This invention is directed to a process of generating silicon tetrafluoride (SiF/sub 4/) from aqueous solutions of hexafluorosilicic acid (H/sub 2/SiF/sub 6/), comprising reacting an aqueous solution of H/sub 2/SiF/sub 6/ with a concentrated aqueous salt solution to produce a precipitate, separating and drying the precipitate, and heating the precipitate in an inert atmosphere to decompose the precipitate producing SiF/sub 4/.

The invention is an improvement to an intruder-detection system of the kind where intruder-induced signals are transmitted through a medium whose conductance varies with certain climatic conditions. The improved system includes means coupled to the medium for converting the intruder-induced signals received therefrom to a first electrical signal. Means also are provided for generating a reference signal proportional to the climate-induced changes in the signal-conductance of the medium. Means are provided for generating, from the first electrical signal and the reference signal, an electrical output signal which is unaffected by the changes in signal-conductance. Means are provided to give warning when the output signal exceeds a selected value. In another aspect, the invention is a method for operating an intruder-detection system of the kind wherein an intrusion-generated signal transmitted through a detection medium is converted to a first electrical signal. The first electrical signal contains variations resulting from climate-induced changes in the medium. The method of the invention comprises generating an electrical reference signal proportional to the climate-induced changes in the medium; conditioning the first signal with the reference signal to produce an electrical output signal which is unaffected by the climate-induced changes in the medium; and impressing the resulting …

This invention provides an antenna arrangement for accurately measuring the magnetic permeability of earth formations. It provides a high-resolution coil array of a transmitting coil and six receiving coils to enable self-consistency checks for evaluating tight gas and oil-bearing strata. (DLC)

Novel substituted coumarin compounds and an improved method for their synthesis are disclosed. The preferred class of compounds are substituted at the 7-position. The method of synthesis comprises reacting a polyhydroxy benzene or a substituted phenol, with a ..beta..-alkoxy acrylic acid or nitrile, in the presence of a Lewis acid catalyst. By the inclusion of the catalyst in the reaction mixture, the reaction can be carried out under much milder experimental conditions and in increased yields. The method is also applicable to the preparation of substituted amino phenols.

An ultimate shutdown system is provided for termination of neutronic activity in a nuclear reactor. The shutdown system includes bead chains comprising spherical containers suspended on a flexible cable. The containers are comprised of mating hemispherical shells which provide a ruggedized enclosure for reactor poison material. The bead chains, normally suspended above the reactor core on storage spools, are released for downward travel upon command from an external reactor monitor. The chains are capable of horizontal movement, so as to flow around obstructions in the reactor during their downward motion.

Inductive storage pulse circuit device is disclosed which is capable of delivering a series of electrical pulses to a load in a sequential manner. Silicon controlled rectifiers as well as spark gap switches can be utilized in accordance with the present invention. A commutation switching array is utilized to produce a reverse current to turn-off the main opening switch. A commutation capacitor produces the reverse current and is initially charged to a predetermined voltage and subsequently charged in alternating directions by the inductive storage current.

Disclosed is a locking mechanism for an indexing spindle. A conventional spur gear having outwardly extending teeth is affixed to the spindle. Also included is a rotatably mounted camshaft whose axis is arranged in skewed relationship with the axis of the spindle. A disk-like wedge having opposing camming surfaces is eccentrically mounted on the camshaft. As the camshaft is rotated, the camming surfaces of the disk are interposed between adjacent gear teeth with a wiping action that wedges the disk between the gear teeth. A zero backlash engagement between disk and gear results, with the engagement having a high mechanical advantage so as to effectively lock the spindle against bi-directional rotation.

This disclosure relates generally to nondestructive testing for identifying structural characteristics of an object by scanned holographic techniques using a known source of radiation, such as electromagnetic or acoustical radiation. It is an object of this invention to provide an apparatus and method for synthetic aperture expansion in holographic imaging applications to construct fringe patterns capable of holographic reproduction where aperture restrictions in nondestructive testing applications would conventionally make such imaging techniques impossible. The apparatus and method result in the production of a sharply defined frontal image of structural characteristics which could not otherwise be imaged because they occur either near the surface of the object or are confined by geometry restricting aperture dimensions available for scanning purposes. The depth of the structural characteristic below the surface of the object can also be determined by the reconstruction parameters which produce the sharpest focus. Lateral resolution is established by simulated reduction in the radiation wavelength and may easily be an order of magnitude less than the electromagnetic wavelength in the material or 2 times the standard depth of penetration. Since the phase multiplication technique is performed on the detected data, the penetration depth available due to the longer wavelength signals applied …

The novel compounds 1-/sup 11/C-D-glucose, 1-/sup 11/C-D-mannose, 1-/sup 11/C-D-galactose, 2-/sup 11/C-D-glucose, 2-/sup 11/C-D-mannose and 2-/sup 11/C-D-galactose which can be used in nuclear medicine to monitor the metabolism of glucose and galactose can be rapidly prepared by reaction of the appropriate aldose substrate with an alkali metal /sup 11/C-labeled cyanide followed by reduction with a Raney alloy in formic acid.

