PALOOZA is a one day event wherein students are able to give 15 minute talks or poster presentations about their current research so we can learn what our colleagues are doing, learn something new while doing so and get to know each other a little better. Undergraduates are welcome too!
The event takes place this year on Saturday, April 13th, starting at 9 am. Food and drink will be offered both in the morning as a breakfast and afternoon as a lunch.
This event is supported by the University of Kansas Department of Physics & Astronomy.
:)
High Mountain Asia’s (HMA) water resources are subject to changes and imbalances as climate change progresses. Research studies focused on High Mountain Asia are often either coarse large-scale studies or small-scale case studies that do not allow regional officials to make informed, actionable decisions within their spheres of influence. Previous work by Immerzeel and others in 2020 characterized changes observed in major hydrologic basins in HMA and calculated their vulnerability and importance for environmental and anthropogenic water demands. Since 2016, NASA’s High Mountain Asia Team (HiMAT) has been tasked with furthering our understanding of the sensitive relationship between HMA’s cryosphere and hydrosphere. HiMAT’s recent advances in modeling glacier behavior provide the opportunity to update Immerzeel’s assessment of the relative importance of glacier water storage and supply in HMA. In this study, we use data developed by HiMAT to calculate a monthly glacio-hydrologic index composed of the glacier storage and the glacier water yield for all HydroSHEDS level 7 basins in High Mountain Asia. This index is taken one step further and projected to the end of the century. In doing so, we can analyze the long-term effects of climate change on the water yielded by glaciers on a higher temporal and spatial resolution than previously done. This glacio-hydrologic disturbance index lays the groundwork for future indices that include snow, hazards, extreme events, and other environmental disturbances.
The abundances of volatile elements like carbon, oxygen, and nitrogen (CNO) bridge the gap between protoplanetary disk chemistry, stellar composition, and planetary formation, accretion, and migration mechanisms. CNO abundances can trace a planet’s formation location relative to H$_2$O, CO$_2$, CO, and N$_2$ “snowlines”, or the distance from the star at which these volatile elements sublimate. By comparing elemental and isotopic CNO ratios measured in giant exoplanet atmospheres to complementary measurements in their host stars, we can determine whether the planet inherited stellar abundances consistent with in situ formation near the host star, or abundances consistent with formation in outer regions of the protoplanetary disk followed by an inward migration and accretion of materials from various portions of the disk. Here, I provide an overview of host star and companion planet CNO isotope ratios ($^{12}$C/$^{13}$C, $^{14}$N/$^{15}$N, and $^{16}$O/$^{18}$O) as they relate to the formation and evolution of planetary systems. To date, there are still only a handful of exoplanet systems where we can make a direct comparison of elemental and isotopic CNO abundances between an exoplanet and its host star. I will also discuss recent CNO isotope ratio detections in sub-stellar objects from both ground- and space-based observatories. Finally, I will share my near-infrared spectroscopic analysis to derive $^{12}$C/$^{13}$C, $^{14}$N/$^{15}$N, and $^{16}$O/$^{18}$O in planet-hosting cool dwarf stars using MARCS model atmospheres and the spectral synthesis code TurboSpectrum.
We present work towards new methods for precision $e^+$ & $e^-$ luminosity at future Higgs factories. The standard method of using Bhabha scattering ($ee\to ee$) is reviewed. An alternative channel of DiGammas ($ee\to\gamma\gamma$) is presented. A new method, dubbed ''3Beam'', is presented for the first time. 3Beam uses a third beam, comprised of photons, to precisely measure the $e$ & $\gamma$ luminosity. We explore how the $e$ & $\gamma$ luminosity could reduce the $e^+$ & $e^-$ luminosity uncertainty to levels that are acceptable for the goals of future Higgs factories.
Political polling has long been seen as the cornerstone of election prediction, gauging public interest or apathy towards a given candidate and inspiring fear or complacency in incumbents nationwide. But polling in US elections can be far from accurate, and indeed the efficacy of political polling has been under heavy scrutiny since the 2016 election that saw Donald Trump swept into the highest office. This paper seeks to tease out the spatial impacts on political polling that are common in US elections both at the national and state level, utilizing election result data to understand the spatial component of polling error. Using the analysis of these past data this paper then seeks to lay out some cautions for early polling for the 2024 election cycle.
Cosmic rays with energies above then the 1Eev is known as the UHECR(Ultra High Energy Cosmic Rays). When a primary UHECR undergoes through an inelastic collision with the a nucleus in the atmosphere, it transfers the energy to the secondary particle and form the air showers. These air showers can cause the radio emissions through geomagnetic emissions and Askaryan radio emission. The in-ice antennas are then used to detect these radio signals. We will discuss the possible detection of the UHECR in ARA(Askaryan Radio Array) detector.
