ETHAN D HOAG
Broker in Boston, MA

5693201, Dec 2, 1997

Oct 19, 1994

8/325486

Michael S. Hsu - Lincoln MA
Ethan D. Hoag - East Boston MA

Ztek Corporation - Waltham MA

C25B 500, C25B 900, C25B 1508, H01M 814

204241

A turbine power system that includes a compressor for compressing a first medium, and an electrochemical converter in communication with the compressor and adapted to receive the first medium and a second medium. The converter is configured to allow an electrochemical reaction between the first and second mediums, thereby generating electricity and producing exhaust having a selected elevated temperature. The power system further includes a turbine in fluid communication with the electrochemical converter and adapted to receive the converter exhaust, such that the turbine converts the electrochemical converter exhaust into rotary energy and electricity. The system can further include a steam generator and a steam turbine that produces electricity. The electrochemical converter is utilized herein as an electrochemical combustor-replacement (ECCR) or as a fuel cell for combustor-replacement (FCCR).

4757514, Jul 12, 1988

Aug 13, 1985

6/765229

Ethan D. Hoag - Boston MA

Laser Corporation of America - Lowell MA

H01S 308

372106

Light generated in the optical resonator of a gas laser is polarized by disposing an array of fine, parallel, highly light reflective wires in the path of the light beam propagating in the resonator. The wires are cooled by conduction of heat to a heat sink or by causing gas to flow through the array. In one embodiment, the wire array is arranged to be rotated to enable the plane of polarization to be turned to any desired orientation. The difference in absorption by the wire array between two orthogonal components of the flux in the resonator need be only in the order of 1% to cause nearly complete linear polarization of the light emerging from the resonator. The parallel wires, preferably, are spaced so that they are situated at the peaks of the lower order modes in the resonator. In lieu of using fine wires, very fine parallel lines or grooves whose width and spacing are such as to provide a low efficiency diffraction grating may be provided in the surface of an optical element of the resonator.

6183703, Feb 6, 2001

Jan 11, 1999

9/459403

Michael S. Hsu - Lincoln MA
Ethan D. Hoag - East Boston MA

Ztek Corporation - Waltham MA

F28D 2100, B01J 802, B01J 3502

422211

A natural gas reformer comprising a stack of thermally conducting plates interspersed with catalyst plates and provided with internal or external manifolds for reactants. The catalyst plate is in intimate thermal contact with the conducting plates so that its temperature closely tracks the temperature of the thermally conducting plate, which can be designed to attain a near isothermal state in-plane to the plate. One or more catalysts may be used, distributed along the flow direction, in-plane to the thermally conducting plate, in a variety of optional embodiments. The reformer may be operated as a steam reformer or as a partial oxidation reformer. When operated as a steam reformer, thermal energy for the (endothermic) steam reforming reaction is provided externally by radiation and/or conduction to the thermally conducting plates. This produces carbon monoxide, hydrogen, steam and carbon dioxide. When operated as a partial oxidation reformer, a fraction of the natural gas is oxidized assisted by the presence of a combustion catalyst and reforming catalyst.

5338622, Aug 16, 1994

Apr 12, 1993

8/045996

Michael S. Hsu - Lincoln MA
Ethan D. Hoag - East Boston MA

Ztek Corporation - Waltham MA

H01M 804

429 26

A heat exchanging apparatus including a working fluid and a structure for exchanging heat between the working fluid and an external environment. The structure includes at least one wall element having an external surface exposed to the external environment and an internal surface exposed to the working fluid such that heat can be exchanged between the environment and the working fluid by conductive heat transfer through the wall element. The apparatus further includes a reservoir element for providing a reservoir for the working fluid and a distribution element for distributing the working fluid along the wall element to provide isothermal heat exchange between the working fluid and the external environment. In one embodiment, the structure can be a double lumen tubular structure having an inner lumen which provides a reservoir for the working fluid, and an lumen where heat is exchanged between the working fluid and an external environment. The inner tube can be a porous structure with a plurality of pores that uniformly distribute the working fluid to the outer-lumen.

