David A Arthur

US Patent:

6762237, Jul 13, 2004

Filed:

Jun 10, 2002

Appl. No.:

10/165306

Inventors:

Paul J. Glatkowski - Littleton MA
David J. Arthur - Norwood MA

Assignee:

Eikos, Inc. - Franklin MA

International Classification:

C08K 304

US Classification:

524496, 524495

Abstract:

The present invention relates to a novel nanocomposite dielectric comprising a polymer matrix and a plurality of carbon nanotubes dispersed therein. A method for increasing a dielectric constant of a polymer matrix, as well as a laminate and mobile antenna comprising the novel dielectric are also disclosed.

US Patent:

6988925, Jan 24, 2006

Filed:

May 21, 2003

Appl. No.:

10/442176

Inventors:

David J. Arthur - Norwood MA, US
Paul J. Glatkowski - Littleton MA, US

Assignee:

Eikos, Inc. - Franklin MA

International Classification:

H01J 9/04
H01J 9/12
H01J 9/14

US Classification:

445 46, 427 77, 427197

Abstract:

A method for making a nanocomposite electrode or circuit pattern includes forming a continuous carbon nanotube layer impregnated with a binder and patterning the binder resin using various printing or photo imaging techniques. An alternative method includes patterning the carbon nanotube layer using various printing or imaging techniques and subsequently applying a continuous coating of binder resin to the patterned carbon nanotube layer. Articles made from these patterned nanocomposite coatings include transparent electrodes and circuits for flat panel displays, photovoltaics, touch screens, electroluminescent lamps, and EMI shielding.

US Patent:

7378040, May 27, 2008

Filed:

Aug 11, 2005

Appl. No.:

11/201275

Inventors:

Jiazhong Luo - Acton MA, US
David J. Arthur - Norwood MA, US
Paul J. Glatkowski - Littletown MA, US

Assignee:

Eikos, Inc. - Franklin MA

International Classification:

H01B 1/00

US Classification:

252500, 252502, 252511, 427 77, 156 60, 174546, 4234471, 423445 R

Abstract:

This invention relates to flexible, transparent and conductive coatings and films formed using carbon nanotubes (CNT) and, in particular, single wall CNT, with polymer binders. Preferably, coatings and films are formed from CNT applied to transparent substrates forming one or multiple conductive layers at nanometer level of thickness. Polymer binders are applied to the CNT network coating having an open structure to provide protection through infiltration, and may comprise a basecoat, a topcoat, or a combination thereof, providing enhanced optical transparency, conductivity, moisture resistance, thermal resistance, abrasion resistance and interfacial adhesion. Polymers may be thermoplastics, thermosets, insulative, conductive or a combination thereof. A fluoropolymer containing binder is applied onto a CNT-based transparent conductive coating at nanometer level of thickness on a clear substrate. The fluoropolymers or blend can be either semi-crystalline or amorphous.

US Patent:

7517600, Apr 14, 2009

Filed:

Jun 1, 2006

Appl. No.:

11/445362

Inventors:

David A. Arthur - Honeoye Falls NY, US
Manish Sinha - Pittsford NY, US

Assignee:

GM Global Technology Operations, Inc. - Detroit MI

International Classification:

H01M 8/04

US Classification:

429 23, 429 26, 429 25

Abstract:

A control system for a fuel cell stack that controls the relative humidity of the cathode outlet gas during stack power transients to provide better cathode outlet gas relative humidity control by reducing the dynamic pressure range and thus the dynamic cathode outlet gas relative humidity range. In one embodiment, the control system uses a first narrower cathode pressure range based on stack current density during stack power transients to provide better cathode outlet gas relative humidity control, and uses a second wider cathode pressure range based on stack current density during low current density and steady-state current density to improve system efficiency by decreasing compressor parasitics.

