Wet gas measurement

A first apparent property of a multi-phase process fluid is determined based on the motion of the vibratable flowtube. One or more apparent intermediate values associated with the multi-phase process fluid are determined based on the first apparent property. A measure of wetness of the multi-phase process fluid is determined based on a mapping between one or more of the apparent intermediate values and the measure of wetness. A second apparent property of the multi-phase process fluid is determined using the differential pressure flowmeter. One or more phase-specific properties of the multi-phase process fluid is determined based on the measure of wetness and the second apparent property

Verfahrenskombination aus Gaspermeation und Kondensation zur Abtrennung und Rueckgewinnung organischer Daempfe aus Abgasstroemen

In dieser Arbeit wurde die Kombination aus Gaspermeation und partieller Kondensation als neues Verfahren zur Reinigung loesemittelbeladener Abgasstroeme bei gleichzeitig schonender Rueckgewinnung der fluessigen Wertstoffe untersucht. Aufbauend auf den experimentellen Ergebnissen gelang die Erweiterung vorhandener Modellvorstellungen, deren Integration in neu entwickelten Rechenprogrammen nunmehr auch die verantwortliche verfahrenstechnische Auslegung des genannten Hybridverfahrens ermoeglicht. (orig.)The combination of gaspermeation and partial condensation as a new process to separate and recover organic vapours from waste gas streams has been studied. Results from experimental investigations under laboratory as well as technical conditions provide the basis for enlargement of existing theoretical models. New calculation programs, which facilitate reliable design of this hybrid process, have been developed. (orig.)Available from TIB Hannover: RA 3251(94/E/48) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Messung binaerer Diffusionskoeffizienten von Gasen in Wasser mit Hilfe der holographischen Interferometrie

The mass diffusion coefficient of gases in liquids is of high interest in deep diving technology, where divers have to be supplied with artificial breathing gases. Diffusion coefficients of oxygen, helium and nitrogen in pure water are determined at pressures up to 50 bar and temperatures between 10 and 30 C. The described measurement method is based on online holographic interferometric techiques. A digital imaging processing system is used to monitor the transient mass diffusion process. The measurement cell is developed to allow measurements over a wide temperature and pressure range. A new evaluation method is developed in which no initial and boundary conditions, not even any kind of calibaration are needed. The results which are able to be reproduced are compared with data from the literature. Good agreement is observed. (orig.)Available from TIB Hannover: RA 3251(95/E/55) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Theoretische Untersuchungen zur Bestimmung des kavitationsfreien Primaerdurchsatzes nach Kernkompaktierung des Reaktors FRG-1

Auf der Basis einer umfangreichen Analyse des Einflusses einer Kernkompaktierung des Reaktors FRG-1 auf die Aenderung der Stroemungs-, Waermeaustausch- und Kavitationsverhaeltnisse im Reaktorkuehlkreislauf wurden theoretische Grundlagen der Vorgehensweise zur Bestimmung des kavitationsfreien Primaerdurchsatzes entwickelt. Es wurde nachgewiesen, dass das Problem komplex, d.h. unter Beruecksichtigung der gegenseitigen Kopplung von Stroemungs-, Temperatur- und Kavitationsfeldern betrachtet werden muss und, dass es zur erfolgreichen Loesung der Aufgabe noch unbedingt erforderlich ist, parallel eine optimale Festlegung der Hauptprimaerumwaelzpumpe herbeizufuehren. (orig.)Basing on an extensive analysis of the influence of compacting the FRG-1 reactor core upon the change in flow, heat exchange, as well as cavitation behavior of the primary circuit the underlying principles of the determination procedure for a cavitations-free primary flow have been developed theoretically. It was found that the problem has to be treated in a complex manner, i.e. considering the coupled flow, temperature, as well as cavitation fields, and that for a successful solution of the problem it is absolutely necessary to simultaneously induce an optimized fixation of the main primary coolant pump. (orig.)SIGLEAvailable from TIB Hannover: RA 3251(97/E/27) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Aufbereitung kontaminierter Schluffe - Untersuchungen zur Feststoffabscheidung mit Zyklonen

