upper mass cutoff in this galaxy is 40-100 Msun.Comment: accepted, Astronomical Journal. 29 pp, 4 figures. In replacement version an acknowledgment to NRAO is adde

    Droplet size and morphology characterization for diesel sprays under atmospheric operating conditions

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    The shape of microscopic fuel droplets may differ from the perfect sphere, affecting their external surface area and thus the heat transfer with the surrounding gas. Hence there is a need for the characterization of droplet shapes, and the estimation of external surface area, in order to enable the development of physically accurate mathematical models for the heating and evaporation of diesel fuel sprays. We present ongoing work to automat-ically identify and reconstruct the morphology of fuel droplets, primarily focusing in this study on irregularly-shaped, partially-deformed and oscillating droplets under atmospheric conditions. We used direct imaging tech-niques based on long-working distance microscopy and ultra-high-speed video to conduct a detailed temporal investigation of droplet morphology. We applied purpose-built algorithms to extract droplet size, velocity, vol-ume and external surface area from the microscopic ultra-high-speed video frames. High resolution images of oscillating droplets and a formation of a droplet form ligament, sphericity factors, volume as well as external surface area are presented for 500 bar injection pressure in the near nozzle region (up to 0.7 mm from nozzle exit) under atmospheric conditions. We observed a range of different liquid structures, including perfectly spher-ical, non-spherical droplets and stretched ligaments. We found that large droplets and ligaments exceeding the size of the nozzle hole could be found at the end of injection. In order to estimate droplet volume and external surface area from two-dimensional droplet information, a discrete revolution of the droplet silhouette about its major centroidal axis was used. Special attention was paid to the estimation of actual errors in the prediction of volume and surface characteristics from a droplet silhouette. In addition to the estimation of droplet volume and external surface area, the actual shape reconstruction in 3D coordinates from a droplet silhouette was performed in order to enable future numerical modelling studies of real droplets

    Monitoring changes in power, speed, agility and endurance in elite cricketers during the off-season

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    The purpose of this study was to monitor changes in power, speed, agility and endurance in elite cricketers during the 20-week off-season period. Fourteen elite male cricketers (age 26.2 ± 5.3years; height 180.8 ± 8.5cm; mass 83.5 ± 6.7kg) conducted a physical testing battery in week 1 and week 18 of the off-season period. The testing included a yoyo intermittent recovery test (yoyo IRT), bilateral and unilateral countermovement jumps (CMJ), squat jump (SJ), broad jump (BJ), drop jump (to calculate reactive strength index – [RSI]), pro agility and 5, 10, 20m sprint tests. Results showed significant improvements (p < 0.05) in all fitness tests except for the pro-agility test (p = 0.076), with effect sizes ranging from 0.26-2.8 across the test battery. The results of this study show the off-season in cricket allows adequate time for significant improvements of physical qualities needed for the demanding in-season schedule of the sport and provide normative values for an elite cricket population

    A semantic method

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    We may wonder about the status of logical accounts of the meaning of language. When does a particular proposal count as a theory? How do we judge a theory to be correct? What criteria can we use to decide whether one theory is ?better? than another? Implicitly, many accounts attribute a foundational status to set theory, and set-theoretic characterisations of possible worlds in par-ticular. The goal of a semantic theory is then to find a translation of the phenomena of interest into a set-theoretic model. Such theories may be deemed to have ?explanatory? or ?predictive? power if a map-ping can found into expressions of set-theory that have the appropri-ate behaviour by virtue of the rules of set-theory. This can be con-trasted with an approach in which we can help ourselves to ?new? primitives and ontological categories, and devise logical rules and axioms that capture the appropriate inferential behaviour. This alter-native approach can be criticised as being mere ?descriptivism?, lack-ing predictive or explanatory power. Here we will seek to defend the ?descriptivist? approach. Any formal account must assume some normative interpretation, but there is a sense in which descriptivist theories can provide a more honest cha-racterisation. In contrast, the set-theoretic approach tends to conflate distinct ontological notions. Mapping a pattern of semantic behaviour into some pre-existing set-theoretic behaviour may lead to certain aspects of that behaviour being overlooked, or ignored. Arguments about the explanatory and predictive power of set-theoretic interpre-tations can also be questioned. We aim to provide alternative notions for evaluating the quality of a formalisation, and the role of formal theory. Ultimately, claims about the inadequacies of ?descriptivist? accounts compared to set-theoretic reductions must rely on criteria and assumptions that lie outside the domain of formal semantics as such
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