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[en] The high-dose ion ion implantation followed by a thermal-annealing step represents a flexible most promising procedure for the synthesis of buried nanocrystals in a solid. The processes of the structure formation in the solid matrix are however much more complicated compared with chemical-reaction slopes in solution. The first aim of this thesis consisted in the finding of the explanation for the unusual structure formation in the case of CdSe in SiO2. Thereby a computer simulation was established, which allowed to meet qualitative conclusion regarding a relatively low number of simulation parameters. Thereby it dealt with a particle-Monte-Carlo simulation. Under inclusion of usually neglected factors, here the alteration of the matrix during the implantation and the role of defects in the segregation formation in amorphous SiO2, for the first time a consistent explanation both for the generation of nanocrystal bands in the depth and for the structures in the implanted region could be given. Furthermore it was studied how far the buried CdSe nanocrystals can be doped with sulfur. As it could be shown the ion-beam synthesis represents a suitable procedure in order to synthetisize buried CdSxSe1-x mixed crystals on the base of purely solid-state processes in SiO2. The third aim of this thesis consisted in the discussion of an alternative non-thermal tempering behaviour on the base of pulsed laser radiation
Source
2006; 166 p; Mensch and Buch; Berlin (Germany); ISBN 978-3-86664-125-9; 
; ISBN 3-86664-125-7; ; Diss.
; ISBN 3-86664-125-7; ; Diss.
No abstract available
Journal
Schweizer Archiv fuer Tierheilkunde (Print); ISSN 0036-7281; ; v. 130(4); p. 167-183
; v. 130(4); p. 167-183
[en] In a referendum held in Switzerland on September 23, 1984, the initiative of a future without more nuclear power plants was rejected. The initiative had demanded that no more nuclear power plants were to be build and existing ones were not to be replaced. Two other popular votes were held about the uses of nuclear power on September 23, 1990. The opting-out initiative was rejected with 53% of the votes, while the moratorium initiative (no permits for new nuclear power plants for a period of ten years) was carried with 55% of the votes. This result shows that the Swiss population is not prepared at present to accept new nuclear power plants, but considers the existing plants necessary. Under these conditions it is difficult to guarantee a sufficient supply of electricity, as electricity consumption is expected to rise annually up until the year 2000. The Swiss power economy therefore has made use of the opportunity to acquire options to purchase nuclear electricity in France. In addition to the Swiss domestic nuclear capacity of 2950 MW, an option for 2550 MW has been bought from the French nuclear park. (orig.)
[de]
Am 23.9.84 wurde in der Schweiz in einer Volksabstimmung die Initiative fuer eine Zukunft ohne weitere Atomkraftwerke abgelehnt. Diese verlangte, dass keine weiteren Kernkraftwerke mehr gebaut und bereits bestehende Anlagen nicht mehr ersetzt werden duerften. Am 23.9.90 fanden zwei weitere Volksabstimmungen ueber die Nutzung der Kernenergie statt. Dabei wurde die Ausstiegsinitiative mit 53% der Stimmen verworfen. Hingegen wurde die Moratoriumsinitiative (10jaehriger Bewilligungsstopp fuer neue Kernkraftwerke) mit 55% Ja-Stimmen angenommen. Dieses Resultat zeigt, dass das Schweizervolk gegenwaertig nicht bereit ist, neue Kernkraftwerke zu akzeptieren, aber die bestehenden Anlagen als notwendig erachtet. Die Gewaehrleistung einer genuegenden Elektrizitaetsversorgung gestaltet sich unter diesen Umstaenden als schwierig, da bis zum Jahr 2000 mit einer jaehrlichen Zunahme des Elektrizitaetsbedarfs zu rechnen ist. Die schweizerische Elektrizitaetswirtschaft hat schon frueh die Moeglichkeit wahrgenommen, sich in Frankreich Bezugsrechte fuer Atomstrom zu sichern. Zusaetzlich zur inlaendischen Nuklearkapazitaet von 2950 MW hat sie aus dem franzoesischen Nuklearpark 2550 MW an Bezugsrechten erworben. (orig.)Journal
No abstract available
Journal
Transactions of the American Nuclear Society; ISSN 0003-018X; ; v. 47 p. 25
; v. 47 p. 25
[en] With high resolution computed tomography (CT) of the skull, performing rapid series of 1.5 mm slices during an intravenous bolus injection of contrast medium, an angiography-like image (Angio-CT) of the basal cerebral arteries can be obtained. From 76 consecutive angiographically or autopsy-verified cerebral aneurysms of various size down to 3 mm in diameter, 74 (97.4%) were shown up by the Angio-CT. One ruptured and one incidental aneurysm escaped CT visualization. Besides the correct localization of the aneurysms, Angio-CT provides information concerning the size and main direction of the aneurysms and yields, in addition, a coronal view of the aneurysms and their surrounding structures. Pitfalls for mis-diagnosis can be the following: aneurysms of below 5 mm in diameter, located at the supraclinoid part of the carotid artery, multiple or non-ruptured aneurysms, bony or movement artefacts, poorly contrasted vessels due to wrong injection technique of contrast medium, and incorrect interpretation. (orig.)
Journal
[en] Ten patients with suspected abnormalities or thrombosis of the superior sagittal sinus were studied by high resolution computed tomography using a thin slice technique after bolus injection. In all patients good visualization of the sinus pathology could be achieved, which correlated exactly with the findings in the 7 angiographically controlled cases. (orig.)
Journal
[en] 10 patients with an AVM of the brain were examined by magnetic resonance angiography (MRA), magnetic resonance imaging (MRI) and conventional cerebral angiography (CCA). From MRA in 7/10 patients important information about vascular supply could be provided; in 3 patients, all with small AVM's it could be only suspected. CCA revealed the vascularisation of the AVM's in all patients and showed additional hemodynamic aspects better than MRA. With MRI in all cases the AVM could be diagnosed, but only the involvement of the main cerebral vessels could be demonstrated; however, MRI is superior to MRA and CCA in showing the nidus and the involved brain structures. (orig.)
Journal
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