The influence of cyclone design and operation mode upon flow behaviour, pressure drop, and collection efficiency of two cyclones is analized systematically by means of numerical calculations. It turns out that the cyclone design can be optimized concerning its geometrical form and operational behaviour and that the parameters pressure, temperature, flow rate, and particle load influence especially the separation behaviour, provided the particle size distribution as well as the fractional efficiencies are known. Generally the calculational results show a stable operation and a high seperation rate of both cyclones. (orig.)SIGLEAvailable from TIB Hannover: RA 3251(95/E/68) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

An algorithm for solving non-linear problems in mechanics of structures under complex loading histories

An algorithm in the framework of the Large Time Increment method is presented. This computational algorithm allows to deal with non-linear material behaviour, such as plasticity and viscoplasticity, for quasi-static problems under cyclic loading histories. The method differs from the common integration methods because it is an iterative method which takes into account the whole loading history in one single increment at once. A significant advantage of this algorithm is that no hypothesis of the interpolation time functions is needed. At each iteration, these functions depend on material properties algorithm parameters and previous iterations. (orig.)SIGLEAvailable from TIB Hannover: RA 3251(99/E/70) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

The current state and future direction of numerical models in simulating atmospheric long-range transport of heavy metals over Europe A review

In view of the decision of the United Nations-Economic Commission Europe (UN-ECE) to prepare a protocol for heavy metals and persistent organic pollutants under its Convention on Long-range Transboundary Air Pollution an attempt is made to summarize European activities on modeling the atmospheric long-range transport of heavy metals. Special emphasis is placed on mercury, lead and cadmium which have been defined by the UN-ECE to be the priority heavy metals of concern. In this paper, numerical models for atmospheric transport, transformations and deposition of heavy metals are discussed chronologically with respect to their development and first applications. Basic features of the models together with input data and main results are summarized in a table. Limitations of present models and the improvements that are needed to address effectively the issues presently facing the atmospheric scientific and policy-making communities are briefly outlined. (orig.)In Anbetracht der Entscheidung der Vereinten Nationen-Wirtschaftskommission Europa (UN-ECE), im Rahmen der Konvention zum grenzueberschreitenden Transport von Luftschadstoffen ein Protokoll fuer Schwermetalle und persistente organische Verbindungen vorzubereiten, werden die europaeischen Aktivitaeten zur numerischen Modellierung des grossraeumigen atmosphaerischen Transports von Schwermetallen zusammenfassend dargestellt. Besonderes Augenmerk wird auf Quecksilber, Blei und Cadmium gerichtet, die von der UN-ECE als prioritaer eingestuft worden sind. In der vorliegenden Arbeit werden die numerischen Modelle fuer atmosphaerische Transporte, Transformationen und Depositionsfluesse von Schwermetallen in der chronologischen Reihenfolge ihrer Entwicklung und ersten Anwendungen diskutiert. Die Hauptauslegungsmerkmale der Modelle sowie die erforderlichen Eingabedatensaetze und die wichtigsten Ergebnisse sind in einer Tabelle zusammengefasst. Einschraenkungen, denen die derzeit verfuegbaren Modelle unterliegen, sowie Verbesserungsforderungen, die aus Kreisen der Wissenschaft und der politischen Entscheidungstraeger gestellt worden sind, werden in kurzer Form beschrieben und bewertet. (orig.)Available from TIB Hannover: RA 3251(96/E/73) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Strukturuntersuchungen am 70S-Ribosom von E.coli unter Anwendung von Neutronenstreuung

