25,836 research outputs found

    Collimated beam manifold with the number of output beams variable at a given output angle

    Get PDF
    An optical manifold is described which transforms a collimated beam, such as a laser beam, into a plurality of parallel beams having uniform intensity or having a desired intensity ratio. The manifold comprises an optical substrate coated on its rear surface with a fully reflective layer and on its front surface with a partially reflecting layer having a reflectivity gradient. An input collimated beam entering the rear surface and impinging on the front surface is reflected, multiply between the front and rear surfaces producing a plurality of parallel beams that emerge from the front surface. The intensities of the emerging beams have a relationship that depends on the reflectivity of the front surface at the points where the beams emerge. By properly selecting the reflectivity gradient, the emerging beams have uniform intensity or a desired intensity ratio

    Emerging trends in government venture capital policies in smaller peripheral economies: lessons from Finland, New Zealand, and Estonia

    Get PDF
    Emerging trends from the developing venture capital industries of three smaller peripheral economies (Finland, New Zealand, and Estonia), demonstrate that government policy can overcome scale and distance barriers to assist in establishing venture capital to support innovative potential high growth ventures. Eight common policy themes for successful venture capital development are: new venture stimulation; dedicated finance policy institutions; stable, internationally harmonized tax and regulations; business angel development; inward investment; international venture capital fund development; smooth pipeline of investment; effective investment exit market. Venture capital policy development themes are interconnected, requiring a holistic ecosystem approach. A blueprint for successful small peripheral economy venture capital development requires an initial phase of new venture demand stimulation and ensuing simultaneity of policies to engineer venture capital development

    The role of government co-investment funds in the supply of entrepreneurial finance: An assessment of the early operation of the UK Angel Co-investment Fund

    Get PDF
    Co-investment funds – which invest alongside private investors, especially business angels – thereby leveraging their networks and experience and minimizing public sector transaction costs – are a recent approach by governments in various countries to address the early stage entrepreneurial funding gap which is perceived as a barrier to the ability of firms to scale-up. However, little literature exists on their operation, impact and effectiveness. This paper assesses the early operation of the UK’s Angel Co-investment Fund, established in 2011. Interview evidence from angels and business managers suggests that the Angel Co-investment Fund is improving the availability of finance by enabling firms to raise funding rounds of between £500,000 and £2 m, hence addressing some aspects of the broken finance escalator model. However, our evidence suggests that it is not yet impacting the supply side, either in terms of stimulating the formation of new angel groups or enhancing learning amongst less experienced angels. Some aspects of the operation of the investment process have attracted criticism from angels and entrepreneurs which need to be addressed. Nevertheless, there is sufficient evidence for positive impact to justify the scheme’s expansion

    Establishing a new UK finance escalator for innovative SMEs: the roles of the Enterprise Capital Funds and Angel Co-investment Fund

    Get PDF
    This paper examines UK public policy addressing the seed and early stage equity finance gap since the Global Financial Crisis (GFC). Drawing on lessons learned from recent studies of UK and international government equity schemes, two contemporary models of government backed equity finance are examined. The focus is on the Enterprise Capital Funds (ECFs) and the Angel Co-investment Fund (ACF), the UK government’s main schemes operating in the sub-£2m equity finance gap to address the capital requirements for developing the UK’s young, potential high growth businesses. The paper highlights the shortcomings of traditional interim fund performance analysis and presents current demand and supply side evidence that establishes that these schemes are making attributable impacts on their portfolio businesses and the wider UK economy. It also demonstrates that they are playing important roles in the establishment of a new post GFC UK finance escalator. However, whilst these schemes were found to be currently complementary and effective, their future roles within the UK’s evolving post GFC seed and early stage equity markets are also considered. Key Words: Government Equity Schemes, Venture Capital, Potential High Growth SME

    Measurement of long-range steric repulsions between microspheres due to an adsorbed polymer

    Get PDF
    We have measured the interparticle potential between pairs of micron-sized silica spheres induced by adsorbed polyethylene oxide polymer using a line-scanned optical tweezer. We found this long-range steric repulsion to be exponential over the range of energies (0.1kBT–5kBT) and polymer molecular weights (452 000–1 580 000) studied, and that the potential scaled with the polymer’s radius of gyration RG. The potential’s exponential decay length was about 0.6RG and its range was about 4RG, although both parameters varied significantly from one pair of spheres to another. The potential’s exponential prefactor was greater than mean-field predictions

    Ion-tracer anemometer

    Get PDF
    Gas velocity measuring instrument measures transport time of ion-trace traveling fixed distance between ionization probe and detector probe. Electric field superimposes drift velocity onto flow velocity so travel times can be reduced to minimize ion diffusion effects

    Corn varieties in Mississippi

    Get PDF

    Experimental studies of hypersonic boundary-layer transition and effects of wind tunnel disturbances

    Get PDF
    Boundary layer transition data on cones and free stream disturbance levels were measured in a hypersonic wind tunnel and Mach 8 variable density hypersonic tunnel. Transition data were obtained by using different conical models and techniques for detecting the location of transition. The disturbance levels were measured by using hot wire anemometry and pressure transducers. The transition Reynolds numbers obtained from the tests correlated well when the fluctuating pressures measured at the surface of conical models were used as a correlating parameter
    • …
    corecore