Patents Represented by Attorney Arthur A. Smith, Jr.
  • Patent number: 4526789
    Abstract: Cataract formation in mammalian lenses can be prevented or reversed by applying a solution of an aldehyde, an acrylamide or a glycol to the lens under conditions that permit the solution to interact with the lens constituents.
    Type: Grant
    Filed: September 19, 1983
    Date of Patent: July 2, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: John I. Clark, Loretta S. Mengel, George B. Benedek
  • Patent number: 4525871
    Abstract: An electronic mixer is decribed which utilizes an optoelectronic switch formed from a semi-insulating substrate of indium phosphide doped with a deep level impurity and disposed intermediate a microstrip transmission line. One conductor of the transmission line has a small gap in its metallization. Upon illumination of the gap by laser pulses from a laser source which are absorbed near the semiconductor surface, a photo-generated electron-hole plasma forms thereby providing a conducting path across the gap. An RF signal to be mixed with a LO signal is coupled to one side of the switch. The LO signal controls the Laser source. The output of the switch is therefore the product of the RF and LO signal.
    Type: Grant
    Filed: February 3, 1982
    Date of Patent: June 25, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: Arthur G. Foyt, Frederick J. Leonberger, Richard C. Williamson
  • Patent number: 4522753
    Abstract: A method for preserving the porosity of porous materials is disclosed. In this method, the porous material is subjected to elevated temperature and vacuum conditions to thereby produce a dimensionally-stable, non-collapsible porous material.
    Type: Grant
    Filed: July 29, 1981
    Date of Patent: June 11, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: Ioannis V. Yannas, John F. Burke, Peter J. Stasikelis
  • Patent number: 4518219
    Abstract: A three-dimensional optical waveguide is disclosed. This waveguide comprises a single crystal semiconductor layer grown upon an insulator which has an index of refraction lower than the semiconductor. The semiconductor layer has a thickness which provides confinement of light propagating in the semiconductor layer in the vertical direction. An effective larger index of refraction over a cross-sectional region of the semiconductor layer provides confinement of light in the lateral direction. This lateral confinement is achieved by side walls in the semiconductor layer which extend toward, but fall short of, the insulator layer.
    Type: Grant
    Filed: February 3, 1983
    Date of Patent: May 21, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: Frederick J. Leonberger, Ivars Melngailis, Carl O. Bozler, Robert W. McClelland
  • Patent number: 4515430
    Abstract: An integrated optical transducer includes a single mode input optical waveguide, two single mode optical waveguide branches having different physical lengths, and a single mode output optical waveguide. When used as a transducer, the optical path lengths of the waveguide branches are dependent on the physical quantity measured. A plurality of such transducer elements may be used jointly to provide a binary output of high sensitivity and wide range of measurement. The waveguide element may also be used as an optical pulse source.
    Type: Grant
    Filed: June 10, 1983
    Date of Patent: May 7, 1985
    Assignee: Massachusetts Institute of Technology
    Inventor: Leonard M. Johnson
  • Patent number: 4514581
    Abstract: Improvements in solar cells based upon low cost semiconductors, such as amorphous silicon, are disclosed. The improved solar cells of this invention have ultrathin active semiconductor layers having a thickness between 0.1 t.sub..alpha. and L.sub.m wherein t.sub..alpha. is the solar spectrum absorption length and L.sub.m is the diffusion length for photogenerated minority charge carriers in the active layer. The back surface reflector has a solar spectrum reflectivity of 70% or greater, so that incident energy not absorbed in a direct pass through the active layer is reflected for another pass. The most preferred embodiment of the cells described herein are shaped to have a light-trapping structure so that light makes mulitple passes through the thin semiconductor layers.
