2022 Earth/Environmental Sciences, Technology and Engineering
The pre-recorded talks and posters on this page showcase the work of students who received NC Space Grant research funding during 2021-2022. The menu at right provides links to pre-recorded talks and posters by other funded students on additional topics.
2021-22 NC Space Grant Graduate Research Fellow
University of North Carolina at Charlotte
Graduate Student (Masters), Chemistry
Early Detection of Coral Bleaching using Surface Enhanced Raman Spectroscopy
As the global temperature rises, the Earth has been hit with a slew of environmental issues – including the coral bleaching epidemic. With current EPA projections, this forecasts coral to become extinct in the next 200 years. Coral organisms live symbiotically with zooxanthellae algae that live in and on its tissues. When the temperature rises and ocean acidification occurs, the zooxanthellae’s chloroplast will malfunction and begin to produce reactive oxygen species (ROS). ROS, which, will react to the surrounding water to produce hydrogen peroxide (H2O2) which will harm the coral and begin the bleaching process. Herein, we propose to develop a field-deployable optical biosensor using noble metal nanoparticles (NPs) and Raman spectroscopy to quantitatively detect the H2O2 content in the water surrounding coral. We will use a Raman tag attached to an NP surface as the nanoprobe, where the Raman tag is known to react with H2O2 resulting in a structural modification that can be detected using its unique SERS signal. We will use the anticipated data to determine the lowest concentration of H2O2 in water that is indicative of the early stages of the coral bleaching process; this correlating intensity will be labeled the “thresholding intensity”. Based on this, a software program can be used to produce a response when H2O2 is detected above the thresholding intensity. From this result, marine scientists can move forward with preservation and protection methods for that area of coral. This assay will offer a high sensitivity with a limit of detection (LOD) of H2O2 in the nanomolar concentration range. This will be comparable to other optical techniques and will be far more sensitive than current visual detection methods. This will yield early detection of the coral bleaching event.
Faculty Advisor: Jerry Troutman, University of North Carolina at Charlotte
2021-2022 NC Sea/Space Grant Graduate Research Fellow
University of North Carolina at Chapel Hill
Graduate Student (Masters), Environmental Sciences and Engineering
Mapping Heavy Metals as Drivers of Antibiotic Resistance in the Neuse River Watershed
Antimicrobial resistance (AMR) — the ability of infection-causing microorganisms to resist medicine normally used to treat the infections —is emerging as an urgent and high-impact issue with wide-reaching impacts on aquaculture, public health, and other disciplines reliant upon antimicrobials. This study investigates the influence of heavy metals (copper and zinc) as potential drivers of AMR in Enterobacteriaceae, a family of Gram-negative bacteria, collected from the Neuse River in North Carolina from the northern river basin in Raleigh down to the Neuse River Estuary. A total of 89 Enterobacteriaceae isolates were characterized with respect to antimicrobial resistance using the Kirby-Bauer disk diffusion method; an agar well-diffusion method was used to characterize metal resistance of isolates. To evaluate antibiotic resistance associations with heavy metal resistance, logistic regression analyses were calculated to examine the effects of zinc and copper on antibiotic resistance. This study finds that zinc resistance is significantly associated with copper resistance and both metals had significant associations with several of the 8 tested antibiotics. Using CHIRPS Daily — a USGS and UCSB daily precipitation dataset using satellite-retrieved and in-situ measurements — and Google Earth Engine, rainfall data was retrieved for a set amount of days prior to the day samples were taken from field sites. This rainfall data was then used in logistic regressions to which we found statistically significant associations among antibiotic and metal resistances to rainfall occurrence. To our knowledge, this is the first study to evaluate heavy metal influences on AMR in the Neuse River Basin, and therefore, the results may inform future monitoring and management efforts with respect to water pollution and microbial hazards and indicators in such settings.
Faculty Advisor: Michael B. Fisher, University of North Carolina at Chapel Hill
NASA Internship Award at Goddard Space Flight Center (GISS) – Summer 2021
Undergraduate Student (Junior), Civil Engineering
The Role of Acetone on Global Atmospheric Composition
Acetone is an abundant volatile organic compound with important influence on ozone and atmospheric self-cleaning processes. The budget of acetone is influenced by various sources and sinks. Direct sources include anthropogenic, natural vegetation, oceanic, and biomass burning emissions, while chemistry forms acetone from other compounds. Sinks include deposition onto the land and ocean surfaces, as well as chemical loss. The GISS Earth System Model, ModelE, is capable of simulating a variety of Earth system interactions. Previously, acetone had a very simplistic representation in the ModelE chemical scheme. This study assesses a greatly improved acetone tracer scheme, in which acetone’s sources, sinks, and atmospheric transport are now tracked in 3 dimensions.
Extensive research was conducted to assess how well past literature supported the new global acetone budget. Anthropogenic, vegetation, biomass burning, and deposition schemes fit well with previous studies. While their net fluxes were well-supported, source and sink terms for chemistry and the ocean were overestimated and underestimated, respectively. In iterations of the chemistry scheme, it was found that the production of acetone from hydrocarbon oxidation is a strong leverage to the overall chemical source. Spatial distributions reveal that ocean uptake of acetone dominates northern latitudes, while production is mainly in mid-southern latitudes. Ocean surface conditions influence ocean-acetone interactions and will be considered when modifying the ocean scheme in future work.
The seasonality of acetone-related processes was also studied in conjunction with field measurements around the world. These comparisons show promising results but have shortcomings at urban locations since the model’s resolution is too coarse to capture high-emission areas. Overall, an analysis of the acetone budget aids the development of the tracer in the GISS ModelE, a crucial step to understanding the role of acetone in the atmosphere.
Mentor: Kostas Tsigaridis, NASA Goddard Space Flight Center (GISS)
2021-22 Community College Undergraduate Research Program
Wake Technical Community College
Associate Student, Science
In this project, our team will help to track pollinator diversity in the Pollinator Meadow and around campus on Wake Tech’s North Campus. We will collect insect samples from the meadow (both the regular and native plant side) and from the flowerbeds. Then we will identify the insects to order and determine if the pollinator diversity is changing over time. Our goal is to compare our data with previous data collected from the same areas in 2018-2019 to analyze if the pollinator population is still declining. We aim to investigate what is causing the decline by focusing on habitat destruction alongside chemical factors and human interaction. This will lead to researching possible mitigating measures. The possible mitigating measures we will be focusing on are implementing more native plants, advocating environmentally friendly methods of maintaining the school environment, and possibly promoting bee-hive placement.
Faculty Advisor: Mary Christie, Wake Technical Community College