Biological Engineering 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 …

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 …

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 …

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 …

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 …

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 …

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 …

Assessing Commonly Used Methods In Measuring Yield Of Cellulose Nanocrystals, Marilyn Pharr

Biological and Agricultural Engineering Undergraduate Honors Theses

Cellulose is a ubiquitous, renewable biopolymer found in plants that can be broken down to isolate cellulose nanocrystals (CNCs). CNCs have been utilized in various applications that include biomedical technology, structural composites, and barrier films because of their unique mechanical, optical, and physicochemical properties. CNCs can be produced by a variety of approaches from cellulosic materials; however, strong acid hydrolysis is the most common and effective technique as it results in stable colloidal suspensions. Existing literature reveals a wide range of CNC yields, depending on the production process, raw material used, and the method of yield estimation. The yields of …

Ecological Co2 Flux Of A Green Roof Ecosystem And A Typical Grassland Ecosystem, Madeline Oxner

Biological and Agricultural Engineering Undergraduate Honors Theses

The Hillside Auditorium Green Roof is a low impact development feature on the University of Arkansas campus. It retains storm water and allows plants living on the roof to take up and transpire the water. Green roofs work to mimic natural ecosystems in urban environments. A key property is ecosystem respiration, which plays a large role in the global carbon cycle and is an important biologic activity indicator. The ecosystem respiration of Hillside Auditorium Green Roof was compared to a typical grassland ecosystem at the University of Arkansas farm to determine how closely the green roof is able to mimic …

Nutrient Limitation Of Algal Growth In Fishery Lakes, Madeline Ludwig

Biological and Agricultural Engineering Undergraduate Honors Theses

This study investigated the effect of nutrient addition on algal growth in three United States Forest Service lakes for fishery management in Arkansas. In fishery managed lakes, fertilization works by manipulating algae growth, a basal food resource in lakes, to promote the growth of the fish population. For the nutrient addition experiments, water was collected from each lake in cubitainers and spiked with nutrients; the treatments included the control, nitrogen (+N), phosphorus (+P), and nitrogen and phosphorus (+N +P). When algal growth was visually observed, a water sample was collected from each cubitainer and analyzed for chlorophyll-α. The results showed …

In-Cage Surface Wetting System For Cooling Poultry In Transport, Ryan Clark

Biological and Agricultural Engineering Undergraduate Honors Theses

Abstract

Poultry health and mortality rates are important considerations in poultry production, as companies can minimize product loss and appeal to a consumer base whose concern for animal welfare continues to grow. Although animal welfare is a consideration for the entire poultry production process, this project focuses on the live-haul phase of the process, specifically during transport from grow houses to processing facilities. During the summer months, broiler chickens being transported can suffer from heat stress that can lead to death. This project consists of the designing and testing of an in-cage surface wetting system to minimize heat stress incidents …

Optimizing Genetic Manipulation Of Methanogens Through Faster Cloning Techniques, Merrisa Jennings

Biological and Agricultural Engineering Undergraduate Honors Theses

Methanogenesis is the biological production of methane. Only anaerobic archaea known as methanogens are capable of such a metabolic feat. They have strict living conditions and substrate sources which determine their rate of metabolism. This is of particular importance from a greenhouse gas reduction perspective or biogas capturing perspective. One of the best ways to optimize methanogen methane production is via genetic manipulation. The current procedures are timely though, therefore a faster cloning processes should be developed. The objective of this study was to optimize a premade genetic transformation kit known as the Gibson Kit. The Gibson Kit was supposed …

Effect Of Storage Temperature And Time On Lyophilized Water Bark Extract's Biological Activity, Jillian Schneider

Biological and Agricultural Engineering Undergraduate Honors Theses

Sweetgum bark extract has been known to show biological activities such as antimicrobial and antioxidant capabilities. The storage capacity of the extract, however, was unknown and previously thought to diminish over time. However, upon experimentation, the freeze-dried sweetgum bark extract showed no signs that storage time or storage temperature had any significant effect on the biological activities. There was no significant difference across storage temperature over time in the experiment (ANOVA RM, P0.05). Therefore, the antioxidant capabilities of the sweetgum extract were not affected by the storage time or temperature treatments studied in this work. For the antimicrobial experiment, there …

Municipal Composting And Organic Waste Diversion: The Case Of Fayetteville, Arkansas, Michael E. Hoppe

Biological and Agricultural Engineering Undergraduate Honors Theses

It is estimated that 40% of food is wasted in the United States; representing $165 billion in wasted resources. A vast majority of that wasted food is ultimately placed in landfills where it decomposes and releases harmful greenhouse gases (GHGs). In fact, food waste alone is responsible for 23% of annual methane emissions for the US. This has a huge impact on global climate change due to the potency of methane as a greenhouse gas. Currently only 5% of the food waste produced is recovered across the nation. Source reduction would be the best solution to reducing this food waste, …

Aquatic Bacteria Removal Using Carbon Nanotubes, Suvish Melanta

Biological and Agricultural Engineering Undergraduate Honors Theses

The purpose of this project is to explore the functionality of carbon nanotubes as a bacterial removal method, specifically towards water-borne bacterial pathogens in wastewater by utilizing its unique magnetic and bacteria-binding properties. The general protocol set for this research follows five steps: 1) Preparation of wastewater media, 2) preparation of CNT culture, 3) preparation of reaction mixture with CNTs for bacterial binding, 4) magnetic separation of bacteria-bound-CNT clusters and, 5) assessment of supernatant. The CNTs effectively removed bacterial contaminants in the wastewater (10%, v/v) after the sand filtration process from the Paul R. Noland Wastewater Facility at Fayetteville, Arkansas. …

Computational Modeling Of Oxidative Stress: An Analysis Of Nad (P)H Effects On Nitric Oxide And Superoxide During Hypertension, Aaron Strobel

Biological and Agricultural Engineering Undergraduate Honors Theses

Nitric oxide (NO) is inactivated in the human body when exposed to superoxide (O2 -). This reaction forms peroxynitrite (ONOO-). Superoxide is produced in the cardiac system by several different ways, including NAD(P)H oxidase. Superoxide dismutase (SOD) breaks down superoxide into oxygen and hydrogen peroxide. This prevents superoxide from reacting with nitric oxide and allows normal function to take place. Superoxide and peroxynitrite are main contributors to vascular disease in the human body, in particular hypertension. Experiments have shown that there was an increase of superoxide production in spontaneously hypertensive rats (SHR) vs. age-matched Wistar Kyoto rats (WKY) that were …

The Effect Of Water Extracted Silibinin On Reactive Oxygen Species (Ros) Production Of Macrophages, Julie Abbott, Sunny Wallace, Ed Clausen, Danielle Carrier

Biological and Agricultural Engineering Undergraduate Honors Theses

The world is actively looking for technology to produce sustainable liquid fuels to replace our reliance on petroleum-based fuels. Biomass can be converted either through the thermochemical or saccharification platforms into fuels such as ethanol or butanol. In addition to converting the biomass into liquid fuels, valuable phytochemicals can be extracted prior, during, or after the conversion. Extracting useful phytochemicals, as a part of the overall conversion of biomass to fuels, is included in the concept of the biobased biorefinery. However, the key to effectively and economically extract phytochemicals from biomass is the ability to couple the extraction to the …