Abstract: An electrically-actuated variable pressure control system for use with flow-controlled liquid application systems. Direct acting solenoid valves are pulsed at varying frequencies and duty cycles to change the resistance to flow encountered by the flow-controlled liquid application system. This pulsing solenoid valve technique preserves a high degree of accuracy and uniformity through a wide range of pressure control. This wide range of pressure control indirectly allows the flow-controlled liquid application system to operate over a wider range of flow control, yielding indirect benefits to performance and productivity. When the solenoid valves are attached to pressure-atomization spray nozzles, control over spray pattern and droplet size is further achieved.

Abstract: A system and process for dispensing a liquid agrochemical such as ammonia into a field is disclosed. The ammonia is placed in a vessel under sufficient pressure to maintain a substantial portion of the ammonia in a liquid form. From the pressurized vessel, the ammonia is fed to a distribution manifold where it is ultimately injected into a soil through a plurality of dispensing tubes. A constant pressure flow rate control device is placed at each dispensing tube for metering the amount of ammonia fed to the soil. Furthermore, the outlet flow of each constant pressure rate control device is made to vaporize nearby the inlet flow path to create a heat exchange effect thereby cooling the inlet flow. In particular, the flow control devices allow ammonia to be dispensed from the system while maintaining sufficient back pressure and temperature within the distribution manifold to maintain the ammonia in a liquid form.

Abstract: An optical amplifier comprises a pumped doped fiber with a power measurement circuit for measuring the input and output power of the amplifier. Automatic gain control is implemented, and the calculation of output power for the AGC loop takes into consideration the temperature provided by a temperature measurement device. This enables a flatter gain response to be achieved over varying input power, which enables an increase in the dynamic range of the amplifier and thereby a possible increase in system capacity of a WDM system using the amplifier.