Abstract: A high surface area substrate with controlled pore size and slot geometry is made by depositing at least two materials in alternating layers. The film is then broken up and one of the materials is etched away to produce a slotted surface structure. These slots can add size and shape selectively to separations and catalytic processes which because of the uniform and controllable dimensions (>5A) would be superior to that obtainable from zeolites and clays.
Type:
Grant
Filed:
July 1, 1985
Date of Patent:
October 20, 1987
Assignee:
Exxon Research and Engineering Company
Inventors:
Harry W. Deckman, Richard B. Stephens, J. Thomas Tiedje, Benjamin Abeles
Abstract: The present invention is a method and the microorganism and enzyme used therein to degrade the Xanthan molecule. The microorganism is a soil bacterium, Bacillus sp. The method includes using the mixed culture, or a supernatant derived therefrom or the purified enzyme itself.
Abstract: A high surface area substrate with controlled pore size and slot geometry is used in an adsorbing process. The material is made by depositing at least two materials in alternating layers. The film is then broken up and one of the materials is etched away to produce a slotted surface structure. These slots can add size and shape selectivity to separations and catalytic processes which because of the uniform and controllable dimensions (>5A) would be superior to that obtainable from zeolites and clays.
Abstract: A process for dissolving PuO.sub.2, NpO.sub.2, or fuel containing PuO.sub.2 and/or NpO.sub.2 in acid, particularly nitric acid by electrolytically continuously maintaining an oxidizing regenerable reagent. The regenerable reagent may be added to the mixture of oxide(s) and nitric acid. Alternately, it may already be present as a fission product or other nuclear reaction product in irradiated nuclear reactor fuel, in which case it need not be added to the nitric acid.
Type:
Grant
Filed:
September 26, 1984
Date of Patent:
August 11, 1987
Assignee:
Exxon Research and Engineering Company
Inventors:
Jack L. Ryan, Lane A. Bray, Allyn L. Boldt
Abstract: The present invention is an X-ray mirror including a multi-layered material in which the composition of the layers repeat, the repeat distance being between 8 and 250 A., In one embodiment, the mirror is produced by CVD. In another embodiment, the layers forming the structure are made of amorphous semiconductor or insulator material.
Type:
Grant
Filed:
November 20, 1984
Date of Patent:
August 4, 1987
Assignee:
Exxon Research and Engineering Company
Inventors:
Benjamin Abeles, Wolfgang U. Eberhardt, J. Thomas Tiedje
Abstract: A thin film photoconductive device with a substrate structure of "correlated roughness" is disclosed for enhancing the absorption of solar light.
Abstract: A method of doping amorphous semiconductor films have a first bandgap by forming the first bandgap amorphous material in a first plurality of spaced apart layers; and then forming a second plurality of semiconductor layers of amorphous material having a second bandgap wider than the first bandgap interleaved with and contiguous with the first plurality such that the conductor and valence band step at the interfaces between the first plurality and the second plurality is of sufficient magnitude to confine carriers. The second plurality is doped such that the electrons in the gap states from the second plurality of layers transfer to the first plurality of layers and cause the conductivity of said first plurality to increase.
Abstract: The present invention is a method and a device for the frequency modulation and/or demodulation of a signal applied to materials that carry sliding charge density waves. A particular example of such a material is orthorhombic TaS.sub.3 that acts as a frequency modulator.
Type:
Grant
Filed:
July 8, 1985
Date of Patent:
January 13, 1987
Assignee:
Exxon Research and Engineering Company
Inventors:
Sabyasachi Bhattacharya, Aaron N. Bloch, James P. Stokes
Abstract: A system for measuring fluorescence-suppressed Raman Scattering using intensity-modulated laser excitation, electro-optic demodulation of the emitted and scattered light, and a means to adjust the phase of optical transmission of the demodulator relative to the laser modulation.
Abstract: The invention teaches a method for measuring the temperature of remote hot samples in the presence of ambient radiation. A portion of the surface of the sample is treated to obtain a spectral emissivity different from the untreated surface. The spectral radiances of the treated and untreated surface portions are measured and the temperature calculated from these values and the known emissivities.
