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Full-Text Articles in Physical Sciences and Mathematics

Triangulation And Finite Element Method For A Variational Problem Inspired By Medical Imaging, Tim Komperda, Enrico Au-Yeung Aug 2021

Triangulation And Finite Element Method For A Variational Problem Inspired By Medical Imaging, Tim Komperda, Enrico Au-Yeung

DePaul Discoveries

We implement the finite element method to solve a variational problem that is inspired by medical imaging. In our application, the domain of the image does not need to be a rectangle and can contain a cavity in the middle. The standard approach to solve a variational problem involves formulating the problem as a partial differential equation. Instead, we solve the variational problem directly, using only techniques available to anyone familiar with vector calculus. As part of the computation, we also explore how triangulation is a useful tool in the process.


Correlation Effects On Intramolecular C-H...Oh And O-H...O Hydrogen Bond Interactions In Azelaic Acid: An Ab Initio Study, Sabina Kalata, Alina Huang, Ruben Parra Aug 2021

Correlation Effects On Intramolecular C-H...Oh And O-H...O Hydrogen Bond Interactions In Azelaic Acid: An Ab Initio Study, Sabina Kalata, Alina Huang, Ruben Parra

DePaul Discoveries

Electron correlation effects on both conventional, O-H…O, and nonconventional, C-H…O, intramolecular hydrogen bonds present in a selected azelaic acid folded conformation were evaluated ab initio using HF and MP2 methodologies. The relative strength of the hydrogen bonds was examined through different indicators derived from geometry, vibrational frequencies, and electron density along the hydrogen bond path. The HF method results in weaker O-H…O and C-H…O hydrogen bonds when compared with the corresponding results using the MP2 method. Additionally, the stability of the folded azelaic conformation is found to depend on the level of theory used. Accordingly, the zero-point corrected energies of …


Insignificant Impacts Of Covid-19 Stay-At-Home Orders On Chicago Air Quality, Adam W.T. Steffeck Aug 2021

Insignificant Impacts Of Covid-19 Stay-At-Home Orders On Chicago Air Quality, Adam W.T. Steffeck

DePaul Discoveries

With the onset of the COVID-19 pandemic, reports of air quality improvements around the world resulting from the stay-at-home orders were widespread. However, for Chicago, no significant air quality improvements occurred despite large reductions in private vehicle transportation due to the lack of commuters. The city of Chicago is a nexus for long-haul transportation by trucks and trains, which did not decrease during the pandemic. These transportation sources use mostly diesel fuel engines and emit NOX, a precursor to tropospheric ozone, and PM2.5, both of which are harmful air pollutants. Using open access EPA air quality …


Depaul Discoveries Volume 10 Cover Art, Nicolette Listenbee Aug 2021

Depaul Discoveries Volume 10 Cover Art, Nicolette Listenbee

DePaul Discoveries

No abstract provided.


Research Focus: Pattern Recognition May 2021

Research Focus: Pattern Recognition

In The Loop

A CDM health informatics team joins a global race to advance COVID-19 diagnostics through X-ray insights.