Physical Sciences and Mathematics Commons^™

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.

Using Methanol Masers To Probe High Mass Star Forming Regions, Naomi S. Shechter, Anuj P. Sarma

DePaul Discoveries

Compared to low mass stars, the formation of high mass stars is not well understood. To understand better how high mass stars form, we can utilize masers, naturally amplified point sources of microwave radiation. One example is the methanol maser, which falls into two categories. Class I methanol masers form in the bipolar outflows from the protostar, and Class II masers form in the accretion disk. Their compact size and intensity make them an excellent source of information about the process of high mass star formation. We compiled a modest database of Class I and II methanol masers through a …

An Investigation Of Water Masers In High Mass Star Forming Regions, Eleanor A. Webb

DePaul Discoveries

Within deep space are massive molecular clouds and within these molecular clouds, stars form. In these regions of star formation, masers can occur. I studied the presence of water masers within these high mass star forming regions. This was done in order to ascertain whether or not there is a correlation between the intensity of water masers versus the star formation activity within the molecular clouds. My findings provide answers to my specific research questions and includes information on the location of the water masers I observed with the star-forming regions. These findings provide information on water masers and sets …

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 …

High Altitude Ballooning As A Platform For Measuring Ozone Uptake Over Agricultural Landscapes, Thomas Sykora, Mark Potosnak

DePaul Discoveries

Measuring plant health is a key aspect in maximizing crop outputs. One often overlooked risk to crop fields is damage caused by stomatal ozone uptake; measuring this uptake is an important tool in understanding crop losses. Traditional methods for measuring plant ozone uptake are prohibitively expensive and rely on equipment that cannot easily be moved. Here, we propose high-altitude weather ballooning as a cost-effective alternative for measuring ozone uptake on a regional (~10 km) spatial scale. Ozonesounde data was obtained with weather balloons launched from the National Oceanic and Atmospheric Administration research station in Boulder, Colorado. This data was then …

Interspersed Denuded Zone (Idz): How Patchy Leaf Litter Dynamics In A Buckthorn-Invaded Urban Woodland Can Affect Microarthropod Species Richness, Angela Stenberg

DePaul Discoveries

Biodiversity loss may serve as a key diagnostic of the Anthropocene. An important driver of this loss is by means of invasive species. In this study of a forest preserve in Chicago, Illinois we examined Interspersed Denuded Zones (IDZs for short), which are areas of patchy leaf litter in invaded forests caused in this case by the rapid decomposition of litter from buckthorn (Rhamnus cathartica). We characterized the leaf litter mass in IDZs and enumerated litter-inhabiting microarthropod populations. We found that plots of high buckthorn density are associated with IDZs: there was significantly less leaf litter mass in …

Population Structure Analysis Of The Endangered Oak Quercus Brandegeei, Carolyn Brinckwirth

DePaul Discoveries

As humans continue to impact landscapes and ecosystems throughout the entire world, many plant and animal species have faced major changes in their environments. The rare endemic oak, Quercus brandegeei, is one such endangered species located in the Sierra La Laguna mountains of Baja California Sur, Mexico. This tree occurs solely on the ephemeral riverbeds of the mountains, which are inundated seasonally by hurricane waters. It is important to understand the fundamental characteristics, like spatial distribution, of Q. brandegeei in order to develop restorative management practices to protect this tree against extinction. Determining the geographic distribution of a species …

Modeling Reproduction Influencers Of An Endangered Oak, Camila Cortez

DePaul Discoveries

The endemic oak, Quercus brandegeei has been labeled as endangered by the IUCN Red List of Endangered Species due to its limited genetic diversity and lack of regeneration. The oak (Quercus) species is a keystone species in many parts of the world and has been facing various challenges to their survival (Westwood 2017) making efforts to support and protect endemic oaks all the more ecologically and socially imperative. There are challenges to identifying threats as there are many unknown characteristics of Q. brandegeei’s biology that are essential to carrying out conservation efforts. To develop a greater understanding of …

Carbon Storage And Valuation Of Ecosystem Services On A Restored Urban Forest In Northeastern Illinois, Madeline Mertes, Bailey Didier

DePaul Discoveries

Urban forests provide a multitude of different valuable ecosystem services, such as carbon sequestration and air pollutant removal. However, urban forests are also at risk due to negative impacts brought on by climate change and the increased presence of invasive species. In this natural experiment, 3 transects of land in Prairie Wolf Slough, Highland Park, Illinois was monitored over the course of 4 years in order to evaluate demographic changes. The estimated total whole tree biomass for the forest was calculated to be 115,420.4 kg in the year 2016 and 115,154.0 kg for the year 2020. The total amount of …

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 NO_X, a precursor to tropospheric ozone, and PM_2.5, both of which are harmful air pollutants. Using open access EPA air quality …

Depaul Discoveries Volume 10 Cover Art, Nicolette Listenbee

DePaul Discoveries

No abstract provided.

