Patents by Inventor Yoshiyuki Shirakawa

Yoshiyuki Shirakawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9488602
    Abstract: A radioactive substance detection device that detects a radioactive substance being present in a specified direction. A radiation detection element having a thickness that stops and detects a characteristic X-ray arriving from a radioactive substance being present in the specified direction that radiates both gamma rays and the characteristic X-rays, and allows the gamma ray arriving from the radioactive substance to pass through. A screening body having a thickness that screens out characteristic X-rays of radiation which arrives from directions other than the specified direction and allows gamma rays of radiation which arrives from directions other than the specified direction to pass through.
    Type: Grant
    Filed: January 12, 2013
    Date of Patent: November 8, 2016
    Assignee: National Institutes for Quantum and Radiological Science and Technology
    Inventors: Shingo Kobayashi, Yukio Uchihori, Yoshiyuki Shirakawa
  • Publication number: 20140299784
    Abstract: A radioactive substance detection device that detects a radioactive substance being present in a specified direction. A radiation detection element having a thickness that stops and detects a characteristic X-ray arriving from a radioactive substance being present in the specified direction that radiates both gamma rays and the characteristic X-rays, and allows the gamma ray arriving from the radioactive substance to pass through. A screening body having a thickness that screens out characteristic X-rays of radiation which arrives from directions other than the specified direction and allows gamma rays of radiation which arrives from directions other than the specified direction to pass through.
    Type: Application
    Filed: January 12, 2013
    Publication date: October 9, 2014
    Applicant: National Institute of Radiological Sciences
    Inventors: Shingo Kobayashi, Yukio Uchihori, Yoshiyuki Shirakawa
  • Publication number: 20140166890
    Abstract: A resin for scintillators having high radiation sensitivity, which is obtained without using a wavelength conversion agent. The resin for the scintillator of a radiation detector contains a polyester having a unit represented by the following formula (1). (In the above formula (1), Ar is a naphthalenediyl group or an anthracenediyl group all of which may be substituted by an alkyl group having 1 to 6 carbon atoms or a halogen atom. X is an aliphatic hydrocarbon group having 2 to 20 carbon atoms, an alicyclic hydrocarbon group having 2 to 20 carbon atoms or an aromatic hydrocarbon group having 5 to 20 carbon atoms all of which may be substituted by an alkyl group having 1 to 6 carbon atoms or a halogen atom.
    Type: Application
    Filed: February 2, 2012
    Publication date: June 19, 2014
    Applicants: NATIONAL INSTITUTE OF RADIOLOGICAL SCIENCES, TEIJIN LIMITED
    Inventors: Hisayoshi Shimizu, Fumio Murakawa, Zenichiro Shidara, Hidehito Nakamura, Yoshiyuki Shirakawa
  • Patent number: 8106362
    Abstract: A surface contamination examining device includes a radiation detector 11 and an arithmetic/display device 13 for displaying radiation intensity in form of a counting rate. The arithmetic/display device has a boundary detecting device 10 that detects the boundary of contamination 14 of an object to be measured by a radioactive material while the radiation detector moves along a surface 18 of the object to be measured.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: January 31, 2012
    Assignee: National Institute of Radiological Sciences
    Inventor: Yoshiyuki Shirakawa
  • Patent number: 7735658
    Abstract: A classification apparatus including a magnetic stirrer composed of main body (1) and rotor (2) and, arranged on the main body of the magnetic stirrer, classification tube (3). The interior of the classification tube is provided with classification compartments (A-E) partitioned from each other by divider plates (5a-5b). The lowermost classification compartment (A) is furnished with gas emission conduit (7). In the classification compartment (A), the rotor (2) of the magnetic stirrer is arranged. From gas supply source (8), a high-pressure gas is fed into the gas emission conduit. By means of the gas emitted from the gas emission conduit, a vortex flow rising from the lowermost classification compartment sequentially toward higher classification compartments is generated in the classification tube.
    Type: Grant
    Filed: January 23, 2007
    Date of Patent: June 15, 2010
    Assignees: The Doshisha, Kyoto University, Fukujuen Co., Ltd.
