Patents by Inventor David J. Walker
David J. Walker 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).
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Publication number: 20120151234Abstract: A method for implementing a sleep control that includes the steps of receiving a message from a sending block via a messaging bus, wherein the message is destined for a receiving block; determining whether the receiving block is awake; and delaying further transmission of the message until the receiving block is awake. An apparatus for performing the method is also disclosed.Type: ApplicationFiled: December 16, 2010Publication date: June 14, 2012Applicant: QUALCOMM IncorporatedInventors: Edward H. Teague, David J. Walker
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Patent number: 8047162Abstract: A system and method for quickly cooling and de-pressurizing a boiler arrangement in the event of a plant power loss, a.k.a. a black plant condition. A steam discharge system injects steam from the steam/water circuit into the furnace, thereby both cooling components of the boiler arrangement and reducing pressure in the steam/water circuit. This reduces or eliminates the additional cost associated with providing extra capacity in a steam drum and/or an independently powered boiler water pump. The system and method is particularly useful for quickly cooling the U-beams of a circulating fluidized bed (CFB) boiler during a black plant condition. In application to boiler arrangements with a selective non-catalytic reduction (SNCR) system employing steam as a carrier for a NOx reducing agent, the steam discharge system advantageously uses the discharge nozzles of the SNCR system to inject the steam into the furnace.Type: GrantFiled: July 17, 2008Date of Patent: November 1, 2011Assignee: Babcock & Wilcox Power Generation Group, Inc.Inventors: Mikhail Maryamchik, Michael J. Szmania, David J. Walker, Donald L. Wietzke
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Patent number: 7656170Abstract: Disclosed is a method of inspecting a sample. The sample is scanned in a first direction with at least one particle beam. The sample is scanned in a second direction with at least one particle beam. The second direction is at an angle to the first direction. The number of defects per an area of the sample are found as a result of the first scan, and the position of one or more of the found defects is determined from the second scan. In a specific embodiment, the sample includes a test structure having a plurality of test elements thereon. A first portion of the test elements is exposed to the beam during the first scan to identify test elements having defects, and a second portion of the test elements is exposed during the second scan to isolate and characterize the defect.Type: GrantFiled: February 14, 2007Date of Patent: February 2, 2010Assignee: KLA-Tencor Technologies CorporationInventors: Gustavo A. Pinto, Brian C. Leslie, David L. Adler, Akella V. S. Satya, Padma A. Satya, legal representative, Robert Thomas Long, David J. Walker
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Patent number: 7543647Abstract: An improved well completion system for completing two or more separate production zones in a well bore during a single downhole trip is disclosed. The improved completion system comprises a completion assembly comprising two or more production zone assemblies and a completion tool assembly. Each production zone assembly may comprise an automatic system locating assembly and at least two inverted seal systems for sealing against the tool assembly.Type: GrantFiled: December 22, 2006Date of Patent: June 9, 2009Assignee: BJ Services CompanyInventor: David J. Walker
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Patent number: 7490669Abstract: An improved well completion system for completing two or more separate production zones in a well bore during a single downhole trip is disclosed. The improved completion system comprises a completion assembly comprising two or more production zone assemblies and a completion tool assembly. Each production zone assembly may comprise an automatic system locating assembly and at least two inverted seal systems for sealing against the tool assembly.Type: GrantFiled: May 5, 2006Date of Patent: February 17, 2009Assignee: BJ Services CompanyInventors: David J. Walker, Dewayne M. Turner, Gregg W. Stout, Todd Chretien, Christopher L. Blackler, Jack Robbins, Marvin B. Traweek
