Measurement of Noise Produced by a Plasma Contactor Operating in Ground Based Facilities

Methods to measure electric field fluctuations accurately in a plasma with an active monopole antenna are described. It is shown that the conductive surfaces of the antenna must be adequately isolated from the ambient plasma and that the monopole must be sufficiently short to avoid antenna amplifier saturation. Experimental results illustrate that the noise produced by plasma contactor operation and sensed by the antenna is due to plasma phenomena and is not induced by laboratory power supplies. A good correlation is shown between the current fluctuations in the contactor electrical circuit and the noise detected by the antenna. A large body of experimental data support the conclusion that the majority of noise sensed by the antenna at frequencies less than 1 MHz is due to current fluctuations (electrostatic waves) in the plasma adjacent to the antenna and not to electromagnetic wave radiation. Caution is suggested when comparing antenna noise measurements to conventional specifications for radiated emissions

The Effects of Sport Participation on Student-Athletes’ and Non-Athlete Students’ Social Life and Identity

This study examined perceived athletic identity, sport commitment, and the effect of sport participation to identify the impact of athletic participation on college students. This study surveyed 163 student-athletes (59%) and 112 non-athlete students (41%) from a National Collegiate Athletic Association Division-I affiliated institution (males = 172, 62.5%; females = 103, 37.5%). The survey questionnaire was developed and modified from four well-established instruments, the Athletic Identity Measurement Scale, the Sport Commitment Model, the Life Roles Inventory-Values Scales, and Athletic Involvement on the Social Life. The data collection process was initiated and completed in the 2008 spring semester. Seven sub-factors: Personal Role, Importance of Sport, Personal Attributes, Expectation of Others, Core Benefits, Social Relationship and Special Behaviors, were identified through a series of factor analyses. The participants placed their athletic role highly and moderately agreed with the researchers’ proposed core benefits of athletic participation. Overall, the findings supported past research in regards to gender and year in college difference, influence in perceived athletic identity due to sport specificity, and benefits of sport involvement. Variation in participants’ responses based on different demographic characteristics, suggestions for improving current supportive programs, and direction for future studies are further discussed

Carbon Nanotube Coatings as Used in Strain Sensors for Composite Tanks

The next generation of cryogenic fuel tanks, crew habitats and other components for future spacecraft will focus on the usc of lightweight carbon fiber composite materials. A critical issue in the design and optimization of such tanks and structures will bc in structural health monitoring, however, current strain sensors have limitations. In this study, a novel carbon nanotube thin film was applied to carbon fiber composites for structural monitoring. Applying a load using a 3-point bend test to simulate bowing of a tank wall, induced significant increases in the film's electrical resistance at small deflections. Upon release of the load, the resistance returned to its approximate start value and was reproducible over multiple tests. The results show that a carbon nanotube thin film has great potential for the health monitoring of composite structures

Perceptions of secondary principals in Texas concerning leadership skills attained through membership and participation in the FFA

Abstract The primary purpose of this study was to determine Texas secondary principals' perceptions of leadership skills attained through membership and participation in the FFA program. The target population consisted of Texas secondary principals located at schools with an agricultural science program and chartered FFA chapter. A stratified sample of 288 principals was selected. A questionnaire was developed by the researcher concerning leadership skills and the FFA program. After pilot testing of the questionnaire, it was mailed to the participants of the study to complete. Overall, secondary principals in Texas agreed that membership and participation in the FFA program offers students the opportunity to develop leadership skills. Principals surveyed also agreed that participation in the FFA program helps students to generate goals, establish priorities, develop responsibility, enhance social skills, improve problem solving abilities, listen to others and develop honesty and integrity. The conclusions drawn from this study have opened the door for further research. Now that Texas secondary principals' perceptions of the attainment of leadership skills by students through membership and participation in the FFA program have been gathered and analyzed, their perceptions regarding other important issues such as curriculum, course offerings and graduation requirements should be collected and analyzed. The results from this study and future studies can be used to build and create relationships between agricultural science teachers and secondary principals allowing them to work together more efficiently to the benefit of the student