Radio observations of filaments during the eclipses of September 11, 1969 and March 7, 1970

By high resolution observations at 3 mm wavelength during the eclipses of September 11, 1969 and March 7, 1970 we have observed two filaments on the solar disc in absorption. We analyze in detail the 3.3 mm eclipse data and 9.5 mm (non-eclipse) data we have pertaining to the large filament observed on September 11, 1969. At 3.3 mm the plasma temperature in the filament is about 3900K, and at 9.5 mm it is about 6400K, indicating a multicomponent model. An upper bound of N _e ² L < 10²⁸ for the emission measure of a hot component at T > 10⁴K is obtained.     

A New System for Ground Water Monitoring

This paper describes a new system for ground water monitoring, "the BAT System," which includes the following functions: (a) sampling of ground water in most types of soils, (b) measurement of pore water pressure, and (c) in situ measurement of hydraulic conductivity. The system can also be used for tracer tests. The system utilizes a permanently installed filter tip attached to a steel or PVC pipe. Installation is normally performed by pushing the tip down to the desired depth. The filter tip can also be buried beneath a landfill. The primary feature of the new system is that the filter tip contains a self-sealing quick coupling unit, which makes it possible to temporarily connect the filter tip to adapters for various functions, e.g. water sampling and for measurement of pore pressure and hydraulic conductivity. The new technique makes sampling of both pressurized water and gas possible. Samples are obtained directly in hermetically sealed, pre-sterilized sample cylinders. Sampling of ground water and measurement of pore pressure can be repeated over a long period of time with undiminished accuracy. This technique is also well-adapted for taking water samples from different strata in a soil profile, in both the saturated and unsaturated zones. Actual installations range from 0.5 to 60m depth.