A high efficiency, free electron laser is described utilizing a circular relativistic electron beam accelerator and a circular whispering mode optical waveguide for guiding optical energy in a circular path in the circular relativistic electron beam accelerator such that the circular relativistic electron beam and the optical energy are spatially contiguous in a resonant condition for free electron laser operation. Both a betatron and synchrotron are disclosed for use in the present invention. A free electron laser wiggler is disposed around the circular relativistic electron beam accelerator for generating a periodic magnetic field to transform energy from the circular relativistic electron beam to optical energy.

A method for doping semiconductor material and the semiconductor produced by the method are described. An interface is established between a solid electrolyte and a semiconductor to be doped. The electrolyte is chosen to be an ionic conductor of the selected impurity and the semiconductor material and electrolyte are jointly chosen so that any compound formed from the impurity and the semiconductor will have a free energy no lower than the electrolyte. A potential is then established across the interface so as to allow the impurity ions to diffuse into the semiconductor. In one embodiment the semiconductor and electrolyte may be heated so as to increase the diffusion coefficient.

Apparatus for forming and utilizing a sequence of electron beam segments, each of the same temporal length (substantially 15 nsec), with consecutive beams being separated by a constant time interval of the order of 3 nsec is described. The beam sequence is used for simultaneous inputs to a plurality of wiggler magnet systems that also accept the laser beams to be amplified by interaction with the co-propagating electron beams. The electron beams are arranged substantially in a circle to allow proper distribution of and simultaneous switching out of the beam segments to their respective wiggler magnets.

A method for laser beam amplification by means of free electron laser techniques is described. With wiggler magnetic field strength B/sub w/ and wavelength lambda/sub w/ = 2..pi../k/sub w/ regarded as variable parameters, the method(s) impose conditions such as substantial constancy of B/sub w//k/sub w/ or k/sub w/ or B/sub w/ and k/sub w/ (alternating), coupled with a choice of either constant resonant phase angle or programmed phase space bucket area.

A method for real-time elemental analysis using laser-induced breakdown of the material under investigation and spectroscopic analysis of the light emitted from the plasma consequently formed is described. By delaying the observation of the emitted radiation, the unwanted background continuum and line spectra from excited ionic species can be rendered unimportant relative to the excited atomic line spectra, thereby producing sharp, well-defined characteristic identifying atomic spectral features. These features provide the indicia for detailed elemental analyses of substances. The method is quite general in that it applies to gases, surfaces, and particulates entrained in gases. It requires no electrodes and can excite atomic species like fluorine and chlorine which are difficult to observe by more conventional analytical procedures.

A method for simultaneous amplification of laser beams with a sequence of freqeuncies in a single pass, using a relativistic beam of electrons grouped in a sequence of energies corresponding to the sequence of laser beam frequencies is described. The method allows electrons to pass from one potential well or bucket to another adjacent bucket, thus increasing efficiency of trapping and energy conversion.

Method and apparatus for amplification of a laser pulse in a free-electron-laser amplifier where the laser pulse duration may be a small fraction of the electron-beam-pulse duration used for amplification. An electron-beam pulse is passed through a first wiggler magnet and a short laser pulse to be amplified is passed through the same wiggler so that only the energy of the last fraction, f, (f < 1) of the electron-beam pulse is consumed in amplifying the laser pulse. After suitable delay of the electron beam, the process is repeated in a second wiggler magnet, a third, ..., where substantially the same fraction f of the remainder of the electron-beam pulse is consumed in amplification of the given short laser pulse in each wiggler magnet region until the useful electron-beam energy is substantially completely consumed by amplification of the laser pulse.

A method of preparing a porous cathode structure for use in a molten carbonate fuel cell begins by providing a porous integral plaque of sintered nickel oxide particles. The nickel oxide plaque can be obtained by oxidizing a sintered plaque of nickel metal or by compacting and sintering finely divided nickel oxide particles to the desired pore structure. The porous sintered nickel oxide plaque is contacted with a lithium salt for a sufficient time to lithiate the nickel oxide structure and thus enhance its electronic conductivity. The lithiation can be carried out either within an operating fuel cell or prior to assembling the plaque as a cathode within the fuel cell.

