Abstract: A method for resisting corrosion while conducting a flow of hot corrosive geothermal fluid, particularly brine, comprises flowing the fluid through fluid flow conducting elements, such as production pipe and fittings formed from a metastable beta titanium-base alloy. Preferably the element is formed of a beta and alpha titanium-base alloy formed by heating a particular composition to form a metastable beta titanium matrix and then heat treating the matrix to increase the tensile strength of the matrix by at least about 10,000 psi with a total minimum ultimate tensile strength being about 170,000 psi. The particular composition is comprised essentially of between about 2 and about 10 weight percent of one or more beta eutectoid elements selected from the group consisting of iron, manganese, chromium and cobalt, with weight percentage limits in each such individual element being respectively about 5, about 5.5, about 9 and about 4.

Abstract: Subterranean formations at temperatures above 250.degree. F. are acidized by introducing a solution of a halogenated hydrocarbon and an organic solvent and allowing the halogenated hydrocarbon to hydrolyze in an aqueous medium to form a hydrohalic acid. Corrosion of metals, e.g., well casing, is inhibited by the presence of the solvent. The acidizing solution can be introduced as a liquid or as a mist in a substantially anhydrous gas. The aqueous medium can be naturally present in the formation or can be introduced into the formation as a liquid or as a foam simultaneously with the acidizing solution.

Abstract: A process for reducing the concentration of fine, residual solids still remaining suspended in clarified geothermal brine overflow from a primary brine clarification stage in which hot, flashed, silica-rich geothermal brine, containing suspended silicious material, is gravity separated, comprises flowing the brine overflow from the primary clarification stage into a closed secondary clarifier vessel having an internal reaction well. Capacity of the secondary clarifier vessel provides a brine residence time in the vessel of between about 45 and about 150 minutes, the brine residence time in the reaction well being between about 10 and about 20 minutes. Brine in the vessel is blanketed with steam flashed from the brine to exclude air from the vessel. In the reaction well, the brine is contacted with a flocculating agent, preferably a cationic polyacrylamide having a molecular weight of at least about 1 million, in an amount of between about 0.25 and about 2 parts per million.

Abstract: A trigger lock for fuel pump nozzles at service stations comprises a relatively thin, flat piece of plastic, wood, metal, rubber or other material formed to have four pairs of opposing side edge regions. Opposite side edge regions are spaced apart different distances for different pairs so that the lock can be used to hold the nozzle triggers of different types of nozzles in a "full-on" pumping position, different pairs of side edge regions being used for nozzles having different trigger strokes. Preferably the spacings are 21/4, 21/2, 23/4 and 3 inches to enable use with most nozzles used by independent fuel distributors, by major distributors and for pumping No. 2 diesel fuel. In a variation, the trigger lock is incorporated into a vehicle fuel cap, the lock functioning as the portion by which the cap is gripped to remove and install the cap.

Abstract: Multi-time delay power controller apparatus for providing time-delayed power or control signals to associated electrical equipment, such as computers and disc drives, comprises a power stage configured for connecting to a conventional power outlet, a D.C. power supply connected to an interval D.C. voltage bus, an output stage having a plurality of time delayed outputs and a plurality of time delay timing stages connected in electrical series to one another between the D.C. voltage bus and ground. Each such timing stage includes a timing means, and a normally open control relay. Coils of odd numbered timing stages are connected to ground and of even numbered stages to the D.C. voltage bus. The timing stages are connected so that the timing out of one stage starts the timing of the next-in-sequence stage, timing of the first-in-sequence timing stage being started when the apparatus is turned on.

Abstract: A process is provided for reducing the total concentration of heavy metals, notably lead, copper and zinc, naturally occurring in silica-rich sludge precipitated from geothermal brine in a brine handling system such as a geothermal brine electric generating plant. The process includes washing the sludge with hot water to displace any brine entrapped in the sludge, dewatering the washed sludge and leaching the silicious solids residue with hydrochloric acid having a concentration of between about 2 and about 9 weight percent and an acid-to-sludge weight ratio between about 0.10 and about 0.33. The acid-sludge mixture is heated to a temperature of at least about 50.degree. and the leaching time is at least about one hour. The leaching solution is separated from the leached sludge and the solids residue are washed with water. Preferably the water used in both washing steps is condensate of steam derived from the geothermal brine. Effluent from the process is preferably combined with the brine for reinjection.

