Hard gamma as probe of nuclear dynamics

Experimental results concerning the ⁵⁸Ni + ⁵⁸Ni at 30 MeV/u and ⁵⁸Ni + ¹⁹⁷Au at 30 and 45 MeV/u reactions are presented. The emission mechanism of hard photons has been exploited to get information on the time evolution of the reactions. From the measured hard gamma multiplicity associated to different classes of heavy residues a quantitative estimate of the reaction centrality has been obtained. Moreover, evidence of a prompt Intermediate Mass Fragment (IMF) emission is shown for the Ni + Au reaction at 45 MeV/u for central collisions exploring the correlation function between thermal photons and IMF’s.     

Comparative Investigations on the Reproducibility of the Hollow Cathode,Glow Discharge and Spark Light Sources

A comparison between the constancy and reproducibility of the hollow cathode, glow discharge and spark light sources was carried out. Samples of pure copper as well as of commercial brass and steel were investigated. Results show that the hollow cathode produces a better reproducibility of the measurements in all the cases examined.     

Equitable Specialized Block-Colourings for Steiner Triple Systems

We continue the study of specialized block-colourings of Steiner triple systems initiated in [2] in which the triples through any element are coloured according to a given partition π of the replication number. Such colourings are equitable if π is an equitable partition (i.e., the difference between any two parts of π is at most one). Our main results deal with colourings according to equitable partitions into two, and three parts, respectively.     

II. Kritische Gegenüberstellung photographischer und photoelektrischer Apparate und Methoden der Absorptionsspektroskopie

Zusammenfassung Apparate und Methoden, die auf photoelektrischem bzw. auf photographischem Wege arbeiten, werden bezüglich des Endergebnisses der am häufigsten vorkommenden absorptionsspektroskopischen Messungen (Analyse und Strukturuntersuchungen) miteinander verglichen. Nach einem kurzen Hinweis auf die Fehler, die im Endergebnis größenordnungsmäßig zu erwarten sind, werden einige Richtlinien für die Wahl des zweckmäßigsten Apparates diskutiert.

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Summary A comparison is given of the apparatus and methods, which function photoelectrically or photographically, with respect to the end results of the most common absorption spectroscopic measurements (analysis and studies of structure). After a short reference to the errors, which may be expected in the final result, with respect to their order of magnitude, a discussion is given concerning several suggestions as to the choice of the most suitable apparatus.

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Résumé On compare appareils et méthodes qui fonctionnent suivant un procédé photoélectrique ou photographique, avec les résultats finaux des mesures d'absorption spectroscopiques les plus habituelles (analyses et études de structure). Après un examen des erreurs que l'on peut attendre dans le résultat final et de leur ordre de grandeur, on discute diverses suggestions concernant le choix de l'appareil le plus convenable.