Abstract: A method of electromagnetic heating in situ recovers liquid hydrocarbons from an oil shale formation containing kerogen in an inorganic matrix where the formation is substantially impermeable to fluids under native conditions. A block of the oil shale formation is substantially uniformly heated in situ with electromagnetic power to a temperature of about 275.degree. C. where there is pyrolysis of a portion of the kerogen to gas and shale oil at a pressure sufficient to overcome the capillary pressure of the shale oil in the matrix, thereby providing substantial fluid permeability to the formation. The gas thereupon escaping from said block and the shale oil driven thereby are recovered, thereby further increasing the permeability of the formation.

Abstract: The effects of radio frequency electric field peaking in the earth formations surrounding a conductor excited by radio frequency energy in the controlled in situ heat processing of hydrocarbonaceous earth formations are mitigated by providing an inert buffer region around the conductor to which radio frequency electromagnetic energy is supplied to produce an electric field within the earth formations. A portion of the earth formations is removed to accommodate insertion of the conductor at a desired location in the earth formations and to provide a buffer region between the conductor and the surrounding earth formations. The conductor is supported at the desired location in spaced relationship to the surrounding earth formations, the buffer region encompassing the principal region of the electric field enhancement region around the conductor where the probability of breakdown in the earth formations over the period of application of the radio frequency energy would be above a tolerable level.

Abstract: A transducer head configuration is utilized which is operable by means of recording pulses of extremely short duration and of low duty cycle. Provision is made for reading the recorded magnetization between recording pulses and correcting same pulse prior to substantial movement of the record medium relative to the transducing gap.

Abstract: A system and method for the controlled in situ heat processing of hydrocarbonaceous earth formations involves the application of electromagnetic energy at a selected frequency or at selected frequencies to a waveguide structure formed by electrodes bounding a particular volume of hydrocarbonaceous material. Terminating one end of the structure with different impedances at different times produces electric field standing waves of different respective phase at that end at a selected frequency. Two standing waves substantially 90.degree. out of phase in formations having relatively uniform dielectric properties result in substantially uniform application of heating power if the product of the amplitude-squared of the electric field standing wave and dwell time is substantially the same in each of the two modes. Feeding the line at both ends provides partial offset for attenuation. Various desired controlled heating patterns other than uniform may be effected by utilizing different dwell times or applied fields.

Abstract: In one exemplary embodiment errors due to tape flutter are overcome by recording along with the analog signal clock pulses having a rate sufficient for sampling of the highest frequency component of the analog signal. Then on playback, the reproduced clock pulses control sampling and storage of samples of the reproduced analog signal. By reading out the samples from storage at a uniform clock rate, the effect of flutter on the reproduced signal is eliminated. In another example the recorded clock rate overcomes tape skew and other mechanical irregularities in recording and reproducing multiplexed analog or digital data.

Abstract: An optical transducer system reproduces a videodisk record by rotating the disc at a low speed. A record guiding means is comprised of a ribbed gate region. The ribs engage the disc on opposite margins of the optical images recorded on the disc and extend in a circumferential direction.

Abstract: A video disc record having a spiral video record track which can provide reproduced video signals with a desired frame rate such as thirty frames per second while the disc record is rotated at a very low speed such as two revolutions per minute. A preferred transducer machine uses a pulsed light source to supply successive light images to a video camera readout. Control signals are recorded on helical control tracks so that reproduction thereof facilitates the generation of a desired standard video signal from the video camera.

Abstract: A capstan having one or more annular slots with transducer heads therein for scanning of respective channels of a tape record medium, preferably with a vacuum source coupled with the slot or slots and for example an insert shaped to break the vacuum at a tape release position of the slot. A capstan pressure roller if used may be relieved at the groove or grooves and at locations corresponding to the edges of the tape path about the capstan.

Abstract: The disclosure describes a technique for uniform heating of relatively large blocks of hydrocarbonaceous formations in situ using radio frequency (RF) electrical energy that is substantially confined to the volume to be heated and effects of dielectric heating of the formations. An important aspect of the disclosure relates to the fact that certain hydrocarbonaceous earth formations, for example raw unheated oil shale, exhibit dielectric absorption characteristics in the radio frequency range. In accordance with the system of the invention, a plurality of conductors are inserted in the formations and bound a particular volume of the formations. The phrase "bounding a particular volume" is intended to mean that the volume is enclosed on at least two sides thereof. Electrical excitation is provided for establishing alternating electric fields in the volume.

Abstract: The disclosure describes a technique for uniform heating of relatively large blocks of hydrocarbonaceous formations in situ using radio frequency (RF) electrical energy that is substantially confined to the volume to be heated and effects dielectric heating of the formations. An important aspect of the disclosure relates to the fact that certain hydrocarbonaceous earth formations, for example raw unheated oil shale, exhibit dielectric absorption characteristics in the radio frequency range. In accordance with the system of the invention, a plurality of conductors are inserted in the formations and bound a particular volume of the formations. The phrase "bounding a particular volume" is intended to mean that the volume is enclosed on at least two sides thereof. Electrical excitation is provided for establishing alternating electric fields in the volume.

