66,326 research outputs found

    A method for precision anodize stripping

    Get PDF
    Felt templates saturated with etch solution remove anodized finish from aluminum without damage to the surface. The solution is a combination of nitric acid, chromic acid, and hydrofluoric acid

    Germanium coated microbridge and method

    Get PDF
    A superconducting microbridge is provided for use in superconducting quantum interference devices wherein a pair of spaced layers of superconductive material are connected by a weak link bridge to establish an electrical junction. The superconductive layers and bridge are coated with a semiconductor material shunting the bridge at room temperatures to prevent the destruction of the device by minute electrical currents while the coating acts as a dielectric permitting normal electrical behavior of the microbridge at cryogenic temperatures

    The African-American Intellectual of the 1920s: Some Sociological Implications of the Harlem Renaissance

    Get PDF
    This paper deals with some of the sociological implications of a major cultural high-water point in the African American experience, the New Negro/Harlem Renaissance. The paper concentrates on the cultural transformations brought about through the intellectual activity of political activists, a multi-genre group of artists, cultural brokers, and businesspersons. The driving-wheel thrust of this era was the reclamation and the invigoration of the traditions of the culture with an emphasis on both the, African and the American aspects, which significantly impacted American and international culture then and throughout the 20th century. This study examines the pre-1920s background, the forms of Black activism during the Renaissance, the modern content of the writers\u27 work, and the enthusiasm of whites for the African American art forms of the era. This essay utilizes research from a multi-disciplinary body of sources, which includes sociology, cultural history, creative literature and literary criticism, autobiography, biography, and journalism

    Ligand design for site-selective installation of Pd and Pt centers to generate homo- and heteropolymetallic motifs

    Get PDF
    The modular synthesis of a series of nitrogen-rich polydentate ligands that feature a common pincer-type framework is reported. These ligands allow for site-selective installation of palladium and platinum to give rise to bi- and trimetallic complexes that have d^(8)–d^(8) interactions

    Independent Agencies: Government’s Scourge or Salvation?

    Get PDF
    This symposium invites reflection on a number of important questions concerning the independence of the independent regulatory agencies. Three such questions are briefly examined in this essay: First, what is the nature of an independent agency? Second, why should regulatory agencies be independent? Finally, what constrains, and what ought to constrain, an agency\u27s independence? These questions are considered against the backdrop of the legal debate about the constitutional legitimacy of independent regulatory agencies that has been raging since Congress created the first such agency a hundred years ago. The thoughts and conclusions offered in this essay draw on the history and recent experience of the United States Securities and Exchange Commission ( SEC or the Commission ), long recognized as one of the finest independent agencies. I. WHAT IS AN INDEPENDENT REGULATORY AGENCY? An independent regulatory agency is a government entity that frequently exercises executive, judicial and legislative power over a specifically defined area of government interest. In a word, independent agencies are the fourth branch of government, operating separately from but under the oversight or review of the other three. The SEC is a prime example of such an agency. The SEC was established by Congress in 1934. Its enabling legislation is the Securities Exchange Act of 1934 (the 1934 Act). That Act 1 provides that the Commission be composed of five commissioners (including a Chairman) appointed by the President with the advice and consent of the Senate. The commissioners are appointed for fixed terms of ..

    An ab-initio study of the electron-phonon coupling within a Cr(001)-surface

    Get PDF
    It is experimentally well established that the Cr(001)-surface exhibits a sharp resonance around the Fermi level. However, there is no consensus about its physical origin. It is proposed to be either due to a single particle dz2 surface state renormalised by electron-phonon coupling or the orbital Kondo effect involving the degenerate dxz/dyz states. In this work we examine the electron-phonon coupling of the Cr(001)-surface by means of ab-initio calculations in the form of density functional perturbation theory. More precisely, the electron-phonon mass-enhancement factor of the surface layer is investigated for the 3d states. For the majority and minority spin dz2 surface states we find values of 0.19 and 0.16. We show that these calculated electron-phonon mass-enhancement factors are not in agreement with the experimental data even if we use realistic values for the temperature range and surface Debye frequency for the fit of the experimental data. More precisely, then experimentally an electron-phonon mass-enhancement factor of 0.70~0.10 is obtained, which is not in agreement with our calculated values of 0.19 and 0.16. Therefore, we conclude that the experimentally observed resonance at the Cr(001)-surface is not due to polaronic effects, but due to electron-electron correlation effects

    UTD analysis of electromagnetic scattering by flat structures

    Get PDF
    The different scattering mechanisms that contribute to the radar cross of finite flat plates were identified and analyzed. The geometrical theory of diffraction, the equivalent current and the corner diffraction are used for this study. A study of the cross polarized field for a monopole mounted on a plate is presented, using novel edge wave mechanism in the analysis. The results are compared with moment method solutions as well as measured data
    corecore