Die Entfernung von Cadmiumionen aus Spülwässern der galvanischen Industrie mittels Ionenaustausch

In laboratory investigations with model waters, the behaviour of selected cation-exchange resins (Amberlite 200 C, Duolite C-25, Lewatit S-100, Wofatit KPS and Wofatit KS-10) is tested. The usable volume capacity of the resins in the forms of H, Na and NH₄ as well as the water content and the total volume capacity after 25 cycles of loading/regeneration are determined. It is recommended to use Amberlite 200 C and Wofatit KS-10.     

River Warren boulders, Minnesota, USA: catastrophic paleoflow indicators in the southern spillway of glacial Lake Agassiz

Boulders resting on meltwater-sculpted and striated-granite bedrock near the head of the southern outlet spillway of glacial Lake Agassiz are used to generate paleodischarge calculations. The rounded nature of many boulders suggests fluvial transport and a corestone origin. The distribution of boulders in clusters and linear trains records the interaction of clasts during transport and deposition. The geomorphology of the spillway with streamlined erosional remnant hills is characteristic of other large flood spillways. Using the Manning equation and a variety of empirical equations to determine paleovelocity, preferred discharges between 0.364 and 0.102 Sv are calculated. These discharges agree well with flood discharges using modeling methodologies, and most likely represent ephemeral and catastrophic flood events linked to either episodic incision at the outlet or the result of rapid inputs of meltwater to Lake Agassiz.     

Low-frequency electric field fluctuations excited by ring current protons

Energetic protons haying ring type distributions are shown to generate low-frequency electrostatic waves, propagating nearly transverse to the geomagnetic field lines, in the ring current region by exciting Mode 1 arid Mode 2 nonresonant instabilities and a resonant instability. Mode 1 nonresonant instability has frequencies around ~4 Hz with transverse wavelengths of ~(8–80) km, and it is likely to occur in the region L = (7–8). Mode 2 nonresonant instability can generate frequencies ~(850–1450) Hz with transverse wavelengths ~(2–20) km. The typical frequencies and transverse wavelengths associated with the resonant instability are (950–1250) Hz and (30–65) km. Both the Mode 2 nonresonant instability and the resonant instability can occur in the ring current region with L = (4–6). The low-frequency modes driven by energetic protons could attain maximum saturation electric field amplitude varying from 0.8 mV/m to 70 mV/m. It is suggested that the turbulence produced by the low-frequency modes may cause pitch angle scattering of ring current protons in the region outside the plasmapause resulting in the ring current decay.     

A technique for calibration of monostatic echosounder systems

A calibration technique has been adapted to render complete system calibrations of high-frequency acoustical instrumentation. This is based on standard targets; specifically, precisely manufactured spheres composed of tungsten carbide with 6% cobalt binder. The use of multiple sphere sizes was found to be advantageous, both as an independent check of the calibrations, and so that resonances in the sphere responses at certain frequencies could be avoided. Complete system gains and beam patterns, which include effects of bandpass filters and finite-pulse lengths, were determined by moving the spheres individually in the transducer far-fields. Use of this procedure ensures control over the acoustical characteristics of transducers, which may change from the time of manufacture and first testing due, for example, to platform mounting. It also provides a direct means of measuring the sampling volume at relatively high and constant signal-to-noise ratios. Implementation of this technique is discussed using a multifrequency sonar system as an example