1,022 research outputs found

    Degradation of road tested automotive connectors

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    The automotive environment is particularly demanding on connector performance, and is characterized by large temperature changes, high humidity and corrosive atmospheres. This paper presents an initial study of connector performance in terms of temperature profiles taken from road vehicles. The temperature profiles are then simulated using empirical relationships to allow prediction of connector performance. Wire harnesses have been investigated to seek evidence of the connector degradation predicted from the temperature data. Initial indications are that the wire harness shows the type of fretting behavior associated with the temperature changes. Evidence of fretting corrosion was found at the contact interface on tin plated terminals from sealed and unsealed connectors

    Comparison of Simulator Wear Measured by Gravimetric vs Optical Surface Methods for Two Million Cycles

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    Understanding wear mechanisms are key for better implants Critical to the success of the simulation Small amount of metal wear can have catastrophic effects in the patient such as heavy metal poisoning or deterioration of the bone/implant interface leading to implant failure Difficult to measure in heavy hard-on-hard implants (metal-on-metal or ceramic-on-ceramic) May have only fractions of a milligram of wear on a 200 g component At the limit of detection of even high-end balances when the component is 200 g and the change in weight is on the order of 0.000 1 grams Here we compare the standard gravimetric wear estimate with A non-contact 3D optical profiling method at each weighing stop A coordinate measuring machine (CMM) at the beginning and end of the ru

    Memory effects in electrochemically gated metallic point contacts

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    L’ADAPTATION POSITIVE DES FAMILLES LATINOS AVEC UN ENFANT AYANT UNE DÉFICIENCE INTELLECTUELLE: UNE PREMIÈRE VUE DE LA THÉORIE DE L’ADAPTATION POSITIVE

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    Historically, research on disability and family dynamics drew from Psychology and Medicine. Consequently, eugenics models, grief theory, and other largely decontextualized frameworks of stress and coping were used to explain families of children with disabilities. This is a report of an initial test of a set of ideas the Singer research team has combined in order to explore the cognitive and problem-solving approaches of families of children with disabilities. Our purpose is to propose a contextualized theory for explaining how cultural diversity has an impact on positive adaptation to a child’s disability. This theory addresses the following: 1) attachment; 2) internal and external cultural resistance to stigmas about disability; and 3) perceived informal (family/friends) and formal (professionals) sources of support for positive views about disability and parenting. Sampling Latino families demonstrated how cultural contexts demonstrate a different flavour from majority culture interpretations of these cognitive terms of our proposed theory. Transcripts of the interviews were coded using grounded theory analysis, specifically, the constant comparative method. We discuss the goodness of fit for themes emerging from the coding process with the proposed theory terms. Results confirm attachment, social supports, and cultural resistance as terms for future development of this proposed theory. Keywords: Disability and parenting, positive adaptation, Latinos and disability, culture and disabilityÀ travers l’histoire, la recherche sur les handicapés et les relations intrafamiliales utilisait comme sources la psychologie et la médicine. Par conséquent, les modèles de l’eugénisme, les théories sur le deuil, et d’autres cadres analytiques sur le stress et les stratégies d’adaptation, plutôt décontextualisés, étaient utilisés afin d’expliquer aux autres comment fonctionnaient les familles avec un enfant handicapé. Ceci est un reportage sur un test initial d’un ensemble d’idées qu’a combiné l’équipe de recherche Singer afin d’aborder les approches cognitives et méthodes actives des familles des enfants handicapés. Nous proposons une théorie contextualisée afin d’expliquer comment la diversité culturelle aurait un effet sur l’adaptation positive de la famille face à l’handicap de leur enfant. Cette théorie aborde les idées suivantes : 1) l’attachement; 2) les résistances culturelles internes et externes aux stigmates sur l’handicap; et 3) les sources d’information sur l’handicap et le parentage liées à l’adaptation positive perçues comme informelles (famille/amis) et formelles (les professionnels). En utilisant un échantillon de familles Latinos, nous démontrons comment les contextes culturels démontrent des interprétations différentes des termes cognitifs de notre théorie, et non l’interprétation de la culture majoritaire. Les transcriptions des interviews étaient codées selon la théorie ancrée, plus spécifiquement la méthode de la comparaison constante. Nous discutons la concordance des thèmes venus via le processus d’encodage avec les termes clés de la nouvelle théorie proposée. Les résultats de cette recherche confirment que l’attachement, le soutien social, et la résistance culturelle seront des termes clés dans le développement de cette théorie proposée. Mots clés : Handicap et parentage, Adaptation positive, Latinos et handicap, culture et handica

    Vector-pseudoscalar two-meson distribution amplitudes in three-body BB meson decays

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    We study three-body nonleptonic decays BVVPB\to VVP by introducing two-meson distribution amplitudes for the vector-pseudoscalar pair, such that the analysis is simplified into the one for two-body decays. The twist-2 and twist-3 ϕK\phi K two-meson distribution amplitudes, associated with longitudinally and transversely polarized ϕ\phi mesons, are constrained by the experimental data of the τϕKν\tau\to\phi K\nu and BϕKγB\to\phi K\gamma branching ratios. We then predict the BϕKγB\to\phi K\gamma and BϕϕKB\to\phi\phi K decay spectra in the ϕK\phi K invariant mass. Since the resonant contribution in the ϕK\phi K channel is negligible, the above decay spectra provide a clean test for the application of two-meson distribution amplitudes to three-body BB meson decays.Comment: 9 pages, 1 figure, Revtex4, version to appear in PR

    Determining North Atlantic meridional transport variability from pressure on the western boundary: a model investigation.

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    In this paper we investigate the possibility of determining North Atlantic meridional transport variability using pressure on the western boundary, focusing on the 42degN latitude of the Halifax WAVE array. We start by reviewing the theoretical foundations of this approach. Next we present results from a model analysis, both statistical and dynamic, that demonstrate the feasibility of the approach. We consider how well we can quantify the meridional transport variability at 42degN given complete knowledge of bottom pressure across the basin, and to what degree this quantification is degraded by first ignoring the effect of intervening topography, and then by using only bottom pressure on the western boundary. We find that for periods of greater than one year we can recover more than 90% of the variability of the main overturning cell at 42degN using only the western boundary pressure, provided we remove the depth-average boundary pressure signal. This signal arises from a basin mode of bottom pressure variability, which has power at all timescales, but that does not in truth have a meridional transport signal associated with it, and from the geostrophic depth-independent compensation of the Ekman transport. An additional benefit of the removal of the depth-average pressure is that this high-frequency Ekman signal, which is essentially noise as far as monitoring the MOC for climatically important changes is concerned, is clearly separated from other modes
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