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Derivation Of The Hellinger-Reissner Variational Form Of The Linear Elasticity Equations, And A Finite Element Discretization, Bram Fouts Jan 2018

Derivation Of The Hellinger-Reissner Variational Form Of The Linear Elasticity Equations, And A Finite Element Discretization, Bram Fouts

REU Final Reports

In this paper we are going to derive the linear elasticity equations in the Strong Form to the Hellinger Reissner Form. We find a suitable solution to solve our stress tensor. Then we will use finite element discretization from. We will run tests on a unit cube and multiple other shapes, which are described at the end. We view the different magnitudes of the displacement vector of each shape.


Deciphering The Rules Of Cell-To-Cell Coupling By Molecular Modeling And Simulation, Linda D. Lee Jan 2018

Deciphering The Rules Of Cell-To-Cell Coupling By Molecular Modeling And Simulation, Linda D. Lee

REU Final Reports

Intercellular communication is vital for quick adjustments and maintenance for cell function and development. Gap junctions are membranes channel proteins that enable this direct communication between adjacent cells throughout the body. The compatibility of connexins (Cx), which make up a gap junction, determines whether a gap junction can form. Though many studies show which connexins are compatible, the molecular basis is not known (Bai & Wang, 2014). Through computational modeling, we identify the residues that energetically contribute most favorably at the docking interface of homotypic and heterotypic combinations of Cx43, Cx46, and Cx50 gap junctions. However, due to instability of …


Day Laborers & Extreme Heat: Recommendations For Reducing Heat Stress, Sandra Mena Jan 2018

Day Laborers & Extreme Heat: Recommendations For Reducing Heat Stress, Sandra Mena

REU Final Reports

The Intergovernmental Panel on Climate Change (IPCC) has various Global Climate Models (GCM). One of them, models three greenhouse gases. The increasing amount of greenhouse gases are just a fraction of factors that fuel global climate change. According to the IPCC 2014, climate related extremes such as heatwaves are likely to occur more regularly and are likely to increase in duration. Since 1979, there has been over 9000 deaths that occurred from heat-related incidents in the United States (U.S. Environmental Protection Agency, 2016). Which brings attention to population groups who are exposed to hot temperatures on a frequent basis due …


Effects Of Land Development And Season On Heavy Metal Concentrations In Urban Streams, Helen Daigle Jan 2018

Effects Of Land Development And Season On Heavy Metal Concentrations In Urban Streams, Helen Daigle

REU Final Reports

Although it is generally understood that urban development can impact the quality of urban streams, there are many factors that affect the concentrations of pollutants being transferred from the built environment to a given output. This study examines the impact of land use surrounding urban streams, specifically, the degree of development and presence or absence of green infrastructure (GI) in these areas on heavy metal (HM) concentrations in Portland, Oregon. After collecting 1021 water quality samples from 2010-2018, we examined the difference in concentrations of HM pollutants across different combinations of land use and season. Increased levels of calcium, magnesium, …


Hydro-Climatological Summer Trends In The Continental United States, Naya Mairena Flores Jan 2018

Hydro-Climatological Summer Trends In The Continental United States, Naya Mairena Flores

REU Final Reports

We investigated trends in air temperature, stream temperature and discharge for rivers across the continental United States from the summer months of 1996 to 2016. Using GAGES II from USGS and PRISM and programming language R we analyzed specific hydrological trends in Mann-Kendall’s tests. After collecting the slope values whether they were negative or positive and the P-Values, the significance of that slope, we mapped slopes of trends in GIS. Stream temperature increased 12% of stations across the summer, while air temperature increased 22% of stations, and discharge decreased 15% of stations, respectively. Seven day moving average of daily maximum …


Water Quality Factor Prediction Using Supervised Machine Learning, Kathleen Joslyn Jan 2018

Water Quality Factor Prediction Using Supervised Machine Learning, Kathleen Joslyn

REU Final Reports

The objective of this research is to explore prediction accuracy of water quality factors, with techniques and algorithms in machine learning consisting of a variation of support vector machines - Support Vector Regression (SVR) and the gradient boosting algorithm Extreme Gradient Boosting (XGBoost). Both the XGBoost and SVR algorithms were used to predict nine different factors with success rates ranging from 79% to 99%. Parameters of these algorithms were also explored to test the prediction accuracy levels of individual water quality factors. These parameters included normalizing the data, filling missing data points, and training and testing on a large set …