Patents Assigned to Midwest Research Institute
-
Patent number: 5316593Abstract: A high-efficiency 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. A passivating window layer of defined composition is disposed over the emitter layer. The conversion efficiency 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 window layer.Type: GrantFiled: November 16, 1992Date of Patent: May 31, 1994Assignee: Midwest Research InstituteInventors: Jerry M. Olson, Sarah R. Kurtz
-
Patent number: 5313858Abstract: A device for removing a rubber stopper from a test tube is mountable to an upright wall, has a generally horizontal splash guard, and a lower plate spaced parallel to and below the splash guard. A slot in the lower plate has spaced-apart opposing edges that converge towards each other from the plate outer edge to a narrowed portion, the opposing edges shaped to make engagement between the bottom of the stopper flange and the top edge of the test tube to wedge therebetween and to grasp the stopper in the slot narrowed portion to hold the stopper as the test tube is manipulated downwardly and pulled from the stopper. The opposing edges extend inwardly to adjoin an opening having a diameter significantly larger than that of the stopper flange.Type: GrantFiled: March 8, 1993Date of Patent: May 24, 1994Assignee: Midwest Research InstituteInventor: Robert R. Stitt
-
Patent number: 5314571Abstract: A liquid phase epitaxy method for forming thin crystalline layers of device quality silicon having less than 5X10.sup.16 Cu atoms/cc impurity, comprising: preparing a saturated liquid solution melt of Si in Cu at about 16% to about 90% wt. Si at a temperature range of about 800.degree. C. to about 1400.degree. C. in an inert gas; immersing a substrate in the saturated solution melt; supersaturating the solution by lowering the temperature of the saturated solution melt and holding the substrate immersed in the solution melt for a period of time sufficient to cause growing Si to precipitate out of the solution to form a crystalline layer of Si on the substrate; and withdrawing the substrate from the solution.Type: GrantFiled: May 13, 1992Date of Patent: May 24, 1994Assignee: Midwest Research InstituteInventor: Theodore F. Ciszek
-
Patent number: 5304509Abstract: A two-step back-side hydrogenation process includes the steps of first bombarding the back side of the silicon substrate with hydrogen ions with intensities and for a time sufficient to implant enough hydrogen atoms into the silicon substrate to potentially passivate substantially all of the defects and impurities in the silicon substrate, and then illuminating the silicon substrate with electromagnetic radiation to activate the implanted hydrogen, so that it can passivate the defects and impurities in the substrate. The illumination step also annihilates the hydrogen-induced defects. The illumination step is carried out according to a two-stage illumination schedule, the first or low-power stage of which subjects the substrate to electromagnetic radiation that has sufficient intensity to activate the implanted hydrogen, yet not drive the hydrogen from the substrate.Type: GrantFiled: August 24, 1992Date of Patent: April 19, 1994Assignee: Midwest Research InstituteInventor: Bhushan L. Sopori
-
Patent number: 5300704Abstract: 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 thType: GrantFiled: December 4, 1992Date of Patent: April 5, 1994Assignee: Midwest Research InstituteInventors: Robert J. Evans, Helena L. Chum
-
Patent number: 5275944Abstract: A purified low molecular weight cellulase endoglucanase I having a molecular weight of between about 57,420 to about 74,580 daltons from Acidothermus cellulolyticus (ATCC 43068). The cellulase 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 83.degree. C. at pH's from about 2 to about 9, and in inactivation temperature of about 110.degree. C. at pH's from about 2 to about 9.Type: GrantFiled: January 27, 1992Date of Patent: January 4, 1994Assignee: Midwest Research InstituteInventors: Michael E. Himmel, William S. Adney, Melvin P. Tucker, Karel Grohmann
-
Patent number: 5250427Abstract: A process is described for converting organic materials (such as biomass wastes) into a bioplastic suitable for use as a biodegradable plastic. In a preferred embodiment the process involves thermally gasifying the organic material into primarily carbon monoxide and hydrogen, followed by photosynthetic bacterial assimilation of the gases into cell material. The process is ideally suited for waste recycling and for production of useful biodegradable plastic polymer.Type: GrantFiled: June 25, 1992Date of Patent: October 5, 1993Assignee: Midwest Research InstituteInventors: Paul F. Weaver, Pin-Ching Maness
