Connect The Department of Mathematics Newsletter

2020- Issue 6

Faculty Festivities

New Faculty Student Activities Math Awareness Month

Friday Seminars

Student Award Winners 1

Connect The Department of Mathematics Newsletter

ISSUE 6 | 2020 The Official Newsletter of the Department of Mathematics Texas State University Chair Susan Morey Associate Chair Jian Shen Assistant Chair Alex White Editor Theresa Jones Contributors: Jayme Blaschke Hailey King Joanna Gutt-Lehr Technical Support Illona Weber This information is available in alternate format upon request from the Office of Disability Services.

Recently Retired Faculty: Mrs. Ellen Lund Dr. Terrence McCabe Mr. Brian Nankervis Dr. Ernest Ratliff Recently Promoted Faculty: Dr. Jennifer Czocher Dr. Daniela Fererro Dr. Hiroko Warshauer Dr. Yong Yang 2

Table of Contents Greetings from the Chair 

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Department News 

4

Student Activities 

5

Seminars 6 Faculty Updates

8

Award Winners

10

Remote Learning

12

Give Back

13

Math in the Picture Winners

14

2019 PhD Graduates

Zhaochen Song

Texas State University

2020 PhD Graduates

Teresa Salazar East Texas Baptist University Xiaowen Cui Layla Guyot The University of Texas at Austin Christina Koehne State University of New York at New Paltz

Greetings from the Chair Hello to all you wonderful supporters of Bobcat mathematics. I hope you enjoy reading about, and even viewing, some of the exciting activities and opportunities that abound in the Department of Mathematics. I consider myself to be extremely lucky to be a member of such a fabulous department. Our department is great due to our wonderful students, super-talented staff, and amazing faculty, including twelve exciting new hires six Tenure/Tenure-track prof essors and six Lecturers (you can read about them on pages 8 and 9). Word is out that this is a great department. We all know that attending a university is more than just attending formal courses. In our department, faculty are not just dedicated educators but are also keeping up with the latest research in mathematics, statistics, and mathematics education practices. Consequently, Fridays are not a quiet time in Derrick Hall. We have multiple seminars (see pages 6 and 7) that meet regularly to explore contemporary research in topics such as mathematics education, topology, statistics, algebra, differential equations and discrete math. Presenters may be students, faculty, or renowned invited guests. In addition, we have regular colloquia, Women Doing Math, Talk Math 2 Me, and cocurricular activities for students such as Problem Solvers, Math Club, Pi Mu Epsilon, and a Putnam team.

as chair. This is a testament to the hard work and resilience of our Bobcat mathematical community.

Dr. Susan Morey DEPARTMENT CHAIR

Our reputation is growing wtih our doctoral graduates now employed in universities across the country. Our faculty and students both attend and host conferences. As Texas State progresses towards an R1 research classification, the Department of Mathematics will be an essential part of that research culture. While most of this newsletter highlights the year 2019, we extended coverage through spring 2020 due to the unprecedented events since March. I am so very proud of the way EVERYONE in our department reacted to the transition to remote learning and really put students first. Mathematicians are first and foremost problem solvers, Faculty, staff, and students all rose to the task of solving new problems with aplomb. While there were a few bumps along the way, I received more notes of thanks and appreciation from students this semester praising their instructors than in any other semester I’ve spent

Alpha Chi Favorite Professors

As if graduate school was not challenging enough, our graduate students found themselves in the unique situation of learning to be both online instructors and online students, all while continuing with their research. Some even defended their theses and dissertations online. Based upon how they faced these unprecedented challenge, I know our students will represent us well when they leave Texas State to continue their promising careers. Finally, I would like to thank our staff: Ms. Melinda Guerrero, Ms. Dee Ann Miller, Ms. Amanda Garza, Ms. Illona Weber, and Ms. Katie Alonzo. All were ready and willing to go the extra mile to help faculty, graduate students, and undergraduate students make the transition to online learning. From answering a multitude of questions to being on campus to make sure supplies were delivered as needed, our staff were amazing. While the many things they did cannot be detailed here, we would be remiss if we did not thank Ms. Illona Weber, our technology support person, who pulled together a Zoom orientation class in record time. She also set up Math CATS so that tutors could continue tutoring online using Zoom, and was instrumental in pulling together videos for our awardwinning students and retiring faculty.

