Patents Assigned to Tohoku University
  • Patent number: 4759214
    Abstract: The disclosed method introduces a pressure effectivity factor h, so as to continuously determine fracture toughness K.sub.IC of rock during core boring by using the equation ofK.sub.IC =0.346.sqroot.N/.epsilon.L.multidot.hQ/B; andhere, N is the revolving speed of a coring bit, Q is the pressure supplied to it, L is its drilling speed, B is the width of its bit face, and .epsilon. is the number of rows of its face stones. The pressure effectivity factor h is predetermined by using both a core whose fracture toughness is measured by the ISRM (International Society for Rock Mechanics) method and the above constants which are used in boring the core.
    Type: Grant
    Filed: February 19, 1987
    Date of Patent: July 26, 1988
    Assignee: Tohoku University
    Inventors: Hideki Sekine, Hideaki Takahashi, Hiroyuki Abe
  • Patent number: 4742378
    Abstract: A junction-type semiconductor light emitting device comprising a plate portion, a column formed on one surface of the plate portion and electrodes provided on each of opposite surfaces of the plate portion including the column wall, the column having a pn junction formed therein and extending perpendicular to the plate portion, the plate portion having a pn junction formed therein and extending in parallel with the plate portion, these pn junctions being connected with each other, the current density through the pn junction in the column being larger than that through the pn junction in the plate portion under the application of a predetermined voltage across the electrodes, so as to facilitate the continuous oscillation of this light emitting device at room temperature with the resultant light emission through the column. The light emitting device can be readily arranged in matrix and readily integrated in high degree.
    Type: Grant
    Filed: September 30, 1985
    Date of Patent: May 3, 1988
    Assignee: Japan Represented by President of Tohoku University
    Inventors: Hiromasa Ito, Humio Inaba
  • Patent number: 4665984
    Abstract: Earth's crustal stress is measured by drilling a bore-hole in rock body, producing a longitudinal crack at a selected portion thereof with or without a natural traverse crack through intermittent application of hydraulic pressure thereat while measuring the pressure at different stages of crack production, producing an artificial traverse cracks through the use of a prenotch, determining orientations of the cracks thus produced by inspecting the bore-hole surface conditions, and numerically analyzing the crack orientations and the pressures at different stages of crack production.
    Type: Grant
    Filed: August 14, 1986
    Date of Patent: May 19, 1987
    Assignee: Tohoku University
    Inventors: Kazuo Hayashi, Tetsuo Shoji, Hiroaki Niitsuma, Hideaki Takahashi, Hiroyuki Abe
  • Patent number: 4659786
    Abstract: Polyester-polysiloxane block copolymers for dental uses are disclosed as low modulus thermoplastic elastomers. The copolymers comprise polycaprolactone residues and poly(dimethylsiloxane) .alpha.,.omega.-diol residues which are linked by ether bonds. The compounds exhibit the property of plasticity by heating and the property of original rubber elasticity by cooling again to room temperature.
    Type: Grant
    Filed: June 3, 1985
    Date of Patent: April 21, 1987
    Assignee: Tohoku University
    Inventors: Michio Kawakami, Yoshima Araki, Kenkichi Murakami, Hidetoshi Oikawa, Michio Nakanishi, Makoto Hosotani
  • Patent number: 4523966
    Abstract: The disclosed process produces a silicon ribbon wafer with a p-n junction, by melting a raw silicon material, ejecting the molten silicon material onto a rotary cooling member so as to produce a silicon ribbon wafer through super-rapid cooling, and applying an impurity element whose polarity is opposite to that of the raw silicon material onto the thus formed silicon ribbon wafer at a temperature of not lower than 600.degree. C. and cooled from said temperature, whereby a p-n junction is formed in the silicon ribbon wafer simultaneously with the production of the fully solidified silicon ribbon wafer.
    Type: Grant
    Filed: September 13, 1984
    Date of Patent: June 18, 1985
    Assignee: Tohoku University
    Inventors: Noboru Tsuya, Kenichi Arai, Toshio Takeuchi
  • Patent number: 4521681
    Abstract: An optical function semiconductor device formed by opto-electrical loop coupling of a light emitting diode and a photodetector, the latter of which receives a part of an output light of the former controlled by an output current thereof, can be readily miniaturized and integrated as a fundamental function active device self-containing a light source and presenting various useful novel functions of the optoelectronic technology between the external input and the output lights.
