7,898 research outputs found
An introduction to the theory and practice of MOVE progression accords.
MOVE progression accords identify specific vocational progression routes from both further
education and the workplace to and through higher education. This includes the provision of
guaranteed places on higher education programmes of study and other agreed collaborative
activities designed to support and prepare learners for progression to higher education.
MOVE progression accords are designed to promote vocational progression opportunities
and to encourage the engagement of employers in supporting progression to higher level
learning in collaboration with MOVE and its partner institutions in the region. In signing the
accord, partners are also committing to implementing an agreed set of ârequiredâ activities
designed to ensure that the accords are seen as a supported, collaborative process between
the practitioners and the learners involved. There is also a list of optional ârecommendedâ
activities. Our approach is predicated on the belief that this shared professional learning will
help to effect behavioural and culture changes that will underpin the continuing success and
sustainability of the accords
Veterinary Medicine Explorer Post Sponsored by the College of Veterinary Medicine
In the mid-1960s the Boy Scouts of America initiated a new approach in their programming. Until that time the Explorer Scout program was outdoor-oriented and aimed at 14 to 18 year old boys pursuing a more advanced experience than the younger Boy Scouts. Exploring became coeducational in the new concept and units were encouraged to develop as career-oriented or special interest Posts
Analytical sun synchronous low-thrust manoeuvres
Article describes analytical sun synchronous low-thrust manoeuvres
An earth pole-sitter using hybrid propulsion
In this paper we investigate optimal pole-sitter orbits using hybrid solar sail and solar electric propulsion (SEP). A pole-sitter is a spacecraft that is constantly above one of the Earth's poles, by means of a continuous thrust. Optimal orbits, that minimize propellant mass consumption, are found both through a shape-based approach, and solving an optimal control problem, using a direct method based on pseudo-spectral techniques. Both the pure SEP case and the hybrid case are investigated and compared. It is found that the hybrid spacecraft allows consistent savings on propellant mass fraction. Finally, is it shown that for sufficiently long missions (more than 8 years), a hybrid spacecraft, based on mid-term technology, enables a consistent reduction in the launch mass for a given payload, with respect to a pure SEP spacecraft
Lattice Kinetics of Diffusion-Limited Coalescence and Annihilation with Sources
We study the 1D kinetics of diffusion-limited coalescence and annihilation
with back reactions and different kinds of particle input. By considering the
changes in occupation and parity of a given interval, we derive sets of
hierarchical equations from which exact expressions for the lattice coverage
and the particle concentration can be obtained. We compare the mean-field
approximation and the continuum approximation to the exact solutions and we
discuss their regime of validity.Comment: 24 pages and 3 eps figures, Revtex, accepted for publication in J.
Phys.
Using Innovative Technologies for Manufacturing Rocket Engine Hardware
Many of the manufacturing techniques that are currently used for rocket engine component production are traditional methods that have been proven through years of experience and historical precedence. As the United States enters into the next space age where new launch vehicles are being designed and propulsion systems are being improved upon, it is sometimes necessary to adopt innovative techniques for manufacturing hardware. With a heavy emphasis on cost reduction and improvements in manufacturing time, rapid manufacturing techniques such as Direct Metal Laser Sintering (DMLS) are being adopted and evaluated for their use on NASA s Space Launch System (SLS) upper stage engine, J-2X, with hopes of employing this technology on a wide variety of future projects. DMLS has the potential to significantly reduce the processing time and cost of engine hardware, while achieving desirable material properties by using a layered powder metal manufacturing process in order to produce complex part geometries. Marshall Space Flight Center (MSFC) has recently hot-fire tested a J-2X gas generator (GG) discharge duct that was manufactured using DMLS. The duct was inspected and proof tested prior to the hot-fire test. Using a workhorse gas generator (WHGG) test fixture at MSFC's East Test Area, the duct was subjected to extreme J-2X hot gas environments during 7 tests for a total of 537 seconds of hot-fire time. The duct underwent extensive post-test evaluation and showed no signs of degradation. DMLS manufacturing has proven to be a viable option for manufacturing rocket engine hardware, and further development and use of this manufacturing method is recommended
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