Improved means and process for producing ethanol by fermentation are provided. Another object of the invention is to produce ethanol in a continuous-flow process by means of a biological catalyst that can be retained in a continuous-flow reactor vessel without being bonded to or held within a support material. An additional object of the invention is to provide a fermentation reactor vessel wherein disturbance of the desirable plug flow of sugar solution is minimized. These objects are attained by the preferred apparatus and process of the invention which utilize a newly-discovered flocculent strain of Zymomonas mobilis for converting sugar to ethanol in a continuous flow-type reactor vessel. The flow rate of a sugar-containing solution through a column containing the floc-forming strain of Z. mobilis is adjusted so that a sufficient conversion of sugar to ethanol is achieved in the column and the flocculent Z. mobilis is not washed away in effluent from the column. Carbon dioxide gas generated by the fermentation process is vented from a plurality of points spaced along an inclined column in which the process is conducted, thus minimizing disturbance of the plug flow of liquid by this gas.

A cutting apparatus includes a support table mounted for movement toward and away from a workpiece and carrying a mirror which directs a cutting laser beam onto the workpiece. A carrier is rotatably and pivotally mounted on the support table between the mirror and workpiece and supports a conduit discharging gas toward the point of impingement of the laser beam on the workpiece. Means are provided for rotating the carrier relative to the support table to place the gas discharging conduit in the proper positions for cuts made in different directions on the workpiece.

The present invention is directed to a cutting fluid for machining fissionable material. The cutting fluid is formed of glycol, water and a boron compound in an adequate concentration for effective neutron attenuation so as to inhibit criticality incidents during machining.

The photosensitivity of lead lanthanum zirconate titanate (PLZT) ceramic material used in high resolution, high contrast, and nonvolatile photoferroelectric image storage and display devices is enhanced significantly by positive ion implantation of the PLZT near its surface. Implanted ions include H/sup +/, He/sup +/, Ne/sup +/, Ar/sup +/, as well as chemically reactive ions from Fe, Cr, and Al. The positive ion implantation advantageously serves to shift the absorption characteristics of the PLZT material from near-uv light to visible light. As a result, photosensitivity enhancement is such that the positive ion implanted PLZT plate is sensitive even to sunlight and conventional room lighting, such as fluorescent and incandescent light sources. The method disclosed includes exposing the PLZT plate to the positive ions at sufficient density, from 1 x 10/sup 12/ to 1 x 10/sup 17/, and with sufficient energy, from 100 to 500 keV, to provide photosensitivity enhancement. The PLZT material may have a lanthanum content ranging from 5 to 10%, a lead zirconate content of 62 to 70 mole %, and a lead titanate content of 38 to 30%. The ions are implanted at a depth of 0.1 to 2 microns below the surface of the PLZT plate.

This invention is a novel portable charger for dosimeters of the electrometer type. The charger does not require batteries or piezoelectric crystals and is of rugged construction. In a preferred embodiment, the charge includes a housing which carries means for mounting a dosimeter to be charged. The housing also includes contact means for impressing a charging voltage across the mounted dosimeter. Also, the housing carries a trigger for operating a charging system mounted in the housing. The charging system includes a magnetic loop including a permanent magnet for establishing a magnetic field through the loop. A segment of the loop is coupled to the trigger for movement thereby to positions opening and closing the loop. A coil inductively coupled with the loop generates coil-generated voltage pulses when the trigger is operated to open and close the loop. The charging system includes an electrical circuit for impressing voltage pulses from the coil across a capacitor for integrating the pulses and applying the resulting integrated voltage across the above-mentioned contact means for charging the dosimeter.

In one form of the invention, hydrogen is produced by providing a reactor containing a body of water. The water contains photolytic material, i.e., photoactive material containing a hydrogen-catalyst. The interior of the reactor is isolated from atmosphere and includes a volume for receiving gases evolved from the body of water. The photolytic material is exposed to light to effect photosynthetic splitting of the water into gaseous hydrogen and oxygen. The gas-receiving volume is continuously evacuated by pumping to promote evolution of gaseous hydrogen and oxygen into that volume and to withdraw them therefrom. In another form of the invention, separation of the hydrogen and oxygen is effected by selectively diffusing the hydrogen through a heated semipermeable membrane in a separation zone while maintaining across the zone a magnetic field gradient biasing the oxygen away from the membrane. In a third form of the invention, the withdrawn gas is contacted with a membrane blocking flow of water vapor to the region for effecting recovery of the hydrogen. In a fourth embodiment, the invention comprises a process for selectively recovering hydrogen from a gas mixture comprising hydrogen and oxygen. The process is conducted in a separation zone and comprises contacting the …

Molten metal removed from a workpiece in a laser cutting operation is blown away from the cutting point by a gas jet and collected on an electromagnet. The laser cutting is used to separate the castings of spent fuel rods from the fuel-containing elements therein.