Uran-Prospektion in der Bundesrepublik Deutschland

Two deposits that can be considered economically minable have been found during the last twenty years of prospecting for uranium in the Federal Republic of Germany. These deposits, Menzenschwand and Müllenbach, are situated in the northern and southern Black Forest, respectively. In addition, favorable indications have been found in Paleozoic granites of northeastern Bavaria, of the Black Forest, and Odenwald, as well as in Permian and Triassic sediments of Rheinland-Palatinate, Franconia, and Württemberg. The uranium resources that can be expected from all these deposits are insufficient to meet the domestic demand.     

Non-aqueous electrolyte solutions

Non-aqueous electrolyte solutions are nowadays intensively studied owing to their unique properties for their application in various electrochemical devices and procedures. Important advances have already been made in high-energy primary batteries, wet capacitors, electroplating, phase-transfer catalysis and electro-organic synthesis; advances are expected in further fields such as high-energy secondary batteries, non-emissive displays, solar cells, thin-film procedures and coating. A survey is given both for successful recent applications and expectations.     

Report on International Affairs Committee

This is a report on Meetings of Representatives of National Air Pollution Preventions Associations to Consider the Establishment of an International Union, held in Washington, D. C, June 18–19, 1964 and Houston, Texas, June 21–22, 1964.     

Nitrogen fixation by cyanobacteria stimulates production in Baltic food webs

Filamentous, nitrogen-fixing cyanobacteria form extensive summer blooms in the Baltic Sea. Their ability to fix dissolved N₂ allows cyanobacteria to circumvent the general summer nitrogen limitation, while also generating a supply of novel bioavailable nitrogen for the food web. However, the fate of the nitrogen fixed by cyanobacteria remains unresolved, as does its importance for secondary production in the Baltic Sea. Here, we synthesize recent experimental and field studies providing strong empirical evidence that cyanobacterial nitrogen is efficiently assimilated and transferred in Baltic food webs via two major pathways: directly by grazing on fresh or decaying cyanobacteria and indirectly through the uptake by other phytoplankton and microbes of bioavailable nitrogen exuded from cyanobacterial cells. This information is an essential step toward guiding nutrient management to minimize noxious blooms without overly reducing secondary production, and ultimately most probably fish production in the Baltic Sea.     

Inorganic skeleton of the demosponge Halichondria panicea. Seasonality in spicule production in the Baltic Sea

Seasonality in spicule production of the demosponge Halichondria panicea (Pallas, 1766) was studied in the Western Baltic from July 1992 to July 1993. Spicule production increased in parallel with increasing temperatures in spring, being most pronounced during summer after release of larvae. Large proportions of up to 30% immature spicules occurred in the population during skeleton production peaks, and this resulted in reduction of mean spicule dimensions by ≃20%. Effects on spicule width were more obvious than on spicule length. In winter, when wave forces were largest, higher percentages of mineral skeleton were observed: 50% of dry weight compared to 40% in summer. Enhanced spicule densities in the tissues were not attained by marked spicule production but through a reduction in organic content by shrinking. In spring, growth of body tissue was faster than the build-up of skeleton, so that the relative amount of the latter was reduced. The indirect, growth-related developments of the skeleton were inversely proportional to temperature and directly to salinity, silicate concentrations and wave energy. Spicule size and the number of immature spicules were correlated with temperature and only slightly with salinity. No correlation with oxygen concentration or pH could be detected. Received: 3 April 1997 / Accepted: 8 August 1997     

Powerful data analysis routine helps locate buried bombs

Heavy bombing during World War II in Europe, particularly in Germany, left thousands of unexploded bombs buried underground and underwater. The bombs can be detected with magnetic sensors, but sorting through the huge amounts of data generated in area searches has proven to be by far the most difficult part of the task. Recently, a data analysis program has been developed that is capable of correlating global positioning system (GPS) data to magnetic sensor readings to identify likely bomb site candidates in a remarkably short period of time. A key to the success of this application is the use of packaged data-analysis software, Origin, from Microcal Software, Inc. (Northampton, Massachusetts), which is capable of interfacing to external C and C++ pattern curve-fitting routines that operate at the required high rates of speed.     

Silica uptake kinetics of Halichondria panicea in Kiel Bight

Besides diatoms Demospongiae are the most important consumers of dissolved silica in the sea. They can play an important role for the silica budget especially in the shallow water areas of the Baltic Sea. The dependence of the silica uptake rate on the silica concentration of the seawater was measured for the sponge Halichondria panicea (Pallas, 1766). The sponges were collected in Kiel Bight. The uptake conformed to Michaelis–Menten kinetics with a half-saturation constant of 46.41 μM and a saturated uptake rate of 19.33 μmol h⁻¹ g⁻¹ ( p < 0.01). In the red algae zone of Kiel Bight the sponges depend on silica supply from the surrounding waters and may be silica-limited rather than food-limited in growth. Because of the much faster uptake of silica by diatoms and their lower saturation point, as well as the difference in spatial distribution of the two main silica consumers, a competition for silica between sponges and diatoms seems unlikely. Received: 21 June 1997 / Accepted: 15 July 1997