[en] A measurement of the dijet production cross section associated with a D^*± meson is presented. Deep-inelastic scattering (DIS) data collected by the H1 experiment at the electron-proton collider HERA, have been analyzed in a kinematical range defined by the DIS variables 2 ≤ Q² ≤ 100 GeV² and 0.05 ≤ y ≤ 0.7. In this kinematic range the cross section for the production of D^*± mesons in the visible range defined by the transverse momentum and the pseudorapidity of the D^*± meson 1.5 ≤ pt ≤ 15 GeV and vertical stroke η vertical stroke ≤ 1.5 is found to be 7.12 ± 0.21 (stat.) ± 0.98 (syst.) nb. The cross section for the production of dijets associated with a D^*± meson with a minimal transverse energy of the leading jets in the Breit frame of E_t,jet1^Breit > 4 GeV and E_t,jet2^Breit > 3 GeV and pseudorapidity in the laboratory frame -1 < η_jet1,2^lab < 2.5 is found to be 1.64 ± 0.12 (stat.) ± 0.24 (syst.) nb. Furthermore, differential cross sections are measured in the observables E_t^max, Δη, x_γ^obs and x_g^obs. The measurements are compared with the predictions of NLO calculations based on the DGLAP model and of the CCFM model. (orig.)

[en] In this report, a description is given of a simulating calculation for immunoscintigrams of tumours. Under consideration of the individual parameters registered, this calculation was to permit the following to be determined: minimum counting rate required for the detection of a lesion, the site and activity concentration of which was known; lower limits of detection on the basis of tumour size or minimum concentration of activity to be achieved in a lesion of predetermined extensions. Furthermore, radionuclide-related evaluations could be made of the quality of the scintigraphic images obtained. The method further permitted evaluations of the extent, to which the detection of a lesion is dependent on its site. Measures preceding the simulating calculation included the determination of image functions for J-133, Tc-99m and In-111, the preparation of homogenous scintigrams with deviating counting rates as well as the construction of a phantom of the abdomen. The results obtained basically lead to the following two conclusions: The value of immunoscintigraphic tumour detection is not only determined by that proportion of radioactivity accumulating at the surfaces of tumours cells but largely also by the properties of the tracers used. Even minute lesions may be detected, provided that the accumulated amount of radioactivity is adequate. If the accumulation behaviour of tracers can be improved in the future, immunoscintigraphy will certainly prove its value in the follow-up and early diagnosis of metastising tumours. (orig./MG)

[en] This article discusses the controversy concerning the safety of irradiated foods. Critics claim that irradiated food may contain unhealthful chemicals and have lower levels of some nutrients. Other researchers have shown the helpful reduction of bacteria in irradiated foods thereby lowering the incidence of foodborne illness

[en] Stellar ²²Na(p,γ)²³Mg reaction rates at temperatures below 10⁹ K have been determined by investigation of the ²²Na(³He,d)²³Mg proton transfer reaction at a ³He energy of 30 MeV. A radioactive ²²Na target (T 1/2 = 2.6 y) was provided by implantation of ²²Na into a 75 μg/cm² carbon foil. Deuteron groups from the (³He,d) reaction corresponding to ²³Mg states near the proton threshold were observed at angles between 7.5 degrees and 31 degrees in order to determine proton single particle widths. The results led to a considerable reduction of the uncertainties in the low temperature ²²Na(p,γ)²³Mg reaction rates

[en] Models of QCD must confront nonperturbative phenomena such as confinement, dynamical chiral symmetry breaking (DCSB) and the formation of bound states. In addition, a unified approach should describe the deconfinement and chiral symmetry restoring phase transition exhibited by strongly-interacting matter under extreme conditions of temperature and density. Nonperturbative Dyson-Schwinger equation (DSE) models provide insight into a wide range of zero temperature hadronic phenomena; e.g., non-hadronic electroweak interactions of light- and heavy-mesons, and diverse meson-meson and meson-nucleon form factors. This is the foundation for their application at nonzero-(T, μ). Herein the authors describe the calculation of the reconfinement and chiral symmetry restoring phase boundary, and the medium dependence of ρ-meson properties. They also introduce an extension to describe the time-evolution in the plasma of the quark's scalar and vector self energies based on a Vlasov equation

[en] Government of Slovak Republic advanced on 21 April 1999 important document for nuclear power plant Bohunice locality - 'Report about the state of nuclear power plant V-1 Bohunice reconstruction and reasoning its further operation'. The article refers to abolition of government decision to shut-down nuclear power plant V-1

No abstract available

[en] The article by the Bohunice NPP General Manager describes the history of the Slovak nuclear power sector and gives basic information regarding the orientation and development of nuclear power in Slovakia. The milestones in the history of the Bohunice nuclear power plant site are highlighted, and the main attributes of each NPP operator, i.e. safe and reliable operation and a safety upgrading programme, are characterized as a continuous process which is launched the first day of plant operation

[en] Spectral element methods have previously been successfully applied to direct numerical simulation of turbulent flows with moderate geometrical complexity and low to moderate Reynolds numbers. A natural extension of application is to large eddy simulation of turbulent flows, although there has been little published work in this area. One of the obstacles to such application is the ability to deal successfully with turbulence modelling in the presence of solid walls in arbitrary locations. An appropriate tool with which to tackle the problem is dynamic estimation of turbulence model parameters, but while this has been successfully applied to simulation of turbulent wall-bounded flows, typically in the context of spectral and finite volume methods, there have been no published applications with spectral element methods. Here, we describe approaches based on element-level spectral filtering, couple these with the dynamic procedure, and apply the techniques to large eddy simulation of a prototype wall-bounded turbulent flow, the plane channel, using a mixing length-based eddy viscosity subgrid-scale model. The methods outlined here may be carried over without modification to more complex geometries

[en] Distribution of ²²⁶Ra activities and ²²⁸Ra/²²⁶Ra activity ratios were measured in the surface waters of the Irish Sea and in the English Channel. ²²⁶Ra activities vary from 0.001 Bq.1^-1 for the Atlantic water to 0.002 Bq.1^-1 for coastal waters, whereas ²²⁸Ra/²²⁶Ra activity ratios increase from 0.18 to 2.18. The coastal waters are clearly dominated by radium injection from nearshore sediments. (author)