Electroproduction of π from C leading to low-lying residual states in B

Energy distributions of π⁺ produced from ¹²C by electrons of total energy 195 MeV were measured at various angles. The results show large contributions from transitions leaving the residual nucleus in the ground (1⁺), first (2⁺) excited state and states at around 4.5 MeV. The angular distributions of ¹²C(γ, π⁺)¹²B leading to these residual states are deduced from the energy distributions by the unfolding method with the virtual photon theory. Theoretical results with the Helm model and the shell model are compared with the experimental results. Their relative shapes are in good agreement. A better agreement in the absolute value is found for the theoretical results which include the final-state interaction estimated with a pion optical potential. The surface production model shows better agreement with the experimental (γ, π⁺) cross sections than the volume production model.     

In-situ measurement of photochemical changes of solid samples by fourier transform infrared photoacoustic spectroscopy

Infrared spectral changes of lithographic printing plates were measuredin-situ by PAS and RAS. The advantages of PAS over RAS were discussed for the spectral measurements of organic coatings on roughened metal surface.     

Elasto-plastic bending of an annular plate at large deflection

Summary The elasto-plastic bending of a simply supported annular plate with a free inner edge upon which an uniformly distributed lateral load acts is theoretically investigated, taking into account the influence of the membrane forces. A homogeneous and isotropic elasto-perfectly-plastic material satisfying the Mises' yield condition and the Hencky's stess-strain relation is assumed. The theoretical results are discussed and compared with experimental results obtained with a plate of mild steel; the relation between the real behavior of the actual material and the usual assumptions used in the analysis is emphazised. The theoretical result is also compared with the result of an analysis in which the membrane forces were neglected; in this manner the influence of these forces is shown.

---

Übersicht Das elastisch-plastische Biegen einer einfach gelagerten Ringplatte wird theoretisch untersucht, wobei der Einfluß der Membrankräfte berücksichtigt wird. Der innere Rand der Platte ist frei gelagert und trägt eine stetig verteilte Querlast. Es wird ein homogenes, isotropes und ideal elastisch-plastisches Material vorausgesetzt, das der v. Misesschen Fließbedingung und dem Henkyschen Spannungs-Dehnungs-Gesetz genügt. Die Rechenergebnisse werden diskutiert und mit entsprechenden Versuchsergebnissen verglichen, wobei besonderen Wert auf die Beziehung zwischen dem wirklichen Materialverhalten und den üblicherweise in der Theorie verwendeten Annahmen gelegt wird. Die Ergebnisse werden außerdem mit entsprechenden Berechnungsergebnissen verglichen, bei denen die Membrankräfte vernachlässigt wurden, so daß der Einfluß dieser Kräfte deutlich wird.

     

Theoretische und experimentelle Untersuchungen an Tandem-Pumpengittern starker Umlenkung

Ohne ZusammenfassungGekürzte Fassung der von der Fakultät für Maschinenwesen der Technischen Hochschule Braunschweig genehmigten gleichnamigen Dissertation. Berichter: Prof. Dr. H. Schlichting; Mitberichter: Prof. Dr. H. Petermann. Die Untersuchungen wurden im Institut für Strömungsmechanik der Technischen Hochschule Braunschweig unter der Leitung von Prof. Dr. H. Schlichting durchgeführt und durch die Deutsche Forschungs-gemeinschaft und ein Stipendium des Verfassers vom Deutschen Akademischen Austauschdienst ermöglicht.Bei der Abfassung dieser gekürzten. Fassung hat Herr Dr.-Ing. K. Gersten mitgewirkt.     

Improvements in Carrier-to-Noise-Ratio (CNR) of Lightwave Amplitude Modulated Vestigial-Sideband (AM-VSB) Transmission Systems by the Use of Optical Isolators

In lightwave community antena television (CATV) systems as well as other optical fiber communication networks, a transmitted optical signal is known to be degraded by an intensity noise produced within the fiber due to the interference between the signal and doubly reflected light. We report on the improvements to the signal degradation due to the double Rayleigh backscattering by inserting optical isolators in the trunk lines of the systems. A carrier-to-noise ratio (CNR) has been calculated as a function of the number and the insertion loss of the isolators. The calculated results indicate that there is an optimum number of isolators, and if the insertion loss is less than 0.3 dB, the CNR degradation can be restored by more than 60%. To test the calculated results, we conducted experiments for the specific case of employing one isolator, and obtained good agreements between the two.