Ribosomes are ribonucleo-protein complexes, which catalyse proteinbiosynthesis in all living organisms. Currently, most of the structural models of the prokaryotic 70S ribosome rely on electron microscopy and describe mainly the outer shape of the particle. Neutron scattering can provide information on the internal structure of the ribosome. Parts of the structure can be contrasted for neutrons by means of an isotopic exchange of the naturally occurring hydrogen ("1H) for deuterium ("2H), allowing direct measurements in situ. Specifically deuterium-labeled ribosomes (E. coli) were prepared and analysed with neutron scattering. The biochemical methods were established and combined to a generally applicable preparation system. This allows labeling of all ribosomal components in any combination. A systematic analysis of the protein and RNA phases resulted in the development of a new model for the 70S ribosome. This model describes not only the outer shape of the particle, but displays also an experimentally determined internal protein-RNA distribution and the border of subunits for the first time (four-phase model; resolution: 50A). Models of the 70S ribosome from other studies were evaluated and ranked according to consistency with the measured scattering data. Applying a new neutron scattering technique of particular sensitivity, the proton-spin contrast-variation, single proteins could be measured and localized. The positions of the proteins S6 and S10 were determined, providing the first coordinates of protein mass centers within the 70S ribosome. (orig.)Ribosomen sind Ribonukleinsaeure-Protein Komplexe, die in allen lebenden Organismen die Proteinbiosynthese katalysieren. Strukturmodelle fuer das prokaryontische 70S-Ribosom beruhen derzeit vorwiegend auf elektronenmikroskopischen Untersuchungen und beschreiben im wesentlichen die aeussere Oberflaeche des Partikels. Informationen ueber die innere Struktur des Ribosoms koennen Messungen mit Neutronenstreuung liefern. Durch den Austausch des natuerlichen Wasserstoffs ("1H) gegen Deuterium ("2H) lassen sich Teilstrukturen des Komplexes fuer Neutronen kontrastieren und direkt in situ vermessen. Im Rahmen der vorliegenden Arbeit wurden solche deuterium-markierten Ribosomenpraeparate (E. coli) hergestellt und mit Neutronen analysiert. Die erforderlichen biochemischen Methoden wurden etabliert und zu einem allgemein anwendbaren Praeparationssystem zusammengefasst. Es koennen damit alle Komponenten des 70S-Ribosoms in beliebiger Kombination markiert werden. Auf der Grundlage einer systematischen Analyse der Protein- und RNA-Phasen konnte ein neues 70S-Ribosomenmodell entwickelt werden, das nicht nur die aeussere Form des Partikels beschreibt, sondern erstmals auch eine vermessene interne Protein-RNA-Verteilung und den Verlauf der Untereinheitengrenze angibt (Vierphasen-Modell; Aufloesung: 50 A). 70S-Ribosomenmodelle aus anderen Studien wurden anhand der gemessenen Streudaten beurteilt und gewichtet. Mit Hilfe einer neuen, besonders empfindlichen Neutronenstreutechnik, der Protonenspin-Kontrastvariation, gelang es ausserdem, einzelne markierte Proteine zu vermessen und zu lokalisieren. Mit den Positionen von S6 und S10 werden die ersten im 70S-Ribosom vermessenen Proteinschwerpunktskoordinaten vorgelegt. (orig.)Available from TIB Hannover: RA 3251(97/E/62) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Mechanismen der Legierungsbildung beim mechanischen Legieren in Systemen mit positiver Mischungsenthalpie

The most outstanding feature of mechanical alloying, a young and powerfull tool for powder-metallurgical production of alloys, is the formation of solid solutions upon processing being far from equilibrium state. Both, metastable as well as unstable solid solutions can be produced by this method. In contrast to the formation of metastable alloys the production of homogeneous solid solutions with positive Gibbs energies must be forced by the milling process against counteracting driving forces. Prior to the alloy formation the elemental ductile components are distributed on an extremely fine lamellar microstructure. When the lamellar spacing is reduced to a critical value, that depends on the phase stabilities and the overall composition of the components, by plastic deformation of powder particles, the extremely high density of grain boundaries is reduced by the formation of composites consisting of coherent regions via recrystallization. Further milling leads to subsequent refinement of these regions by plastic deformation considerably enhancing the stored energy in the interphase interfaces. Supported by the gain of configurational entropy this destabilizes the coherent phase composites relative to the solid solution, which forms after a critical domain size is reached, that depends on the heat of mixing. (orig.)SIGLEAvailable from FIZ Karlsruhe / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman