Abstract: A method for porosity determination in porous media such as earth and rock core samples by x-ray computed tomography in which a sample of the porous medium is scanned after saturation with a first reference fluid and then after saturation with a second reference fluid to determine the linear attenuation coefficients of the sample saturated with the respective fluids. The method includes determining the linear attenuation coefficients of the respective fluids and comparing the difference in the attenuation coefficient of the respective fluids and the attenuation coefficient of the samples as saturated with the fluids to determine the porosity of the porous medium. The respective fluids may be a gas and a liquid wherein the x-ray absorption of the two fluids is significantly different. The fluids may be different liquids or a single gas at different pressure conditions to obtain the different absorption characteristics.

Abstract: A geologic core holder includes an elongated barrel constructed of a composite of wound and longitudinally extending nonmetallic fibers embedded in a resin matrix to provide a high strength structure which presents minimal attenuation of x-rays and magnetic flux. The barrel has opposed end flanges and the core holder includes removeable end plugs which are slideable in a bore formed by the barrel. Opposed pairs of split retaining blocks are engageable with the end flanges for securing the end plugs in the barrel bore. One of the end plugs is adapted to support a flexible sleeve for holding the core sample within a cavity formed in the barrel bore whereby fluid pressure may be applied to exert a particular pressure and temperature condition on the core so that pressure fluid flow characteristics through the core may be studied and x-ray imaged.

Abstract: An apparatus for collecting solar energy and converting it to electrical energy utilizing solar panels pivotally mounted to a base such that the panels may be pivoted to a storage position inside said base. Additional solar panels may be pivotally mounted on retractable frame trays which stow inside the base when the panels are pivoted to a horizontal position.

Abstract: An apparatus for collecting solar energy and converting it to electrical energy utilizing solar panels pivotally mounted to a base such that the panels may be pivoted to a storage position inside said base. Additional solar panels may be pivotally mounted on retractable frame trays which stow inside the base when the panels are pivoted to a horizontal position.