US Patent:

7608351, Oct 27, 2009

Filed:

Oct 7, 2005

Appl. No.:

11/245755

Inventors:

Manish Sinha - Pittsford NY, US
David A. Arthur - Honeoye Falls NY, US
Matthew K. Hortop - Rochester NY, US

Assignee:

GM Global Technology Operations, Inc. - Detroit MI

International Classification:

H01M 8/04

US Classification:

429 13, 429 23, 429 34

Abstract:

A system and method for providing dynamic cathode stoichiometry control in a fuel cell during stack load transients to minimize relative humidity excursions. Particularly, changes in the cathode stoichiometry is controlled as a function of time in response to a decrease or increase in stack current density. Thus, if the stack current density drops to a predetermined current density, the dynamic stoichiometry logic will monitor the low power condition and determine if the condition is sustained, i. e. , for an extended period of time. If the low power condition is not sustained, then the cathode stoichiometry does not change, but if it is sustained, then the cathode stoichiometry is increased. The same delay in changing the cathode stoichiometry can be provided for a transition from a low power condition to a high power condition.

US Patent:

7641993, Jan 5, 2010

Filed:

Jun 9, 2006

Appl. No.:

11/449931

Inventors:

David A. Arthur - Honeoye Falls NY, US
Abdullah B. Alp - West Henrietta NY, US

Assignee:

GM Global Technology Operations, Inc. - Detroit MI

International Classification:

H01M 8/04

US Classification:

429 13, 429 25

Abstract:

A system and method for limiting the amount of hydrogen being bled from an anode exhaust line. The method includes maintaining a pressure bias between an anode outlet and a cathode outlet of a fuel cell stack so that when an anode exhaust gas is bled from the anode exhaust line and mixed with the cathode exhaust gas, the concentration of hydrogen in the mixed gas is maintained below a predetermined percentage. The pressure bias is such that the anode exhaust gas has a higher gas pressure than the cathode exhaust gas.

US Patent:

7695839, Apr 13, 2010

Filed:

Oct 16, 2006

Appl. No.:

11/549766

Inventors:

David A. Arthur - Honeoye Falls NY, US
Abdullah B. Alp - West Henrietta NY, US

Assignee:

GM Global Technology Operations, Inc. - Detroit MI

International Classification:

H01M 8/04
H01M 8/12
H01M 8/00

US Classification:

429 25, 429 13

Abstract:

A fuel cell system that employs a method for increasing stack power ramp up for high power up-transients by decoupling the build-up of stack current density from the cathode side pressure. The system gives the compressor power priority during the power up-transient to quickly provide the proper compressor speed, and therefore the proper air mass flow, for the desired current density of the fuel cell stack. The system also maintains the cathode side pressure of the stack low by keeping a cathode back-pressure valve open. By increasing the cathode input airflow rate to the proper level at the power up-transient, the current density of the stack will increase to the desired stack power level. Subsequently, the back-pressure valve is closed to increase the stack voltage to provide the total maximum power achievable by the stack.

US Patent:

7718291, May 18, 2010

Filed:

Feb 1, 2007

Appl. No.:

11/669965

Inventors:

David A. Arthur - Honeoye Falls NY, US
Abdullah B. Alp - West Henrietta NY, US

Assignee:

GM Global Technology Operations, Inc. - Detroit MI

International Classification:

H01M 8/04

US Classification:

429 26

Abstract:

A method of controlling the relative humidity in an electrochemical conversion device comprises the steps of: providing a fuel cell stack comprising a plurality of fuel cells stackingly arranged, and at least one heater coupled to at least one end fuel cell; selecting a relative humidity setpoint for the at least one end cell; calculating an end cell membrane electrode assembly temperature setpoint using the relative humidity setpoint; calculating a heater temperature setpoint equal to the calculated end cell membrane electrode assembly temperature setpoint plus a computed temperature difference from the at least one end cell membrane electrode assembly to the heater; and adjusting the temperature of the end cell heater until it reaches the heater temperature setpoint and thereby achieves the relative humidity setpoint of the at least end cell membrane electrode assembly.