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Integrating Sustainability and Food Safety through Quantitative Microbial Risk Assessment and Life Cycle Assessment of Low-Moisture Foods
No full textFood safety and sustainability are critical concerns in the food industry. However, these areas are often evaluated separately, leading to an incomplete understanding of the overall impact of food production on human health. This dissertation aims to integrate food safety with sustainability to provide a comprehensive assessment of the impact of low-moisture foods on human health, using the almond processing supply chain as a case study.
In addition to conducting life cycle assessments (LCA) of almond processing, wheat flour production, and dried apple processing, this dissertation aims to create a framework to bridge the gap between sustainability and food safety. The objectives of this study are to develop an integrated approach incorporating disability-adjusted life years (DALYs) from endpoint LCA results and quantitative microbial risk assessment (QMRA), conduct a QMRA of almond processing to track the movement of Salmonella from the orchard to the consumer, investigate the parameters within the developed framework that most impact the estimated number of Salmonella cases.
This study uses a Monte Carlo simulation based on an established dose-response relationship. The model incorporates data on Salmonella prevalence, concentration on almonds, storage time, rate constants, and transfer coefficients derived from previously published literature and extrapolation for this model. It estimates the annual number of Salmonella cases under a 4-log pasteurization scenario and assesses the model\u27s sensitivity to various parameters, including prevalence and transfer rates.
The baseline risk model estimated approximately six cases of salmonellosis per year with a 1% prevalence rate. The probability of illness per serving was calculated to be 0.11 per one million servings. Sensitivity analysis revealed that increasing the prevalence from 1% to 10% resulted in 64 cases yearly. The model was also highly sensitive to transfer coefficients, with increased values significantly raising the estimated cases. The environmental impact assessments of almond, wheat flour, and dried apple production highlighted critical areas such as emissions, resource use, and transportation impacts.
This dissertation demonstrates the importance of integrating food safety with sustainability to assess the impact on human health. The developed framework captures the movement of Salmonella throughout the almond supply chain and provides insights into critical control points and intervention strategies. Integrating DALYs from LCA and QMRA offers a holistic measure of the health burden, bridging the gap between food safety and environmental sustainability
Germanium Based Superconductor Semiconductor Quantum Devices (2024)
Get PDFGermanium Based Superconductor Semiconductor Quantum Devices
The 3MT (Three Minute Thesis) is a research communication competition that challenges students to communicate the significance of their projects without the use of props or industry jargon in just three minutes. The winner of the 3MT competition moves on to the Council of Southern Graduate School’s Regional Conference in March 2025.https://scholarworks.uark.edu/mtsturpc/1078/thumbnail.jp
Separating Biomolecules to Save Lives (2024)
Get PDFSeparating Biomolecules to Save Lives
The 3MT (Three Minute Thesis) is a research communication competition that challenges students to communicate the significance of their projects without the use of props or industry jargon in just three minutes. The winner of the 3MT competition moves on to the Council of Southern Graduate School’s Regional Conference in March 2025.https://scholarworks.uark.edu/mtsturpc/1091/thumbnail.jp
How the Russia & Ukraine War is Contributing to Raw Materials Shortages in the Aerospace Industry
Get PDFThe aerospace industry, a key driver of the global economy, generates annual revenues exceeding 1.38 trillion by 2030. A substantial portion of this revenue—approximately $300 billion—stems from raw materials, which are integral to the manufacturing of aerospace components. These materials, including titanium, aluminum alloys, palladium, and neon, are essential due to their unique properties, such as lightweight strength, heat resistance, and suitability for extreme conditions.
However, the industry\u27s dependence on limited geopolitical suppliers has exposed vulnerabilities in global supply chains. The Russo-Ukrainian War has significantly disrupted the availability of critical materials like titanium, neon, and palladium, as both countries are major global suppliers. This disruption has led to severe shortages, inflated costs, and operational challenges for aerospace manufacturers. For instance, titanium sponge production in Russia and Ukraine, crucial for aerospace-grade alloys, has been severely impacted, while neon and palladium shortages have hindered semiconductor and thermal regulation technologies essential for modern aircraft.
