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Utilization of the Surface Tension of Liquid Metals in Making High-Vacuum Seals

Description: Abstract: "The free energy (surface tension) of a liquid film can withstand atmospheric pressure across a maximum theoretical gap of 10-(-3) cm between solids if the liquid wets and bridges the sides of the gap continuously. The eutectic alloy of Ga, lm and Sm is used for this purpose. This alloy is molten at room temperature with surface tension > 500 dynes/cm, vapor pressure < 10-(-8) cm at 500 C and excellent wetting properties. This alloy can be utilized in valves, motion seals, flanged joints and for electrical contacts mounted in any position. Using ultrasonic soldering techniques without heat or flux this alloy is readily wetted on W, Mo, Ta, pyrex, quartz and certain ceramics. These materials will withstand the corrosive action of this alloy at at least 400 C. Some de-wetting has been observed with only the nonmetals at high temperatures. This de-wetting may be due to thermal decomposition of gallium oxide. Stainless steel is easily wetted, but is attacked at temperatures above 300 C. Copper and brass are attacked at room temperature."
Date: August 30, 1957
Creator: Milleron, Norman
Partner: UNT Libraries Government Documents Department

A balanced-pressure sliding seal used for transfer of pressurized air between stationary and rotating parts

Description: A combination sliding-ring and pressure-balancing seal capable of transferring pressurize air from stationary to rotating parts was developed and experimentally investigated at sliding velocities and cooling-air pressures up to 10,000 feet per minute and 38.3 pounds per square inch absolute, respectively. Leakage of cooling air was completely eliminated with an expenditure of balance air less than one-fourth the leakage loss of air from labyrinth seals under the same conditions. Additional cooling of the carbon-base seal rings was required, and the maximum wear rate on the rings was about 0.0005 inch per hour.
Date: January 9, 1957
Creator: Curren, Arthur N. & Cochran, Reeves P.
Partner: UNT Libraries Government Documents Department

Wear of typical carbon-base sliding seal materials at temperatures to 700 degrees F

Description: Report presenting wear and friction studies to show the effects on performance of temperature, type of mating material, and minor composition changes in typical carbon seal materials. Most data were obtained at a surface speed of 10,000 feet per minute, a load of 1000 grams on a 3/16-inch-radius specimen, and temperatures up to 700 degrees Fahrenheit. Wear of carbon seal materials increased rapidly with high temperatures. The effect of temperature on wear was reduced by using chromium-plated steel as the mating surface rather than stainless or tool steel.
Date: February 1956
Creator: Johnson, Robert L.; Swikert, Max A. & Bailey, John M.
Partner: UNT Libraries Government Documents Department

A Compilation of Historical Monk Seal, Monachus schauinslandi, Counts

Description: The following document is meant to facilitate an analysis and review of historical counts of the Hawaiian monk seal. Provided here are tables ordered on an island-by-island or atoll-by-atoll basis, beginning in the early 1800s and on through the 1980s.
Date: September 1992
Creator: Hiruki, Lisa M. & Ragen, Timothy J.
Partner: UNT Libraries Government Documents Department

Fluidtight Seal for a Container

Description: A fluidtight seal for a container is formed by abutting a metal ring with a step machined in a convexo-concave container closure device and inserting this assembly into an open end of the container. Under compressive force, the closure device deforms causing the metal ring to pivot about the step on the closure device and interact with symmetrically tapered inner walls of the container to form a fluidtight seal between the container and the closure device. The compressive force is then withdrawn without affecting the fluidtight characteristic of the seal. A destructive force against the container closure device is necessary to destroy the fluidtight seal.
Date: March 31, 1999
Creator: Morrison, Edward F.
Partner: UNT Libraries Government Documents Department

Hawaiian Monk Seal Reproduction and Injuries on Lianski Island, 1982

Description: Abstract: data on the Hawaiian monk seal, Monachus schnauinslandi, including pup production, pupping locations, and injuries at Lisianski Island in 1982 are presented. Twenty-eight pups were born, of which 26 survived to weaning. Of the observed births, 75% occurred on the east side of the island. Average nursing period for 14 mother-pup pairs was 37.4 days. One exchange of pups was observed. Ten seals were injured while personnel were present on the island. Four of these injuries were attributable to attacks by adult male seals.
Date: July 1986
Creator: Johanos, Thea C. & Henderson, John R.
Partner: UNT Libraries Government Documents Department

