Biomedical Engineering and Bioengineering Commons^™

Representativeness Evaluation Of Delta-Flux Eddy Covariance Towers For Assessing Greenhouse Gas Emissions From Rice Fields In The Mid-South Region, Katherine Skiles

Biological and Agricultural Engineering Undergraduate Honors Theses

Rice grown in 5 states across the Mid-South (AR, LA, MS, TX, and MO) account for nearly 80% of all domestic U.S. rice production. Methane emissions produced during rice farming and the large seasonal water demand to maintain flooded fields have created a need for alternative irrigation research that can reduce methane emissions and conserve water. Structures called eddy covariance towers (ECTs) can observe methane and other flux responses to changing irrigation styles, and their data is shared across flux tower networks such as Delta-Flux in the Mid-South. The Delta-Flux network is relatively new, and its data-sharing capacity is not …

A Comparison Of Optical Measurement Methods For The Growth Of S. Cerevisiae, Jackson Black

Chemical Engineering Undergraduate Honors Theses

Genetic engineering of living organisms provides the opportunity to express and harvest different proteins from cell surfaces. Yeast (S. cerevisiae) is one such organism and is capable of being grown on an industrial scale. Cellular concentration is an important parameter to monitor while fermentation processes are underway, in order to control the environment inside the growth medium and maximize yields. Spectrophotometry is a conventional method for measuring concentration, but is limited by a narrow absorbance range, and the need for on-site periodic sampling. A continuous method of measurement, as provided by Bug Labs BE2100 non-invasive biomass monitor, would …

Automation Of Life Cycle Assessment, Jacob Hickman

Graduate Theses and Dissertations

An automation program, named Jacob LCA, was created to help perform life cycle assessment (LCA). The program uses a template file to perform controlled and consistently ordered actions with the LCA program, SimaPro, and effectively removes the need for manual user input. It can be set to run using data from one or more life cycle inventory (LCI) files, which allows for rapid iteration and testing of data. It also partially addresses some of the limitations of LCA by establishing a procedure through which temporal and spatial variations in data can be integrated into LCI files and then passed to …

Preparing Homogenous Composites Of Collagen And Cellulose Nanocrystals For Tissue Engineering Research, Zachary Stanley

Biological and Agricultural Engineering Undergraduate Honors Theses

Advancements in medicine and our understanding of stem cells have led to a greater emphasis on further developing research focused on tissue engineering. This research has led to the rise of both two-dimensional and three-dimensional scaffolds that can be utilized to repair bone, skin, vascular, and potentially even nervous tissue. One of the prominent compounds used in modern scaffolds is collagen-based hydrogels due to their low antigenicity and ability to provide structure to cells. There is potential to further improve upon this three-dimensional scaffold by incorporating cellulose nanocrystals (CNCs) into a composite hydrogel with collagen. The addition would increase the …

Evaluation Of Cellulose Nanocrystal Inks And Their Structural Characteristics For 3d Bioprinting Of Customized Scaffolds, Patrick William Kuczwara

Graduate Theses and Dissertations

3D bioprinting of biological scaffolds requires control of the physicochemical properties of each unique structures. A promising material for control of properties is hydrogels, which can help create biomimetic scaffolds with controlled spatial arrangement of materials by integrating biological materials directly into layers during the bioprinting process. Nanocellulose offers a unique combination of properties including mechanical, biomimetic, and biocompatibility. These properties offer flexibility over the types, shapes, and applications of their printed hydrogel scaffolds, (i.e., tissue, drug, encapsulation). However, 3D bioprinting of nanocellulose-based hydrogels requires high loading percentages (i.e., >10 wt%) or chemical crosslinkers (i.e., bis(acyl)phosphane oxides (BAPO)). High solid …

Modeling The Impact And Accelerating The Process Of Transitioning To A Sustainable Healthy Diet Through Decision Support Systems, Prince Agyemang

Graduate Theses and Dissertations

Food production and consumption are essential in human existence, yet they are implicated in the high occurrences of preventable chronic diseases and environmental degradation. Although healthy food may not necessarily be sustainable and vice versa, there is an opportunity to make our food both healthy and sustainable. Attempts have been made to conceptualize how sustainable healthy food may be produced and consumed; however, available data suggest a rise in the prevalence of health-related and negative environmental consequences of our food supply. Thus, the transition from conceptual frameworks to implementing these concepts has not always been effective. This paper explores the …

