Static Footprint Local Forces, Areas, and Aspect Ratios for Three Type 7 Aircraft Tires

The National Tire Modeling Program (NTMP) is a joint NASA/industry effort to improve the understanding of tire mechanics and develop accurate analytical design tools. This effort includes fundamental analytical and experimental research on the structural mechanics of tires. Footprint local forces, areas, and aspect ratios were measured. Local footprint forces in the vertical, lateral, and drag directions were measured with a special footprint force transducer. Measurements of the local forces in the footprint were obtained by positioning the transducer at specified locations within the footprint and externally loading the tires. Three tires were tested: (1) one representative of those used on the main landing gear of B-737 and DC-9 commercial transport airplanes, (2) a nose landing gear tire for the Space Shuttle Orbiter, and (3) a main landing gear tire for the Space Shuttle Orbiter. Data obtained for various inflation pressures and vertical loads are presented for two aircraft tires. The results are presented in graphical and tabulated forms

F-106B airplane active control landing gear drop test performance

Aircraft dynamic loads and vibrations resulting from landing impact and from runway and taxiway unevenness are recognized as significant factors in causing fatigue damage, dynamic stress on the airframe, crew and passenger discomfort, and reduction of the pilot's ability to control the aircraft during ground operations. One potential method for improving operational characteristics of aircraft on the ground is the application of active control technology to the landing gears to reduce ground loads applied to the airframe. An experimental investigation was conducted on series-hydraulic active control nose gear. The experiments involved testing the gear in both passive and active control modes. Results of this investigation show that a series-hydraulic active control gear is feasible and that such a gear is effective in reducing the loads transmitted by the gear to the airframe during ground operations

Speckle Camera Observations for the NASA Kepler Mission Follow-up Program

We present the first results from a speckle imaging survey of stars classified as candidate exoplanet host stars discovered by the Kepler mission. We use speckle imaging to search for faint companions or closely aligned background stars that could contribute flux to the Kepler light curves of their brighter neighbors. Background stars are expected to contribute significantly to the pool of false positive candidate transiting exoplanets discovered by the Kepler mission, especially in the case that the faint neighbors are eclipsing binary stars. Here, we describe our Kepler follow-up observing program, the speckle imaging camera used, our data reduction, and astrometric and photometric performance. Kepler stars range from R = 8 to 16 and our observations attempt to provide background non-detection limits 5-6 mag fainter and binary separations of ~0.05-2.0 arcsec. We present data describing the relative brightness, separation, and position angles for secondary sources, as well as relative plate limits for non-detection of faint nearby stars around each of 156 target stars. Faint neighbors were found near 10 of the stars

Multi-spectral window radiance observations of Cirrus from satellite and aircraft, November 2, 1986 Project FIRE

High resolution infrared radiance spectra achieved from the NASA ER2 airborne HIS experiment are used to analyze the spectral emissivity properties of cirrus clouds within the 8 to 12 micron atmospheric window region. Observations show that the cirrus emissivity generally decreases with increasing wavenumber (i.e., decreasing wavelength) within this band. A very abrupt decrease in emissivity (increase in brightness temperature) exists between 930/cm (10.8 microns) and 1000/cm (10.0 microns), the magnitude of the change being associated with the cirrus optical thickness as observed by lidar. The HIS observations are consistent with theoretical calculations of the spectral absorption coefficient for ice. The HIS observations imply that cirrus clouds can be detected unambiguously from the difference in brightness temperatures observed within the 8.2 and 11.0 micron window regions of the HIRS sounding radiometer flying on the operational NOAA satellites. This ability is demonstrated using simultaneous 25 km resolution HIRS observations and 1 km resolution AVHRR imagery achieved from the NOAA-9 satellite. Finally, the cirrus cloud location estimates combined with the 6.7 micron channel moisture imagery portray the boundaries of the ice/vapor phase of the upper troposphere moisture. This phase distinction is crucial for infrared radiative transfer considerations for weather and climate models, since upper tropospheric water vapor has little effect on the Earth's outgoing radiation whereas cirrus clouds have a very large attenuating effect