Abstract: A dual band array antenna is disclosed having interleaved waveguide and dipole arrays, each operating in a different frequency band. The orientation of the waveguides and dipoles is such that polarization of the signals of the two frequency bands is perpendicular to each other, thus reducing mutual coupling. The waveguides are used for the higher frequency band and their cutoff frequency is selected to be above the lower frequency band at which the dipoles operate, in order to reduce mutual coupling into the waveguides. In one embodiment the dipoles are printed on a substrate having a dielectric constant selected so that dipole spacing is the same as the waveguide spacing. This eliminates grating lobe formation in the radiation pattern of the waveguide array. A low pass filter is included in the dipole feed circuit to reject the frequencies at which the waveguides operate.

Abstract: A device is disclosed which simultaneously performs sync preamble correlation detection and frequency offset estimation functions for a spread spectrum receiver. The device performs a parallel frequency search, executed by a plurality of frequency sensitive circuit channels connected in parallel. These parallel circuit channels first apply phase corrections to the subcorrelator outputs and then linearly reintegrate the corrected outputs. In each channel the phase corrections applied to each successive subcorrelator output vary with the frequency offset subregions to which the channel is designed to match. By applying approximated phase corrections of 0.degree., 90.degree., 180.degree. or 270.degree. in lieu of the exact phase corrections required to remove the phase shift, the need for multiplication operations in the reintegration process is eliminated, as well as the need for storing large numbers of weighting coefficients.

Abstract: A process for regenerating media filters used to filter geothermal brine, especially flashed and clarified, silica-rich brine, comprises flowing steam through the filter in a backflush direction at a rate and for a time duration agitating the filter media and filtered-out material. The process includes, preferably after the steam flow is stopped, flowing brine, for example, filtered brine, through the filter in the backwash direction to flush out the material loosened and broken up by the steam scour and restratify the media bed components, and may include partially draining the filters prior to the steam scour. Preferably, the steam used for the steam scour is low pressure steam obtained from low pressure flashing of the brine being filtered. Steam flow rates are preferably between about 2 and about 10 SCFM per square foot of filter cross-sectional area in the region of the filter media; steam flow rate is preferably about 5 minutes after any steam quenching has ceased.

Abstract: A method is provided for combining a high pH steam condensate with a flow of a acidic geothermal brine from which the steam is extracted so as to inhibit the formation of suspended particulate matter, such as heavy metal sulfides, calcium carbonate and iron hydroxide, by the chemical reacting of such impurities as hydrogen sulfide and ammonia in the condensate with such impurities as heavy metals, iron and calcium in the brine. The method includes acidifying the steam condensate, preferably by hydrochloric acid, to reduce the pH to between about 7 and about 4.5 and then combining the acidified condensate with the brine. In a silica crystallizer stage in which flashed brine is contacted with a silica seed material to cause silica removal from the brine, the treated condensate is combined with the brine in a low pressure crystallizer upstream of brine clarification and reinjection stages.

Abstract: A fast Fourier transform (FFT) apparatus with data timing schedule decoupling is provided for obtaining the Fourier spectrum, f.sub.m, of a sequence of N data: S.sub.0, S.sub.1 . . . S.sub.N-1, derived from a time variable function, S.sub.t. The apparatus is operative for performing .alpha. sets of N/2 pairs of "butterfly" operations of the general form:A(x)'=A(x)+W.sub.(z) .multidot.A(y) andA(y)'=A(x)-W.sub.(z) .multidot.A(y),wherein A(x) and A(y) are data terms to be operated on and W.sub.(z) is a predetermined "pointer" into a corresponding matrix or phase angle library; .alpha. is determined by the relationship N=2.sup..alpha.. Comprising the apparatus are a first, A(x), A(y) data memory, a second, W.sub.(z) data memory, a multiplier accumulator (MAC) and an adder/subtractor.