[en] Plasma generation and plasma state values are discussed along with the measurement of line width and line shift which are caused by the Stark effect of the microfields of a plasma and play an important part in plasma diagnostics. An apparatus for measuring these values as a factor of the electron density was developed, and investigations were carried out with Ar, Kr, and Xe. (HK/AK)

[en] In the present thesis deviations from model predictions, which had been resulted in earlier studies at heavy ion reactions at inceident energies at the Coulomb barrier, should be further studied. For this the reaction ⁵¹V+¹⁹⁷Au was studied exactly on the barrier and at an incident energy increased by 25 MeV. The reaction products were captured in a copper foil, in a comprehensive chemical separation procedure separated, and γ-spectroscopically studied. From the γ decay rates cross sections for about 270 isotopes of the elements potassium to polonium were determined

[en] The mini-camera detects at least a nuclear radiation β and γ (or related) emitted by a radioisotope contained in a body. Its shot head includes a collimator, a scintillator and a photo detection group. According to the invention, the shot head is also equipped with hole modulation grid placed between the collimator and the scintillator. Under the action of an appropriate mechanism the grid can open, or shut, completely the collimator. The signals of the photo detection group collected in opening position (respectively closing) are supplied to a first (respectively second) image memory. Comparison and calculation means provide by simple subtraction the useful signal sought from the two memories content. Ablation aid of cancerous tissues application. 8 refs., 4 figs

[en] Surveys and opinion polls regularly reinforce the belief that nuclear waste is one of the general public greatest fears. Their results reflect the way this theme is handled by the media, often in a negative or controversial light. Closer examination of these surveys, however, reveals that the apparently delicate situation of nuclear waste in public opinion deserves a more subtle, qualified approach. (author)

[en] In a diaphragm shock-tube, Ar, Kr and Xe plasmas were generated with equilibrium temperatures of 8,000 to 12,000 K. The electron densities were measured with a two-wavelength interferometer and varied from 4 x 10¹⁶ to 1.4 x 10¹⁷ cm^-3. Emission profiles of spectral lines were recorded with a polychromator setup in 1 μs intervals using a fast data acquisition system. Width w and shift d turned out to be proportional to electron density Nsub(e) for the observed lines. Stark broadening parameters w/Nsub(e) and d/Nsub(e) are presented for 3 Ar(I), 4 Kr(I) and 5 Xe(I) lines in the visible region of the spectrum. (author)

[en] The absolute transition probability for the KrI line 5871 A was measured by applying Rozhdestvenskii's hook method and a related interferometric method to shock wave plasmas. The result Asub(ik)=2.2 X 10⁶ s^-1 is compared with theoretical and other experimental data. (Auth.)

[en] This review is concerned with the characterization and identification of the deep centres that cause current collapse in nitride-based field effect transistors. Photoionization spectroscopy is an optical technique that has been developed to probe the characteristics of these defects. Measured spectral dependences provide information on trap depth, lattice coupling and on the location of the defects in the device structure. The spectrum of an individual trap may also be regarded as a 'fingerprint' of the defect, allowing the trap to be followed in response to the variation of external parameters. The basis for these measurements is derived through a modelling procedure that accounts quantitatively for the light-induced drain current increase in the collapsed device. Applying the model to fit the measured variation of drain current increase with light illumination provides an estimate of the concentrations and photoionization cross-sections of the deep defects. The results of photoionization studies of GaN metal-semiconductor field effect transistors and AlGaN/GaN high electron mobility transistors (HEMTs) grown by metal-organic chemical vapour deposition (MOCVD) are presented and the conclusions regarding the nature of the deep traps responsible are discussed. Finally, recent photoionization studies of current collapse induced by short-term (several hours) bias stress in AlGaN/GaN HEMTs are described and analysed for devices grown by both MOCVD and molecular beam epitaxy. (topical review)

[en] Simulation of generalized fracture and fragmentation remains an ongoing challenge in computational fracture mechanics. There are difficulties associated not only with the formulation of physically-based models of material failure, but also with the numerical methods required to treat geometries that change in time. The issue of fracture criteria is addressed in this work through a cohesive view of material, meaning that a finite material strength and work to fracture are included in the material description. In this study, we present both surface and bulk cohesive formulations for modeling brittle fracture, detailing the derivation of the formulations, fitting relations, and providing a critical assessment of their capabilities in numerical simulations of fracture. Due to their inherent adaptivity and robustness under severe deformation, meshfree methods are especially well-suited to modeling fracture behavior. We describe the application of meshfree methods to both bulk and surface approaches to cohesive modeling. We present numerical examples highlighting the capabilities and shortcomings of the methods in order to identify which approaches are best-suited to modeling different types of fracture phenomena

[en] In 2009 the Ministerial Council Meeting of the Organisation for Economic Co-operation and Development (OECD) committed itself to a green growth strategy. Such a strategy fosters economic growth and development while ensuring that natural resources can continue to provide the ecosystem services on which our well-being relies. It also endorses investment, competition and innovation which will underpin sustained growth and give rise to new economic opportunities. Green growth provides both a policy strategy for implementing this economic transformation and a monitoring framework with a proposed set of indicators. This report presents an overview of the state of green growth in the Netherlands. It should be regarded as a benchmark for a more thorough and comprehensive assessment of green growth in the future. It is based on the set of indicators proposed by the OECD in their intermediate report of February 2011. Data relevant to the Dutch situation are presented for twenty of these indicators, illustrating the observed trends. The indicators are grouped in four themes. For the first theme, environmental efficiency of production, on the whole the indicators show increased efficiency. However, indicators such as greenhouse gas intensity, energy efficiency and material intensity show only relative decoupling, which on its own is not enough to ensure green growth. In addition, the increase in environmental efficiency is partly explained by substitution of imports for domestic production, which is not conducive to green growth on a global scale: the efficiency gains in domestic production, for example, are offset by increases in foreign greenhouse gas emissions. Water use and agricultural nutrient surpluses are the only indicators where absolute decoupling has occurred. The second theme contains indicators regarding the natural assets base. This group of indicators provides a mixed picture. Natural gas reserves are decreasing and the overall level of threat to animal species has increased. On the other hand, forests (standing timber) have increased. For the third theme, environmental quality of life, more indicators need to be developed. The only available indicator is the one on pollution induced health problems, which shows a slightly positive trend. The number of green patents, green jobs, and the share of green taxes are all increasing. We note, however, that it is difficult to interpret the relevance of these indicators on policy responses and economic opportunities in relation to green growth, which constitute the fourth theme of our report.

[en] Atomistic simulation is used to examine nanoindentation of a Au(111) crystal both near and far from a surface step. While the load needed to nucleate dislocations decreases significantly when indenting close to the step, the extent of the step's influence is not as great as seen experimentally. This behavior is explained by measuring the contact area from the simulation data. A new metric, the slip vector, shows material slip coinciding with the <112> directions of a lowest unstable stacking fault barrier. The slip vector is used to calculate an atomic critical resolved shear stress, which is shown to be a good dislocation nucleation criterion