Development of a Hydrogen-Selective Vacuum Pump on the Basis of Superpermeation = Entwicklung einer auf Superpermeation basierenden, wasserstoffselektiven Vakuumpumpe

In zukünftigen Fusionskraftwerken wird für den Einsatz des „Direct Internal Recycling“ Konzepts (DIR) die Abtrennung von Wasserstoff aus Gasmischungen bei niedrigem Druck in einem Verfahrensschritt benötigt. Nach dem derzeitigen Stand der Technik ist dies bisher nicht möglich. Der Effekt der Superpermeation ist in der Lage die Anforderungen für diesen Prozess zu erfüllen. Darauf basierend wird in der vorliegenden Arbeit eine Prozesseinheit, die Metallfolienpumpe (MFP), entwickelt. Um die Bedeutung der dargelegten Entwicklung aufzuzeigen, werden zunächst die Vorteile des DIR herausgearbeitet. Es ist derzeit keine andere Technologie bekannt, die eine solch bedeutende Verbesserung des Brennstoffkreislaufs von zukünftigen Fusionsreaktoren ermöglicht. Die charakteristische Funktionsweise der MFP wird ausgehend von den grundlegenden physikalischen Abläufen erklärt. Die beeinflussenden Materialeigenschaften werden dabei beschrieben und die relevanten Literaturdaten dargestellt. Basierend auf den erläuterten Vorgängen wird ein dimensionsloses Modell abgeleitet, das die dominierenden Prozesse in der Metallfolie, dem Kernelement der MFP, beschreibt. Aus diesem Modell werden die Limitierungen für die möglichen Folienmaterialien abgeleitet. Mit Hilfe der dargestellten Materialeigenschaften wird die dimensionslose Beschreibung in quantifizierte Aussagen für einzelne Materialien umgewandelt. Auf diese Weise wird gezeigt, dass sich die Metalle Niob und Vanadium am besten für Metallfolienpumpen in Fusionskraftwerken eignen. Die Bildung von Wasserstoffbläschen wird als wichtige Materiallimitierung aufgezeigt und begründet. Im Rahmen dieser Arbeit werden zwei experimentelle Einrichtungen genutzt. Dabei wird eine im Rahmen dieser Arbeiten entworfen, gebaut, in Betrieb genommen und eingesetzt. Die Superpermeation wird erfolgreich mit mehreren Metallfolienmaterialien und Energiequellen für Wasserstoff demonstriert. Diese Energiequellen sind neben der Metallfolie das zweite bedeutende Element einer MFP. Ihr Einsatz ist stark vom gewünschten Saugdruck der Pumpe abhängig. Mehrere Vorhersagen des dimensionslosen Modells werden experimentell nachgewiesen. Basierend auf den experimentellen Ergebnissen wird ein klarer Entwicklungspfad aufgezeigt. Dabei werden die offenen Forschungsfragen und ihr Einfluss diskutiert

The Use of Fuzzy Set Theory in Remote Sensing Pattern Recognition

Satellite images increasingly become a major data source for monitoring changes in the natural environment. A main task in the analysis of satellite images is concerned with the modelling of land use classes by reducing uncertainty during a classification process. In the approach presented in this paper uncertainty is perceived to be due to the vagueness of geographical categories caused by either the complexity of the category (like 'urban area') or by the use of the category in several application contexts. Two circumstances of use of an extended set theoretical concept (fuzzy sets) are discussed. First, two algorithms from the ISODATA class are used to determine the grades of membership to three a priori defined classes (woodland, suburban area, urban area) of a LANDSAT TM satellite image of Vienna, Austria. The results are visualized by a RGB image of the grades of membership to each category. Second, a measure of fuzziness is employed on the results. The measure relies on the concept of distance between a seUcategory and its complement. The so determined vagueness provide more information on the uncertainty of the different categories and may improve further information processing tasks. (authors' abstract)Series: Discussion Papers of the Institute for Economic Geography and GIScienc

