Ray tracing of Jovian low frequency radiation

The radio emission from Jupiter in the decametric range (2 to 40 MHz) has been studied for three decades. It is known that this emission is correlated with particular longitude regions on the planet and with the position of the satellite Io. The Planetary Radio Astronomy experiment on the Voyager 1 and 2 spacecraft observed this emission, obtaining valuable new information. The objectives of this study are as follows: (1) calculate raypaths for decametric wavelength radiation in Jupiter's magnetosphere; (2) compare the model-dependent raypaths with the Voyager observations; and (3) deduce characteristics of the source regions and the influence of propagation effects

Research reports: 1991 NASA/ASEE Summer Faculty Fellowship Program

The basic objectives of the programs, which are in the 28th year of operation nationally, are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of the participants' institutions; and (4) to contribute to the research objectives of the NASA Centers. The faculty fellows spent 10 weeks at MSFC engaged in a research project compatible with their interests and background and worked in collaboration with a NASA/MSFC colleague. This is a compilation of their research reports for summer 1991

Research reports: 1990 NASA/ASEE Summer Faculty Fellowship Program

Reports on the research projects performed under the NASA/ASEE Summer Faculty Fellowship Program are presented. The program was conducted by The University of Alabama and MSFC during the period from June 4, 1990 through August 10, 1990. Some of the topics covered include: (1) Space Shuttles; (2) Space Station Freedom; (3) information systems; (4) materials and processes; (4) Space Shuttle main engine; (5) aerospace sciences; (6) mathematical models; (7) mission operations; (8) systems analysis and integration; (9) systems control; (10) structures and dynamics; (11) aerospace safety; and (12) remote sensin

1992 NASA/ASEE Summer Faculty Fellowship Program

For the 28th consecutive year, a NASA/ASEE Summer Faculty Fellowship Program was conducted at the Marshall Space Flight Center (MSFC). The program was conducted by the University of Alabama and MSFC during the period June 1, 1992 through August 7, 1992. Operated under the auspices of the American Society for Engineering Education, the MSFC program, was well as those at other centers, was sponsored by the Office of Educational Affairs, NASA Headquarters, Washington, DC. The basic objectives of the programs, which are the 29th year of operation nationally, are (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate and exchange ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of the participants' institutions; and (4) to contribute to the research objectives of the NASA centers

Modeling and investigative studies of Jovian low frequency emissions

Jovian decametric (DAM) and hectometric (HOM) emissions were first observed over the entire spectrum by the Voyager 1 and 2 flybys of the planet. They display unusual arc-like structures on frequency-versus-time spectrograms. Software for the modeling of the Jovian plasma and magnetic field environment was performed. In addition, an extensive library of programs was developed for the retrieval of Voyager Planetary Radio Astronomy (PRA) data in both the high and low frequency bands from new noise-free, recalibrated data tapes. This software allows the option of retrieving data sorted with respect to particular sub-Io longitudes. This has proven to be invaluable in the analyses of the data. Graphics routines were also developed to display the data on color spectrograms

Acoustical properties in inhaling singing : a case-study

A highly experienced versatile female professional singer displaying no apparent vocal complaint, developed inhaling singing, an innovative approach to reverse phonation. Although there are some reports in literature that describe the characteristics of ingressive phonation and sounds, to the best of our knowledge, no reports on actual inhaling singing are available in literature. This paper reports a case study on the acoustical analysis of inhaling singing, comparing this innovative technique with traditional exhaling singing. As this is rather undiscovered territory, we have decided to address several questions: is it possible to match the same pitches using inhaling singing compared to exhaling singing? Is the harmonic structure and energy distribution similar? Is it possible to maintain the same phonation duration in both techniques? Are there differences in volume and tessitura (vocal range)? This paper, reporting on the experience of one individual, demonstrates that a tessitura can be mastered in inhaling singing. Spectral analysis reveals a similar frequency distribution in both conditions. However, in inhaling singing the energy of the harmonics is significantly lower for the first 3 overtones, while the maximum phonation time is larger, than in exhaling singing. The singer reports that less effort is required for inhaling singing in the high register. As such, inhaling singing offers new possibilities for vocal performance

Research Reports: 1989 NASA/ASEE Summer Faculty Fellowship Program

For the twenty-fifth consecutive year, a NASA/ASEE Summer Faculty Fellowship Program was conducted at the Marshall Space Flight Center (MSFC). The basic objectives of the programs are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of the participants' institutions; and (4) to contribute to the research objectives of the NASA Centers. The Faculty Fellows spent ten weeks at MSFC engaged in a research project compatible with their interests and background and worked in collaboration with a NASA/MSFC colleague

