Abstract: A pressure swing adsorption (PSA) dryer for separating water and carbon dioxide from a gas stream includes two compound adsorbent columns [32, 42]. Each column comprises a primary adsorption material for adsorbing water and a secondary adsorbent that adsorbs carbon dioxide. The secondary adsorbent comprises a solid amine. The secondary adsorbent may be, for example, a highly porous polystyrene matrix with amine groups bonded to the porous resin structure. Preferably, a mixture of the primary and secondary adsorbent materials forms an intermediate layer [38, 48] sandwiched between a top layer [34, 44] and bottom layer [36, 46] of pure water adsorbent material in each of the columns [32, 42].

Abstract: A cryogenic gas is liquefied using a refrigeration system [101] thermally coupled at an evaporator [125] to a cold end of a gas supply system [103] within a dewar [116]. The refrigerator has a minimum temperature at an evaporator [125] above the boiling point of the gas at atmospheric pressure but below the boiling point of the gas at a high pressure. Thus, the gas is compressed [128] to high pressure so it condenses when cooled by the evaporator [125]. As it expands at a flow restrictor [148], a portion evaporates and cools a fraction to the temperature of the boiling point of the gas at atmospheric pressure, producing liquefied gas. Opening a purge valve [142] sends warm gas upward through heat exchange section [146] and out through a three-way valve [138] for defrosting. To reduce clogging, the gas supply valve [138] is controlled by a gas purity sensor [158].

Abstract: A formulation to produce urethane linkages reacts cyclocarbonate groups with diamines. Aliphatic polyhydroxyl precursor molecules are first epoxidized. The invention does not require complete epoxidation, as it makes use of the un-epoxidized hydroxyl groups of the precursor molecule. These hydroxyl groups are combined with isocyanate groups of prepolymer molecules to form urethane links. The use of prepolymers increases the networking, flexibility, and impact-resistance of the final product. The known formulations for amine hardeners also require complete carbonation of the epoxy groups to form reactive cyclocarbonate groups, which are reacted with diamines to form an amine hardener. In the proposed invention, both cyclocarbonate and epoxy groups are used to combine with the different diamine molecules by making use of the different reactivities of aliphatic, cycloaliphatic, and aromatic amine groups.

Abstract: Physical properties such as composition, purity, or doping level of a sample surface can be measured and imaged using the apparatus and method disclosed herein. Imaging is performed by the following steps:1) illuminating the sample surface with uniform, monochromatic light and capturing a first image of the reflected light with a CCD camera,2) uniformly and precisely changing a physical parameter of the sample,3) repeating step 1 to capture a second image influenced by the new value of the physical parameter,4) subtracting the first and second images and dividing the result by the average of the images to produce a normalized difference image.The physical parameter may be temperature, as in the preferred embodiment, electric field, light exposure (at a wavelength different from that used to obtain the image), magnetic field, or mechanical stress. The image produced is of the differential reflectance of the sample surface at a given wavelength.

Abstract: A mixture comprising epoxidized liquid rubbers, amine hardeners and sulfur applied to a metal and cured produces a coating that is highly durable and provides strong anticorrosive protection to the metal. The amine hardeners serve to activate and dissolve the sulfur, speed up the curing time, and also bond to the rubbers to create a continuous molecular matrix. The activated sulfur also links the rubber molecules together, as well as anchoring the polymer matrix to the metal substrate via chemical bonds. In a preferred embodiment, the formulation also includes two types of accelerators which act synergistically to further reduce the curing time to less than one hour. The addition of micronized aluminum oxides provides increased uniformity of heating during curing and results in a more uniform coating. The addition of calcium oxide together with the presence of amines and aluminum oxide provides a complete absorption of acidic gases produced during curing.

Abstract: A method and device is disclosed for removing residual oil and other contaminants from the refrigerant stream flowing to low-temperature stages of a cryogenic refrigerator. A stream of vapor and liquid refrigerant is injected into a cyclone chamber ?32! through the inlet tube ?34!. While the liquid drains down a conical section ?36! and out through a liquid line ?38!, the vapor phase moves up into a packing of metal platelets ?42! which is, in a particular embodiment, cooled by a returning stream of cold vapor passing through a tube ?48! wrapped around the column. A portion of the vapor condenses on the platelets and is maintained in equilibrium with the vapor. Since high-molecular-weight contaminants are more soluble in the liquid phase, they are carried down the column with the drops of condensate and are swept out with the liquid fraction through the liquid line ?38!.

Abstract: A method is disclosed for maximizing the thermodynamic efficiency and the heat transfer capacity of a counter-current heat exchanger through the use of an optimized multi-component working fluid. Given the operational temperatures and pressures of the heat exchanger, the disclosure teaches a method for selecting the components for the working fluid and for determining the molar fractions of the components that determine the optimal mixture for the working fluid. Because the effective specific heat of a high pressure stream of this mixture is equal to the effective specific heat of a low pressure stream throughout the entire temperature range of the heat exchanger, the thermodynamic efficiency of the heat exchange process is maximized. In addition, because the difference between the enthalpies per unit mass of the two streams are maximized throughout the temperature range of the exchanger, this mixture provides optimal capacity for heat transfer in the heat exchanger.

Abstract: A method and device is disclosed for removing residual oil and other contaminants from the refrigerant stream flowing to low-temperature stages of a cryogenic refrigerator. A stream of vapor and liquid refrigerant coming from an air-cooled condenser is injected into a cyclone chamber [32] through the inlet tube [34]. While the liquid drains down a conical section [36] and out through a liquid line [38], the vapor phase moves up into a packing of metal platelets [42] which is cooled by a returning stream of cold vapor passing through a tube [48] wrapped around the column. A portion of the vapor condenses on the platelets and is maintained in equilibrium with the vapor. Since high-molecular-weight contaminants are more soluble in the liquid phase, they are carried down the column with the drops of condensate and are swept out with the liquid fraction through the liquid line [38].