Abstract: A polymer concrete pipe liner is formed from a fluidized, but substantially waterless cement containing mixture applied to the pipe interior. The mixture is composed of inorganic cement particles, a liquid styrene mixture and a minor amount of one or more poly-olefinically unsaturated co-monomers. The mixture substantially excludes acrylonitrile and acrylamide. The co-monomers are preferably selected from a group including trimethylolpropane-trimethacrylate, divinyl benzene, hexadiene, and polyvinylsiloxanes. Mixing the liquid and solid components forms a slurry which is transferred to a pipe interior. Transfer properties can be controlled by particulate gradation, dissolved polymers, and rheology control additives. The pipe is then spun to centrifugally cast the liner. The composition avoids the need for high temperature curing and toxic reactive unsaturates to co-polymerize and cross-link polystyrene.

Abstract: A catalyst for use in acid catalyzed chemical conversion processes such as hydrocarbon conversion processes comprises zeolite beta and a dealuminated Y zeolite having an overall silica-to-alumina mole ratio greater than 6.0, preferably LZ-210 zeolite. A preferred catalyst contains nickel and molybdenum hydrogenation components in addition to the zeolite beta and the LZ-210 zeolite and, when used in gasoline hydrocracking, is found to be more active and selective for both light and heavy gasoline than a commercially available gasoline hydrocracking catalyst containing nickel and molybdenum hydrogenation components and a single steam-stabilized Y zeolite.

Abstract: Radioactivity and fluoride ion are inhibited or prevented from precipitating in scale formed from a geothermal brine by adding a dispersant to the cooling brine solution. Preferred dispersants include polyacrylates and polyphosphonic acids.

Abstract: Hydrocarbon fuels, especially diesel fuel compositions, contain orthoesters to reduce particulate emissions therefrom when combusted in an internal combustion engine.

Abstract: Gels containing gas precursors and/or pathways are used to selectively reduce the flow of aqueous fluids with respect to the flow of nonaqueous fluids to enhance the recovery of the nonaqueous fluids from subterranean formations. The gels, while stable at reservoir conditions, are also readily degraded by gel degrading agents such as acids and therefore are also employed as fail-safe gels in subterranean gel treatments. In another embodiment, selective permeability is restored to a previously treated well by injecting a gas into the previous treated portions of the subterranean formation to displace any aqueous fluid obstructing the passage of the nonaqueous fluid through the polymer-coated pores or gel.

Abstract: Polymers (and especially hydroxyethylcellulose) are crosslinked using a lanthanide as a crosslinking agent. The crosslinked polymers have utility in well completion, well stimulation, enhanced oil recovery, and subterranean fluid containment operations.

Abstract: NO.sub.x removal is accomplished by contacting a NO.sub.x -containing stream under reducing conditions with a urea-ammonia-water composition.

Abstract: Soluble salts are prevented from precipitating from a brine concentrate produced from the flashing a geothermal brine by diluting the brine concentrate with preconditioned condensate. The pH of the condensate is first adjusted to within two pH units of brine concentrate. Then concentration of sulfide ion is reduced by oxidizing sulfide to sulfate by exposure to air for a period of time sufficient to oxidize a substantial portion of the sulfide, but short enough to prevent a substantial concentration of oxygen from dissolving in the condensate. The preconditioned condensate is then mixed with the brine concentrate to form an injection stream. The injection stream is then injected into the earth.

Abstract: Aqueous thiocarbonate solutions are stabilized by the addition of base, sulfide and/or polysulfide, and the stability and safety of the more concentrated solutions containing 1 weight percent or more equivalent CS.sub.2 as a thiocarbonate are achieved as reflected by significant reduction of CS.sub.2 partial pressure in such solutions.

Abstract: A geothermal brine containing recoverable metals is contacted with at least two electrodes, across which an electrical potential is applied to cause the metals to deposit upon said electrodes. The invention is particularly useful for the recovery of iron, zinc, lead, and manganese from a brine from a geothermal aquifer such as is found at the Salton Sea in California.

Abstract: Cellulosic materials are physically and/or chemically modified by contact with a combination of urea and sulfuric acid in which at least 25 percent of the sulfuric acid is present as the monourea adduct of sulfuric acid. The cellulosic materials thus treated possess uniquely modified physical and chemical properties. The methods of the invention can be employed to weaken the physical structure of the cellulosic material and thereby to assist in clearing land of vegetation and vegetation residue and in compacting and other processing of waste cellulosic materials. The methods of the invention can also be employed to increase the food value of cellulosic materials for animals, including humans, and, in particular, to increase the food value of such materials for ruminant mammals.

