Abstract: An automated irrigation purge system utilizes a pressure purge method of discharging compressed air from a reservoir through selected irrigation zones with feedback from pressure switches to determine when to open and close each zone valve. No programming or user interaction is required beyond starting the system. The system can operate with a wide variety of irrigation systems, with varying number of zones, pipe lengths, pipe diameters, number and variety of sprinkler heads or outlets, and terrain slope. The system tracks the pressure transition time from high pressure to low pressure for each zone as it is blown out. When the current transition time is within a specified range from the previous transition time, the system knows the water has been sufficiently purged from that zone. The purge system can protect the irrigation system from high-pressure conditions, handle multiple error conditions, and maintain water valve settings during power loss.

Abstract: An automated irrigation purge system utilizes a pressure purge method of discharging compressed air from a reservoir through selected irrigation zones with feedback from pressure switches to determine when to open and close each zone valve. No programming or user interaction is required beyond starting the system. The system can operate with a wide variety of irrigation systems, with varying number of zones, pipe lengths, pipe diameters, number and variety of sprinkler heads or outlets, and terrain slope. The system tracks the pressure transition time from high pressure to low pressure for each zone as it is blown out. When the current transition time is within a specified range from the previous transition time, the system knows the water has been sufficiently purged from that zone. The purge system can protect the irrigation system from high-pressure conditions, handle multiple error conditions, and maintain water valve settings during power loss.

Abstract: An automated irrigation purge system utilizes a pressure purge method of discharging compressed air from a reservoir through selected irrigation zones with feedback from pressure switches to determine when to open and close each zone valve. No programming or user interaction is required beyond starting the system. The system can operate with a wide variety of irrigation systems, with varying number of zones, pipe lengths, pipe diameters, number and variety of sprinkler heads or outlets, and terrain slope. The system tracks the pressure transition time from high pressure to low pressure for each zone as it is blown out. When the current transition time is within a specified range from the previous transition time, the system knows the water has been sufficiently purged from that zone. The purge system can protect the irrigation system from high-pressure conditions, handle multiple error conditions, and maintain water valve settings during power loss.

Abstract: An automated irrigation purge system utilizes a pressure purge method of discharging compressed air from a reservoir through selected irrigation zones with feedback from pressure switches to determine when to open and close each zone valve. No programming or user interaction is required beyond starting the system. The system can operate with a wide variety of irrigation systems, with varying number of zones, pipe lengths, pipe diameters, number and variety of sprinkler heads or outlets, and terrain slope. The system tracks the pressure transition time from high pressure to low pressure for each zone as it is blown out. When the current transition time is within a specified range from the previous transition time, the system knows the water has been sufficiently purged from that zone. The purge system can protect the irrigation system from high-pressure conditions, handle multiple error conditions, and maintain water valve settings during power loss.

Abstract: A fuel cell system includes a fuel cell stack, which during operation generates electrical energy by reacting a first stream of reactant gas and a second stream of reactant gas. The fuel cell stack also produces a fuel cell exhaust stream. An oxidizer unit is positioned to receive the fuel cell exhaust stream and oxidize at least a part of the fuel cell exhaust stream during operation, to produce an oxidizer exhaust stream. A heat recovery system is positioned to receive the oxidizer exhaust stream. The heat recovery system transfers at least some heat from the oxidizer exhaust stream to an input stream to generate a heated stream of water. In some embodiments, a temperature sensor is positioned to sense the temperature of the heated input stream. A control system maintains the heated stream of water at a target temperature based on the sensed temperature by controlling the amount of the heat from the oxidizer exhaust stream that is transferred to the input stream.

Abstract: A track image read/write head buffer provides a buffer memory for each read/write head in the rotating media data storage system so that a seek request from the processor can be handled as soon as the beginning of the requested data record is positioned below the associated read/write head. The data image of the entire data storage track that contains the requested data record stored on the rotating media is read from the rotating media by the read/write head and stored in the track image read/write head buffer independent of the availability of a data communication path to the processor. Thus, the read data operation need not be synchronized with the availability of a data communication path to the processor and the requested data record is retrieved from the rotating media as soon as the data record is properly positioned. In no case is the data retrieval time greater than one revolution of the rotating media.

