Summer Interdisciplinary Research Symposium (SIReS)

The 2021 Summer SIReS (Summer Interdisciplinary Research Symposium) will take place on Friday, July 23 from 8:30 a.m. – 12:30 p.m. in the Harre Union Ballroom A. The schedule is below. You can scroll down to see the poster presentations and abstracts.

8:30 a.m. – 9:45 a.m. Poster Session 1

10:00 a.m. – 11:15 a.m. Keynote Speaker: Dr. Karin Calvinho, Chief Technology Officer, RenewCO2

“Making Materials and Chemicals from Carbon Dioxide”

Electrochemical reduction of carbon dioxide, powered by renewable electricity, enables the sustainable production of chemicals, monomers, and fuels, potentially displacing fossil carbon sources and mitigating the effects of global warming. However, the activation of CO2 is a kinetic bottleneck for this process. Low energy efficiencies and poor product selectivity prevent the commercial use of this technology to synthesize products with more than one carbon. As such, we sought to develop viable catalysts for the CO2 reduction reaction (CO2RR) that 1) operate at high energy efficiency; 2) are capable of catalyzing C-C coupling for producing high-value chemicals; 3) are synthesized from earth-abundant materials, and 4) are robust and stable for extended lifetimes. Inspired by nature’s formate and carbon monoxide dehydrogenases, we investigated the CO2RR activity of seven different transition metal phosphides. Furthermore, we applied experimental and theoretical tools to unravel reaction mechanisms and extract design principles that can guide the development of next-generation catalytic materials. Ni2P emerged from our research as the most promising catalyst, operating at exceedingly low overpotential (∼10 mV), yielding no hydrogen by-product at 0V vs. RHE, and forming non-volatile C3 and C4 monomers. The discovery of the catalyst prompted us to investigate the technology’s potential for translation to a commercial process. Through customer interviews, we found wide interest in carbon-negative processes to offset industrial CO2 emissions. As a result, RenewCO2 was born as a spinout from Rutgers University. Today, the startup is developing a pilot-scale process to produce plastic precursors from CO2 with funding from the Department of Energy.

11:15 a.m. – 12:30 p.m. Poster Session 2

Poster Session 1: 8:30-9:45 am

The Effects of Estrogen (E2) on the Filamentous Growth of Candida albicans on Assorted Solid Medias

Paige M Camp, George C Gundelach, Patrice Bouyer, Micheal Keviin Watters | Biology | BIO-1

Candida albicans is a commensal yeast that lives within the human body. When exposed to specific environmental stimuli (ex. pH, temperature) the fungi will undergo a morphological change from yeast to filamentous (hyphal). Currently, C. albicans is the most prevalent human fungal pathogen, causing both mucosal and systemic infections. This infection, called candidiasis, can endanger high-risk groups, such as immunocompromised patients. While studied extensively, the relationship between C. albicans hyphal growth and estrogen (E2) has yielded mixed results amongst researchers. In our research, we attempted to provide clarity to this relationship by using a variety of solid media and studying how each affects E2’s influence on hyphal development. We used three solid media; Minimum, Spider, and YEPD. In our experiments, we found that C. albicans undergoes three distinct morphologies and variable behavior between the three media types. In Minimum media, we found that E2 is blocking filamentous growth after day two compared to no E2. In Spider media, E2 is blocking filamentous growth up to day three compared to no E2. Finally, in YEPD, E2 inhibits filamentous growth only at day two compared to no E2. In our conditions, E2 has an inhibitory effect on filamentous growth. Furthermore, our observations suggest that the inhibition is media-dependent. Currently, we are testing fetal bovine serum (FBS), which is known to induce filamentation, as a positive control to compare to the effects of E2.

