Abstract: The general purpose of the invention is to develop a high specific energy nickel electrode for a nickel based battery system. The invention discloses a method of producing a lightweight nickel electrode which can be cycled to deep depths of discharge (i.e., 40% or greater of electrode capacity). These deep depths of discharge can be accomplished by depositing the required amount of nickel hydroxide active material into a lightweight nickel fiber substrate.
Type:
Grant
Filed:
October 27, 1994
Date of Patent:
July 24, 2001
Assignee:
The United States of America as represented by the
Adminstrator of the National Aeronautics and Space
Adminstration
Abstract: A particulate reinforced NiAl-AlN composite alloy has a NiAl matrix and greater than about 13 volume percent fine particles of AlN within the matrix. The particles preferably have a diameter from about 15 nanometers to about 50 nanometers. The particulate reinforced NiAl-AlN composite alloy may be prepared by cryomilling prealloyed NiAl in liquid nitrogen using grinding media having a diameter of from about 2 mm to about 6 mm at an impeller speed of from about 450 RPM to about 800 RPM. The cryomilling may be done for a duration of from about 4 hours to about 20 hours to obtain a cryomilled powder. The cryomilled powder may be consolidated to form the particulate reinforced NiAl-AlN composite alloy. The particulate reinforced alloy can further include a toughening alloy. The toughening alloy may include NiCrAlY, FeCrAY and FeAl.
Type:
Grant
Filed:
May 5, 1994
Date of Patent:
June 3, 1997
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Inventors:
Mohan G. Hebsur, John D. Whittenberger, Carl E. Lowell
Abstract: A hydrogen sensitive metal alloy contains palladium and titanium to provide a larger change in electrical resistance when exposed to the presence of hydrogen. The alloy can be used for improved hydrogen detection.
Type:
Grant
Filed:
December 30, 1994
Date of Patent:
May 28, 1996
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: A silicon-base ceramic substrate is provided with a mullite chemical barrier/thermal barrier coating uniformly bonded to a surface. The coating is substantially free of amorphous mullite.
Type:
Grant
Filed:
December 20, 1993
Date of Patent:
March 5, 1996
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Inventors:
Kang N. Lee, Robert A. Miller, Nathan S. Jacobson
Abstract: A pest resistant molybdenum disilicide composition is provided for use in high temperature structural applications. The composition includes molybdenum disilicide and silicon nitride and can be used to prepare improved reinforced composites.
Type:
Grant
Filed:
April 7, 1993
Date of Patent:
July 4, 1995
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: Digital data coders/decoders are used extensively in video transmission. A digitally encoded video signal is separated into subbands. Separating the video into subbands allows transmission at low data rates. Once the data is separated into these subbands it can be coded and then decoded by statistical coders such as the Lempel-Ziv based coder.
Type:
Grant
Filed:
March 11, 1993
Date of Patent:
May 2, 1995
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: The use of guanidine salts of organic fatty acids (guanidine soaps) as vehicles and binders for coating substrate surfaces is disclosed. Being completely organic, the guanidine soaps can be burned off leaving no undesirable residue. Of special interest is the use of guanidine 2-ethyl hexanoate as the vehicle and binder for coating problematic surfaces such as in coating alumina fibers with platinum or zirconia. For this application the guanidine soap is used as a melt. For other applications the guanidine soap may be used in a solution with a variety of solvents, the solution containing chlorometalates or powdered metals, refractories or ceramics.
Type:
Grant
Filed:
June 25, 1993
Date of Patent:
March 7, 1995
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Inventors:
Warren H. Philipp, Lisa C. Weitch, Martha H. Jaskowiak
Abstract: The present invention generally relates to providing an improved jet mixer noise suppressor for high speed jets that rapidly mixes high speed air flow with a lower speed air flow, and more particularly, relates to an improved jet mixer noise suppressor that uses feedback of acoustic waves produced by the interaction of sheer flow instability waves with an obstacle downstream of the jet nozzle.
Type:
Grant
Filed:
February 10, 1994
Date of Patent:
February 28, 1995
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: A silicon-base ceramic substrate is provided with a mullite coating by flame-spraying heated crystalline mullite powders onto a substrate that is preheated to a temperature in excess of 800.degree. C. The mullite immediately crystallizes as it solidifies.
Type:
Grant
Filed:
March 15, 1993
Date of Patent:
February 21, 1995
Assignee:
The United States of America as represented by the National Aeronautics and Space Administration
Inventors:
Kang N. Lee, Robert A. Miller, Nathan S. Jacobson
Abstract: A SrO-Al.sub.2 O.sub.3 -2SrO.sub.2 (SAS) glass ceramic matrix is reinforced with CVD SiC continuous fibers. This material is prepared by casting a slurry of SAS glass powder into tapes. Mats of continuous CVD-SiC fibers are alternately stacked with the matrix tapes.This tape-mat stack is warm-pressed to produce a "green" composite. Organic constituents are burned out of the "green" composite, and the remaining interim material is hot pressed.
Type:
Grant
Filed:
September 16, 1993
Date of Patent:
February 14, 1995
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: An ion exchange polymer comprised of an alkali metal or alkaline earth metal salt of a poly(carboxylic acid) in a poly(vinyl acetal) matrix is described. The polymer is made by treating a mixture made of poly(vinyl alcohol) and poly(acrylic acid) with a suitable aldehyde and an acid catalyst to cause acetalization with some cross-linking. The material is then subjected to an alkaline aqueous solution of an alkali metal salt or an alkali earth metal salt. All of the film forming and cross-linking steps can be carried out simultaneously, if desired.
