[en] In April 1992 at the GSI a prototype experiment on the production and study of the double-magic radioactive nucleus ⁵⁶Ni was successfully performed with proton scattering in inverse kinematics. A 350 MeV/u ⁵⁶Ni primary beam from the heavy ion synchrotron SIS was fragmented in a 4/g/cm² thick beryllium target. The separation of the formed isotopes ensued in the fragment separator FRS, which was operated in the achromatic mode with a degrader. Production cross sections for a whole series of fragments in the range 29≥Z≥19 and 57≥A≥41 were obtained. It succeeded to detect proton-rich isotopes at the boundary of the stability as for instance ⁵²Co, ⁵¹Co, ⁵⁰Co, or ⁵²Ni and to determine for the first time their production cross sections. A further part of this thesis with regard to experiments with radioactive beams were first test experiments at the experimental storage ring ESR. The spotlight held luminosity measurements at the internal gas target with cooled, stable proton beam. For this the elastic scattering was stuided in inverse kinematics in the Rutherford range. Studied were different projectile beams (Ne, Xe) at energies of 150 MeV/u respectively 250 MeV/u and gas jets of nitrogen, argon, and hydrogen. The measured energy spectra of the recoils are in agreement with simulation calculations

[en] Novel electrical heater rods simulating nuclear fuel elements were developed as part of the Light Water Breeder Reactor (LWBR) Development Program to perform tests to confirm predicted thermal and hydraulic characteristics of the LWBR core. These heaters had a heat flux density one order of magnitude greater than commercially available heaters. Reported are the investigations to choose optimum resistance heater materials, insulators, and manufacturing techniques. Although the heater rods developed had operating and lifetime limitations, the task of obtaining the necessary data was accomplished

[en] The method is described of processing an element of a nuclear reactor, the element including a stack of pellets enclosed in a metallic cladding, the method including: positioning the element in a vessel, reducing the pressure of the air in the vessel to a lower magnitude at which there is appreciable oxygen in the atmosphere of the vessel, conducting current through the cladding of the element to elevate the temperature of the cladding, while the cladding is at the temperature introducing gas into the vessel to elevate the pressure in the vessel. The temperature of the cladding reduces the yield strength of the cladding to a magnitude such that the yield strength is exceeded by the elevated pressure and the cladding is collapsed on the pellets of the stack whereby the formation, by exposure to neutron flux, of an unsupported gap in the cladding which would collapse under the pressure and/or at the temperature of the coolant of the reactor is prevented

[en] This paper describes the method of processing a coolant-displacement rod of a nuclear reactor, preparatory to the installation of the rod in the nuclear reactor, to preclude the formation undesirably of an unsupported permanent axial gap in the cladding of the rod over the anticipated time of use of the rod in the nuclear reactor by reason of neutron bombardment of the rod. The gap would be collapsible under the force exerted by the coolant of the nuclear reactor, the rod including a stack of zirconium-oxide pellets in cladding of an alloy of zirconium, the inner surface of the cladding prior to the processing being spaced from the outer surfaces of the pellets. It comprises: mounting the rod in a container and evacuating the container from atmospheric pressure to a pressure such that the rod is in an attenuated atmosphere containing residual oxygen not combined chemically with any other chemical element. Thereafter it conducts electrical current only through the cladding to heat the cladding to a temperature at which the yield strength of the cladding is substantially reduced and, while the rod is maintained at the temperature adding a gas to apply pressure uniformly to the cladding of a magnitude sufficient at the temperature to collapse the cladding uniformly on the outer surface of the pellets of the stack while the rod maintains its radial symmetry. The outer surface of the cladding is oxidized at the temperature by the residual oxygen, the the processing, precluding the formation, by exposure to neutron flux, over the period of time over which the rod will later be in use in a reactor, of an unsupported axial gap in the cladding which would collapse under the pressure and at the temperature, of the coolant of the nuclear reactor

