Patents by Inventor Liukang Xu

Liukang Xu 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: 11460480
    Abstract: Systems and methods for measuring turbulent gas flux using high-speed vertical wind speed measurements (e.g., on the order of 5-10 Hz or more frequently) and low-speed gas content measurements (e.g., on the order of 5 Hz or less frequently), without the need for the sophisticated and expensive high-speed hardware to separate gas samples (e.g., into accumulation bags) according to updrafts and downdrafts. A time series of high-speed vertical wind speed data is used as a guide to distinguish between updrafts and downdrafts. When vertical wind speed is upward (updraft), the low-speed gas content is recorded into a data structure in one location, or marked with one flag. When vertical wind speed is downward (downdraft), the low-speed gas content is recorded into a different location, or marked with a different flag. Eddy Accumulation or Relaxed Eddy Accumulation computations can be performed using the stored gas content data to determine gas flux.
    Type: Grant
    Filed: August 8, 2018
    Date of Patent: October 4, 2022
    Assignee: Li-Cor, Inc.
    Inventors: George G. Burba, Dayle McDermitt, Xiaomao Lin, Liukang Xu, Dave Johnson
  • Publication number: 20180372770
    Abstract: Systems and methods for measuring turbulent gas flux using high-speed vertical wind speed measurements (e.g., on the order of 5-10 Hz or more frequently) and low-speed gas content measurements (e.g., on the order of 5 Hz or less frequently), without the need for the sophisticated and expensive high-speed hardware to separate gas samples (e.g., into accumulation bags) according to updrafts and downdrafts. A time series of high-speed vertical wind speed data is used as a guide to distinguish between updrafts and downdrafts. When vertical wind speed is upward (updraft), the low-speed gas content is recorded into a data structure in one location, or marked with one flag. When vertical wind speed is downward (downdraft), the low-speed gas content is recorded into a different location, or marked with a different flag. Eddy Accumulation or Relaxed Eddy Accumulation computations can be performed using the stored gas content data to determine gas flux.
    Type: Application
    Filed: August 8, 2018
    Publication date: December 27, 2018
    Inventors: George G. Burba, Dayle McDermitt, Xiaomao Lin, Liukang Xu, Dave Johnson
  • Patent number: 10060942
    Abstract: Systems and methods for measuring turbulent gas flux using high-speed vertical wind speed measurements (e.g., on the order of 5-10 Hz or more frequently) and low-speed gas content measurements (e.g., on the order of 5 Hz or less frequently), without the need for the sophisticated and expensive high-speed hardware to separate gas samples (e.g., into accumulation bags) according to updrafts and downdrafts. A time series of high-speed vertical wind speed data is used as a guide to distinguish between updrafts and downdrafts. When vertical wind speed is upward (updraft), the low-speed gas content is recorded into a data structure in one location, or marked with one flag. When vertical wind speed is downward (downdraft), the low-speed gas content is recorded into a different location, or marked with a different flag. Eddy Accumulation or Relaxed Eddy Accumulation computations can be performed using the stored gas content data to determine gas flux.
    Type: Grant
    Filed: April 6, 2012
    Date of Patent: August 28, 2018
    Assignee: Li-Cor, Inc.
    Inventors: George G. Burba, Dayle McDermitt, Xiaomao Lin, Liukang Xu, Dave Johnson
  • Publication number: 20130268208
    Abstract: Systems and methods for measuring turbulent gas flux using high-speed vertical wind speed measurements (e.g., on the order of 5-10 Hz or more frequently) and low-speed gas content measurements (e.g., on the order of 5 Hz or less frequently), without the need for the sophisticated and expensive high-speed hardware to separate gas samples (e.g., into accumulation bags) according to updrafts and downdrafts. A time series of high-speed vertical wind speed data is used as a guide to distinguish between updrafts and downdrafts. When vertical wind speed is upward (updraft), the low-speed gas content is recorded into a data structure in one location, or marked with one flag. When vertical wind speed is downward (downdraft), the low-speed gas content is recorded into a different location, or marked with a different flag. Eddy Accumulation or Relaxed Eddy Accumulation computations can be performed using the stored gas content data to determine gas flux.
    Type: Application
    Filed: April 6, 2012
    Publication date: October 10, 2013
    Applicant: LI-COR, Inc.
    Inventors: George G. Burba, Dayle McDermitt, Xiaomao Lin, Liukang Xu, Dave Johnson
  • Patent number: 8433525
    Abstract: A system and method to obtain correct gas density and flux measurements using (i) gas analyzer (open-path, or closed-path gas analyzers with short intake tube, or any combination of the two); (ii) fast temperature or sensible heat flux measurement device (such as, fine-wire thermocouple, sonic anemometer, or any other device providing fast accurate gas temperature measurements); (iii) fast air water content or latent heat flux measurement device (such as, hygrometer, NDIR analyzer, any other device providing fast accurate gas water content measurements); (iv) vertical wind or sampling device (such as sonic anemometer, scintillometer, or fast solenoid valve, etc.) and (v) algorithms in accordance with the present invention to compute the corrected gas flux, compensated for T-P effects. In case when water factor in T-P effects is negligible, the fast air water content or latent heat flux measurement device (item iii in last paragraph) can be excluded.
    Type: Grant
    Filed: April 12, 2011
    Date of Patent: April 30, 2013
    Assignee: LI-COR, Inc.