Alpha Chi, a coeducational academic honor society, recognized nine professors from the Department of Mathematics as favorite professors: Dr. Elizabeth Balmer, Dr. Roberto Barrerra III, Dr. Sean Corrigan, Dr. Julio Dix, Dr. Anton Dochtermann, Dr. Jason Juett, Dr. Piyush Scroff, Mr. Shane Lowe, and Ms. Ellen Robinson. 3

Department News

Department Hosts Group Theory Summit Dr. Yong Yang and Dr. Thomas Keller were coinvestigators of the China-U.S. Group Theory Summit held at Texas State University, August 22 - 25, 2019. This event brought together Group Theorists from the United States and China in a first-ever conference focused on strengthening the ties between researchers in both countries. Fourteen Plenary speakers presented, seven from each country.

Math and Music Event Standing Room Only On May 3 the Department of Mathematics, presented Cellist Francesco Mastromatteo and Distinguished Professor Nico Schuler. The event was co-sponsored by Common Experience, Mathworks, and the Department of Music. As part of Math Awareness Month, the event showcased the relationship between music and mathematics to a standing-room only crowd.

“Flannel and Frost” Featured at Faculty Festivities The theme of the 2019 Annual Department of Mathematics holiday luncheon and awards ceremony was “Flannel and Frost,” although the day was far from frosty. The 294 pounds of food collected was donated to the Hays County Food Bank.

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Award Winners were: Service (Upper) - Maria Acosta, Eugene Curtin Service (Lower) - Anton Dochtermann, Glynda Betros Research (Upper) - Shuying Sun, Daniela Ferrero Research (Lower) - Wade Hindes, Kate Melhuish Research (Graduate Student) - Christina Koehne (Ph.D.), - Josephine Reynes (Masters) Teaching (Upper) - Jessica Bishop, Ray Treinen Teaching (Lower) - Hwa Young Lee, Terry McCabe Teaching (Lecturer) - Walter Dorman, Shane Lowe

Student Activities Putnam Competition The Eightieth Putnam Mathematical Competition was held in December, 2019. Texas State had its best showing yet, placing 107th across the United States and Canada. Congratulations to Keven Altenhoff, Ram Moore and Isaiah Silaski (who placed 276 and was mentioned in the announcement of winners document). Faculty members Dr. Tim Chase, Dr. Cameron Farnsworth, Dr. Cody Patterson, and Dr. David Snyder assisted with the event.

Movie Night Pi Mu Epsilon and Math Club hosted a movie night showing “Hidden Figures.” The event was open to everyone with the not-sohidden motive of showing the importance of Mathematics. Popcorn was sold to raise funds to support travel to MAA Mathfest as well as to fund social activites for PME and Math Club.

Grad Students Present at PME Texas State University had a large representation at the 41st annual meeting of the North American Chapter of the International Group for the Pyschology of Mathematics Education in St. Louis. Several graduate students, past and present, as well as faculty members presented.

Pi Day Celebration a Smashing Success To celebrate Pi Day, March 14, the Math Club held a pie sale on the quad where Dr. Rusnak (left) and Dr. Shroff (below) participated in the “pie your professor” fundraiser.

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Semin Extending learning beyond and beyond the campus