    Type: Grant
    Filed: November 8, 1982
    Date of Patent: April 30, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: John C. C. Fan, Carl O. Bozler
  • Patent number: 4512822
    Abstract: A welding flux binder is provided which comprises an alkali-alkaline earth silicate hydrolyzed and polymerized from tetraalkylorthosilicate, Si(OR).sub.4, wherein R is --CH.sub.3, --C.sub.2 H.sub.5, or --C.sub.3 H.sub.7, and alkali and alkaline earth salts. The reaction product of the tetraalkylorthosilicate and metal salts, M.sub.2 O.M'O.SiO.sub.2, where M is potassium, sodium or lithium, and M' is magnesium, calcium or barium, has several advantages as a welding flux binder. For example, it is not hygroscopic and can be prepared at low temperatures since the alkali ions lower the melting point for viscous sintering of the gel phase. Because of the low temperature processing, a wide variety of solid additives with low thermal stability, such as some metals, carbonates, and fluorides, can be incorporated into the flux. Other dopants may also be readily incorporated into the binder during the gel phase.
    Type: Grant
    Filed: June 29, 1984
    Date of Patent: April 23, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: Eric A. Barringer, Thomas W. Eagar
  • Patent number: 4512964
    Abstract: Nitric oxide is formed by the oxidation of ammonia. An ammonia containing gas is contacted with an oxidation catalyst comprising stainless steel in the presence of oxygen at a temperature between about 500.degree. C. and 1100.degree. C. in order to effect a reaction selectivity of at least 50%.
    Type: Grant
    Filed: March 21, 1984
    Date of Patent: April 23, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: Costas G. Vayenas, Catherine E. Teague
  • Patent number: 4509360
    Abstract: An apparatus and method for measuring particle agglomeration or dispersion in fluid mixtures, such as polymer melts, resides in a piezoelectric transducer, a spherical fused quartz lens, and a fluid housing. A repetitive, broadband, ultrasonic wave is produced by the transducer and is sent into the lens, which also serves to isolate the transducer from the mixture. The ultrasonic wave meets a spherical dimple at the end of the lens which focuses a portion of it into a diffraction limited spot or "interrogation zone". Since the intensity of the wave is large in the interrogation zone, small changes in the impedance of the fluid in this zone, caused by passing agglomerates, will cause large fluctuations in the intensity of the back scattered wave, which is monitored by the transducer between pulses and displayed by associated electronic elements.
    Type: Grant
    Filed: June 24, 1983
    Date of Patent: April 9, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: Lewis Erwin, Jeffrey L. Dohner
  • Patent number: 4508431
    Abstract: Apparatus for steering a principal beam of electromagnetic radiation consisting of a photorefractive material situated such that the principal beam of radiation passes therethrough, the material being photoconductive and having an index of refraction that is variable in response to transverse electro-optical effects; and variable writing means for irradiating the material in a direction orthogonal to the principal beam with two beams which intersect at a variable angle so as to write a diffraction grating in the material and thereby vary the index of refraction of the material, thus steering the principal beam.
    Type: Grant
    Filed: January 11, 1982
    Date of Patent: April 2, 1985
    Assignee: Massachusetts Institute of Technology
    Inventor: Philip D. Henshaw
  • Patent number: 4505266
    Abstract: This invention relates to the introduction of viable cells into a fibrous lattice by surgical, force-utilizing, or other manipulative techniques, all of which are referred to herein as "seeding." One embodiment comprises an autografting technique which involves intact tissue. Other embodiments which involve the distribution of an aqueous suspension of cells comprise centrifugal, spraying, pipetting and syringe emplacement. Each cell that survives the seeding process may reproduce into a colony of cells which grow until they reach confluence, thereby creating a uniform layer or volume of tissue. By proper placement of cells capable of generating such colonies, the period of recovery of a wound may be drastically reduced.
    Type: Grant
    Filed: April 17, 1984
    Date of Patent: March 19, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: Ioannis V. Yannas, John F. Burke
  • Patent number: 4505587
    Abstract: A high speed sampling technique is proposed using a cascade of optical waveguide interferometers driven by CW sinusoidal traveling or standing microwaves. Each interferometer multiplies the optical signal by a function closely approximated by cos.sup.4 .omega.t, where .omega. is the frequency of its microwave drive. A cascade of four interferometers with 2.6 V microwave drives at 10, 20, 40, and 80 GHz and a total length of 2 cm can sample an optical signal with 2 ps resolution and 50 ps between samples.
    Type: Grant
    Filed: August 14, 1981
    Date of Patent: March 19, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: Hermann A. Haus, Steven T. Kirsch, Frederick J. Leonberger
  • Patent number: 4501966
    Abstract: Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface.
