Abstract: A thermosyphon for removing heat from a permafrost foundation, the invent can be installed in a frozen foundation with an evaporator section disposed either horizontally or with a negative (up) slope, thereby allowing the evaporator section of the thermosyphon to be buried in a more shallow location of the foundation than is possible with conventional thermosyphon devices. The thermosyphon of the invention has a condensate collection ring near the lowest point but higher than any point in the evaporator of a condenser section which extends above the permafrost foundation and into heat exchange contact with low-temperature above-ground air. Condensate formed in the condenser section by heat exchange with the air is collected in the collection ring and ducted through a condensate return tube to a desirable location within the evaporator section, usually the extreme distal end thereof.

Abstract: An elongated anode, comprising an electrically conductive ceramic material coated on a valve metal substrate, is secured in a correspondingly elongated groove which extends longitudinally in a shield of electrically non-conductive material. The shield has a convex outer surface when viewed in a plane perpendicular to its longitudinal axis. The shield can be a longitudinal segment of a cylindrical thermoplastic pipe containing spirally wound reinforcing filaments. The interior space of the annular segment can be filled with a resilient material to provide a cushion.

Abstract: An ice auger extractor for retrieving augers or similar devices from a bore ole includes a cylindrical housing and a spring-biased locking cam positioned in a vertically extending recess. The recess is substantially L-shaped and extends in a portion of periphery of the housing. The cam includes a serrated edge which secures the auger rod within the bore of the housing before its retrieval. A bore adapter may be connected with the housing and includes a substantially L-shaped snagging hook for centering the auger rod in the situation where the free end of the auger rod is embedded in the wall of bore hole. The housing and the bore adapter both include frusto-conical surfaces for guiding the auger rod into the housing.

Abstract: A reticle plate provided with a reticle and three concentric circles of ving diameter and methods of use thereof, the invention allows a user to establish a north-oriented or south-oriented line by alignment of selected circumpolar stars with the circles. The circles are located on the reticle plate in positions determined by angles which exist between the celestial north (or south) pole and the particular low-magnitude circumpolar stars chosen as sighting points, the radii of the circles being directly proportional to the objective lens focal length of the theodolite or optical instrument within which the plate is used. A first method of the invention allows unambiguous location of the north or south pole by alignment of each of three selected stars with one each of the three circles. A second method provides data to a user sufficient to locate the pole by alignment of innermost and outermost circles respectively with one each of two of the selected stars.

Abstract: A method and apparatus for cutting ice core specimens from a block or sheet f ice, the invention provides swivel cutter elements mounted on the cutter head of an ice coring auger. The swivel cutters each swing into an outwardly extending position against the force of a retracting spring on contact with ice to be cut, the outward movement of the cutters being due to reaction forces acting on the cutters caused by contact with the ice. A core specimen is thereby cut to a desired depth in the ice and advancement of the coring auger is then discontinued although rotation of the auger is continued. While auger rotation continues, each swivel cutter moves inwardly under the force of the retracting spring once the reactive forces caused by advancement of the auger into the ice no longer act on the cutters.

Abstract: A rotary valve assembly is disclosed for regulating the flow through two ts to control the filling and emptying of a lock. The valve assembly includes a plurality of planar elements, rotatable about a vertical axis within a cylindrical housing, and disposed at predefined angles as viewed in a horizontal plane, determined by the angles of intersection with the housing of a plurality of fluid conduits. Controlled rotation of the valve positions the planar elements relative to the fluid conduits, to direct flow from a source conduit into a lock chamber to fill it with water, to direct flow from the chamber to empty the lock, or to prevent flow altogether.

Abstract: A method is disclosed for calibrating an optical measuring system (14, 18, 0, 22) of the type which reproducibly projects a beam of light (16) over an extended period of time. The deviation between an incident beam and a rerflected beam is measured on both sides (30, 32) of a parallel-sided calibration mirror (28).

Abstract: A system for detecting and monitoring blast noise, the invention provides ncentrically arranged cylindrical windscreens having a pair of vertically spaced microphones mounted centrally therein, the windscreens acting to reduce interference from wind-generated pseudosound yet being acoustically transparent so as not to interfere with the reception of acoustical data incident on the microphones. The present system also includes a signal processing subsystem which receives the output of the respective microphones for analysis.

Abstract: Illustrative embodiments of the invention are directed to a technique for raising and lowering large tainter gates. Typically, two groups of lifting apertures are formed in the gate. A lifting mechanism, resiliently mounted on the tainter gate pier, inserts a movable pin into an aperture in one of the two groups and draws the gate upwardly. A stationary pin on the lifting mechanism then is inserted into an aperture in the other of the two groups to absorb the gate load while the movable pin is withdrawn and moved to a new aperture in order to continue the step-wise lifting process.To lower a gate, an essentially reverse procedure is followed.

Abstract: Washing device of the gun type intended to be held by two hands. Designed en in operation to have a generally linear flow path for liquid to deliver the maximum volume of liquid at a given water pressure. Especially useful for washing mud from the tracks of military vehicles.

