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MATH2017RABBY15190 MATH

Algebraic Sets, Varieties and Their Multiplicity Structures

Type: Graduate
Author(s): Fazle Rabby Mathematics
Advisor(s): Scott Nollet Mathematics
Location: Session: 1; B0; Table Number: 6

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An algebraic set is the solution set of a system of polynomial equations. A variety is a special type of algebraic set. In the two dimensional Euclidean plane the solution set of the polynomial equation x=0 is nothing but the Y-axis, which is an example of a variety. Historically people studied varieties and their relations very carefully. It turns out that instead of studying varieties individually it is more fruitful to study them in a 'family'. But in this set up degeneracies happen naturally. For example, in the two dimensional Euclidean plane if we take the unit circle centered at the origin and intersect it by the vertical lines x=a, where a is any number from the interval [-1, 1], we always get two distinct points unless a is -1 or 1, i.e., degeneracy happens at -1 and 1. In those two degenerate cases the solution sets consist of just one point, but in the algebraic point of view they come twice. So we can say these algebraic sets have multiplicity 2. It was very difficult to study these multiplicity structures using the classical tools of algebraic geometry. But after Alexander Grothendieck introduced and developed his theory of 'Schemes' in the 1950s , we can study such structures closely and talk about their geometries.

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MATH2017SMITH36813 MATH

Indices of Algebraic Integers in Cubic Fields

Type: Graduate
Author(s): Jeremy Smith Mathematics
Advisor(s): George Gilbert Mathematics
Location: Session: 1; 2nd Floor; Table Number: 1

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An algebraic integer is a complex number that is a root of a monic polynomial with integer coefficients. It is well-known that there is not always a single algebraic integer that can generate the ring of algebraic integers contained in a field extension of the rational numbers. The index of an algebraic integer is a natural number that measures how far a ring of integers is from having such a "primitive element." We investigate these indices in cubic fields and determine which natural numbers occur as indices in given families.

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NTDT2017GENASCI48381 NTDT

Impact of an Educational Campaign on College Students' Food Waste Intentions and Behaviors

Type: Undergraduate
Author(s): Annie Kate Genasci Nutritional Sciences Chandler Dalton Nutritional Sciences
Advisor(s): Gina Jarman Hill Nutritional Sciences
Location: Session: 2; 3rd Floor; Table Number: 2

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Background: Approximately 40% of food produced in the U.S. is wasted. Consumers are responsible for the largest portion of food waste. The average college student generates ~142 pounds of food waste/year. The purposes of this research were to measure the impact of an educational food waste campaign on 1) actual food waste behaviors on a college campus and 2) students’ knowledge, beliefs, perception of referent others and social acceptability, attitude, subjective norm and intensions related to food waste.
Methods: An electronic food waste survey was developed. The Institutional Review Board approved this study. Food waste volume was measured by food service employees at breakfast for five days both before and after a food waste educational campaign. A convenience sample of participants provided consent prior to survey completion before and after the educational campaign. Data were coded into and analyzed using SPSS 24.
Results: Breakfast food waste totaled 610 quarts for the 7226 people served in ten days. Food waste per person was not significantly different pre/post-campaign. Approximately 0.076 and 0.10 quarts of breakfast food waste per person were measured pre/post-campaign respectively. Participants completed pre- (N=86) and post-campaign surveys (N=78). Total knowledge scores did not significantly change following the educational campaign. Knowledge regarding dating labels improved significantly (p<0.001). About 56% (N=47) and ~49% (N=38) participants reported often throwing away food from their refrigerators or pantries because use-by or sell-by dates had passed on pre/post-campaign surveys, respectively.
Discussion: Participants reported positive intentions to avoid food waste on both pre/post-campaign surveys. Knowledge regarding food waste remained low following the educational campaign. Additionally, almost two-thirds of participants did not agree that most people think food waste is a problem.

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NTDT2017KEATLEY5079 NTDT

Relationship Between Water Consumption & Overall Skin Health in Individuals 18-24 Years of Age

Type: Undergraduate
Author(s): Katie Keatley Nutritional Sciences Vivian Castillo Nutritional Sciences Ashley Peek Nutritional Sciences
Advisor(s): Rebecca Dority Nutritional Sciences
Location: Session: 2; 3rd Floor; Table Number: 8

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Background: Water is an essential component of the skin cells. Research suggests that lack of proper hydration causes skin to become dry, tight, and less resilient. A recent study showed that an increase in water intake has a positive correlation with skin appearance, especially in those who had inadequate water intake to begin with. However, opposing research studies have found that there are too many external factors to glorify water intake as the main contributor to skin appearance.

Purpose/Objective: To determine the effects of water consumption on skin complexion.

Methods: An online survey, regarding skin type, skin care processes, medications, physical activity, and fluid and dietary intake, was developed to evaluate the relationship between water intake and skin health. Researchers recruited Texas Christian University student participants using email and social media. Once the survey sample of 105 participants was met, data was analyzed using SPSS.

