Design and development of a solar array drive

The design and development of a dry lubricated direct drive solar array pointing mechanism is discussed for use on the Orbital Test Satellite (OTS), MAROTS, European Communication Satellite (ECS), and others. Results of life testing the original prototype and the OTS mechanism are presented together with an appraisal of expected future development

College Football Games and Crime

There is a great deal of anecdotal evidence that college football games can lead to aggressive and destructive behavior by fans. However, to date, no empirical study has attempted to document the magnitude of this phenomenon. We match daily data on offenses from the NIBRS to 26 Division I-A college football programs in order to estimate the relationship between college football games and crime. Our results suggest that the host community registers sharp increases in assaults, vandalism, arrests for disorderly conduct, and arrests for alcohol-related offenses on game days. Upsets are associated with the largest increases in the number of expected offenses. These estimates are discussed in the context of psychological theories of fan aggression

Numerical simulations of the seasonal/latitudinal variations of atomic oxygen and nitric oxide in the lower thermosphere and mesosphere

A 2-Dimensional zonally-averaged thermospheric model and the global University College London (UCL) thermospheric model have been used to investigate the seasonal, solar activity and geomagnetic variation of atomic oxygen and nitric oxide. The 2-dimensional model includes detailed oxygen and nitrogen chemistry, with appropriate completion of the energy equation, by adding the thermal infrared cooling by O and NO. This solution includes solar and auroral production of odd nitrogen compounds and metastable species. This model has been used for three investigations; firstly, to study the interactions between atmospheric dynamics and minor species transport and density; secondly, to examine the seasonal variations of atomic oxygen and nitric oxide within the upper mesosphere and thermosphere and their response to solar and geomagnetic activity variations; thirdly, to study the factor of 7 to 8 peak nitric oxide density increase as solar F sub 10.7 cm flux increases from 70 to 240 reported from the Solar Mesospheric Explorer. Auroral production of NO is shown to be the dominant source at high latitudes, generating peak NO densities a factor of 10 greater than typical number densities at low latitudes. At low latitudes, the predicted variation of the peak NO density, near 110 km, with the solar F sub 10.7 cm flux is rather smaller than is observed. This is most likely due to an overestimate of the soft X-ray flux at low solar activity, for times of extremely low support number, as occurred in June 1986. As observed on pressure levels, the variation of O density is small. The global circulation during solstice and periods of elevated geomagnetic activity causes depletion of O in regions of upwelling, and enhancements in regions of downwelling

Calculation of wind-driven surface currents in the North Atlantic Ocean

Calculations to simulate the wind driven near surface currents of the North Atlantic Ocean are described. The primitive equations were integrated on a finite difference grid with a horizontal resolution of 2.5 deg in longitude and latitude. The model ocean was homogeneous with a uniform depth of 100 m and with five levels in the vertical direction. A form of the rigid-lid approximation was applied. Generally, the computed surface current patterns agreed with observed currents. The development of a subsurface equatorial countercurrent was observed

Main and interactive effects of attribution dimensions on efficacy expectations in sport.

types: Journal ArticleCopyright © 2007 Taylor & Francis. This is an Author's Accepted Manuscript of an article published in Journal of Sports Sciences, 2007, Vol. 25, Issue 4, pp. 473 - 480, available online at: http://www.tandfonline.com/doi/abs/10.1080/02640410600703063#.VNne651FDcsIn this study, I examined the main and interactive effects of attribution dimensions on efficacy expectations in sport. A sample of 162 athletes (102 males, 60 females) aged 20.9 years (s = 3.4) from various sports were recruited. The participants, who were of club to international standard, completed the Causal Dimension Scale II (McAuley et al., 1992) in relation to their most recent performance. They then completed a 7-item measure of efficacy expectations in relation to their upcoming performance. The key predictors of efficacy expectations were stability and personal control, but their function differed after more or less successful performances. After more successful performances, attributions to stability and personal control were associated with main effects upon efficacy expectations, in a positive direction; after less successful performances, attributions to stability and personal control were associated with an interactive effect upon efficacy expectations. The form of this effect was such that the participants were more likely to have high efficacy expectations only when they viewed the cause of their performances as both personally controllable and stable

The Hydrozoan Cladonema in California: A Possible Introduction from East Asia

A hydrozoan of the genus Cladonema, new to the American west coast, is described from specimens taken from a display tank on the Berkeley campus of the University of California. Observations of its life history revealed it to be synonymous with Cladonema uchidai Hirai, 1958, known and described from northern Japan, although its distribution is probably much wider and includes coastal China and the USSR. The species is presumed to be present in San Francisco Bay, a point of introduction for many exotic species, although it is not yet known from the field

Kinematics of the Broad Line Region in M81

A new model is presented which explains the origin of the broad emission lines observed in the LINER/Seyfert nucleus of M81 in terms of a steady state spherically symmetric inflow, amounting to 1 x 10^-5 Msun/yr, which is sufficient to explain the luminosity of the AGN. The emitting volume has an outer radius of ~1 pc, making it the largest broad line region yet to be measured, and it contains a total mass of ~ 5 x 10^-2 Msun of dense, ~ 10^8 cm^-3, ionized gas, leading to a very low filling factor of ~ 5 x 10^-9. The fact that the BLR in M81 is so large may explain why the AGN is unable to sustain the ionization seen there. Thus, the AGN in M81 is not simply a scaled down quasar.Comment: Accepted for Publication in ApJ 7/21/0

Self-consistent modelling of the polar thermosphere and ionosphere to magnetospheric convection and precipitation (invited review)

It has recently been demonstrated that the dramatic effects of plasma precipitation and convection on the composition and dynamics of the polar thermosphere and ionosphere include a number of strong interactive, or feedback, processes. To aid the evaluation of these feedback processes, a joint three dimensional time dependent global model of the Earth's thermosphere and ionosphere was developed in a collaboration between University College London and Sheffield University. This model includes self consistent coupling between the thermosphere and the ionosphere in the polar regions. Some of the major features in the polar ionosphere, which the initial simulations indicate are due to the strong coupling of ions and neutrals in the presence of strong electric fields and energetic electron precipitation are reviewed. The model is also able to simulate seasonal and Universal time variations in the polar thermosphere and ionospheric regions which are due to the variations of solar photoionization in specific geomagnetic regions such as the cusp and polar cap

Adaptation of a general circulation model to ocean dynamics

A primitive-variable general circulation model of the ocean was formulated in which fast external gravity waves are suppressed with rigid-lid surface constraint pressires which also provide a means for simulating the effects of large-scale free-surface topography. The surface pressure method is simpler to apply than the conventional stream function models, and the resulting model can be applied to both global ocean and limited region situations. Strengths and weaknesses of the model are also presented