[en] A deposition method for grain-boundary Josephson contacts based on YBa₂Cu₃O_7-x using biepitaxy has been developed. Prepared layered systems were characterized by means of X-ray diffraction for crystal structure and surface structure analyses. For the Josephson contacts experimental results are given and discussed for iv characteristics, resistive transitions, magnetic field dependence of the critical current, and rf frequency behaviour. Biepitaxial contacts were used to prepare dc SQUIDs. Results are given for the influence of the electric field effect on transport properties at Josephson contacts. A Josepshon FET is discussed

[en] The X-ray tube and the high-tension generator are provided with insulators which together form a high-tension plug connection. By this means the generator casing gets a compact shape. The anode is cooled in a closed cycle by means of oil or water, the cooling pipes being spirally wound around the high-tension generator in the interspace towards the casing. The cooling pipes themselves are cooled in their turn by the air stream of a fan in the casing. Intake and exhaust air flows through slots into and out of the casing (Macrotank G 2000 for shipyards). (DG)

[en] Disaster management is increasingly becoming a project in managing diversity, from cross-organisational collaboration to inclusivity of voices. This is particularly prevalent when dealing with transboundary risks. New information technologies support these transboundary interactions by compiling diverse information and sources to build collaborative insight beyond what any individual organisation can know. This paper explores the ethical concerns that planners and responders face as they work with these collaborative information technologies to engage with data from other organisations, based in different data frameworks, socio-political priorities, goals, and cultures of risk. It draws on the ethical impact assessment of a cross-border collaborative crisis planning platform currently under development in the H2020 project IN-PREP to examine ethical tensions around equity, inclusion, diversity, solidarity, accountability and transparency. It discusses the consequences of such design foci for an agencys ability to notice ethical risks that emerge from working in diversity.

[en] On September 22, 1970, for the first time an accident simulation experiment with complete failure of the forced core cooling and the nuclear shut-down system was performed in the AVR-reactor: Due to a small heat-up of the fuel the nuclear chain-reaction was interrupted and an overheating of the core and structure was prevented due to the natural heat-convection. On the basis of the meanwhile developed computer-methods and accompanying experimental investigations it is now possible to determine exactly the behaviour of the non actively controlled core of the high temperature reactor, and to understand better the course of the AVR-experiments. On the same basis the potential and the limits of the safety conception realized in the AVR with self-stabilization in the case of accident can be determined. Such a small high temperature reactor as for example the HTR-modul of the KWU, which is characterized by a reliable and simple safety-technique with a minimum of expensive active systems, can be realized using a 2-zone-core up to a unit size of nearly 250 MW(th). (orig.)

[en] Automatic translation: This report describes the thermal hydraulic program THERMIX-3D presented in its current form. It should be to the user Provide insight into the structure and functionality of this program system. The focus here is on the description of the input, which contains the structure of the input maps and suggests a method for creating a complete input data set. Furthermore, the structure and meaning of all results of a THERMIX-3D calculation that appear in the output are explained. The Appendix contains some notes and tables which parts understand the program structure and program logic should.

[en] Automatic translation: The temperature and flow processes in the core area of the THTR reactor were measured for the so-called ''5-hour case'' using the 2-dimensional. THERMIX calculation program was examined. The comparison with a 1-dimensional calculation carried out by RWTH Aachen University shows good agreement in the calculated temperatures without the occurrence of local hot spots, despite very different flow conditions in the upper core area. In particular, the heat balance over the core area and thus the gas inlet and outlet temperatures are correct very well matched. However, the maximum ceiling reflector temperature remains 200°C below that in 1-dimensional Value shown on invoice.

[en] Automatic translation: With the help of the 2-dimensional computer program THERMIX, the temperature and flow processes in the core area of the THTR reactor were examined with residual heat removal operation with small mass flow rates either started directly or interrupted for a longer period of time. When NWA operation starts directly, 2% of the full-load mass flow already ensures a stable flow through the core area; when the start is delayed by 5 hours, this is 3%. Lowering the gas inlet temperature has no significant influence the maximum temperatures in the ball fill.

[en] In a continuing discussion concerning the migrating species in Stage III annealing of metals with a fairly compact crystal structure, it is demonstrated that positron annihilation can be used to give information on this problem. The general principle is to measure the recovery of radiation damage in a crystal containing an unbiased sink relative to another crystal where this sink is not present. The consequences of the two models are discussed. It is found that, in molybdenum, vacancies are the migrating species. (author)

[en] When forced cooling is switched off or fails, after the gas paths to the steam generators have been shut down, an intensive natural convection is observed in the core of a pebble-bed reactor. This convection must be investigated at higher temperatures because of the fission product transport it effects and the cooling effect it has in the center of the core. This report describes an appropriate model, the experimental confirmation of this model and its application to the pebble-bed reactor. The expected cooling effect becomes evident in a limitation of the maximum core temperatures. Natural convection in the core is triggered by the rapidly increasing temperature differences between the center of the core and the heat conductive walls resulting from a failure in forced cooling. Figure 1 illustrates this fact with the fictitious temperature change without convective heat transport in the core of the 500 MW/sub th/ pebble-bed reactor PR 500

No abstract available