Results: Upon surveying participants (N=105), there were strong correlations (p<0.01), between skin type and fruit servings, skin type and yogurt consumption, and skin type and alcohol intake. There was also a strong correlation (p<0.01) among those who consumed water and additional healthy habits, such as higher fruit, vegetable, and yogurt consumption, and higher amounts of moderate or vigorous exercise. Approximately 24% (n=25) of the respondents mentioned that their skin appearance changes due to many factors including weather, medications, stress, dehydration, makeup, or menstrual cycle. There were no significant relationships between water intake and skin satisfaction or water intake and acne.

Conclusions: While water provides many benefits, other factors likely contribute to optimum skin health. Those who reported drinking more water had healthier habits overall, including exercising and consuming fruits, vegetables, and yogurt, which implies that further assessment is needed to determine which of these factors impact skin appearance and satisfaction.

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NTDT2017KNUDSEN54486 NTDT

Female Menstrual Cycle and Chocolate Cravings in College-Aged Health Professions Women

Type: Undergraduate
Author(s): Molly Knudsen Nutritional Sciences Anna Schwartz Nutritional Sciences
Advisor(s): Lyn Dart Nutritional Sciences Meena Shah Interdisciplinary Jada Stevenson Nutritional Sciences
Location: Session: 1; 2nd Floor; Table Number: 2

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Background: Research has shown that significant food cravings, as well as increased caloric intake, occur during the menstrual cycle. Chocolate has been shown to be one of the most craved foods by women, and tends to be higher in women aged 18-35 compared to women who are post-menopausal. The purpose of this study was to determine if there is a relationship between the stage of the female menstrual cycle and chocolate cravings in college-aged health professions women.

Methods/Study Design: Two-hundred and eleven college-age health profession females participated in this study. Participants responded to an electronic survey, with questions about demographic and lifestyle practices, regularity and stages of their menstrual cycle, knowledge relating to chocolate cravings during menses, and personal beliefs and practices associated with chocolate cravings in general. Recruitment procedures included campus-wide emails, flyers, department student meetings, and announcements. Study procedures were approved by Texas Christian University IRB, and participants’ informed consent was obtained. Data was analyzed to meet study objectives (SPSS, p<0.05).

Results: Results show more than three-fourths of all participants felt they were “knowledgeable/somewhat knowledgeable” about the relationship between the menses cycle and increased chocolate cravings (79%), “believed/somewhat believed” chocolate cravings increase with the menstrual cycle (82%), and knew of a family member or friend with increased chocolate cravings during their cycle (78%). Approximately one-third of participants experienced chocolate cravings just prior to, as well as during, their menstrual cycle; whereas, another third of the respondents reported chocolate cravings only sometimes during these same stages of the menses.

Conclusions: Findings suggest female health professions students are aware of chocolate cravings associated with the menstrual cycle, both from personal experience and information shared by others. As future health practitioners, this knowledge can help their patients/clients understand more about changing eating practices and craving tendencies during the menstrual cycle.

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NTDT2017LANE60408 NTDT

The Correlation Between the Addition of a Condiment and Plate Waste in an Elementary School Meal Program Serving Students Ages 5-12

Type: Undergraduate
Author(s): Samantha Lane Nutritional Sciences Sarah Timmer Nutritional Sciences
Advisor(s): Rebecca Dority Nutritional Sciences
Location: Session: 1; 3rd Floor; Table Number: 4

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Background: There have been many food waste studies done in elementary schools around the country. Several studies have determined that main entrées contribute significantly to plate waste in elementary school food programs, but studies relating the use of condiments and their influence on food waste need further exploration.
Objectives: Determine the correlation between the addition of condiments and the amount of plate waste from a chicken entrée.
Methods: In Phase I, data was collected in an elementary afterschool meal program. Researchers evaluated plate waste for the chicken entrée once a week for a total of four weeks. Chicken entrée plate waste was evaluated by weight and visual assessment. The waste weight was compared to the weight of one serving of the chicken entrée. A photograph of the total plate waste was taken each week for visual comparison. Researchers compared the total number of servings prepared to the number of servings leftover. In Phase II of the study a condiment (ketchup) was added to the menu when the chicken entrée was served. A marketing campaign was implemented with flyers to advertise the addition of the condiment. For the remaining four weeks, plate waste was documented using the same methods utilized during Phase I.
Results: In Phase I, an average of 26.7% of chicken entrées was wasted. In Phase II, an average of 20.8% of chicken entrées was wasted. No statistically significant difference was found in the percentage of food leftover between Phase I and Phase II (p<0.06). After adjusting for differences in initial portion size, there was still no statistically significant difference in weight of entrée left over (p<0.3).
Conclusion: Though there was no significant difference, the amount of waste is large enough to draw attention to the problem of waste in school foodservice. More research is necessary to determine what factors are leading to food waste.