Effects of Environmental Factors on Candida albicans Morphology: A Focus on Estrogen and Microgravity

Sky Kaur, Anita Coleman, Riquail Gibson, Idalia Zachara, Paige Camp, George Gundelach, Michael Watters, Patrice Bouyer | Biology | BIO-2

During body invasion, C.albicans change their morphology from yeast to filamentous, but the environmental factors responsible for the change in morphology are not well characterized. During Sepsis, high levels of estrogen (E2) are recorded (~0.1 nM), in addition during spaceflight it has been shown that C.albicans become virulent. In this study, we aimed at characterizing the effect of estrogen and microgravity as environmental factors inducing filamentous growth. In our experiments, we grow C.albicans in minimum liquid media and use brightfield microscopy to observe the morphology. Microgravity is simulated using a clinostat. In an experimental series, we tested the effect of FBS (positive control) and estrogen on filamentous growth. We found that in the control only 1 out of 10 slides showed filaments. In the presence of FBS, we found filamentous growth in 10 out of 10 slides. In the presence of estrogen, filaments were observed in 8 out of 10 slides. In addition to FBS, the combination of FBS + E2 we found filament growth in 10 out 10 of the slides. However, in the presence of microgravity, we observed filaments in 9 out of 10 slides, meanwhile, we only observed 4 out of 10 slides without microgravity. In addition to microgravity, the combination of E2 + Microgravity, filaments were observed in 3 out of 10 slides. Meanwhile, we only observed 4 out of 10 slides with just E2. In conclusion, estrogen does not inhibit filament growth stimulated by FBS, but it prevents filamentous growth in microgravity.

Fungal Digestion of Microplastics

Maranda Powell, Heather Wendland, Megan Moretti, Deuce LaRose | Biology | BIO-3

Plastic pollution has been a growing concern ever since the first mass produced form of synthetic plastic was created in 1907. The extent and effects associated with decades of plastic and microplastic pollution are the focus of current scientific studies, and methodology to quantify and identify the presence of microplastics in both land and aquatic environments. The purpose of this study is to determine the best conditions to degrade microplastics effectively. This was determined through the use of several forms of Fungi to observe and report changes in the microplastics, as well as possible changes in the microplastics due to prior environmental exposure such as heat that can affect the digestion.

Understanding vertebrate embryonic development under conditions present in outer space

Neil Singh, Michael A Berberoglu | Biology | BIO-4

The ability of humans to survive, thrive, and sustain life in outer space requires that human embryos develop normally under conditions such as microgravity. We are using the zebrafish model system due to the fact that they share similarities with humans during development. The larval zebrafish will be used to assess embryonic and neural development under simulated microgravity conditions, with specific focus on neural development which has not been well studied. Before performing these experiments, it is critical that histological procedures, including cryosectioning and immunohistochemistry, are up and running in our lab for stages of early zebrafish development. This includes immunohistochemistry for the neuronal marker HuC/D (commonly used to label neurons in zebrafish), and RNA-binding proteins Rbfox1l and Rbfox2 (label neuronal populations). Cryosectioning of 7 day post-fertilization (dpf) larval zebrafish was performed, followed by immunohistochemistry for HuC/D in conjunction with Rbfox labeling, and samples will be imaged on a compound fluorescent microscope to determine whether the protocol is working. Our work aims to better understand vertebrate embryonic development under conditions present in outer space.

Structural Damage Detection Using Machine Learning Techniques

Zhuolin Yuan | Civil and Environmental Engineering | CEE-1

In order to ensure the integrity of the structure, timely and accurate detection and identification of structural damage during and after an extreme event or over the lifetime of a structure is a very important for safety and economic resons. Structural damage detection and identification techniques can be generally classified into two main categories based on whether they use dynamic or static test data. This research project will use convolutional neural networks, which will focus on leveraging the capabilities of several models and toolkits, including AlexNet, Tensorflow and Pytorch. We will establish baseline performance metrics for an existing CNN-based program using a static image set of classified bolt, corrosion and crack damages. Investigate the application of machine learning methods to improve the performance of the CNN-based program on identifying damage. Investigate the performance of the modified CNN-program on new image data set that are collected real-time using a drone.

Synthesis of A. Mexicana Inspired Antimicrobial Agents

Jessica Villegas, Bryce Ball, Jeffrey Pruet | Chemistry | CHEM-1

Bacterial and fungal infections occur when microorganisms invade the tissue and, if left untreated, can affect the whole body. Pathogenic bacterial and fungal infections are some of the leading causes of death in the population at large. Due to the ever-growing prevalence of drug-resistant “superbugs” and the lack of new antimicrobial drugs, there is a need to explore new and alternative pathways for fighting these diseases. Through a collaborative project, we have explored separation of key components of the seed, stem, leaves, and root of the Argemone mexicana plant to isolate antimicrobial agents found within this plant. We have already identified three key molecules which give this plant anti-microbial properties against gram-positive bacteria. We are now focused on designing and synthesizing new variants of these bioactive molecules in the hopes of discovering new, more potent, drugs.