Sparse Domination Of The Martingale Transform, Michael Scott Kutzler

Mathematics & Statistics ETDs

Linear operators are of huge importance in modern harmonic analysis. Many operators can be dominated by finitely many sparse operators. The main result in this thesis is showing a toy operator, namely the Martingale Transform is dominated by a single sparse operator. Sparse operators are based on a sparse family which is simply a subset of a dyadic grid. We also show the A2 conjecture for the Martingale Transform which follows from the sparse domination of the Martingale Transform and the A2 conjecture for sparse operators.

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Effect Sizes And Intra-Cluster Correlation Coefficients Measured From The Green Dot High School Study For Guiding Sample Size Calculations When Designing Future Violence Prevention Cluster Randomized Trials In School Settings, Md. Tofial Azam, Heather M. Bush, Ann L. Coker, Philip M. Westgate

Biostatistics Faculty Publications

Purpose: Cluster randomized controlled trials (cRCTs) are popular in school-based research designs where schools are randomized to different trial arms. To help guide future study planning, we provide information on anticipated effect sizes and intra-cluster correlation coefficients (ICCs), as well as school sizes, for dating violence (DV) and interpersonal violence outcomes based on data from a cRCT which evaluated the bystander-based violence intervention ‘Green Dot’.

Methods: We utilized data from 25 schools from the Green Dot High School study. Effect size and ICC values corresponding to dating and interpersonal violence outcomes are obtained from linear mixed effect models. We …

Growth-Profile Configuration For Specific Deformations Of Tubular Organs: A Study Of Growth-Induced Thinning And Dilation Of The Human Cervix, Kun Gou, Seungik Baek, Marvin M.F. Lutnesky, Hai-Chao Han

Mathematics Faculty Publications

Growth is a significant factor that results in deformations of tubular organs, and particular deformations associated with growth enable tubular organs to perform certain physiological functions. Configuring growth profiles that achieve particular deformation patterns is critical for analyzing potential pathological conditions and for developing corresponding clinical treatments for tubular organ dysfunctions. However, deformation-targeted growth is rarely studied. In this article, the human cervix during pregnancy is studied as an example to show how cervical thinning and dilation are generated by growth. An advanced hyperelasticity theory called morphoelasticity is employed to model the deformations, and a growth tensor is used to …

Temperature Tides Across The Mid-Latitude Summer Turbopause Measured By A Sodium Lidar And Mighti/Icon, Tao Yuan, M. H. Stevens, C. R. Englert, T. J. Immel

All Physics Faculty Publications

Local full diurnal coverage of temperature variations across the turbopause (∼90–115 km altitude) is achieved by combining the nocturnal observations of a Sodium (Na) Doppler lidar on the Utah State University (USU) campus (41.7°N, 248.2°E) and NASA Michelson interferometer for global high-resolution thermospheric imaging (MIGHTI)/Ionospheric connection explorer (ICON) daytime observations made in the same vicinity. In this study, utilizing this hybrid data set during summer 2020 between June 12th and July 15th, we retrieve the temperature signatures of diurnal and semidiurnal tides in this region. The tidal amplitudes of both components have similar vertical variation with increasing altitude: less than …

Solar Thermal Cooling System: A Feasible Option For The Maldives, Ahmed Fathhee

International Programs

This poster presents the potentiality of utilizing solar and converting thermal energy to cool buildings in the Maldives. A thermal model of a typical building showing the annual cooling load is presented which was used to run a simulation model of a solar thermal cooling system. Simulation data shows that it is possible to use a solar thermal cooling system to cool the buildings effectively.

Impact Of Weak Gravitational Force In Sri Lanka, Periyandy Thunendran

International Programs

Gravity studies explain about the sub surface features and shape of the earth, and show gravitational force is weak in the Sri Lanka region, which has positive and negative impacts. This poster argues further studies on gravity are needed to revise the global gravitational model of the region.

Evaluation Of Capacity Building For Forage And Livestock Production In Laos, Viengxay Photakoun

IGC Proceedings (1993-2023)

No abstract provided.