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NTDT2017LOPEZ5279 NTDT

An Analysis of Metabolic Feedback to High-Fat Meals of Assorted Fatty Acid Composition

Type: Undergraduate
Author(s): MiguelAngel Lopez Nutritional Sciences Danielle Rivera Nutritional Sciences
Advisor(s): Jada Stevenson Nutritional Sciences
Location: Session: 2; 1st Floor; Table Number: 6

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An Analysis of Metabolic Feedback to High-Fat Meals of Assorted Fatty Acid Composition
M.A. Lopez1, D.B. Rivera1, J.L. Stevenson, PhD, RDN, LD1
1Texas Christian University, Fort Worth, TX

Background: There are many factors associated with obesity, including consuming a high-fat (HF) diet. The amount and type of dietary fatty acids (monounsaturated fatty acids, MUFAs; polyunsaturated fatty acids, PUFAs; saturated fatty acids, SFAs) in the diet give rise to physiological differences in terms of their effects on whole-body metabolism.

Methods: Three normal weight, premenopausal women (BMI: 18.5-24.9kg/m2), aged 18-40 years, participated in a randomized, single-blind, crossover study in which they consumed three HF meals (70% of energy) rich in either MUFAs, PUFAs, or SFAs. Participants completed a screening visit followed by three visits (one for each HF treatment). Following a one-day lead-in diet, participants arrived at the Obesity Prevention Lab in a fasted state where anthropometrics and resting metabolic rate were recorded. Participants then consumed the HF treatment. Indirect calorimetry was used to measure respiratory gases for a 3-hour postprandial period. Data collected was used to determine respiratory exchange ratio (RER) for assessing RER, energy expenditure, and substrate oxidation.

Results: No treatment differences were found for postprandial RER (MUFA: 0.82±0.01; PUFA: 0.81±0.01; SFA: 0.81±0.01) or for postprandial EE (MUFA: 16.54±0.58kcals; PUFA: 17.06±1.46 kcals; SFA: 16.57±0.67kcals). No treatment differences were found for postprandial fat oxidation 1.03±0.11, 1.11±0.09, and 1.10±0.09g or for carbohydrate oxidation 1.81±0.16g, 1.73±0.18g, and 1.63±0.09g following MUFA, PUFA, and SFA-rich HF meals, respectively.

Conclusions: In premenopausal, normal weight women, HF meals rich in either MUFAs, PUFAs, or SFAs did not differentially affect postprandial RER, EE, or substrate oxidation.

Funding Source: TCU SERC Grant # 150321

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NTDT2017RIVERA1167 NTDT

Composition of High-Fat Meals Did Not Affect Postprandial Subjective Measures of Hunger and Satiety nor Subsequent Intake at the Next Meal

Type: Undergraduate
Author(s): Danielle Rivera Nutritional Sciences Miguel Angel Lopez Nutritional Sciences
Advisor(s): Jada Stevenson Nutritional Sciences
Location: Session: 2; 2nd Floor; Table Number: 6

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Composition of High-Fat Meals Did Not Affect Postprandial Subjective Measures of Hunger and Satiety nor Subsequent Intake at the Next Meal
D. B. Rivera, 1 M. A. Lopez1, J. L.Stevenson, PhD, RDN, LD1
1Texas Christian University, Fort Worth, TX

Background: Dietary fat in meals can aid in overall satiety, however there is still more research needed to understand the varying effect of saturation of fatty acids on satiety. This study will look at the degree of satiety seen in participants who consume high fat meals consisting of either monounsaturated fats (MUFAs), polyunsaturated fats (PUFAs), and saturated fats (SFAs).

Methods: Three, normal weight (18.5-24.9) women aged (18-40y) participated in this randomized, single-blind, crossover study. Participants completed three study visits to complete all three treatment conditions (three HF meals [70% of energy] rich in MUFAs, PUFAs, or SFAs). At each visit, anthropometrics, height, weight, fasting blood glucose, body fat percentage, blood pressure, waist and hip circumference were collected. Participants then consumed one of the three HF meals. Visual analog scales (VAS) were administered every 30min for 3h to record feelings of hunger, fullness and satiety at fasting and post prandial. An ad libitum buffet lunch was provided 3h after the HF meal.

Results: There was a significant main effect for time for hunger (p<0.05), fullness (p<0.05), and how much food the participant thought they could eat (p<0.05), yet no significant treatment effects (ns). Further, there were no differences in 3hr postprandial averages between treatments. Lastly, there were no differences in consumption at the ad libitum meal between treatments.

Conclusions: In premenopausal, normal weight women, HF meals rich in either MUFAs, PUFAs, or SFAs did not differentially affect postprandial VAS measures or ad libitum intake at their next meal.

