Advanced high-temperature electromagnetic pump

Three phase helical, electromagnetic induction pump for use as boiler feed pump in potassium Rankine-cycle power system is described. Techniques for fabricating components of pump are discussed. Specifications of pump are analyzed

Hydrogen detection study

The effectiveness was assessed of a hydrogen (H2) detection concept for regenerative environmental control life support systems (EC/LSS). The concept evaluated was that utilized for the electrochemical depolarized concentrator (EDC) design, constructed, and tested for the EC/LSS space station prototype program. The EDC contains combustible gas detectors (CGDs) which were evaluated with H2. The CGDs were evaluated for linearity, position sensitivity, reproducibility, ambient effects, repeatability, speed of response, recovery time, and interchangeability. The effectiveness of CGDs located within the EDC for sensing H2 leaks at various line replaceable units in the subsystem was determined. The effects of H2 leak rate, H2 concentration of leaking gas and air currents in the vicinity of the EDC were determined. Proposed improvements for the H2 detection concept were documented and alternative H2 detection approaches were identified and analyzed

Detection of nanoparticles by means of reflection electron energy loss spectroscopy depth profiling

The various studies of nanoparticles are of great importance because of the wide application of nanotechnology. The shape and structure of the nanoparticles can be determined by transmission electron microscopy (TEM) and their chemistry by electron energy loss spectroscopy. TEM sample preparation is an expensive and difficult procedure, however. Surface sensitive, analytical techniques, such as Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS) are well applicable to detect the atoms that make up the nanoparticles, but cannot determine whether particle formation occurred. On the other hand, reflection electron energy loss spectroscopy (REELS) probes the electronic structures of atoms, which are strongly different for the atoms being in solution or in precipitated form. If the particle size is in the nm range, plasmon resonance can be excited in it, which appears as a loss feature in REELS spectrum. Thus, by measuring AES (XPS) spectra parallel with those of REELS, besides the atomic concentrations the presence of the nanoparticles can also be identified. As an example, the appearance of nanoparticles during ion beam induced mixing of C/Si layer will be shown

High temperature electronic requirements in aeropropulsion systems

The needs for high temperature electronic and electro-optic devices as they would be used on aircraft engines in either research and development applications, or operational applications are discussed. The conclusion reached is that the temperature at which the devices must be able to function is in the neighborhood of 500 to 600 C either for R&D or for operational applications. In R&D applications the devices must function in this temperature range when in the engine but only for a moderate period of time. On an operational engine, the reliability requirements dictate that the devices be able to be burned-in at temperatures significantly higher than those at which they will function on the engine. The major point made is that semiconductor technology must be pushed well beyond the level at which silicon will be able to function

Analysis of the staging maneuver and booster glideback guidance for a two-stage, winged, fully reusable launch vehicle

One of the promising launch concepts that could replace the current space shuttle launch system is a two-stage, winged, vertical-takeoff, fully reusable launch vehicle. During the boost phase of ascent, the booster provides propellant for the orbiter engines through a cross-feed system. When the vehicle reaches a Mach number of 3, the booster propellants are depleted and the booster is staged and glides unpowered to a horizontal landing at a launch site runway. Two major design issues for this class of vehicle are the staging maneuver and the booster glideback. For the staging maneuver analysis, a technique was developed that provides for a successful separation of the booster from the orbiter over a wide range of staging angles of attack. A longitudinal flight control system was developed for control of the booster during the staging maneuver. For the booster glide back analysis, a guidance algorithm was developed that successfully guides the booster from the completion of the staging maneuver to a launch site runway while encountering many off-nominal atmospheric, aerodynamic, and staging conditions

Internationalization of vocational and higher education systems: A comparative-institutional approach