Abstract: A portable video recording system, particularly for amateur video reporting operations and the like, employing a camera station and a recording station which are physically separated from one another and connected over wireless links, the camera station being of a size to be readily manually carried on the person and designed merely to produce video and associated signals and transmit the same by radiation of a high frequency carrier, light or other signal to the recording station, and processed by receiving means thereat to derive the signals to be recorded, the recorder being operatively controlled from the camera station, whereby both the camera and the recorder of the remote recording station are under the control of the camera operator. Signals are also transmitted from the recording station to the camera station for indicating to the camera operator the operation of the recorder.

Abstract: A video tape cartridge of endless loop configuration capable of tape speeds suitable for longitudinal scan television recording while providing one hour or more of continuous playing time on one-quarter inch width tape. In an illustrative embodiment tape guides within the cartridge are shiftable from a loading position to an operating position without a substantial change in the length of the tape path to accommodate scanning of the tape at a tensioned loop closely adjacent the capstan. In operating condition, the tape is engaged with the capstan at one side thereof so that the capstan pulls tape along an incoming tape path from the inner side of the coil, the tape passing about the tensioned loop past the transducer head and again engaging the capstan for supply of the tape to the outer side of the coil along an outgoing tape path, with a tape drag applying a substantial drag force to the tape at the incoming tape path between the reel and the capstan.

Abstract: A video tape cartridge of endless loop configuration capable of tape speeds suitable for longitudinal scan television recording while providing one hour or more of continuous playing time on one-quarter inch width tape. In an illustrative embodiment tape guides within the cartridge are shiftable from a loading position to an operating position without a substantial change in the length of the tape path to accommodate scanning of the tape at a tensioned loop closely adjacent the capstan.

Abstract: A portable video recording system, particularly for amateur video recording operations and the like, employing a camera station and a recording station which are physically separated from one another and connected over a wireless link, the camera station being of a size to be readily manually carried on the person and designed merely to produce video and associated signals and transmit the same by radiation of a high frequency carrier signal to the recording station, and processed by receiving means thereat to derive the signals to be recorded, the recorder being operatively controlled from the camera station, whereby both camera and the recorder of the remote recording station are under the control of the camera operator.

Abstract: Antifertility drug complexes which have enhanced effectiveness and prolonged release of the antifertility drug. The complex includes an antifertility drug, a polybasic acid and a polyvalent metal ion. The antifertility drug is in the form of a basic amine derivative.

Abstract: One embodiment of video transducing system supplies a reproduced video signal with compensated amplitude response so as to exhibit a substantial phase advance for recorded half wavelengths less than the thickness of the magnetizable layer, and a phase correcting network is inserted between the playback winding and the playback amplifier.In a further embodiment, amplitude and phase are partially compensated such that there is a substantial amplitude fall off and a moderate phase advance at the highest frequencies of the useful range, and such that the leading edge of a step function when played back has an overshoot of approximately one to six decibels.

Abstract: A longitudinal scan transducing apparatus for use with a television receiver comprising a magnetic transducer head having transverse conductors for supplying high frequency bias, high frequency bias synchronized with the horizontal line rate, head shifting and tape reversal features, and television set adapter circuitry for supplying a wide-band video signal and for stabilizing reproduced sync signals.

Abstract: A blank for forming a stencil screen for silk screen or electrostatic stencil printing is disclosed. The screen includes a resilient, high tensile strength, porous substrate such as a monofilamentary nylon or stainless steel 200-mesh screen. A light radiation absorbent, self-combustible, ink-resistant, ink-impervious and tough film is applied to the screen, suitably a combustible black nitrocellulose film or a black cellulose ether film containing finely dispersed nitrate or perchlorate. The film is selectively removed by directly pulsing high-intensity light of over 10 joules per square inch for a short duration of 1 to 50 milliseconds in the form of an image pattern to ignite and completely combust the film only in said areas during the duration of the pulse.

Abstract: The disclosure describes a technique for uniform heating of relatively large blocks of hydrocarbonaceous formations in situ using radio frequency (RF) electrical energy that is substantially confined to the volume to be heated and effects of dielectric heating of the formations. An important aspect of the disclosure relates to the fact that certain hydrocarbonaceous earth formations, for example raw unheated oil shale, exhibit dielectric absorption characteristics in the radio frequency range. In accordance with the system of the invention, a plurality of conductors are inserted in the formations and bound a particular volume of the formations. The phrase "bounding a particular volume" is intended to mean that the volume is enclosed on at least two sides thereof. Electrical excitation is provided for establishing alternating electric fields in the volume.