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Publication number: 20090025658Abstract: A system and method for quickly cooling and de-pressurizing a boiler arrangement in the event of a plant power loss, a.k.a. a black plant condition. A steam discharge system injects steam from the steam/water circuit into the furnace, thereby both cooling components of the boiler arrangement and reducing pressure in the steam/water circuit. This reduces or eliminates the additional cost associated with providing extra capacity in a steam drum and/or an independently powered boiler water pump. The system and method is particularly useful for quickly cooling the U-beams of a circulating fluidized bed (CFB) boiler during a black plant condition. In application to boiler arrangements with a selective non-catalytic reduction (SNCR) system employing steam as a carrier for a NOx reducing agent, the steam discharge system advantageously uses the discharge nozzles of the SNCR system to inject the steam into the furnace.Type: ApplicationFiled: July 17, 2008Publication date: January 29, 2009Inventors: Mikhail Maryamchik, Michael J. Szmania, David J. Walker, Donald L. Wietzke
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Publication number: 20090021010Abstract: A closed-cycle system and method of electrical power generation uses steam to transport charge carriers through an MHD generator. Water droplets, fine particles or mixtures thereof are used as the charge carriers. The fine particles are sufficiently small to allow the particles to pass through pumps and other equipment in the flow path with little or no damage, thereby eliminating the need to remove and re-inject a seed material, or treat it prior to discharge to the environment. The high operating temperatures of prior art MHD generators are avoided, thereby allowing more economical and readily available materials to be used. The system and method also allows the MHD generator to be used as the bottoming cycle in a single-loop power generation system, with a conventional steam turbine-generator used as the topping cycle, resulting in an increased heat rate with reduced emissions of greenhouse gases and other pollutants, and with reduced heat rejection to the environment per unit of electricity produced.Type: ApplicationFiled: July 19, 2007Publication date: January 22, 2009Inventor: David J. Walker
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Patent number: 7464669Abstract: An integrated fluidized bed ash cooler for a fluidized bed boiler, particularly a circulating fluidized bed (CFB) boiler, employs at least two fluidized bed sections positioned in series along a solids flow path. Each section contains fluidizing means, the first section along the solids path being separated from a following section with a threshold. The first section contains means for measuring a bed temperature in the vicinity of the fluidizing means and at a higher elevation within the fluidized bed. Means are provided for removing oversized bed material from the first section to facilitate the removal of ash while minimizing the possibility of ash plugging during operation.Type: GrantFiled: April 19, 2006Date of Patent: December 16, 2008Inventors: Mikhail Maryamchik, Michael J. Szmania, David E. James, David J. Walker, Donald L. Wietzke
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Publication number: 20080246030Abstract: Disclosed is a semiconductor die having a scanning area. The semiconductor die includes a first plurality of test structures wherein each of the test structures in the first plurality of test structures is located entirely within the scanning area. The semiconductor die further includes a second plurality of test structures wherein each of the test structures in the first plurality of test structures is located only partially within the scanning area. The test structures are arranged so that a scan of the scanning area results in detection of defects outside of the scanning area.Type: ApplicationFiled: February 14, 2007Publication date: October 9, 2008Inventors: Akella V.S. Satya, Gustavo A. Pinto, David L. Adler, Robert Thomas Long, Neil Richardson, Kurt H. Weiner, David J. Walker, Lynda C. Mantalas, Padma A. Satya
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Publication number: 20080237487Abstract: Disclosed is a method of inspecting a sample. The sample is scanned in a first direction with at least one particle beam. The sample is scanned in a second direction with at least one particle beam. The second direction is at an angle to the first direction. The number of defects per an area of the sample are found as a result of the first scan, and the position of one or more of the found defects is determined from the second scan. In a specific embodiment, the sample includes a test structure having a plurality of test elements thereon. A first portion of the test elements is exposed to the beam during the first scan to identify test elements having defects, and a second portion of the test elements is exposed during the second scan to isolate and characterize the defect.Type: ApplicationFiled: February 14, 2007Publication date: October 2, 2008Inventors: Gustavo A. Pinto, Brian C. Leslie, David L. Adler, Akella V.S. Satya, Robert Thomas Long, David J. Walker, Padma A. Satya
