[en] The author presents tables of medium-usage solar collectors in connection with their characteristic values: optical efficiency during perpendicular light leak, and thermal loss factor for small differences between operating and external temperatures. With the aid of these data, each prospective buyer can quickly and easily determine the monthly gross heat yield for various collector types. (A.N.K.)

[en] For the computation of the gross heat output of solar collectors by means of meteo data and characteristic collector parameters two programs were developed: MURD for the determination of the ''mean usable radiation density'' and ETA for the calculation of the collector efficiency i.e. relative values of gross heat output. The main features of these programs are described and detailed instructions for the use of them are given. Results of some cases for the meteo-situation of Zurich airport are given. (Auth.)

No abstract available

[en] The authors present the results of a test programme of solar collectors performed during the summer of 1978. (G.T.H.)

No abstract available

[en] The results of the EIR collector test series of the summers 1978 and 1979 are presented. In total, there are 37 different collectors available on the Swiss market. The results are compared with those from the IEA (International Energy Agency) of presuggested reference collectors. Test methods are described and also the construction of the test bench. Also, briefly described is a development method for the calculation of gross heat yield from solar collectors. Then the characteristics of the reference collectors in connection with the test periods are considered, and their role in the calculation of results of single collector test series explained. A description of the spectral photometer is given. (A.N.K.)

[en] Classical, time-independent solutions of the Yang-Mills equations are studied for spherically symmetric situations. In presence of charge- and current distributions the same types of solutions are found as for purely electric sources: besides the abelian (Coulomb-Biot-Savart) solution there are two nonabelian types, one of which requires minimal source strengths and comes in two branches. The solution pattern is investigated by rough numerical calculations for a simple source model corresponding to spherical shell distributions. In absence of charge distributions an additional type is found, which has zero electric field and a magnetic field corresponding to a monopole of fixed strength. This type of solution exists for a large class of reasonable source currents. Some analytical examples are given in addition to numerical results for the shell model. Stability problems are not touched. (Auth.)

[en] Comments are presented on some investigations in connection with the analysis of many-particle final states in hadron collision processes. The UNCM (Uncorrelated Neutral Cluster Model) is used to describe the distribution of charge transfer. Several distributions are studied in the presence of rapidity gap G to obtain additional insight into the UNCM structure. It was not possible to get new information on the underlying two-step structure of cluster formation and subsequent decay but connection is observed with the general principle of the local compensation of a charge in the rapidity space. Briefly discussed are also the distribution of y-interval widths in the particles produced and the zone lengths. (Z.J.)

[en] The accumulating evidence for clustering of produced particles in inelastic hadron scattering is reviewed, and described in terms of a two-step mechanism of production and decay of clusters. First hints for this phenomenon came from the investigation of multiplicity distributions, but the real need for clusters arose in order to account for inclusive two-body correlations. After a review of these facts, the connection between inclusive and semi-inclusive distributions is worked out in detail. The charge structure of clusters is then studied by consideration of charge transfer distributions in phase space. Finally an analogy between this concept of clusters and the idea of gluons and partons is mentioned. Although all these features are suggestive and the model describes the data reasonably well, it is still unclear whether real clusters exist or whether they are a mere practical parametrization of an unknown mechanism. (Auth.)

[en] Nonlinear U(N) and O(N) sigma-models are studied without imposing a constraint on the modulus of the field vector. Exact solutions in four-dimensional Minkowski space are presented, which have the form of plane resp. spherical waves. The singularities of the solutions as well as those of the Lagrangian density and the energy-momentum tensor are discussed. All results hold under the assumption, that space-time and internal symmetry of freedom are not mixed. (Auth.)