Quantifying and Analyzing Synthetic Microfiber Pollution in Great Lakes Sediment near Cladophora Mats

Antigone N Wilson, Eathan Faust, Julie Peller | Chemistry | CHEM-3

Microfiber pollution is ubiquitous in aquatic environments. Synthetic microfibers, a major class of microplastics, such as polyester, rayon, acrylic, and nylon, are present in clothing and other textile items, and are now viewed as contaminants of emerging concern. Routine laundering of synthetic fabrics has contributed to massive microfiber contamination in surface waters. In addition to its presence in water and sediment, previous microfiber research by our group showed that Great Lakes Cladophora, a common macroalgae, entangles and adsorbs microfibers in much greater amounts. This research aims to assess the role of the lake sediment below and near Cladophora mats in the fate of these microplastics. To determine if this sediment traps synthetic microfibers, research was conducted with sediment samples collected by the United States Geological Survey (USGS). Samples were cleaned using a ZnCl2 solution for density separation, which suspends most microfibers from the heavier sediment. All samples were then subjected to an advanced oxidation technique, which generates hydroxyl radicals that decompose most natural organic materials, including natural fibers. Microscopic analysis was implemented to quantify synthetic microfibers. The early analyses indicate that the lake sediment does not have entanglement or adsorbent properties. Due to the ubiquitousness of microfibers, method blanks were implemented to determine the amount of microfiber contamination introduced in the lab and suggest some work is still needed to reduce external contamination. A range of 0 to 12 microfibers (Av = 7) have been found in the samples per average dry weight of 32.091 g.

The Wifi Pineapple – The Forbidden Fruit of Networking

Daniel Hautzinger | Computing and Information Sciences | CIS-1

This project conducted a careful investigation into the capabilities of the Hak5 Wifi Pineapple Mark VII, which is a commercially available security and testing apparatus for wireless networks. This device has been used by cybersecurity engineers and companies to audit the networks of many different businesses. A key question of this investigation was whether the device is suitable for use in classroom environments. The risks, side effects, and propriety of the Pineapple were of particular focus. This project also investigated the ethical and legal implications that might arise from use or even casual reception of signal. The investigation concluded that the Wifi Pineapple Mark VII is only suitable for carefully supervised or monitored use. Regardless of the user’s intent, the impact and damage that this high-risk tool can cause to nearby devices makes it much too dangerous to use in a classroom environment.

Community Risk Assessment for the Valparaiso Fire Department

Ashley Darnell | Mathematics and Statistics | MATH-1

In recent years, many fire departments across the nation have begun to adopt the use of predictive analytics to identify the type and location of fires that are most likely to occur in order to more efficiently allocate resources. This project is a collaboration between Valparaiso University and the Valparaiso Fire Department to perform a community risk assessment for the city of Valparaiso. The initial steps for this project were to organize and clean the data, which included inputting missing property values and correcting data entry errors. We then conducted exploratory data analysis. In particular, we created tables showing the amount of property that had been saved by the Valpariso Fire Department from 2016-2020, the span of their data, in order to highlight the positive benefits of their work. We also computed the frequency of various EMS dispatch complaints and analyzed their trends over time so that the Valparaiso Fire Department can better train and prepare their EMS personnel.

Collecting Data on Brightness Variations in the Central Stars of Planetary Nebulae Using Sky Surveys

Emily Pavasars | Physics and Astronomy | PHYS-1

Research on planetary nebulae is shifting from the source of their fascinating shapes to details on how those shapes are created. The overall goal of this project is to measure the fraction of planetary nebulae that have binary central stars. In order to do this, a large amount of data is required. So we took the list of planetary nebula targets identified in Gaia data and a list of nearby, known planetary nebulae and ran them through available online databases. These databases provide data on the brightness of these stars over time. For over 2,000 objects from the Gaia list, the Catalina Sky Survey (CSS) had data on 35 of them. 16 objects exhibited possible variability. Using the Palomar Transient Facility (PTF) and the Zwicky Transient Facility (ZTF) databases, only 4 of those appeared in the PTF and 6 in the ZTF. We narrowed the initial Gaia list to only objects with magnitudes from V = 14-16 and ran them through the All-Sky Automated Survey for Supernovae (ASAS-SN). Out of 123 objects, we found data for 96. We ran the entire list of nearby objects through ASAS-SN and found data for 113 objects of 167. We ran period searches on the data found from ASAS-SN using Period04. 14 of the objects from Gaia and 28 of the objects from the nearby objects list looked potentially variable. We present here results on some of the detected variables, preliminary statistics and a discussion of the search process.

