Kolmogorov-Burgers Model for Star Forming Turbulence

The process of star formation in interstellar molecular clouds is believed to be controlled by driven supersonic magnetohydrodynamic turbulence. We suggest that in the inertial range such turbulence obeys the Kolmogorov law, while in the dissipative range it behaves as Burgers turbulence developing shock singularities. On the base of the She-Leveque analytical model we then predict the velocity power spectrum in the inertial range to be E_k ~ k^{-1.74}. This result reproduces the observational Larson law, ~ l^{0.74...0.76}, [Larson, MNRAS 194 (1981) 809] and agrees well with recent numerical findings by Padoan and Nordlund [astro-ph/0011465]. The application of the model to more general dissipative structures, with higher fractal dimensionality, leads to better agreement with recent observational results.Comment: revised, new material added, 8 page

Influence of maneuverability on helicopter combat effectiveness

A computational procedure employing a stochastic learning method in conjunction with dynamic simulation of helicopter flight and weapon system operation was used to derive helicopter maneuvering strategies. The derived strategies maximize either survival or kill probability and are in the form of a feedback control based upon threat visual or warning system cues. Maneuverability parameters implicit in the strategy development include maximum longitudinal acceleration and deceleration, maximum sustained and transient load factor turn rate at forward speed, and maximum pedal turn rate and lateral acceleration at hover. Results are presented in terms of probability of skill for all combat initial conditions for two threat categories

Bridging the gap? The role of transition advisers in the move from compulsory education

The quality and impartiality of careers advice has been in question for as long as it has been provided, with numerous studies (see Morris, 2004 for a summary of NfER research in this area) pointing to the efficacy of impartial guidance, but also pointing to gaps in provision for particular groups. It is possible to distinguish three areas of educational policy - although this is not exhaustive - which have had a clear effect on young people's experience of advice and guidance over recent years. The first area is in provision of careers advice itself. The second area is the 14-19 learning environment. Linked to this shift in the 14-19 environment is the third area, the impact of market-driven reforms starting with the Education Reform Act in 1988.</p

Assimilating the Martian water cycle

Water ice clouds have been shown to alter the thermal structure of the Martian atmosphere. Here we discuss the assimilation of total column water vapour and dust optical depth data from the Thermal Emission Spectrometer (TES) into the UK/LMD MGCM, and compare the predictions of cloud and temperature in the assimilation with observations

Study of arcuate structural trends in Utah and Nevada using ERTS-1 imagery

There are no author-identified significant results in this report

Mass-energy balance for an S-1C rocket exhaust cloud during static firing

Rocket exhaust cloud mass-energy balance measurements for Saturn S1-C static firin

Producing graphite with desired properties

Isotropic or anisotropic graphite is synthesized with precise control of particle size, distribution, and shape. The isotropic graphites are nearly perfectly isotropic, with thermal expansion coefficients two or three times those of ordinary graphites. The anisotropic graphites approach the anisotropy of pyrolytic graphite