[en] The present work is based on neutrino experiment data with the Gargamelle bubble chamber in the broad band beam of the CERN protonsynchrotron. For the first time the reaction νn → νn π⁰ was separated from the π⁰-production at the proton. Besides, the reactions ν¹H → μ^-pπ⁺ could be separated at the free proton by means of kinematic techniques. However, about 80% of all reactions take place at the bound nucleons and this way the observed final state can be falsified by intranuclear secondary interactions. A correction of this falsification was made by means of a model calculation. By using recent nuclear physics data the model parameter could be calibrated and the correctness of the model calculation could be proved in all details. As a result the cross sections for the 1π-production could be given for free nucleons. The behaviour of these cross-sections was investigated in dependence of the invariant mass of the hadronic final state to find some clues of the isospinstructure of the weak currents. (orig./HSI)

No abstract available

[en] The proceedings contain 49 lectures which were held in the four technical sessions of the conference in Leoben. The contributions mainly deal with the influence of the structure on the fracture toughness and with the influence of fatigue, temperature and environment on the fracture behavior of specific materials. Although the metal materials still are the main topic, there also are contributions on the fracture behavior of ceramics and polymer or composite materials. (MM)

[en] I report on recent results obtained by experiments at the e⁺e^- storage ring PETRA. Data collected at c.m.s. energies between 30 and 46.2 GeV are analyzed to single out e⁺e^- → cc^- (bb^-) tagged by the semileptonic decay of the quarks into muons. The transverse momenta of these muons with respect to the quark direction as well as the event shape allow for an efficient separation of the sample into its b and c contents and thus for a measurement of the c and b semileptonic branching ratios. The longitudinal momentum spectrum gives information about their fragmentation properties. Charm quark identification is also obtained by observing high momentum D mesons among its fragmentation products. Both methods allow for a measurement of the forward-backward charge asymmetry in b and c production, found to be in agreement with the usual assignment of weak isospin for these quarks and thus indicating that the b quark is member of a doublet

[en] Ion etching has proved advantages over conventional metallographic microstructure investigations if special problems have to be solved. The different modes of operation of ion etching processes (inert/reactive sputtering) offer a lot of possibilities because it facilitates the variation of the diverse parameters. Ion etching can be applied in metallography, for example in the surface purification by the removal of layers, in the structure development of non-conductors and heterogeneous material combinations, as well as in the investigation of volume damages, like cracks, pores and cavities. It might be desirable for metallography laboratories to have a simple ion etching device at their disposal. (orig.)

[en] A new approach to sampling and measuring the unattached fraction of radon decay products is presented. Two methods of electrostatic sampling with polystyrene plates charged by friction or with copper plates connected to a high voltage source are compared to conventional sampling on wire mesh screens. A good correlation between Po-218 alpha activities for the three sampling methods for different radon concentrations and aerosol conditions was found. For total beta activities correlation between the methods is less obvious. (author)

[en] The author reports experience gained in migrating sequential High Energy Physics code to loosely and tightly coupled parallel processing systems. Constraints coming from the systems' hardware, the structure of the code and the available system's software are discussed. The parallel test implementations developed for the IBM/FPS Loosely Coupled Array of Processors and the ELXSI 6400 Multiprocessor are described. A minimum functionality for a set of loosely coupled Emulating Processors is established. (Auth.)

[en] Selected results from LEP on electroweak neutral currents and strong interactions are reviewed. In the first part, total cross sections, angular and polarization symmetries are interpreted in terms of basic electroweak parameters, like the mass, total and partial widths of the Z and neutral current couplings. Special attention is given to two apparent problems: the discrepancy between the measurements with final state vs. initial state polarization; and the deviation of the measured width of the Z into heavy quarks from Standard Model expectations. These discrepancies are not very significant, but they are the only ones observed at this point and thus deserve attention. In the second part, I outline results on final state strong interactions, namely measurements pertaining to differences between quark and gluon jets and the QCD group structure. (author) 19 figs., 4 tabs., 21 refs

[en] Selected results from L3 on the production and decay of heavy flavors are presented. The coupling of the weak neutral current to b quarks and τ leptons is measured in the total cross section and the angular asymmetry of their production at the Z⁰ resonance. For b quarks, the additional complication through B⁰-B-bar⁰ mixing needs to be taken into account. The coupling of b and τ to the weak charged current is studied looking at their decay properties, in particular their leptonic branching fractions and lifetimes. As far as the search for new particles is concerned, the discussion is limited to results on the production of Higgs particles as predicted by the Standard Theory. (author)

[en] Selected results on decay properties of the τ lepton are reviewed. Special emphasis is given to two puzzles in the understanding of τ decays at the present level of experimental accuracy: the problem of consistency between τ and μ lifetime given the small electronic branching ratio of the τ; and the problem of establishing that indeed all important τ decay channels have been observed. New and partially preliminary data from ALEPH, DELPHI, 1.3 and OPAL confirm a long lifetime and small electronic branching fraction of the τ. New measurements of inclusive, semi-inclusive and exclusive branching fractions fail to resolve the completeness controversy. (author) 16 refs.; 6 figs.; 3 tabs