Algebra & Combinatorics

Sponsor: Dr. Anton Doch Meets every Thursday m

Differential Equations and Applied Math Seminar

Colloquium

Sponsor: Dr. Anton Doch Meets selected Friday a

Sponsor: Dr. Ray Trienen Meets every Friday morning

Discrete Math Seminar Sponsor: Dr. Jian Shen Meets every Friday afternoon

Math Education Seminar Sponsor: Dr. Kate Melhuish Meets every Friday afternoon

Women D

Sponsor: D External sp

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nars the classroom,

s Reading Seminar

htermann morning

m

htermann afternoons

Statistics Seminar

Sponsor: Dr. Vera Ioudina Meets every Friday afternoon

Talk Math to Me

Sponsor: Ms. Ellen Robinson Meets every Friday afternoon

Topology Seminar

Sponsor: Dr. David Snyder Meets every Friday morning

Doing Math

Dr. Daniela Fererro peakers as scheduled

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New Lecturers Connor Ahlbach Originally from Pacifica, CA, Dr. Ahlbach received his Ph.D. from the University of Washington in Seattle. His area of interest is researching algebraic combinatorics. He has taught in environments ranging from a prison to advanced high school students. In his spare time, he likes to do Aikido, Magic the Gathering and watch international soccer.

Megan Farrell A native Austinite, Ms. Farrell received both her B.S. and M.S. in Mathematics from Texas State University. Her areas of interest include knot theory and algebraic topology. She was the winner of the Math in the Picture contest at Texas State in both 2017 and 2018. She enjoys rock climbing, painting, hiking and swimming.

Chetak Hossain

From Wilmington, DE, Dr. Hossain received his Ph.D. in Mathematics from North Carolina State University. His research interests include enumerative, algebraic, and topological combinatorics. He enjoys playing digital card games, reading and watching television.

Jaraslow S. Jaracz Dr. Jaracz received his Ph.D. in 2019 from Stoney Brook University. Originally from New York, his research involves geometric inequalities in general relativity, such as the Penrose inequality. He is also interested in Riemannian and pseudo-Riemannian geometry, partical differential equations, and geometric analysis. He received the Perley Lenwood Thorne Medal in Mathematicx from NYU in 2013.

Westin King

From Keller, Texas, Dr. King received his Ph.D. in Mathematics from Texas A&M University. While a student there, he founded and named the Texas A&M SIAM Graduate Student Chapter. He is interested in enumerative combinatorics. His research to date has been on parking functions defined on directed graphs. In his spare time, He liked playing Dungeons and Dragons as well as trying to optimized his character to take advantage of the other party members’ strengths and weaknesses to make the game more enjoyable and rewarding for everyone.

Zhaochen Song Originally from Qingdao, China, Dr. Song received his Ph.D. in Mathematics Education from Texas State University. His research interests include teachers’ pedagogical content knowledge, cultural beliefs towards teaching, and comparative study of Mathematics Education across different cultures. In his spare time, he enjoys classical music and practicing traditional Chinese calligraphy.

Mathworks Receives Grants

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Starting with a one-time grant in 1990 to hold a 4-week residential math program for 12 students and four teachers, Mathworks has obtained an international reputation, now providing 60 high school students with a 6-week summer experience to not just strengthen their math skills but also engage in original research projects. Mathworks recently received a $49,000 grant from the Harman-Mayes-Sooch Family Fund, a $16,000 grant from H-E-B Tournament of Champions Charitable Trust, and a $2,000 grant from the Lions Club, to support scholarships for students attending the Mathworks summer camps so that students in need can attend camp regardless of their financial situation.

New Tenure/Tenure-Track Professors Will Boney - Assistant Professor

A native Austinite, Dr. Will Boney received his Ph.D. in Mathematical Sciences from Carnegie Mellon University in 2014. He works in nonelementary model theory (an area of mathematical logic) and its connection to set theory and category theory. Before coming to Texas State, he spent some time at University of Illinois at Chicago and at Harvard. In his spare time, he enjoys spending time with his baby daughter.

Paul Dawkins - Associate Professor

Originally from San Angelo, TX, Dr. Paul Dawkins received his Ph.D. in Mathematics from the University of Texas at Arlington. He received the Best Paper Award from the Research in Undergraduate Mathematics Education Conference in 2015. He also received an Excellence in Undergraduate Teaching Award from Northern Illionois University in 2017. Away from campus, he enjoys board games, runnning, and eating food from around the world.

Jake Fillman- Assistant Professor

From Houston, Texas, Dr. Jake Fillman received his Ph.D. from Rice University. His research interests are in mathematical physics and operator theory. He was awarded the Annales Henri Poincare prize for the best paper published in the journal Annales Henri Poincare in 2014. Away from campus, he enjoys spending time with his wife, daughter, and two cats, as well as hiking, reading science fiction and playing the piano.