Searching for Periodicity in Protoplanetary Nebula

William Bakke | Physics and Astronomy | PHYS-2

Protoplanetary Nebula (PPNe) are a stage of stellar evolution that falls between the Asymptotic Giant Branch Stars and Planetary Nebula (PNe) stages. Many PPNe tend to display a cyclical variation in their brightness. In a 2010 paper by Dr. Bruce Hrivnak, he reported initial periods of twelve PPNe. My goal for the summer is to confirm or refine the periods for six of those PPNe, along with finding possibly new secondary periods within the light variation of these six PPNe. These objects have been reanalyzed due to the availability of new, publicly available All-Sky Automated Survey for Supernova (ASAS-SN) data and new data from the Valparaiso University Observatory. In order to go about this analysis, I have begun with photometric data gathered from the ASAS-SN online database. This data is reduced, then analyzed through a period search program known as Period04. Period04 fits a Fourier Series to the data, allowing us to find the most likely frequency of variation, and thus the period at which the PPNe is varying at. This will then be followed by a similar analysis of the new VUO data. In this poster, I will be presenting the periods and amplitudes found by this study, and comparing them to the previously found results. Periods of ~81 days were found in two of the stars, with another found for a third star, with a period between 220-290 days.

This research is supported by a REU grant from the National Science Foundation.

Updating Analyses 6 Proto-Planetary Nebulae

Peyton Grimm | Physics and Astronomy | PHYS-3

My research was conducted on proto-planetary nebulae and attempted to find one or multiple periods to their brightness. Proto-Planetary Nebulae (PPNe) are stars late in their evolution in transition between the second red giant phase and the planetary nebulae phase. They are known to pulsate, and some have been found to have multiple periods to their pulsation. The goal of this research is to find these periods so that we may better understand the internal properties of PPNe. I conducted my research under the guidance of Professor Bruce Hrivnak. The six stars I researched have been previously studied by him and documented in his paper Variability in Proto-Planetary Nebulae I. Light Curve Studies of 12 Carbon-Rich Objects (Hrivnak et al. 2010). I have updated the analyses of these stars using new data from the All-Sky Automated Survey for Supernovae in addition to the Valparaiso University Observatory. To analyze my PPNe candidates, I studied their light curves (brightness over time) using a period searching program called Period04. The stars I have researched show cyclical variability with at least one period associated with it. A few of my stars indicate two different periods with patterns of constructive and destructive interference. The periods for my stars range between 80 and 160 days. None of my stars have shown evidence for long-term (multi-year) periods. Long-term periods have been observed in some PPNe and are thought not to be associated with pulsation but possibly with binarity. This research is supported by an NSF REU grant.

Poster Session 2: 11:15 am – 12:30 pm

Identifying Antimicrobial Phytocompounds to Combat ISS Superbugs

Alexis Dres, Katelyn Shouse, Danielle Orozco-Nunnelly, Jeffrey Pruet | Biology | BIO-5

The isolation, or creation, of novel antimicrobial agents is currently at the forefront of modern healthcare due to the stark decrease in antimicrobial drug development in recent years and due to the increasing rise of superbugs, or microorganisms that are resistant to more than one type of antimicrobial treatment, which are predicted by 2050 to cause 10 million deaths/year. In addition to being a terrestrial cause for concern, antimicrobial resistant microbes are also a threat to the health of the individuals on the International Space Station (ISS). According to recent studies, a diverse population of bacteria and fungi, including several opportunistic pathogens, have colonized the ISS, and many of these strains have been found to possess antimicrobial resistance genes. Therefore, our research is focused on testing bacterial and fungal pathogens that have been isolated from the ISS against methanolic extracts from different medicinal plants, such as Argemone mexicana and Curcuma longa. Additionally, from previous work in our lab (https://doi.org/10.1371/journal.pone.0249704), we have identified several antibacterial compounds in A. mexicana and are attempting to determine the distribution of these phytocompounds (berberine, chelerythrine, sanguinarine) in the plant using quantitative chemistry techniques. This work highlights the importance of plants as an invaluable pharmaceutical resource at a time when antimicrobial drug discovery has plateaued.