Variational Methods in Shape Space

This dissertation deals with the application of variational methods in spaces of geometric shapes. In particular, the treated topics include shape averaging, principal component analysis in shape space, computation of geodesic paths in shape space, as well as shape optimisation. Chapter 1 provides a brief overview over the employed models of shape space. Geometric shapes are identified with two- or three-dimensional, deformable objects. Deformations will be described via physical models; in particular, the objects will be interpreted as consisting of either a hyperelastic solid or a viscous liquid material. Furthermore, the description of shapes via phase fields or level sets is briefly introduced. Chapter 2 reviews different and related approaches to shape space modelling. References to related topics in image segmentation and registration are also provided. Finally, the relevant shape optimisation literature is introduced. Chapter 3 recapitulates the employed concepts from continuum mechanics and phase field modelling and states basic theoretical results needed for the later analysis. Chapter 4 addresses the computation of shape averages, based on a hyperelastic notion of shape dissimilarity: The dissimilarity between two shapes is measured as the minimum deformation energy required to deform the first into the second shape. A corresponding phase-field model is introduced, analysed, and finally implemented numerically via finite elements. A principal component analysis of shapes, which is consistent with the previously introduced average, is considered in Chapter 5. Elastic boundary stresses on the average shape are used as representatives of the input shapes in a linear vector space. On these linear representatives, a standard principal component analysis can be performed, where the employed covariance metric should be properly chosen to depend on the input shapes. Chapter 6 interprets shapes as belonging to objects made of a viscous liquid and correspondingly defines geodesic paths between shapes. The energy of a path is given as the total physical dissipation during the deformation of an object along the path. A rigid body motion invariant time discretisation is achieved by approximating the dissipation along a path segment by the deformation energy of a small solid deformation. The numerical implementation is based on level sets. Chapter 7 is concerned with the optimisation of the geometry and topology of solid structures that are subject to a mechanical load. Given the load configuration, the structure rigidity, its volume, and its surface area shall be optimally balanced. A phase field model is devised and analysed for this purpose. In this context, the use of nonlinear elasticity allows to detect buckling phenomena which would be ignored in linearised elasticity

A perceptual dialectological approach to linguistic variation and spatial analysis of Kurdish Varieties

This paper presents the results of the first investigation into Kurdish linguistic varieties and their spatial distribution. Kurdish dialects are used across five nation states in the Middle East and only one dialect, Sorani, has official status in one of these nation states. The study employs the “draw-a-map” task established in Perceptual Dialectology; the analysis is supported by Geographical Information Systems (GIS). The results show that, despite the geolinguistic and geopolitical situation, Kurdish respondents have good knowledge of the main varieties of their language (Kurmanji, Sorani, and the related variety Zazaki) and where to localize them. Awareness of the more diverse Southern Kurdish varieties is less definitive. This indicates that the Kurdish language plays a role in identity formation, but also that smaller isolated varieties are not only endangered in terms of speakers, but also in terms of their representations in Kurds’ mental maps of the linguistic landscape they live in.</jats:p

Luftkeimbelastung und Lufthygienemanagement in der Schlupfbrut von Masthähnchen als Einflussfaktor auf die Kükengesundheit