Perceptions of Active Learning between Faculty and Undergraduates: Differing Views among Departments

There have been numerous calls recently to increase the use of active learning in university science, technology, engineering, and math (STEM) classrooms to more actively engage students and enhance student learning. However, few studies have investigated faculty and student perceptions regarding the effectiveness of active learning or the barriers to its implementation. Previous work surveying a single class in a single department has suggested that faculty and students have different perceptions of the effectiveness of active learning strategies and the barriers faculty face when implementing these teaching strategies. We expand on these previous findings by surveying a larger and more diverse sample of students and faculty in a college consisting of five departments. We find that students and faculty agree that active learning techniques are useful, effective, and should be implemented more widely, but disagree on the percentage of class time currently devoted to active learning. When we parsed the data by department, more nuanced perceptions became apparent. The perceived barriers to implementing teaching reform differed in importance by department and in some departments relatively few faculty had observed or used active learning. Our findings suggest that advocates of teaching reform must recognize that not all departments or institutions face the same barriers to implementing curricular changes

Roles matter: Graduate student perceptions of active learning in the STEM courses they take and those they teach

Despite many calls to reform undergraduate science, technology, engineering, and math (STEM) education to incorporate active learning into classes, there has been little attention paid to graduate level classrooms or courses taught by graduate students. Here, we set out to understand if and how STEM graduate students’ perceptions of active learning change in the classes they take versus those they teach. We found that graduate students had taken relatively few graduate level classes using active learning and they felt that more time should be devoted to active learning in the courses they were taking. Teaching assistants felt that they were devoting the right amount of class time to active learning in the classes they taught. Graduate students also felt that they were using teaching methods in the classes they taught that were different from those they thought should be used when teaching undergraduates and were different from how they preferred to learn when taking classes

Transformational Leadership in Higher Education Programs

The current mixed-method study investigates transformational leadership qualities through higher education doctoral programs in the Commonwealth of Virginia. This study relies on three data points: interviews with graduate program directors of higher education doctoral programs (whether PhD or EdD), a program evaluation of programs, and Multifactor Leadership Questionnaire (MLQ-5x™) survey results from students within said programs. Data were collected from the five public universities that offer higher education doctoral programs within the Commonwealth of Virginia. Students completed a self-rating using the Multifactor Leadership Questionnaire (MLQ-5x™) and then were peer-rated by colleagues to strengthen the validity of the study. Additionally, themes surrounding the structures of these doctoral programs were collected. As researchers of higher education and leadership studies cite transformational leadership as a high competency for college and university presidents, coupled with a looming shortage of college and university presidents on the horizon, measuring the programs that train these potential future leaders is warranted

Observations of Binary Stars with the Differential Speckle Survey Instrument. V. Toward an Empirical Metal-Poor Mass-Luminosity Relation

In an effort to better understand the details of the stellar structure and evolution of metal poor stars, the Gemini North telescope was used on two occasions to take speckle imaging data of a sample of known spectroscopic binary stars and other nearby stars in order to search for and resolve close companions. The observations were obtained using the Differential Speckle Survey Instrument, which takes data in two filters simultaneously. The results presented here are of 90 observations of 23 systems in which one or more companions was detected, and 6 stars where no companion was detected to the limit of the camera capabilities at Gemini. In the case of the binary and multiple stars, these results are then further analyzed to make first orbit determinations in five cases, and orbit refinements in four other cases. Mass information is derived, and since the systems span a range in metallicity, a study is presented that compares our results with the expected trend in total mass as derived from the most recent Yale isochrones as a function of metal abundance. These data suggest that metal-poor main-sequence stars are less massive at a given color than their solar-metallicity analogues in a manner consistent with that predicted from the theory