Nestor Guillen - Assistant Professor

Originally from the city of Valera in the Venezuelan Andes, Dr. Guillen received his Ph.D. in Mathematics from The University of Texas at Austin. He works on partial differential equations, with a particular interest in free boundary problems and optimal transport. He enjoys playing video games and listening to audio books and spending time with his new baby girl, Eleanor.

Cody Patterson - Assistant Professor

Dr. Patterson received his Ph.D. in Mathematics from The University of Texas at Austin in 2010. His research investigates secondary students’ and teachers’ mathematical meanings for concepts and procedures in high school algebra.

Hiro Lee Tanaka - Assistant Professor

Dr. Tanaka received his Ph.D. in Mathematics from Northwestern University.

Faculty Trivia: Which two new professors introduced above were campers and later counselors at Mathworks? (Answer on page 11) 9

Math Department Award Winners -- Spring 2019 Undergraduate Recognition for Academic Achievement Presented to undergraduate mathematics majors who have completed at least 30 hours of college level course work at Texas State and have a Texas State grade point average of at least 3.00 but less than 3.25. Raymond Porter Justin Eccles Arsha Amit Brittany Rister Jordan Goble Psalm Baradi Noel Sandoval Jacob Grant Monique Bebley Carrie Schaible Shervin Hawley Lora Blanco Avery Sheldon Timothy Jackson Chaz Chism Rylee Taylor Dalton Kiefer Norman Contreras Jennifer Thompson Alexandra Lara Megan Cook Andrew Tkacs Yesenia Macias Stephanie Dille

for Academic Distinction

for Academic Excellence

Presented to undergraduate mathematics majors who have completed at least 30 hours of college level course work at Texas State and have a Texas State grade point average of at least 3.25 but less than 3.6.

Presented to undergraduate mathematics majors who have completed at least 30 hours of college level course work at Texas State and have a Texas State grade point average of at least 3.6.

Ngoc Aylesworth Sedric Bostic Amanda Cagle Alyssa Coleman Verginia Mae Dole Alexandra Farrar Jordan Fox Erika Franco Phillip Frasquieri Elena Garcia Tianna Glover Natalie Gomez Juliette Heyman Tai Hoang Irina Ionita Hayden Isler

Giovanna Chavez Jimenez Allison Johnson Eamonn Kent Casey Markham-William Patrick Massey Sam McClosky Rebekah Murrell Ashley Myer Ty O’Brien Cloe Rape Laura Rice Ethan Roberts Franklin Rojas Alexander Shaffer Santiago Torres Mallori White

Constance Angeley Andrew Baker Hannah Brown Blake Buell Mikaela Enters Garrett Faber Rienne Hammett Reginald Hebert Blake Hillier Ragan Holder Aaron Johnson

Graduate Recognition for Academic Excellence Presented to graduate mathematics majors at the Master’s level who have completed at least 15 hours of 5000+ level mathematics courses at Texas State and have a Texas State grade point average of at least 3.75. Ashraf Demian James Dylan Douthitt Leah Erenwert Megan Farrell Mario Yepes Lopez

James Mendoza Charles Reich Maria Tomasso Ryan Zamora

Presented to graduate mathematics majors at the Ph.D. level who have completed at least 36 hours of 7000 level mathematics courses at Texas State and have a Texas State grade point average of at least 3.75. Michael Abili Nichole Armand Joshua Fagan Layla Guyot Michael Hicks Sindura Subanemy Kandasamy

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Elizabeth Lambert Elaine Purvinis Teresa Salazar Zhaochen Song Monica Sustaita Brittany Webre

Rachel Kelmenson Kevin Leinneweber Molly McIndoe Christine Millard Ethan O’Dell Alexander Pegg April Polanco Abigail Polmanteer Jacob Ramseyer Calvin Ross Josephine Reynes