    Type: Grant
    Filed: March 13, 1981
    Date of Patent: February 26, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: Steven E. Forman, James W. Caunt
  • Patent number: 4500919
    Abstract: A system for reproducing a color original in a medium using a selected multiplicity of reproduction colorants, comprising: a scanner for producing from said color original a train of appearance signals dependent on at least three color values of said original; aesthetic correction circuitry for introducing aesthetically desired alteration into said appearance signals to produce modified appearance signals; and colorant selection mechanism for receiving said modified appearance signals and for selecting corresponding reproduction signals representing values of said reproduction colorants to produce in said medium a color match of said modified appearance signals.
    Type: Grant
    Filed: May 4, 1982
    Date of Patent: February 19, 1985
    Assignee: Massachusetts Institute of Technology
    Inventor: William F. Schreiber
  • Patent number: 4499441
    Abstract: A superconducting transversal filter circuit for processing signals in the 2-20 GHz range consisting of a miniature transmission line of niobium or similar material, a series of taps for coupling the input and output, and cryogenic refrigerator.
    Type: Grant
    Filed: October 14, 1982
    Date of Patent: February 12, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: John T. Lynch, Alfredo C. Anderson, Richard S. Withers, Peter V. Wright
  • Patent number: 4499007
    Abstract: Polyacetylene, doped with iodine, can be stabilized against aqueous deterioration by immersion in moderately concentrated chloride solutions.
    Type: Grant
    Filed: December 13, 1982
    Date of Patent: February 12, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: Anthony Guiseppi-Elie, Gary E. Wnek
  • Patent number: 4496539
    Abstract: This invention discloses a method of using galactose-binding lectins, such as Ricinus communis agglutinin I (RCA.sub.I), to kill cancer cells. RCA.sub.I has been found to severely weaken certain types of cancer cells, such as bladder carcinoma. This weakening can kill substantial numbers of cancer cells. In addition, it is possible to attach RCA.sub.I to other substances which impose stress on cells, such as cytotoxic drugs or enzymes that catalyze exothermic reactions, which can kill weakened cancer cells.
    Type: Grant
    Filed: February 1, 1982
    Date of Patent: January 29, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: George M. Plotkin, Charles J. Bendrick, George Wolf
  • Patent number: 4495090
    Abstract: A process for selectively etching an aluminum-containing coating in preference to a masking material on a surface of the aluminum-containing coating by positioning a patterned masking material on the aluminum-containing coating in a radio frequency plasma etching chamber and introducing an etchant gas and a source of oxygen and silicon to the interior of the chamber under conditions where silicon dioxide is deposited selectively on masking material layer while the unmasked aluminum-containing coating is etched.
    Type: Grant
    Filed: September 12, 1983
    Date of Patent: January 22, 1985
    Assignee: Massachusetts Institute of Technology
    Inventor: Christopher M. Horwitz
  • Patent number: 4491605
    Abstract: Conductive materials are formed by implanting high energy ions (30 keV to 300 keV) into rigid backboned polymers, such as poly (p-phenylene sulfide); conductivities on the order of 10.sup.-3 (ohm-cm).sup.-1 are demonstrated and the materials remain stable over periods as long as a year.
    Type: Grant
    Filed: June 23, 1982
    Date of Patent: January 1, 1985
    Assignee: Massachusetts Institute of Technology
    Inventors: Harry Mazurek, David R. Day, Edward W. Maby, Jonathan S. Abel
  • Patent number: 4490445
    Abstract: Solid oxide electrochemical energy converters are capable of generating electricity from gaseous chemical fuels as well as producing fuels while consuming electricity. The converters consist of electrochemical cell stacks and heat exchanger stacks. An electrochemical cell stack comprises alternating solid oxide electrolyte plates and electrical conductor plates to form a electrically connected package. Means are provided to direct gases to the surfaces of the electrolyte plates where the electrodes perform the energy conversion. The heat exchanger stack consisting of multiple layers of ceramic or metal plates provides temperature conditioning on incoming reacting gases.
    Type: Grant
    Filed: May 24, 1982
    Date of Patent: December 25, 1984
    Assignee: Massachusetts Institute of Technology
    Inventor: Michael S. Hsu