Patents Assigned to Midwest Research Institute
  • Patent number: 5391896
    Abstract: A single-crystal, monolithic, tandem, multi-color optical transceiver device is described, including (a) an InP substrate having upper and lower surfaces, (b) a first junction on the upper surface of the InP substrate, (c) a second junction on the first junction. The first junction is preferably GaInAsP of defined composition, and the second junction is preferably InP. The two junctions are lattice matched. The second junction has a larger energy band gap than the first junction. Additional junctions having successively larger energy band gaps may be included. The device is capable of simultaneous and distinct multi-color emission and detection over a single optical fiber.
    Type: Grant
    Filed: September 2, 1992
    Date of Patent: February 21, 1995
    Assignee: Midwest Research Institute
    Inventor: Mark W. Wanlass
  • Patent number: 5386070
    Abstract: A process of using fast pyrolysis in a carrier gas to convert a polystyrene and polyphenylene oxide plastic waste to a given polystyrene and polyphenylene oxide prior to pyrolysis of other plastic components therein comprising:selecting a first temperature range to cause pyrolysis of given polystyrene and polyphenylene oxide and its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components;selecting a catalyst and a support and treating the feed stream with the catalyst to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of high value monomeric constituent of styrene from polystyrene and polyphenylene oxide in the first temperature range;differentially heating the feed stream at a heat rate within the first temperature range to provide differential pyrolysis for selective recovery of the high value monomeric constituent of styrene from polystyrene and polyphenylene oxide prior to pyrolysis of other plastic components;
    Type: Grant
    Filed: October 27, 1992
    Date of Patent: January 31, 1995
    Assignee: Midwest Research Institute
    Inventors: Robert J. Evans, Helena L. Chum
  • Patent number: 5384653
    Abstract: A variable transmittance double pane window includes an electrochromic material that has been deposited on one pane of the window in conjunction with an array of photovoltaic cells deposited along an edge of the pane to produce the required electric power necessary to vary the effective transmittance of the window. A battery is placed in a parallel fashion to the array of photovoltaic cells to allow the user the ability to manually override the system when a desired transmittance is desired.
    Type: Grant
    Filed: November 6, 1992
    Date of Patent: January 24, 1995
    Assignee: Midwest Research Institute
    Inventors: David K. Benson, Richard S. Crandall, Satyendra K. Deb, Jack L. Stone
  • Patent number: 5383512
    Abstract: Methods for manufacturing a self-supporting substrate having a plurality of spaced-apart needles (spikes or microcapillaries) projecting upwardly from a major surface of the substrate. In a preferred method, metal is deposited onto a porous membrane such that the metal extends into the pores, after which the membrane is dissolved.
    Type: Grant
    Filed: May 24, 1993
    Date of Patent: January 24, 1995
    Assignee: Midwest Research Institute
    Inventor: Eric E. Jarvis
  • Patent number: 5380445
    Abstract: Methods are described for pretreating microbial sludges to break cells and disrupt organic matter. One method involves the use of sonication, and another method involves the use of shear forces. The pretreatment of sludge enhances bioconversion of the organic fraction. This allows for efficient dewatering of the sludge and reduces the cost for final disposal of the waste.
    Type: Grant
    Filed: October 22, 1993
    Date of Patent: January 10, 1995
    Assignee: Midwest Research Institute
    Inventors: Christopher J. Rivard, Nicholas J. Nagle
  • Patent number: 5377037
    Abstract: A variable transmittance optical component includes an electrochromic material and a photovoltaic device-type thin film solar cell deposited in a tandem type, monolithic single coating over the component. A bleed resistor of a predetermined value is connected in series across the electrochromic material and photovoltaic device controlling the activation and deactivation of the electrochromic material. The electrical conductivity between the electrochromic material and the photovoltaic device is enhanced by interposing a transparent electrically conductive layer.
    Type: Grant
    Filed: November 6, 1992
    Date of Patent: December 27, 1994
    Assignee: Midwest Research Institute
    Inventors: Howard M. Branz, Richard S. Crandall, C. Edwin Tracy
  • Patent number: 5376185
    Abstract: A single-junction solar cell having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of "pinning" the optimum band gap for a wide range of operating conditions at a value of 1.14.+-.0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap.