Cyanobacterial And Microcystin Response To Nutrient Additions At Lake Fayetteville Throughout The 2021 Growing Season, Lillie Haddock

Graduate Theses and Dissertations

Harmful Algal Blooms (HABs) are becoming a global concern due to their increasing distribution, frequency, intensity, and the occurrence of toxins. While it is known that eutrophication influences algal blooms, there is less known about what triggers these HABs to produce toxins, especially microcystin. In this study, we conducted 21 community bioassays at Lake Fayetteville, a hypereutrophic reservoir in Fayetteville, Arkansas, from April-November 2021 to examine how the addition of phosphorous and nitrogen influence cyanobacteria concentrations, microcystin concentrations, and microcystin toxin production. These experiments included a control, nitrogen (1.0 mg/L as KNO3), low phosphorus (0.025 mg/L as K2HPO4), high phosphorus …

An Engineering And Economic Analysis Of The Implementation Of The Carbo Rock-It, Lydia Huck

Graduate Theses and Dissertations

The patented Carbo Rock-It system was developed to carbonate beverages for the craft brewing industry with the goal of reducing time, cost, and environmental impacts of the carbonation process. This research field tests, models, analyzes and optimizes the engineering and economic performance of a commercial-scale Carbo Rock-It placed in production at an operating brewery (Core Brewing and Distilling Co., Springdale, AR). Field tests indicated that the Carbo Rock-It was able to successfully carbonate twelve 120 BBL batches of Scarlet Letter Seltzer to 3.0 vol/vol while meeting all beverage quality and safety requirements. The Carbo Rock-It was able to reduce carbonation …

Modeling Leaf Area Index And Canopy Height Using Growing Degree Days, Ellie J. Kuhn

Biological and Agricultural Engineering Undergraduate Honors Theses

As the global population increases and food security is recognized as a critical issue, crop growth prediction models help ensure the sustainability of reliable food sources. Using a prediction model based on temperature and simple, measurable field parameters, e.g., Leaf Area Index (LAI) or Canopy Height (H_can), may allow farmers and others to intervene mid-season with fertilizer, irrigation, or other inputs to obtain a better harvest.

This study aims to create a general model that could predict LAI and H_can values for numerous rice varieties using Growing Degree Days (GDD) as the time scale. The models use …

Development Of An Equation To Correlate Brite Tank Temperature And Pressure To Beverage Carbonation Concentration, Devyn Meyer

Biological and Agricultural Engineering Undergraduate Honors Theses

The Carbo Rock-It™ is an invention created to carbonate beverages at craft breweries. One of the Carbo Rock-It’s main features is that it does not add a significant volume of undissolved gas bubbles to the brite tank in which the beverage is carbonated. This may allow temperature and pressure readings from the brite tank to be used to determine the concentration of dissolved carbon dioxide in the beverage continuously in real time. This eliminates the need for manual samplings, which could save breweries time and allow for more controlled, accurate carbonation. The goal of this project was to develop an …

Atomic Force Microscopy Based Dna Sensing And Manipulation, Matthew Shubert

Mechanical Engineering Undergraduate Honors Theses

Sequencing DNA provides a positive impact for the biomedical community by understanding a wide variety of applications such as human genetics, disease, and pathogens. The reason the Arkansas Micro & Nano Systems lab is involved with research in DNA sequencing is due to the current, leading industry method. Nanopore sequencing was developed by Oxford Nanopore Technology in which its sequencing method separates double stranded DNA to electrically characterize individual nucleotides traveling through a charged nanopore. Unfortunately, nanopore sequencing uses biological materials that require a shelf life and drives high cost. Therefore, the Arkansas Micro & Nano Systems lab has developed …

Exploring The Effects Of Varied Land Use On Elemental Concentrations Within Streams, Logan Jennings

Biological and Agricultural Engineering Undergraduate Honors Theses

It is well documented that human activity influences the chemistry of surrounding waters. As such, it is possible that there is a link between land use within a watershed and the chemical composition of the stream. The objectives of this study are to determine if varied land use does affect the concentrations of macronutrients and trace elements present in the streams of Northwest Arkansas, and if so, to determine what extent urban and agricultural development are responsible for these changes. Water samples were collected across 19 streams in the Northwest Arkansas region between January and March of 2022. Water samples …

Greenhouse Tomatoes: Process Simulation, Juan Gabriel Marin Jr.