-
Patent number: 5223601Abstract: A process for preparing phenol-formaldehyde novolak resins and molding compositions in which portions of the phenol normally contained in said resins are replaced by a phenol/neutral fractions extract obtained from fractionating fast-pyrolysis oils. The fractionation consists of a neutralization stage which can be carried out with aqueous solutions of bases or appropriate bases in the dry state, followed by solvent extraction with an organic solvent having at least a moderate solubility parameter and good hydrogen bonding capacity.Phenolic compounds-containing/neutral fractions extracts obtained by fractionating fast-pyrolysis oils from a lignocellulosic material, is such that the oil is initially in the pH range of 2-4, being neutralized with an aqueous bicarbonate base, and extracted into a solvent having a solubility parameter of approximately 8.4-9.11 [cal/cm.sup.3 ].sup.1/2 with polar components in the 1.8-3.0 range and hydrogen bonding components in the 2-4.Type: GrantFiled: January 29, 1991Date of Patent: June 29, 1993Assignee: Midwest Research Institute Ventures, Inc.Inventors: Helena L. Chum, Stuart K. Black, James P. Diebold, Roland E. Kreibich
-
Patent number: 5216149Abstract: 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 thType: GrantFiled: June 7, 1991Date of Patent: June 1, 1993Assignee: Midwest Research InstituteInventors: Robert J. Evans, Helena L. Chum
-
Patent number: 5194349Abstract: A process for preparing a multiple level logic optical memory disks which are erasable upon heating when ion-beam hydrogenation is used for writing informatin on the disk.The process comprises depositing an amorphous film selected from the group consisting of silicon hydride, silicon carbon hydride and silicon nitrogen hydride on a glass substrate using plasma enhanced chemical vapor deposition at temperatures sufficient to ensure good adhesion and high film quality and an optical bandgap of between aboout 1.55 and about 2.0 eV; writing information on these disks by using a laser beam to selectively heat spots of the film to expel hydrogen and change the bandgap and optical absorption of the film; and using a laser beam at a sufficient nm wavelength in order to detect information stored on these disks.Type: GrantFiled: February 7, 1992Date of Patent: March 16, 1993Assignee: Midwest Research InstituteInventors: Y. Simon Tsuo, Jack L. Stone
-
Patent number: 5175975Abstract: An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.Type: GrantFiled: March 23, 1992Date of Patent: January 5, 1993Assignee: Midwest Research InstituteInventors: David K. Benson, Thomas F. Potter
-
Patent number: 5168748Abstract: A method and apparatus for simulating leakage from a liquid storage tank to test the accuracy of leak measurement instruments. An elongated pipe string formed by pipes connected end to end is extended into the tank. An end cap on the bottom of the pipe carries an inner cylinder which is smaller than the pipe and concentric with it. The inner cylinder is open at the top and, if it be an underground tank, may be loaded with fill material of the type that surrounds the tank. An orifice mounted to the end cap simulates a tank leak and allows liquid from the tank to flow through the backfill material into the pipe. A multiple orifice assembly may be remotely operated to change the orifice characteristics. The liquid in the pipe is collected for measurement to determine the leakage quantity.Type: GrantFiled: April 29, 1991Date of Patent: December 8, 1992Assignee: Midwest Research InstituteInventors: Jairus D. Flora, Jr., H. Kendall Wilcox
-
Patent number: 5166761Abstract: A multiple wavelength LED having a monolithic cascade cell structure comprising at least two p-n junctions, wherein each of said at least two p-n junctions have substantially different band gaps, and electrical connector means by which said at least two p-n junctions may be collectively energized; and wherein said diode comprises a tunnel junction or interconnect.Type: GrantFiled: April 1, 1991Date of Patent: November 24, 1992Assignee: Midwest Research InstituteInventors: Jerry M. Olson, Sarah R. Kurtz
-