Im Rahmen der vorliegenden Arbeit wurde anhand von 30 Schlüpfen von Elterntierherden unterschiedlichen Produktionsalters die Entwicklung von Bioaerosolen während der Schlupfbrut von Masthühnern untersucht. Gesamtkeimzahl, Enterobacteriaceae und Enterokokken stiegen in der Schlupfbrut von Masthuhnküken im Laufe der Schlupfbrut bis hin zur Kükenabnahme signifikant an (p < 0,05). Schimmelpilze konnten in der untersuchten Brüterei nicht nachgewiesen werden. Die Gesamtkeimzahl und Enterokokken stiegen signifikant in Abhängigkeit zum Alter der Mastelterntierherde an. Je älter die Mastelterntierherde war, desto höher war die nachgewiesene Zahl an Mikroorganismen in der Abluft der Schlupfbrut. Ein signifikanter Anstieg (p < 0,05) von Enterobacteriaceae ließ sich bei Altherden (Produktionswoche 24 – 35) beobachten. Ein Biozid auf Wasserstoffperoxid- und Peressigsäurebasis wurde hinsichtlich seines Potentials zur Reduktion von während der Schlupfbrut entstehenden Mikroorganismen anhand von 29 Schlüpfen evaluiert. Gesamtkeimzahl und Enterobacteriaceae konnten durch das Biozid im Mittel aller Untersuchungen signifikant (p 0,05). Die Anwendung des untersuchten Biozids führte in der Folge zu einer nicht signifikanten Reduktion (p > 0,05) des Parameters der 7-Tages Mortalität, jedoch konnte das Biozid den Parameter der 7-Tages-Mortalität auf Maximalwerte von 1% begrenzen. Korrelationen zwischen der mikrobiologischen Belastung in der Schlupfbrut und der 7-Tages Mortalität von Eintagsküken wurden ebenfalls untersucht. Es besteht insgesamt keine signifikante Korrelation zwischen der mikrobiologischen Belastung während der Schlupfbrut von Broilereintagsküken und dem Parameter 7-Tages Mortalität.The aim of this study was to examine microbiological conditions in the exhaust air of hatchers during hatching process of broiler chicklings in a commercial broiler hatchery. Development of bacteria during the hatching process of broiler chickens was observed at 30 chick hatchings of parent flocks with different age. The effect of the application of a biocide based on hydrogen-peroxide and peracetic acid on the development of bacteria during the hatching process of broiler chickens was evaluated at 29 chick hatchings. Examination wether the application of a biocide affects 7-day mortality of broiler chickens or not was performed. Additionally the correlation between microbiological load at pulling time of broiler chickens and 7-day mortality of broiler chicklings was investigated. The development of microorganisms during the hatching process of broiler chicklings was observed. Total bacterial count, Enterobacteriaceae and Enterococci were found in the exhaust air of the hatcher. Bacterial counts of all three rose significantly (p < 0,05) during hatcher phase until pulling of the chicklings. There was no detection of molds in the examined hatchery. Numbers of total bacterial count were elevated significantly dependent on the age of the parent stock flock. The older the parent stock flock, the higher numbers of total bacterial and Enterococci count were found (p < 0,05). Numbers of Enterobacteriaceae were significantly elevated (p < 0,05) in hatcher phases of old parent stock flocks (24th – 35th week of production). Total bacterial count and Enterobacteriaceae were reduced significantly during hatcher phase due to biocide application (p 0,05). The application of the biocide resulted in a reduced parameter of 7-day mortality of the hatched chicklings compared to the control group (p > 0,05). The effect was not significant. However, the biocide application was able to limit the 7-day mortality to maximum values of 1%. Correlations between bacterial counts of Total bacterial count, Enterobacteriaceae and Enterococci and the parameter 7-day mortality of the hatched chicklings were examined. No significant correlation between microbiological condition of the hatcher exhaust air and 7-day mortality was found

USING INERTIAL SENSORS FOR RECONSTRUCTING 3D FULL-BODY MOVEMENT IN SPORTS – POSSIBILITIES AND LIMITATIONS ON THE EXAMPLE OF ALPINE SKI RACING

The present study investigates if inertial sensors could be used for reconstructing 3D full body movements in sports. On the example of alpine ski racing, it was demonstrated that inertial sensors allow computing meaningful parameters related to a skier’s overall posture. While some parameters were obtained with sufficient accuracy and precision, others were not obtained reliably using inertial sensor-based systems. Main error sources were discussed and it was found that an accurate and precise functional calibration is most important for short duration measurements. In cases where it is not possible fixing inertial sensors to all relevant body segments (e.g. skis and arms) their orientations could be estimated. In this case parameter validity needs to be carefully verified, as even strongly related parameters may show different validities, as demonstrated in this study