The Genetic Analysis of Cortical Bone Morphology in Mice

Sydney Martens, Jane Kenney-Hunt | Biology | BIO-6

Osteoporosis is a disease that affects bone mass and thickness, which ultimately leads to bone fracture. It is known that decreased cortical thickness and bone area are associated with the development of osteoporosis. We analyzed genetic effects on cortical bone thickness, cortical bone area and polar moment of inertia in the femora and radii of 17 recombinant inbred mouse lines. The quantitative trait locus (QTL) analysis of the recombinant mice indicates regions of the genome that have effects on the specific trait. Identification of QTL in sex and diet isolated experiments can indicate gene by environment interactions. 423 mice from 17 LG/J and SM/J cross lines were provided with either a low-fat or high-fat diet for 20 weeks. After necropsy, bone area and thickness were collected from microCT images. Results from genetic analysis revealed three QTL affecting bone area, three QTL determining cortical thickness and four QTL that influence polar moment of inertia. These QTL demonstrate the genetic effects on bone structure interacting with the effects of dietary fat and sex.

Molecular Mechanisms that establish the eye-specific visual projection

Elaina Baker, Masaru Nakamoto | Biology | BIO-7

Correct functioning of the nervous system critically depends on the formation of the precise neuronal network. For example, axons of retinal ganglion cells from the right and left eyes project to different domains in the lateral geniculate nucleus of the thalamus. This eye-specific retinogeniculate projection provides the anatomical basis for binocular vision. Nell2 (neural epidermal growth factor (EGF)-like-like-2) is an extracellular glycoprotein that is predominately expressed in the nervous system. Our lab has previously shown that Nell2 acts as an inhibitory axon guidance molecule in the establishment of the eye-specific retinogeniculate projection. The current work aims to identify the Nell2 receptor in the retinal axon guidance. By using immunohistochemistry, we found that the receptor tyrosine kinase Ros1, which binds to Nell2, is express in the developing chick retinal ganglion cells. Our results suggest that Ros1 may act as a receptor for Nell2 in the retinal ganglion cells and play a significant role in the establishment of the eye-specific retinogeniculate projection.

Hydroelectricity as a Viable Renewable in the United States

Georgia Martin | Business Administration | BUS-1

In the United States, the West is burning, bone-dry, and hotter than at any time in recorded history. Parts of the South-Southeast and the Midwest are experiencing higher than normal precipitation levels. In other words, the West is on fire and the South-Southeast is sinking. As daily reports in America cry out for help due to the climate crisis, government authorities are striving to improve the original form of renewable energy that is currently operating in the country. Hydroelectricity is a big factor in helping the climate crisis in the South-Southeast and anthropogenic systems are rapidly being constructed to overpower the use of fossil fuel emissions. The overall goal is to analyze the trends of drought and heavy precipitation in the United States so that the right renewable resources are consistently available in the area it pertains to. We present here a description of various precipitation levels throughout the United States, and an analysis of the insignificance or importance hydroelectricity has on different areas of the country.

Non-Toxic Renewable Energy Storage via Solar Thermal Decoupled Electrolysis of Iron Oxide

Jackson King | Chemistry | CHEM-4

Widespread adoption of renewable solar energy is currently limited by a lack of long term storage commodities. As a preferred option, fuels satisfy flexible requirements including transportability, high energy density, and in the case of hydrogen, clean combustion. Here we will outline a method of producing hydrogen using an iron oxide-based system, which was selected due to its non-toxicity and relative abundance. First, the iron oxide hematite would be decomposed in a solar furnace, producing oxygen and magnetite. Next, the magnetite is reacted through electrolysis to produce hydrogen gas and regenerate the hematite precursor. Two electrochemical methods of testing this reaction were performed with variable temperature and pH; one with magnetite deposited on steel surfaces, and another with magnetite dissolved in etidronic acid. Finally, the pH of the etidronic acid solution was raised to precipitate the phase pure hematite completing the cycle.

