55,717 research outputs found

    Assessing Aquatic Insect Flight Behavior with Sticky Traps

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    A suspended sticky trap was designed to analyze flight behavior of aquatic insects, including both direction and vertical distribution of flight. Specifications of trap construction are detailed. Possible applications were explored and preliminary results from the study of a small Indiana stream demonstrated primary upstream migration of females, and indicated vertical partitioning of flight activity at the species level

    US GAAP Conversion To IFRS: A Case Study Of The Cash Flow Statement

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    International Reporting Standards (IFRS) has become the required framework for most of the world financial market economies as of January 1, 2011. This includes, in a non-comprehensive listing, the many European Union countries - Canada, Australia and New Zealand. In the United States, US Generally Accepted Accounting Principles (GAAP) is still required. However, plans are presently in place by the SEC to abandon US GAAP and to adhere to IFRS requirements by as early as for the period ending December 31, 2014. As such, it is important to introduce IFRS accounting rules in the college curriculum and make it a major component of accounting classes. This case study takes a US GAAP Prepared Cash Flow Statement and, based on the facts of the case, requires students to prepare an IFRS-based Cash Flow Statement. The need to understand both US GAAP and IFRS rules is required to adequately address this case study, which is most suitable for an Intermediary Accounting, Accounting Theory and a Financial Statement Analysis class, as well as an Investment Finance course, at the graduate level

    On empirical models of the upper atmosphere in the polar regions

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    Modified expression for exospheric temperature in Jacchia static diffusion models of upper atmosphere in polar region

    A new readily processable polyimide

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    As part of an effort to develop tough solvent resistance thermoplastics for potential use as structural resins on aerospace vehicles, a new processable polyimide was evaluated. The synthesis involved the reaction of a new diamine, 1,3-bis 2-(3-aminophenoxy)ethyl ether, with 3,3',4,4'-benzophenonetetracarboxylic dianhydride to form the polyamic acid and subsequent conversion of it to the polyimide. Various physical properties such as thermal stability, solvent resistance, glass transition temperature, crystalline melt temperature, melt viscosity and mechanical properties such as fracture toughness, adhesive, film and composite properties are reported. Of particular interest is the extremely high titanium to titanium tensile shear strength obtained for this polyimide

    Discrete Group Actions on Spacetimes: Causality Conditions and the Causal Boundary

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    Suppose a spacetime MM is a quotient of a spacetime VV by a discrete group of isometries. It is shown how causality conditions in the two spacetimes are related, and how can one learn about the future causal boundary on MM by studying structures in VV. The relations between the two are particularly simple (the boundary of the quotient is the quotient of the boundary) if both VV and MM have spacelike future boundaries and if it is known that the quotient of the future completion of VV is past-distinguishing. (That last assumption is automatic in the case of MM being multi-warped.)Comment: 32 page

    Structural parameters for globular clusters in M31 and generalizations for the fundamental plane

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    The structures of globular clusters (GCs) reflect their dynamical states and past histories. High-resolution imaging allows the exploration of morphologies of clusters in other galaxies. Surface brightness profiles from new Hubble Space Telescope observations of 34 globular clusters in M31 are presented, together with fits of several different structural models to each cluster. M31 clusters appear to be adequately fit by standard King models, and do not obviously require alternate descriptions with relatively stronger halos, such as are needed to fit many GCs in other nearby galaxies. The derived structural parameters are combined with corrected versions of those measured in an earlier survey to construct a comprehensive catalog of structural and dynamical parameters for M31 GCs with a sample size similar to that for the Milky Way. Clusters in M31, the Milky Way, Magellanic Clouds, Fornax dwarf spheroidal and NGC 5128 define a very tight fundamental plane with identical slopes. The combined evidence for these widely different galaxies strongly reinforces the view that old globular clusters have near-universal structural properties regardless of host environment.Comment: AJ in press; 59 pages including 16 figure

    Design and experimental evaluation of a swept supercritical Laminar Flow Control (LFC) airfoil

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    A large chord swept supercritical laminar flow control (LFC) airfoil was designed, constructed, and tested in the NASA Langley 8-ft Transonic Pressure Tunnel (TPT). The LFC airfoil experiment was established to provide basic information concerning the design and compatibility of high-performance supercritical airfoils with suction boundary layer control achieved through discrete fine slots or porous surface concepts. It was aimed at validating prediction techniques and establishing a technology base for future transport designs and drag reduction. Good agreement was obtained between measured and theoretically designed shockless pressure distributions. Suction laminarization was maintained over an extensive supercritical zone up to high Reynolds numbers before transition gradually moved forward. Full-chord laminar flow was maintained on the upper and lower surfaces at M sub infinity = 0.82 up to R sub c is less than or equal to 12 x 10 to the 6th power. When accounting for both the suction and wake drag, the total drag could be reducted by at least one-half of that for an equivalent turbulent airfoil. Specific objectives for the LFC experiment are given

    Opacity of electromagnetically induced transparency for quantum fluctuations

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    We analyze the propagation of a pair of quantized fields inside a medium of three-level atoms in Λ\Lambda configuration. We calculate the stationary quadrature noise spectrum of the field after propagating through the medium, in the case where the probe field is in a squeezed state and the atoms show electromagnetically induced transparency (EIT). We find an oscillatory transfer of the initial quantum properties between the probe and pump fields which is most strongly pronounced when both fields have comparable Rabi frequencies. This implies that the quantum state measured after propagation can be completely different from the initial state, even though the mean values of the field are unaltered

    A new squirrel of the Sciurus hoffmanni group from Costa Rica

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    http://deepblue.lib.umich.edu/bitstream/2027.42/56666/1/OP227.pd
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