Visualisation of magnetic domain structures and magnetisation processes in Goss-oriented, high permeability steels using neutron grating interferometry

Industrial transformers cores are built from stacked sheets of an iron silicon alloy, called laminations. The magnetic domain structures of these highly anisotropic electrical steels with a sharp (110)[001]-texture, the so-called Gosstexture, determines the magnetic properties of transformers. Commonly used investigation techniques for these laminations are inductive B-H-measurements. This technique reveals global magnetic properties such as hysteresis, remanence, saturation and losses. Locally resolved information about the underlying domain structure cannot be obtained. In this thesis, the neutron grating interferometer (nGI) is used to investigate the domain structures in Goss-oriented (GO) electrical steels at the Swiss Spallation Neutron Source using the cold neutron imaging facility ICON. In contrast to the attenuation based transmission image, the dark-field image (DFI) is related to multiple refraction of unpolarised neutrons at magnetic domain walls. Thereby the use of the DFI allows for the visualisation of bulk magnetic domain structures in two and three dimensions with a spatial resolution of down to 70 um in a field of view of 64mm x 64mm. The DFI is used for the visualisation of the locally resolved response of the bulk magnetic domain structures under the influence of externally applied magnetic fields. In the first part, the domain formation and growth along the initial magnetisation curve (0-6000 A/m) up to saturation in static DC magnetic fields was studied. For decreasing field values, the visualisation of the recurrence of the hysteretic domain structure down to the remanent (0 A/m) state is given. A correlation of the grain orientation and the corresponding basic and supplementary domain structure is given. In the second part, the DFI is used to investigate the response of magnetic domain walls to dynamic AC magnetic excitations. The visualisation of the domain wall motion under influence of alternating magnetic fields is performed. In detail, scans combining varying levels of an offset DC (0-30 A/m), oscillation amplitude A (0-1500 A/m), and oscillation frequency f (0-200 Hz) are conducted. By increasing the amplitude while maintaining constant values of DC and f, the transition from a frozen domain wall structure to a mobile one is recorded. Vice versa, increasing f while keeping A and DC constant led to the reverse transition from a mobile domain wall structure into a frozen one. It is shown that varying both, A and f shifts the position of transition region. Higher frequencies require higher oscillation amplitudes to overcome the freezing. The DFI allows for the analysis of the laminations coatings impact to the magnetic structures. To visualise the stress effect of the coating to the underlying domain formation an uncoated lamination is investigated with stepwise increasing applied external tensile stresses up to 20MPa. The domain configurations of the intermediate stress states are imaged and the original domain structure of the coated state is reproduced. To verify the results, complementary experiments using Kerr microscopy, Faraday imaging, small-angle neutron scattering and Laue X-ray diffraction were performed. The here presented findings allow for new insights into macromagnetism and enable new approaches in the field of descriptive models for bulk macromagnetism. Furthermore the results have the potential to further improve the properties of GO-steels used in industrial transformer applications

KINETIC AND KINEMATIC COMPARISON OF ALPINE SKI RACING DISCIPLINES AS A BASE FOR SPECIFIC CONDITIONING REGIMES

The purpose of this preliminary case study was to compare the alpine ski racing competition disciplines slalom and giant-slalom with respect to principal kinematics of the lower limbs and the acting forces. Knee angles and ground reaction forces of one high level athlete were determined using inertial sensors and pressure insoles, respectively. Slalom was characterized by a “high dynamic skiing mode” with a distinct “knee angle and loading synchronism” between the inside leg and the outside leg. For giant slalom, a polarized situation was observed: “higher quasi static loads at high knee angles” on the outside leg and “lower eccentric-concentric loads at low knee angles” on the inside leg. These findings may help to increase the specificity of conditioning training and developing more discipline-specific exercises