2,755 research outputs found

    Fuse-holder concept expedites electronic component changes

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    Mounting circuit components in fuse holders facilitates component changing and extends component life with an estimated fifty percent saving of breadboard test time. Glass sleeves of the fuse holders allow easy component identification

    Coded photographic proof paper could serve as convenient densitometer

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    Standard print-out proofing paper, preprinted with an identifying code, serves as convenient densitometer. Exposure to light darkens the paper and gives a measure of the density of the resultant photographic image or the total amount of exposure sustained by the paper

    Study of adhesion and cohesion in vacuum Final report

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    Vacuum metal-metal bonding tests to determine conditions of accidental adhesion of spacecraft structural material

    Study of adhesion and cohesion in vacuum summary report 1 jul. 1963 - 30 jun. 1964

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    Adhesion and cohesion of metal couples in vacuum chambe

    Preliminary Engineering Geology Report of Dam Sites on the East Fork of the Muscatatuck River in Scott, Jennings, and Jefferson Counties, Indiana

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    Preliminary engineering geology investigations have been made of four proposed dam sites and their reservoir areas in the valley of the East Fork of the Muscatatuck River and its tributaries, Big Camp and Big Graham Creeks, in northern Scott County, southern Jennings County, and western Jefferson County, Ind. In this report the geologic column of the area has been divided, according to engineering characteristics, into five units. The bedrock consists of (in ascending order) unit 1, the Osgood Formation and the Laurel Limestone of Silurian age; unit 2, the Waldron Shale and the Louisville Limestone of Silurian age and the Geneva Dolomite and the Jeffersonville Limestone of Devonian age; unit 3~ the North Vernon Limestone of Devonian age; and unit 4~ the Devonian portion of the New Albany Shale. These rocks are overlain at most places by unit 5, the unconsolidated materials that range in character from red residual limestone soils to glacial till. The bedrock formations stratigraphically below the North Vernon Limestone (units 1 and 2) are essentially sound rock and offer few problems to dam and reservoir construction except the possibility of a small amount of leakage. The Jeffersonville Limestone (the top formation of unit 2) includes a gray limestone bed that contains a few solution channels, but otherwise it is sound rock. Most of the solution channels and sinkholes in the area have been formed in the North Vernon Limestone (unit 3), and serious leakage from the reservoir probably would occur through this formation if it were not extensively grouted. The New Albany Shale (unit 4) weathers quickly where it is exposed at the surface, and spillways on the New Albany Shale must be designed to prevent the rapid erosion of the shale under the attack of running water. The red residual limestone soils (of unit 5) have high liquid limits, but these materials would make a satisfactory impermeable clay core of an earth dam. The other unconsolidated materials (glacial till, outwash silt and sand, and loess) overlying the bedrock are thin but sufficient in quantity to provide fill material for earth dams. Quarries could be opened in the limestone formations at any of the dam sites to supply concrete aggregate and fill material

    Linked disturbance interactions in South-Central Alaska: implications for ecosystems and people

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    Thesis (M.S.) University of Alaska Fairbanks, 2013Communities and ecosystems in the Alaskan boreal forest are undergoing substantial change. People contribute to this change. They are also impacted by the consequences. For example, wildfire and spruce bark beetle (Dendroctonus rufipennis) outbreaks have increased in frequency and severity due to warming trends, affecting the ecosystem and services important to people. I conducted a study to explore the social and ecological implications of changing natural disturbances. I evaluated how the occurrence of spruce bark beetle outbreak has altered the probability of wildfire between 2001 and 2009 on the Kenai Peninsula, Alaska. Modeling the effects of bark beetle outbreak on the probability of large wildfire (> 500 ha) and small wildfires ( 3.3 ha and the bark-beetle outbreak increased property values. Wildfires <3.3 ha decreased property values.Chapter 1. General introduction -- Chapter 2. Linked disturbance interactions in South-Central Alaska: the effects of a spruce bark beetle (Dendroctonus rufipennis) outbreak on a changing boreal wildfire regime -- Chapter 3. The effects of a spruce bark beetle outbreak and wildfires on property values in the wildland-urban interface of South-central, Alaska, USA -- 4. General conclusions

    Changes In The Bacterial Flora Of Sewage During Storage

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    Verification in Staged Tile Self-Assembly

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    We prove the unique assembly and unique shape verification problems, benchmark measures of self-assembly model power, are coNPNP\mathrm{coNP}^{\mathrm{NP}}-hard and contained in PSPACE\mathrm{PSPACE} (and in Π2sP\mathrm{\Pi}^\mathrm{P}_{2s} for staged systems with ss stages). En route, we prove that unique shape verification problem in the 2HAM is coNPNP\mathrm{coNP}^{\mathrm{NP}}-complete.Comment: An abstract version will appear in the proceedings of UCNC 201

    Surface Flaw Detection with Ferromagnetic Resonance Probes

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    Ferromagnetic probes resonating at microwave frequencies have previously been shown to function as sensitive detectors of surface breaking flaws in metals. A swept frequency mode of operation was used, with the resonance line of the probe displayed on an oscilloscope and the presence of a flaw indicated by a shift of the resonance line. This type of presentation lacks good discrimination between lift-off and and flaw signals and also reduces the probe scanning speed because the entire resonance line must be swept at each measurement point on the test specimen. Our new system operates under cw conditions, with a network analyser type of display giving the probe input impedance in polar coordinates. This provides liftoff discrimination and also enhances sensitivity. Experimental curves and their theoretical interpretations will be presented, and a portable prototype instrument will be described
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