Engineering Commons^™

Examining The Relationship Between Manning's Roughness Coefficient And Stage, Henry Holtkamp

Biological and Agricultural Engineering Undergraduate Honors Theses

This paper uses LOESS regression to predict Manning's roughness coefficient to calculate flows in natural stream channels. Manning's roughness coefficient can introduce variability into Manning's equation, potentially destabilizing results. Utilizing LOESS to find n based on backcalculated n from collected discharge vs. stage information is the best way to acquire accurate Manning's roughness coefficient values at a variety of flows. Book values tend to drastically overestimate which can have wide-ranging implications for water allocation, flood management, maintaining environmental flows, and maintaining water quality.

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 …

Analyzing Energy Use From Arkansas Public School Buildings, Oscar Morton

Biological and Agricultural Engineering Undergraduate Honors Theses

Energy is a key global resource in society and greenhouse gas (GHG) emissions related to the consumption of energy have detrimental effects on the planet. With energy consumption increasing, exponential population growth, and diminishing natural resources necessary for energy production, the relevance of energy efficiency is dramatically increasing. In this project, I analyzed energy usage data from a set of public school buildings from one school district in northwest Arkansas from 2018, before targeted energy efficiency practices were implemented, through 2022 to see if energy usage changed over this short period. The objectives of analyzing energy data were to determine …

A Snapshot Of Sars-Cov-2 In Wastewater Treatment Plants In Northwest Arkansas, Katie Loethen

Biological and Agricultural Engineering Undergraduate Honors Theses

Because SARS-CoV-2, a coronavirus, is released in the fecal shedding of covid-positive patients, the virus enters the municipal waste stream and flows to wastewater treatment plants (WWTPs). The goal of this research is to quantify the effectiveness of wastewater treatment processes at removing SARS-CoV-2 from wastewater and preventing its release into the environment. Sampling at Paul R. Noland and West Side WWTPs in Fayetteville, Arkansas, took place from August 2020 to May 2021, and samples were tested for the presence of SARS-CoV-2 using N1 and N2 primers via RT-qPCR. Sampling days which returned positive detection of one or both of …

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 …

Potato Processing In The Home: Sustainability And Nutritional Impacts, Aubin Payne

Biological and Agricultural Engineering Undergraduate Honors Theses

Potatoes are the world's fourth most consumed crop. Their versatility and long shelf-life make them a staple food for millions of people worldwide. Still, the increasing consumption of highly processed potato products in developed countries has damaged the public's appreciation of potatoes as a valuable source of essential nutrients. Additionally, as public awareness of environmental sustainability increases, the average consumer is more likely to value processing methods that mitigate environmental damage.

Researchers simulated several home storage and processing conditions to find out how nutrition and environmental impact are affected by the home processing timeline. Then, a nutrient analysis, life cycle …

Sensory Comparison Of Beer Carbonated Using Forced Carbonation And The Carbo Rock-It, Michala Smith

Biological and Agricultural Engineering Undergraduate Honors Theses

Craft brewing is a growing market which represents over 12% of beer produced in the United States. Dr. G Scott Osborn, PE invented the Carbo Rock-It™ to improve the carbonation process for craft breweries. The invention allows for shorter carbonation time and uses less CO₂, saving companies money and time. Because of the lack of gas losses through bubbling, Osborn theorized that the Carbo Rock-It could also prevent the “stripping of the nose” that can occur in traditional forced carbonation. Existing research supports the mechanism, as beer flavor and aroma volatiles have been detected during the release of …

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 …

Climate Change Impacts And Engineering Solutions, Dawson Oakley

Biological and Agricultural Engineering Undergraduate Honors Theses

With climate change entering the forefront of global issues, the need for sustainable practices that can provide for human welfare, social and economic development, and health has become more urgent than ever. Despite the recent increase in climate change impacts around the world, many people are still unaware of the severity of the situation. Changing public perception of these issues is the first step in enacting change and increasing accessibility to this information plays an important role.

