Modifications to the method of moments

A modification to the standard moment procedure is proposed for thin-wire aerials of arbitrary shape. Using a homogeneous form and 2nd-order approximations, a normalised current can be obtained, from which the impedance is calculated by integration of the near fields.     

Prinzip-Analyse von zwei Röntgen-Verformungsmeßverfahren

Erläuterung der Methoden zur Ermittlung mechanischer Spannungen unter besonderer Berücksichtigung der räumlichen Verhältnisse bei der Röntgenmessung. Darstellung der Verformungsgeometrie und der daraus abgeleiteten Meßverfahren. Vergleichende Gegenüberstellung des Röntgen-φ-Integralverfahrens mit dem Röntgen-ψ-Integralverfahren.     

The expected linearity of a simple equivalence algorithm

The average time needed to form unions of disjoint equivalence classes, using an algorithm suggested by Aho, Hopcroft, and Ullman, is shown to be linear in the total number of elements, thereby establishing a conjecture of Yao. The analytic methods used to prove this result are of interest in themselves, as they are based on extensions of Stepanov's approach to the study of random graphs. Several refinements of Yao's analyses of related algorithms are also presented.     

Interfade Interval Statistics of a Rayleigh-Distributed Wave

This paper presents distributions of the intervals between fades measured on a hardware-simulated Rayleigh-fading mobile radio channel. For intervals between deep fades, these distributions take on a Poisson form. Measured results are in good agreement with a simple analytical model. Distributions for the intervals between shallower fades exhibit preferred durations caused by peaks in the Doppler fading spectrum.     

Trends in use and prospects for the future harvest of world fisheries resources

Estimates of the potential yield from the marine environment have varied between 20–1000 million metric tons because they were based on poor and incomplete data and differing approaches to trophic level evaluation. The data is improving slightly and the estimates are beginning to agree within half an order of magnitude. We believe that the yield of marine fisheries could ultimately be expanded to ca. 400 million metric tons, by utilizing presently known but underutilized resources, by opening new fisheries in areas like the Indian Ocean and Antarctic and by improving systems of regulating the catch and fishing effort. In order to meet the maximum potential of the marine environment we will have to harvest at a lower trophic level in the food chain because most fish in higher trophic levels are being harvested at their maximum sustainable yield. This increasing harvest of smaller fish, plus the increasing demand for fishmeal for animal feed will cause an increasing proportion of the fish harvested to be used for reduction to fishmeal and oil. One of 11 papers presented in the symposium “World Supply of Edible Oils and Proteins,” Atlantic City, October 1971.     

Energieeinsparung in der Verfahrenstechnik

Energy saving in process engineering . As is already well known, the overriding factor in thermal processes in the chemical industry is the cost of energy. Because of the considerable rise of prices for primary energy all over the world, efforts have been started to decrease the specific energy consumption for chemical products. In the first part of this paper possible ways of saving energy in the chemical industry are considered from a theoretical point of view. A principle motive was to decrease the percentage of primary energy needed in a process. In particular, the thermodynamic examination of heat pumps, multi-stage processes and the possible integration of backpressure engines in a chemical complex are treated. In the second part some planned and practically executed examples are shown with actual indications of energy savings. Hereby, the relatively greater increase of primary energy costs versus in vestment costs in recent years have been considered.     

Zur konvektiven Wärmeübertragung an Außenflächen von Industrieöfen

Untersuchung der konvektiven Wärmeübertragung an waagerechten und senkrechten Flächen. Vergleich der Ergebnisse mit Schrifttumsangaben. Versuche über den gegenseitigen Einfluβ waagerechter und senkrechter Flächen aufeinander bei konvektiver Wärmeübertragung an einem idealisierten Ofen (oberflächenbeheizter Würfel). Entwicklung einer Gebrauchsformel für die konvektive Wärmeübertragung an Auβenflächen von Industrieöfen.