Funding Source:
TCU SERC Grant # 150321

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NTDT2017SETTLE5565 NTDT

Determination of the Impact of a Culinary Medicine Nutrition Education Program on Dietary Behaviors, Meal Preparation, and Nutritional Knowledge of Cancer Survivors

Type: Undergraduate
Author(s): Maddie Settle Nutritional Sciences Maeson Wampler Nutritional Sciences
Advisor(s): Gina Hill Nutritional Sciences
Location: Session: 2; 3rd Floor; Table Number: 4

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Background:
A healthy diet and physical activity can help manage weight and reduce the risk of cancer recurrence. Research reveals that cancer survivors want information regarding cancer therapy side effect management and how to consume a balanced diet. According to previous research, nutrition education should improve nutrition knowledge, quality of life, confidence, and motivation to make positive lifestyle changes. The purpose of this study was to assess the impact of a six-week culinary medicine nutrition education program on nutritional knowledge, motivation to make lifestyle changes, and self-efficacy of cancer survivors.

Methods:
Participants provided informed consent prior to completing initial and final surveys evaluating nutritional history, dietary and physical activity behaviors, and nutrition knowledge. Data were coded and analyzed using SPSS 24.

Results:
Participants (N = 21) were 56.8+/-9.9 years of age. Although no significant difference was detected between initial and final nutrition knowledge scores, participants’ confidence scores preparing meals improved significantly from 0.89 to 1.56 (p≤0.05). Participants reported a significant increase in daily vegetable intake from 1.73 to 2.63 servings/day (p≤0.05).

Conclusion:
The lack of improvement in average knowledge scores could be attributed to inconsistent participant attendance throughout the six-week course and survey knowledge questions that did not focus on topics discussed in-depth during the course. The demonstration and hands-on cooking portion of the course positively impacted participants’ confidence and motivation to make healthy changes. Meal preparation confidence increased significantly with all participants stating they agreed/strongly agreed in feeling confident preparing meals in the final survey. Almost 100% of participants reported that they intend to make dietary changes and 100% would implement what they learned in the class into their lives. Study limitations include a small sample size and frequently skipped survey questions. Further research is needed to determine best practices to improve nutrition knowledge for cancer survivors in this setting.

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NTDT2017SIMONS51957 NTDT

EXAMINATION OF PORTION SIZES OF REGULAR CHEESE PIZZAS FROM A VARIETY OF CASUAL RESTAURANTS IN FORT WORTH, TX

Type: Undergraduate
Author(s): Melissa Simons Nutritional Sciences Jaclynn Clay Nutritional Sciences Grace Niestrom Nutritional Sciences Erin Owen Nutritional Sciences
Advisor(s): Anne Vanbeber Nutritional Sciences Lyn Dart Nutritional Sciences
Location: Session: 1; 3rd Floor; Table Number: 7

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Learning Outcome: To examine differences in pizza portion sizes based on variations and lack of standardization of total weight, diameter, and individual slices.

Background: Supersized food portions were introduced in the U.S. during the 1970s. Since then the obesity epidemic has spiked, suggesting larger portion sizes and prevalence of obesity may be related. Because of this trend in larger portion sizes, experts agree that many people tend to overestimate the appropriate amount of food they should consume. The purpose of this study was to examine and compare pizza portion sizes from different local establishments.

Study Design: Nine large cheese pizzas and five personal size cheese pizzas were purchased from various restaurants in Fort Worth, Texas. Pizzerias were selected based on customer reviews designated by Yelp.com ratings, including five pizzerias with high ratings, four pizzerias with average ratings, and five pizzerias with low ratings. Pizza measurements were recorded for total weight, diameter, weight of the largest and smallest slices, and total cost of each pizza. Data was analyzed to meet study objectives (SPSS, P<0.05).

Results: A wide variance in recorded measures and lack of standardization was noted among the nine large size pizzas, including total weight (458-1585 gm), diameter (12.8-17.5 in), weight of largest slice (54-266 gm), weight of smallest slice (20-116 gm), and total cost of the pizza ($10.81-$19.47). Except for a smaller variance in total weight (204-380 gm), the five personal-size pizzas showed similar wide differences in diameter (6.25-12.25 in) and total cost ($4.33-$11.91). Total weight, diameter, and cost were also correlated positively in both the personal-size and large pizzas. In contrast to large size pizzas, personal-size pizzas showed a positive correlation between pizza diameter and low-to-high customer review ratings.

Conclusions: Results suggest a lack of standardized portion sizes among different large size and personal size pizzas. Posting calories and other nutrient information about pizza portion sizes can fill a critical information gap and help consumers make informed and healthful dietary choices.

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NTDT2017ZEAGLER45789 NTDT

Examination of Trends in Coconut Oil Consumption and How this Impacts Product Merchandising in Area Grocery Stores

Type: Undergraduate
Author(s): Gabriela Zeagler Nutritional Sciences Tara Martinez Nutritional Sciences
Advisor(s): Rebecca Dority Nutritional Sciences
Location: Session: 1; 3rd Floor; Table Number: 9

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Background: Recent research indicates that coconut oil consumption has increased in popularity due to a variety of perceived health benefits. Although the actual health benefits of coconut oil continue to be a topic of controversy, sales of the oil have increased radically. Product shelf placement has been shown to impact grocery item sales, with many sellers placing popular or desired products at eye level to attract buyers.

Objective: The objective of this study was to determine if the increased popularity of coconut oil impacts price and grocery store shelving placement relative to other popular oils.

