Abstract: A system for detecting an incipient tumor in living tissue such as that of a human breast in accordance with differences in relative dielectric characteristics. A generator produces a non-ionizing electromagnetic input wave of preselected frequency, usually exceeding three gigahertz, and that input wave is used to illuminate the living tissue, being effectively focused into a small, discrete volume within the tissue to develop a non-ionizing electromagnetic wave at that position. The illumination location is moved over a portion of the living tissue in a predetermined scanning pattern. Scattered signal returns collected from the living tissue are collected to develop a scattered return signal. The scattered return signal is employed to detect any anomaly, caused by differences in relative dielectric characteristics, that is indicative of the presence of a tumor in the scanned living tissue.

Abstract: A method for removing a contaminant from a treatment region of a contaminated region of a site in the earth having water therein and being contaminated with the contaminant includes heating the earth by establishing an electric field through the treatment region. The electric field gives rise to an electric conduction or displacement current through the treatment region. The electric current electrically heats at least a portion of the treatment region to a temperature below the boiling point of water to evaporate the water. A vacuum is drawn in a nether region of the site to collect water vapor evolved from the water and contaminant vapor evolved from the contaminant by movement of air from the surface of the earth, while the water vapor strips the contaminant from the earth. The contaminant vapor is disposed of in an innocuous manner.

Abstract: Infectious medical materials is rendered innocuous by heating heterogeneous medical materials having wet and dry portions with a radio frequency electric field. The medical materials are exposed to the radio frequency electric field in order to heat the medical waste. The medical waste may include sorted medical or veterinary waste which after heat treatment may be shredded and recycled.

Abstract: Improved methods and apparatus are disclosed for confining ohmic heating currents to a subsurface formation in the use of in situ ohmic heating for recovery of volatile and semi-volatile materials, such as hazardous waste, hydrocarbon-like materials, and valuable minerals having thermally responsive properties. Spacing between emplaced electrodes and the number of electrodes employed are controlled to cause coupling between electrodes for more uniform and higher temperature heating. Electrode designs are disclosed which suppress spurious earth currents which would heat other formations not of interest. Suppression of electrode end currents is accomplished by the use of distinct rings of insulation, control of the applied potential along the electrode, and injection or withdrawal of fluids at distinct locations along the electrode.

Abstract: A.C. electrical heating system for heating a fluid reservoir (deposit) in the vicinity of a mineral fluid well, usually an oil well, utilizes A.C. electrical power in a range of 25 Hz to 30 KHz. The well has a borehole extending down through an overburden and into a subterranean fluid (oil) reservoir. There is a well casing including an upper electrically conductive casing around the borehole in the overburden, and at least one electrically conductive heating electrode located in the reservoir to deliver heat to the reservoir. An electrically insulating casing is interposed between the upper casing and the heating electrode. An electrically isolated conductor extends down through the casing. The heating system further includes an electrical A.C. power source having first and second outputs; the power source is usually located at the top of the well.

Abstract: Infectious medical materials are rendered harmless by heating heterogeneous medical materials having wet and dry portions with a radio-frequency electric field. The medical materials may be comminuted prior to heating. The medical materials are exposed to the radio-frequency electric field in order to heat the medical materials. The medical materials may include sorted medical or veterinary waste which after heat treatment may be recycled.

Abstract: Ionic contact is established and maintained between electrodes and soil in ohmic heating of a subsurface formation for recovery of volatile and semi-volatile materials, such as hazardous waste, hydrocarbon-like materials, and valuable minerals having thermally responsive properties. A compressed, dry sponge is wrapped around an electrode, which is then inserted into a bore hole. A conductive liquid is added to the bore hole, causing the sponge to swell, creating a stable and substantial interface for the flow of heating currents.

Abstract: Infectious medical materials are rendered harmless by heating heterogeneous medical materials having wet and dry portions with a radio-frequency electric field. The medical materials may be comminuted prior to heating. The medical materials are exposed to the radio-frequency electric field in order to heat the medical materials. The medical materials may include sorted medical or veterinary waste which after heat treatment may be recycled.

Abstract: Infectious medical materials are rendered harmless by heating heterogeneous medical materials having wet and dry portions with a radio-frequency electric field. The medical materials are exposed to the radio-frequency electric field in order to heat the medical materials to inactivate microorganisms thereon. The medical materials are then irradiated with gamma radiation to inactivate microorganisms remaining viable thereon after application of the radio-frequency electric field.

Abstract: Methods and apparatus for treating waste with radio frequency include a wall defining a radio frequency treatment chamber through which waste may be passed. A source of radio frequency energy energizes the radio frequency treatment chamber to heat the waste and drive off vapors therefrom leaving solid residue to be disposed of. A guard heater and/or insulation maintains the wall at substantially the same temperature as the waste being heated by the radio frequency to prevent vapors from condensing on the waste.

Abstract: Infectious medical materials is rendered innocuous by heating heterogeneous medical materials having wet and dry portions with a radio frequency electric field. The medical materials are exposed to the radio frequency electric field in order to heat the medical waste. The medical waste may include sorted medical or veterinary waste which after heat treatment may be shredded and recycled.

