15,495 research outputs found

    Endless tape transport mechanism Patent

    Get PDF
    Endless loop tape transport mechanism for driving and tensioning recording medium in magnetic tape recorde

    Making serine integrases work for us

    Get PDF
    DNA site-specific recombinases are enzymes (often associated with mobile DNA elements) that catalyse breaking and rejoining of DNA strands at specific points, thereby bringing about precise genetic rearrangements. Serine integrases are a group of recombinases derived from bacteriophages. Their unusual properties, including directionality of recombination and simple site requirements, are leading to their development as efficient, versatile tools for applications in experimental biology, biotechnology, synthetic biology and gene therapy. This article summarizes our current knowledge of serine integrase structure and mechanism, then outlines key factors that affect the performance of these phage recombination systems. Recently published studies, that have expanded the repertoire of available systems and reveal system-specific characteristics, will help us to choose the best integrases for envisaged applications

    Micro-pound extended range thrust stand Patent

    Get PDF
    Micro-pound extended range thrust stand for small rocket engine

    Age- and length-at-maturity of female arrowtooth flounder (Atheresthes stomias) in the Gulf of Alaska

    Get PDF
    Arrowtooth flounder (Atheresthes stomias) has had the highest abundance of any groundfish species in the Gulf of Alaska since the 1970s (Matarese et al., 2003; Turnock et al., 2005; Blood et al., 2007); however, commercial catches have been restricted because Pacific halibut (Hippoglossus stenolepis) are caught as bycatch in the fishery. Arrowtooth flounder plays a key role in the ecosystem because it is a dominant organism within the food web, both as an apex predator of fish and invertebrates, as well as an important prey for walleye pollock (Theragra chalcogramma; Aydin et al., 2002). Walleye pollock is the dominant groundfish in the Bering Sea, a principal groundfish in the Gulf of Alaska, and the primary prey for marine mammals. The distribution of arrowtooth flounder extends from Cape Navarin and the eastern Sea of Okhotsk in Russia, across the Bering Sea, Aleutian Islands, Gulf of Alaska, and south to the coast of central California (Shuntov, 1964; Britt and Martin, 2001; Chetvergov, 2001; Weinberg et al., 2002; Zenger, 2004). Because of the importance of arrowtooth flounder in the marine ecosystem of A laska, a maturity study of this species was undertaken to determine age-at-maturity, which is essential for age-based stock management models. Before these results, management has had to rely upon a length-at-maturity-based estimate (Zimmermann, 1997) to manage stocks in the Gulf of Alaska (GOA), Bering Sea, and Aleutian Islands. The central GOA was selected as the location for this maturity study Age- and length-at-maturity of female arrowtooth flounder (Atheresthes stomias) in the Gulf of Alaska because it contains approximately 70% of the total Gulf of Alaska arrowtooth flounder biomass (1.9×106 t, age 3 and older)— the highest percentage in the world (Shuntov, 1964; Britt and Martin, 2001; Weinberg et al., 2002; Wilderbuer and Nichol, 2006)

    Endless tape cartridge Patent

    Get PDF
    Tape cartridge with high capacity storage of endless-loop magnetic tap

    A mirror transport mechanism for use at cryogenic temperatures

    Get PDF
    The Mirror Transport Mechanism (MTM), which supports a pair of dihedral mirrors and moves them in a very smooth and uniform scanning motion normal to a beamsplitter is described. Each scan is followed by a quick flyback and repeat. Material selection, design, and testing of all major components of the MTM are discussed. Flex pivot failures during vibration testing, excessive dihedral platform sag under one g operation, electronic and fiber optic characteristics, and tolerancing considerations are covered. Development of the mechanism has reached the final phase of thermal and vibration qualification. Environmental testing of the complete FIRAS experiment is just beginning

    Is there an accruals or a cash flow anomaly in UK stock returns?

    Get PDF
    In this paper, we apply a modified version of the Mishkin (1983) test to companies in the UK stock market in order to investigate the presence of accruals and cash flow effects on UK firms’ annual returns. First, we find that accruals decile rankings have U-shaped, or inverted U-shaped, or no relationships with most of the risk variables. Accruals decile rankings have, however, a negative relationship with the ratio of research and development to market value which is known to have a positive relationship with returns. Second, regarding the relationship between risk controls and returns, we find evidence associated with an RD effect and some evidence in favour of earnings-price and past return effects. We find little evidence of firm size, book to-market, and firm leverage effects, once the other variables are controlled for. Third, for the period 1990-2007, we report little evidence of general accruals mispricing in the UK in which accruals have a negative relationship with future returns, once risk has been accounted for. Additionally, after treatment of extreme observations, evidence of cash flow mispricing is found for the UK stock market. An alternative interpretation of our results is that there is no separate accruals effect, at least in the way predicted by the conventional mispricing stories, once other effects are taken into account, but there is a separate cash flow effect.Accruals anomaly, accrual based accounting, cash flows, financial statement analysis

    Cantilever micro-rheometer for the dcharacterization of sugar solutions

    Get PDF
    The volume required for the rheological characterization of fluids can be minimized by using micromechanical cantilevers as viscosity sensors. Here, a simple measurement tool for the characterization of sugar solutions is proposed. The sensor consists of a micromechanical cantilever as used in an atomic force microscopy which is integrated into a closed fluid handling system. Fluid properties are derived from an analysis of the power spectral density of the fluctuations of the cantilever deflection signal. The data acquisition system is operated with standard consumer computer components, which limits the costs for the hardware. Measurements with different sugar solutions indicate that the sensor system provides reliable viscosity values for sugar concentrations as they occur in biological systems. The viscosities of the sugar solutions could be evaluated with an error smaller than 5%

    Doing business in space: How to get there from here

    Get PDF
    A step by step process is described through which an existing enterprise or an entrepreneurial venture can initiate and carry out a new space venture. Throughout this process the business and technical aspects must be advanced in parallel with each other. Each depends on the other for its continued success, and companies may be unable to complete the venture if one or the other is neglected. The existing NASA programs and the experience of early trailblazers provide sufficient examples and opportunities for other firms to undertake new ventures with confidence. With the introduction of NASA's Commercial Space Policy, both the opportunities and the ease with which ventures can be carried out should increase significantly
    • …
    corecore