Design and Methods: Researchers selected 6 different local grocery stores that varied in type of market, target population, and geographic location. Data was collected for 4 popular oils: coconut, olive, canola, and vegetable. At each store, researchers documented the total number of brands for each of the four oils, their individual price per fluid ounce, and whether the oil was placed above eye level, at eye level, or below eye level. Photos were taken of each of the shelving units. Data was analyzed using Microsoft Excel.

Results: There was no statistical correlation between type of oil with shelving location nor with price per ounce and shelving location. There was a statistically significant difference (p<0.05) between the average price of coconut oil compared to canola and vegetable oils. Four out of the six stores included in the study had a moderate to high positive correlation between price per ounce and the percentage of each type of oil carried in the store.

Conclusions: Researchers noted trends related to higher price per ounce, eye level shelf placement, and increased amount of advertisements for coconut oil. There was a statistically significant difference between the average price per ounce of coconut oil compared to canola and vegetable oils, which supports the observations made. However, it is believed that there was no statistical correlation between the price per ounce, or type of oil, with shelving location since some of the stores had large oil selections that required placement of oils across multiple shelves. Additionally, stores appeared to have placed oils on different shelves depending on their target market of shoppers. Stores with a lower income target population placed coconut oil on the top shelves and carried less of the product, overall. Stores with a higher income target population placed coconut oil at eye level, had increased amount of the oil in stock, and had advertisements for the oil located on the shelving unit. Future research on the subject should limit location selections to one target market to eliminate this variable.

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PHYS2017ANTWIDANSO37077 PHYS

Feeding the Milky Way: Optical Observations of the Leading Arm

Type: Undergraduate
Author(s): Jacqueline Antwi-Danso Physics & Astronomy
Advisor(s): Kat Barger Physics & Astronomy
Location: Session: 2; 3rd Floor; Table Number: 6

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The nearby Magellanic Cloud galaxies are tidally interacting with each other, displacing over 2 billion times the mass of the Sun in gas. A tidal feature called the Leading Arm is spearheading these galaxies on their trajectory to the Milky Way. Its fragmented morphology suggests that it is already interacting with our galaxy and supplying it with star-forming material in the form of gas. We present new optical observations of the Leading Arm with which we derive a heliocentric distance to the structure.

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PHYS2017CIAMPA7324 PHYS

Supernovae in Large Magellanic Cloud Drive Massive Winds Toward Milky Way Galaxy

Type: Graduate
Author(s): Drew Ciampa Physics & Astronomy
Advisor(s): Kat Barger Physics & Astronomy
Location: Session: 2; B0; Table Number: 1

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Located inside the Large Magellanic Cloud, fierce explosions called supernovae have thrown out massive amounts of gas in every direction. A portion of this gas is aimed toward the Milky Way and is on a crash course with our galaxy. We are observing this gas with the Wisconsin H-Alpha Mapper, which provides a window into how the gas is distributed. These observations show two periods of supernovae explosions that created two distinct gas winds. One of these winds is currently active while the other was produced roughly 300 Million years old. Studying these gas clouds will provide information on how massive these winds are and the rate at which they are produced. The ejected gas is headed toward the Milky Way could supply our galaxy with additional gas to form stars in the future.

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PHYS2017DOAN39551 PHYS

Effect of microviscosity and pH on solvatochromic dye LDS 798

Type: Graduate
Author(s): Hung Doan Physics & Astronomy
Advisor(s): Zygmunt Gryczynski Physics & Astronomy
Location: Session: 2; 2nd Floor; Table Number: 4

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The unexplored effect of viscosity, temperature, and pH on the twisted intramolecular charge transfer (TICT) fluorescence of Styryl-11 (or LDS 789) have been studied. We investigate LDS 798 fluorescence spectroscopic properties including absorption, emission and fluorescence lifetime in various viscosities, pHs, and temperatures. We found LDS 789 fluorescence responds to different viscosities with a five-fold increase in total intensity, a slightly blue-shifted in peak intensity, a five-fold change in fluorescence quantum yield, and a five-fold change in fluorescence lifetime going from ethanol to glycerol. LDS 798 in pH solutions shows the existent of two distinct absorption species. One of which absorbs at 400 nm in acidic condition and the other absorbs at 500 nm in basic condition. The two species equilibrate at an isosbestic point of pH 4.3. In glycerol, as temperature changes from 10 C to 70 C, LDS 798 shows a 10x decrease in fluorescence intensity, 20 nm red-shifted fluorescence peak intensity, and a 4.5x decrease in fluorescence lifetime. While in ethanol, the changes are not significant as the temperature goes from 10 C to 50 C with a 2x decrease in fluorescence lifetime and almost no change in fluorescence intensity.