Estimation of Hawaiian Monk Seal Corruption in Relation to Ecosystem Biomass and Overlap with Fisheries in the Main Hawaiian Islands

Description: This report analyzes the possible effects of the rehabilitation of Hawaiian monk seals and how their increase in numbers will affect the ecosystem and our fisheries. The document takes into account conclusions that overestimate potential monk seal impacts, and underestimate potential impacts of human extraction on monk seals.
Date: August 2013
Creator: Sprague, Rachel; Littnan, Charles & Walters, Jeffrey
Partner: UNT Libraries Government Documents Department

Remote Plastic Bag Passout Unit for High-Level Radiochemical Operations

Description: A system is designed for making remote sealed-bag passouts from a multicurie-level chemistry processing enclosure. The polyethylene bags are changed remotely without exposing contaminated surfaces while always maintaining a low leak rate seal. The system employs an interchange box (passout box) attached to the chemistry enclosure. Integrated with the box is a hydraulically operated jack that raises and lowers the bags, and a welder-cutter for sealing them. A single master-slave manipulator teamed with the above units handles all operations. (auth)
Date: August 1, 1961
Creator: Fleischer, E. S.; Parsons, T. C. & Howe, P. W.
Partner: UNT Libraries Government Documents Department

Censuses and Interatoll Movements of the Hawaiian Monk Seal on Laysan Island, 1985

Description: Abstract: Research on the Laysan Island population of the endangered Hawaiian monk seal, Monachus schauinslandi, was conducted from 2 march to 30 November 1985. census totals excluding pups ranged from 76 to 147, an average increase of nearly 20 animals from the 1984 census results. Overall monthly haul-out distribution for all seals showed highest use in the north ecological unit followed by the west unit. Relatively few animals hauled out in the eastern and southern portions of the island. Interatoll movement of nine seals was documented, resulting in a net increase of three animals to the Laysan Island population.
Date: September 1989
Creator: Becker, Brenda L.; Morrow, Robert J. & Leialoha, Julia K.
Partner: UNT Libraries Government Documents Department

The Hawaiian Monk Seal on the Laysan Island: 1982

Description: This is a report on a 3.5 month observational study of the endangered Hawaiian monk seal that took place on the Laysan Island. The total recorded counts ranged from 66-119 and averaged to 90 seals, five of which died in the few months, nine injured.
Date: April 1984
Creator: Alcorn, Doris J.
Partner: UNT Libraries Government Documents Department

Proceedings of the Second International Conference on Marine Debris: [Session 2]

Description: Compilation of papers presented during the second session of the Second International Conference on Marine Debris, held by the National Oceanic and Atmospheric Administration in Hawaii, April 1989. This session includes 116 papers describing the effects of net fragment entanglement on northern fur seals, particularly the swimming behavior of entangled and nonentangled seals.
Date: 1990
Creator: Shomura, R. S. & Godfrey, M. L.
Partner: UNT Libraries Government Documents Department


Description: >A centrifugal pump performed adequately at a flow rate of 7200 gpm of 945 gas-cooled F sodium at a 150-ft head. A two-region freeze seal was developed and used successfully as a shaft seal on this pump. The results indicate that this pump could perform satisfactorily in the Hallam Power Reactor. (auth)
Date: November 1, 1960
Creator: Atz, R.W.
Partner: UNT Libraries Government Documents Department


Description: Lip type, oil labyrinth gas shaft seals were tested for use on Hallam Power Reactor sodium pumps with a 5-in.diameter rotating shaft. The seals were not recommended for use owing to excess helium leakage and short life. (C.J.G.)
Date: June 30, 1958
Creator: Admire, B.W. & Nayor, F.S.
Partner: UNT Libraries Government Documents Department

Cylinder Seal with Imprint

Description: The cylinder seal displayed to the left of a clay impression from seal. To the far right a photograh of the impression is included.
Access: This item is restricted to UNT Community Members. Login required if off-campus.
Date: unknown
Partner: UNT College of Visual Arts + Design

