Physics and Astronomy Colloquium Schedule

(If you want on the Colloquium announcements email list, please send Joe Carson a note)

FALL 2020 Colloquium Schedule

(Usually Thursdays at 1:45 in RITA 387)

September 3rd, 2020   
Logan Oxener 
Title: A Study on the Longterm Effects of Stellar Activity on the Evolution of Planets

September 10th, 2020   
Ashley Dowd
Title: A Compilation of Systems That Are Both Novae and Dwarf Novae

September 17th, 2020
Chris Blouin
Title: TBA

September 24th, 2020
Pierce Hamilton
Title: TBA

Tri Nguyen
Title: Simultating Tilted Accretion Disks and Their Effects on Astrophysical Jets

October 8th, 2020

Peter Jang
Title: Energy Trading and Energy Finance

Abstract: Energy products have various forms and usages, but all energy products fall into two major categories: transportation energy and electricity. Crude oil is mainly refined and used for transportation, while renewable energy, coal, nuclear, and natural gas are mainly converted to electricity. This talk will discuss how an energy product is different from a stock (which is the most popular product in financial markets) in terms of a risk measure of price volatility and describe energy market participants and market infrastructure. This talk will conclude with a practical valuation of physical energy assets, natural gas storage and power plant, leveraging the concepts of optionality inherent in volatile energy market.

About the Author: Peter Y. Jang has research interests in interdisciplinary fields of finance, energy, and engineering. The areas include energy economics, renewable energy, financial derivatives, systems dynamics modeling, engineering management, operations research, and behavior economics. In August 2020 he earned a Ph.D. degree in Systems and Engineering Management at Texas Tech University. He joined the Ph.D. program after post-MBA sixteen years of experience in energy investment and trading in natural gas, electricity, and environmental products. His professional career roles include Director Deal Structuring and Senior Term Power Trader at Shell Energy, and Director Power Trading & Analytics at Repsol Energy. He holds an MBA degree in finance from The Wharton School, University of Pennsylvania, and a bachelor’s degree in business administration from Sungkyunkwan University, Korea.

October 15th, 2020
Chris White (Princeton/Flatiron)
Title: Observable Consequences of Tilted Disks around Black Holes

Abstract: As of only a couple years ago, astronomical observations can directly observe the gas falling into black holes on the size scales of event horizons themselves. In particular, the data coming from the supermassive black holes in the centers of our galaxy and M87 is in broad agreement with our theoretical models, consisting of thick disks of hot, diffuse plasma. Most modeling, however, assumes these disks are aligned with the spin of the black holes, while theoretically it would be surprising if nature were always so simple. Disks that are instead tilted showcase more interesting dynamics. I will discuss what sorts of signs of this we might look for in upcoming observations, and how neglecting the possibility of tilt could bias our inferences.

October 22nd, 2020
Caprice Phillips
Title: Detecting Potential Biosignatures in Super-earth Atmospheres with JWST

Abstract: No Solar System analog planet to super-Earths exists, a class of exoplanets with masses 2-10x Earth's mass which can retain more of their atmospheres. Super-Earth atmospheres can have different compositions from Nitrogen and Oxygen dominated atmosphere of Earth. The James Webb Space Telescope (JWST) will offer unprecedented insight into the atmospheric composition of potentially habitable super-Earths through transmission and emission spectroscopy. I will present work on the investigation of NH3 (ammonia, a potential biosignature) detectability on super-Earths with a H2 dominated atmosphere using the Mid-Infrared Instrument (MIRI) and the Near InfraRed Spectrograph (NIRSpec) on the upcoming JWST mission. We use a radiative transfer code, petitRADTRANS, to generate synthetic spectra of optimal targets for observations given their proximity to Earth (less than 50 pc), radii (1.7-3.36 Earth radii), and equilibrium temperature (less than 450 K). I will review the constraints of the MIRI LRS Instrument (flux ratio contrast of host star and planet of approximately 10^-4), and discuss optimal targets for this instrument. For NIRSpec, I will present how varying mean molecular weight of the atmosphere affects spectral features. Finally, I will discuss the use of PandExo to simulate mock observations with JWST and the detection significance findings for Ammonia features with transmission spectroscopy.