Waste materials are ontologically inseparable from the context of their production. While much early food waste research has focused on quantification and consumer psychology, researchers in a range of disciplines would now benefit from alternate frameworks in which to spatialize the chimerical matter of food waste. To suggest generative paths for the future of food waste research, this study investigates spatial concepts already engaged in “emplaced” household food waste surveys published between 2012 and 2022. Surveys administered within defined geographic areas are considered emplaced. Sixty-eight relevant papers were identified in a systematic literature review. Resulting themes, including regional memberships, questions of scale and synecdoche, qualities of place, food cultures resulting from specific socio-spatial arrangements, and temporal consequences for organic matter, were structured according to Massey’s 2005 spatial provocations and propose fruitful directions for geographers to continue advancing the study of food waste.
chill
Submarine melting of icebergs are a large source of freshwater within Greenland fjord systems. This input of freshwater can alter the ocean heat flux near marine terminating glaciers, impacting ice-ocean exchanges at the glacier front. A sikkusak might promote heat transfer by enhancing fjord circulation, yet act as a heat sink from an increase in iceberg melt production. Traditional modeling methods often rely on approximate iceberg concentrations and distributions within fjords limiting the connection to individual glacier characteristics such as calving style and sikkusak configuration. With recent advances in iceberg detection from satellite-based synthetic aperture radar (SAR) imagery using machine learning algorithms, we are able to detect bi-weekly ice sheet wide iceberg distributions including icebergs within the sikkusak. Here we integrate an iceberg melt model with iceberg locations, distributions, and sikkusak extent derived from Sentinel-1. We aim to determine if sikkusak alters fjord waters enough to inhibit heat transfer to specific glaciers. This approach considers an alternative role of sikkusak around Greenland – not for mechanical buttressing, but its role in heat transfer near the terminus.
Vanadium oxides have gained popularity in recent years as grid-scale battery storage. Most notably they are viewed as potential cathode materials for beyond Li-ion batteries. The ionic motion in these cathodes can be increased with the inclusion of various dopants and co-intercalants, and thus the battery performance. In this talk we present some recent experimental results and our progress describing the ionic migration barriers in Na co-intercalated V2O5 and the methods used to acquire these results.
We present a millimeter spectral analysis of a star forming region in the center of the Milky Way galaxy, the Galactic center. Cloud C (G0.380+0.050), located in the dust ridge, is one of the only hot cores in the Galactic center other than Sgr B2, a cloud that is known to be one of the most chemically rich sites for massive star formation in the Galaxy. We observed the J=1-0 transitions of the CO isotopologues, $^{12}$C$^{16}$O, $^{12}$C$^{18}$O, $^{12}$C$^{17}$O, $^{13}$C$^{16}$O, as a part of a larger survey of 30 positions in the Galactic center, using Atacama Large Millimeter/submillimeter Array with an angular resolution of 2" (0.08 pc). Our goal is to characterize the chemical composition of the dense star forming regions within Cloud C. Through fitting models for emission and absorption to our data we have been able to identify the molecules present within the spectra of these star forming regions. The chemical composition of this cloud is valuable information that allows us to have a better grasp on the initial conditions of massive star formation.
Memristors – a novel addition to the classical circuit elements of resistors, capacitors, and inductors – exhibit the ability to switch between low and high resistance states. This transition is made possible by forming and rupturing conductive filaments made of oxygen vacancy defects (VO) within the memristor. Recent research has focused on scaling memristor dimensions down to the nanometer scale while retaining an acceptable switching speed, endurance, and on/off ratio. At these near-atomic scales, controlling the geometry of the CF has proven to be essential to optimizing these memristor properties. One key factor of CF geometry control is controlling the VO quantity and concentration within the memristor. This talk will discuss two methods for controlling VO quantity and concentration: atomic layer deposition (ALD) for atomically precise introduction of VO into the memristor, and electrical tuning which can be used to modify the concentration of VO within the memristor. The discussion will explain how ALD tuning of the device, by adjusting the concentration of VO as well as the thickness of the insulating oxide are the principal structural factors that influence the memristor’s endurance. We also discuss how electrical tuning, specifically an applied bias' amplitude and duration, is capable of increasing memristor endurance as well as reviving failed memristors. The findings in this talk suggest a general rule of thumb for optimizing memristor endurance and performance.
This study investigates how the urban Rarámuri community in Chihuahua, Mexico, leverages digital storytelling to recontextualize elder knowledge for the younger generation. Through workshops, it enables youth to express ancestral wisdom in contemporary urban settings, fostering a dynamic cultural identity. This approach highlights the adaptability of traditional narratives via digital media, underscoring the importance of intergenerational dialogue. The findings aim to contribute to the broader discourse on sustaining indigenous cultures in the present.