[en] Coronal mass ejections (CMEs) are one of the most energetic processes that occur in our solar system. The resulting interplanetary coronal mass ejections (ICMEs) that propagate through the heliosphere are the strongest drivers of the Earth's space weather system and can induce strong geomagnetic storms that last for multiple days. While the geomagnetic effectiveness of any ICME depends on multiple factors it is primarily determined by the structure of the magnetic field that is carried by the ICME, which is believed to take the form of a twisted magnetic flux rope. In this thesis, we develop the semi-empirical toroidal 3D coronal rope ejection (3DCORE) model for simulating ICME flux ropes and combine it with a Bayesian Monte-Carlo based fitting approach in order to reconstruct in situ magnetic field measurements and gain information on the propagation direction or orientation of the ICME. In the first paper, we showcase how this model is successful in reconstructing the in situ magnetic field measurements for a flux rope observed by the Parker Solar Probe (PSP) spacecraft at the small heliocentric distance of 0.24AU. The results from our model regarding the propagation direction and the orientation of the ICME are also compared with white light images of the same event captured by the STEREO-A spacecraft. We found that certain ICME properties, such as the width to height ratio of the flux rope or the twist of the magnetic field, are difficult or impossible to extract from single magnetic field measurements alone due to projection effects.We further develop novel a multi-point fitting approach in our second paper and apply our model to an ICME event that was observed by three spacecraft, Solar Orbiter, Bepi Colombo, and Wind. We show that is possible to reconstruct the in situ magnetic field observations at two or three locations simultaneously as long as the separations are not too large. For such multi-point events it may then be possible to extract more information on the large-scale structure of ICMEs where single-point measurements are insufficient. In the third paper, we develop an axially deformed cylindrical flux rope model that includes arbitrary curvature and torsion. The developed concepts serve as a foundation for models that want to include ICME deformations due to interactions with the ambient solar wind or the coronal magnetic field. This allows for more complex ICME geometries that are likely necessary to properly analyze multi-point events with spacecraft at larger angular separations. (author)

[en] Lymphoma is frequently present in patients with acquired immunodeficiency (AIDS). But unlike in the general population, the appearance of lymphoma in patients with AIDS is extremely varied. The computed tomographic scans, chest radiographs, and subsequent hospital courses of 15 patients with AIDS-related lymphoma are presented. The patients presented with isolated pleural effusion (six patients), pleural and pericardial effusion (one patient), pulmonary infiltrates (five patients), and mediastinal adenopathy (three patients). This varied manner of presentation of lymphoma in AIDS patients should be recognized if diagnosis is to be made in the earlier stages of presentation

[en] The Division of Theoretical Chemistry at the University of Innsbruck is focused on the study of chemical compounds in aqueous solution, in terms of mainly hybrid quantum mechanical / molecular mechanical molecular dynamics simulations (QM/MM MD). Besides the standard means of data analysis employed for such simulations, this study presents several advanced and capable algorithms for the description of structural and dynamic properties of the simulated species and its hydration. The first part of this thesis further presents selected exemplary simulations, in particular a comparative study of Formamide and N-methylformamide, Guanidinium, and Urea. An included review article further summarizes the major advances of these studies. The computer programs developed in the course of this thesis are by now well established in the research field. The second part of this study presents the theory and a development guide for a quantum chemical program, QuMuLuS, that is by now used as a QM program for recent QM/MM simulations at the division. In its course, this part presents newly developed algorithms for electron integral evaluation and point charge embedding. This program is validated in terms of benchmark computations. The associated theory is presented on a detailed level, to serve as a source for contemporary and future studies in the division. In the third and final part, further investigations of related topics are addressed. This covers additional schemes of molecular simulation analysis, new software, as well as a mathematical investigation of a non-standard two-electron integral. (author)

[en] The transformation and chemical degradation of clay minerals is important with regard to, among others, the reaction of clay minerals in seals of waste disposal facilities. The effect of phosphate and ammonium ions in the leachate on various clay minerals (montmorillonite and kaolinite) has been studied. It was found that clay minerals are transformed to new phases in the presence of leachates that contain phosphate and ammonium ions. The new-formed phases have no or poor sealing properties. As a consequence, these modified clays and clay minerals cannot protect the underlying water table for contamination by leachates from landfills

[en] The paper presents calculations of the evolution of a 20 solar mass star for various assumptions concerning opacities, energy generation, convection, and mass loss. An attempt is made to determine which factors favor a blue supergiant progenitor and which do not. Consideration is given to the reasons for the early evolution of the Sk -69.202 deg. 58 refs

[en] The ⁷⁹Br-NQR spectra of anilinium bromide, C₆H₅NH₃⁺Br^-, of anilinium-d₃ bromide, C₆H₅ND₃⁺Br^-, and of anilinium-d₅ bromide, C₆D₅NH₃⁺Br^-, have been investigated in the temperature range 77<=T/K<=350. The three compounds show an order-disorder phase transition near room temperature. The respective transition temperatures have been determined as 296.9 K (C₆H₅NH₃⁺Br^-), 291.5 K (C₆H₅ND₃⁺Br^-), and 297.6 K (C₆D₅NH₃⁺Br^-). The large value of the ⁷⁹Br-NQR frequency (ν=17.780 MHz at 77 K for C₆H₅NH₃⁺Br^-) and the large ¹H-²D isotopic shift of this frequency (asymptotically equals 400 kHz at 77 K by deuteration of the NH₃⁺-group) have been interpreted in terms of hydrogen bonding N-H--Br^-. The state of order in the high temperature modification is discussed in the light of the ⁷⁹Br-NQR spectrum. The ⁷⁹Br-NQR frequency of the Br^- ion in the low temperature modification is related to the change in the monoclinic angle β and to the temperature dependence of the order parameter s proportional to ((T sub(c) - T)/T sub(c))sup(1/3). (auth.)