    Type: Grant
    Filed: May 24, 1982
    Date of Patent: June 4, 1985
    Assignee: Tohoku University
    Inventors: Humio Inaba, Hiromasa Ito, Yoh Ogawa
  • Patent number: 4483004
    Abstract: A laser functional device formed by photoelectric direct loop coupling of a laser diode and a photodetector, the latter of which receives a part of an output light of the former together with an external input light and excites the former by an output current thereof, can be easily miniaturized and integrated as a fundamental function active device self-containing a light source and presenting various useful functions of the optoelectronic technology between the external input and the output lights.
    Type: Grant
    Filed: March 25, 1982
    Date of Patent: November 13, 1984
    Assignee: Tohoku University
    Inventors: Humio Inaba, Hiromasa Ito, Yoh Ogawa
  • Patent number: 4403022
    Abstract: A chemically modified photoelectrochemical cell including at least one cathode and a plurality of anodes, at least said plurality of anodes being constituted with a semiconductor, each of said plurality of anodes being formed by fixing through covalent bonds molecules of at least one sensitizer dye on the surface of a light-transmissible flat plate of an n-type semiconductor or a light-transmissible flat plate covered with a thin film of an n-type semiconductor, and said plurality of anodes being disposed parallelly to each other and in the form of layers in an electrolyte solution, together with said at least one cathode. Thus, since this photoelectrochemical cell can convert photoenergy of a longer wavelength to electric energy with a high efficiency by making the use of the dye sensitization effect, sufficient practical utility to the photodevices is obtained.
    Type: Grant
    Filed: January 2, 1981
    Date of Patent: September 6, 1983
    Assignee: The President of Tohoku University
    Inventors: Tetsuo Osa, Masamichi Fujihira
  • Patent number: 4389165
    Abstract: An ion pump for producing an ultrahigh degree of vacuum comprising a space formed between a first perforated flat plate-shaped electrode and a second flat plate-shaped electrode and having a high frequency electric source connected between the first and second electrodes, said space being operative to induce multipactor effect between said first and second electrodes, and an ionization space adjacent to one of said first and second electrodes and formed between a first perforated getter electrode and a second getter electrode applied with a negative potential, said ionization space being operative to cause the moving electrons produced by the multipactor effect to collide with gas molecules and ionize the latter.
    Type: Grant
    Filed: September 26, 1980
    Date of Patent: June 21, 1983
    Assignee: Tohoku University
    Inventors: Shoichi Ono, Kuniyoshi Yokoo
  • Patent number: 4340568
    Abstract: A super hard-highly pure silicon nitride includes a preferentially oriented crystalline silicon nitride having a grain size of 1-50 .mu.m and a micro Vickers hardness of 5,000 kg/mm.sup.2 under a load of 100 g, a finely grained crystalline silicon nitride having an average grain size of less than 1 .mu.m and a micro Vickers hardness of 3,500 kg/mm.sup.2 under a load of 100 g, and an amorphous silicon nitride having a micro Vickers hardness of 2,200 kg/mm.sup.2 under a load of 100 g, and is produced by blowing a nitrogen depositing source and a silicon depositing source on a substrate heated at 500.degree.-1,900.degree. C. with a blowpipe composed of a pipe assembly wherein a first pipe for the nitrogen depositing source is surrounded with a second pipe for the silicon depositing source and the distance from an opening end of the first pipe to the substrate is shorter than the distance from an opening end of the second pipe to the substrate.
    Type: Grant
    Filed: January 28, 1980
    Date of Patent: July 20, 1982
    Assignee: The Research Institute for Iron, Steel and Other Metals of the Tohoku University
    Inventors: Toshio Hirai, Koichi Niihara
  • Patent number: 4312923
    Abstract: A super hard-highly pure silicon nitride includes a preferentially oriented crystalline silicon nitride having a grain size of 1-50 .mu.m and a micro Vickers hardness of 3,000 kg/mm.sup.2 under a load of 100 g, a finely grained crystalline silicon nitride having an average grain size of less than 1 .mu.m and a micro Vickers hardness of 3,500 kg/mm.sup.2 under a load of 100 g, and an amorphous silicon nitride having a micro Vickers hardness of 2,200 kg/mm.sup.2 under a load of 100 g, and is produced by blowing a nitrogen depositing source and a silicon depositing source on a substrate heated at 500.degree.-1,900.degree. C. with a blowpipe composed of a pipe assembly wherein a first pipe for the nitrogen depositing source is surrounded with a second pipe for the silicon depositing source and the distance from an opening end of the first pipe to the substrate is shorter than the distance from an opening end of the second pipe to the substrate.