In response, the aerospace industry faces urgent calls to diversify supply chains, explore alternative materials, and invest in sustainable practices such as recycling and advanced manufacturing techniques. These strategies aim to mitigate risks, reduce costs, and enhance resilience amidst geopolitical tensions. By addressing these challenges, the aerospace industry can sustain its pivotal role in advancing aviation, space exploration, and global technological innovation
Paste Properties, Hardened Concrete Properties, and Mix Design Process for Magnesium Phosphate Cement
Get PDFMagnesium phosphate cement (MPC) is a rapid-setting alternative cement typically used as a quick repair material. MPC has gained popularity in recent years due to its ability to reduce CO2 emissions, its strong chemical resistance, and potential use in large scale applications. There is currently limited research on the properties of MPC when varying the proportions of its ingredients. Several hardened concrete properties were analyzed on concrete mixtures made with MPC. A mix design process for MPC concrete is proposed based on testing of 300 MPC paste mixtures and 115 MPC concrete mixtures. A standardized mix design process is imperative for MPC to gain broader application in practice. The first chapter examines only paste mixture properties. Setting times, compressive strengths, and flow values are strongly affected by mixture characteristics such as the magnesia to phosphate molar ratio (M/P), water to binder ratio (w/b), chosen phosphate component and replacement rates, set retarder type, set retarder dosage, fly ash type (class C or class F) and replacement rate. This study found that lower M/P, higher w/b, higher set retarder dosages, and inclusion of class C fly ash provided longer setting times and higher flow values. Higher M/P, lower w/b, lower set retarder dosages, and no addition of fly ash provided higher compressive strengths. This work should aid in future studies seeking to develop non-proprietary MPC formulations. The second chapter investigates hardened properties of MPC. Compressive strength testing was conducted on 109 MPC mixtures and flexural strength, modulus of elasticity, and ultrasonic pulse velocity testing on 73 MPC mixtures. Eight different mixture design parameters were examined in this study to understand their effects on hardened properties. These included M/P (4, 6, 8), w/b (0.18, 0.2, 0.22), aggregate type (limestone, dolomite, trap rock, sandstone), aggregate size (#57, #7), aggregate percentages (50%, 60%, 70%), paste to aggregate ratio (0.5, 0.7, 1), replacement rates of class F fly ash (20%, 40%, 60%), and set retarder dosages (4%, 6%). Existing relationships between compressive strength and other engineering properties were found to be generally applicable to MPC concrete despite the major differences in chemistry. Demonstrating how to achieve specified hardened properties of MPC could encourage the use with this material in practice. The third chapter proposes a mix design process based on the already familiar American Concrete Institute (ACI) 211 document for portland cement concrete mix design. The effects of mixture parameters such as M/P (4, 6, 8), w/b (0.18, 0.2, 0.22), aggregate type (limestone, dolomite, trap rock, sandstone), aggregate size (#57, #7), aggregate percentages (50%, 60%, 70%), binder to aggregate ratio (0.5, 0.7, 1), replacement rates of class F fly ash (20%, 40%, 60%), and set retarder dosages (4%, 6%) on setting time, slump, slump flow, and compressive strength values detailed in the other chapters were used to recommend optimal starting values for trial mixture designs. The result is a mixture design process able to produce an initial mixture design with adequate workability and strength properties for MPC concrete
Utilizing Spatial Transcriptomics to Compare Gene Expression in Volumetric Muscle Loss Injury Recovery
No full textVolumetric Muscle Loss (VML) injuries are known to disrupt the normal regenerative process via fibrosis leading to an extensive permanent loss of muscle function. The specific causation of this disruption remains to be defined; however, with new developments in transcriptomics, genetic trends can be identified across regions of tissue over time. This study follows VML injuries within the tibialis anterior of a mouse model for fifteen days after initial injury to attempt to identify expected transitions in healing. Genetic presence began to become more diversified as recovery progressed from four to fifteen days post injury with spatial clusters becoming globalized based on inflammatory or regenerative effects. The evolution of these clusters