Abstract: The address mark triggered read/write head buffer provides a buffer memory for each read/write head in the rotating media data storage system that stores the entire track of data that includes the requested data record. Thus, the address mark triggered read/write head buffer retrieves the requested data record independent of the control module so that a seek request from the processor can be handled as soon as the beginning of the next data record stored on the track is positioned below the associated read/write head. The entire track is thereby staged faster on the average than the time to retrieve the requested data record. The address mark triggered read/write head buffer includes an address mark detection circuit to identify the beginning of the data field in each data record. The address mark is a predetermined data pattern of n bits that is written on the track a predetermined distance in advance of the data field of the data record.

Abstract: The dual port disk drive interface circuit enables a plurality of dual port disk drives to be interconnected with a plurality of control units in a manner that is transparent to both the dual port disk drives and the control unit. The dual port disk drive interface circuit is interposed between the two channels from n control units and the dual ports of m dual port disk drives to switchably interconnect each control unit with an available dual port disk drive. The interface circuit intercepts the control signals that are generated by both the control units and the dual port disk drives and modifies these control signals to emulate the interconnection of each control unit with a dedicated dual port disk drive. The interface circuit controls the routing of data between the control unit and the available ports on the plurality of dual port disk drives to multiply the number of ports available on the dual port disk drive without modification of the control unit or the dual port disk drive.

Abstract: The read/write head buffer provides a buffer memory for each read/write head in the rotating media data storage system to that a seek request from the processor can be handled as soon as the beginning of the requested data record is positioned below the associated read/write head. The data image stored on the rotating media is read from the rotating media by the read/write head and stored in the read/write head buffer independent of the availability of a data communication path to the processor. Thus, the read data operation need not be synchronized with the availability of a data communication path to the processor and the requested data is retrieved from the rotating media as soon as the data record is properly positioned. In no case is the data retrieval time greater than one revolution of the rotating media. The error correction codes written on the rotating media to protect the integrity of the requested data are maintained since they are stored in the read/write head buffer along with the data record.

Abstract: Progressive step and compound dies are employed in a cold working process to form a metallic preform of selected mass into a precision-finished, pore-free, annular bushing with a mass substantially equal to that of the preform for use as a battery terminal which allows the fracture free spin over connection of the stem of the bushing to a battery cover and the close fit of the bushing on the battery post when the cover is fitted to the battery casing.

Abstract: Conformal layers of a silicon oxide, such as silicon dioxide, are deposited at temperatures below 600 degrees C. through the decomposition of compounds such as diacetoxyditertiarybutoxysilane. The required temperatures do not significantly affect temperature-sensitive structures. Therefore, it is possible to form silicon oxide regions in the processing of devices having these structures. More generally, lowered-temperature processing can be applied to the deposition of other materials which include silicon oxide. For example, borophosphosilicate glasses can be deposited by chemical vapor deposition processing involving flash-evaporation of a mixture of liquid precursor reagents.

Abstract: Conformal layers of a silicon oxide, such as silicon dioxide, are deposited at temperatures below 600 degrees C. through the decomposition of compounds such as diacetoxyditertiarybutoxysilane. The required temperatures do not significantly affect temperature-sensitive structures. Therefore, it is possible to form silicon oxide regions in the processing of devices having these structures.

Abstract: Compact apparatus characterized by cleanliness of operation, high throughput and low cost is designed for automatically loading and unloading wafer-carrying trays that are designed to be mounted in the reaction chamber of a processing system. A key component of the apparatus comprises a unique wafer vacuum chuck.

Abstract: At least three spring-mounted members disposed around the periphery of an aperture in a wafer-mounting plate are arranged to engage and securely hold edge portions of a semiconductor wafer to be processed. When the spring-mounted members are actuated toward the front side of the plate, a wafer can be freely moved into or out of the aperture from the back side of the plate by means of a vacuum chuck that contacts only the back side of the wafer. After a wafer to be held is inserted within the aperture, the actuated members are released. The released members move toward the back side of the plate and thereby engage the edges of the inserted wafer and exert radial holding forces thereon. The back side of a wafer so mounted is adapted to be brought into resilient engagement with a pedestal element in a processing chamber, thereby ensuring good thermal and electrical contact between the wafer and the pedestal element.

Abstract: X-ray lithographic systems as heretofore constructed include a low-attenuation chamber for propagating x-rays from a source toward a mask member that is positioned in close proximity to a resist-coated wafer. Both the mask and the wafer are included in the chamber which typically is either filled with helium or evacuated to a pressure less than about 10.sup.-2 Torr. In accordance with this invention, an x-ray lithographic system is constructed to enable establishment in the wafer-to-mask region of a controlled atmosphere that is separate and distinct from that maintained in the low-attenuation chamber. In this way, an improved lithographic system with advantageous throughput and other characteristics is realized.