Preliminary investigation of high power microwave plasmas for electrothermal thruster use

Results are reported from preliminary tests to evaluate the high power microwave electrothermal thruster (MET) concept, which employs a free-floating plasma discharge maintained by applied CW microwave power to heat a propellant gas flow. Stable plasmas have been created and maintained in helium (He), nitrogen (N2), and hydrogen (H2) as propellants in both the TM(sub 011) and TM(sub 012) modes at discharge pressures from 10 Pa to 69 kPa. Reproducible starting conditions of pressure and power have been documented for all the plasmas. Vortical inflow of the propellant gas was observed to cause the formation of on-axis 'spike' plasmas. The formation and unformation conditions of these plasmas were studied. Operation in the spike plasma condition enables maximum power absorption with minimum wall heating and offers maximum efficiency in heating the propellant gas. In the spike condition, plasmas of the three propellant gases were investigated in an open channel configuration to a maximum applied power level of 11.2 kW (in N2). Microwave power coupling efficiencies of over 90 percent were routinely obtained at absorbed power levels up to 2 kW. Magnetic nozzle effects were investigated with a superconducting solenoid Al magnet applying a high magnetic field to the plasmas in and exiting from the discharge tube

The effect of feeding L-thyroxine to dairy cows upon plasma-bound iodine and fecal thyroxine

This study was made to determine the effect of L-thyroxine dose-level and length of time it is fed to lactating cows upon the amounts of thyroxine equivalents in the blood and feces

Opinion in regard to State of Title of Porciones 71 and 72

From John Closner and Family Collection, contains a title abstract prepared by J.C. Sullivan for John Closer for Porcion 71, Narcisco [Narciso] Cavazos Original Grantee (signed 3 January 1905). Opinion in regard to State of Title of Porciones 71 and 72, 1905-01-03, Container: 39, Box: 1, Folder: 10. University of Texas Rio Grande Valley Special Collections and Archives, Edinburg Campus. https://archives.lib.utrgv.edu/repositories/2/archival_objects/80724https://scholarworks.utrgv.edu/hidalgohist/1012/thumbnail.jp

Suicide Bombings in Operation Iraqi Freedom

Suicide bombing is the act of blowing oneself up in order to kill (destroy) or injure (damage) a target. The target may be military or civilian or both. Typically, the killing or physical destruction of the target is less important than the terror generated by undertaking the act. This ultimately makes suicide bombing a “disruptive firepower” capability (based on Bond-Relationship Targeting) utilized by opposing forces (OPFORs) which lack traditional destructive firepower

Heavy trucks, conspicuity treatment, and the decline of collision risk in darkness

In December 1992, Federal Motor Vehicle Safety Standard (FMVSS) 108, was amended to require conspicuity treatments on all heavy trailers manufactured after December 1, 1993. The standard was later modified and extended to tractors and older trailers such that by June 1, 2009 the entire fleet of tractors and semitrailers on United States roadways would reach full compliance with the regulation. To investigate the effect of the regulation, an analysis was conducted of the change in the odds that a fatal crash occurred in darkness, comparing scenarios in which the conspicuity treatment was likely to be influential to those in which the conspicuity treatment was likely to be irrelevant. From 1987 to 2009, the odds that a fatal collision involving a heavy truck occurred in darkness declined by 58% among the relevant crash scenarios, while little evidence of decline was found among the irrelevant scenarios. Disaggregations of crash scenario types suggest that the largest declines occurred in fatal rear end and angle collisions. A comparative analysis of light vehicles also found declines, although they were smaller and less sensitive to crash type. Similar but weaker trends were observed for nonfatal rear end collisions. The results are consistent with causal mechanisms that suggest that detection failure may be a significant contributor to the risk of striking a tractor-semitrailer in darkness, and that conspicuity treatments have significantly reduced this risk.The University of Michigan Industry Affiliation Program for Human Factors in Transportation Safetyhttp://deepblue.lib.umich.edu/bitstream/2027.42/89938/1/102820.pd

VBIEDs in the Mexican Criminal Insurgency

At least 130,000 people have been killed in the ongoing Mexican “crime war,” and many more have been kidnapped or simply gone missing. Yet despite the significance of these numbers, official reports and news accounts frequently underreport the toll of this war