A dc servosystem including an ac motor

Closed loop servosystem for variable speed tape recorders on board spacecraf

Slow-speed drives for miniature devices

Hysteresis motor minimizes motor torque variations during shaft revolution when operated at high frequency and with a sinusoidal motor current. Motor speed is stabilized by a feedback servo

Promotion of innovative energy technologies in the glass industry by the European Commission

[no abstract available

Predictive modelling of gas assisted electron and ion beam induced etching and deposition

University of Technology Sydney. Faculty of Science.While the field of experimental micrometre scale EBIED / IBIED (“electron beam chemistry” or “ion beam chemistry”) has been growing in recent years, the 3D simulation of these systems at real scales has been non-existent. This type of simulation is important for it is only in three dimensions that interesting asymmetric and patterning phenomena can be tracked. There are a couple of difficulties in these types of simulations. One is solving the diffusion of adsorbate concentrations in the system. Accurate simulation of diffusion on general 2D surfaces is non-trivial, (even on 1D curves), and can require unnatural re-parametrization of the surface (re-meshing). Another difficulty is that simulations have generally been atomistic and limited in scale. The key to providing large scale 3D simulations comes from applying new, mathematically robust, computer-science methods based on implicit surfaces to this field. In this thesis, the issues above are addressed in a couple of different ways. In one case, diffusion over a complex surface was reduced to piecewise axially symmetric equations. Later, implicit methods for solving adsorbate kinetics continuum equations and evolving the surface are implemented, the closest point method and the level set method respectively. The development of the tools themselves is a non-trivial exercise as there are few software libraries for the level set method and none for the closest point method. These tools were then used independently to simulate etching and diffusion, as well as in concert to demonstrate the ability to simulate 3D deposition in the mass transport limited and reaction rate limited regimes

The role of cognitive maps in familiarity and wayfinding

Wayfinding is a difficult task that can be broken down into the interaction of a user with spatial information. It has been found that participants that are familiar with an environment are more successful at wayfinding than those that are not. It has also been found that participants that are familiar with an environment give wayfinding descriptions differently. This poster begins to examine familiarity in terms of the cognitive map. By exploring the formation of a cognitive map over time we can begin to examine the relationship between the cognitive map, familiarity with an environment, and wayfinding success. This poster outlines an experimental design for future work that examines these three areas togethe

The Integration of Character Education and its Impact on Teachers\u27 Professional Practice

Research on pre-service teacher training in character education is minimal at best, as is the case with research on best practices in pre-service education in general. What does exist suggests that there is a lack of pre-service training about specific character education strategies. There are few empirical studies investigating the effects of pre-service character education training as it applies to later practice in K-12 school settings. This study explored the perceptions of beginning teachers regarding their past preparation and current implementation of character education. Each participant graduated from a university in a Northwest state that currently implements character education in its pre-service curriculum. The research question was: Does the character education initiative at West University’s undergraduate pre-service program have an impact on its teacher education graduates’ current classroom practices? From this question four hypotheses were formed: (1) Graduates from West University’s pre-service undergraduate program perceive their pre-service character education as being effective for them as character educators; (2) Graduates from West University’s pre-service program feel competent to implement character education; (3) Graduates from West University’s pre-service program report using effective character education strategies in their current classrooms; and (4) Graduates from West University’s pre-service program perceive that they are effectively impacting their students’ character, citizenship and critical thinking skills. A mixed-methods design was employed starting with quantitative analysis of a survey that was distributed to teachers in their first five years of teaching after having graduated from the targeted university with a total of 31 respondents. The researcher then interviewed eight survey participants. The study revealed a mixed picture regarding the subjects’ sense of preparedness to implement character education. Quantitative data suggested that subjects felt competent to implement character education, as manifested in positive scores on the Character Education Efficacy Belief Instrument, but the qualitative data revealed the opposite. There was also a mixed picture of the use of character education strategies within their classrooms, with subjects reporting usage of some strategies but in a non-directive approach. The subjects also felt that they were affecting their students’ character, citizenship, and critical thinking skills but with limitations

The ecology of blacktail redhorse Moxostoma poecilurum in West Fork Thompson Creek, Louisiana

This study was designed to examine home range sizes and habitat use of blacktail redhorse Moxostoma poecilurum in West Fork Thompson Creek, Louisiana. Blacktail redhorse are a common non-game species found in Louisiana and other southeastern states. Adult blacktail redhorse (N=40; 187-273 mm total length) were implanted with radio transmitters and tracked twice weekly from February to September 2006 and from February to July 2007. To assess blacktail redhorse diet I analyzed 32 stomachs from fish collected by backpack electrofishing. I also conducted mark-recapture surveys of fish sampled monthly from May 2006 until July 2007. To assess homing ability in blacktail redhorse, I radio-tagged 10 individuals in 2007 and relocated them downstream (0.8 or 1.6 km) from their capture location. Results showed that implanted fish exhibited extremely high mortality or expulsion rates with 70% of all implanted transmitters being lost, even though retention rates in the laboratory were very high. On numerous occasions, I directly and indirectly observed avian and mammalian predators foraging in the study area, which likely explains high transmitter loss. Individual 95% linear home range sizes varied from 25 to 3,900 meters, with several fish having multiple home ranges, while others remained in the same pool throughout the study. Blacktail redhorse were observed foraging throughout the diel period, and their diet was primarily composed of chironomid (55%) and heptageniid larvae (17%). Similar to other redhorse species, blacktail redhorse were benthic feeders and foraging behaviors appear very similar to that of black redhorse Moxostoma duquesnei. Few marked individuals were recaptured (6 of 130) as indicated by mark-recapture sampling. The homing study showed only one individual moved back to its capture location. Small sample sizes and short study times limited both the mark-recapture and homing studies. Overall, blacktail redhorse exhibited a preference for pools with clay boulders, complex habitat, and undercut banks. The high levels of predation observed throughout this study and its impact on blacktail redhorse abundance suggest that local predation pressures structure this portion of the population and may be a driving force in structuring the entire headwater stream fish community in this area