37,464 research outputs found

    Electronic load for testing power generating devices

    Get PDF
    Instrument tests various electric power generating devices by connecting the devices to the input of the load and comparing their outputs with a reference voltage. The load automatically adjusts until voltage output of the power generating device matches the reference

    Promoting access to primary equity markets : a legal and regulatory approach

    Get PDF
    This paper examines legal and regulatory measures that can be taken to promote access to the primary market in emerging market economies. While capital market development depends on many factors including, primarily, a favorable macroeconomic environment, an appropriately designed and effective legal and regulatory framework can help to encourage market growth and to increase access to finance for all companies, including small- and medium-sized enterprises. In this paper we identify the basic necessities that underpin a regulatory regime that is cost effective and strikes an appropriate balance between, on the one hand, laws and regulations that may be too restrictive to achieve a supply of capital and, on the other, those that may be so relaxed that investors feel that there is an unacceptable level of risk and do not care to venture into the market. We explore the legal foundations for the successful operation of a primary market for securities and identify disclosure and effective monitoring and enforcement as essential elements of legal protection. We then examine different legal and regulatory approaches for improving access to finance. We discuss measures that can be used by traditional stock exchanges to attract smaller enterprises to their lists as well as recent initiatives to create second boards or divide the main board into different market segments. We also discuss different mechanisms for companies to raise funds outside of a formal stock market listing, including private placements and private equity. Finally, we propose some recommendations for a simple legal and regulatory framework that will help promote access to primary equity markets, via both the traditional exchange as well as other alternatives.Markets and Market Access,Economic Theory&Research,Financial Intermediation,CorporateLaw,Investment and Investment Climate

    Consenting agents: semi-autonomous interactions for ubiquitous consent

    No full text
    Ubiquitous computing, given a regulatory environment that seems to favor consent as a way to empower citizens, introduces the possibility of users being asked to make consent decisions in numerous everyday scenarios such as entering a supermarket or walking down the street. In this note we outline a model of semi-autonomous consent (SAC), in which preference elicitation is decoupled from the act of consenting itself, and explain how this could protect desirable properties of informed consent without overwhelming users. We also suggest some challenges that must be overcome to make SAC a reality

    Quantum Lattice Fluctuations and Luminescence in C_60

    Full text link
    We consider luminescence in photo-excited neutral C_60 using the Su-Schrieffer-Heeger model applied to a single C_60 molecule. To calculate the luminescence we use a collective coordinate method where our collective coordinate resembles the displacement of the carbon atoms of the Hg(8) phonon mode and extrapolates between the ground state "dimerisation" and the exciton polaron. There is good agreement for the existing luminescence peak spacing and fair agreement for the relative intensity. We predict the existence of further peaks not yet resolved in experiment. PACS Numbers : 78.65.Hc, 74.70.Kn, 36.90+

    Onset of η\eta-nuclear binding in a pionless EFT approach

    Full text link
    ηNNN\eta NNN and ηNNNN\eta NNNN bound states are explored in stochastic variational method (SVM) calculations within a pionless effective field theory (EFT) approach at leading order. The theoretical input consists of regulated NNNN and NNNNNN contact terms, and a regulated energy dependent ηN\eta N contact term derived from coupled-channel models of the N(1535)N^{\ast}(1535) nucleon resonance plus a regulated ηNN\eta NN contact term. A self consistency procedure is applied to deal with the energy dependence of the ηN\eta N subthreshold input, resulting in a weak dependence of the calculated η\eta-nuclear binding energies on the EFT regulator. It is found, in terms of the ηN\eta N scattering length aηNa_{\eta N}, that the onset of binding \eta\,^3He requires a minimal value of ReaηN\,a_{\eta N} close to 1 fm, yielding then a few MeV η\eta binding in \eta\,^4He. The onset of binding \eta\,^4He requires a lower value of ReaηN\,a_{\eta N}, but exceeding 0.7 fm.Comment: v4 consists of the published Physics Letters B version [31] plus Erratum ([30], Appendix A here); main results and conclusions remain intac

    The scalar complex potential and the Aharonov-Bohm effect

    Full text link
    The Aharonov-Bohm effect is traditionally attributed to the effect of the electromagnetic 4-potential AA, even in regions where both the electric field E\mathbf{E} and the magnetic field B\mathbf{B} are zero. The AB effect reveals that multiple-valued functions play a crucial role in the description of an electromagnetic field. We argue that the quantity measured by AB experiments is a difference in values of a multiple-valued complex function, which we call a complex potential or {pre-potential. We show that any electromagnetic field can be described by this pre-potential, and give an explicit expression for the electromagnetic field tensor through this potential. The pre-potential is a modification of the two scalar potential functions.Comment: 10 pages 2 figure

    A study to determine the flight characteristics and handling qualitites of variable geometry spacecraft. Volume 3: Low L/D concept with fold-down wings

    Get PDF
    A study was conducted to determine the flight characteristics and wing deployment transients for a variable geometry spacecraft concept having a hypersonic lift-to-drag ratio near 1.0, and employing fold-down wings. Unpowered flight conditions were considered throughout the study. The body of the spacecraft uses a trapezoidal cross section. The variable geometry wings, stowed in the sides of the vehicle, are deployed at transonic speeds