    Type: Grant
    Filed: February 11, 1980
    Date of Patent: January 26, 1982
    Assignee: The Research Institute for Iron, Steel and Other Metals of the Tohoku University
    Inventors: Toshio Hirai, Koichi Nihara
  • Patent number: 4312921
    Abstract: A super hard-highly pure silicon nitride includes a preferentially oriented crystalline silicon nitride having a grain size of 1-50 .mu.m and a micro Vickers hardness of 3,000 kg/mm.sup.2 under a load of 100 g, a finely grained crystalline silicon nitride having an average grain size of less than 1 .mu.m and a micro Vickers hardness of 3,500 kg/mm.sup.2 under a load of 100 g, and an amorphous silicon nitride having a micro Vickers hardness of 2,200 kg/mm.sup.2 under a load of 100 g, and is produced by blowing a nitrogen depositing source and a silicon depositing source on a substrate heated at 500.degree.-1,900.degree. C. with a blowpipe composed of a pipe assembly wherein a first pipe for the nitrogen depositing source is surrounded with a second pipe for the silicon depositing source and the distance from an opening end of the first pipe to the substrate is shorter than the distance from an opening end of the second pipe to the substrate.
    Type: Grant
    Filed: July 21, 1978
    Date of Patent: January 26, 1982
    Assignee: The Research Institute for Iron, Steel and Other Metals of the Tohoku University
    Inventors: Toshio Hirai, Koichi Niihara
  • Patent number: 4312924
    Abstract: A super hard-highly pure silicon nitride includes a preferentially oriented crystalline silicon nitride having a grain size of 1-50 .mu.m and a micro Vickers hardness of 3,000 kg/mm.sup.2 under a load of 100 g, a finely grained crystalline silicon nitride having an average grain size of less than 1 .mu.m and a micro Vickers hardness of 3,500 kg/mm.sup.2 under a load of 100 g, and an amorphous silicon nitride having a micro Vickers hardness of 2,200 kg/mm.sup.2 under a load of 100 g, and is produced by blowing a nitrogen depositing source and a silicon depositing source on a substrate heated at 500.degree.-1,900.degree. C. with a blowpipe composed of a pipe assembly wherein a first pipe for the nitrogen depositing source is surrounded with the second pipe for silicon depositing source and the distance from an opening end of the first pipe to the substrate is shorter than a distance from an opening end of the second pipe to the substrate.
    Type: Grant
    Filed: March 11, 1980
    Date of Patent: January 26, 1982
    Assignee: The Research Institute for Iron, Steel and Other Metals of the Tohoku University
    Inventors: Toshio Hirai, Koichi Niihara
  • Patent number: 4279689
    Abstract: A super hard-highly pure silicon nitride includes a preferentially oriented crystalline silicon nitride having a grain size of 1-50 .mu.m and a micro Vickers hardness of 3,000 kg/mm.sup.2 under a load of 100 g, a finely grained crystalline silicon nitride having an average grain size of less than 1 .mu.m and a micro Vickers hardness of 3,500 kg/mm.sup.2 under a load of 100 g, and an amorphous silicon nitride having a micro Vickers hardness of 2,200 kg/mm.sup.2 under a load of 100 g, and is produced by blowing a nitrogen depositing source and a silicon depositing source on a substrate heated at 500.degree.-1,900.degree. C. with a blowpipe composed of a pipe assembly wherein a first pipe for the nitrogen depositing source is surrounded with a second pipe for the silicon depositing source and the distance from an opening end of the first pipe to the substrate is shorter than the distance from an opening end of the second pipe to the substrate.
    Type: Grant
    Filed: July 21, 1978
    Date of Patent: July 21, 1981
    Assignee: The Research Institute for Iron, Steel and Other Metals of the Tohoku University
    Inventors: Toshio Hirai, Koichi Niihara
  • Patent number: 4255501
    Abstract: An internally reflective, dye sensitized, wet-type photocell suitably adaptable as a photosensitive element or a solar cell, comprising anodes and cathodes immersed in an electrolyte solution containing a reduction-oxidation agent and dye sensitizers. Each of the anodes is provided with a light inlet end adapted for the introduction of light into the interior thereof, and a surface layer portion of an n-type semiconductive substance so that light introduced through the light inlet end to the interior of the anode is reflected a plurality of times so as to absorb the energy of the light to generate a voltage. Thus, since the dye sensitizing effect is efficiently utilized, the photocell enables the conversion efficiency of photo energy to electric energy to improve sufficiently for practical uses.