Graduate Theses and Dissertations

Growing population demand and challenges brought on by climate change have spurred the need for more resilient fruit and vegetable supply chains. One agricultural technology of significant interest is the use of greenhouses for food production. Greenhouses create a stable and adaptable environment for crops such as tomatoes to grow year-round. Fresh tomatoes are the second most consumed vegetable per capita in U.S. diets, currently averaging 20.7 pounds. The growing consumption of fresh tomatoes has been the result of increasing cultural diversity in the United States.

To meet the growing demand, Venlo-type greenhouses have been frequently used by growers. It …

Evapotranspiration In Mid-South Rice Production, Colby Wade Reavis

Graduate Theses and Dissertations

Rice provides much needed sustenance to a large portion of the global population, particularly in the developing world. With stress placed on food production systems under the reality of climate change and an increasing global population, rice production systems require solutions to a number of issues, including a limited water supply. As producers explore new strategies for conserving local water resources to continue to maintain yields, new irrigation strategies and technologies are being developed and validated for use at commercial production scales. Alternate wetting and drying (AWD) is an irrigation practice that provides water savings through the capture of rainfall …

Effect Of Hydrogen Peroxide On Algae And Microcystin In Control And Lake Waters, Tatiana Castillo Hernandez

Biological and Agricultural Engineering Undergraduate Honors Theses

Cyanobacteria are photo-autotrophic organisms with a worldwide distribution, which can result in Harmful Algal Blooms (HABs) producing toxins. One of the most common strains of cyanobacteria is Microcystis, which produces the most abundant cyanotoxin, microcystin. In this study, we analyzed the effect of H₂O₂ on algae and microcystin using both lake and reagent grade water. The first objective was to determine the effect of H₂O₂ on algae and cyanobacteria in lake water that was nutrient enriched. The second objective was to detect the effect of H₂O₂ at oxidizing microcystin in …

A Portable Point-Of-Care Device Using Joule Heating And Latent Energy Storage For The Temperature Regulation Of Isothermal Nucleic Acid Amplification Tests, Aubrey Lynn Schultz

Graduate Theses and Dissertations

Accurate and early diagnosis of infectious diseases extremely important. Rapid diagnosis allows for effective treatment and increases the chance for recovery without complications. Additionally, the ability to test the populace frequently, swiftly, and affordably significantly aids in containing wide-scale outbreaks. In terms of specificity and sensitivity, nucleic acid amplification tests (NAAT) are one of the best options for diagnosing infectious diseases. Isothermal NAATS present a unique opportunity to create diagnostic tests deployed at a Point-of-Care (POC) level. Specifically, loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA) have the potential to deliver reliable POC diagnostics in low-resource settings. When designing …

Nanomaterial-Based Biosensors For Detection Of Salmonella Typhimurium And Avian Influenza Virus H5n1 In Poultry, Xinge Xi

Graduate Theses and Dissertations

This research focused on developing biosensing method and biosensing device for rapid detection of pathogens in poultry: Salmonella Typhimurium and avian influenza virus H5N1. The first part of the dissertation reports an original research on the development of a portable biosensing device for Salmonella detection. The device was designed and constructed based on a previously developed optical biosensing method, using immuno-magnetic nanoparticles to specifically capture target bacteria, and immuno-quantum dot beads to label the target bacteria for fluorescence detection. All the actions of sample mixing, magnetic separation, and fluorescence detection were controlled automatically in a disposable microfluidic chip in the …

Evaluating The Effects Of Wood Source On The Physicochemical Properties Of Crosslinked Cellulose Nanocrystals, Helena Tchoungang Nkeumen

Graduate Theses and Dissertations

Cellulose is an abundant and naturally occurring biopolymer that has been used by humans for food, shelter, and clothing for about two centuries now. Highly crystalline nanoparticles derived from cellulose, called cellulose nanocrystals (CNCs), show great potential to meet the rising need for sustainable and nontoxic materials for biomedical applications. However, multiple biomedical applications of CNCs, such as those involving their use in tissue engineering scaffolds, require CNC-based structures to be stable in aqueous environments, a property that native CNCs do not possess due to their inherent hydrophilicity. Chemical crosslinking of CNCs addresses this issue by providing aqueous stability to …