4686680, Aug 11, 1987

Jun 25, 1985

6/748505

Ethan Hoag - East Boston MA
Glenn Zeiders - Marblehead MA

Laser Corporation of America - Lowell MA

H01S 322

372 58

A gas laser of the type in which gas is impelled transversely through a region where lasing of the flowing gas occurs, employs a crossfield blower to propel the gas around a closed loop. The crossfield blower has an elongate impeller that is substantially the same length as the lasing region. The impeller generates at least one vortex in the gas flow. A part of that vortex is situated outside the path of the main gas flow to the lasing region. To remove heat from the gas without appreciably interfering with the main gas flow to the lasing region, cooling means are situated in that part of the vortex that is outside the path of the main gas flow to the lasing region.

4726032, Feb 16, 1988

Mar 20, 1986

6/841766

Ethan D. Hoag - Boston MA

Laser Corporation of America - Lowell MA

H01S 310, H01S 308, H01S 304

372106

A comb-shaped polarizing device for use in a laser is compact, inexpensive and easily adjusted. The device includes an annular member having a number of comb-shaped teeth projecting opposite similarly shaped teeth from a rectangular aperture. The comb-shaped teeth are arranged in a plane transversing a laser beam which is under oscillation. Cooling water passages are formed in the annular member. In one embodiment the annular member is provided at its periphery with gear teeth which mate with a motor for selection of the direction of polarization of the laser beam.

4755720, Jul 5, 1988

Mar 20, 1986

6/841760

Ethan D. Hoag - Boston MA

Laser Corporation of America - Lowell MA

H01J 115, H01J 188, H01J 1706

313619

A pin-shaped discharge electrode is provided which prevents corrosion and promotes stable glow discharge. In order to reduce the occurrence of a large field near the bottom of the electrode, the electrode is embedded in a cavity of an insulating base plate.

3982200, Sep 21, 1976

Sep 4, 1973

5/394350

Ethan D. Hoag - Boston MA
Henry E. Pease - Malden MA

Avco Everett Research Laboratory, Inc. - Everett MA

H01s 322

331 945P

A two chamber electrically pumped electron beam stabilized gas discharge laser is enabled to operate at lower electron accelerating voltages for given power applications through provision of very thin separating diaphragms. The apparatus is controlled throughout initial pump down, laser gas filling, laser operation and air release phases to prevent occurrence of a diaphragm rupturing pressure differential between the two chambers or the inadvertent malsequencing of chamber evacuation and backfill.

4698551, Oct 6, 1987

Mar 20, 1986

6/841767

Ethan D. Hoag - Boston MA

Laser Corporation of America - Lowell MA

H01J 1704, H01S 309

313619

A discharge electrode for a gas discharge device has pin-shaped electrodes which are effectively cooled in the gas flow and which promote a stable glow-discharge. The pin-shaped electrodes are made from a wire member which is curled at its end. An extension portion of the electrodes extends a predetermined length from the curled end, and is bent in an approximately L-shape to form a post position. The pin-shaped electrode is disposed in the gas flow so that the extension portion is orthogonal to the gas flow.

4486887, Dec 4, 1984

Aug 23, 1982

6/410594

Ethan D. Hoag - East Boston MA
Glenn W. Zieders - Marble-Head MA

Metalworking Lasers International Ltd. - Neve Sharet

H01S 322

372 58

A high-power flowing-gas laser comprises a laser channel folded to include at least two legs angularly disposed to each other in a common plane and having a single folding mirror between them such that the laser rays through one leg, on the upstream side thereof with respect to the gas flowing transversely across that leg, are reflected by the folding mirror so as to be transposed to the downstream side of the other leg with respect to the gas flowing transversely across the other leg. A number of embodiments are described wherein the laser channel is folded to include four or other even number of legs according to a polygonal configuration, there being a separate flowing gas channel for each leg, all the gas channels directing the gas flow radially inwardly to a common collection region. Among the advantages provided by the described constructions are compensation for phase distortion and amplitude variations, and maximum laser channel length and laser output for a given system size and volume.