Improving the Synthesis of an Unnatural Fluorescent Amino Acid

Taylor A. Gaskill, Esteban B. Kurth | Chemistry | CHEM-5

The long-term goal of this project is to more efficiently synthesize an unnatural fluorescent amino acid, 3-[7-nitro-2,1,3-benzoxadiazol-4-yl]-L-alanine, diazole for short. This fluorescent amino acid can be incorporated into a transparent protein, thus creating a “glow-in-the-dark” protein. Two parallel pathways are being explored to synthesize this diazole amino acid: traditional organic synthesis and biocatalysis. 1H-NMR and LC-MS are being used to analyze the organic route by monitoring the reaction kinetics of the key coupling reaction. The goal of these kinetics experiments is to identify optimal reaction conditions (solvent, temperature, etc.). For the biocatalytic route, the enzyme glutathione S-transferase from the cyanobacterium T. elongatus is being used to catalyze the key coupling reaction. Enzyme kinetics are monitored using LC-MS.

New Ways of Synthesizing Potential Pterin Anti-Fungal Drugs

Kyle J. Kohlmeyer, Charlie Toman | Chemistry | CHEM-6

Pterin based compounds have shown some promise as potential anti-fungal compounds; however, the low solubility of them in most organic solvents make the synthesis of these compounds tedious and difficult. Work is underway to do some of the steps of the synthesis in a different order to avoid the solubility issues. The goal is to be able to synthesize the final furan intermediate before adding the very insoluble pterin group in the final step to bypass any solubility issues that were encountered in synthesizing this molecule. First, the chlorinated furan intermediate underwent a reaction with sodium azide to convert the chlorine group on the furan into an azide group. Currently, work is being done on the second step, a DBU amidation to convert an ester to an amide group with a BOC protected amine.

How to Become a Billionaire in One Year by Using AWS

Siva Korada | Computing and Information Sciences | CIS-2

The purpose of my paper is to make a small-scale company become a billionaire company by using AWS in one year and to show how it plays a pivotal role in the IT industry. The agenda is to show the critical advantage of distributed computing which is the chance to supplant direct front capital framework costs with low factor costs that scale up the business. I choose this topic because AWS gives a profoundly solid, versatile, minimal expense foundation stage in the cloud that powers a huge number of organizations in 190 nations around the world. In 2006, Amazon Web Services (AWS) started offering IT framework administrations to organizations as web administrations are presently usually known as distributed computing. AWS cloud computing has emerged, and companies started using it which is more efficient and cloud-effective. My research completely went on what are the things, procedures, and types of AWS. I researched different types of AWS services. My analysis and conclusion are that the companies set aside the resources to make investments into progressive development to ensure the growth and future of the company. Having support and resources, allowing the company to grow and have limitless financial globalization achieved by using the AWS Cloud platform as it is a comprehensive cloud services platform that offers compute power, storage, content delivery, and other functionality that organizations can use to deploy applications and services cost-effectively with flexibility, scalability, and reliability.

Impact of operating obstacles on the total annual sales of SME’s in Afghanistan

Muskan Khadka | Computing and Information Sciences | CIS-3

The purpose of this study is to find out the effect of obstacles in the establishment’s total annual sales of small medium enterprises (SME’s). SME’s are the enterprises which are mostly start-ups and have the number of employees and revenue less than threshold. The paper deals with the data from SME’s to study the obstacles in the operating activities which effects the sales. The dataset is taken from the world bank survey of Afghanistan in 2013. The variables selected from the dataset as obstacles are power outages, access to finance, political instability, corruption, telecommunication, transport, customs and trade regulations. Paper uses the regression analysis to analyse the data and provides a relation between the independent and the dependent variable. It further describes the rationale behind the relation between the variables. As expected, when some of the obstacles like corruption, telecommunications and custom and trade regulation are very severe reduces the annual sales because it increases the functional issues of an enterprise. Therefore, this shows a negative relationship between these obstacles and the enterprises total annual sales. Whereas, when the remaining obstacles like power outages, access to finance, political instability and transport are severe, increases the annual sales which is unexpected because it should lead to loss of production. This shows a positive relationship between these obstacles and the enterprise’s total annual sales. The rationale behind it might be the size of an enterprise. It might be so small that obstacles did not affect the total annual sales of an enterprise. There will be more SME’s emerging in fast ratio in the developing countries and hence the study of obstacles becomes more important.

