David J Duff

US Patent:

20100143581, Jun 10, 2010

Filed:

Dec 9, 2008

Appl. No.:

12/331355

Inventors:

Craig Eldershaw - Belmont CA, US
David G. Duff - Portola Valley CA, US

Assignee:

Palo Alto Research Center Incorporated - Palo Alto CA

International Classification:

B05D 5/12
B67D 5/56

US Classification:

427 75, 222129

Abstract:

A solar cell extrusion printing system includes a printhead assembly having one or more elongated valve structures that are adjustably disposed adjacent to the outlet orifices of selected nozzle channels, and a valve control device for controlling the position of the valve structures to facilitate controllable ink flow through selected nozzle channels of the printhead assembly during the gridline printing process. The printhead assembly defines an elongated opening (e.g., a slot or hole) that that intersects (i.e., passes through) each of the selected nozzle channels, and an elongated member is movably disposed in the slot and is selectively movable between a first (opened) position, in which the valve structure extrusion material is passed by the valve structure through the nozzle channel and out of the printhead, and a closed position, in which the extrusion material is blocked by the valve structure and prevented from passing through the nozzle channel.

US Patent:

20120158196, Jun 21, 2012

Filed:

Dec 21, 2010

Appl. No.:

12/973999

Inventors:

Craig Eldershaw - Belmont CA, US
David G. Duff - Portola Valley CA, US

Assignee:

PALO ALTO RESEARCH CENTER INCORPORATED - Palo Alto CA

International Classification:

G06F 1/28
H02J 3/38

US Classification:

700287, 307 18

Abstract:

A tactical smart grid system and method includes a plurality of energy generators and a plurality of loads, where the loads require energy from at least some of the energy generators. A plurality of interface units are provided, where each energy generator and load are connected to one of the plurality of interface units. Each of the interface units including a controller to thereby provide distributed intelligence and distributed system control, thereby removing the requirement of a centrally controlled system.

US Patent:

57059284, Jan 6, 1998

Filed:

Jun 14, 1996

Appl. No.:

8/665165

Inventors:

Ronald L. Haner - San Francisco CA
Christopher C. Kellogg - Walnut Creek CA
David W. Duff - Ipswich MA

Assignee:

Varian Associates, Inc. - Palo Alto CA

International Classification:

G01V 300

US Classification:

324321

Abstract:

A sample delivery system for a flow-through NMR analysis is provided, which utilizes pressurized gas as a means for conveying a sample into and out of an NMR spectrometer. Two sources of gas pressure, a forward pressure and back pressure, oppose the sample within the tubing of the sample delivery system and the tubing of the flow-through system which are operatively coupled together. Conveyance of the sample in any direction within the tubing is achieved by adjusting the pressure differential. Precise positioning of the sample in the magnetic field center and complete removal of the sample from the NMR spectrometer when analysis is complete are achieved by using a signal processor which receives signals from the NMR detector or other detectors positioned along the length of the tubing. These signals provide an indication of the position of the sample in the tubing. The signal processor uses this information to adjust the forward and back pressure, thereby achieving the desired positioning of the sample.