Performance And Economics Of Solar Inverters And Module Level Power Electronics In A 1 Mw Photovoltaic System, Maxwell Criswell

Biological and Agricultural Engineering Undergraduate Honors Theses

Photovoltaic solar panels convert sunlight to electricity in the form of direct current; therefore, a necessary component of every photovoltaic system is an inverter to convert the electricity to usable alternating current. There are various commercially available inverter technologies manufactured today such as microinverters, string inverters, and central inverters, as well as module level power electronic devices such as DC optimizers that are capable of improving system performance in string and central inverter systems. This thesis compares the performance and economics of five different inverter and module level power electronic systems through model simulation using Helioscope software. The five alternatives …

Design Of Control Logic And The Human-Machine Interface For A Demonstration Plant Growth Chamber Implemented On A Programmable Logic Controller, Rachael Koehler

Biological and Agricultural Engineering Undergraduate Honors Theses

This honors thesis covers the planning, development, and implementation of system controls and human-machine interface (HMI) for a demonstration plant growth chamber. The work is a continuation of an ongoing project to be used as an educational and recruiting tool manifesting the skills acquired from the Biological and Agricultural Engineering Department at the University of Arkansas’ College of Engineering. This work includes emergency controls, overall design interface, and controls for both the aeration and lighting subsystems of the growth chamber. Overall design interface controls established included development of two user modes, Administrator and Visitor. The Administrator user will have full …

Projecting Water Available For Irrigation Use And Identifying Water Supply Stress Under Climate Change Scenarios In Selected U.S. Fruit And Vegetable Production Regions, Andrew Shaw

Graduate Theses and Dissertations

Climate change affects water resources differently across geospatial regions in the United States (U.S). There is a concern of how water availability will be affected by changes in long-term temperature and precipitation patterns, specifically in major production regions for eight fruit and vegetable crops. The effects on surface water available for irrigation use and supply stress in five regions containing 31 Agricultural Statistics Districts (ASDs) were assessed. The Water Supply Stress Index Model was used and modified to project water available for irrigation use across nine climate scenarios driven by historical data, five General Circulation Models, two population scenarios, and …

An Impedimetric Aptasensing System For The Rapid Detection Of Salmonella Typhimurium, America Sotero

Graduate Theses and Dissertations

Salmonella Typhimurium is a foodborne pathogen associated with raw and undercooked eggs, poultry, beef, fruits, and vegetables. In the United States, Salmonella is responsible for approximately 1.2 million illnesses, 23,000 hospitalizations, and 450 deaths annually. For many years, conventional detection methods such as culture-dependent and PCR-based methods have been the “golden standards” for the detection of this pathogen due to their high sensitivity and reliability. However, they still have some disadvantages such as long enrichment steps and high costs that need to be overcome. The development of a rapid and reliable method for the detection of S. Typhimurium is needed …

The Effects Of Solution Condition On Virus Filtration Performance, Fnu Namila

Graduate Theses and Dissertations

Virus filtration is an integral part of the downstream purification of mammalian cell culture-derived biotherapeutics to assure the viral safety of the products. Virus filtration membranes remove viruses based on a size-exclusion mechanism. Commercial parvovirus filers possess unique membrane structure and are designed to remove smaller non-enveloped parvoviruses with size 18-26 nm. However, some filters face issues, such as pre-mature fouling, the decline of filtrate flux, and reduction in virus retention. This doctoral dissertation focused on identifying the factors that influence the filtrate flux and the virus retention capability of commercial virus filters. The effects of solution pH and ionic …

Ventilation And Recirculation Airway Design For An Autonomous, Climate Controlled, Hydroponic Demonstration Unit, Nicholas Cross

Biological and Agricultural Engineering Undergraduate Honors Theses

For this Honors Thesis project, I designed and fabricated a ventilation and recirculation airway sub-system prototype for a hydroponic demonstration unit to be used as an educational demonstration for prospective students, illustrating the capabilities of biological engineers. This thesis focuses on the design of an autonomous air system that toggles between ventilation and recirculation modes based upon sensor output. In the literature review I discuss how ventilation can be used to achieve a targeted climate, the benefits of hands-on projects for education, and the optimum parameters for growing herbs in a hydroponic system.

