Abstract: Combustion is used as a source of heat to remove polluting volatiles from contaminated groundwater and subsurface soil. A burner assembly is placed in a well, either in or out of an aquifer, to produce steam and/or hot air and/or hot water which drives off the volatile contaminants which are collected through separate wells or vents depending upon the site. The combustion product gases are vented to atmosphere. Key elements are the addition of heat as close to the depth of the contaminated region as possible, transfer of heat through the aquifer and/or ground through the flow of steam and/or hot air and/or hot water to regions affected by the contaminants, and by drawing the flow to other well sites by which the contaminants are removed by pumping and subsequent treatment. Some of the contaminants are thermally destroyed.

Abstract: Combustion is used as a source of heat to remove polluting volatiles from contaminated groundwater and subsurface soil. The combustor is placed in a well, either in or out of an aquifer, to produce steam and combustion product gases and/or hot water which drives off the volatile contaminants which are collected through separate wells or vents depending upon the site. Key elements are the addition of heat in-situ by causing the combustion to occur below the ground or water level, transfer of heat through the aquifer and/or ground through the flow of steam and combustion product gases and/or hot air and/or hot water to regions affected by the contaminants, and by drawing the flow to other well sites by which the contaminants are removed by pumping and subsequent treatment. Some of the contaminants are thermally destroyed. The design of the well casing can be tailored to proportion the quantities of water and steam and gas delivered, with steam and gas pressure driving the vapors at various levels below ground.

Abstract: There is disclosed a process and apparatus for generating uniform filler metal droplets of a size of from 50 to 1000 .mu.m for deposition onto small metal parts and components thereby producing localized heating and melting of the components to be joined.

Abstract: A supersonic gas flow is employed with a virtual impactor to separate fine particles completely from the gas. The carrying gas and fine particles are accelerated to supersonic speeds and then impacted against a virtual impactor. When the supersonic stream strikes the virtual impactor, a shock wave forms in the gas stream near the impactor surface. The carrying gas turns sharply away while the particles in the gas stream, carried by their inertia, continue in their original direction and pass into the virtual impactor. On the downstream side of the virtual impactor surface, a non-contaminating inert gas maintains a pressure equal to or greater than the pressure of the carrying gas between the virtual impactor surface and the shock wave.

Abstract: There is disclosed a novel process and apparatus for continuously producing very fine, ultrapure ceramic powders from ceramic precursor reactants in a self-sustaining reaction system in the form of a stabilized flame thereof to form ceramic particles and wherein the thus formed ceramic particles are collected in the absence of oxygen.

Abstract: A method and apparatus are employed to detect the onset of soot or smoke formation in a flame exhaust. A pair of oppositely charged electrodes are placed in a flame located where soot formation is likely to occur. Varying voltages are applied across the electrodes and the limiting current, as the voltage is increased, called the saturation current, is measured. Generally, the saturation current decreases for higher fuel-to-air ratios in non-sooting flames. When the threshold for soot formation is approached, a definite saturation current is no longer observed and the current through the electrodes increases rapidly with increasing applied electrode voltage. The detection of the rapidly increasing current during sooting conditions is indicative of the formation of the soot itself.

Abstract: A mass spectrometer is employed to analyze the boron and phosphorus content in silicon or a silicon compound such as SiH.sub.4 or SiHCl.sub.3. According to the preferred embodiment a first non-seeded flame is surrounded by a second seeded flame. The velocities of both flames are approximately the same so that the boundary between them is relatively stable. Small quantities of BO.sub.2.sup.- and PO.sub.2.sup.- are formed in the second flame seeded with a silicon compound. The positively charged inlet orifice of a mass spectrometer is placed in the first flame sufficiently close to the boundary so as to attract negative ions into the instrument. In this manner the relatively small orifice of the sampling cone is not plugged by the SiO.sub.2 particles that are generated in the outer flame and the boron and phosphorus content of the silicon or silicon compound can be measured.

Abstract: A grinding wheel is used to pulverize solid test samples and propel particles thereof into a flame for analysis by an instrument such as a mass spectrometer. The sample is attached to one end of a pivoted lever arm. The other end of the lever arm is connected to a solenoid. Activation of the solenoid brings the sample into contact with the rotating grinding wheel. The solid particles produced by the wheel are propelled into the flame through a slot in an intermediate draft shield. The sampling cone of a conventional mass spectrometer or similar instrument may be placed in the flame to analyze the nature of the test materials. The device may also be used to inject test particles into the air or gas feed stream ahead of the flame if desired.