Abstract: A method is described for producing an electronically passivated stable surface on silicon wafers. The passivation technique consists of first fluorinating the surface of a crystalline silicon wafer under inert atmospheric conditions. Such a treatment may consist of either a vapor phase or liquid phase application of HF at room temperature. The surface fluorinated wafer is then maintained in an inert atmosphere and a thin coating of an organic solid is applied to the wafer which does not disturb the underlying passivated silicon surface. The wafer may then be further processed into a variety of different devices.
Type:
Grant
Filed:
October 5, 1984
Date of Patent:
August 26, 1986
Assignee:
Exxon Research and Engineering Co.
Inventors:
Bernard R. Weinberger, Harry W. Deckman, Eli Yablonovitch
Abstract: The present invention is a method to increase the sensitivity of a positive polymer resist by control of molecular weight distribution and prebake temperature. The sensitivity of a polymer positive resist is increased by baking a narrow molecular weight fraction resist below the glass transition temperature. More particularly the sensitivity is increased by the use of low average molecular weight resist of narrow molecular weight distribution.
Abstract: The present invention is a method to increase the contrast of a positive polymer resist by control of molecular weight distribution and prebake temperature. The contrast of a positive polymer resist is increased by baking a narrow molecular weight fraction resist above the glass transition temperature. More particularly the contrast is increased by the use of low average molecular weight resist of narrow molecular weight distribution.
Abstract: A semiconductor device which includes an active region including a superlattice amorphous material wherein the energy gap has a predetermined value. A preferred embodiment of the device is a solar cell. In another embodiment of the present invention, the device is a tandem solar cell which includes a first active region including a superlattice material wherein the bandgap has a first predetermined value; a second active region including a second superlattice material wherein the bandgap has a second predetermined value different from said first predetermined value; a means for electrically interconnecting said first and second active regions such that current may flow between said first and second active regions.
Abstract: Piezoelectric transducers and oscillators made from amorphous superlattice structures are disclosed. These materials have large built-in fields necessary for piezoelectricity but they are materials which can be deposited at low temperatures onto virtually any substrate.
Abstract: A purified hydroxylase enzyme component A of the methane monooxygenase enzyme isolated from the soluble fraction of Methylobacterium organophilum (CRL.26) (NRRL B-11,222) is found to contain three subunits. Any component A derived from methylotrophs having the particular characteristics of this isolated component A may be employed in conjunction with the flavoprotein component C of the methane monooxygenase enzyme, preferably the flavoportein component derived from the same organism, to catalyze the oxidation of various oxidizable organic substrates to their respective oxidation products. Preferably, the substrate is propylene.
Abstract: The present invention is a method and a device for the frequency modulation and/or demodulation of a signal applied to materials that carry sliding charge density waves. A particular example of such a material is orthorhombic TaS.sub.3 that acts as a frequency modulator.
Type:
Grant
Filed:
July 26, 1984
Date of Patent:
April 1, 1986
Assignee:
Exxon Research and Engineering Co.
Inventors:
Sabyasachi Bhattacharya, Aaron N. Bloch, James P. Stokes
Abstract: A contactless rf technique for measurement of the carrier lifetime from the photoconductivity induced in silicon wafers by a flash of infrared light. The carrier lifetime is inferred from the photoconductivity decay.
Abstract: The present invention is a method for producing an optically enhanced thin film photovoltaic device.The method includes the steps of producing an active layer of semiconductor material wherein the surface of at least one side of the active layer is textured such that the surface includes randomly spaced, densely packed microstructures of predetermined dimensions of the order of the wavelength of visible light in the semiconductor material and attaching a reflecting surface directly to one side of the semiconductor material and making an ohmic contact to the material.
Type:
Grant
Filed:
May 22, 1984
Date of Patent:
November 26, 1985
Assignee:
Exxon Research & Engineering Company
Inventors:
Harry W. Deckman, Horst Witzke, Christopher Wronski, Eli Yablonovitch
Abstract: The present invention relates to a method for the production of refractory oxide powders by pyrolyzing with laser energy a metal- and oxygen-containing organic chemical species characterized by the following properties: (a) some or all of the organic fragments (ligands) are bound to the metal by one or more metal-oxygen bonds, (b) the chemical species is able to absorb laser energy, preferably from a CO.sub.2 laser, in a vibrational mode, (c) the chemical species can be obtained in a gas state, at a temperature below the decomposition temperature.