Don and Helen Cude Award Abigail Polmanteer Aaron Johnson Grant Smith Erica Stark Mia Hernandez Tianna Glover Robert and Brita Northcutt Scholarship Alina Rajbhanda Erica Stark Ram Moore R.H. Bing Award Casey Schlortt Ram Lal Seekri Endowed Scholarship Mark Renovato Lynn Tulloch Math Scholarship Benjamin Ruth

Rhys Roberts Kevin Rush Casey Schlortt Isaiah Silaski Kiley Smith Taylor Soliz Zachary Stence Anthony Tucci Diana Vu Shayla Williams Elizabeth Wrightsman

Ross and Sarah Wayment Endowed Scholarship Ryan Zamora Dylan Douhthitt Gabriele Lara Rebekah Mruell Layla Guyot Michael Hicks Isaiah G. Silaski Sindura Subanemy Kandasamy Graduate Student Award for Outstanding Achievement Ryan Zamora Michael Hicks CoSE Award for Outstanding Achievement Christina Koehne Dylan Douhthitt Rebekah Mruell Alina Rajbhanda

Math Department Award Winners -- Spring 2020 Undergraduate Recognition for Academic Distinction

for Academic Achievement

Presented to undergraduate mathematics majors who have completed at least 30 hours of college level course work at Texas State and have a Texas State grade point average of at least 3.25 but less than 3.6.

Presented to undergraduate mathematics majors who have completed at least 30 hours of college level course work at Texas State and have a Texas State grade point average of at least 3.00 but less than 3.25 Gisell Salinas Amir Jaimes-Reyes Randy Baker Noel Sandoval Macy Kidwell Psalm Baradi Nathan Sotelo Alexandra Lara Alyssa Coleman Megan Sullivan Jailong Li Samantha Danes Traveler Surley Raul Lopez Stephanie Dille Jennifer Thompson Yesenia Macias Robert Espinoza Preston Tiff Marlee Mazza Marcellus Garza Andrew Tkacs Joshua Owens Omar Gonzalez David Vartian Keondre Parker Mia Hernandez John Young Franklin Rojas Roman Iles

Joshua Avery Ngoc Aylesworth Monique Bebley Geoffrey Belden-Lipka Blake Buell Verginia Mae Dole Pamela Firsich Phillip Frasquieri Domingo Garcia Elena Garcia Allen Garza Tianna Glover Natalie Gomez Jacob Grant Justin Greilich Noah Hammerman Rienne Hammett Juliette Heyman Tai Hoang Ragan Holder Eamonn Kent Dalton Kiefer Robert Krohn

Casey Markham-Williams Ramon Marquez Sam McClosky Alejandra Munoz Di Nguyen Mariah Noggler Ty O’Brien Jacob Ramseyer Logan Reed Calvin Ross Victor Sanchez Alexander Shaffer Avery Sheldon Daniel Smith Seth Solis Madison Southerland Erica Stark George Strauch Mathieu Tahane Noe Tavira Harley Towne Pierce Van De Geijn Benjamin Whitsett

Don and Helen Cude Award Mohamed El Ansari Rowan Rollman

Lynn Tulloch Math Scholarship Leslie Alsobrook Brandon Price Butler

Robert and Brita Northcutt Scholarship Ram Moore Axel Sanchez Moreno

Graduate Student Award for Outstanding Achievement Masters: Zeliha Bicak Doctoral: Layla Guyot

Ross and Sarah Wayment Endowed Scholarship Josephine Reynes Morgan Byers Elizabeth Hewer Elizabeth Roan Dr. Young Kee Cho Christian Sayson

Ram Lal Seekri Endowed Scholarship Benjamin Heuss Axel Sanchez Moreno R.H. Bing Award Adrianna Pohlman

From page 9 : Dr. Boney and Dr. Patterson are former Mathworks campers.

for Academic Excellence Presented to undergraduate mathematics majors who have completed at least 30 hours of college level course work at Texas State and have a Texas State grade point average of at least 3.6. Keven Altenhoff Lucas Anesti Constance Angeley Jenna Ashby Andrew Baker Dolan Bates Kristofer Brandenberger Brandon Butler Morgan Byers Bailey Cheung Elizabeth Finch Erika Franco Andrea Garcia Jacob Gibson Ryan Jackson

