No abstract available

[en] The subcell structure of a monoclinic low temperature modification of Mg₂NiD₄ was determined from neutron powder diffraction data collected at room temperature. The structure was refined in space group C2/m using the unit cell dimensions a = 6.496(1) A, b = 6.412(2) A, c = 6.602(2) A and β = 93.23(2)⁰. The deuterium atoms form planar quartets around the nickel atoms. The average Ni-D distance d(Ni-D) is 1.557 A. In the superstructure the c axis is doubled. The possible existence of metastable and stable low temperature modifications is discussed. (Auth.)

[en] In order to produce dome-shaped Ge dots with small size and high density, C submonolayers (C-SMLs) were incorporated at the interface between Ge wetting layers and Ge dots. The C atoms are considered to induce a local strain field by forming Ge-C bonding. Such strain field enhanced dome formation even at low temperature (<500 deg. C). Optimization of experimental conditions enabled precise control of the Ge dome size in the range of 30-40 nm with the density of 10¹⁰ cm^-2. The Ge domes thus prepared exhibited intensive photoluminescence (PL) compared to those prepared by a conventional self-assembling technique

[en] Analytically well-characterized soils from four different former manufactured gas plants (MGP) sites contaminated by coal tars were used in tests of extensive biodegradation of polycyclic aromatic hydrocarbons (PAHs) in stirred reactors. In all cases, the extent of biodegradation was limited to 80--100% for 2- and 3-ring PAHs, 40--70% for 4-ring PAHs, and below 20% for 5- and 6-ring PAHs. The capacities to transfer pollutants to water were compared for leachates from soils that had or had not undergone biological treatment. Leachate analysis involved determination of PAHs and bacterial tests of acute toxicity (Microtox) and genotoxicity (SOS Chromotest). For some untreated soils, PAH leaching was observed, and positive responses to the Microtox test were well correlated to the concentrations of naphthalene and phenanthrene. Biologically treated soils had lost all capacities for leaching as concluded from PAH determinations and responses to the Microtox test. All soil leachates were devoid of genotoxic effect, in accordance with the low concentrations observed of mutagenic PAHs. The results of this risk-based approach for assessment of MGP soils showed that pollutants remaining after biological treatment were unavailable for further biodegradation and that the extent of leaching had been reduced to the level that it did not represent a significant threat to groundwater

[en] The relation between the structure of a UO₂ fuel and its mechanical properties are discussed and illustrated for particular types of UO₂ by measurements of fracture surface energy, hardness, fracture stress and of compressive deformation at 1870 and 1970⁰K. This gives the background for treating the question whether it is possible to find a simple experimental method for correlating the mechanical properties of UO₂ before irradiation with those after various irradiation histories. Hardness measurements might be such a method if combined with a detailed structural analysis and sufficient knowledge about the irradiation history

No abstract available

[en] Flow stress, work hardening, stress relaxation, fracture stress, and creep properties of advanced fuels such as (U,Pu)C, carbonitrides, and (U,Pu)N are required to understand their in-pile performance. Besides providing a survey on the deformation properties of these fuels, a second purpose of this paper is to give some initial information on deformation mechanisms in the brittle-ductile range for these plutonium-bearing ceramics of NaCl-type structure. 25 refs

[en] This is a companion paper to the Hughes/Edwards paper presented at EPRI '96, entitled open-quotes Don't Put Your Troubles Down the Drain.close quotes That paper presents a detailed account of liquid radwaste processing performance at Texas Utilities' Comanche Peak Steam Electric Station from 1993 to 1995. This paper looks at the same period from a historical and philosophical (and subjective) perspective

[en] Biodegradation methods are described and discussed with special regard to in-situ methods. In-situ methods normally present the greatest difficulties in terms of the inducement and, especially, the maintenance of optimum degradation conditions at all points of the contaminated ground. To check the success of the measure while under way is hardly possible. (orig.)

[en] Si/Ge multilayer structures formed by the embedding of relatively small amounts of germanium (less then the critical thickness for 3D island formation via Stranski-Krastanow growth mode) in a silicon matrix are obtained by submonolayer molecular beam epitaxy. Structural and optical properties of the grown structures are investigated. The formation of relatively small Ge clusters at appropriate growth conditions is observed. Possible growth mechanism responsible for the formation of Ge nanostructures is discussed