Samuel Seekins '14
Carbon and Oxygen Stoichiometry of the Harvard Forest Ecosystem
In a world where there are many signs of current and future climate change it is crucial that we thoroughly understand how to model and interpret changes that we see in the environment around us. One commonly used method is to monitor and model the changing carbon dioxide levels known to be linked with temperature changes. Most current models assume a relatively simple model of carbon dioxide and oxygen flux. However, in ecosystems with diverse biological activity one cannot assume a constant consumption/production ratio if considering a plant’s need for water and nutrients. It is our opinion that current models can be improved and we would like to contribute to that improvement. Therefore we have collected air samples from the top canopy of the trees as well as mid-way to the ground and analyzed their CO2 and O2 concentration. The data collected has to be cut and refined to the point that it is presentable while excluding periods known to produce potentially poor data. Much of the behind the scenes work involved writing the code that would process the data and prepare it for analysis, graphing, etc. It is our hope that our tracking of these CO2 and O2 levels in this environment will assist the greater scientific community in using a more accurate way to analyze the stoichiometry of CO2 and O2 and generating predictions for the build-up of CO2 in the future.
Faculty Mentor: Mark Battle
Funded by the Maine Space Grant Consortium Fellowship
Michelle Burns '12
3-2 Engineering/Physics Honors Project
“Design, Construction and Calibration of a System to Precisely Measure Mechanical Properties of Mutable Collagenous Tissue and Connecting to Models of Viscoelastic Materials”
Mutable collageneous tissues, such as the dermis of a sea cucumber, have the ability to change mechanical properties behaviorally. In attempts to understand how the tissue alters from state to state, biologists typically use theoretical mechanical models and vibration tests to characterize the behavior of the tissue in its different states. As physicists, we approached both of these methods from a different perspective. We had two goals: 1) To investigate other potential spring-dashpot models using what is already known about the behavior of the sea cucumber dermis in its stiff, soft and standard states, and 2) To create an experimental setup different from the system used in biology to better characterize the mechanical properties of the dermis.
Noah Kent '12
Physics Honors Project
"Experimentally Observing the Onset of the Fractional Quantum Hall Effect as a Function of Temperature"
The fractional quantum hall effect occurs at very low temperatures in very high magnetic fields and is the result of when the conducting electrons of a sample become an incompressible fluid. This fluid behaves analogously to particles of fractional elementary charge created by the complex interactions of electrons in cyclotron orbits with magnetic flux quanta. Even though this phenomena was discovered in 1982 it is still not very well understood. Professor Syphers and I endeavored to experimentally observe the onset temperature of the fractional quantum hall effect in a Ga-As, Ga-Al-As semiconductor.