Rachel Kelmenson Alexis Marquez Patrick Massey Tobias Mausner Ram Moore David Newland Ethan O’Dell Alexander Pegg Kathryn Perry Audriana Pohlman April Polanco Abigail Polmanteer Aline Rajbhandari Tristram Reed Mark Renovato

Neil Runcie Casey Schlortt Patricia Schutter Isaiah Silaski Grant Smith Kiley Smith Taylor Soliz Zachary Stence Caleb Sullivan Santiago Torres Bailey Trip Elena Velarde Huangyingrui Wang

Graduate Recognition for Academic Excellence Presented to graduate mathematics majors at the Master’s level who have completed at least 15 hours of 5000+ level mathematics courses at Texas State and have a Texas State grade point average of at least 3.75. Brooke Athey Deborah Beran Zeliha Bicak Jazmine Castanon Leah Erenwert

Lino Guajardo Noah Ledbetter Maria Tomasso Mario Yepes Lopez

Presented to graduate mathematics majors at the Master’s level who have completed at least 15 hours of 5000+ level mathematics courses at Texas State and have a Texas State grade point average of at least 3.75. Michael Abili Layla Guyot Elizabeth Hewer Michael Hicks Sindura Kandasamy Christina Koehne

Elizabeth Lambert Teresa Salazar Sunandini Sen Abdullah Suzek Brittany Webre

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Department Rapidly Transitions to Remote Learning At 10:58 AM on Thursday, March 12th, Dr. Trauth sent out an email announcing that spring break would be extended by one week and that classes would be held remotely for two weeks after that. Statewide stay-at-home orders soon extended the remote learning requirement through the remainder of the semester. Classes did not resume on campus. Fortunately, in response to careful and continued monitoring of the COVID-19 situation, the Department of Mathematics had already planned a just-in-case optional training opportunity for faculty and graduate students for March 13th, the Friday before Spring Break. The training was intended to ensure instructors had an awareness of online learning technology as well as to share creative solutions and strategies should remote learning become necessary. One of the few Fridays of the year when Derrick Hall might be a little quieter is the Friday before spring break. Not this year. All

hands were on deck. Faculty, staff, and graduate students filled multiple rooms in Derrick Hall to brainstorm and attend a crash course in Zoom conducted by Ms. Illona Weber. As part of the remote learning transition, all instructors were required to post a revised syllabus with plans for converting to an online platform by Wednesday, March 25th. These plans needed to recognize that some students might have little access to technology. This was a very challenging task for instructors with online teaching experience, yet most instructors had no experience with online learning. Personal plans for spring break were altered to allow for Zoom meetings of teaching forums to share and evaluate options. Meetings of these teaching forums continued throughout the semester. Instructors creatively made-do with what they had. Old Livescribe pens were dug out of drawers. White boards were set up in living rooms. Cell phones were innovatively mounted to enable video recordings. Power Point became an animation tool. As for much of the country, Zoom became an essential component of communication. It was used for holding interactive class, for recording lectures to be viewed online, for office hours and student appointments as well as for department meetings and teaching forums. People who had never heard of Zoom on March 11th quickly became confident users.

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Unlike students who chose to enroll in a class online, not all students had access to technology

including computers, printers, and internet. Fortunately, most students had cell phones and were able to download necessary apps such as Zoom or creating pdf’s on their phones. The department was also able to loan laptops to students. Students also struggled with balancing school and the rest of their lives. Many students worked in an essential worker capacity and were being assigned longer hours to work. Some had family members with health issues. Instructors encountered a new stress of providing emotional support to students during a pandemic. Some students just disappeared. Unfortunately, online assessment opened up new opportunities for honor code violations. But remote classes happened. Final exams were given using multiple creative strategies. The semester was completed. Grades were submitted. Instructors were exhausted. Then, after a brief respite, Summer I began, fully online. Learn more about how Texas State is responding to the Covid 19 pandemic.

