Patents by Inventor David Scott Nelson

David Scott Nelson 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: 9290823
    Abstract: Described herein are a method, an apparatus, and a system for metal processing that improves one or more properties of a sintered metal part by controlling the process conditions of the cooling zone of a continuous furnace using one or more cryogenic fluids. In one aspect, there is provided a method comprising: providing a furnace wherein the metal part is passed therethough on a conveyor belt and comprises a hot zone and a cooling zone wherein the cooling zone has a first temperature; and introducing a cryogenic fluid into the cooling zone where the cryogenic fluid reduces the temperature of the cooling zone to a second temperature, wherein at least a portion of the cryogenic fluid provides a vapor within the cooling zone and cools the metal parts passing therethrough at an accelerated cooling rate.
    Type: Grant
    Filed: February 17, 2011
    Date of Patent: March 22, 2016
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Zbigniew Zurecki, Ranajit Ghosh, Lisa Ann Mercando, Xiaoyi He, John Lewis Green, David Scott Nelson
  • Publication number: 20120055592
    Abstract: Described herein are a method, an apparatus, and a system for metal processing that improves one or more properties of a sintered metal part by controlling the process conditions of the cooling zone of a continuous furnace using one or more cryogenic fluids. In one aspect, there is provided a method comprising: providing a furnace wherein the metal part is passed therethough on a conveyor belt and comprises a hot zone and a cooling zone wherein the cooling zone has a first temperature; and introducing a cryogenic fluid into the cooling zone where the cryogenic fluid reduces the temperature of the cooling zone to a second temperature, wherein at least a portion of the cryogenic fluid provides a vapor within the cooling zone and cools the metal parts passing therethrough at an accelerated cooling rate.
    Type: Application
    Filed: February 17, 2011
    Publication date: March 8, 2012
    Applicant: AIR PRODUCTS AND CHEMICALS, INC.
    Inventors: Zbigniew Zurecki, Ranajit Ghosh, Lisa Ann Mercando, Xiaoyi He, John Lewis Green, David Scott Nelson
  • Patent number: 7702034
    Abstract: A circuit 30 for upsampling and upconverting a high rate signal that is divided into M in-phase (I) symbols and M quadrature (Q) symbols. A Nyquist filter 32 upsamples by a factor of k each of the 2M symbols in parallel during one system clock period (CP). The filter 32 has a plurality of 2kM filter components 40, 42, that each provides a continuous output. A plurality of multipliers 50, 52 each upconverts a filter component output with a carrier wave signal 46, 48 that is output from a numerically controlled oscillator 44. A plurality of adders 54 each adds the output of two multipliers 50 to recombine corresponding I and Q samples to output kM samples during a CP. For continuous phase modulation, N parallel bits are input into the filter 32, upsampled in one CP, and accumulated and modulated 82 in parallel in one CP. For analog processing, M (I) and M (Q) symbols are input into an FIR filter 77a, 77b for upsampling, and decimated at a MUX/DAC block 78 for subsequent analog upconversion.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: April 20, 2010
    Assignee: L3 Communications Corporation
    Inventors: Osama Sami Haddadin, L. Andrew Gibson, Jr., David Scott Nelson
  • Patent number: 7515651
    Abstract: A circuit 30 for upsampling and upconverting a high rate signal that is divided into M in phase (I) symbols and M quadrature (Q) symbols. A Nyquist filter 32 upsamples by a factor of k each of the 2M symbols in parallel during one system clock period (CP). The filter 32 has a plurality of 2kM filter components 40, 42, that each provides a continuous output. A plurality of multipliers 50, 52 each upconverts a filter component output with a carrier wave signal 46, 48 that is output from a numerically controlled oscillator 44. A plurality of adders 54 each adds the output of two multipliers 50 to recombine corresponding I and Q samples to output kM samples during a CP. For continuous phase modulation, N parallel bits are input into the filter 32, upsampled in one CP, and accumulated and modulated 82 in parallel in one CP. For analog processing, M (I) and M (Q) symbols are input into an FIR filter 77a, 77b for upsampling, and decimated at a MUX/DAC block 78 for subsequent analog upconversion.
    Type: Grant
    Filed: August 7, 2003
    Date of Patent: April 7, 2009
    Assignee: L3 Communications Corporation
    Inventors: Osama Sami Haddadin, L. Andrew Gibson, Jr., David Scott Nelson
  • Patent number: 7340024
    Abstract: A circuit for single or parallel digital fractional interpolation of data samples has a fractional interpolator filter, an oscillator for outputting timing signals to the fractional interpolator filter, and a detector loop with a strobe feedback from the oscillator for outputting a frequency adjustment to the oscillator. Three different approaches are shown to determine the frequency adjustment. One approach is to generate a pulse based on the symbol clock, and measure the differences between the pulse and the strobe and between the strobe and the pulse. The smaller is the frequency adjustment. Another approach is to adjust the strobe period to match the symbol clock period. A third approach is to add an oscillator-driven clock to the symbol clock and integrate the sum over a symbol clock period to generate the frequency adjustment.
    Type: Grant
    Filed: October 22, 2003
    Date of Patent: March 4, 2008
    Assignee: L3 Communications Corporation
    Inventors: David Scott Nelson, L. Andrew Gibson, Jr., Osama Sami Haddadin, Michael Dennis Pulsipher