2,456 research outputs found

    Brazing process provides high-strength bond between aluminum and stainless steel

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    Brazing process uses vapor-deposited titanium and an aluminum-zirconium-silicon alloy to prevent formation of brittle intermetallic compounds in stainless steel and aluminum bonding. Joints formed by this process maintain their high strength, corrosion resistance, and hermetic sealing properties

    Method of joining aluminum to stainless steel Patent

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    Joining aluminum to stainless steel by bonding aluminum coatings onto titanium coated stainless steel and brazing aluminum to aluminum/titanium coated stee

    Associated Insects Reared from Galls of Saperda Inornata (Coleoptera: Cerambycidae) on Trembling Aspen in Michigan

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    The poplar gall Saperda, Saperda inornata Say, is a common pest of trembling aspen, Populus tremuloides Michx, in Michigan forests. Through its egg-laying activities and larval feeding, this insect causes wood defects and tree mortality (Graham et al., 1963). While studying natural populations of this insect (Grimble and Knight, 1970), we collected many galls and found through rearing and dissection that they harbor a large and varied insect fauna

    Resolving the Troubled IT-Business Relationship from a Cultural Perspective

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    This research investigates the effects of the culture of the information technology (IT) group on the relationship between business and IT professionals within two Australian organisations, one a public sector organisation, and the other a private company. The IT groups in these two organisations had many similar themes of culture. Both organisations reported a troubled IT-business relationship. This research investigates the effects of the themes of IT culture that surfaced in each organisation on six essential ingredients of an effective IT-business relationship, providing some suggestions for management to consider to improve their troubled IT-business business relationship

    Evaluation of Toxicity, Bioavailability and Speciation of Lead, Zinc and Cadmium in Mine/Mill Wastewaters

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    The toxicity of common compounds of lead, cadmium and zinc was evaluated in waters similar to that found in the world\u27s largest lead producing area in Missouri. Static, acute toxicity tests were performed using fathead minnows (Pimephales promelas) and water fleas (Daphnia magna) respectively. Test organisms were subjected to varying amounts of sulfide, carbonate, chloride and sulfate salts of lead, zinc and cadmium mixed in hard, alkaline waters typical to this region. Median lethal concentrations were calculated using nominal versus measured metal concentrations. Measured metal concentrations included four different metal fractionation (extraction/filtration) techniques at different pH levels which included dissolved , available , easily dissolved and total metals. Most consistent correlations between mortality and metal concentrations were found with the Total or Nominal values. The Easily Dissolved metals which corresponded to acid soluble criteria did not effectively represent toxicity and bioavailability of metals. A metal speciation model, MINTEQA2, was used to predict the concentrations of the dissolved metal species at the pH levels commonly seen in the toxicity test vessels. MINTEQ model results suggested that analysis of metals in aqueous environment is better understood when examining speciation characteristics and would likewise be a better mechanism to develop site-specific water quality criteria for metals

    Towards More Accurate Molecular Dynamics Calculation of Thermal Conductivity. Case Study: GaN Bulk Crystals

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    Significant differences exist among literature for thermal conductivity of various systems computed using molecular dynamics simulation. In some cases, unphysical results, for example, negative thermal conductivity, have been found. Using GaN as an example case and the direct non-equilibrium method, extensive molecular dynamics simulations and Monte Carlo analysis of the results have been carried out to quantify the uncertainty level of the molecular dynamics methods and to identify the conditions that can yield sufficiently accurate calculations of thermal conductivity. We found that the errors of the calculations are mainly due to the statistical thermal fluctuations. Extrapolating results to the limit of an infinite-size system tend to magnify the errors and occasionally lead to unphysical results. The error in bulk estimates can be reduced by performing longer time averages using properly selected systems over a range of sample lengths. If the errors in the conductivity estimates associated with each of the sample lengths are kept below a certain threshold, the likelihood of obtaining unphysical bulk values becomes insignificant. Using a Monte-Carlo approach developed here, we have determined the probability distributions for the bulk thermal conductivities obtained using the direct method. We also have observed a nonlinear effect that can become a source of significant errors. For the extremely accurate results presented here, we predict a [0001] GaN thermal conductivity of 185 W/Kâ‹…m\rm{W/K \cdot m} at 300 K, 102 W/Kâ‹…m\rm{W/K \cdot m} at 500 K, and 74 W/Kâ‹…m\rm{W/K \cdot m} at 800 K. Using the insights obtained in the work, we have achieved a corresponding error level (standard deviation) for the bulk (infinite sample length) GaN thermal conductivity of less than 10 W/Kâ‹…m\rm{W/K \cdot m}, 5 W/Kâ‹…m\rm{W/K \cdot m}, and 15 W/Kâ‹…m\rm{W/K \cdot m} at 300 K, 500 K, and 800 K respectively

    Ralph B. Stine and Margaret E. Stine v. Henry Girola and Diane Girola and State Underwriters, Inc. : Petition for Rehearing

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    In this paper we present a Remote Control Unit (RCU) that can be attached to any location on a rifle, binoculars, etc., and be operated by a single finger of a soldier without removing his hand from the device. Even for a gloved hand a haptic feedback from the RCU will be realized. A RCU prototype, equipped with a single button, is used as a remote Push-to-Talk (PTT) device for the radio being carried by the soldier. The RCU is powered by the radio waves emitted by this radio. The RCU - being attached to the device - works with a receive unit (RXU) that is attached to and operates the radio. The RCU consists of a RF harvester, energy storage device, a button and a transmitter. Laboratory prototypes are demonstrated

    Spatially explicit stock assessment uncovers sequential depletion of northern shrimp stock components in the North Sea

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    Space is a critical component of fisheries management. Despite this, very few of the world's fish and shellfish stocks are currently assessed using methods that are spatially structured. In the Northeast Atlantic, northern shrimp in the North Sea and Skagerrak, is currently assessed using a spatially structured assessment model. This metapopulation model includes two spatial units (the Norwegian Deep and the Skagerrak), however, in the recent past, the fishery on northern shrimp in the North Sea also occurred in a third neighbouring fishing area, the Fladen Ground. Here, we have reconstructed the dynamics of northern shrimp in the Fladen Ground using historic landings, a standardized commercial index of abundance and fragmented survey data and integrated this third spatial unit into the assessment model of the stock. In doing so, we find evidence of sequential spatial depletion, whereby high rates of fishing mortality have successively eroded stock components in a west to east pattern of overexploitation and produced cryptic collapses. This finding is the first documented case of sequential spatial depletion in the Northeast Atlantic, a phenomenon that could be common and largely overlooked by stock assessment methods that are inherently non-spatial
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