Plasma channel optical-pumping device and method (open access)

Plasma channel optical-pumping device and method

A device and method are described for optically pumping a gaseous laser using blackbody radiation produced by a plasma channel which is formed from an electrical discharge between two electrodes spaced at opposite longitudinal ends of the laser. A preionization device which can comprise a laser or electron beam accelerator produces a preionization beam which is sufficient to cause an elctrical discharge between the electrodes to initiate the plasma channel along the preionization path. The optical pumping energy is supplied by a high voltage power supply rather than by the preionization beam. High output optical intensities are produced by the laser due to the high temperature black-body radiation produced by the plasma channel, in the same manner as an exploding wire type laser. However, unlike the exploding wire type laser, the disclosed invention can be operated in a repetitive manner by utilizing a repetitive pulsed preionization device.
Date: July 17, 1981
Creator: Judd, O.P.
Object Type: Patent
System: The UNT Digital Library
Control system for a wound-rotor motor (open access)

Control system for a wound-rotor motor

A load switching circuit for switching two or more transformer taps under load carrying conditions includes first and second parallel connected bridge rectifier circuits which control the selective connection of a direct current load to taps of a transformer. The first bridge circuit is normally conducting so that the load is connected to a first tap through the first bridge circuit. To transfer the load to the second tap, a switch is operable to connect the second bridge circuit to a second tap, and when the second bridge circuit begins to conduct, the first bridge circuit ceases conduction because the potential at the second tap is higher than the potential at the first tap, and the load is thus connected to the second tap through the second bridge circuit. The load switching circuit is applicable in a motor speed controller for a wound-rotor motor for effecting tap switching as a function of motor speed while providing a stepless motor speed control characteristics.
Date: July 17, 1981
Creator: Ellis, James N.
Object Type: Patent
System: The UNT Digital Library
Thermophysical properties of coal liquids. Seventh quarterly technical status report, April 1-June 30, 1981 (open access)

Thermophysical properties of coal liquids. Seventh quarterly technical status report, April 1-June 30, 1981

Measurements of rheological properties have been continued. Measurements at relatively low temperature (450 K) showed that a coarser coal grind shows substantially lower viscosity. It was also shown that coal and solvent obtained from the Fort Lewis plant give slurries of much higher viscosity than slurries from our reference coal and solvent. At higher temperatures (540 K) substantially the same relationships were shown. The effect of solvent-to-coal ratio was also found to be very great. Differential scanning calorimetry gave some low reliability specific heat results and showed indication of a probable heat effect at about 500 K. No indication of exothermic reaction with hydrogen was found.
Date: July 17, 1981
Creator: Droege, J. W.; Venkateswar, R. & Chauhan, S. P.
Object Type: Report
System: The UNT Digital Library
Texas Register, Volume 6, Number 54, Pages 2447-2558, July 17, 1981 (open access)

Texas Register, Volume 6, Number 54, Pages 2447-2558, July 17, 1981

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: July 17, 1981
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Open loop pneumatic control of a Lysholm engine or turbine exhaust pressure (open access)

Open loop pneumatic control of a Lysholm engine or turbine exhaust pressure

A Lysholm engine, or helical screw expander, is currently being evaluated at the University of California, Berkeley for staging with a conventional turbine in geothermal energy conversion. A pneumatic closed loop, proportional-integral control system was implemented to control the Lysholm engine's exhaust pressure for performance testing of the engine at constant inlet/outlet pressure ratios. The control system will also be used to control the exhaust pressure of the conventional turbine during future testing of the staged Lysholm-turbine system. Analytical modeling of the control system was performed and successful tuning was achieved by applying Ziegler-Nichol's tuning method. Stable control and quick response, of approximately 1 minute, was demonstrated for load and set point changes in desired exhaust pressures.
Date: July 17, 1981
Creator: Plonski, B.A.
Object Type: Report
System: The UNT Digital Library
Method and apparatus for measuring flow velocity using matched filters (open access)

Method and apparatus for measuring flow velocity using matched filters

An apparatus and method for measuring the flow velocities of individual phase flow components of a multiphase flow is disclosed. Signals arising from flow noise disturbance are extracted from the flow, at upstream and downstream locations. The signals are processed through pairs of matched filters which are matched to the flow disturbance frequency characteristics of the phase flow component to be measured. The processed signals are then cross-correlated to determine the transit delay time of the phase flow component between sensing positions.
Date: July 17, 1981
Creator: Raptis, A. C.
Object Type: Patent
System: The UNT Digital Library