    Inventors: Jusuke Hidaka, Shinzo Yoshikado, Yoshiyuki Shirakawa, Yoshiaki Ito, Kiyoshi Hayakawa, Yuuko Watanabe
  • Patent number: 7734447
    Abstract: A radiation measuring device capable of identifying the incident direction of a radiation ray and energy (segmentation). The directivity characteristics of a plurality of detectors are different from each other. A plurality of energy segmentations are set respectively for a plurality of spectra corresponding to a plurality of detectors, and actual measurement ratio information (a plurality of actual measurement counting ratios) expressing the mutual ratio between integrated counting values for each energy segmentation is computed. The actual measurement ratio information is checked against a plurality of response functions, and, when the compatibility relation between specific actual measurement ratio information and specific theoretical ratio information is found, the incident direction of a radiation ray and an energy segmentation are identified based on that relation.
    Type: Grant
    Filed: November 27, 2006
    Date of Patent: June 8, 2010
    Assignees: National Institute of Radiological Science, Aloka Co., Ltd.
    Inventors: Yoshiyuki Shirakawa, Yusuke Kobayashi, Toshiya Yamano
  • Patent number: 7723696
    Abstract: In a radiation detector, a response is approximated as a primary delay system, and when a time constant T indicating the characteristic of the response is known, a final response value N0 is forecasted from dose rates or counting rates N1 and N2 of two points in the initial or middle stage of response. When the time constant T is unknown, the final response value N0 is forecasted from dose rates or counting rates N1, N2, and N3 of three points in the initial or middle stage of response. Simultaneously, a time constant is obtained and the soundness of the radiation detector is also evaluated. Thereby, a dose rate in an existence field of radiation or a counting rate in an existence field of radioactive materials is quickly and accurately forecasted, whereby the measurement time is shortened.
    Type: Grant
    Filed: February 16, 2006
    Date of Patent: May 25, 2010
    Assignees: National Institute of Radiological Sciences, Amano & Associates, Inc.
    Inventors: Yoshiyuki Shirakawa, Hiro Amano
  • Patent number: 7655912
    Abstract: A direction finding radiation detector for detecting the direction of incidence of radioactive rays, comprising: a plurality of scintillators (41, 42, 43) (101, 102, 103) made of the same material, being arranged to overlap circumferentially at least in part so that they are shadowed by each other from radioactive rays incident in circumferential directions and so that light emitted from one of the scintillators is not incident on the other scintillators; and photoreceptor devices (51, 52, 53) (111, 112, 113) having light receiving surfaces optically coupled to the respective scintillators, wherein a combination of proportions of radioactive rays incident directly on the respective scintillators and radioactive rays incident indirectly thereon, being shadowed by the other scintillators, varies with the direction of incidence circumferentially.
    Type: Grant
    Filed: January 10, 2006
    Date of Patent: February 2, 2010
    Assignees: National Institute of Radiological Sciences, Aloka Co., Ltd.
    Inventors: Yoshiyuki Shirakawa, Toshiya Yamano
  • Publication number: 20090294669
    Abstract: A surface contamination examining device includes a radiation detector 11 and an arithmetic/display device 13 for displaying radiation intensity in form of a counting rate. The arithmetic/display device has a boundary detecting device 10 that detects the boundary of contamination 14 of an object to be measured by a radioactive material while the radiation detector moves along a surface 18 of the object to be measured.
    Type: Application
    Filed: March 30, 2007
    Publication date: December 3, 2009
    Applicant: NATIONAL INSTITUTE OF RADIOLOGICAL SCIENCES
    Inventor: Yoshiyuki Shirakawa
  • Publication number: 20090271143
    Abstract: A radiation measuring device capable of identifying the incident direction of a radiation ray and energy (segmentation) The directivity characteristics of a plurality of detectors are different from each other. A plurality of energy segmentations are set respectively for a plurality of spectra corresponding to a plurality of detectors, and actual measurement ratio information (a plurality of actual measurement counting ratios) expressing the mutual ratio between integrated counting values for each energy segmentation is computed. The actual measurement ratio information is checked against a plurality of response functions, and, when the compatibility relation between specific actual measurement ratio information and specific theoretical ratio information is found, the incident direction of a radiation ray and an energy segmentation are identified based on that relation.