Abstract: A short pulse of laser excitation and a synchronized gating time control of a fluorescence spectrograph detector are combined with a microscope, precise focusing and delivery optics, multi-mode illumination means, cooling, and temperature controls to form a new microspectrophotometry system. The gating control can block detection of any unwanted excitation radiation, such as nearly instantaneous (within 10.sup.-12 seconds) emissions after the sample is pulse excited and delayed emissions (after 10.sup.-7 seconds) after the sample is pulse excited. The gating also allows delayed emissions to be separately isolated. The microscopic focusing, pulse excitation and time segregation of detected emissions achieves a new level of precision in the detected structural spectra and property measurements not generally achievable for composite samples by prior art methods and devices.

Abstract: High purity ammonia is quantitatively produced from urea by reaction with water in the presence of acid. A major advantage of the invention is that urea can be safely transported to a conversion site, then converted to ammonia. The net result is that high purity ammonia is available wherever it is needed without the toxic hazard presented by transporting ammonia.

Abstract: Oil production from a fractured, oil-bearing subterranean formation is enhanced by sequentially injecting (i) a wettability reversal agent-containing fluid and (ii) an overflush fluid through a well and into the formation. The well is then place into production after allowing a sufficient period of time for (a) the matrix face of the formation to change from preferentially oil wet to preferentially water wet and (b) a displacing fluid (e.g., hot water, steam) to imbibe into the fractured matrix and displace the oil from the matrix into the fracture cracks.

Abstract: Organic tracers are employed to monitor the movement of subterranean fluids. These organic tracers are (a) stable at elevated temperatures, (b) capable of being detected at low concentrations, and/or (c) not adversely affected by the make-up of at least one subterranean formation. In addition, a plurality of these tracers can be measured by a single analytical technique.

Abstract: Gels stable in a subterranean formation at a temperature greater than about 175.degree. F. are formed using, inter alia, a stabilizing agent (e.g., a buffer having a buffering capacity at a pH of at least about 8 and/or a chelating agent).

Abstract: The concentration of amorphous silica in an aqueous solution is monitored to determine a concentration above which silica will precipitate. The precipitation concentration is data processed with a means for data processing by solving the Setchnow equation for aqueous solutions containing silica. The means for data processing generates a signal that, if need be, can be used to automatically adjust the parameters of the system to prevent silica precipitation or to carefully control the precipitation rate. An alternative embodiment provides a method for determining amorphous silica concentration, then data processing the solution to the Setchnow equation, generating a signal, and adjusting the parameters of the system. The apparatus and method of this invention are particularly useful in geothermal power plants.

Abstract: Polymers (and especially hydroxyethylcellulose) are crosslinked using a lanthanide as a crosslinking agent. The crosslinked polymers have utility in well completion, well stimulation, enhanced oil recovery, and subterranean fluid containment operations.

Abstract: Real-time monitoring of a target production zone is followed by an oscillatory drilling path to create a borehole having improved zone drainage capability. Real-time monitoring uses geophones placed in adjacent wells or the well being drilled. The drilling process itself generates the seismic signals. When the geophones are located in the well being drilled, the seismic signals are transmitted from downhole to surface through intermittent pressurization of drilling mud. Once drilling penetrates the zone, the oscillatory path is followed by fracturing to improve fluid drainage paths and minimize additional drilling.

Abstract: A seismic recording system comprises a multichannel recorder connected to a cable formed from a plurality of signal conductors. Each of the signal conductors is connected to a different channel of the recorder. The cable has a plurality of takeouts located at spaced distances along its length. Each of the takeouts is connected to a different signal conductor of the cable. The system further includes a switch operably connected to one of the takeouts for selectively interconnecting the takeout and any one or more of several seismic detector connections upon receipt of a remotely generated signal. The system also includes a number of detector conduits, each of which has one end operably connected to a different one of the seismic detector connections of the switch. Each detector conduit has at least one geophone located along its length and operably connected thereto. A control is provided for transmitting a signal to a switch. The switch interconnects a selected group or groups of geophones with the recorder.