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PHYS2017DONOR10944 PHYS

Solving the Galaxy with BIG DATA

Type: Graduate
Author(s): John Donor Physics & Astronomy Matthew Melendez Physics & Astronomy Julia O'Connell Physics & Astronomy
Advisor(s): Peter Frinchaboy Physics & Astronomy
Location: Session: 1; 1st Floor; Table Number: 5

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Studying something as large as the Milky Way can be a daunting task, and studying the galaxy in its entirety is impossible, so astronomers use small pieces, such as star clusters, to “trace" the behavior and make-up of the galaxy. With the advent of large-scale surveys covering 70%-100% of the sky, more of these tracer components are available than ever before. But they aren’t trivial to pick out of the massive datasets. We have developed a program that integrates data from multiple large scale surveys to identify star clusters and determine fundamental parameters that trace the galaxy in that location (3D velocity and location, chemical make-up, age). We also present initial work using these clusters to study the distribution of chemicals in the Milky Way.

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PHYS2017HASAN32286 PHYS

Tuning the Optical Band Gap of Graphene Oxide by Ozone Treatment

Type: Graduate
Author(s): Md Tanvir Hasan Physics & Astronomy Roberto Gonzalez-Rodriguez Chemistry & Biochemistry Anton Naumov Physics & Astronomy Conor Ryan Physics & Astronomy Brian Senger Physics & Astronomy
Advisor(s): Anton Naumov Physics & Astronomy
Location: Session: 2; 2nd Floor; Table Number: 5

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Graphene oxide (GO) inherits high transparency, substantial conductivity, high tensile strength from its parent materials graphene. Apart from these properties, it emits fluorescence which makes it a potential material to use in optoelectronics and bio-sensing applications. In this work, we have utilized systematic ozone treatment to alter the optical band gap of single-layered graphene oxide in aqueous suspensions. Due to controlled ozonation, additional functionalization takes place in GO graphitic sheet which changes GO electronic structure. This is confirmed by the increase in vibrational transitions of a number of oxygen-containing functional groups with treatment and the appearance of the prominent carboxylic group feature at c.a. 1700 1/cm. Albeit, timed ozone induction introduces only slight change in color and absorption spectra of GO samples, the emission spectra show a gradual increase in intensity with a significant blue shift up to 100 nm from deep red to green. This large blue shift suggests an increase in optical band gap with additional functionalization introduced by ozone treatment. We utilize a semi-empirical theoretical approach to describe the effects of functionalization-induced changes. This model attributes the origins of fluorescence emission to the quantum confined sp² carbon islands in GO encircled by the functional groups. As we decrease the graphitic carbon cluster size on the GO sheet, the optical bandgap calculated via HyperChem molecular modeling increases, which supports the experimentally observed blue shifts in emission. This theoretical result is further supported by the TEM measurement of ozone-treated samples, which shows a decreasing trend of average ordered graphitic carbon cluster size on GO sheets with treatment time. Theoretical modeling, as well as the experimental results, indicate that the optical bandgap and emission intensity of GO are alterable with controlled ozone treatment, which allows tailoring the optical properties of GO for specific applications in optoelectronics and bio-sensing.

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PHYS2017HERNANDEZ54875 PHYS

The rise of ionized gas in the Magellanic Stream

Type: Undergraduate
Author(s): Michael Hernandez Physics & Astronomy
Advisor(s): Kat Barger Physics & Astronomy
Location: Session: 1; 3rd Floor; Table Number: 1

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Two small galaxies outside the Milky Way, called the Magellanic Clouds, are violently interacting with each other. As they interact, gas is stripped out of them, which leaves a huge gaseous tail as they orbit the Milky Way. This tidal debris covers a quarter the sky from earths perspective. The goal of this to project determine the properties of the gas that is trailing behind the Magellanic Clouds by creating maps of the neutral and ionized gas. We trace the neutral hydrogen with radio observations taken with the Arecibo Observatory and the ionized hydrogen using optical observations taken with the Wisconsin H-alpha Mapper telescope. This gaseous stream will one day fall onto the Milky Way and provide our galaxy with material to create new stars.

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PHYS2017HUEYYOU26873 PHYS

Gas motions within the Complex A gas cloud reveal that it is dissolving into as it approaches the Milky Way

Type: Undergraduate
Author(s): Cannan Huey-You Physics & Astronomy Kat Barger Physics & Astronomy
Advisor(s): Kat Barger Physics & Astronomy
Location: Session: 2; 3rd Floor; Table Number: 5

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A massive gas cloud, known as Complex A, is headed towards our Galaxy. This high-velocity cloud is made up of 2 million times the mass of the Sun of neutral and ionized hydrogen. This cloud is traveling towards the Milky Way's disk, through the Galactic halo. This halo is made up of low density gas at a million degrees Kelvin that acts as a headwind that damages the cloud. Light escaping the Milky Way’s disk also hits the cloud and ionizes it. Using 21-cm radio observations from the Green Bank Telescope, we studied the motions of the gas. We found that diffuse gas is lagging behind the denser parts of the cloud. These motions suggest that gas is being stripped off the cloud and that it is dissolving into the Galactic halo. This disruptive process means that less gas will safely reach the disk of Milky Way and therefore the cloud will provide less gas for making future stars.

