Abstract: An article includes a piece of encapsulated insulation including an envelope having at least two vents therethrough, a particulate insulation within the envelope, and a porous filter overlying each vent of the envelope. The porous filter has a mesh size no larger that the minimum size of the particles. The article may further include a structure having a structure surface, and the piece of encapsulated insulation overlies and covers at least a portion of the structure surface.

Abstract: An article includes a piece of encapsulated insulation including an envelope having at least two vents therethrough, a particulate insulation within the envelope, and a porous filter overlying each vent of the envelope. The porous filter has a mesh size no larger that the minimum size of the particles. The article may further include a structure having a structure surface, and the piece of encapsulated insulation overlies and covers at least a portion of the structure surface.

Abstract: Liquid CO2 is expanded in specially designed primary and secondary nozzles to produce frozen solid CO2. The impurities initially contained in the liquid CO2 are trapped inside of the frozen CO2, which is collected in a clean container. The container is emptied on top of a high purity surface. The impurities are concentrated on the surface, since these impurities are non-volatile and do not escape with the CO2 gas formed as the frozen CO2 is heated by the ambient temperature to its sublimation point. After all of the frozen CO2 has sublimed, the surface can be analysed by standard analysis methods to determine quantity and composition of the impurities. The determination and quantification of non-volatile impurities, such as organic oils and greases, in the CO2 supply that feeds, for example, cleaning systems utilizing CO2, is thus made possible.

Abstract: Liquid CO2 is expanded in specially designed primary and secondary nozzles to produce frozen solid CO2. The impurities initially contained in the liquid CO2 are trapped inside of the frozen CO2, which is collected in a clean container. The container is emptied on top of a high purity surface. The impurities are concentrated on the surface, since these impurities are non-volatile and do not escape with the CO2 gas formed as the frozen CO2 is heated by the ambient temperature to its sublimation point. After all of the frozen CO2 has sublimed, the surface can be analysed by standard analysis methods to determine quantity and composition of the impurities. The determination and quantification of non-volatile impurities, such as organic oils and greases, in the CO2 supply that feeds, for example, cleaning systems utilizing CO2, is thus made possible.

Abstract: Liquid CO2 is expanded in specially designed primary and secondary nozzles to produce frozen solid CO2. The impurities initially contained in the liquid CO2 are trapped inside of the frozen CO2, which is collected in a clean container. The container is emptied on top of a high purity surface. The impurities are concentrated on the surface, since these impurities are non-volatile and do not escape with the CO2 gas formed as the frozen CO2 is heated by the ambient temperature to its sublimation point. After all of the frozen CO2 has sublimed, the surface can be analysed by standard analysis methods to determine quantity and composition of the impurities. The determination and quantification of non-volatile impurities, such as organic oils and greases, in the CO2 supply that feeds, for example, cleaning systems utilizing CO2, is thus made possible.

Abstract: A CO2 jet spray nozzle comprising multiple nozzle orifices for use in producing CO2 jet spray. The nozzle comprises a body, an elongated nozzle tube extending from the body having an axial hole therein, and an orifice disk disposed at the base of the nozzle tube in the axial hole. The orifice disk contains a plurality of orifices disposed therein that form a critical orifice and that is an integral part of the nozzle. The orifices may be drilled by means of a laser beam or electron discharge machining through the orifice disk. The orifice disk and nozzle tube are typically welded together to prevent leakage. By fabricating different nozzles in which the orifice size, orifice geometry (round, oval, or elongated slit), total orifice area, nozzle diameter and nozzle length is varied within a well defined matrix, any intensity of CO2 jet spray may be obtained. By varying the arrangement of the orifices, nozzle geometry, and nozzle length, different spray patterns may be provided.

Abstract: Apparatus for cleaning a moving pallet and components carried thereby. The apparatus includes a processing system that employs the moving pallet. An environmental cleaning station is provided through which the pallet moves. The cleaning station includes a recirculating blower system and a high efficiency particulate air filter. A ducting system or warm air system may be provided for supplying purified air, inert gas, or warm air to eliminate condensation. A carbon dioxide jet spray cleaning system is provided that has jet spray nozzles disposed within the cleaning station that are coupled by way of a manifold to a liquid carbon dioxide tank that supplies liquid carbon dioxide to the jet spray nozzles. The jet spray nozzles generate a carbon dioxide snow spray that impinges on the moving pallet to clean it along with the components it carries.

Abstract: A workpiece is heated by first forming an ionized gas plasma around the workpiece. A positive potential is applied to the workpiece to accelerate electrons from the plasma into the workpiece. The workpiece is uniformly surface heated by the energy directed into the workpiece by the electrons. The workpiece is cooled by providing a flow of a pressurized liquid material such as carbon dioxide having a triple point. The liquid material is expanded through a nozzle to form solid particles that contact the surface of the workpiece and remove heat from it by subliming.