    Type: Grant
    Filed: October 25, 1979
    Date of Patent: March 10, 1981
    Assignee: President of Tohoku University
    Inventors: Tetsuo Osa, Masamichi Fujihira
  • Patent number: 4224296
    Abstract: A super hard-highly pure silicon nitride includes a preferentially oriented crystalline silicon nitride having a grain size of 1-50 .mu.m and a micro Vickers hardness of 3,000 kg/mm.sup.2 under a load of 100 g, a finely grained crystalline silicon nitride having an average grain size of less than 1 .mu.m and a micro Vickers hardness of 3,500 kg/mm.sup.2 under a load of 100 g, and an amorphous silicon nitride having a micro Vickers hardness of 2,200 kg/mm.sup.2 under a load of 100 g, and is produced by blowing a nitrogen depositing source and a silicon depositing source on a substrate heated at 500.degree.-1,900.degree. C. with a blowpipe composed of a pipe assembly wherein a first pipe for the nitrogen depositing source is surrounded with a second pipe for the silicon depositing source and the distance from an opening end of the first pipe to the substrate is shorter than the distance from an opening end of the second pipe to the substrate.
    Type: Grant
    Filed: July 21, 1978
    Date of Patent: September 23, 1980
    Assignee: The Research Institute for Iron, Steel and Other Metals of the Tohoku University
    Inventors: Toshio Hirai, Koichi Niihara
  • Patent number: 4164528
    Abstract: Metal nitride sintered moldings are produced by mixing metal nitride powders with an organosilicon compound or an organosilicon high molecular weight compound as a binder, molding the mixture into a desired shape and heating the formed molding under a non-oxidizing atmosphere to sinter the metal nitride powders.
    Type: Grant
    Filed: October 8, 1976
    Date of Patent: August 14, 1979
    Assignee: The Research Institute for Iron, Steel and Other Metals of the Tohoku University
    Inventors: Seishi Yajima, Josaburo Hayashi, Mamoru Omori, Hideo Kayano, Masaaki Hamano
  • Patent number: 4159259
    Abstract: Organosilicon high molecular weight compounds containing silicon and carbon as the main skeleton components and organosilicon high molecular weight compounds containing silicon and carbon as the main skeleton components and 0.01-20% by weight of at least one foreign element other than silicon, carbon, hydrogen and oxygen have a number average molecular weight of 500-30,000, and intrinsic viscosity of 0.01-1.50 and a silicon carbide residual amount of not less than 40% by weight after baked at a temperature of 800.degree.-1,500.degree. C. in a non-oxidizing atmosphere and are useful for the production of silicon carbide moldings.
    Type: Grant
    Filed: February 18, 1977
    Date of Patent: June 26, 1979
    Assignee: The Research Institute for Iron, Steel and Other Metals of the Tohoku University
    Inventors: Seishi Yajima, Josaburo Hayashi, Mamoru Omori
  • Patent number: 4158687
    Abstract: A heat-resistant composite material reinforced with continuous silicon carbide fibers is produced by forming a powdery ceramics matrix and the fibers into a composite, and pressing and heating the composite into a sintered composite. The composite material is excellent in the mechanical strength at a high temperature, heat resistance, oxidation resistance and corrosion resistance.
    Type: Grant
    Filed: October 18, 1976
    Date of Patent: June 19, 1979
    Assignee: The Research Institute For Iron, Steel and Other Metals of the Tohoku University
    Inventors: Seishi Yajima, Josaburo Hayashi, Mamoru Omori, Hideo Kayano, Masaaki Hamano
  • Patent number: 4147538
    Abstract: Cobalt or cobalt alloy composite materials reinforced with continuous silicon carbide fibers, which have a high tensile strength, a low elongation, a high Young modulus and a high tensile strength at a high temperature, are produced by filling spaces in piles of the continuous silicon carbide fibers containing 0.01%-30% by weight of free carbon with melted or powdery metallic cobalt or cobalt alloy and integrating the said fibers with the said metal.
    Type: Grant
    Filed: January 21, 1977
    Date of Patent: April 3, 1979
    Assignee: The Research Institute for Iron, Steel and other Metals of the Tohoku University
    Inventors: Seishi Yajima, Hideo Kayano, Chiaki Asada, Makoto Saito