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Patent number: 7282087Abstract: An inert impingement surface that is pliable and which, when set in motion, works to shed itself of particle deposits. The pliable surface may be formed of a plurality of coactive members that co-operate with one another to clean-off the particle deposits from each other's surfaces. The coactive members may be in the form of chains, rods, cables, wires, granular inert materials such as gravel or metal balls or other impact means. The pliable surface may also be formed of a heat-resistant material which is caused to experience a continuing shape change, thereby casting-off the particle deposits adhering to the surface.Type: GrantFiled: September 23, 2004Date of Patent: October 16, 2007Assignee: The Babcock & Wilcox CompanyInventors: Mikhail Maryamchik, David J. Walker
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Patent number: 7150326Abstract: The present invention provides a bi-directional ball seat and method of use. In at least one embodiment, the present invention provides a fluid control system that includes a radial protrusion that can be selectively engaged and disengaged upstream and/or from a ball seat. For example, a ball can be placed in a passageway, engaged with a downstream ball seat, and the radial protrusion radially extended into the passageway distally from the seat relative to the ball. A reverse movement of the ball is restricted by the active radial movement of the radial protrusion into the passageway. The control system can be used to control a variety of tools associated with the well. Without limitation, the tools can include crossover tools, sleeves, packers, safety valves, separators, gravel packers, perforating guns, decoupling tools, valves, and other tools know to those with ordinary skills in the art.Type: GrantFiled: March 27, 2006Date of Patent: December 19, 2006Assignee: BJ Services CompanyInventors: Floyd Romaine Bishop, Marvin Bryce Traweek, Richard J. Ross, David J. Walker, Dewayne M. Turner
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Patent number: 7021389Abstract: The present invention provides a bi-directional ball seat and method of use. In at least one embodiment, the present invention provides a fluid control system that includes a radial protrusion that can be selectively engaged and disengaged upstream and/or from a ball seat. For example, a ball can be placed in a passageway, engaged with a downstream ball seat, and the radial protrusion radially extended into the passageway distally from the seat relative to the ball. A reverse movement of the ball is restricted by the active radial movement of the radial protrusion into the passageway. The control system can be used to control a variety of tools associated with the well. Without limitation, the tools can include crossover tools, sleeves, packers, safety valves, separators, gravel packers, perforating guns, decoupling tools, valves, and other tools know to those with ordinary skills in the art.Type: GrantFiled: February 24, 2003Date of Patent: April 4, 2006Assignee: BJ Services CompanyInventors: Floyd Romaine Bishop, Marvin Bryce Traweek, Richard J. Ross, David J. Walker, DeWayne M. Turner
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Patent number: 7012439Abstract: Disclosed is a method of inspecting a sample. The sample is scanned in a first direction with at least one particle beam. The sample is scanned in a second direction with at least one particle beam. The second direction is at an angle to the first direction. The number of defects per an area of the sample are found as a result of the first scan, and the position of one or more of the found defects is determined from the second scan. In a specific embodiment, the sample includes a test structure having a plurality of test elements thereon. A first portion of the test elements is exposed to the beam during the first scan to identify test elements having defects, and a second portion of the test elements is exposed during the second scan to isolate and characterize the defect.Type: GrantFiled: February 15, 2005Date of Patent: March 14, 2006Assignee: KLA-Tencor Technologies CorporationInventors: Gustavo A. Pinto, Brian C. Leslie, David L. Adler, Akella V. S. Satya, Robert Thomas Long, David J. Walker
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Patent number: 6984822Abstract: An apparatus and method for inspecting a surface of a sample, particularly but not limited to a semiconductor device, using an electron beam is presented. The technique is called Secondary Electron Emission Microscopy (SEEM), and has significant advantages over both Scanning Electron Microscopy (SEM) and Low Energy Electron Microscopy (LEEM) techniques. In particular, the SEEM technique utilizes a beam of relatively high-energy primary electrons having a beam width appropriate for parallel, multi-pixel imaging. The electron energy is near a charge-stable condition to achieve faster imaging than was previously attainable with SEM, and charge neutrality unattainable with LEEM. The emitted electrons may be detected using a time delay integration detector.Type: GrantFiled: April 2, 2003Date of Patent: January 10, 2006Assignee: KLA-Tencor CorporationInventors: David L. Adler, David J. Walker, Fred Babian, Travis Wolfe