was based upon the elimination of inflammatory related genes and appearance of muscle diversification related genes as fifteen days post injury was approached. Limitations did exist regarding the heterogeneity of spatial counts and distribution; however, improvements in procedure and study design would likely mitigate this in future studies. Extensive percentages of mitochondrial gene counts were established at regions of low spatial counts and needs to be investigated further to ensure that future studies involving possible cellular death will not affect spatial counts. Low resolution and specificity of spatial clusters also limited the ability to draw extensive conclusions regarding transitions in healing, but integrating this technology with single-cell transcriptomics, immunofluorescence, and other quantitative assays will greatly improve these issues. Overall, spatial transcriptomics offers researchers an innovative approach to quantify and visualize stages of healing in VML recovery studies that could be leveraged in conjunction with existing methods to better understand the complex cytokine pathways behind these injuries
Queer Latinx Bodies and AIDS: Joey Terrill’s “Still Here” and “Once Upon A Time”
Get PDFThrough two interviews conducted two years apart, the author and artist Joey Terrill offer an intimate historical trajectory rooted in the singular voice of the artist through the discussion of artworks in the exhibitions “Joey Terrill: Still Here” and “Joey Terrill: Once Upon A Time: Paintings, 1981–2015”. The method of storytelling, interview, and art representation chronicles the artist’s emotional, intellectual, and embodied experience of illness, queerness, and resistance as an HIV-positive queer Chicano
Blackberry Growth Monitoring and Feature Quantification with Unmanned Aerial Vehicle (UAV) Remote Sensing
Get PDFEfficiently managing agricultural systems necessitates accurate data collection from crops to examine phenotypic characteristics and improve productivity. Traditional data collection processes for specialty horticultural crops are often subjective, labor-intensive, and may not provide accurate information for precise management decisions in phenotypic studies and crop production. Reliable and standardized techniques to record and evaluate crop features using agricultural technology are essential for improving agricultural systems. The objective of the research was to develop a methodology for accurate measurement of blackberry flowers and vegetation coverage using UAV remote sensing and image analysis. The UAV captured 20,812 images in the visible spectrum, and ImageJ software (version 1.54k) was used for segmenting floral and vegetative coverage to calculate variety-specific flower coverage. A moderately strong positive correlation (r = 0.71) was found between flower-to-vegetation ratio (FVR) and visually estimated flower area, validating UAV-derived flower coverage as a reliable method for estimating flower density in blackberries. The regression model explained 51% of the variance in flower estimates (R2 = 0.51), with a root mean square error (RMSE) of 2.79 flower/cm2. Additionally, distinct temporal flowering patterns were observed between primocane- and floricane fruiting blackberries. Vegetative growth also exhibited stability, with strong correlations between consecutive weeks. The temporal analysis provided insight into growth phases and flowering peaks critical for time-sensitive management practices. UAV computer vision for quantifying blackberry phenotypic features is an effective tool and a unique methodology that speeds up the data collection process at high accuracy for breeding research and farm data management
Two-dimensional Quantum Material Identification Via Self-attention and Soft-labeling in Deep Learning
Get PDFDetecting two-dimensional (2D) materials in silicon chips presents a significant challenge in the field of quantum machines due to the difficulty of data collection. Specifically, among thousands of flakes, not all flakes are useful or well-annotated, resulting in noisy and hard samples within the dataset, which challenges the deep neural network (DNN) to learn. To address this problem, we propose a novel method for identifying quantum 2D flakes even when there is a high rate of missing annotations in the input images. In particular, we first propose a new mechanism for automatically detecting false negative flakes that are missing annotations. Second, we introduce an attention-based loss function to mitigate the negative impact of these unannotated flakes on the DNNs. The experimental results demonstrate that our method outperforms previous approaches