408 research outputs found

    Titan's spectrum and atmospheric composition

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    Spectroscopic evidence shows that hydrogen atoms are major constituents of Titan's atmosphere. Anomalous enhancement of the methane absorption band is attributed to isotopic shifts arising from methane photolysis. Anomalous ultraviolet absorption features suggest high altitude dust and an elevated cloud layer overlaying most of the methane in the atmosphere

    The jovian environment

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    Jovian atmosphere and environment - composition, structure, and photometric properties of atmosphere, period of rotation, magnetic field, and Jovian radiofrequency spectru

    Rehabilitation in pediatric nursing education

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    Thesis (M.S.)--Boston Universit

    Interview with Barbara Trafton by Andrea L’Hommedieu

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    Biographical NoteBarbara (McKnight) Trafton was born May 22, 1949, in Rumford, Maine. She was graduated from Wellesley College with the class of 1971, then attended the University of Southern Maine and earned an M.Ed., and later went to Northeastern for an M.B.A. She has served in the Maine state House and state Senate for two terms and has been a member of the following committees: Joint Committee, Energy Health and Institutional Services in the House; Joint Committees in the Senate: Judiciary and Public Utilities. She served as the Maine Democratic National Committeewoman, was spokesperson for Maine Turnpike widening in 1991, and is on the Board of the Maine Audubon Society, chairman of the Legislative Policy Committee, the Board of Trustees of the Maine Maritime Academy, and the Review Committee for the Department of Environmental Protection (DEP). She served on the Board of the Mitchell Institute for several years. She has been deeply involved in Maine politics for decades, hosting many candidate events and serving as one of four campaign co-chairs in George Mitchell’s 1982 U.S. Senate campaign. SummaryInterview includes discussion of: meeting and first impressions of George Mitchell; 1974 gubernatorial campaign; Marty Engstrom story; 1982 U.S. Senate campaign strategy and four campaign chairs; Edmund Muskie; Dave Emery; convention to elect Maine Democratic Committeeperson; stumping for Chip Bull with Edward Kennedy; lollipop story and Sam Trafton; formation of the Mitchell Institute and allocation of scholarships; benefit of the Mitchell Institute’s study on reaching secondary education; and Mitchell’s emphasis on the value of education

    Far Field Deposition Of Scoured Regolith Resulting From Lunar Landings

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    As a lunar lander approaches a dusty surface, the plume from the descent engine impinges on the ground, entraining loose regolith into a high velocity dust spray. Without the inhibition of a background atmosphere, the entrained regolith can travel many kilometers from the landing site. In this work, we simulate the flow field from the throat of the descent engine nozzle to where the dust grains impact the surface many kilometers away. The near field is either continuum or marginally rarefied and is simulated via a loosely coupled hybrid DSMC - Navier Stokes (DPLR) solver. Regions of two-phase and polydisperse granular flows are solved via DSMC. The far field deposition is obtained by using a staged calculation, where the first stages are in the near field where the flow is quasi-steady and the outer stages are unsteady. A realistic landing trajectory is approximated by a set of discrete hovering altitudes which range from 20m to 3m. The dust and gas motions are fully coupled using an interaction model that conserves mass, momentum, and energy statistically and inelastic collisions between dust particles are also accounted for. Simulations of a 4 engine configuration are also examined, and the erosion rates as well as near field particle fluxes are discussed.Astronom

    Seasonal Variability In The Ionosphere Of Uranus

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    Infrared ground-based observations using IRTF, UKIRT, and Keck II of Uranus have been analyzed as to identify the long-term behavior of the H-3(+) ionosphere. Between 1992 and 2008 there are 11 individual observing runs, each recording emission from the H-3(+) Q branch emission around 4 mu m through the telluric L' atmospheric window. The column-averaged rotational H-3(+) temperature ranges between 715 K in 1992 and 534 K in 2008, with the linear fit to all the run-averaged temperatures decreasing by 8 K year(-1). The temperature follows the fractional illumination curve of the planet, declining from solstice (1985) to equinox (2007). Variations in H-3(+) column density do not appear to be correlated to either solar cycle phase or season. The radiative cooling by H-3(+) is similar to 10 times larger than the ultraviolet solar energy being injected to the atmosphere. Despite the fact that the solar flux alone is incapable of heating the atmosphere to the observed temperatures, the geometry with respect to the Sun remains an important driver in determining the thermospheric temperature. Therefore, the energy source that heats the thermosphere must be linked to solar mechanisms. We suggest that this may be in the form of conductivity created by solar ionization of atmospheric neutrals and/or seasonally dependent magnetospherically driven current systems.STFC PP/E/000983/1, ST/G0022223/1RCUKGemini ObservatoryNational Aeronautics and Space Administration (NASA) NXX08A043G, NNX08AE38AAstronom

    Mutual Event Observations of Io's Sodium Corona

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    We have measured the column density profile of Io's sodium corona using 10 mutual eclipses between the Galilean satellites. This approach circumvents the problem of spatially resolving Io's corona directly from Io's bright continuum in the presence of atmospheric seeing and telescopic scattering. The primary goal is to investigate the spatial and temporal variations of Io's corona. Spectra from the Keck Observatory and McDonald Observatory from 1997 reveal a corona that is only approximately spherically symmetric around Io. Comparing the globally averaged radial sodium column density profile in the corona with profiles measured in 1991 and 1985, we find that there has been no significant variation. However, there appears to be a previously undetected asymmetry: the corona above Io's sub-Jupiter hemisphere is consistently more dense than above the anti-Jupiter hemisphere

    Effects of valent image-based secondary tasks on verbal working memory

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    Two experiments examined if exposure to emotionally valent image-based secondary tasks introduced at different points of a free recall working memory (WM) task impair memory performance. Images from the International Affective Picture System (IAPS) varied in the degree of negative or positive valance (mild, moderate, strong) and were positioned at low, moderate and high WM load points with participants rating them based upon perceived valence. As predicted, and based on previous research and theory, the higher the degree of negative (Experiment 1) and positive (Experiment 2) valence and the higher the WM load when a secondary task was introduced, the greater the impairment to recall. Secondary task images with strong negative valance were more disruptive than negative images with lower valence at moderate and high WM load task points involving encoding and/or rehearsal of primary task words (Experiment 1). This was not the case for secondary tasks involving positive images (Experiment 2), although participant valence ratings for positive IAPS images classified as moderate and strong were in fact very similar. Implications are discussed in relation to research and theory on task interruption and attentional narrowing and literature concerning the effects of emotive stimuli on cognition

    Abundances of ammonia and carbon disulfide in the Jovian stratosphere following the impact of comet Shoemaker‐Levy 9

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95648/1/grl8459.pd

    Pluto's extended atmosphere: An escape model and initial observations

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    We have calculated the rates of production and hydrodynamic outflow of atomic hydrogen resulting from the photodissociation of methane in the upper atmosphere of Pluto. Under the present near-perihelion conditions this yields an extended cloud of H around Pluto which is likely to be the most easily observable signature of Pluto's extended atmosphere, and thereby provide information on the extent, escape rate, and composition of Pluto's upper atmosphere. We have also performed initial observations with the IUE attempting to detect the H Ly [alpha] emission from the extended H cloud, which we use to derive upper limits to the cloud properties as a function of the cloud extent.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30226/1/0000618.pd
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