Abstract: Improved methods and apparatus are disclosed for confining ohmic heating currents to a subsurface formation in the use of in situ ohmic heating for recovery of volatile and semi-volatile materials, such as hazardous waste, hydrocarbon-like materials, and valuable minerals having thermally responsive properties. Spacing between emplaced electrodes and the number of electrodes employed are controlled to cause coupling between electrodes for more uniform and higher temperature heating. Electrode designs are disclosed which suppress spurious earth currents which would heat other formations not of interest. Suppression of electrode end currents is accomplished by the use of distinct rings of insulation, control of the applied potential along the electrode, and injection or withdrawal of fluids at distinct locations along the electrode.

Abstract: An energy-efficient method for killing noxious biological organisms (bacteria, insects, etc.) in contaminated materials ranging from liquid, semi-liquid, and solid foods pharmaceuticals and hospital wastes comprises passing the contaminated material through an exposure chamber; screening, comminution, addition of fluid or foam, limited heating, or other pretreatment steps may be required. As it flows through the exposure chamber the contaminated material is subjected to a nonuniform, high-intensity electric field; in that chamber, excessive current flows, including arcing and current "streamers", are suppressed by limiting the current density. The amplitude of the applied current density and the electric field in the exposure chamber are controlled, in accordance with the conductivity and/or dielectric constant of the contaminated material, so that the electric field intensity is of the order of 3,000 volts/centimeter or more.

Abstract: Optimum antenna-like exciters for heating earth media which may be used to recover hydrocarbons. A high frequency power supply is connected to an exciter emplaced in the subsurface formation which radiates high frequency power. The exciters include one or more conducting cylinders which make up monopole and dipole antenna-like apparatus. Substantially uniform heating of the subsurface formation is provided thus suppressing excessive heating of edge and power input regions. The equal distribution of electric fields eliminates intense electric fields which would normally exist thus mitigating excessively heated regions and providing substantially uniform heating of the subsurface formation.

Abstract: Electrical power sources and systems for heating in or adjacent to an oil well or other mineral well, or for heating other earth media, each comprising an A.C. heating generator that generates an A.C. heating current at a selected heating frequency substantially different from the conventional 50/60 Hz frequency used by power companies; the heating generator may comprise an A.C. to D.C. converter for developing an intermediate D.C. output of predetermined amplitude from a conventional 50/60 Hz A.C. input, and a solid state switching circuit for repetitively sampling the D.C. output of the converter at the selected heating frequency, usually in a range of 0.01 Hz (or even lower) up to about 35 Hz. A heating rate control varies the energy content and the frequency of the A.C. output to suit well requirements.

Abstract: Electrical heating system for mineral wells, particularly oil wells, in which the reservoir or "pay zone" is heat stimulated or some well components (e.g., the tubing) are heated, or both, by electrical power supplied to a multi-perforate electrode have the operating efficiency enhanced by effectively terminating the heating electrode, at both its top and bottom, at a distance inwardly of the pay zone equal to at least three times the diameter of the well casing. In some systems the electrical power connection to the main heating electrode is made through a section of the production tubing of the well, with an electrical contactor interconnecting the tubing and the electrode in the level of the pay zone; these systems also provide electrical isolation, within critical height limits, for the production tubing and the pump rod. Delivery of electrical power downhole of the well may be accomplished through an electrical cable, which may or may not be appropriately armored.

Abstract: Method and apparatus for corrosion inhibition in an electromagnetic heating system for heating a portion of a mineral fluid deposit adjacent an oil well or other mineral fluid well, in situ. The preferred apparatus includes a power source, that develops a high amperage heating current, over 100 amperes, at a heating frequency usually in a range of from 0.01 Hz or lower to 35 Hz, in a heating circuit that includes a main heating electrode downhole of the well and a return electrode. The power source also supplies a very low amplitude, controlled D.C. bias current to those electrodes, maintaining the main electrode at a neutral or negative polarity for corrosion protection. The D.C. bias current is monitored and maintained below a given minimum level, usually about one ampere, to extend the effective life of the return electrode and to minimize corrosion protection costs.

Abstract: Corrosion inhibition apparatus in an electromagnetic heating system for in situ downhole heating in an oil well or other mineral fluid well that includes an A.C. power source for a high amperage, low frequency heating current (e.g. over 50 amperes at 0.01 to 35 Hz) and a D.C. bias source for generating a low amplitude (e.g., less than one ampere) current for corrosion inhibition, both sources connected to a downhole electrode. The bias source includes at least one semiconductor device, connected in the main A.C. heating circuit, in a bias circuit that develops a net D.C. voltage differential of the polarity required for corrosion inhibition in response to the A.C. heating current.

Abstract: To provide confinement in a porous medium in the earth, a limited region of the porous medium is heated to drive substantially all of the free water from open spaces of the medium in the region. After heating, liquid material is introduced into the open spaces in the medium, which liquid material will set into a substantially solid structure. The liquid material is then set in the open spaces to form a substantially solid structure in the medium in the region.

Abstract: An electrical heating system for an oil well of the kind comprising a well bore extending through and below an oil producing formation to afford a rathole of substantial depth, the well including an electrically conductive first casing section from the earth surface down through the overburden, an electrically conductive second casing section continuing down through the oil producing formation, and a third casing section in the rathole. The first and second casing sections are usually steel pipe. An electrical power supply is connected to primary and secondary electrodes for conductive heating of a portion of the oil producing formation; the primary electrode is an uninsulated portion of the second casing section. The third casing section constitutes an insulator for electrical isolation of the rathole.