5,705 research outputs found

    Quantitative absorption and fluorescence studies of NO between 1060 and 2000 A

    Get PDF
    Synchrotron radiation in the 1060 to 2000 A region was used to measure the average absorption and fluorescence cross sections of NO and to determine approximate photodissociation quantum yields. Several vibrational levels of the D(2) sigma(+), E(2) sigma(+), and B(2) delta states have high fluorescence quantum yields. The C(2) and B(2) states do not fluoresce when the excitation energies are above the first dissociation limit, in accord with previous experiments. In general, the fluorescence yields decrease with increasing photon energy. The quantitative measurements are compared with spectroscopic observations and are found to be reasonably consistent

    Quantitative absorption and fluorescence study of CO from 1060 to 1550 A

    Get PDF
    Measurement of the photoabsorption cross section of CO in the 1060-1550 A region using synchrotron radiation is described. The oscillator strengths for the transitions from CO (Chi1Sigma+ to various excited states are obtained from these data. Fluorescence from excited CO was observed in the 1150 to 3000 A and 3000 to 8000 A regions. The quantum yields for the production of fluroescence from the Alpha(1)P and B(1)Sigma(+) states are unity because their excitation energies are below the dissociation limit. The C(1)Sigma(+) , v = O level has significant fluorescence quantum yields both in the UV and visible region, but the yields for the E(1)Pi, v = O and C(1)Sigma(+), v = 1 levels are very small. The C(1)Sigma(+), v = 1 level is presumably predissociated. The cross sections for the production of fluroescence from the a'(3)Sigma(+), d(3)Delta sub 1, e(3)Sigma(-) yields a(3)Pi, and B(1)Sigma(+), C(1)Sigma(+) yields A(1)Pi transitions upon excitation from the X(1)Sigma(+) were measured

    Leading-edge slat optimization for maximum airfoil lift

    Get PDF
    A numerical procedure for determining the position (horizontal location, vertical location, and deflection) of a leading edge slat that maximizes the lift of multielement airfoils is presented. The structure of the flow field is calculated by iteratively coupling potential flow and boundary layer analysis. This aerodynamic calculation is combined with a constrained function minimization analysis to determine the position of a leading edge slat so that the suction peak on the nose of the main airfoil is minized. The slat position is constrained by the numerical procedure to ensure an attached boundary layer on the upper surface of the slat and to ensure negligible interaction between the slat wake and the boundary layer on the upper surface of the main airfoil. The highest angle attack at which this optimized slat position can maintain attached flow on the main airfoil defines the optimum slat position for maximum lift. The design method is demonstrated for an airfoil equipped with a leading-edge slat and a trailing edge, single-slotted flap. The theoretical results are compared with experimental data, obtained in the Ames 40 by 80 Foot Wind Tunnel, to verify experimentally the predicted slat position for maximum lift. The experimentally optimized slat position is in good agreement with the theoretical prediction, indicating that the theoretical procedure is a feasible design method

    Investigation of measures to reduce dog attacks and promote responsible ownership amongst dog owners with dog control issues in the UK

    Get PDF
    The overall aim of the project is to identify methods to reduce dog attacks and dog control issues as well as provide evidence-based recommendations to promote responsible dog ownership amongst owners with dog control issues. The project examined contemporary enforcement practice and also explored risk factors related to dog attacks

    The Impact on U.K. Acquirers of Domestic, Cross-border, Public and Private Acquisitions

    Get PDF
    We examine the announcement and post-acquisition share returns of 4,000 acquisitions by U.K. public firms during 1984-1998. We include acquisitions of domestic and cross-border targets, and of both publicly quoted and privately held targets. In acquisitions of domestic public targets, abnormal returns are negative over both the announcement and post-acquisition period. In acquisitions of cross-border public targets, abnormal returns are zero over the announcement period but negative over the post-acquisition period. In contrast, acquisitions of both domestic and cross-border private targets result in positive announcement returns and zero long run returns. The main difference between private and public acquisitions is that glamour acquirers experience negative announcement and long run returns in public acquisitions, whereas glamour acquirers do not under-perform in private acquisitions. Furthermore, whereas the under-performance of domestic public acquisitions is limited to acquirers using non-cash methods of payment, acquirers of domestic private targets that use non-cash methods do not under-perform. Overall, cross-border acquisitions result in lower announcement and long run returns than domestic acquisitions. In cross-border acquisitions involving high?tech firms both announcement and long run returns are positive, whilst non-high-tech cross-border acquisitions experience zero announcement returns followed by negative long run performance. Our results also suggest that, in cross-border acquisitions, the national cultural difference between the bidder and target countries has a significantly negative impact on long run returns. This paper replaces WP214.Mergers and acquisitions; acquirer share returns; Cross-border targets; private targets

    Making Sense Of Blood-based Proteomics And Metabolomics In Psychiatric Research.

    Get PDF
    This manuscript describes the basics of proteomic and metabolic profiling of blood serum and plasma from patients with psychiatric disorders. It will also explain the rationale behind the use of these body fluids due to need for user friendly and rapid tests in the clinic with simple sampling procedures. It has emerged over the last 15 years or so that psychiatric disorders are whole body diseases and the bloodstream is a means of molecular transport and therefore provides a conduit for two way communication with the brain. Here we also describe some of the basic biomarker findings from studies of serum or plasma from patients with psychiatric disorders like schizophrenia, major depression and bipolar disorder. Finally, we will discuss potential future advancements in this area which includes the development of held devices containing miniature proteomic and metabolic assays which can be used for facilitating diagnosis in a point-of-care setting and yield results in less than 15 minutes from a single drop of blood

    Invariant metrics and Hamiltonian Systems

    Full text link
    Via a non degenerate symmetric bilinear form we identify the coadjoint representation with a new representation and so we induce on the orbits a simplectic form. By considering Hamiltonian systems on the orbits we study some features of them and finally find commuting functions under the corresponding Lie-Poisson bracketComment: 16 pages corrected typos, changed contents (Prop. 3.4 and Theorem in Section 3

    Ensemble Concerts: Chamber Wind Ensemble, February 22, 1976

    Get PDF
    Capen AuditoriumSunday AfternoonFebruary 22, 19762:30 p.m
    • …
    corecore