In the design and fabrication process, every …

Comparing Economics Of Traditional Carbonation Method And A Novel Carbonation Invention For Craft Beer, Kira Simonson

Biological and Agricultural Engineering Undergraduate Honors Theses

The traditional method for the carbonation of beer includes bubbling CO₂ through a pressurized brite tank until the desired level of carbonation concentration is reached. The gas either dissolves in the liquid volume or passes through the beer into the gas headspace above the bulk volume of beer. The gas that passes through the liquid can strip the beer of flavors, and this undissolved gas is vented to the atmosphere. To reduce the gas lost to the atmosphere, the CO₂ is dissolved into the beer slowly over a long period of time, which increases gas-use efficiency but sacrifices …

Design Of A Deep Flow Technique Hydroponic System And An Elementary Education Module For Tri Cycle Farms, Cady Rosenbaum

Biological and Agricultural Engineering Undergraduate Honors Theses

Hydroponics is an agricultural technique in which plants are grown without soil and are instead grown in water systems that include nutrients and other growth-supporting media. Hydroponic systems typically reside inside, so that the system can be fully controlled by the grower by manipulating the temperature and amount of light the plants receive. The benefits of growing plants using hydroponics include: the amount of water used is reduced, it is less labor to grow organic produce with an indoor system, less space used, and it allows for growing food anywhere. Tri Cycle Farms is planning for the construction of a …

Cell Line-Specific Differences In Guided Differentiation Of Adipose-Derived Mesenchymal Stem Cells Towards Smooth Muscle Cells, Sherly Makar

Biomedical Engineering Undergraduate Honors Theses

Mesenchymal stem cells (MSCs) are a population of stromal cells found traditionally in the bone marrow and adipose tissues. They can also be found in other tissues including fallopian tube, core blood, peripheral blood, fetal liver, and lungs. Mesenchymal stem cells have profound effects in regenerative engineering, tissue repair and drug discovery owing to the excellent properties such as proliferation, self-renewal, and multipotency generating multiple cell types including adipocytes, osteocytes, cardiomyocytes (CMs), pericytes (PCs), and chondrocytes. MSCs are used as immunomodulators in generating progenitor cells to be used for transplantation, creating engineered organs, and preventing graft vs. host disease (GVHD). …

A Study Of Protein And Peptide-Directed Nanoparticle Synthesis For Catalytic Materials, Abdollah Mosleh

Graduate Theses and Dissertations

Nanoparticles have received much attentions due to their unique properties that makes them suitable candidates for a broad range of applications. As the size of particles decreases, their surface area-to-volume ratio would increase which is the main cause of much attention. In addition to the size, their morphologies and compositions may also play important roles for defining unique properties. Nanoparticle synthesis include both bottom-up and top-down strategies. To control the process of inorganic nanoparticles synthesis one could follow the bottom-up approach to have atom-level control over their compositions, morphologies, phases, and sizes which is the subject of this work. Due …

Visualizing Ischemic Skin Flap Necrosis Through Phasor Analysis Of Autofluorescence Lifetime Images, Hallie Ramser Toomer

Graduate Theses and Dissertations

Necrotic skin flaps are difficult to predict and treat due to the lack of quantitative biomarkers. Label-free multiphoton microscopy is well suited for non-invasively monitoring skin metabolism through NAD(P)H and other intrinsic fluorophores, and offers immediate future directions for assessing necrosis in the clinic. The objective of this study was to assess whether phasor FLIM could be used to evaluate skin flap status and treatment efficacy in ex vivo skin sections. Phasor maps revealed differences in growth factor treatment and region, but changes in skin flap autofluorescence at 755nm excitation and 460nm emission were not just related to NAD(P)H. A …

Volumetric Muscle Loss: The Role Of Physical Activity And Autologous Repair On Force Recovery And Signaling Pathways, Richard Perry

Graduate Theses and Dissertations

Volumetric muscle loss affects both military and civilian persons. The hallmark of this injury is incomplete muscle regeneration, excessive fibrosis, and chronic inflammatory signaling resulting in permanent functional loss. Since permanent functional loss drastically reduces quality of life, many studies have been conducted to improve force recovery. Current scientific literature considers a repair strategy of either devitalized scaffolds infused with growth factors or viable tissue plus activating factors to be the more promising interventions for optimal force recovery. PURPOSE The purpose of this study is to incorporate autologous repair and physical activity and observe the effects of muscle force recovery …