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Patent number: 6921672Abstract: Disclosed is a semiconductor die having a scanning area. The semiconductor die includes a first plurality of test structures wherein each of the test structures in the first plurality of test structures is located entirely within the scanning area. The semiconductor die further includes a second plurality of test structures wherein each of the test structures in the first plurality of test structures is located only partially within the scanning area. The test structures are arranged so that a scan of the scanning area results in detection of defects outside of the scanning area.Type: GrantFiled: January 7, 2003Date of Patent: July 26, 2005Assignee: KLA-Tencor Technologies CorporationInventors: Akella V. S. Satya, Gustavo A. Pinto, David L. Adler, Robert Thomas Long, Neil Richardson, Kurt H. Weiner, David J. Walker, Lynda C. Mantalas
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Patent number: 6868795Abstract: A bubble cap assembly for use in fluidized bed boilers, furnaces, or reactors, has a bubble cap, a stem, and at least one pin. One end of the stem is inserted into the bubble cap. The bubble cap has outlet holes for delivering a fluidizing medium, typically into a bed of granulated material, but which prevent backsifting of the granulated material into the bubble cap. The bubble cap also has at least one insertion hole, through which a pin may be inserted. When the pin is inserted through the bubble cap insertion hole, it also occupies a groove or indentation on the stem thereby preventing separation or disassembly of the bubble cap and stem combination. An elastic gasket may be provided between the bubble cap and stem to form a fluid tight connection.Type: GrantFiled: May 29, 2003Date of Patent: March 22, 2005Assignees: The Babcock & Wilcox Company, Blasch Precision Ceramics, Inc.Inventors: Mikhail Maryamchik, Gary L. Anderson, Jeffrey J. Hahn, Edwin L. Collins, III, David J. Walker, Jeffrey J. Bolebruch
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Patent number: 6867606Abstract: Disclosed is a method of inspecting a sample. The sample is scanned in a first direction with at least one particle beam. The sample is scanned in a second direction with at least one particle beam. The second direction is at an angle to the first direction. The number of defects per an area of the sample are found as a result of the first scan, and the position of one or more of the found defects is determined from the second scan. In a specific embodiment, the sample includes a test structure having a plurality of test elements thereon. A first portion of the test elements is exposed to the beam during the first scan to identify test elements having defects, and a second portion of the test elements is exposed during the second scan to isolate and characterize the defect.Type: GrantFiled: March 13, 2003Date of Patent: March 15, 2005Assignee: KLA-Tencor Technologies, Inc.Inventors: Gustavo A. Pinto, Brian C. Leslie, David L. Adler, Akella V. S. Satya, Robert Thomas Long, David J. Walker
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Patent number: 6863703Abstract: A circulating fluidized bed (CFB) unit utilizing a mechanical dust collector located in a vertical flue above at least one heat exchange surface, and at least partially underneath the floor of a non-vertical flue, includes a plurality of individual collection elements each having a downward bottom outlet for a flow of cleaned gas conveyed through the collection elements.Type: GrantFiled: April 30, 2002Date of Patent: March 8, 2005Assignee: The Babcock & Wilcox CompanyInventors: Mikhail Maryamchik, Felix Belin, David J. Walker, Donald L. Wietzke
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Publication number: 20040237858Abstract: A bubble cap assembly for use in fluidized bed boilers, furnaces, or reactors, has a bubble cap, a stem, and at least one pin. One end of the stem is inserted into the bubble cap. The bubble cap has outlet holes for delivering a fluidizing medium, typically into a bed of granulated material, but which prevent backsifting of the granulated material into the bubble cap. The bubble cap also has at least one insertion hole, through which a pin may be inserted. When the pin is inserted through the bubble cap insertion hole, it also occupies a groove or indentation on the stem thereby preventing separation or disassembly of the bubble cap and stem combination. An elastic gasket may be provided between the bubble cap and stem to form a fluid tight connection.Type: ApplicationFiled: May 29, 2003Publication date: December 2, 2004Inventors: Mikhail Maryamchik, Gary L. Anderson, Jeffrey J. Hahn, Edwin L. Collins, David J. Walker, Jeffrey J. Bolebruch