Experimental Characterization of Biological Tissue Mechanics

Nick Evans, Bethany Luke | Mechanical and Bioengineering | MBE-1

The function of ligaments and tendons is to transmit tensile forces, allowing healthy, bodily motion. However, if improper loading is placed on the tissue, the structures may rupture leading to pain, loss of function, and reduced quality of life. To prevent rupture, loads must remain below the ultimate strength of the tissue, but the maximum stress that the tissue can withstand varies due to several factors such as age, sex, body temperature, loading history, hydration state, and strain rate. These factors can be tested in order to understand how they affect tissue failure risk. Therefore, the objective of our research is to design and develop a lab procedure for future students to complete that experimentally characterizes the biological tissue mechanics. Load carrying tissues can be characterized by their stress-strain behavior utilizing a tensile tester. Using the tensile tester, the lab will consist of several experimental tests: freeze thaw cycles, varying strain rates, stress relaxation, and varying hydration. Creating a lab procedure for these experiments will allow students to describe both the viscoelastic properties of the tissue and the influences of strain rate on ultimate stress and ultimate strain. By measuring these quantities, we can gain a better understanding on the factors that affect tissue failure risk allowing for better treatment methods for injured athletes.

Searching for Periodicity in a Sample of Evolved Stars

Sean Egan | Physics and Astronomy | PHYS-4

My research focuses on finding periodicity in the light variations of a sample of proto-planetary nebulae (PPNe). Proto-planetary nebulae are stars late in their evolution, when they are in transition between the red giant and the planetary nebulae phases. These come from stars like the sun. Analysis of data shows that these objects periodically pulsate, and some have been found to have multiple periods to their pulsation. The main goal is to find pulsation periods for these PPNe, in order to better understand their internal properties. This research was overseen by Dr. Bruce Hrivnak. I am studying two different groups of PPNe. The first group of four has shown evidence of long-term, multi-year variations in previous preliminary studies, and we want to do a complete analysis of their light curves to determine both the pulsation periods and the multi-year periods simultaneously. For example, one has a pulsation period of 103 days and a long-term period of ~3.5 years. The second group are new, previously unstudied PPNe. I am using light curve data from the publicly-available All-Sky Automated Survey for Supernovae, and also, in most cases, data obtained at the Valparaiso University Observatory. Analysis is conducted via Period04, a program which searches for periods in a dataset. For those with long-term periodic variations, the cause is likely due to external factors, such as dust or a binary companion. This research is supported by a grant from the Indiana Space Grant Consortium.

2013 Fill Quality Assurance

Brook Burbridge | Physics and Astronomy | PHYS-5

The Solenoidal Tracker at RHIC (STAR) located at Brookhaven National Laboratory uses longitudinally polarized proton-proton collisions to study the gluon contribution to the spin of the proton. Using data from the 2013 longitudinally polarized proton-proton collisions (√s = 510 GeV), the production of neutral pions (π0) from these collisions are studied. The spin-dependent asymmetry of the neutral pion production, (ALL), can be determined by analyzing the photons produced from the π0 decays, as detected in the Endcap Electromagnetic Calorimeter (EEMC). The EEMC, positioned in an intermediate pseudorapidity range of 1 < η < 2, is able to measure the energy and position of the electromagnetic shower from an incoming photon. From these measurements, the two-photon invariant mass spectrum can be reconstructed. This spectrum is then fitted using a skewed Gaussian function to represent the π0 signal and a Chebyshev function to characterize the random two-photon background. Integrating the resulting Gaussian peak will determine the total number of π0s. The π0 ALL is calculated from the number of π0s produced in collisions of protons with different spin alignments. Numerous tests must be made to authenticate the quality of the data being analyzed in this very large data set. The status of this analysis will be presented.