The Ultrasonic Piezo Drive an Innovative Solution for High-Accuracy Positioning

Piezo-electric motors have been successfully developed for various applications like autofocus drives in camera lenses and handling equipment for semiconductor production. Their high speed and accurate positioning capability, combined with a favourable holding torque in unpowered condition, make piezo motors also very attractive for actuation purposes in spacecraft mechanisms. However, so far only a few studies have been reported considering their suitability for actual use in space. Piezo motors use a combination of piezo-electric and friction forces to generate a progressive motion of an output element. Such output motion can be a linear translation or a rotation in accordance with the actuation requirements of a particular application. Since piezo motors rely on friction at a controlled mechanical contact interface, the related tribology in vacuum and under varying temperature conditions is of critical importance for the function and operational lifetime of such motors. The paper introduces a new concept of a versatile piezo motor driven at ultrasonic frequency, and it elaborates on a number of space-related issues like the compatibility with the relevant mechanical and thermal environment. Furthermore, the possible implementation in different space mechanisms is discussed, with specific focus on miniaturised equipment as needed for small satellites

Research reports: 1994 NASA/ASEE Summer Faculty Fellowship Program

For the 30th consecutive year, a NASA/ASEE Summer Faculty Fellowship Program was conducted at the Marshall Space Flight Center (MSFC). The basic objectives of the programs, which are in the 31st year of operation nationally, are (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants' institutions; and (4) to contribute to the research objectives of the NASA centers. The Faculty Fellows spent 10 weeks at MSFC engaged in a research project compatible with their interests and background and worked in collaboration with a NASA/MSFC colleague. This document is a compilation of Fellows' reports on their research during the summer of 1994

Synchronisation sensorimotrice et comportements non verbaux dans la maladie d’Alzheimer : l’influence du contexte social et musical = Sensorimotor synchronization and non-verbal behaviors in Alzheimer's disease : the influence of social and musical context

Cette étude vise à examiner les facteurs qui influencent l’engagement socio-émotionnel et moteur et la synchronisation sensorimotrice (SSM) pendant une activité musicale chez des patients présentant une maladie d’Alzheimer. La tâche consistait à taper avec un rythme métronomique ou musical devant une musicienne réalisant la même tâche, qui était présente physiquement ou virtuellement sur un écran. Selon nos résultats, les patients produisaient plus de mouvements rythmiques en réponse à la musique qu’au métronome. Cependant, la SSM était meilleure avec le métronome qu’avec la musique et en présence virtuelle plutôt que réelle de la musicienne. Ces données confirment l’importance du contexte musical et des interactions sociales sur l’engagement moteur et la synchronisation. En revanche, aucun effet sur l’engagement socio-émotionnel n’a été observé. En évaluant en parallèle la SSM, les comportements moteurs spontanés et socio-émotionnels à partir de mesures quantitatives, cette étude permet de valider une approche multimodale d’évaluation de l’engagement des patients dans une tâche musicale. Les perspectives d’applications prometteuses de ce travail mettent à la disposition des cliniciens et des chercheurs une méthodologie rigoureuse pour comprendre les facteurs qui sont à l’origine des bénéfices thérapeutiques des activités musicales sur le comportement et le bien-être des patients et de leurs aidants.Considering the limited efficacy of pharmacological treatments, the use of musical interventions as non-drug treatment for patients with Alzheimer's disease are strongly recommended. Musical interventions seem to improve the socio-emotional and cognitive functioning of these patients, with benefits increasing when patients are engaged at the motor level. Objective. Our study evaluates the factors that may influence patients' socio-emotional and motor engagement during musical activities, and measures their sensorimotor synchronization (SMS) abilities. Methods. Each participant was asked to tap with a metronomic or a musical rhythm, in the presence of a musician who performed the task with them. The presence of the musician was real (live condition) or virtual (video condition). Two tempi were tested: a slow tempo (inter-onset interval of 800 ms) and a fast tempo (inter-onset interval of 667 ms). Results. Patients spontaneously produced more rhythmic movements in response to the music than to the metronome. However, the consistency and accuracy of sensorimotor synchronization were better with the metronome than with the music, and also better in video than in live condition. These effects were modulated by the tempo of the auditory sequences. Conclusion. These results confirm the importance of the musical context and social interactions on these different performances. By evaluating in parallel the hand sensorimotor synchronization, spontaneous motor and socio-emotional behaviors with quantitative and controlled measurements, this study validates a multimodal approach to evaluate the patients' engagement in a musical task. These initial results open up promising application prospects while providing clinicians and researchers a rigorous methodology for understanding the factors that are at the origin of the therapeutic benefits of musical activities on the behavior and well-being of patients and their caregivers