Patent number: 5157893Abstract: Improved compact insulation panel is provided which is comprised of two adjacent metal sheets spaced close together with a plurality of spherical, or other discretely shaped, glass or ceramic beads optimally positioned between the sheets to provide support and maintain the spacing between the metal sheets when the gases therebetween are evacuated to form a vacuum. These spherical glass beads provide the maximum support while minimizing thermal conductance. In its preferred embodiment; these two metal sheets are textured with ribs or concave protrusions in conjunction with the glass beads to maximize the structural integrity of the panels while increasing the spacing between beads, thereby reducing the number of beads and the number of thermal conduction paths.Type: GrantFiled: June 12, 1990Date of Patent: October 27, 1992Assignee: Midwest Research InstituteInventors: David K. Benson, Thomas F. Potter
-
Patent number: 5110735Abstract: A substantially purified high molecular weight cellulase enzyme having a molecular weight of between about 156,000 to about 203,400 daltons isolated from the bacterium Acidothermus cellulolyticus (ATCC 43068) and a method of producing it are disclosed. The enzyme is water soluble, possesses both C.sub.1 and C.sub.x types of enzymatic activity, has a high degree of stability toward heat and exhibits both a high optimum temperature activity and high inactivation characteristics.Type: GrantFiled: September 26, 1989Date of Patent: May 5, 1992Assignee: Midwest Research InstituteInventors: Melvin P. Tucker, Karel Grohmann, Michael E. Himmel, Ali Mohagheghi
-
Patent number: 5107649Abstract: An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.Type: GrantFiled: February 1, 1990Date of Patent: April 28, 1992Assignee: Midwest Research InstituteInventors: David K. Benson, Thomas F. Potter
-
Patent number: 5091499Abstract: A process for preparing phenol-formaldehyde resole resins and adhesive compositions in which portions of the phenol normally contained in said resins are replaced by a phenol/neutral fractions extract obtained from fractionating fast-pyrolysis oils.Type: GrantFiled: December 29, 1989Date of Patent: February 25, 1992Assignee: Midwest Research InstituteInventors: Helena L. Chum, Roland E. Kreibich
-
Patent number: 5041361Abstract: A method of providing and developing a resist on a substrate for constructing integrated circuit (IC) chips includes the following steps: of depositing a thin film of amorphous silicon or hydrogenated amorphous silicon on the substrate and exposing portions of the amorphous silicon to low-energy oxygen ion beams to oxidize the amorphous silicon at those selected portions. The nonoxidized portions are then removed by etching with RF-excited hydrogen plasma. Components of the IC chip can then be constructed through the removed portions of the resist. The entire process can be performed in an in-line vacuum production system having several vacuum chambers. Nitrogen or carbon ion beams can also be used.Type: GrantFiled: December 27, 1989Date of Patent: August 20, 1991Assignee: Midwest Research InstituteInventor: Y. Simon Tsuo
-
Patent number: 5011517Abstract: An instrument for removing chemical vapors from air and concentrating the chemical vapors in a liquid scrubbing medium has been invented. A cylindrical receptacle receives a preselected amount of scrubbing liquid. Air is pulled tangentially into the cylinder through an inlet slit and swirls toward the cylinder top, carrying the liquid with it so that the cylinder wall is coated with the liquid. At the end of a sampling cycle, the air flow is shut off and the liquid is allowed to settle before being drained off for analysis. A cleaning cycle between sampling cycles is possible, during which the cylinder can be heated by an electrical heater cable.Type: GrantFiled: February 12, 1990Date of Patent: April 30, 1991Assignee: Midwest Research InstituteInventors: Brian R. Cage, Arbor D. Drinkwine
-
Patent number: 4964995Abstract: A process is disclosed for separating low molecular weight components from complex aqueous organic mixtures. The process includes preparing a separation solution of supercritical carbon dioxide with an effective amount of an entrainer to modify the solvation power of the supercritical carbon dioxide and extract preselected low molecular weight components. The separation solution is maintained at a temperature of at least about 70.degree. C. and a pressure of at least about 1,500 psi. The separation solution is then contacted with the organic mixtures while maintaining the temperature and pressure as above until the mixtures and solution reach equilibrium to extract the preselected low molecular weight components from the organic mixtures. Finally, the entrainer/extracted components portion of the equilibrium mixture is isolated from the separation solution.Type: GrantFiled: June 16, 1989Date of Patent: October 23, 1990Assignee: Midwest Research InstituteInventors: Helena L. Chum, Giuseppe Filardo