Patents Represented by Attorney Arthur A. Smith, Jr.
  • Patent number: 4291390
    Abstract: A solid state device capable of providing long-term storage of analog signals which in a particular embodiment utilizes a plurality of MNOS storage elements. An input analog signal is applied to a plurality of temporary storage means each associated with an MNOS storage element for temporarily storing a charge proportional to the amplitude of the portion of the input analog signal applied thereto. Storage control means are used to transfer the temporarily stored charges to the long-term MNOS storage elements so that controlled amounts of carrier charges are stored in the nitride layers thereof, such controlled amounts being substantially linearly proportional to the temporarily stored charges associated therewith. In a particular embodiment the input analog signal may be supplied via a surface acoustic wave (SAW) device and coupled to the MNOS device directly or it may be coupled to a charge-coupled device (CCD) and thence coupled to the MNOS device.
    Type: Grant
    Filed: September 28, 1979
    Date of Patent: September 22, 1981
    Assignee: Massachusetts Institute of Technology
    Inventors: Ernest R. Stern, Richard W. Ralston, Daniel L. Smythe, Jr., Barry E. Burke
  • Patent number: 4291249
    Abstract: A rotating electric machine in which the armature winding thereof and other parts are supported by a liquid to withstand the mechanical stresses applied during transient overloads and the like. In particular, a narrow gap is provided between the armature winding and the stator which supports it and this gap is filled with an externally pressurized viscous liquid. The liquid is externally pressurized sufficiently to balance the static loads on the armature winding. Transient mechanical loads which deform the armature winding alter the gap dimensions and thereby additionally pressurize the viscous liquid to oppose the armature winding deformation and more nearly uniformly to distribute the resulting mechanical stresses.
    Type: Grant
    Filed: April 5, 1979
    Date of Patent: September 22, 1981
    Assignee: Massachusetts Institute of Technology
    Inventors: Joseph L. Smith, Jr., James L. Kirtley, Jr.
  • Patent number: 4289952
    Abstract: Metal or ceramic powders having a narrow size distribution are produced by passing a gas entrained powder through an intense light beam which couples preferentially with the larger particles to heat and selectively vaporize a portion of the larger particles until their diameter approximates the desired size.
    Type: Grant
    Filed: December 12, 1979
    Date of Patent: September 15, 1981
    Assignee: Massachusetts Institute of Technology
    Inventor: John S. Haggerty
  • Patent number: 4290118
    Abstract: A solid state device combining the use of a surface-acoustic-wave (SAW) device and a charge-coupled device (CCD) which utilizes an interface means therebetween comprising a plurality of conductive fingers responsive to an acoustic wave on the SAW device. The conductive fingers are electrically connected at at least one end to the CCD substrate and a plurality of temporary storage means are used for temporarily storing a charge proportional to the voltage potential on the associated conductive finger. The temporary stored charges can be transferred to the storage wells of the CCD for storing a replica of the acoustic wave. The SAW-CCD combination is adapted for use as a buffer memory, an accumulating correlator, or as a matched filter device.
    Type: Grant
    Filed: September 28, 1979
    Date of Patent: September 15, 1981
    Assignee: Massachusetts Institute of Technology
    Inventors: Ernest R. Stern, Richard W. Ralston, Daniel L. Smythe, Jr., Barry E. Burke
  • Patent number: 4287769
    Abstract: A way of automatically inspecting a machined part, for example, to a tolerance of 0.001 inches. A minicomputer monitors a change in phase of acoustic wave energy impinging upon a sample part and compares it with a change in phase of such energy for a standard or master part, any difference between the monitored changes being interpreted to determine if the sample is within acceptable tolerance limits. The inspection approach described uses no moving parts and can be used to inspect many dimensions of a part simultaneously in less than a second. Acoustic wave energy can be used to inspect parts of any shape. The inspection system disclosed can be used, as well, to monitor the geometry of an object over time to note any changes in said geometry. And the concepts of the inspection system can be employed in conjunction with robot-controlled devices to provide close-positioning data for such devices.
