COLLOQUIUM
Department of Physics and Astronomy
California State University, Los Angeles
UNDERGRADUATE HONORS TALKS
Simulating Organic Molecules in the Protostellar Disk to Understand the Origins of Life
Jordan O’Kelley
B.S. in Physics Undergraduate, Cal State LA
Protostars possess remarkably complex chemistry throughout their various regions. The chemistry of the protostellar disk is of particular importance, as this is where planets are widely thought to form. The outer disk possesses low temperature and high density, making it uniquely well suited for the formation of simple organic molecules. Understanding the chemical abundances of organic molecules in the disk could provide important insights on the origins of life. RadChemT is a novel code which simulates astrochemistry for protostars in star forming regions. Its initial primary use was to simulate the relative densities of CO species throughout a protostellar region. The model proved to be accurate compared with observations of the protostar L1527. However, recent ALMA observations of L1527 indicate gas-phase presence of simple organic molecules, which were predicted to freeze out by RadChemT. Thus, new physical methods for desorption of these molecules from the dust grains are being explored, with the goal of accurately simulating these observations. Initial results indicate that the code can efficiently simulate abundances for all regions other than the outflow cavity, and that chemical desorption may account for the gas phase presence of simple organic molecules in the outer disk. We present results showing the effect of the new desorption mechanism on the chemistry model.
Thermal Decomposition of Nickel(II) Tetraphenylporphyrin: Core-Shell Nanoparticle Synthesis, Characterization, and Magnetic Properties
Cristian Reynaga Gonzalez
B.S. in Physics Undergraduate, Cal State LA
The exploration of Nickel(II) Tetraphenylporphyrin (NiTPP) under thermal decomposition provides crucial insights into the synthesis of novel magnetic materials with potential applications in nanotechnology and biomedical applications. Building upon our established research on the synthesis and characterization of iron porphyrin and iron phthalocyanine nanoparticles, this study investigates the structural evolution and magnetic behavior of NiTPP subjected to solid-phase pyrolysis at varying temperatures (300°C - 900°C) and times (10 - 240 minutes). Through a range of characterization techniques, including Powder X-ray Diffraction (PXRD), Physical Property Measurement System (PPMS) with Vibrating Sample Magnetometry (VSM), and Scanning Electron Microscopy (SEM) we attempt to interpret the interplay between pyrolysis conditions and the resultant nanoparticle properties. The emergence of magnetic core-shell structures and the impact of subsequent annealing in oxygen and nitrogen atmospheres on the nanoparticles’ morphology and magnetic properties are investigated. As we compare our initial NiTPP findings with previous work, our goal is to replicate and refine synthesis procedures for various metal centers including cobalt, copper, and zinc within the porphyrin matrix. In doing so, we attempt to identify pathways that allow the tailoring of morphology and magnetic characteristics in nanoparticles.
Thursday, April 18, 3:05 - 4:20 PM
In-person: BIOS 241
Spring 2024 Department of Physics and Astronomy Colloquium Schedule
(All talks presented via Zoom unless otherwise stated. This schedule will be updated throughout the semester.)
- January 25: no colloquium
- February 1: Dr. Charlotte Olsen, CUNY City Tech, "Exploring the role of environment on galaxy evolution through galaxy star formation histories"
- February 8: Dr. Al-Amin Dhirani, University of Toronto, "Quantum “nanoengineered” materials using a building-block approach"
- February 15: Dr. Amruta Jaodand, Harvard & Smithsonian, "The Enigmatic Transitional Millisecond Pulsars"
- February 22: Dr. Katy Rodriguez Wimberly, CSU San Bernardino, "Ultra–faint Dwarf Galaxies: Their Evolutionary Histories & Galactic Correlations," in-person
- February 29: Dr. Joanna Piotrowska, Caltech, "Putting Breaks on Star formation in Galaxies: The Cosmological Impact of Supermassive Black Holes," in-person
- March 7: Physics & Astronomy Career Panel featuring Dr. Margaret Lazzarini, Carl Heft, Carey Weisberg, C.J. Salgado, and Bing Jiang, in-person & Zoom
- March 14: Dr. Natalie Nicole Sanchez, Carnegie Observatories and Caltech, "Connecting Cosmic Gas Flows, Supermassive Black Hole Growth, and Galactic Evolution," in-person
- March 21: Dr. Francisco Mercado, Pomona College and Caltech, "Nature vs. Nurture: How internal and external processes shape galactic interiors," in-person
- March 28: Dr. Cliff Johnson, Northwestern University and Adler Planetarium, "The Universe and the Zooniverse: Exploring the Cosmos with Millions of Citizen Scientists"
- April 4: Spring Break, no colloquium
- April 11: Dr. Ashmeet Singh, Whitman College, "A Quantum Fueled Universe: Toolkit for Scalar Fields in Universes with Finite-Dimensional Hilbert Spaces"
- April 18: Undergraduate Honors Talks featuring Jordan O'Kelley, "Simulating Organic Molecules in the Protostellar Disk to Understand the Origins of Life," and Cristian Reynaga Gonzalez, "Thermal Decomposition of Nickel(II) Tetraphenylporphyrin: Core-Shell Nanoparticle Synthesis, Characterization, and Magnetic Properties," in-person