November 5th, 2020
Alex Pagnotta (Structural Engineer with Burns & McDonnell)
Title: Structural Engineering of the Power Grid during COVID-19

Abstract: The system for generating and delivering electricity to our homes and businesses is a complex assembly that requires an array of contributions from science and engineering disciplines. Substations are the critical nodes in this system. Dr. Pagnotta will provide an overview of the physical system, with an emphasis on substation operations and design. The engineering of critical infrastructure cannot stop during a pandemic, especially in the midst of threats to the grid (e.g. wildfires, hurricanes, heatwaves, etc.). Dr. Pagnotta will also cover how Burns & McDonnell and the industry have adapted to the work-from-home environment while maintaining a presence on our construction sites, and the importance of your education experience in a remote environment.

November 12th, 2020
Katharina Renken (Hapag Lloyd)
Title: What You Always (or Never) Wanted to Know About a Career in the Logistics Sector

Abstract and Bio: Katharina Renken received a Bachelor of Engineering degree in Engineering and Management from Jade Hochschule Wilhelmshaven in Germany (today: Jade University of Applied Sciences). Thereafter she participated in a double degree program between Jade Hochschule and Texas Tech University in Texas to receive a Master of Engineering in Engineering and Management in Germany and additionally a Master of Engineering in General Engineering in Texas. Katharina then worked at the JadeWeserPort, a green-field deep-sea container terminal, as a project engineer, before and after starting the operation. She returned to Texas Tech University in 2013 to aim for a PhD in Industrial Engineering and finished the PhD program with “excellent” in 2016. Since her homecoming to Germany in late 2016, Katharina first worked in the maritime research field, having addressed different topics among which are Terminal Operation Systems, innovative port technologies, sustainable (green) port projects and the digitalization of the port environment (“Port 4.0”) at Fraunhofer CML and for the Kühne Logistics University.

Her current work engagement brought her to one of the largest container carriers and ship operator Hapag-Lloyd and its terminal partnering program. She would like to show you how a baby seal, a ship horn and safety helmets play a significant role in her career and how great the possibilities for engineers are in the field of logistics. Be ready for some funny stories and personal insights about a truly global operation!

November 19th, 2020
Kate Owens (College of Charleston)
Title: Rethinking Traditional Grading

Abstract: For the last several years, I have implemented standards-based grading schemes in a variety of mathematics courses. The goal of standards-based grading (SBG) is to shift the focus of grades from a weighted average of scores earned on various assignments to a measure of mastery of individual learning targets related to the content of the course. In this talk, I will highlight some of the issues with traditional grading schemes, provide guidance about how to implement standards-based practices in courses, and share some things not to do when making the jump to SBG. I will also talk about the recent Mastery Grading Conference (June 2020), and how a small conference in Michigan morphed into a large multi-day webinar. I'll also share some practical tips for anyone considering organizing such an event.

December 3rd, 2020
Peter Kosec (Athena X-ray Observatory)
Title: Powerful Outflows in Accreting Systems of All Masses

Abstract: Accretion onto compact objects such as neutron stars and black holes is one of the most energetic processes in our Universe. While most of the material is infalling onto the accretor, several mechanisms can actually give rise to a powerful outflow of matter away from the accretion disc in the form of a wind. The velocity of the wind can reach tens of percent of the speed of light and therefore its kinetic energy can be very significant, and thus the outflow can strongly influence the surroundings of the accreting system. It is thought that disc winds from supermassive black holes contribute to or even drive active galactic nucleus feedback, an effect thought to shape a large fraction of galaxies in our Universe.

Accretion disc winds have been detected in many classes of accretors, however their physics, energetics, occurrence and therefore their impact is still poorly understood. In this talk I will present the recent observational results on disc winds in a range of accreting systems. I will particularly focus on Ultraluminous X-ray sources, a class of objects accreting at an extreme (super-Eddington) rate, a regime where powerful outflows of ionised material are naturally expected. I will also describe the new methods we developed for automated detection of wind signatures in high-resolution X-ray spectra. Finally, I will present the fascinating object Hercules X-1, a neutron star accretor which can provide a unique insight on the structure and physics of disc winds.