Type:
Grant
Filed:
June 21, 1993
Date of Patent:
December 6, 1994
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Inventors:
Warren H. Philipp, Kenneth W. Street, Jr.
Abstract: Service equipment 10 for use in hostile environments includes a detachable service unit 20 secured to a stationary service unit 50 as shown in FIG. 1. The detachable service unit includes a housing 28 with an exterior plate 22, a power control interface 16 for connection to an exterior power source 48, locating pins 30a-30d located in said exterior plate, an electrical connector 40 in the exterior plate electrically coupled to said power control interface, and a pair of clamping receptacles 24 and 25 formed in the exterior plate and located on adjacent opposite edges of the exterior plate as shown in FIGS. 4A and 4B. The stationary unit includes an electrical connector 46 for connection to the electrical connector of the detachable service unit, a clamping apparatus 60 for clamping and unclamping the detachable service unit from the stationary unit, a base clamp assembly 120 shown in FIG. 5A for mounting the clamping apparatus onto the stationary unit, and locating pin holes 51 shown in FIG.
Type:
Grant
Filed:
July 26, 1993
Date of Patent:
November 22, 1994
Assignee:
The United States of America, as represented by the Administrator National Aeronautics and Space Administration
Abstract: The present invention discloses a method of detecting and locating current imbalances such as ground faults in multiwire systems using the Faraday effect. As an example, for 2-wire or 3-wire (1 ground wire) electrical systems, light is transmitted along an optical path which is exposed to magnetic fields produced by currents flowing in the hot and neutral wires. The rotations produced by these two magnetic fields cancel each other, therefore light on the optical path does not read the effect of either. However, when a ground fault occurs, the optical path is exposed to a net Faraday effect rotation due to the current imbalance thereby exposing the ground fault.
Type:
Grant
Filed:
January 21, 1993
Date of Patent:
November 15, 1994
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Inventors:
Richard L. Patterson, Allen H. Rose, Ronald C. Cull
Abstract: This invention is a method for the controlled growth of single-crystal semiconductor-device-quality films of SiC polytypes on vicinal (0001) SiC wafers with low tilt angles. Both homoepitaxial and heteroepitaxial SiC films can be produced on the same wafer. In particular, 3C-SiC and 6H-SiC films can be produced within selected areas of the same 6H-SiC wafer.
Type:
Grant
Filed:
November 9, 1992
Date of Patent:
November 15, 1994
Assignee:
The United States of America as represented by the United States National Aeronautics and Space Administration
Abstract: The apparatus disclosed in the present invention measures the force at which a fiber resist the motion of an indenter driven at constant speed. This apparatus conducts these test in a vacuum of about 10.sup.-6 tort and at temperatures up to 1100.degree. C. Temperature and vacuum environment are maintained while controlling indenter motion, sample position, and providing magnified visual inspection during the test.
Type:
Grant
Filed:
December 21, 1992
Date of Patent:
November 8, 1994
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: A cathode in an MPD thruster has an internal heater and utilizes low work function material. The cathode is preheated to operating temperature, and then the thruster is fired by discharging a capacitor bank in a pulse forming network.
Type:
Grant
Filed:
June 25, 1993
Date of Patent:
October 25, 1994
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: The present invention is directed to an augmented thermal bus. In the present design a plurality of thermo-electric heat pumps are used to couple a source plate to a sink plate. Each heat pump is individually controlled by a model based controller. The controller coordinates the heat pumps to maintain isothermality in the source.
Type:
Grant
Filed:
June 25, 1993
Date of Patent:
September 27, 1994
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: Synthetic procedures to tetraalkyls, tetraacids and dianhydrides substituted 1,1,1-triaryl-2,2,2-trifluoroethanes which comprises: (1) 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethane, (2) 1,1-bis(dicarboxyaryl)-1-aryl-2,2,2-trifluoroethane or (3) cyclic dianhydride or diamine of 1,1-bis(dialkylaryl)-1-aryl-2,2,2-trifluoroethanes. The synthesis of (1) is accomplished by the condensation reaction of an aryltrifluoromethyl ketone with a dialkylaryl compound. The synthesis of (2) is accomplished by oxidation of (1). The synthesis dianhydride of (3) is accomplished by the conversion of (2) to its corresponding cyclic dianhydride. The synthesis of the diamine is accomplished by the similar reaction of an aryltrifluoromethyl ketone with aniline or alkyl substituted or disubstituted anilines. Also, other derivatives of the above are formed by nucleophilic displacement reactions.
Type:
Grant
Filed:
January 17, 1992
Date of Patent:
August 2, 1994
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: A high-temperature hybrid seal is constructed of multiple elements to meet the many demands placed on the seal. The primary elements are: a central high-temperature bellows, a braided ceramic sheath covering the bellows, an outer abrasion resistant sheath covering the ceramic sheath, and a structurally-sound seal-end termination.
Type:
Grant
Filed:
January 22, 1993
Date of Patent:
July 26, 1994
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Abstract: Cr.sub.3 Si is alloyed with molybdenum which produces a two-phase microstructure of (Cr,Mo).sub.3 Si and (Cr,Mo).sub.5 Si.sub.3. About 50 weight percent of molybdenum is present in the alloy. The alloy forms two protective oxides over a wide range of temperatures. Chromium and molybdenum oxide volatize under flowing air at high temperatures above 1200.degree. C. which facilitates the formation of SiO.sub.2 on the surface. Below 1200.degree. C. Cr.sub.2 O.sub.3 is formed. The new alloy has excellent high temperature strength and creep properties.
Type:
Grant
Filed:
May 26, 1993
Date of Patent:
July 19, 1994
Assignee:
The United States of America, as represented by the Administrator of the National Aeronautics & Space Administration