This paper sketches a comparative-institutional approach that seeks to enhance our understanding of internationalization and the resultant national dynamics of institutional change in vocational and higher education systems. Focusing on change at the nexus of general and vocational skill formation institutions, we discuss shifts in the relationship between higher education and vocational training systems. How are such national systems responding to the exogenous pressures of international diffusion and Europe-wide Bologna and Copenhagen processes more specifically? Changes in the competition between the differentially institutionalized organizational fields of general and vocational education also imply the adjustment of individual pathways, participation rates, and life chances. Three complementary studies serve to compare and contrast the transformation of Germanys vocational and higher education systems. The comparison of Germany, Great Britain and the United States analyzes the diffusion and cross-national transfer of educational models in specific historical periods. To highlight different national responses to internationalization and Europeanization, Germany will also be compared with Switzerland and Austria as well as with France. If the first study charts primarily the origins of models to be emulated because of their global salience (cultural-cognitive dimension), then the second and third comparative studies analyze the normative and regulative dimensions, showing the consequences of institutional change processes for the on-going competition between these organizational fields. -- Dieses Papier versucht darzulegen, welche Forschungsleitfragen, theoretischen Zugänge und welches Forschungsdesign für eine Untersuchung von Internationalisierung und nationalen Veränderungsdynamiken von Berufsbildungs- und Hochschulsystemen in Ansatz zu bringen sind. Gegenstand des vergleichenden Forschungsprojekts ist die Untersuchung des institutionellen Wandels an den Schnittstellen von höherer Allgemein- und beruflicher Bildungmit der Perspektive auf Veränderungen im beruflichen Bildungssystem. Welche Veränderungen ergeben sich im Berufsbildungssystem und seinem Verhältnis zum System der höheren Allgemeinbildung durch den exogenen isomorphen Veränderungsdruck, etwa durch Bologna und Kopenhagen? Mit detaillierten Analysen der nationalen Bildungsstrukturen und -pfade werden gegenwärtige Veränderungsprozesse und -dynamiken untersucht. Von zentraler Bedeutung sind dabei Aspekte des Wettbewerbs zwischen den beiden unterschiedlich institutionalisierten und organisierten Bildungsbereichen. Ferner werden die Implikationen des festgestellten institutionellen Wandels für die Beteiligung der Individuen an höherer Allgemein- und beruflicher Bildung eruiert. Die Ländervergleiche dienen als Kontrastfolien für den Wandel des deutschen Berufsbildungssystem: Deutschland wird in den drei vergleichenden Projekten mit den USA und Großbritannien, der Schweiz und Österreich sowie Frankreich verglichen. Ziel dieser Ländervergleiche ist es, Institutionalisierungs- und Europäisierungsprozesse der kulturell-kognitiven, normativen, und regulativen Dimensionen zu analysieren und damit den Wettbewerb dieser organisatorischen Felder aufzuzeigen.

Space infrared telescope pointing control system. Automated star pattern recognition

The Space Infrared Telescope Facility (SIRTF) is a free flying spacecraft carrying a 1 meter class cryogenically cooled infrared telescope nearly three oders of magnitude most sensitive than the current generation of infrared telescopes. Three automatic target acquisition methods will be presented that are based on the use of an imaging star tracker. The methods are distinguished by the number of guidestars that are required per target, the amount of computational capability necessary, and the time required for the complete acquisition process. Each method is described in detail

Cryogenic thermocouple calibration tables

Thermocouple calibration standards are developed for low-temperature thermocouple materials. Thermovoltage, thermopower, and the thermopower derivative are presented in tabular and graphical form

Johnson, Magdalena: Schulische Inklusion in den USA – ein Lehrbeispiel für Deutschland? Eine Analyse der Vermittlung von Ansätzen der Inklusion durch die Zusammenarbeit mit einem outside change agent. Bad Heilbrunn: Klinkhardt 2013. [...] [Sammelrezension]

Rezension von: 1. Magdalena Johnson: Schulische Inklusion in den USA – ein Lehrbeispiel für Deutschland? Eine Analyse der Vermittlung von Ansätzen der Inklusion durch die Zusammenarbeit mit einem outside change agent. Bad Heilbrunn: Klinkhardt 2013, 244 S. ISBN 978-3-7815-1892-6. 2. Andreas Köpfer: Inclusion in Canada. Analyse inclusiver Unterrichtsprozesse, Unterstützungsstrukturen und Rollen am Beispiel kanadischer Schulen in den Provinzen New Brunswick, Prince Edward Island und Québec. Bad Heilbrunn: Klinkhardt 2013, 290 S. ISBN 978-3-7815-1917-

Cryogenic thermocouple tables

Cryogenic standardized thermocouple materials table