Paul R. Coronado and John F. Poco
Flexible Aerogel Composite for Mechanical Stability and Process of Fabrication
U.S. Patent 5,973,015
October 26, 1999
A flexible aerogel and process of fabrication. An aerogel solution is mixed with fibers in a mold and allowed to gel. The gel is then processed by supercritical extraction or air drying to produce a flexible aerogel formed to the shape of the mold. The flexible aerogel has excellent thermal and acoustic properties and can be used in numerous applications, such as for energy absorption and for temperature and acoustic insulation, especially in the contours of aircraft and where space is limited. The flexible aerogel may be of an inorganic (silica) or organic (carbon) type, containing fibers of same.
Jordin T. Kare
Method and Apparatus for Reducing Range Ambiguity in Synthetic Aperture Radar
U.S. Patent 5,973,634
October 26, 1999
A modified synthetic aperture radar system with reduced sensitivity to range ambiguities. It uses secondary receiver channels to detect the range-ambiguous signals and subtract them from the signal received by the main channel. Both desired and range-ambiguous signals are detected by a main receiver and by one or more identical secondary receivers. All receivers are connected to a common antenna with two or more feed systems offset in elevation. The output of the secondary receiver(s) is then subtracted from the main receiver output in such a way as to cancel the ambiguous signals while only slightly attenuating the desired signal and slightly increasing the noise in the main channel. Thus, output of secondary receiver(s) does not significantly affect the desired signal. The subtraction may be done in real time, or outputs of the receivers may be recorded separately and combined during signal processing.
Charles R. Carrigan and John J. Nitao
Electro-Osmotic Infusion for Joule Heating Soil Remediation Techniques
U.S. Patent 5,975,799
November 2, 1999
A method of using electro-osmotic infusion of groundwater or chemically tailored electrolyte to enhance, maintain, or recondition electrical conductivity during joule-heating remediation. Induced flows can be used to infuse electrolyte with enhanced ionic conductivity into the vicinity of the electrodes, maintain the local saturation of near-electrode regions, and resaturate a partially dried-out zone with groundwater. Electro-osmotic infusion can also tailor the conductivity throughout the target layer by infusing chemically modified or heated electrolyte to improve conductivity contrast of the interior. Periodic polarity reversals will prevent large pH changes at the electrodes. This infusion method can be used to condition the electrical conductivity of the soil, particularly low-permeability soil, before and during the heating operation. Electro-osmotic infusion is carried out by locating one or more electrodes adjacent to the heating electrodes and applying a dc potential between two or more electrodes. Depending on the polarities of the electrodes, the induced flow will be toward the heating electrodes or away from them. In addition, electrodes carrying a dc potential may be located throughout the target area to tailor its conductivity.
James C. Davidson and Joseph W. Balch
Microinjector Sample Delivery System for Charged Molecules
U.S. Patent 5,980,713
November 9, 1999
A microinjector sample delivery system for charged molecules. The injector is used for collecting and delivering controlled amounts of charged molecule samples for subsequent analysis. The injector delivery system can be scaled to large numbers (greater than 96) for sample delivery to massively parallel high-throughput analysis systems. The essence of the injector system is an electric-field-controllable loading tip that includes a section of porous material. By applying the appropriate polarity bias potential to the injector tip, charged molecules will migrate into porous material, and by reversing the polarity bias potential, the molecules are ejected or forced away from the tip. The invention has application for uptake of charged biological molecules (for example, proteins, nucleic acids, polymers, for delivery to analytical systems and for use in automated sample delivery systems.
Richard A. Van Konynenburg and Joseph C. Farmer
Means for Limiting and Ameliorating Electrode Shorting
U.S. Patent 5,980,718
November 9, 1999
A fuse and filter arrangement for limiting and ameliorating electrode shorting in capacitive deionization water purification systems that use, for example, carbon aerogel. This arrangement limits and ameliorates the effects of conducting particles or debonded carbon aerogel in shorting the electrodes of a system such as a capacitive deionization water purification system. This limiting and amelioration are important because of the small interelectrode spacing and the finite possibility of debonding or fragmentation of carbon aerogel in a large system. The fuse and filter arrangement electrically protects the entire system from shutting down if a single pair of electrodes is shorted and mechanically prevents a conduction particle from migrating through the electrode stack and shorting the series of electrode pairs in sequence. It also limits the amount of energy released in a shorting event. The arrangement consists of a set of circuit breakers or fuses with one fuse or breaker in the power line connected to one electrode of each electrode pair as well as a set of screens or filters in the water flow channels between each set of electrode pairs.
Brian D. Andresen and Fred S. Miller
Ultratrace Detector for Hand-Held Gas Chromatography
U.S. Patent 5,980,832
November 9, 1999
An ultratrace detector system for handheld chromatography. The system has high sensitivity to emissions generated during production of weapons, biological compounds, and drugs. The system is insensitive to water, air, helium, argon, oxygen, and carbon dioxide. It is composed of a handheld capillary gas chromatograph (GC), an insulated heated redox chamber, a detection chamber, and a vapor trap. The system may, for example, use gas-phase redox reactions and spectral absorption of mercury vapor. The GC initially separates compounds that percolate through a bed of heated mercuric oxide (HgO) in a silica (or other metal) aerogel, which acts as an insulator. Compounds easily oxidized by HgO liberate atomic mercury, which subsequently passes through a detection chamber. This chamber includes a detector cell (such as quartz) illuminated with a 254-nanometer ultraviolet mercury discharge lamp that generates the exact mercury absorption bands used to detect the liberated mercury atoms. Atomic mercury, which strongly absorbs 254-nanometer energy, is therefore a specific signal for reducing compounds eluting from the capillary GC, whereafter it is trapped in, for example, a silicon-aerogel trap.