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Speaker: Aiza Kabeer, 3rd year student, Applied Math
Title: Using models to explore debris flow dynamics
Abstract: Debris flows are moving masses of water, sediment, rock, and other particles that make them more dangerous than typical “flood” flows. Due to climate change, the frequency of wildfires is expected to increase, and debris flows are more likely to occur in steep burned watersheds. Because of a lack of data, it’s hard to define thresholds that will predict debris flow initiation and volumes with changes in rainfall and sediment concentration. I will discuss how we use models to explore how these thresholds change with respect to changes in sediment supply and topography. I will also talk about how we can use models to understand the dynamics of waves that influence the destructive power of debris flows. Model results help us explore the physical mechanisms controlling debris flows, which can improve situational awareness for post fire debris flow hazards.
Speaker: Lenox Baloglou, 1st year student, Applied Math
Title: Lambert's problem in orbital dynamics
Abstract: When considering space travel between two celestial bodies under a gravitational potential, Lambert's problem asks if there exists a way to free fall between the two bodies. The Lambert equation is a solution to this problem that relates travel time and the energy necessary for this fall to occur. Keplerian dynamics informs this further by stating that this free fall trajectory describes a conical arc. I will introduce the physical concepts of motion under a gravitational potential and a characterization of conic sections due to Apollonius in terms of a parameter known as eccentricity. Using conservation properties, I will show that free fall under a gravitational potential must follow a conical trajectory. Therefore, Lambert's problem can be rephrased as determining the energy required to place the vessel on the desired conical orbit connecting the two bodies. I will then show Lagrange's solution algorithm which yields the required energy as a function of the departure and arrival dates. I conclude by showing how this is a relevant problem in orbital mission planning.
Speaker: Rachel Dean, 1st year student, Applied Math
Title: Enhancing Dye-Sensitized Solar Cells with Anthocyanins
Abstract: Anthocyanins are naturally occurring pigments found in fruits and plants that can function as light-absorbing dyes in dye-sensitized solar cells (DSSCs). Conditions such as pH and molecular structure influence their ability to transfer energy to a semiconductor. This work examines a new molecular form of anthocyanin which enhances light absorption and energy transfer in DSSCs. I will describe the mechanisms of DSSCs and the chemical scheme of malonated anthocyanins to then analyse the distribution of species across the pH range. I will show that malonated anthocyanin species promote the coloured and reduce the colourless forms which leads to improved absorption of light across the pH range. The results suggest that our modified anthocyanins are beneficial to the production of energy from DSSCs. I conclude with our main findings and ideas for further study.