Abstract: The invention relates to an apparatus for generating heterodyned seismic signals as well as methods of using the heterodyned signals and a system for generating the heterodyned seismic signals. The heterodyned signals can be used near sensitive marine animals because the source frequencies are ultrasonic and the heterodyned seismic signal is generated in a narrow beam.

Abstract: Lignite is treated with ligninase source to enhance its reactivity. In one embodiment, lignite is gasified in a subterranean reactor by simultaneous digestion by anaerobic ligninase producers, such as termite microflora, and acid formers and methanogens. In another embodiment, the lignite is treated with ligninase prior to digestion by the acid formers and methanogens. If desired, the lignite may be pretreated by alkaline hydrolysis.

Abstract: Coal is desulfurized by oxidation to convert organic sulfur moieties in the coal matrix to sulfates, and by treatment with a sulfatase to cleave the sulfates and thereby remove organic sulfur.

Abstract: A ballast circuit for a discharge tube such as a fluorescent tube, mercury vapor, sodium vapor or metal halide lamp is disclosed. D.C. power is provided alternately between two output driver stages and an a.c. neutral return line. In output transformerless (OTL) embodiments of the invention, a series connection of a reactance circuit and the tube is connected between the push pull point and the a.c. neutral return line. In transformer embodiments of the invention, a primary winding of a transformer is connected in series with the reactance circuit. The tube or load is connected across an output winding of the transformer with the electrical effect that the load is in series with the reactance circuit. Alternative arrangements of transformer input windings are provided. The first includes two input primary windings wound in opposite directions with the circuit arranged such that current flows in one or the other of the input transformer windings on alternating half cycles of the control signal.

Abstract: A method for carrying out a biochemical reaction with a culture of microorganisms is performed in a cavity formed in a subterranean formation to produce combustible hydrocarbon gases. The method is especially suitable for the conversion of alkali-oxidized or hydrolyzed coal, such as lignite, to methane. The method may be performed in the cavity as a continuously stirred tank reaction, or plug flow or as a staged reaction. The method may also be done as an anaerobic fixed film process using particles as an anaerobic filter, as a sludge blanket, or as an expanded bed process.

Abstract: A method for carrying out biochemical reaction is disclosed. The method includes placing a suitable substrate in a cavity formed in a subterranean formation, inoculating the substrate with a culture of microorganisms, maintaining conditions suitable for the growth of the microorganisms, allowing the microorganisms to grow in the substrate in the cavity, and recovering a biochemical product formed thereby. The method is especially suitable for the conversion of alkali-oxidized or hydrolyzed coal, such as lignite, to methane.

Abstract: A steam supply system is provided for use in conjunction with both a superposed turbine driven by a steam boiler and a process chamber. The steam boiler operates at a pressure above that needed for consumption in the process chamber and uses highly purified water. The process chamber can use steam which has been generated from relatively low purity water and may be any steam consuming process, such as in one embodiment coal gasification, not requiring that the water be returned for re-use as steam. Energy remaining in the high purity steam after it leaves the superposed turbine is used in a condensing reboiler to heat the water into steam for the process chamber. The two fluids are kept essentially isolated from contact with each other in the condensing reboiler, and the high purity water is pumped back to the high pressure boiler in a closed loop system.