Abstract: A method to form a displacement includes disposing a powder blend (comprising a plurality of ground ceramic particles and a plurality of ground resin particles) into a mold, densifying the powder blend while in the mold, heating the mold to form a first displacement, impregnating said first displacement with a polymer precursor compound to form a second displacement, and heating the second displacement to form a third displacement.

Abstract: A method to form a displacement includes disposing a powder blend (comprising a plurality of ground ceramic particles and a plurality of ground resin particles) into a mold, densifying the powder blend while in the mold, heating the mold to form a first displacement, impregnating said first displacement with a polymer precursor compound to form a second displacement, and heating the second displacement to form a third displacement.

Abstract: A method to form a displacement, the method including disposing a powder blend comprising a plurality of ground ceramic particles and a plurality of ground resin particles into a mold, densifying the powder blend while in the mold, heating the mold to form a first displacement, impregnating said first displacement with a polymer precursor compound to form a second displacement, and heating the second displacement to form a third displacement.

Abstract: A method to form a displacement for use in a metal casting process, wherein the method provides a plurality of ceramic particles and a plurality of resin particles. The method grinds the plurality of ceramic particles until those ceramic particles comprise diameters less than 150 microns, and grinds the plurality of resin particles until those resin particles comprise diameters less than 100 microns, and forms a powder blend comprising the plurality of ground ceramic particles and the plurality of ground resin particles. The method then disposes the powder blend into a mold comprising a cavity defining the desired displacement. The method further densifies the blend, and cures the resin to form the displacement.

Abstract: A method to form a displacement for use in a metal casting process, wherein the method provides a plurality of ceramic particles and a plurality of resin particles. The method grinds the plurality of ceramic particles until those ceramic particles comprise diameters less than 150 microns, and grinds the plurality of resin particles until those resin particles comprise diameters less than 100 microns, and forms a powder blend comprising the plurality of ground ceramic particles and the plurality of ground resin particles. The method then disposes the powder blend into a mold comprising a cavity defining the desired displacement. The method further densifies the blend, and cures the resin to form the displacement.

Abstract: An analyte chamber which can be releaseably attached to a portable calibration apparatus. The analyte chamber include a wick, one or more analytes disposed in that wick, a housing having an open end, where the wick is internally disposed within that housing, and at least one layer disposed over and enclosing the open end. The analyte chamber does not include a releaseable quantity of the liquid phase of the one more more analytes absorbed in the wick. A method to calibrate an immobile gas detector. The method provides a portable calibration apparatus comprising a portable detector and an analyte chamber comprising a wick, where the analyte chamber is capable of providing one or more concentrations of one or more gases to the portable detector, and where the portable calibration apparatus is capable of providing those one more more gases to the immobile gas detector.

Abstract: A gas sensor comprises a substrate on which are mounted three cells. Each cell includes an interdigitated capacitor defined by a pair of comb structure, electrically conductive tracks with the fingers of the combs interleaved. The tracks of each capacitor are covered by an insulating and chemically inert protective coating of an electrolyte. A monitor monitors one of a resistive component and a capacitive component of the relative dielectric constant of the electrolyte independently of the other component.

Abstract: Gas generating apparatus comprises an electrochemical cell having gas generating (2) and counter electrodes (3) with an intervening body of electrolyte (9). Current passing between the electrodes causes the generation of gas at the gas generating electrode. A first membrane (24) permeable to gas but substantially impermeable to the electrolyte is positioned sufficiently close to the gas generating electrode (2) that gas generated by the gas generating electrode diffuses through the electrolyte and out through the membrane under the influence of a gas concentration gradient, substantially without forming bubbles in the electrolyte and irrespective of the orientation of the apparatus.