    Inventors: George Burba, Dayle McDermitt, Anatoly Komissarov, Tyler G. Anderson, Liukang Xu, Bradley A. Riensche
  • Publication number: 20110270534
    Abstract: Disclosed embodiments of the present invention provide means to obtain correct gas density and flux measurements using (i) gas analyzer (open-path, or closed-path gas analyzers with short intake tube, for example 1 m long, or any combination of the two); (ii) fast temperature or sensible heat flux measurement device (such as, fine-wire thermocouple, sonic anemometer, or any other device providing fast accurate gas temperature measurements); (iii) fast air water content or latent heat flux measurement device (such as, hygrometer, NDIR analyzer, any other device providing fast accurate gas water content measurements); (iv) vertical wind or sampling device (such as sonic anemometer, scintillometer, or fast solenoid valve, etc.) and (v) algorithms in accordance with the present invention to compute the corrected gas flux, compensated for T-P effects.
    Type: Application
    Filed: April 12, 2011
    Publication date: November 3, 2011
    Applicant: LI-COR, Inc.
    Inventors: George Burba, Dayle McDermitt, Anatoly Komissarov, Tyler G. Anderson, Liukang Xu, Bradley A. Riensche
  • Patent number: 7953558
    Abstract: Disclosed embodiments of the present invention provide means to obtain correct gas density and flux measurements using (i) gas analyzer (open-path, or closed-path gas analyzers with short intake tube, for example 1 m long, or any combination of the two); (ii) fast temperature or sensible heat flux measurement device (such as, fine-wire thermocouple, sonic anemometer, or any other device providing fast accurate gas temperature measurements); (iii) fast air water content or latent heat flux measurement device (such as, hygrometer, NDIR analyzer, any other device providing fast accurate gas water content measurements); (iv) vertical wind or sampling device (such as sonic anemometer, scintillometer, or fast solenoid valve, etc.) and (v) algorithms in accordance with the present invention to compute the corrected gas flux, compensated for T-P effects.
    Type: Grant
    Filed: September 3, 2009
    Date of Patent: May 31, 2011
    Assignee: Li-Cor, Inc.
    Inventors: George Burba, Dayle McDermitt, Anatoly Komissarov, Tyler G. Anderson, Liukang Xu, Bradley A. Riensche
  • Publication number: 20110061442
    Abstract: A method and apparatus are provided for maintaining pressure inside a closed chamber equal to the changing outside pressure, detecting leaks in the plumbing (i.e., air handling system) of a trace gas flux measurement system, and estimating the kinetic volume, e.g., of such a system.
    Type: Application
    Filed: November 19, 2010
    Publication date: March 17, 2011
    Applicant: LI-COR, Inc.
    Inventors: Michael D. Furtaw, Dayle K. McDermitt, Liukang Xu
  • Publication number: 20110054803
    Abstract: Disclosed embodiments of the present invention provide means to obtain correct gas density and flux measurements using (i) gas analyzer (open-path, or closed-path gas analyzers with short intake tube, for example 1 m long, or any combination of the two); (ii) fast temperature or sensible heat flux measurement device (such as, fine-wire thermocouple, sonic anemometer, or any other device providing fast accurate gas temperature measurements); (iii) fast air water content or latent heat flux measurement device (such as, hygrometer, NDIR analyzer, any other device providing fast accurate gas water content measurements); (iv) vertical wind or sampling device (such as sonic anemometer, scintillometer, or fast solenoid valve, etc.) and (v) algorithms in accordance with the present invention to compute the corrected gas flux, compensated for T-P effects.
    Type: Application
    Filed: September 3, 2009
    Publication date: March 3, 2011
    Applicant: LI-COR, Inc.
    Inventors: George Burba, Dayle McDermitt, Anatoly Komissarov, Tyler G. Anderson, Liukang Xu, Bradley A. Riensche
  • Patent number: 7856899
    Abstract: A method and apparatus are provided for maintaining pressure inside a closed chamber equal to the changing outside pressure, detecting leaks in the plumbing (i.e., air handling system) of a trace gas flux measurement system, and estimating the kinetic volume, e.g., of such a system.
    Type: Grant
    Filed: February 13, 2009
    Date of Patent: December 28, 2010
    Assignee: LI-COR, Inc.
    Inventors: Michael D. Furtaw, Dayle K. McDermitt, Liukang Xu
  • Patent number: 7748253
    Abstract: A method and apparatus are provided for maintaining pressure inside a closed chamber equal to the changing outside pressure, detecting leaks in the plumbing (i.e., air handling system) of a trace gas flux measurement system, and estimating the kinetic volume, e.g., of such a system.
    Type: Grant
    Filed: February 22, 2005
    Date of Patent: July 6, 2010
    Assignee: LI-COR, Inc.
    Inventors: Michael D. Furtaw, Liukang Xu
  • Publication number: 20090139307
    Abstract: A method and apparatus are provided for maintaining pressure inside a closed chamber equal to the changing outside pressure, detecting leaks in the plumbing (i.e., air handling system) of a trace gas flux measurement system, and estimating the kinetic volume, e.g., of such a system.
    Type: Application
    Filed: February 13, 2009
    Publication date: June 4, 2009
    Applicant: LI-COR, Inc.
    Inventors: Michael D. Furtaw, Dayle K. McDermitt, Liukang Xu
  • Publication number: 20060117840
    Abstract: A method and apparatus are provided for maintaining pressure inside a closed chamber equal to the changing outside pressure, detecting leaks in the plumbing (i.e., air handling system) of a trace gas flux measurement system, and estimating the kinetic volume, e.g., of such a system.
    Type: Application
    Filed: February 22, 2005
    Publication date: June 8, 2006
    Inventors: Michael Furtaw, Dayle McDermitt, Liukang Xu