    Type: Grant
    Filed: May 12, 1993
    Date of Patent: December 27, 1994
    Assignee: Midwest Research Institute
    Inventor: Mark W. Wanlass
  • Patent number: 5371212
    Abstract: High purity levoglucosan is obtained from pyrolysis oil derived from cellulose by: mixing pyrolysis oil with water and a basic metal hydroxide, oxide, or salt in amount sufficient to elevate pH values to a range of from about 12 to about 12.5, and adding an amount of the hydroxide, oxide, or salt in excess of the amount needed to obtain the pH range until colored materials of impurities from the oil are removed and a slurry is formed; drying the slurry azeotropically with methyl isobutyl ketone solvent to form a residue, and further drying the residue by evaporation; reducing the residue into a powder; continuously extracting the powder residue with ethyl acetate to provide a levoglucosan-rich extract; and concentrating the extract by removing ethyl acetate to provide crystalline levoglucosan. Preferably, Ca(OH).sub.2 is added to adjust the pH to the elevated values, and then Ca(OH).sub.2 is added in an excess amount needed.
    Type: Grant
    Filed: September 4, 1992
    Date of Patent: December 6, 1994
    Assignee: Midwest Research Institute
    Inventor: Luc Moens
  • Patent number: 5366884
    Abstract: A purified low molecular weight endoglucanase II from Acidothermus cellulolyticus (ATCC 43068) is disclosed. The endoglucanase is water soluble, possesses both C.sub.1, and C.sub.x types of enzyme activity, a high degree of stability toward heat, and exhibits optimum temperature activity at about 81.degree. C. at pH's from about 2 to about 9, and at a inactivation temperature of about 100.degree. C. at pH's from about 2 to about 9.
    Type: Grant
    Filed: September 21, 1993
    Date of Patent: November 22, 1994
    Assignee: Midwest Research Institute
    Inventors: William S. Adney, Steven R. Thomas, Rafael A. Nieves, Michael E. Himmel
  • Patent number: 5361172
    Abstract: A metallized polymer mirror construction having improved durability against delamination and tunneling, comprising: an outer layer of polymeric material; a metal oxide layer underlying the outer layer of polymeric material; a silver reflective layer underneath the metal oxide layer; and a layer of adhesive attaching the silver layer to a substrate.
    Type: Grant
    Filed: January 21, 1993
    Date of Patent: November 1, 1994
    Assignee: Midwest Research Institute
    Inventors: Paul O. Schissel, Cheryl E. Kennedy, Gary J. Jorgensen, Yvonne D. Shinton, Rita M. Goggin
  • Patent number: 5359099
    Abstract: A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating th
    Type: Grant
    Filed: October 27, 1992
    Date of Patent: October 25, 1994
    Assignee: Midwest Research Institute
    Inventors: Robert J. Evans, Helena L. Chum
  • Patent number: 5358574
    Abstract: A textured backside of a semiconductor device for increasing light scattering and absorption in a semiconductor substrate is accomplished by applying infrared radiation to the front side of a semiconductor substrate that has a metal layer deposited on its backside in a time-energy profile that first produces pits in the backside surface and then produces a thin, highly reflective, low resistivity, epitaxial alloy layer over the entire area of the interface between the semiconductor substrate and a metal contact layer. The time-energy profile includes ramping up to a first energy level and holding for a period of time to create the desired pit size and density and then rapidly increasing the energy to a second level in which the entire interface area is melted and alloyed quickly. After holding the second energy level for a sufficient time to develop the thin alloy layer over the entire interface area, the energy is ramped down to allow epitaxial crystal growth in the alloy layer.
    Type: Grant
    Filed: November 22, 1993
    Date of Patent: October 25, 1994
    Assignee: Midwest Research Institute
    Inventor: Bhushan L. Sopori
  • Patent number: 5359061
    Abstract: A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating th
    Type: Grant
    Filed: October 27, 1992
    Date of Patent: October 25, 1994
    Assignee: Midwest Research Institute
    Inventors: Robert J. Evans, Helena L. Chum
  • Patent number: 5356839
    Abstract: Enhanced quality thin films of Cu.sub.w (In,Ga.sub.y)Se.sub.z for semiconductor device applications are fabricated by initially forming a Cu-rich, phase-separated compound mixture comprising Cu(In,Ga):Cu.sub.x Se on a substrate to form a large-grain precursor and then converting the excess Cu.sub.x Se to Cu(In,Ga)Se.sub.2 by exposing it to an activity of In and/or Ga, either in vapor In and/or Ga form or in solid (In,Ga).sub.y Se.sub.z. Alternatively, the conversion can be made by sequential deposition of In and/or Ga and Se onto the phase-separated precursor. The conversion process is preferably performed in the temperature range of about 300.degree.-600.degree. C., where the Cu(In,Ga)Se.sub.2 remains solid, while the excess Cu.sub.x Se is in a liquid flux. The characteristic of the resulting Cu.sub.w (In,Ga).sub.y Se.sub.z can be controlled by the temperature. Higher temperatures, such as 500.degree.-600.degree. C., result in a nearly stoichiometric Cu(In,Ga)Se.sub.
