Abstract: The disclosure is directed to a cooling system that includes a first refrigerant cycle and a second refrigerant cycle. The first refrigerant cycle has a first refrigerant and the second refrigerant cycle has a second refrigerant comprising a mixture of cryogenic components. The disclosure is also directed to a cooling system that includes a first refrigerant cycle and a second refrigerant cycle. The first refrigerant cycle has a first refrigerant. The second refrigerant cycle has a second refrigerant comprising a non-reactive component. The second refrigerant is free of fluorocarbons, chlorofluorocarbons, and hydrocarbons. At least a portion of the second refrigerant is condensed in the second refrigerant cycle.

Abstract: A method for billing customers over the Internet or other means of electronic communication between an access provider and a customer for use of services. The provider creates access to measurement data obtained by the customer for electronic data loggers which have been programmed for one time use by the manufacturers, distributor or agent for use by the customer or customers. A unique identity is embedded within the measurement device so that the provider can associate measurement data and/or billing information with the customer or end user. The provider then bills the transaction to either the user's account or those of designated account holders. This method for billing customers is applicable for all sensor based technologies to include temperatures, humidity, pressures, light, events, voltage, acceleration, shock, strain, flows and any other discipline where electronic sensors are embedded in devices programmed for one-time use and used in either remote locations or during transportation.

Abstract: Method and apparatus to ensure the confidentiality of electronic documents by tracking the accessing/use of electronic documents.

Abstract: A shell and coil type heat exchanger evaporator provides cooling for industrial coolants characterized by high viscosity and a poor heat transfer coefficient. A large heat transfer surface area is provided within a limited volume, and without a high coolant pressure drop. A short initial cool down period is provided due to minimized heat exchanger mass and minimized volume of liquid coolant in the heat exchanger during initial cool down.

Abstract: The present invention is a refrigeration system that uses a nonflammable, nonchlorinated refrigerant mixture to achieve very-low temperatures using a single compressor. The system is characterized by both high efficiency and rapid cool down time.

Abstract: A shell and coil type heat exchanger evaporator provides cooling for industrial coolants characterized by high viscosity and a poor heat transfer coefficient. A large heat transfer surface area is provided within a limited volume, and without a high coolant pressure drop. A short initial cool down period is provided due to minimized heat exchanger mass and minimized volume of liquid coolant in the heat exchanger during initial cool down.

Abstract: Refrigerant freezeout is prevented by the use of a controlled bypass flow that causes a warning of the lowest temperature refrigerant in a refrigeration system that achieves very low temperatures by using a mixture of refrigerants comprising at least two refrigerants with boiling points that differ by at least 50° C. This control capability enables reliable operation of the very low temperature system.

Abstract: The present invention is a refrigeration system that uses a nonflammable, nonchlorinated refrigerant mixture to achieve very-low temperatures using a single compressor. The system is characterized by both high efficiency and rapid cool down time.

Abstract: Heating/defrost constructions of a very low temperature refrigeration system having a defrost supply circuit and a defrost return bypass circuit optimizing the heating/defrost cycle, preventing overload (excessive pressure) of its refrigeration process and protecting components from damaging temperatures. The defrost cycle operates continuously, when required, and provides a shorter recovery period between heating/defrost and cooling operating modes. The rate of the temperature change during cool down or warm up is controlled in an open loop fashion by controlled refrigerant flow in bypass circuits.

Abstract: A standard refrigeration pressure regulating valve limits the minimum temperature produced by a refrigeration process, which uses a refrigerant mixture including at least two components whose normal boiling points differ by at least 50C. Limiting the lowest temperature prevents freezout of the individual refrigerant.

Abstract: Refrigerants containing HCFC's are replaced with new blends by using R-236fa and R-125, or R-125 with R-245fa, or R-236ea, or R-134a with R-236fa in place of HCFC's. No hardware or oil composition changes are required to maintain temperatures, pressures and capacity substantially unchanged in a refrigeration system.

Abstract: Flow in a forward direction through a check valve is detected by a signaling device in parallel with the check valve and sensing the pressure differential across the check valve. The signaling device outputs an electrical signal that indicates whether or not the pressure differential across the valve is sufficient to open the valve to flow. A flow restrictor such as a capillary tube is in parallel with the check valve to by-pass a small portion of flow during normal operation and to equalize pressure across the check valve inlet and outlet when the check valve is otherwise closed to flow.

Abstract: Refrigerants containing HCFC's are replaced with new blends by using R-236fa and R-125, or R-125 with R-245fa, or R-236ea, or R-134a with R-236fa in place of HCFC's. No hardware or oil composition changes are required to maintain temperatures, pressures and capacity substantially unchanged in a refrigeration system.

Abstract: A standard refrigeration pressure regulating valve limits the minimum temperature produced by a refrigeration process, which uses a refrigerant mixture including at least two components whose normal boiling points differ by at least 50 C. Limiting the lowest temperature prevents freezout of the individual refrigerant.

Abstract: The present invention is a refrigeration system that uses a nonflammable, nonchlorinated refrigerant mixture to achieve very-low temperatures using a single compressor. The system is characterized by both high efficiency and rapid cool down time.

Abstract: Heating/defrost constructions of a very loW temperature refrigeration system having a defrost supply circuit and a defrost return bypass circuit optimizing the heating/defrost cycle, preventing overload (excessive pressure) of its refrigeration process and protecting components from damaging temperatures. The defrost cycle operates continuously, when required, and provides a shorter recovery period between heating/defrost and cooling operating modes. The rate of the temperature change during cool down or warm up is controlled in an open loop fashion by controlled refrigerant flow in bypass circuits.

Abstract: Flow in a forward direction through a check valve is detected by a signaling device in parallel with the check valve and sensing the pressure differential across the check valve. The signaling device outputs an electrical signal that indicates whether or not the pressure differential across the valve is sufficient to open the valve to flow. A flow restrictor such as a capillary tube is in parallel with the check valve to by-pass a small portion of flow during normal operation and to equalize pressure across the check valve inlet and outlet when the check valve is otherwise closed to flow.

Abstract: A card reader located in proximity to the central point of the secured area having a crystal controlled time base clock. Entry is granted when the proper information is entered to the card reader through a keypad or identification card. The clock is adjusted under software control according to a selected offset signal. The card reader is operable to provide access control of a secured area according to a schedule operable relative to the card reader clock without external reference signals.