    Type: Application
    Filed: November 27, 2006
    Publication date: October 29, 2009
    Applicants: NATIONAL INSTITUTE OF RADIOLOGICAL SCIENCES, ALOKA CO., LTD.
    Inventors: Yoshiyuki Shirakawa, Yusuke Kobayashi, Toshiya Yamano
  • Publication number: 20090078619
    Abstract: A classification apparatus including a magnetic stirrer composed of main body (1) and rotor (2) and, arranged on the main body of the magnetic stirrer, classification tube (3). The interior of the classification tube is provided with classification compartments (A-E) partitioned from each other by divider plates (5a-5b). The lowermost classification compartment (A) is furnished with gas emission conduit (7). In the classification compartment (A), the rotor (2) of the magnetic stirrer is arranged. From gas supply source (8), a high-pressure gas is fed into the gas emission conduit. By means of the gas emitted from the gas emission conduit, a vortex flow rising from the lowermost classification compartment sequentially toward higher classification compartments is generated in the classification tube.
    Type: Application
    Filed: January 23, 2007
    Publication date: March 26, 2009
    Applicants: THE DOSHISHA, Kyoto University, Fukujuen Co., Ltd.
    Inventors: Jusuke Hidaka, Shinzo Yoshikado, Yoshiyuki Shirakawa, Yoshiaki Ito, Kiyoshi Hayakawa, Yuuko Watanabe
  • Publication number: 20090035439
    Abstract: A method capable of manufacturing, by using a ball mill apparatus, powdered tea having the same quality as that manufactured by using a millstone. By using the ball mill apparatus having synthetic resin pots, a powdered tea material and synthetic resin balls are sealed in the pot, and the pot is revolved or revolved and rotated on its axis to crush the powdered tea material.
    Type: Application
    Filed: March 31, 2006
    Publication date: February 5, 2009
    Inventors: Jusuke Hidaka, Shinzo Yoshikado, Yoshiyuki Shirakawa, Yoshiaki Ito, Kiyoshi Hayakawa, Yuuko Watanabe
  • Publication number: 20080272305
    Abstract: In a radiation detector, a response is approximated as a primary delay system, and when a time constant T indicating the characteristic of the response is known, a final response value N0 is forecasted from dose rates or counting rates N1 and N2 of two points in the initial or middle stage of response. When the time constant T is unknown, the final response value N0 is forecasted from dose rates or counting rates N1, N2, and N3 of three points in the initial or middle stage of response. Simultaneously, a time constant is obtained and the soundness of the radiation detector is also evaluated. Thereby, a dose rate in an existence field of radiation or a counting rate in an existence field of radioactive materials is quickly and accurately forecasted, whereby the measurement time is shortened.
    Type: Application
    Filed: February 16, 2006
    Publication date: November 6, 2008
    Applicants: National Institute of Radiological Sciences, Amano & Associates, Inc.
    Inventors: Yoshiyuki Shirakawa, Hiro Amano
  • Publication number: 20070221854
    Abstract: A direction finding radiation detector for detecting the direction of incidence of radioactive rays, comprising: a plurality of scintillators (41, 42, 43) (101, 102, 103) made of the same material, being arranged to overlap circumferentially at least in part so that they are shadowed by each other from radioactive rays incident in circumferential directions and so that light emitted from one of the scintillators is not incident on the other scintillators; and photoreceptor devices (51, 52, 53) (111, 112, 113) having light receiving surfaces optically coupled to the respective scintillators, wherein a combination of proportions of radioactive rays incident directly on the respective scintillators and radioactive rays incident indirectly thereon, being shadowed by the other scintillators, varies with the direction of incidence circumferentially.
    Type: Application
    Filed: January 10, 2006
    Publication date: September 27, 2007
    Applicant: Aloka Co., Ltd
    Inventor: Yoshiyuki Shirakawa