Exxon Research and Engineering Company

Brian P Flannery

Harry William Deckman

Wayne G Roberge

Robert J Chimenti

Anthony E Cerkanowicz

Peter Michael Eisenberger

Irving D Crane, Jr

The present invention is a method for examining at least a portion of an object using penetration radiation. The method includes the steps of transmitting radiation from an external source through the object in a plurality of coplanar rays, detecting the attenuated transmitted radiation after it has passed through the object, determining the projection data for said rays, and inverting said projection data to generate the distribution of the attenuation coefficient, wherein said inverting step includes the Direct Fourier Inversion Method such that the projection data is padded and the Fourier coefficients are filtered.

Method for producing tomographic images using direct Fourier inversion

The present invention is an apparatus and a method for producing tomographic images of an object irradiated by a beam of collimated radiation transmitted in a plurality of rays through a set of coplanar sections of an object as viewed from a plurality of angles about a rotation axis. The apparatus includes an imaging electro-optic detector to record the transmitted radiation, wherein the electro-optic detector alters the image format, the format alteration being focused; means to determine and align the projected position of the rotation axis on the electro-optic detector; means to align the object with respect to the rotation axis; means to determine and assure spatial uniformity of detector response; means to reduce signal dependent backgrounds; means to determine the projection coefficients from the transmitted radiation with respect to one or more reference calibration exposures; and means to compute a reconstructed image of the object's attenuation coefficients.

Method and apparatus for utilizing an electro-optic detector in a

The present invention is an apparatus for producing tomographic images of an object comprising: a beam of collimated radiation transmitted through the object in a plurality of rays, an imaging electro-optic detector for detecting the attenuated transmitted radiation after it has passed through the object, the detector including an energy convertor, image format altering device, and a readout device, wherein the detector has a detective quantum efficiency greater than 0.05, a total signal dependent background less than 10 percent of the signal from the unattenuated x-ray beam, a useful dynamic range greater than 10, a non-uniformity of response between adjacent active pixels of less than 75%, and deviations of geometric linearity that is less than 10 pixels in the recorded image, means for obtaining the attenuation coefficients from the transmitted radiation, and means for computing a reconstructed image of the object from the attenuation coefficients.

Apparatus for three dimensional tomography utilizing an electro-optic

To promote nucleation of a solute in a solution (e.g. wax dissolved in lubricating oil), free excess charge which is net unipolar is introduced into the solution, for example by charge injection, and the solubility for the solute is reduced (for example by cooling), at least until nucleation of the solution takes place. Nucleation is the physical mechanism which leads to precipitation of the solute and so this method can be applied for the electrical pretreatment of the solution to produce a precipitate, following which the precipitate can be removed from the solvent by conventional separation techniques or be present to provide desired physical or chemical characteristics. An alternative method is to reduce the solubility of the solute in the solution almost to the point of nucleation, and only then to introduce the free excess charge so as to precipitate the onset of nucleation.

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Clinton, NJ, United States of America

Brian P Flannery