    Type: Grant
    Filed: July 11, 1979
    Date of Patent: September 8, 1981
    Assignee: Massachusetts Institute of Technology
    Inventor: Bruce S. Buckley
  • Patent number: 4288424
    Abstract: A physiologically acceptable solution of gallium-68 fluorides, having an activity of 0.1 to 50 millicuries per milliliter of solution is provided. The solution is obtained from a generator comprising germanium-68 hexafluoride bound to a column of an anion exchange resin which forms gallium-68 in situ by eluting the column with an acid solution to form a solution containing .sup.68 Ga-fluorides. The solution then is neutralized prior to administration.
    Type: Grant
    Filed: January 15, 1979
    Date of Patent: September 8, 1981
    Assignee: Massachusetts Institute of Technology
    Inventors: Rudi D. Neirinckx, Michael A. Davis
  • Patent number: 4287485
    Abstract: Double-heterostructure (DH) diode lasers based upon very thin epitaxial layers of Ga.sub.x In.sub.1-x As.sub.y P.sub.1-y grown on and lattice-matched to oriented InP substrates are disclosed. A preferred method for fabricating such lasers involves the successive growth, on an InP substrate, of an InP buffer layer, the GaInAsP active layer and an InP top barrier layer using liquid phase epitaxy techniques to grow these layers from supercooled solutions. Stripe geometry lasers can be fabricated from these materials which emit in the 1.1-1.3 .mu.m range and are capable of cw operation for extended periods at room temperature.
    Type: Grant
    Filed: April 30, 1979
    Date of Patent: September 1, 1981
    Assignee: Massachusetts Institute of Technology
    Inventor: Jaw J. Hsieh
  • Patent number: 4287486
    Abstract: Novel laser resonator cavities and laser wavelength tuning arrangements are disclosed. A pair of similar spectral dispersion means achieve in the resonator both a colinear region for rays of different wavelengths and a region in which rays of different wavelengths coextend separated and substantially parallel. Amplifying medium in an optical cavity following at least a first dispersion means, preferably in the parallel region of a laser having paired dispersion means, enable amplification at the different wavelengths while limiting their coupling via the amplifying medium. One or a number of apertures disposed in a dispersed path within a laser cavity are positioned to transmit a selected ray or rays and to block rays of unwanted wavelength whereby laser oscillation wavelength is determined. The above features are variously combined to achieve colinear output beams of various wavelengths and injection-type control of laser oscillation. Variable reflecting optics, e.g.
    Type: Grant
    Filed: May 14, 1979
    Date of Patent: September 1, 1981
    Assignee: Massachusetts Institute of Technology
    Inventor: Ali Javan
  • Patent number: 4287235
    Abstract: A new technique for fabricating high contrast X-ray masks with precisely controlled linewidths of less than 100 A is described. The technique is based on the deposition at an oblique angle ("shadowing") of X-ray absorber material onto relief structures of triangular or square cross-section in a polyimide plastic membrane. Precise linewidth control is possible because shadowing angle, absorber thickness and relief structure can be precisely determined. The smooth and well-controlled triangular cross-section structures required are produced in silicon by anisotropic chemical etching and then transferred to polyimide by molding. The square structures are made by reactive-ion-etching SiO.sub.2 with CHF.sub.3 and are transferred to polyimide by molding. Results of a numerical model of carbon K (45 A) X-ray exposures in PMMA of shadowed triangular profile masks are presented which indicate that linewidth control of .+-.50 A should be possible for submicrometer period gratings.
    Type: Grant
    Filed: May 29, 1979
    Date of Patent: September 1, 1981
    Assignee: Massachusetts Institute of Technology
    Inventor: Dale C. Flanders
  • Patent number: 4286026
    Abstract: A process for implanting a precise quantity of radioactive metal on a metal substrate such as a cutting tool or other metal part subject to wear at the area or areas where the part is expected to wear during its operation. The presence of the radioactive spot can be sensed to determine the extent of wear during use. The radioactive metal is deposited from a wire formed of a core of the radioactive metal surrounded by a sheath of metal having a high thermal and electrical conductivity relative to the core. In operation, the wire contacts the metal surface under pressure and electric current is passed through the wire in order to (1) form a pit on the tool surface, (2) weld the radioactive metal in the pit and (3) evaporate a small portion of the conductive sheath adjacent the pit. A second current then is passed through the wire to break it near the bottom of the pit, leaving a small quantity of radioactive material welded to the bottom of the pit.
