Abstract: A recoverable article comprises a fabric having zones of different or uniformly varying recovery forces or ratios. The fabric can be made impervious and used for environmental protection.

Abstract: A duct seal for sealing a duct (4) to a substrate (20) such as a feedthrough comprises a sealing member (6), a biasing member (8), such as a wrapped spring sheet and an insert (12) positioned between the substrate (20) and the sealing member (6). The biasing member (8) can be operated, through the insert (12) from the outside of the duct. When the substrate is a feedthrough (20), for example, it is advantageous that the biasing member (8) is operated through the insert rather than through the feedthrough (20) itself, since it allows the feedthrough to be temporarily sealed against contaminants.

Abstract: A wraparound recoverable article comprises longitudinally opposed edge regions which can be brought together to close the article. On recovery of the article a configurational change of or adjacent the closure member can be seen. This can be used as a temperature indicator to show that recovery is complete. Preferably the configurational change is a rotation of the material at the edge regions which results in a white line extending along the length of the closure, and which is not visible before recovery, becoming visible.

Abstract: A duct seal (1) especially for sealing about four cables, contains a spring (8) which when operated radially expands that part of the duct seal that is to seal to a wall etc (2). The cables are sealed by heat-shrink outlets (7) of the duct seal (1). The spring (8) is operated after heating the part of the duct seal in which it lies. Heating may soften the material of the seal and activate an adhesive (9).

Abstract: A heat recoverable article comprises a fabric cover (2) which has an aperture (4) therein around the edges of which is clamped a rivet (2), fixed so as to prevent pull-out of the fabric fibres on recovery of the cover. The article is particularly suitable for use as a pressurized splice case since a valve can be passed through the aperture in the cover. The valve can be secured directly to the cover, or to a correspondingly apertured liner positioned within the cover.

Abstract: An apparatus and process are described which can measure the strength of an evanescent field at the surface of an optical fiber. Light is injected into an end of the optical fiber while the portion of the fiber to be tested is contacted with a material having a higher index of refraction than the optical fiber. The amount of light lost, i.e., coupled out of the fiber, is a function of the evanescent field strength at the cladding surface of the optical fiber. This loss can be correlated with optical fibers which have thicker and thinner claddings to determine the thickness of the cladding and/or the extent of removal of the cladding by, for example, etching.

Abstract: A cable connector assembly capable of mating to an armored optical cable and providing a hermetically sealed electronics cavity is described. A connector assembly provides a means for placing electronics in an electronics cavity. The electronics are capable of converting electrical signals to optical signals or optical signals to electrical signals within the electronics cavity in the connector assembly so that optical to optical matching of optical fibers is unnecessary. The connector contains a means for anchoring the armoring wire of the armored optical cable and at least two-spaced apart means for sealing the electronics cavity from leakage of pressure around the optical fiber cable. Furthermore, the connector assembly contains a means for passing the optical fiber core through a breakable link before termination in the electronics cavity.

Abstract: An optical-electrical geophone which generates a binary signal is described. The geophone utilizes an optical fiber for the return transmission of a light source in the geophone. The geophone contains a light chopping means which oscillates in response to vibrations imparted into a geologic formation. As the chopping means such as a baffle or a tubular member vibrates, it chops the light signal and creates an on/off light pattern, i.e., binary signal. The light passing through a slit in the baffle or tubular member is returned to the seismic vehicle through an optical fiber for further processing. The optical-electrical geophone creates a binary signal directly without the use of clipping electronics and magnets or coils used in conventional geophones.

Abstract: An apparatus and process of analyzing samples using reflected and/or emitted radiation is described. The apparatus includes a means for containing the sample and moving the sample and/or a reflector at a uniform rate through a fixed plane. A radiation source irradiates the core sample. The reflected or emitted radiation is directed onto a detector means capable of forming electrical signals which are digitally encoded and recorded on a digital recorder for further interactive analysis and/or processing.

Abstract: An electrochromic device which incorporates a reversibly color-changing organic polymer film as the display electrode. The display polymer film is capable of undergoing reversible oxidation and/or reduction to a charged, colored, conductive state. Upon reversing the charge, the polymer returns to its virgin color. The display films are comprised of linear fused heterocyclic ring systems, optionally with connecting units, or linear monocyclic ring systems and connecting units. The device requires low currents to operate and switch from the virgin state to the colored state. It also can optionally be operated to exhibit several colors.

Abstract: An improved cyclic steam injection process for recovering hydrocarbons from a subterranean formation. The process includes the use of alpha-olefin sulfonate dimer surfactants in the steam to form a foam-steam drive medium which is injected into the formation through an injection well to enhance the recovery of hydrocarbons from said well when it is in a production well mode of operation.

Abstract: A ruggedized grated optical fiber is described. The gratings in the fiber permit its use as a reflector or an interferometer when pairs of gratings having the same reflectance characteristics are spaced along the optical fiber. The ruggedized fiber comprises an optical fiber having the outer cladding removed down to an inner sheathing wherein a portion of the inner sheathing is further removed to expose the core wherein evanescent waves are encountered. The gratings are formed in this core. Surrounding the gratings and connected to the inner sheathing are two semi-tubular sections which are affixed to the inner sheathing and hermetically sealed around the gratings.

Abstract: A frequency shifted cavity apparatus for electromagnetic radiation. The cavity filters electromagnetic radiation wherein the instantaneous frequency increases and changes non-linearly in time. The cavity can optionally include an optical amplifier with sufficient gain to cause oscillation of at least one cavity mode.

Abstract: An improved non-condensible gas injection process for recovering hydrocarbons from a subterranean formation. The process includes the use of alpha-olefin sulfonate monomer and alpha-olefin sulfonate dimer surfactants along with the gas to form a gas-foam drive medium which is injected into the formation through at least one injection well to enhance the recovery of hydrocarbons from at least one production well.

Abstract: Two- and three-terminal ternary III-V two-color and three-color solar cells which incorporate GaAs.sub.1-x-y P.sub.x Sb.sub.y transparent window layers are described. The window layers lower the surface recombination of the incident homojunction layer.

Abstract: An improved non-condensible gas injection process for recovering hydrocarbons from a subterranean formation. The process includes the use of alpha-olefin sulfonate surfactants along with the non-condensible gas to form a gas-foam drive medium which is injected into the formation through at lest one injection well to enhance the recovery of hydrocarbons from at least one production well.

Abstract: The invention covers a process of forming gratings in optical fiber. The gratings are formed at depth wherein the evanescent waves of the optical fiber are encountered. The process permits the fabrication of gratings in the optical fiber that reflect light of predetermined wavelengths. The grated optical fibers can be used as reflectors or interferometers when the gratings are used in pairs.

Abstract: An improved steam injection process for recovering hydrocarbons from a subterranean formation. The process includes the use of alpha-olefin sulfonate dimer surfactants in the steam to form a foam-steam drive medium which is injected into the formation through at least one injection well to enhance the recovery of hydrocarbons from at least one production well.

Abstract: An armored optical cable and process of manufacturing is described. The armored optical cable exhibits minimal inelastic elongation in response to tension at elevated temperatures and is capable of withstanding harsh ambient conditions. The armored optical cable is fabricated in a unitary operation with a central bundle of one handedness surrounded by at least one outer armor layer of opposite handedness substantially torque balanced to the handedness of the central bundle.

Abstract: An armored cable containing a hermetically sealed tube incorporating an optical fiber is described. The armored optical cable exhibits minimal inelastic elongation in response to tension at elevated temperatures and is capable of withstanding harsh ambient conditions.