Timothy H Chen

US Patent:

6339034, Jan 15, 2002

Filed:

Jan 24, 2000

Appl. No.:

09/490677

Inventors:

Ming-Ta S. Hsu - San Jose CA
Timothy S. Chen - San Jose CA

Assignee:

HC Chem Research Service Corp. - San Jose CA

International Classification:

C04B 3514

US Classification:

501 80, 501 85, 501133, 423338

Abstract:

Ultra-high temperature, light-weight, ceramic insulation such as ceramic tile is obtained by pyrolyzing a siloxane gel derived from the reaction of at least one organo dialkoxy silane and at least one tetralkoxy silane in an acid or base liquid medium. The reaction mixture of the tetra- and dialkoxy silanes may contain also an effective amount of a mono- or trialkoxy silane to obtain the siloxane gel. The siloxane gel is dried at ambient pressures to form a siloxane ceramic precursor without significant shrinkage. The siloxane ceramic precursor is subsequently pyrolyzed, in an inert atmosphere, to form the black ceramic insulation comprising atoms of silicon, carbon and oxygen. The ceramic insulation, can be characterized as a porous, uniform ceramic tile resistant to oxidation at temperatures ranging as high as 1700Â C. and is particularly useful as lightweight tiles for spacecraft and other high-temperature insulation applications.

US Patent:

6472067, Oct 29, 2002

Filed:

Sep 27, 2001

Appl. No.:

09/963384

Inventors:

Ming-Ta S. Hsu - San Jose CA
Timothy S. Chen - San Jose CA

Assignee:

HC Chem Research and Service Corp. - San Jose CA

International Classification:

B32B 900

US Classification:

428367, 428408, 428391, 428396, 428447, 428688, 1563071, 1563073, 156311, 156312

Abstract:

Non-flammable, fibrous-siloxane cured composites derived from the polymerization of dialkoxysilanes, trialkoxysilanes and tetraalkoxysilanes, in an aqueous medium, to obtain viscous polysiloxane resins. These siloxane resins are used to impregnate or coat various fibrous materials such as carbon fibers or glass cloth which are subsequently subjected to heat and pressure to form cured, non-flammable siloxane-impregnated composites e. g. panels having a density of about 1 to 3 g/cc. and a limited oxygen index above 30. These non-flammable, fibrous-siloxane composites are particularly useful in the manufacture of fire-proof materials for various transportation vehicles and for building materials e. g. panels as a fire barrier.

US Patent:

6620749, Sep 16, 2003

Filed:

Oct 9, 2001

Appl. No.:

09/972817

Inventors:

Ming-Ta S. Hsu - San Jose CA
Timothy S. Chen - San Jose CA

Assignee:

HC Chem Research and Service Corp. - San Jose CA

International Classification:

C04B 3514

US Classification:

501 80, 501 85, 501133, 423338, 252 62

Abstract:

Ultra-high temperature, light-weight, black ceramic insulation having a density ranging from about 0. 12 g/cc. to 0. 6 g/cc. such as ceramic tile is obtained by pyrolyzing siloxane gels derived from the reaction of at least one organo dialkoxy silane and at least one tetralkoxy silane in an acid or base liquid medium. The reaction mixture of the tetra- and dialkoxy silanes also may contain an effective amount of a mono- or trialkoxy silane to obtain the siloxane gels. The siloxane gels are dried at ambient temperatures and pressures to form siloxane ceramic precursors without significant shrinkage. The siloxane ceramic precursors are subsequently pyrolyzed, in an inert atmosphere, to form the black ceramic insulation comprising atoms of silicon, carbon and oxygen. The ceramic insulation can be characterized as a porous, uniform ceramic tile resistant to oxidation at temperatures ranging as high as 1700Â C. , and particularly useful as lightweight tiles for spacecraft and other high-temperature insulation applications.

US Patent:

7907028, Mar 15, 2011

Filed:

Feb 5, 2009

Appl. No.:

12/366582

Inventors:

Robert Mack - San Jose CA, US
Timothy Chen - Fremont CA, US

Assignee:

Marvell International, Ltd. - Hamilton

International Classification:

H03B 28/00
H03K 5/01
H03L 1/00

US Classification:

331175, 331179, 327100, 327129

Abstract:

A method for compensating NCO jitter by changing a step value used to increment an accumulator in the NCO to make up for inaccuracies, or jitters. In one approach, a remainder in the accumulator may be monitored and a compensated clock close to the current edge of an ideal clock may be generated. In another approach, a compensated clock close to the next edge of the ideal clock may be generated after the current edge of the ideal clock is missed. The step value may be stored in a memory, which may be a register. A jitter compensator may include a comparator for monitoring the remainder in the accumulator or a detector for detecting whether an ideal clock has been missed. The jitter compensator may also change the step value to a step value for a faster clock to compensate jitter.