Measuring η ALL with 2012 STAR Endcap Calorimeter Data

Maggie Bliese | Physics and Astronomy | PHYS-5

This research project focused on measuring asymmetry (ALL) of eta (η) particles from products of longitudinally polarized proton-proton collisions (√s = 510 GeV) at the Solenoidal Tracker at RHIC (STAR), located at Brookhaven National Laboratory. The η particles decay into two photons (mean lifetime = 5 × 10-19 s), which are detected by the Encap Electromagnetic Calorimeter (EEMC). The EEMC, positioned at one end of the detector, measures the energy and position of an incoming photon’s electromagnetic shower. From these measurements the two-photon invariant mass spectrum can be reconstructed. These spectra are then fitted using a Gaussian peak and a background polynomial function to determine the total number of η particles (mass = 0.545 GeV) produced by the initial collision. ALL is then calculated from the number of η particles produced in collisions of protons with different spin alignments, and gives information about the gluon contribution to the spin of the proton. The status of the analysis of the 2012 data set to measure the η ALL will be presented.

Seeking the Magnitude of the Gluon Contribution to Proton Spin with STAR Endcap π0s

Nicholas Gilles, Marcus Engstrom | Physics and Astronomy | PHYS-5

The spin of the proton is known to be 1/2 ℏ. It derives from the spin and orbital angular momenta of the proton’s constituents: quarks and gluons. The relative contribution of the various components remains uncertain, with the quark spin contribution significantly lower than once anticipated. We seek to clarify the gluon spin contribution, in particular. At the STAR experiment at Brookhaven National Laboratory (BNL) we observe collisions between spin-polarized beams of protons. In this measurement, our probe of collisions with initial-state gluons will be the neutral pion (π0), abundantly produced in such collisions. The π0s rapidly decay into two photons, which we can detect with STAR’s Endcap Electromagnetic Calorimeter (EEMC). We have been calibrating and reconstructing the 2013 data to form both photon and π0 candidates and storing this information in data structures called trees. The π0’s invariant mass is calculated from the two photons using their energies and opening angle. We will eventually fit the invariant mass spectrum to separate signal and background contributions and calculate the number of π0s produced. With the number of π0s for each spin combination, we will then calculate the ALL, the doubly longitudinal spin asymmetry, for π0 production in the EEMC. We track the reconstruction process and assure its quality. We will describe our efforts to identify bad data using π0 mass distributions and quantities including a calculated signal fraction. We will present the status of the 2013 EEMC π0 dataset and our quality assurance analysis.

Constructing and Testing a High Voltage Chain for the nEDM Experiment at Oak Ridge National Lab

Lauren Kadlec | Physics and Astronomy | PHYS-5

The neutron Electric Dipole Moment (nEDM) experiment at Oak Ridge National Lab aims to search for the nEDM at the level of 3 x 10-28 e*cm using a strong electric field and a small, stable magnetic field. The experiment calls for an electric field of 75 kV/cm, which requires a high voltage chain to be suspended into the apparatus where ultra-cold neutrons will be present. To test the conductive and electrical properties of such a chain, a test on the Half Scale High Voltage system (HSHV) was conducted to see if a stainless steel chain could sustain this electric field without breaking down while suspended in liquid helium at 0.4K and with various sensors in its proximity. The chain’s smoothness, stability, and cleanliness had to be maximized to prevent breakdown. For the final project, stainless steel creates too much fluctuation in the magnetic field. Therefore, unique acrylic diodes coated in copper germanium were tested for their electric capabilities in liquid helium. Details on the voltage chain assembly and tests, along with the copper germanium performance, will be presented.

Photometry and Python: Painting a Picture of Planetary Nebula Central Stars

Olivia Krugman | Physics and Astronomy | PHYS-6

Planetary nebulae are some of nature’s most beautiful yet most mysterious objects. Many of these PNe have intricate shapes not expected to be produced by a spherical star. We want to further understand how their unique shapes are produced, especially those that do not fall within conventional classifications, and thus we must do further research into their physical characteristics. Our research aims to study the effects binary star systems have on PNe. We are able to get in-depth looks into these objects using data collected from the observatories affiliated with the SARA (Southeastern Association for Research in Astronomy) Consortium, of which Valpo is a member institution. We then use photometry, measuring the magnitude (brightness) of an object, to get better measurements of magnitude, temperature, and distance, among other values. While performing photometry is the main part of our research, we have another part of the project designed to make the process easier for users to compare the data. We are working on creating a new Python code that more efficiently takes the resulting large amount of information and parses it into a smaller amount of specific information that we can work with and analyze. The code takes the original images and measures the brightness of each star, allowing us to use these values to arrive at our final brightness measurements. We are improving existing code by adding more efficient Python packages that will further aid in the ease and speed of analyzing the data from these objects.