Showing papers by "Swiss Federal Institute of Aquatic Science and Technology published in 1972"
01 Mar 1972
TL;DR: In this article, the authors discuss die Eutrophierung unserer Gewasser sind vor allem Phosphor und Stickstoff von Bedeutung.
Abstract: Fur die Eutrophierung unserer Gewasser sind vor allem Phosphor und Stickstoff von Bedeutung. Diese beiden Elemente sind in der Landwirtschaft in grossen Mengen im Umlauf: Dungemittel, flussige und feste Abfalle aus der Tierhaltung, Abfluss aus Silos usw.
35 citations
01 Sep 1972
TL;DR: The daily primary production in lake Lucerne (47° n latitude) was determined at different depths at approximately monthly intervals between 22 July 1969 and 8 May 1970, by summing up series of short term measurements made during each day, using the C14 method as discussed by the authors.
Abstract: The daily primary production in lake Lucerne (47° n latitude) was determined at different depths at approximately monthly intervals between 22 July 1969 and 8 May 1970, by summing up series of short term measurements made during each day, using the C14 method. Simultaneously irradiant energy and attenuation of light in the water was measured. It is shown that, considering the photosynthesis-light response the trophogenic layer of the lake can be assumed as homogeneous only from mid October to the end of March. Different known models to estimate daily surface production rates are compared with direct measurements and a new numerical model is described which allows daily production as a function of depth to be calculated. A method is presented which converts the production rate per unit of surface area measured during a standard exposure time to the daily production rate.
29 citations
01 Sep 1972
TL;DR: In this article, it is shown that it is possible to achieve perfect linearity with the aid of a modern operation amplifier, owing to the extremely low impedance of the photo element input.
Abstract: There are several alternative methods for the in situ measurement of light in water. Of the available methods the selenium photo element has been most widely used, largely because of its operational simplicity. The inherent deficiency of this technique, its nonlinear reading, could not be alleviated with the technology available at the time of the method's introduction. It is now possible to achieve perfect linearity with the aid of a modern operation amplifier, owing to the extremely low impedance of the photoelement input. The design of the apparatus is described in detail.