Abstract: A workpiece is heated by first forming an ionized gas plasma around the workpiece. A positive potential is applied to the workpiece to accelerate electrons from the plasma into the workpiece. The workpiece is uniformly surface heated by the energy directed into the workpiece by the electrons. The workpiece is cooled by providing a flow of a pressurized liquid material such as carbon dioxide having a triple point. The liquid material is expanded through a nozzle to form solid particles that contact the surface of the workpiece and remove heat from it by subliming.

Abstract: A system for detecting the presence of contaminants in a flowing stream of supercritical fluid. A sample stream is removed from a flowing stream of supercritical fluid and subjected to reduced pressure in a contaminant measurement zone. The supercritical fluid turns into gas at the reduced pressure with the contaminants remaining in a non-gaseous form. An attenuated total reflectance plate is used to spectrophotometrically detect the presence of the non-gaseous contaminants which deposit on the surface of the plate within the contaminant measurement zone. The system is useful for spectrophotometrically detecting the presence and identity of contaminants in supercritical fluids and is useful in monitoring both cleaning processes and extraction processes.

Abstract: Optical sensing apparatus for use with a CO.sub.2 jet spray nozzle that sprays a plume. The apparatus comprises a coherent light source that provides a light beam. A photodiode is disposed such that it detects the light beam emitted by the coherent light source that passes through the plume sprayed by the CO.sub.2 jet spray nozzle. A bandpass filter is disposed between the photodiode and the coherent light source that only passes light produced by the coherent light source. A controller coupled to the coherent light source and the photodiode that comprises a power supply for providing power to the coherent light source and the photodiode. The controller includes a digital voltmeter coupled to the photodiode for displaying a voltage output signal corresponding to the amount of light energy detected by the photodiode, and a go/no-go indicator for providing an indication of CO.sub.2 snow production.

Abstract: An improved apparatus and method adapted for use in removing trace contaminants from the surface of a chosen substrate, such as delicate surfaces or precision parts, by application of a stream or jet spray of expanded fluid to the substrate surface. The improvement consists of controlling electrostatic charges generated on or near the substrate surface during the cleaning process.

Abstract: An improved apparatus and method for removing trace contaminants from the surface of a chosen substrate, such as delicate surfaces or precision parts, wherein the improvement consists of heating a portion of a chosen substrate surface immediately before, during and/or after application of a stream of cleaning snow to the same portion of the substrate surface.

Abstract: A system for precision cleaning of contaminants from the surface of a substrate, such as delicate surfaces or precision parts, utilizing streams of carbon dioxide snow or other cleaning gas. The system includes an enclosed or sealed cleaning container in which at least one jet spray device is housed for directing a stream of cleaning snow against the surface to be cleaned. During cleaning, the cleaning container holding the substrate to be cleaned is maintained under a vacuum or, optionally, at ambient pressure, filled with a clean dry gas. The dislodged contaminants and spent snow are removed from the cleaning zone and disposed of or recycled. Cleaning is accomplished by pulsed application of the cleaning snow in combination with intermittent or continuous heating of the surface so that the surface is at an elevated temperature prior to and during each application of cleaning snow.

Abstract: An apparatus for controlling the environment of an enclosed space is disclosed. The apparatus includes a workspace compartment within a gas-tight chamber, a mechanism for circulating dehumidified gas in true laminar flow through the workspace compartment, and a highly efficient filtering component for removing contaminants from the gas.

Abstract: A system and method for detecting the presence of contaminants in supercritical fluid. The system is based upon the use of an absorbent module comprising an absorbent which selectively absorbs the contaminant being measured and wherein the electrical properties (i.e. conductance and/or capacitance) of the absorbent varies depending upon the amount of contaminant absorbed. A sample stream of the supercritical fluid is contacted with the absorbent material. By measuring the electrical properties of the absorbent, contaminant levels are measured and monitored.

Abstract: A preceramic substituted borazine polymer of the formula: ##STR1## wherein R is methyl, ethyl, propyl, or butyl, and x is a positive integer. Also disclosed are methods for making the polymer, methods for converting the polymer into coatings, shaped articles, articles including fibers and filaments formed from the polymer, blends of the foregoing polymer and preceramic triamino-N-tris (trialkylsilyl) borazines, and methods for thermally decomposing the foregoing polymers to form shaped articles of boron nitride.

Abstract: Silyl containing cyclic borazines are prepared by reacting chloroborazine with disilazanes.