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PHYS2017HUEYYOU28800 PHYS

In Search of Elusive Complex Eigenvalues to the Schrödinger Equation using Numerical Techniques

Type: Undergraduate
Author(s): Carson Huey-You Physics & Astronomy Magnus Rittby Physics & Astronomy
Advisor(s): Magnus Rittby Physics & Astronomy
Location: Session: 2; 1st Floor; Table Number: 1

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Resonances occurring in quantum mechanical cross-sections can be attributed to the existence of complex eigenvalues of the associated Schrödinger equation. For sufficiently narrow resonances the real part of such eigenvalues corresponds to the energy of the resonance and the imaginary part is directly related to its width.

Recently, mathematicians settled a more than 30-year-old controversy regarding the distribution of such resonance eigenvalues for a specific model scattering potential. The controversy arose due to the fact that two different numerical approaches applied to solving the non-relativistic Schrödinger equation gave rise to two different results. In addition to providing a mathematical proof as to which of the two methods was correct, the recent study predicted the approximate location of additional resonance eigenvalues in the complex energy plane.

The present study seeks to revisit this problem in an attempt to provide more accurate eigenvalues for these additional resonances. The complex rotation method was applied to the Riccati equation corresponding to the one-dimensional Schrödinger equation and a Python code was written to numerically integrate the logarithmic derivative of the wave function and search for energy eigenvalues in the complex plane.

We use 3D plots and short videos to illustrate our technique, the original controversy, as well as the reason for the difficulty in locating the new resonances. Much improved numerical values for these resonances are also presented.

(Poster is private)

PHYS2017JAAFARI42623 PHYS

Characterization of Triazine-based BODIPY Rotor and Non-Rotor Trimers

Type: Undergraduate
Author(s): Hana Jaafari Physics & Astronomy Marlius Castillo Chemistry & Biochemistry Hung Doan Physics & Astronomy Rafal Fudala Interdisciplinary Zhangatay Nurekeyev Physics & Astronomy Sangram Raut Physics & Astronomy
Advisor(s): Zygmunt Gryczynski Physics & Astronomy Sergei Dzyuba Chemistry & Biochemistry
Location: Session: 2; 2nd Floor; Table Number: 2

poster location

Medical diagnostics and therapeutics is an ever-growing field seeking to improve patients’ livelihoods through means of faster, better diagnostic tools and efficient drug delivery platforms. Many intracellular properties such as viscosity that are difficult to measure accurately have been receiving increased attention in recent years. The micro-viscosities within a cell have been reported to be different for normal body cells and cancerous cell. This findings led to development of efforts to develop tools and methods to measure intracellular viscosities using variety of different methods. Herein, we show that Bodipy Trimer; a fluorescent molecular rotor can be utilized to do the aforementioned job. The BODIPY dye is utilized as a molecular viscometer and past spectroscopic and lifetime studies have characterized BODIPY monomers, as well as rotor and non-rotor BODIPY dimers. Triazine-based rotor and non-rotor BODIPY trimers were synthesized for this study, and then the dyes’ photophysical properties and behavior within cells were measured. The results of this study indicated that the BODIPY trimer is a fluorophore with a high molar extinction coefficient, and may be employed as a molecular viscometer within cells.

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PHYS2017MELENDEZ16706 PHYS

The Open Cluster Chemical Abundances and Mapping (OCCAM) Survey: Optical Extension for Neutron Capture Elements

Type: Graduate
Author(s): Matthew Melendez Physics & Astronomy John Donor Physics & Astronomy Peter Frinchaboy Physics & Astronomy Julia O'Connell Physics & Astronomy
Advisor(s): Peter Frinchaboy Physics & Astronomy
Location: Session: 1; 2nd Floor; Table Number: 1

poster location

The Open Cluster Chemical Abundances and Mapping (OCCAM) survey is a systematic survey of Galactic open clusters using data primarily from the SDSS-III/APOGEE-1 survey. However, neutron capture elements are limited in the IR region covered by APOGEE. In an effort to fully study detailed Galactic chemical evolution, we are conducting a high resolution (R~60,000) spectroscopic abundance analysis of neutron capture elements for OCCAM clusters in the optical regime to complement the APOGEE results. As part of this effort, we present Ba II, La II, Ce II and Eu II results for a few open clusters without previous abundance measurements using data obtained at McDonald Observatory with the 2.1 m Otto Struve telescope and Sandiford Echelle Spectrograph.

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PHYS2017MURPHY57326 PHYS

Characterizing Efficacy of Doxorubicin in Breast Cancer Treatment

Type: Graduate
Author(s): Hope Murphy Physics & Astronomy Elizabeth Sizemore Physics & Astronomy
Advisor(s): Hana Dobrovolny Physics & Astronomy Anton Naumov Physics & Astronomy
Location: Session: 1; 1st Floor; Table Number: 7

poster location

Three million women have breast cancer in US, causing breast cancer to be the second most common cause of death from cancer for women. Doxorubicin is a commonly used drug for cancer treatment. The focus of my research is characterizing the drug efficacy for doxorubicin in the human breast cancer cell line MCF-7. There are two quantities that characterize the effect of a drug: E_max is the maximum possible effect from a drug and IC_50 is the drug concentration where the effect diminishes by half. We are using mathematical modeling to extract E_max and IC_50 for Doxorubicin in MCF-7 cells. This work is intended to characterize the efficacy of anticancer drug treatments and determine the correct doses before trying those in patients to get the most effective therapeutic treatment for patients.

