Adaptive Guidance: Effects On Self-Regulated Learning In Technology-Based Training

Guidance provides trainees with the information necessary to make effective use of the learner control inherent in technology-based training, but also allows them to retain a sense of control over their learning (Bell & Kozlowski, 2002). One challenge, however, is determining how much learner control, or autonomy, to build into the guidance strategy. We examined the effects of alternative forms of guidance (autonomy supportive vs. controlling) on trainees’ learning and performance, and examined trainees’ cognitive ability and motivation to learn as potential moderators of these effects. Consistent with our hypotheses, trainees receiving adaptive guidance had higher levels of knowledge and performance than trainees in a learner control guidance. Controlling guidance had the most consistent positive impact on the learning outcomes, while autonomy supportive guidance demonstrated utility for more strategic outcomes. In addition, guidance was generally more effective for trainees with higher levels of cognitive ability and autonomy guidance served to enhance the positive effects of motivation to learn on the training outcomes

Ion sputter textured graphite electrode plates

A specially textured surface of pyrolytic graphite exhibits extremely low yields of secondary electrons and reduced numbers of reflected primary electrons after impingement of high energy primary electrons. Electrode plates of this material are used in multistage depressed collectors. An ion flux having an energy between 500 iV and 1000 iV and a current density between 1.0 mA/sq cm and 6.0 mA/sq cm produces surface roughening or texturing which is in the form of needles or spires. Such textured surfaces are especially useful as anode collector plates in high tube devices

Ion sputter textured graphite

A specially textured surface of pyrolytic graphite exhibits extremely low yields of secondary electrons and reduced numbers of reflected primary electrons after impingement of high energy primary electrons. An ion flux having an energy between 500 eV and 1000 eV and a current density between 1.0 mA/sq cm and 6.0 mA/sq cm produces surface roughening or texturing which is in the form of needles or spines. Such textured surfaces are especially useful as anode collector plates in high efficiency electron tube devices

Propagation of the phase of solar modulation

The phase of the 11 year galactic cosmic ray variation, due to a varying rate of emission of long lived propagating regions of enhanced scattering, travels faster than the scattering regions themselves. The radial speed of the 11 year phase in the quasi-steady, force field approximation is exactly twice the speed of the individual, episodic decreases. A time dependent, numerical solution for 1 GeV protons at 1 and 30 Au gives a phase speed which is 1.85 times the propagation speed of the individual decreases

Scaling anisotropy of the power in parallel and perpendicular components of the solar wind magnetic field

Power spectra of the components of the magnetic field parallel (Pzz) and perpendicular (Pzz+Pyy) to the local mean magnetic field direction were determined by wavelet methods from Ulysses’ MAG instrument data during eighteen 10-day segments of its first North Polar pass at high latitude at solar minimum in 1995. The power depends on frequency f and the angle θ between the solar wind direction and the local mean field, and with distance from the Sun. This data includes the solar wind whose total power (Pxx + Pyy + Pzz) in magnetic fluctuations we previously reported depends on f and the angle θ nearly as predicted by the GS95 critical balance model of strong incompressible MHD turbulence. Results at much wider range of frequencies during six evenly-spaced 10-day periods are presented here to illustrate the variability and evolution with distance from the Sun. Here we investigate the aniso tropic scaling of Pzz(f,θ) in particular because it is a reduced form of the Poloidal (pseudo-Alfvenic) component of the (incompressible) fluctuations. We also report the much larger Pxx(f,θ)+Pyy(f,θ) which is (mostly) reduced from the Toroidal (Alfvenic, i.e., perpendicular to both B and k) fluctuations, and comprises most of the total power. These different components of the total power evolve and scale differently in the inertial range. We compare these elements of the magnetic power spectral tensor with “critical balance” model predictions

Flaw growth behavior in thick welded plates of 2219-T87 aluminum at room and cryogenic temperatures

Axial load fatigue and fracture tests were conducted on thick welded plates of 2219-T87 aluminum alloy to determine the tensile strength properties and the flaw growth behavior in electron beam, gas metal arc, and pulse current gas tungsten arc welds for plates 6.35 centimeters (2.5 in.) thick. The tests were conducted in room temperature air and in liquid nitrogen environments. Specimens were tested in both the as-welded and the aged after welding conditions. The experimental crack growth rate were correlated with theoretical crack growth rate predictions for semielliptical surface flaws

ESO 3060170 -- a massive fossil galaxy group with a heated gas core?

We present a detailed study of the ESO 3060170 galaxy group combining Chandra, XMM and optical observations. The system is found to be a fossil galaxy group. The group X-ray emission is composed of a central dense cool core (10 kpc in radius) and an isothermal medium beyond the central 10 kpc. The region between 10 and 50 kpc (the cooling radius) has the same temperature as the gas from 50 kpc to 400 kpc although the gas cooling time between 10 and 50 kpc (2 - 6 Gyr) is shorter than the Hubble time. Thus, the ESO 3060170 group does not have a group-sized cooling core. We suggest that the group cooling core may have been heated by a central AGN outburst in the past and the small dense cool core is the truncated relic of a previous cooling core. The Chandra observations also reveal a variety of X-ray features in the central region, including a ``finger'', an edge-like feature and a small ``tail'', all aligned along a north-south axis, as are the galaxy light and group galaxy distribution. The proposed AGN outburst may cause gas ``sloshing'' around the center and produce these asymmetric features. The observed flat temperature profile to 1/3 R_vir is not consistent with the predicted temperature profile in recent numerical simulations. We compare the entropy profile of the ESO 3060170 group with those of three other groups and find a flatter relation than that predicted by simulations involving only shock heating, S $\propto$ r$^{~ 0.85}$. This is direct evidence for the importance of non-gravitational processes in group centers. We derive the mass profiles within 1/3 R_vir and find the ESO 3060170 group is the most massive fossil group known (1 - 2 X 10$^{14}$ M$_{\odot}$). The M/L ratio of the system, ~ 150 at 0.3 R_vir, is normal.Comment: 17 pages, 12 figures, to appear in ApJ. A high-resolution version can be downloaded from http://cxc.harvard.edu/~msun/esoa.p