    Type: Grant
    Filed: August 14, 1979
    Date of Patent: August 25, 1981
    Assignee: Massachusetts Institute of Technology
    Inventors: Nathan H. Cook, Krishnamoorthy Subramanian
  • Patent number: 4283799
    Abstract: A pre-coated body implant, such as, for example, a hip prosthesis, in which that portion of the implant that attaches to or is inserted into a skeletal member of the body has a pre-coating of a material (e.g., an acrylic material) covering all or most of said portion and bonded thereto.
    Type: Grant
    Filed: September 10, 1979
    Date of Patent: August 18, 1981
    Assignee: Massachusetts Institute of Technology
    Inventors: George W. Pratt, Jr., Robert Poss, Jeremy K. Chung
  • Patent number: 4283235
    Abstract: A process is described which combine polycrystalline isolation of collectors and shallow oxide isolation of bases. This approach is capable of providing deep dielectric isolation, surface planarity and the high density of walled emitter geometries, a combination heretofore unobtainable by any other means.This isolation scheme has been used to fabricate ECL gate chains. The transistors were located in 2.5 micron thick n epi islands surrounded by 5.times.10.sup.5 ohm-cm polysilicon selectively oxidized with silicon nitride masking to a thickness of one micron. The oxide "bump" at the nitride mask was typically 3000 A and the epi-poly step height was as small as 2600 A. The circuits have polysilicon resistors and were fabricated using both thermal diffusion and ion implantation. The power-delay product of these circuits was approximately one-half that of junction isolated circuits.
    Type: Grant
    Filed: May 15, 1980
    Date of Patent: August 11, 1981
    Assignee: Massachusetts Institute of Technology
    Inventors: Jack I. Raffai, Stephen E. Bernacki
  • Patent number: 4282149
    Abstract: In accordance with this invention, it has been found that carbon and oxygen analogs of 6.beta.-aminopenicillanic acid and biologically active derivatives thereof can be formed from esters of 6-oxopenicillanic acid. For example, 6.beta.-phenoxyacetoxy-penicillanic acid--an oxygen analog of penicillin V and 6.beta.-phenoxyacetylmethylpenicillanic acid--a carbon analog of penicillin V, may be formed from an ester of 6-oxopenicillanate. The ester of 6-oxopenicillanic acid is formed by a diiospropyl carbodiimide/dimethyl sulfoxide oxidation of the corresponding ester of 6.alpha.-hydroxypenicillanic acid. The oxygen analogs are formed by reducing the ester of 6-oxopenicillanic acid to the corresponding 6.beta.-hydroxypenicillanate and then forming the desired analog by acylation. The carbon analogs are formed by a Wittig reaction of the ester of 6-oxopenicillanic acid with a suitable acylmethylenetriphenylphosphorane followed by saturation of the newly formed double bond and removal of the protective ester group.
    Type: Grant
    Filed: September 27, 1978
    Date of Patent: August 4, 1981
    Assignee: Massachusetts Institute of Technology
    Inventors: John C. Sheehan, Young S. Lo
  • Patent number: 4282361
    Abstract: An improved synthesis is disclosed for 7-alkylamino-3-methylpyrazolo[4,3-d]pyrimidines, which are known to be potent cytokinin antagonists.