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PHYS2017NUREKEYEV64255 PHYS

BSA Induced Fluorescence Enhancement of BODIPY Dimer

Type: Graduate
Author(s): Zhangatay Nurekeyev Physics & Astronomy Micheline Bejjani Physics & Astronomy Sangram Raut Biology
Advisor(s): Zygmunt Gryczynski Physics & Astronomy
Location: Session: 1; 1st Floor; Table Number: 2

poster location

Interaction of protein with environment plays a significant role in proper functioning of a human body. For example, misfolding of a protein leads to severe diseases like cystic fibrosis, Kuru disease, sickle cell anemia etc. One of the major methods in studying of such interactions is Protein Induced Fluorescence Enhancement (PIFE). In this method we utilize a fluorescent dye called boron-dipyrromethene dimer (BODIPY dimer) that binds to the Bovine Serum Albumin (BSA) protein. Then spectroscopic techniques are applied to study this binding complex. We used steady-state and time-resolved fluorescence techniques. It was observed that emission intensity dramatically increases after binding of BODIPY to BSA. It occurs due to Twisted Intramolecular Charge Transfer (TITC) of BODIPY. Forster Resonance Energy Transfer (FRET) from Tryptophan (which is in BSA) to BODIPY was observed.

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PHYS2017OCONNELL18656 PHYS

The Open Cluster Chemical Abundances and Mapping (OCCAM) Survey: Galactic Neutron Capture Elements

Type: Graduate
Author(s): Julia O'Connell Physics & Astronomy Peter Frinchaboy Physics & Astronomy
Advisor(s): Peter Frinchaboy Physics & Astronomy
Location: Session: 2; 1st Floor; Table Number: 5

poster location

The evolution of elements, as a function or age, throughout the Milky Way disk provides a key constraint for galaxy evolution models. In an effort to provide these constraints, we have conducted an investigation into the r- and s- process elemental abundances for a large sample of open clusters as part of an optical follow-up to the SDSS-III/APOGEE-1 survey. Stars were identified as cluster members by the Open Cluster Chemical Abundance & Mapping (OCCAM) survey, which culls member candidates by radial velocity, metallicity and proper motion from the observed APOGEE sample. To obtain data for neutron capture elements in these clusters, we conducted a long-term observing campaign covering three years (2013-2016) using the McDonald Observatory Otto Struve 2.1-m telescope and Sandiford Cass Echelle Spectrograph (R ~ 60,000). We present Galactic neutron capture abundance gradients using 20+ clusters within 6 kpc of the Sun, covering a range of ages from ~80 Myr to ~10 Gyr .

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PHYS2017PAZ5680 PHYS

Optical Properties of Graphene Oxide

Type: Undergraduate
Author(s): Thomas Paz Physics & Astronomy Conor Ryan Physics & Astronomy
Advisor(s): Anton Naumov Physics & Astronomy
Location: Session: 2; 3rd Floor; Table Number: 8

poster location

Graphene is thought to be revolutionary material due to its vast inherent properties. It can give us thinner, faster, and cheaper electronics. Graphene oxide (GO) inherits its properties from graphene and as opposed to graphene, can be conveniently mass- produced using chemical synthesis. We seek to classify new derivatives of graphene with specific optical properties for applications in optoelectronics. The properties of graphene can be tailored through chemical modifications, such as hydrogenation and halogenation.
In this work we present various methods for the synthesis of graphene derivatives by utilizing different functional groups and study their optical properties. The successfully functionalized graphitic derivatives include diazonium functionalized graphene; lightly oxidized graphene; nitro-graphene; and bromo-graphene. The presence of functional groups is confirmed by FTIR spectra showing characteristic vibrational frequencies. All of functionalized graphitic derivatives exhibit fluorescence regarding their functionalization. This leads us to understand that the fluorescence in GO appears not to be dependent on specific functional groups but rather on the confinement of the graphitic regions produced by those.
Such functional derivatives of graphene may expand its applications in optoelectronics and make it a more versatile material for a variety of applications.
Thus we also look into the behavior of graphene oxide in applications related to microelectronics studying the fluorescence of GO in the electric fields.
Emission quenching was observed using GO films under electric fields of the order of 10^6 V/m. A dried GO/PVP film was subject up to 1500V in between transparent conductive ITO electrodes. As high voltage was applied to the slides, a fluorescence signal decreased by 35.9%.
A capability of such electric-field controlled emission is highly applicable in optoelectronic transistors and can advance modern microelectronics.

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