    Type: Grant
    Filed: April 12, 1993
    Date of Patent: October 18, 1994
    Assignee: Midwest Research Institute
    Inventors: John R. Tuttle, Miguel A. Contreras, Rommel Noufi, David S. Albin
  • Patent number: 5346729
    Abstract: An improved chemical vapor deposition method for depositing transparent continuous coatings of sp.sup.3 -bonded diamond-type carbon films, comprising: a) providing a volatile hydrocarbon gas/H.sub.2 reactant mixture in a cold wall vacuum/chemical vapor deposition chamber containing a suitable substrate for said films, at pressure of about 1 to 50 Torr; and b) directing a concentrated solar flux of from about 40 to about 60 watts/cm.sup.2 through said reactant mixture to produce substrate temperatures of about 750.degree. C. to about 950.degree. C. to activate deposition of the film on said substrate.
    Type: Grant
    Filed: May 17, 1993
    Date of Patent: September 13, 1994
    Assignee: Midwest Research Institute
    Inventors: J. Roland Pitts, C. Edwin Tracy, David E. King, James T. Stanley
  • Patent number: 5342453
    Abstract: A high-efficiency single heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. The conversion effiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer.
    Type: Grant
    Filed: November 13, 1992
    Date of Patent: August 30, 1994
    Assignee: Midwest Research Institute
    Inventor: Jerry M. Olson
  • Patent number: 5338254
    Abstract: A free jet of air is disturbed at a frequency that substantially matches natural turbulences in the free jet to increase the entrainment, mixing, and spreading of air by the free jet, for example in a room or other enclosure. The disturbances are created by pulsing the flow of air that creates the free jet at the desired frequency. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct.
    Type: Grant
    Filed: December 22, 1992
    Date of Patent: August 16, 1994
    Assignee: Midwest Research Institute
    Inventor: Robert B. Farrington
  • Patent number: 5324494
    Abstract: A method is described for producing silicon carbide particles using a silicon source material and a hydrocarbon. The method is efficient and is characterized by high yield. Finely divided silicon source material is contacted with hydrocarbon at a temperature of 400.degree. C. to 1000.degree. C. where the hydrocarbon pyrolyzes and coats the particles with carbon. The particles are then heated to 1100.degree. C. to 1600.degree. C. to cause a reaction between the ingredients to form silicon carbide of very small particle size. No grinding of silicon carbide is required to obtain small particles. The method may be carried out as a batch process or as a continuous process.
    Type: Grant
    Filed: January 21, 1993
    Date of Patent: June 28, 1994
    Assignee: Midwest Research Institute
    Inventor: Gregory C. Glatzmaier
  • Patent number: 5321174
    Abstract: A process of using fast pyrolysis to convert a plastic waste feed stream containing polycarbonate and ABS to high value monomeric constituents prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of a given polymer to its high value monomeric constituents prior to a temperature range that causes pyrolysis of other plastic components; selecting an acid or base catalysts and an oxide or carbonate support for treating the feed stream to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of the high value monomeric constituents of polycarbonate and ABS in the first temperature program range; differentially heating the feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituents prior to pyrolysis or other plastic components; separating the high value monomeric constituents f
    Type: Grant
    Filed: October 27, 1992
    Date of Patent: June 14, 1994
    Assignee: Midwest Research Institute
    Inventors: Robert J. Evans, Helena L. Chum
  • Patent number: 5318108
    Abstract: Disclosed is a dynamic vacuum insulation comprising sidewalls enclosing an evacuated chamber and gas control means for releasing hydrogen gas into a chamber to increase gas molecule conduction of heat across the chamber and retrieving hydrogen gas from the chamber. The gas control means includes a metal hydride that absorbs and retains hydrogen gas at cooler temperatures and releases hydrogen gas at hotter temperatures; a hydride heating means for selectively heating the metal hydride to temperatures high enough to release hydrogen gas from the metal hydride; and gate means positioned between the metal hydride and the chamber for selectively allowing hydrogen to flow or not to flow between said metal hydride and said chamber.
    Type: Grant
    Filed: October 14, 1992
    Date of Patent: June 7, 1994
    Assignee: Midwest Research Institute
    Inventors: David K. Benson, Thomas F. Potter