The Himalayan mountains of Nepal comprise the highest elevations, deepest river gorges, and greatest topographic relief on Earth. Contributing to this extraordinary landscape are some of the world’s highest rock uplift rates and largest river systems. This research focuses on investigating the vertical incision of the Kali Gandaki River in Central Nepal to elucidate the spatial and temporal relationship between rock uplift and river erosion of large mountain belts. Recent fieldwork and remote sensing observations have revealed abandoned, uplifted, and incised river gravels perched high above the modern river, which spatially coincides with high rates of vertical uplift and previously identified major tectonic structures. Samples collected from these stranded gravels for geochronology will provide age estimates of these perched river deposits and therefore rates of vertical incision by the Kali Gandaki over the geologic past, shedding light on interactions between tectonic growth of the Himalayas and surface processes such as river dynamics.
Furthermore, we address the challenges posed by climate change and monsoon shifts in Himalayan rain shadow zones that impact the livelihoods of mountain communities. On August 13, 2023, record-breaking rainfall triggered a catastrophic debris flow in the Jhong Khola basin, a tributary to the Kali Gandaki River. This extreme event destroyed 29 houses, displacing over 150 individuals, and resulted in an estimated property loss of $7 million. Such events, including those from tributaries like the Jhong Khola, have profound impacts on river dynamics and the morphological evolution of major river systems. In Fall 2023, we conducted fieldwork at the Jhong Khola-Kali Gandaki confluence involving drone-based structure-from-motion (SFM) surveys to generate high-resolution digital elevation models (DEMs) of the areas most impacted by the extreme August 2023 event. By leveraging drone-based SFM data, satellite imagery, and local insights, we aim to quantify the recent event and identify potential causes. Additionally, we aim to categorize the impacts rapid sediment flux events such as this have on river dynamics. This research contributes valuable insights into the intricate interplay between tectonic processes, surface dynamics, and extreme events of the Himalayas, providing critical knowledge for understanding and mitigating the impacts of natural hazards on mountain communities.
There are thousands of identified gamma-ray sources in our Milky Way. Many of these sources have been studied using the Fermi-LAT satellite, which is sensitive to photons in the energy range between 20 MeV and 300 GeV. Among the gamma-ray excesses detected with the Fermi-LAT, there are candidates that no one has observed before, which are designated unassociated. This study uses data from the High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory to identify some of these Unassociated Fermi Objects (UFOs). The HAWC Observatory is sensitive to gamma rays in the range between 500 GeV and 100 TeV, the highest energy gamma rays ever detected. By correlating these two unique datasets, we will be not only identifying previously unassociated objects but will also be uncovering the most powerful accelerators in our Galaxy. Our results found at least one significant association from the gamma-ray source 3HWC J1837-066 from ~15 keV up to ~100 TeV. To pursue this study even further, we will study the energy spectrum measured by the three experiments to pinpoint the actual astrophysical object behind the gamma-ray emission. We will use these studies to prepare a Target-Of-Opportunity proposal to request observation time with the Swift-XRT instrument, which operates at even lower energy (from 0.2 to 10 keV).
Magnetic tunnel junctions (MTJ) are the promising spintronics devices for data storage, which have potential applications in the development of novel magnetic random access memories(mRAM). Here we studied magnetic tunnel junctions with 2D magnets CrOCl and CrSBr as the tunneling material, which are well-known magnets at low temperature. Here, we discuss tunneling magnetoresistance (TMR) measurements for our devices which can explain the magnetic states of CrOCl and CrSBr magnets at various temperatures and fields. We further plan to study interlayer coupling and spin-orbit coupling in our devices at high pressure.
yum yum :)
By maintaining magnetic order down to the single atomic layer limit, two-dimensional magnets (2D magnets) significantly broadened modern understanding of magnetism and revived interest in 2D materials for industrial applications. In particular, 2D magnets can serve as building blocks for emerging spintronics devices. The main limitation in large-scale applications of 2D magnets is that typical lateral sample sizes that can be achieved in research laboratories with micromechanical exfoliation are between 10 and 100 $\mu$m. This project aims to develop reliable macroscopic metal-assisted exfoliation of atomically thin films of 2D magnetic semiconductors such as CrSBr and CrOCl. We modified several gold-assisted exfoliation methods traditionally used on transition metal dichalcogenides (TMDs) to create large-area homogeneous films of selected 2D magnets. To assess the quality of the resulting films we use a combination of electrical transport measurements and atomic force microscopy (AFM).
