Abstract: A heat exchanger is designed with variable heat transfer properties. The apparatus may include provisions for altering or varying the heat exchange characteristics of a heat exchanger by using one or more movable members that are connected to the inner surface of a heat exchange conduit to impede flow. The movable members may be positioned in a number of desired positions depending on the heat transfer rate needed.

Abstract: The present disclosure is directed to a process for plasma treating a film comprising titanium, nitrogen and impurities on a substrate. The process comprises forming a plasma of nitrogen gas and hydrogen gas, the flow ratio of hydrogen gas to nitrogen gas ranging from about 0.01 to about 0.7. The film is contacted with the plasma for a time sufficient to reduce the concentration of impurities in the film.

Abstract: Apparatus for pushing or pulling a pipe, rod or the like through subterranean areas, such as beneath sidewalks, roadways, etc. It is lowered into a pit and braced against opposing walls thereof by jacking out an extensible frame. Once positioned within the pit, a motor and pump unit supplies hydraulic fluid under pressure to a hydraulic cylinder which reciprocates through a lever arm a gripping means slidably mounted on the frame. When moved in one direction, the gripping means grips the pipe or rod while when moved in the other direction it disengages from the pipe or rod. The pipe or rod is thereby driven longitudinally into the ground. To pull the pipe or rod, the gripping direction of the gripping means is reversed by shifting the gripping member.