    Type: Grant
    Filed: March 16, 1978
    Date of Patent: August 4, 1981
    Assignee: Massachusetts Institute of Technology
    Inventors: Sidney M. Hecht, Ulrich Jordis
  • Patent number: 4281119
    Abstract: An apparatus and process useful in direct fluorination of a variety of compositions, as well as the fluorinated compositions themselves, are disclosed.The apparatus comprises a cryogenic zone reactor, such as a packed column reactor, suitably divided into a plurality of independently controllable cryogenic temperature zones. Means are also provided to introduce a reactant to be fluorinated as well as to introduce a mixture of fluorine gas and an inert gas.New fluorinated compounds are also disclosed. These include: perfluoro-2-methoxyethyl ether; perfluoro-1,4-dioxane; perfluoro-2,5-diketohexane; perfluorohexamethylethane; and monohydropentadecafluoroadamantane.Additionally, new syntheses for trifluoroacetic acid, a commercially significant bulk chemical, are disclosed. One synthesis comprises producing perfluoroethyl acetate by direct fluorination using a cryogenic zone reactor, followed by hydrolysis of perfluoroethyl acetate. Two moles of the acid are produced for each mole of ester.
    Type: Grant
    Filed: June 23, 1976
    Date of Patent: July 28, 1981
    Assignee: Massachusetts Institute of Technology
    Inventors: Richard J. Lagow, James L. Adcock, Norma J. Maraschin
  • Patent number: 4280954
    Abstract: Composite materials are disclosed which are formed by contacting collagen with a mucopolysaccharide and subsequently covalently crosslinking the resultant polymer. These composite materials have a balance of mechanical, chemical and physiological properties which make them useful in surgical sutures and prostheses of controlled biodegradability (resorption) and controlled ability to prevent development of a foreign body reaction, and many are also useful in applications in which blood compatibility is required.
    Type: Grant
    Filed: April 16, 1979
    Date of Patent: July 28, 1981
    Assignee: Massachusetts Institute of Technology
    Inventors: Ioannis V. Yannas, Philip L. Gordon, Chor Huang, Frederick H. Silver, John F. Burke
  • Patent number: 4281312
    Abstract: A system wherein an image such as, for example, unscreened artwork is divided into sub-images each of which is digitized and is then represented by the digital code of a pattern that closely matches the sub-image. Thereafter, the image is reconstructed by reproducing the pattern equivalents of the sub-images to form a composite image.
    Type: Grant
    Filed: November 4, 1975
    Date of Patent: July 28, 1981
    Assignee: Massachusetts Institute of Technology
    Inventor: Donald R. Knudson
  • Patent number: 4279843
    Abstract: Uniform sized particles of a ceramic or metal composition are formed by impinging a liquid stream of the composition upon at least one liquid stream of a second ceramic or metal which has a lower melting point than that of the particles. The impingement causes the liquid precursor to the particles to form small eddies which become solidified through heat loss to the other liquid stream. The temperature of the mixture is maintained so that the particles remain solidified while the other liquid stream(s) remain liquid. The solid particles then are separated from the liquid.
    Type: Grant
    Filed: March 26, 1980
    Date of Patent: July 21, 1981
    Assignee: Massachusetts Institute of Technology
    Inventor: Nam P. Suh
  • Patent number: 4278622
    Abstract: Fine grain metal, ceramic or metal-ceramic or metal-polymer compositions are formed by impinging at least two liquid streams of metal, ceramic and/or polymer, upon each other to form a turbulent mixture having small eddies. At least a portion of the mixture is frozen quickly before grain and/or cell growth in the mixed components occurs to any substantial extent. The resultant product can be a solid or a slurry.
    Type: Grant
    Filed: February 26, 1980
    Date of Patent: July 14, 1981
    Assignee: Massachusetts Institute of Technology
    Inventor: Nam P. Suh
  • Patent number: 4274737
    Abstract: Lens testing charts using a vernier pattern, a sawtooth pattern, and a sinusoidally varying reflectance pattern are described and are used in conjunction with a lens under test to be focussed by said lens onto suitable high contrast film to provide an image from which the quality of the lens may be determined.
    Type: Grant
    Filed: October 19, 1979
    Date of Patent: June 23, 1981
    Assignee: Massachusetts Institute of Technology
    Inventor: Bradford Howland