A Robotic Pinch-Off System for the Sealing of Neutron Tube Assemblies

Description: The process of manufacturing the MC4277 Neutron Tube requires the evacuation of the device through a 4.76 mm (.1875 in.) OD copper tube. Eight tubes are simultaneously evacuated and then baked out. When the process is completed, the tubes must be separated from the system without compromising the ultra-high vacuum in the tube and the system. Previously, a manual pinch-off tool was used. This procedure required up to 3 operators with a high probability of creating defective seals or destroyed tubes. Two new identical robotic systems were built to allow a single operator to consistently produce good tubes with perfect seals. These systems have the added capability of partially pinching off tubes at jaw displacements repeatable to *0.05 mm (kO.002 in.). Both systems have operated flawlessly since their installation in January and March, 1998. A detailed description of these systems is given in this report.
Date: January 1, 1999
Creator: Ney, R.J. & Schmale, D.T.
Partner: UNT Libraries Government Documents Department


Description: This report provides a concise summary of the information collected and analyzed regarding the leak characteristics which define them as applicable candidates for pressure activated sealant technology. This information covers Office of Pipeline Safety reported incidents from 1985 to 1997 and was collected from existing data sources as well as operator and service company input.
Date: January 1, 2004
Creator: Romano, Michael A.
Partner: UNT Libraries Government Documents Department

Novel tamper-indicating protective devices

Description: Several novel tamper-indicating devices, originally developed under DOE auspices for arms control applications, might be useful in nonproliferation. Some devices that have reached the laboratory prototype stage could provide specialized alternatives to established seals. As locks and cables, the following might be useful: (1) a brittle ceramic lock--impervious to toxic, radiation, and thermal extremes--interrogated for identification and continuity by ultrasonic means, (2) a flexible ceramic-fiber seal that also tolerates severe environments, (3) an ultrasonic smart-material strip seal, and (4) an RF-resonant coaxial cable, verified by radio frequency and microwave signals. To validate the identity of secured surfaces, joints, welds, and fasteners--two techniques are applicable: (1) the scanning electron microscope, which examines three- dimensional micron-level topography, and (2) the plastic-casting fingerprint, a simple low-cost technique, analogous to human fingerprinting. The techniques mentioned above have one or more of the potential advantages of low cost, immediate availability, security for large-area enclosures, application to hazardous environments, usability in the FSU, or suitability for covert use.
Date: July 1, 1995
Creator: DeVolpi, A.
Partner: UNT Libraries Government Documents Department

Hinge Moments of Sealed-Internal-Balance Arrangements for Control Surfaces 2: Experimental Investigation of Fabric Seals in the Presence of a Thin-Plate Overhang

Description: Report presenting tests in a seal test chamber to determine the hinge moments contributed by the fabric seal in an internal-balance arrangement employing a thin-plate overhang. The tests were performed with various widths of fabric sealing various widths of flap-nose gap, with a horizontal, a vertical, and a circular type of wing structure forward of the balance, and with various heights of balance chamber. Results regarding seal-profile photographs, desired seal-moment characteristics, experimental seal-moment characteristics, effect of the balance configuration on the seal-moment characteristics, comparison of analytical and experimental seal-moment characteristics, computation of seal-moment characteristics by the approximate method, and application of the data are provided.
Date: August 1945
Creator: Fischel, Jack
Partner: UNT Libraries Government Documents Department

Hawaiian Monk Seal and Green Turtle Research on Lisianski Island, 1986

Description: This is a report where the Hawaiian monk seal and the green turtle were studied intermittently on Lisianski Island throughout the summer of 1986. This observational study includes injuries, deaths, reproductions, entanglements and tagging of seals and green turtles.
Date: August 1988
Creator: Westlake, Robin L. & Siepmann, Paul J.
Partner: UNT Libraries Government Documents Department

Recommended Recovery Actions for the Hawaiian Monk Seal Population at Midway Island

Description: The following document was made as part of a workshop for members of the Hawaiian Monk Seal Recovery Team to develop recommendations for recovery actions of the Hawaiian monk seal. The document provides extensive background knowledge on observational studies done in the past years over their endangerment and the causes of it.
Date: May 1998
Creator: Gilmartin, William G. & Antonelis, George A.
Partner: UNT Libraries Government Documents Department