Ultrathin (1-4 nm) films of wide-bandgap semiconductors play a vital role in numerous microelectronics application. However, the properties of these films can be significantly influenced by defects, particularly those originating from the interface between the substrate and the film. Motivated by this, an in vacuo atomic layer deposition (ALD) was developed for synthesis of ultra-thin Ga$_2$O$_3$/Al$_2$O$_3$ atomic layer stacks (ALS) on Al electrode. It is found that the Ga$_2$O$_3$/Al$_2$O$_3$ ALS can form an interface with the Al electrode with negligible interfacial defects under the optimal ALD condition whether the starting atomic layer is Ga$_2$O$_3$ or Al$_2$O$_3$. This interface is crucial for attaining an optimal and adjustable electronic structure and dielectric characteristic in the ultrathin Ga$_2$O$_3$/Al$_2$O$_3$ ALS. In-situ scanning tunneling spectroscopy (STS) confirms that the electronic structure of Ga$_2$O$_3$/Al$_2$O$_3$ ALS can have tunable bandgaps ($E_g$) between $\sim 2.0$ eV for $100\%$ Ga$_2$O$_3$ to $\sim 3.4$ eV for $100\%$ Al$_2$O$_3$, which agrees with DFT calculations. These bandgaps exhibit significant non-linearity as a function of Al concentration. Furthermore, the dielectric constant $\varepsilon$ of ultrathin Ga$_2$O$_3$/Al$_2$O$_3$ ALS capacitors is tunable through variation of the constituent Ga$_2$O$_3$ and Al$_2$O$_3$ atomic layer numbers from 9.83 for 100% Ga$_2$O$_3$ to 8.28 for $100\%$ Al$_2$O$_3$.
We present an initial analysis of emission from vibrationally excited molecules of cyanoacetylene (HC3N) in the NGC 253 starburst nucleus. As one of the nearest examples of a nuclear starburst ($D=3.5$ Mpc), the NGC 253 nucleus is a prime candidate for a detailed study of the physical conditions of an extreme star formation environment. The majority of the star formation activity in the central 200 pc of NGC 253 is concentrated in compact and embedded super star clusters (SSCs) which typically have radii of < 5 pc and masses of $10^5$ solar masses. The SSCs are deeply embedded and thus the star formation activity is almost invisible when observed in the optical and near infrared wavelengths due to extinction. To combat this, we utilize the Atacama Large Millimeter/sub-millimeter Array (ALMA) which provides observations of NGC 253 at the sensitivity, resolution, and wavelengths needed to peer into the clusters and constrain the process of massive cluster formation. The formation of such massive and compact clusters in the present day universe is rare. This mode of star formation was much more common in the early Universe, so these clusters are being extensively studied as a prototype for the starburst phase in galactic evolution. In this work, we use high-resolution (< 5 pc) ALMA observations in Bands 3 (84 GHz) and 7 (350 GHz) to isolate the emission from individual clusters. The purpose of this work is to use HC3N to measure the physical properties of the gas inside these forming SSCs, where other wavelengths cannot penetrate, in order to understand the structure of these star formation powerhouses. The ultimate goal of this initial work is to better characterize the formation and evolution of SSCs, and how this may be different from typical star formation in the present-day universe.
FLDPLN (Floodplain) is a low-computational-cost flood inundation mapping (FIM) model for inland basins that considers both backfill and spillover flow mechanisms. FLDPLN has been implemented for operational flood inundation mapping in the state of Kansas. Height Above Nearest Drainage (HAND) FIM is incorporated in the current version of the National Water Model (NWM), and its implementation was designed to permit mapping at scale across the continental United States (CONUS), while maintaining a modest computational cost. Our experiment documents the skill and efficiency of the FLDPLN model relative to the HAND model with respect to reference data sourced from satellite and aerial imagery, hydrodynamic models, and ground-observed watermarks. Results show that including FLDPLN in the suite of tools used with the NWM process has the potential to improve FIM accuracy beyond Kansas and to benefit communities across the country. The study dataset and instructions for processing and modeling simulations in this study will be publicly available via web repository.
Most massive galaxies host a supermassive black hole (SMBH) in their center. However, it remains a subject of debate how these SMBHs reached their current sizes. The standard model of growth for the most massive SMBHs is that they reached their current sizes through mergers of massive, gas-rich galaxies. However, studies which seek to test this theory have yielded mixed results. Examining the question of merger-driven black hole growth has historically been limited by extreme sampling biases. Studies with reasonable sample sizes are limited to the nearby universe, and studies in the distant universe are limited to a small number of large, bright galaxies. With the release of the first data from the James Webb Space Telescope (JWST), we can now resolve a population of dimmer galaxies at much greater distances, allowing this theory to be tested with a more complete population. We use citizen science volunteers to visually describe galaxy morphology and interactions, and SED fitting to measure galaxy properties, including black hole growth, in order to characterize the relationship between merging galaxies and black hole growth.