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Electron loss rates from the outer radiation belt caused by the filling of the outer plasmasphere: The calm before the storm
Measurements from seven spacecraft in geosynchronous orbit are analyzed to determine the decay rate of the number density of the outer electron radiation belt prior to the onset of high-speed-stream-driven geomagnetic storms. Superposed-data analysis is used with a collection of 124 storms. When there is a calm before the storm, the electron number density decays exponentially before the storm with a 3.4-day e-folding time: beginning about 4 days before storm onset, the density decreases from ∼4 × 10−4 cm−3 to ∼1 × 10−4 cm−3. When there is not a calm before the storm, the number density decay is very small. The decay in the number density of radiation belt electrons is believed to be caused by pitch angle scattering of electrons into the atmospheric loss cone as the outer plasmasphere fills during the calms. This is confirmed by separately measuring the density decay rate for times when the outer plasmasphere is present or absent. While the radiation belt electron density decreases, the temperature of the electron radiation belt holds approximately constant, indicating that the electron precipitation occurs equally at all energies. Along with the number density decay, the pressure of the outer electron radiation belt decays, and the specific entropy increases. From the measured decay rates, the electron flux to the atmosphere is calculated, and that flux is 3 orders of magnitude less than thermal fluxes in the magnetosphere, indicating that the radiation belt pitch angle scattering is 3 orders weaker than strong diffusion. Energy fluxes into the atmosphere are calculated and found to be insufficient to produce visible airglow
Millenial-Scale Climatic Oscillations in New Zealand During the Last Glacial Cycle; PEP III Transect
Millennial-Scale Climatic Oscillations in New Zealand During the Last Glacial Cycle: PEP III Transect Paleoclimate records from Greenland ice cores and North Atlantic sediments indicate that the glacial climate over the North Atlantic basin was punctuated with large and frequent abrupt climatic changes (Dansgaard-Oeschger and Henrich events). Because the events first appeared to have been regionally restricted, most explanations have invoked regional forcing mechanisms. But quite a different perspective would emerge if these events were shown to be of this global-scale. SGER award supports a reconnaissance study of the glacial and vegetative paleoclimate record of the massive morainal deposits of the Southern Alps of New Zealand This will establish the paleoclimate potential of this record to contribute to our understanding of interhemispheric climatic linkages and forcing mechanisms for the last glacial cycle
Disaffected/Difficult Students Within Design Education: Some Possible Considerations
All teachers have to handle 'difficult' students as a normal part of their teaching load. Two general approaches tend to be adopted in schools: the establishment of withdrawal groups or absorption within mixed ability groups. Whichever technique is used the problems caused by these students are out of all proportion to their numbers and are a major source of both stress for staff and reduced contact with other students, the net effect is to lower the quality of the learning experience. The focus of this article is on the withdrawal technique, though some points will be of interest within mixed ability.The term 'difficult' students does, of course, cover a wide range of specific difficulties and forms of behaviour and many inexperienced teachers make the mistake of attempting to work with them in a similar manner. Having said this and so emphasised the need for consideration of these students as individuals, there are a number of strategies which are worth careful consideration when teaching such students. The factors discussed below are based both upon my own experience conducting research in design departments and those of other practitioners in the field. In dealing with those factors I feel to be most relevant I have identified four broad areas: 1. The identification of students requiring particular help, and selection, if a withdrawal system is to operate.2. Facilities needed when operating in a design faculty. 3. Relationships.4. Work schemes and resources
The Origin of a Polar Ice Sheet in East Antarctica
This award supports a study to determine the sequence and chronology of events that led to the development of the Antarctic ice sheet. A continental-scale ice sheet probably first developed in East Antarctica close to the Eocene-Oligocene boundary under temperate climatic conditions. The purpose of this project is to determine, from landscape analysis (with a numerical chronology), when (and why) these early temperate conditions gave way to a polar environment in Antarctica. From previous field work and recent photographic analysis, an extensive relict landscape (older than 17 million years) with landforms and erosional features characteristic of temperate glaciation has been delineated. This relict landscape has been called the Sessrumnir erosion surface and it extends over three degrees of latitude and covers almost 10,000 km2 in three fault blocks of the Transantarctic Mountains (Convoy, Dry Valleys, Royal Society). It is on this relict land surface that data will be collected which record Middle and Early Miocene glacial history and paleoclimate. The results should allow an identification of the transition from temperate to polar conditions. This work will involve landscape analysis, stratigraphy of glacial deposits, and Argon-40/Argon-39 dating of volcanic ashfalls. Denudation rates will come from fission-track analyses and from exposure-age analyses of bedrock surfaces and erratic boulders. The overall results will elucidate the origin and stability of the polar Antarctic cryosphere
An Application of Price and Quantity Indexes in the Analysis of Changes in Expenditures on Physician Services
Price and quantity indexes are applied in the analysis of expenditure on physician services in the province of Ontario, Canada, using newly available data files for 1992 and 2004. Price indexes for such services are found to have increased less rapidly than indexes of general inflation and quantity indexes are found to account for the largest share of physician expenditure increases. The quantity indexes imply substantial gains in services per capita, especially for older adults. They imply also an increase in labour productivity for physicians that is somewhat greater than the corresponding increase for the economy at large.physician services; price and quantity indexes
Effective Electrostatic Interactions in Suspensions of Polyelectrolyte Brush-Coated Colloids
Effective electrostatic interactions between colloidal particles, coated with
polyelectrolyte brushes and suspended in an electrolyte solvent, are described
via linear response theory. The inner cores of the macroions are modeled as
hard spheres, the outer brushes as spherical shells of continuously distributed
charge, the microions (counterions and salt ions) as point charges, and the
solvent as a dielectric continuum. The multi-component mixture of macroions and
microions is formally mapped onto an equivalent one-component suspension by
integrating out from the partition function the microion degrees of freedom.
Applying second-order perturbation theory and a random phase approximation,
analytical expressions are derived for the effective pair interaction and a
one-body volume energy, which is a natural by-product of the one-component
reduction. The combination of an inner core and an outer shell, respectively
impenetrable and penetrable to microions, allows the interactions between
macroions to be tuned by varying the core diameter and brush thickness. In the
limiting cases of vanishing core diameter and vanishing shell thickness, the
interactions reduce to those derived previously for star polyelectrolytes and
charged colloids, respectively.Comment: 20 pages, 5 figures, Phys. Rev. E (in press
Projections of the Population and Labour Force to 2046: The Provinces and Territories
This report makes available projections of the population and labour force of each of the provinces and territories of Canada. The projections extend to 2046, and are based on information that is up-to-date at the time of release. The report provides an indication of the capabilities of the MEDS software on which the projections are based.population; labour force; projection
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