Abstract: A system and method for relieving frost-heaving stresses in a pipeline for ransporting a product at a temperature less than 32.degree. F. where said pipeline passes through frost-susceptible ground in a trench beneath the ground surface. Bedding supports the pipeline in the trench with its top substantially below the surface of the ground. A pair of relatively thin, elongated soil separators are installed in the trench, one along each side of the pipeline in parallel relation to the longitudinal axis of the pipeline. Each separator has a transverse width extending vertically upward substantially beyond the top of the pipeline and into backfill soil above the pipeline. Padding supports a lower edge of the shear separators adjacent to the pipeline and the separators each have an upper edge located substantially beyond this padding and beyond the top of the pipeline.

Abstract: Method and means for determining the corrosion status of a coated undergrd metallic object without the necessity of excavation. An electrical charge is produced on an area of the pipe, and the rate at which the charge decays is measured. The degree of corrosion of the object is measured as a function of the rate of decay of the charge and the area charged.

Abstract: A method for digitally constructing variable width cartographic lines, the invention provides an algorithm for generating symbolized lines using multiply-stroked centerline data. The algorithm allows generation of software which utilizes trigonometric functions and which can be implemented in applications using vector data with vector or raster plotters. The algorithm further accounts for basic cartographic principles, existing algorithm characteristics and hardware constraints imposed by specific output devices.

Abstract: A method and apparatus for topographic feature extraction by masking a video signal representation of an optical image using a two-dimension Walsh function is disclosed. The optical energy of an image is converted into a video signal. A Walsh function signal in accordance with a two-dimension Walsh is generated. The video signal is multiplied with the Walsh function signal to produce a Walsh transform coefficients signal indicative of the decomposed spectral components of the image. The method and apparatus can further include providing selected topographical feature signals in accordance with the Walsh transform coefficients of selected topographic features. A selected topographical feature can be detected by comparing the Walsh transform coefficients signal with the selected topographical feature signals. The Walsh transform coefficients signal is unique to the selected topographical feature being detected.

Abstract: A method and apparatus for directly measuring the hydraulic conductivity of porous materials at various degrees of saturation, the invention involves determination of the rate of rotation under dynamic equilibrium of concentric cylinders having a partially saturated porous material disposed in an annular space between the concentric cylinders, the rate of rotation being directly related to the hydraulic conductivity of the material. The hydraulic conductivity of the material can thus be determined without the need for measuring fluid discharge and piezometric head gradient as is necessary in prior art determination of hydraulic conductivity.

Abstract: A fire detection system using optical fibers to transmit flame signals from a plurality of remote monitoring stations to a central detection and analysis station, the invention comprises a network of optical fibers which connect the monitoring stations to the central detection station for the purpose of transmitting incident analog optical, infrared and ultraviolet spectra to the central station for detection of fire conditions. The central detection and analysis station preferably includes a rotary scanner which scans each of the optical fibers, light from the fibers being dispersed by a prism associated with the scanner to allow detection of the various spectral components of the dispersed light by light sensitive semiconductors. The detected spectral components are then compared to known fire signal signatures which include flicker rate and spectral content information.

Abstract: A method and apparatus for determining the bulk thermal conductivity of a particular material includes the steps of embedding a thermistor in the material for which the bulk thermal conductivity is to be measured, applying a small current from a constant current source to the thermistor, mathematically determining the temperature of the material, applying a larger current to the thermistor until a steady state thermal condition is obtained, calculating the thermistor resistance, and finally calculating the thermal conductivity of the material according to the formula ##STR1## where I is the large current, R is the thermistor resistance when heated by the larger current, r.sub.1 is the radius of the thermistor glass bead, T.sub.1 is the surface temperature of the glass envelope of the thermistor and T.sub.2 is the homogenous temperature of material whose bulk thermal conductivity is to be measured.

Abstract: An apparatus for performing an incoherent optical Fourier transform inclu a source of incoherent light, means for generating and phase modulating a first zone plate, a second zone plate, means for detecting incoherent light processed by the apparatus, and means for filtering the output signal, thereby discriminating between the Fourier transform signal and background constant or bias signals. A method for performing incoherent optical Fourier transform is also disclosed.

Abstract: An energy-conserving roof structure for use in construction of low-slope fs comprising two layers of permeable insulation and a layer of non-permeable insulation sandwiched between a pair of water vapor impermeable layers. The non-permeable insulation layer is placed to provide channels through which water will flow to roof drains. Closeable vents are provided adjacent the roof drains for venting water and water vapor. When the vents are closed the water vapor impermeable layers form a water vapor impermeable envelope around the insulation layers. Auxiliary vents are provided for venting the insulation layers to the ambient atmosphere at locations remote from the roof drains. By opening the vents when low-humidity conditions are present and closing the vents when high-humidity conditions are present moisture in the insulation layer is kept to a minimum, thereby maintaining the insulation layers at their highest thermal efficiency.

Abstract: Improved constant and variable force tensioning devices are made possible by utilizing atmospheric pressure to provide the restoring force. In one embodiment, a sealed and substantially evacuated canister is provided with a rigid actuating rod which can be partially withdrawn through an opening in one end of the canister against the constant restoring force exerted by atmospheric pressure. In another embodiment, the rigid actuator rod is replaced by a long flexible rod or cable which is capable of collapsing or folding upon itself within the canister, thereby providing the constant force device with a longer stroke. In a further embodiment, the actuator rod terminates in a rolling diaphragm seal which seals off only a portion of the canister interior, eliminating the need for a sliding vacuum seal at the point where the actuator rod protrudes from the canister.