US Patent:

8289095, Oct 16, 2012

Filed:

Mar 4, 2011

Appl. No.:

13/041145

Inventors:

Robert Mack - San Jose CA, US
Timothy Jay Chen - Fremont CA, US

Assignee:

Marvell International Ltd. - Hamilton

International Classification:

H03L 1/00

US Classification:

331175, 331179, 327106, 375371

Abstract:

A method for compensating NCO jitter by changing a step value used to increment an accumulator in the NCO to make up for inaccuracies, or jitters. In one approach, a remainder in the accumulator may be monitored and a compensated clock close to the current edge of an ideal clock may be generated. In another approach, a compensated clock close to the next edge of the ideal clock may be generated after the current edge of the ideal clock is missed. The step value may be stored in a memory, which may be a register. A jitter compensator may include a comparator for monitoring the remainder in the accumulator or a detector for detecting whether an ideal clock has been missed. The jitter compensator may also change the step value to a step value for a faster clock to compensate jitter.

US Patent:

45673012, Jan 28, 1986

Filed:

Jun 5, 1985

Appl. No.:

6/741405

Inventors:

Robert W. Rosser - San Jose CA
Timothy S. Chen - San Jose CA

Assignee:

The United States of America as represented by the Administrator,
National Aeronautics and Space Administration - Washington DC

International Classification:

C07C12300

US Classification:

564243

Abstract:

Perfluoroether triazine elastomers having improved properties are prepared from oligomeric imidoylamidines that have, in turn, been prepared by the process of (a) reacting a perfluorodinitrile with liquid ammonia to yield a perfluorodiamidine, (b) isolating the perfluorodiamidine, (c) reacting the isolated diamidine with a perfluorodinitrile to yield a perfluoro(imidoylamidine) dinitrile, and then repeating steps (a), (b), and (c) to sequentially grow an oligomer of desired molecular size. The isolated amidine and nitrile intermediates are also disclosed. The elastomers can be fashioned into seals, gaskets, sealing components and the like.

US Patent:

46769625, Jun 30, 1987

Filed:

Aug 28, 1986

Appl. No.:

6/901496

Inventors:

Salvatore R. Riccitiello - San Jose CA
Ming-Ta S. Hsu - San Jose CA
Timothy S. Chen - San Jose CA

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

C01B 3514

US Classification:

423284

Abstract:

The present invention relates to a method of preparing B-trichloroborazine, B. sub. 3 N. sub. 3 Cl. sub. 3 H. sub. 3. Generally, the method includes the combination of gaseous boron trichloride in an anhydrous aprotic organic solvent followed by addition of excess gaseous ammonia at ambient temperature or below. The reaction mixture is heated to between about 100. degree. to 140. degree. C. followed by cooling, removal of the solid ammonium chloride at ambient temperature, distillation of the solvent under vacuum if necessary at a temperature of up to about 112. degree. C. , and recovery of the B-trichloroborazine. Solvents include, toluene, benzene, xylene, chlorinated hydrocarbons, chlorinated aromatic compounds, or mixtures thereof. Toluene is a preferred solvent. The process provides a convenient synthesis of a material which often decomposes on standing.

US Patent:

44341067, Feb 28, 1984

Filed:

Apr 6, 1982

Appl. No.:

6/366025

Inventors:

Robert W. Rosser - San Jose CA
Timothy S. Chen - San Jose CA

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

C07C12300
C07C12000
C07C12143

US Classification:

2604655R

Abstract:

Perfluoroether triazine elastomers having improved properties and utility in seals, gaskets, sealing components and the like are prepared from oligomeric imidoylamidines that have, in turn, been prepared by the process of (a) reacting a perfluorodinitrile with liquid ammonia to yield a perfluorodiamidine, (b) isolating the perfluorodiamidine, (c) reacting the isolated diamidine with a perfluorodinitrile to yield a perfluoro(imidoylamidine) dinitrile, and then repeating steps (a), (b), and (c) to sequentially grow an oligomer of desired molecular size. The isolated amidine and nitrile intermediates are also disclosed.