Give back -- Support the Department of Mathematics Contributions to our scholarship funds are always welcome. As Texas State University and the Department of Mathematics grow, more and more students rely on your generous gifts to support their education. Please consider giving support to our majors in one of these scholarship funds.

______ Department of Mathematics Discretionary Fund ______ Mathworks Fund ______ Robert and Brita Northcutt Scholarship Fund – awarded to Texas State student majoring in mathematics with Texas State GPA of at least 3.0 on at least 30 hours of coursework at Texas State. ______ Lynn H. Tulloch Math Scholarship Fund – awarded to full time Texas State student majoring in mathematics and pursuing teacher certification. Preference should be given to athletes. The student should have a Texas State GPA of at least 3.0 on at least 30 hours of coursework at Texas State.

_____ Don and Helen Cude Scholarship Fund – awarded to undergraduate mathematics major pursuing teacher certification who has the highest GPA among senior level students who have completed at least seven upper level mathematics courses. ______ R. H. Bing Scholarship Fund– awarded to undergraduate mathematics major not pursuing teacher certification who have completed at least seven upper level mathematics courses. ______ Wayment Scholarship Fund ______ Seekri Scholarship Fund

To contribute, mark the scholarship fund you wish to donate to then complete the form below: (click here to access a pdf for a donation form) Name: ____________________________________________________________________________________________ Address: ___________________________________________________________________________________________ City: ________________________________________________ State: ________________ ZIP: ____________________ Country: _______________________________________ Phone: _____________________________________________ Email: ____________________________________________________________________________________________ Signature: _________________________________________________________________________________________ Check Number: _________________________________ Amount: ___________________________________________ Please return to Donor Services JCK 480 601 University Drive San Marcos, Texas 78666

Or give online by visiting donate.txstate.edu

Alumni Connections We’d like to hear from you -- our treasured alumni! We’ve made it easy for you to reconnect with Texas State University and the Department of Mathematics. Go to the website below and register your information so you’ll be able to stay connected with all the happenings here in San Marcos.

Connect on Twitter: @TxStateMath Connect on Facebook!

Search for Texas State University Department of Mathematics

www.math.txstate.edu/resources/alumni-connections.html 13

Math in the Picture Contest Winners 2019

People’s Choice Kassidy Kotulan Texas State University

Judge’s Choice

Lina Paola Espejo Ramirez Midland College The serve in a volleyball match is considered the first attack action in a game. The primary goal of an effective serve is to give the receivers the least amount of time possible to react. There are many types of serve but I will focus in the top-spin serve. The spin on the ball produces a force that acts perpendicular to the velocity of the ball. The top of the ball is spinning in the same direction as the ball’s motion. The ball is moving through individual air molecules as it spins.

 The math rippling on top of the San Marcos River is a brilliant method to learning where you live. The vibration frequency of the San Marcos Salamander coming to the surface of the water causes a wave to disperse in a trigonometric wave function. To understand the math of our ripple, we need to know the area inside of the ripple at time t, to then find the rate at which the area is increasing. We can find the solution to the area of our ripple by    (a) and the rate of change at which the area of our ripple increases at time t by (b)

On the top of the ball, the air molecules are being pulled forward by the spinning ball. However, the air is also being pushed backward as the ball moves. Thus, air molecules at the top of the ball and are moving faster than the ones in the bottom of the ball. The air molecules are accumulating on the top of the ball while in the bottom the spin of the ball compensates for the movement of the ball, pushing the air molecules backward off the ball so there is no accumulation. This difference in accumulation of air molecules creates a higher pressure on top of the ball. So, a ball moving through the air with top-spin, will experience a downward force due to the spin, which makes the ball drop to the ground faster than it would with no spin.

Using equation (b) you can find the rate of change of any ripple you create!

To find the size of the force due to spin use this equation: ||Fs|| = Ksω||v|| where ω is angular velocity and Ks is the proportionality constant for spin.

Texas State University Department of Mathematics 601 University Drive San Marcos, Texas 78666-4684

Picture from Midland College volleyball team (Lina Espejo) by Forest Allen