2 resultados para concepts of power

em Memorial University Research Repository


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Some dads wear nail polish! Is the tooth fairy a boy or a girl? My Grade Two students’ voices were integral in developing each of the action research cycles as students became co-creators of knowledge. I gathered data through a personal journal, observations, reflections, work samples, interviews and classroom artifacts. The research question was focused on creating a safe and caring classroom environment by selecting appropriate instructional strategies based on developing my students’ concept of gender. Findings included students’ acceptance of differences, emulation of gender stereotypes, the significance of role models and student empowerment. Conclusions examined the influence that behaviour has on instructional strategies, creating allies among primary students, the importance of teacher training and the influence that students have in their classroom. Thoughts towards future research include the need for further parent engagement and more exploration of the impact that the school environment has in the classroom.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Solid Oxide Fuel Cell (SOFC) is a class of fuel cells that is capable of generating very high levels of power at high temperatures. SOFCs are used for stationary power generation and as Combined Heat and Power (CHP) systems. In spite of all the beneficial features of the SOFC, the propagation of ripple currents, due to nonlinear loads, is a challenging problem, as it interferes with the physical operation of the fuel cell. The purpose of this thesis is to identify the cause of ripples and attempt to eliminate or reduce the ripple propagation through the use of Active Power Filters (APF). To this end, a systematic approach to modeling the fuel cell to account for its nonlinear behavior in the presence of current ripples is presented. A model of a small fuel cell power system which consists of a fuel cell, a DC-DC converter, a single-phase inverter and a nonlinear load is developed in MATLAB/Simulink environment. The extent of ripple propagation, due to variations in load magnitude and frequency, are identified using frequency spectrum analysis. In order to reduce the effects of ripple propagation, an APF is modeled to remove ripples from the DC fuel cell current. The emphasis of this thesis is based on the idea that small fuel cell systems cannot implement large passive filters to cancel the effects of ripple propagation and hence, the compact APF topology effectively protects the fuel cell from propagating ripples and improves its electrical performance.