Simulationsverfahren fuer Risikoabschaetzungen im Eisenbahn-Mischbetrieb

In general, railway systems belong to those transportation systems with the highest safety level, although accidents happen occasionally. The frequencies of accidents of the german railways and the resulting amount of damages have been decreasing continuously since the nineteenfifties. With the building of the new high speed lines in the eighties a new discussion about safety problems was initiated. This was due to the large number of long tunnels where rescue procedures for accidents are more difficult than on normal track lines. Another risk factor results from mixed operational programs where passenger- and freight trains operate in common. Generally, a procedure is sought to estimate and evaluate risks resulting from arbitrary infrastructures and operational programs. The commonly used risk evaluation model for the new high speed lines is based on the analyse of the probability of the risks of accidents in nuclear power-stations. The main disadvantage of this model, though, is that operational aspects (e.g. the timetable) which could have essential influence on the estimation of the risk value are considered marginaly. Therefore, in this work a procedure is developed, which models the influence of operational programs on risk estimations. The considered parameters are the timetable (including the mixing of various train types and train speeds), the resulting delays (caused by disturbances of the daily operations) and the infrastructure. For the model the railway simulation system SIMU VII was adapted in such a way that informations are collected being relevant for the risk estimations. The main issue of the risk estimation which is analysed with the developed model is to evlauate the probability of endangering a corresponding train (in the other direction) after an accident. In case the corresponding train is not able to stop in time the damage can be increased significantly. The influence of different operation programs or special parameters can now be worked out by the developed model. (orig.)Available from TIB Hannover: RA 3044(46)+a+b / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Global Talent Flow as 'Musical Chairs' : Driving Forces of Young Talents:An Examination of Italy and Lithuania

This Master thesis examines the impact of the individual driving forces of young highly educated talents from Italy and Lithuania to apply for a job abroad after the graduation. By investigating the motivations and influences during this decision-making process, we clarify the role of different impulses on the individual’s decision to become part of the phenomenon known as the global talent flow. Within this study, we obtain the actor’s view, while we use an inductive approach to put the construction of meaning of the participants in the center of our study. This aim of our qualitative study is further strengthened by the use of semi-structured interviews and the usage of the phenomenology approach. The data is analyzed and interpreted according to the emerged themes and linked back to the existing theory on‘migration’, the ‘Push-Pull-Mooring’ paradigm, the ‘gravity’ model, and the knowledge flow according to ‘brain gain’, 'brain drain’, and ‘brain circulation’. This study highlights the variety of facets which are of importance to the individuals within the decision-making process of the non-rational phenomenon of the global talent flow. Although the main motivation - the opportunity to grow - is shared among all participants, a clear distinction can be made between the ‘professional’ and the ‘personal’ growth. Furthermore, our study reveals the direct influence of initiatives taken by the European Union (EU), such as the ERASMUS+ Programme on the mobility of young talents and the impact of possible unforeseen side effects such as the ‘brain drain’ in some of the member countries of the EU. Our findings contribute another layer to the understanding of the driving forces of tomorrow’s mobile workforce to apply for a job abroad. This comprehension is fundamental to policymakers, companies, the society at larger, and the young talents themselves, as it becomes crucial to attract this ‘brain’ to secure long-term development of all stakeholders of the global talent flow within the EU

Multi-crystal analyzer detector system for use as detector in synchrotron for analysis of powders, has beam limiting device, which divides overall beam into individual beams and absorbs scattered radiation

The multi-crystal analyzer detector system has two beam limiting devices, two collimators (2,3) and detectors, which are connected with evaluation devices. The beam limiting device divides an overall beam into individual beams and absorbs the scattered radiation. The beam limiting device comprises a firmly mounted diaphragm with an exchangeable diaphragm (8,11) for each individual beam. The individual beams enter into a collimator path. The former beam limiting device and the former collimator are made of tungsten or tungsten alloys. An independent claim is included for a method for x-ray diffractometry of powders

ELECTRON TRANSFER EFFECT IN INTRINSIC TELLURIUM SINGLE CRYSTALS

Des recherches expérimentales et théoriques concernant le transfert des porteurs et les effets des porteurs chauds en tellure intrinsèque ont été effectuées. Les caractéristiques courant - tension enregistrées au moyen de la technique des impulsions nanosecondes indiquent une résistance différentielle, si l'intensité du champ dépasse une valeur de 3.5 kV/cm. A l'aide de sondes électriques des domaines mouvants de champs intensifs ont été mis en évidence. La vitesse de dérive monte à 7.106 cm/s. Le champ seuil et le coefficient de Hall ont été mesurés aux températures élevées et à une pression hydrostatique. Les résultats indiquent l'existence d'une deuxième bande de conduction, qui se trouve 0.26 - 0.38 eV au-dessus de la première bande, et avec une mobilité des porteurs relativement faible. Les valeurs du champ seuil et de la mobilité électronique, obtenues selon la méthode Monte-Carlo, correspondent bien aux valeurs expérimentales.Experimental and theoretical studies of charge transport and hot carrier effects have been made in intrinsic tellurium. Pulse measurements of current-voltage characteristics have shown a negative differential resistance at fields above 3.5 kV/cm. Moving high-field domains were observed by potential probe measurements. The velocity of the domain was 7.106 cm/s. Hydrostatic pressure measurements of threshold field and Hall coefficient were performed at elevated temperatures, which suggest the existence of a second, low mobility conduction band located 0.26 - 0.38 eV above the first one. Reasonable agreement was obtained between the measured magnitudes of threshold field and electron mobility and the results of Monte Carlo calculations