No abstract available

[en] The acceptance of the peaceful use of nuclear power in society - that is the top of the icemountain of the problem of high technology acceptance at all. Facts like the further growing number of human beings and the call for compatibility with environment make it necessary to use progressive technologies and especially to use nuclear power. Social, psychological and moral factors as fear and special value scales act against this aim. We think of value scales which are correlated to archaic behaviour modes but which are present in modern society in form of socalled green-alternative ideologies. The results of the study are that offensive public relation work is necessary which includes not only information but also overcoming scare, formation of trust and confidence and 'ethical argumentation' in dialog and communication in the field of value scales. In this way a new and broad consensus about nuclear power could be reached. (orig.)

[en] The blanket conceptions of fusion and hybrid reactor projects are presented, as far as the understanding of neutronics and the achieved progress is concerned. The problem of the interaction of 14 MeV neutrons with Li compounds, U-238 and/or Th-232, neutron multiplicators (preferably Be and Pb) and reflectors is discussed. Two effects causing strong deviations from ENDF/B-IV data have been mentioned: 1) cross sections of 7Li(n, n'α)T reaction; 2) neutron multiplication of Pb. The accuracy of neutron data are not regarded separately from the efforts for sophisticated calculational methods. Many of the blanket configurations have complex material composition and complicated geometry. 2 tabs., 6 refs

[en] In underground coal mines, methane gas, if present in sufficient concentration, may be ignited by sparks from hot spots on the picks of coal cutting machines striking hard bands of rock. During the coal cutting, wear-flat areas develop on the trailing side of the tips of picks. As pick wear progresses, the generation of frictional heat and coal dust increases and the development of hot spots at the cutting tips may lead to an explosion of methane gas. Field experience and research work over the last few years have facilitated excellent cutting performance for certain picks through the optimisation of the cutting parameters. Such performance improvements show great promise in preventing the incidence of gas or dust explosions occurring at the coal face area. This study sets out some of the fundamentals of pick geometry and cutting parameters and the methods which have been employed to achieve improvements in reducing the hazards of gas or dust explosions. It is based on the comparative trial results of two types of picks with different designs and on a range of available research information on the subject. My investigation looked at the fundamentals of pick geometry and cutting parameters and the current suppression techniques in place to control the dust and gas explosions on the coal operating face.

[en] Purpose/Objective: Radioimmunotherapy (RIT) has demonstrated promising results in the treatment of chemotherapy refractory non-Hodgkin's lymphoma. The radiation associated with this therapy is emitted in a continuous fashion at low dose rates (LDR). Results from studies comparing the relative efficacy of LDR radiation and high dose rate (HDR) radiation on malignant cell killing have been variable. This variability may be due in part to the relative contribution of different mechanisms of cell killing (apoptosis or necrosis) at different dose rates. Materials and Methods: In order to test this hypothesis, the relative efficacy of LDR (16.7 cGy/hr) and HDR radiation (422 cGy/min) were compared using a human B cell lymphoma cell line (PW) and a PW clone (c26) stably transfected to overexpress the anti-apoptotic gene Bcl-2. The endpoints evaluated included the relative amount of cell killing, the fraction of cell killing attributable to apoptosis versus necrosis, and the impact of Bcl-2 overexpression on both overall cell killing and the fraction of killing attributable to apoptosis. Results: HDR and LDR radiation resulted in similar overall cell killing in the PW wild type cell line. In contrast, killing of clone c26 cells was dose rate dependent. One third less killing was seen following LDR irradiation of c26 cells compared with equivalent doses of HDR radiation. Analysis of the relative mechanisms of killing following LDR irradiation revealed a relative increase in the proportion of killing attributable to apoptosis. Conclusion: These findings support the hypothesis that in PW cells, LDR radiation appears to be highly dependent on apoptosis as a mechanism of cell death. These findings may have implications for the selection of patients for RIT, and for the treatment of tumors that overexpress Bcl-2. They may also help form the basis for future rational design of effective combined modality therapies utilizing RIT

[en] In the present report the role of the fission-fusion hybrid reactor in nuclear power generation is enlightened. Some characteristics of reactor physics studies with 14-MeV neutrons (fusion neutronics) are given. The features of fusion neutronics concerned with the requirements to nuclear data and calculation techniques are mentioned. Experimental methods and their application to blanket models of fusion and fission-fusion hybrid reactors are pointed out. (author)

[en] Starting from the importance of the neutron spectrum as a basic weighting function in reactor physics and engineering, integral methods for determining fast neutron spectra, such as multifoil analysis, as well as differential methods based on recoil proton counters, recoil proton scintillators, ³He or ⁶Li semiconductor sandwich spectrometers and others are described considering primarily publications of the last five years. Finally, the wide and manyfold uses of neutron spectrometry in various fields of reactor and neutron physics are mentioned. (author)

[en] For a thick lead sphere one obtains an almost saturated value for the 14-MeV neutron multiplication factor and, hence, no exact information about nuclear data is available. However, when considering the relation between the leakage spectrum in the 14-MeV neutron peak and in the 1-MeV maximum of the multiplied and inelastically scattered neutrons, a sensitive dependency of σ₂ on the 14-MeV (n, 2n) cross section is obtained. From both the shape of the leakage spectrum and the peak transmission we determined a value of σ₂ = (2.25 ± 0.10) barn for Pb that does not considerably depart from the values of the data libraries ENDF/B-IV and ENDL-82 and gives a contribution to the so far contrary discussion concerned with the multiplying properties of Pb for fusion neutrons. (author)

[en] The progress achieved in neutronic research of fusion and hybrid reactors during the period from 1982 to 1985 is made evident. Some reactor designs are described, particularly the neutron details of their blanket design. Recent fusion-neutronics experiments are treated in more detail. There is an obvious trend from single-material spherical benchmarks which served to verify 14-MeV neutron nuclear data to some more complicated arrangements which will simulate the structural composition of designed blankets. (author)

[en] In the centre of the core configuration BFS-35 of the fast critical assembly BFS-I the neutron spectrum has been measured by means of proton recoil proportional counter spectrometers of the PEI Obninsk and the ZfK Rossendorf. The experimental results have been compared between each other and with the results of calculations in order to estimate the reliability of the measurements and to check different data sets. In general the agreement is rather good. BFS-35 is one of the realizations of the international fast calibration spectrum SCHERZO. Therefore our measurements could be compared with French measurements at the SCHERZO system UK-5 HARMONIE. The experiments at BFS-35 made it possible to measure the SCHERZO spectrum down to energies of about 2 keV. That means a noticeable improvement with regard to the experimental results to be submitted until now. (author)