The Creeks And Communities Strategy: Accelerating Cooperative Riparian Restoration, Sandra Wyman, Sherman Swanson, Laura Van Riper

IGC Proceedings (1993-2023)

No abstract provided.

Investigation Of The Energy Source For An Early Dynamo In Vesta From Experiments On Electrical Resistivity Of Liquid Fe-10wt%Ni At High Pressures, Eric M. Lenhart

Electronic Thesis and Dissertation Repository

Investigation of energy sources in an early dynamo in Vesta has been carried out using high pressure-temperature experimental studies. Electrical resistivity of Fe‐10wt%Ni was measured at 2-5 GPa up to 2082 K in the liquid state and compared to previous results of pure Fe and pure Ni. Thermal conductivity was calculated from electrical resistivity to determine adiabatic core heat flux. The results are applied to determine whether thermal convection could be responsible for the putative dynamo in early Vesta’s core. An adiabatic core heat flux of ~300 MW at the top of Vesta’s core is estimated from this study and …

Memories Of Professor Hiroshi Kunita, Ichiro Shigkeawa

Journal of Stochastic Analysis

No abstract provided.

On The Works Of Hiroshi Kunita In The Sixties, Masatoshi Fukushima

Journal of Stochastic Analysis

No abstract provided.

Personal Memories Of Hiroshi Kunita, David Elworthy

Journal of Stochastic Analysis

No abstract provided.

Preface, Shigeki Aida, David Applebaum, Yasushi Ishikawa, Arturo Kohatsu-Higa, Nicolas Privault

Journal of Stochastic Analysis

No abstract provided.

An Introduction To Calling Bullshit: Learning To Think Outside The Black Box, Jevin D. West, Carl T. Bergstrom

Numeracy

Bergstrom, Carl T. and Jevin D. West. 2020. Calling Bullshit: The Art of Skepticism in a Data-Driven World. (New York: Random House) 336 pp. ISBN 978-0525509202.

While statistical methods receive greater attention, the art of critically evaluating information in everyday life more commonly depends on thinking outside the black box of the algorithm. In this piece we introduce readers to our book and associated online teaching materials—for readers who want to more capably call “bullshit” or to teach their students to do the same.

For The Love Of Mathematical Research: A Conversation With Undergraduate Research Students, Mike Janssen

Faculty Work Comprehensive List

"One of my passions as a professor is creating opportunities for students to ask questions about mathematics."

Posting about students' perspectives on mathematics research from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation.

https://inallthings.org/for-the-love-of-mathematical-research-a-conversation-with-undergraduate-research-students/

The Variability Of Seawater Carbonate Chemistry In Two Florida Urban Mangrove Ecosystems, Alexandrina R. Rangel

All HCAS Student Capstones, Theses, and Dissertations

Anthropogenic carbon dioxide (CO₂) emissions into the atmosphere are yielding serious impacts across the world’s ocean, including ocean acidification, sea level rise, and increasing seawater temperature. However, these changes are not occurring uniformly across all marine ecosystems. Coastal ecosystems, such as mangroves, already experience extreme and variable environmental conditions due to natural biogeochemical and physical processes. The goal of this study was to document small-scale variability in two urban mangrove ecosystems to gain insight into how ocean acidification will manifest within these systems. Using a stand-up paddleboard, a suite of sensors, and traditional bottle sampling techniques, we measured …

Physics Of Martial Arts: Incorporation Of Angular Momentum To Model Body Motion And Strikes, Alexis Merk, Andrew Resnick

Physics Faculty Publications

We develop a physics-based kinematic model of martial arts movements incorporating rotation and angular momentum, extending prior analyses. Here, our approach is designed for a classroom environment; we begin with a warm-up exercise introducing counter-intuitive aspects of rotational motion before proceeding to a set of model collision problems that are applied to martial arts movements. Finally, we develop a deformable solid-body mechanics model of a martial arts practitioner suitable for an intermediate mechanics course. We provide evidence for our improved model based on calculations from biomechanical data obtained from prior reports as well as time-lapse images of several different kicks. …

Nickel Catalyzed Electrochemical C-C Cross-Coupling Reactions, T. Leo Liu

Funded Research Records

No abstract provided.

Replication Data For: Goehring Et Al., "The Transport History Of Alluvial Fan Sediment...", Nathan Brown

Earth & Environmental Sciences Datasets

This data repository contains: A) MATLAB source code B) Sample locations and chemical measurements used for Be-10 and C-14 analysis C) Dose recovery test results for luminescence protocol D) Sample locations and dosimetry information for luminescence samples.