Much of the information people consume today comes in the form of video, and it can be an effective tool to change knowledge …

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 …

Light Intensity Control For Plc-Based Hydroponic Demonstration System, Christian Hitt

Biological and Agricultural Engineering Undergraduate Honors Theses

In order to demonstrate a skill set obtained through the University of Arkansas Biological Engineering, a group of students and I developed a hydroponic system where plants could be grown in a chamber. System parameters such as air quality, irrigation, and lighting were controlled by a Programmable Logic Computer (PLC) and an array of sensors and actuators. Each student focused on a certain aspect of this system, mine being the lighting. Developing this system involved researching the relationship between light intensity and plant growth, designing a system to suspend the lights above the growth chamber, and develop a system to …

Low Impact Development: Low-Maintenance Design To Encourage Residential Adoption Of Sustainable Systems, Haley Ellis

Biological and Agricultural Engineering Undergraduate Honors Theses

Residential adoption of low-impact development (LID) technology can positively impact downstream watershed hydrology by reducing total volumetric discharge from the residential site. This reduction can provide economic, environmental, and social benefits for the residents as well as the community at large. Additionally, homeowners are often affected by stormwater related issues, like flooding or washout, that could be easily mitigated with a sustainably engineered LID structure or network. Engineering for sustainability often includes the blending of several objectives to provide greater overall benefit. This thesis compares the outflow characteristics of three low-maintenance residential LID design scenarios differing in rain garden soil …

Estimating Irrigation In Rice Fields With A Water Balance Approach, Kristen Trinh

Biological and Agricultural Engineering Undergraduate Honors Theses

Global food production must increase to meet the demand associated with increased population growth, so irrigation water use will continue to rise. Therefore, it is important to monitor water usage particularly when an irrigation flowmeter is unavailable. A field water balance was created for a selection of rice fields in East-central Arkansas under observation in 2018 and 2019. From those, irrigation inputs are deduced from the water balance alone. First, each field had sensors that collected water table level (WTL) data. Next, other water inputs and outputs such as precipitation and evapotranspiration (ET) were collected from two modeled sources. The …

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 …

Design And Testing Of A Multi-Depth Soil Temperature Sensor Array Intended As A Candidate Irrigation Scheduling Tool, Lillian Glaeser

Biological and Agricultural Engineering Undergraduate Honors Theses

A crucial measure in the advancement of water conservation and sustainable agricultural strategies is increasing efficiencies of irrigation systems. Because of the lack of availability of affordable, durable, and scalable soil moisture monitoring devices, this thesis proposes a low-cost, multi-depth soil temperature sensor array as a candidate for monitoring soil moisture content and guiding farmer’s irrigation scheduling. Propagation of diurnal temperature waves through soil is dependent on the thermal diffusivity of the soil, which can be determined by examining temperature waves at different soil depths. Thermal diffusivity is dependent on several factors, though, in undisturbed soil, water has the largest …

Irrigation Design In Montana: Accommodating Varying Water Accessibility Across The Continental Divide., John Garrett Lampson

Biological and Agricultural Engineering Undergraduate Honors Theses

The design work performed in this project was conducted over two summers (2018, 2019) of internship experience with the Natural Resources Conservation Service (NRCS) across the state of Montana. The first summer’s design work was based out of Glendive, MT, in Dawson County, approximately 50 kilometers from the North Dakota border. The second summer was in Missoula, MT, in Missoula County, near the Idaho border. The two areas differ significantly in topography, weather, and water availability with the main separating geographic influence being the Rocky Mountains.

This paper focuses on the design process and requirements for two farms located outside …

Providing Sustainable Power Through Renewable Energy For Developing Communities In Central America, Elizabeth Topping

Biological and Agricultural Engineering Undergraduate Honors Theses

Rural electrification through an expansion of the power grid into remote villages in Central America is a development that is still years away. Using renewable energy technology, access to electricity is available even in the most remote areas of the world. These individual power grids are also called “microgrids.” Creating microgrids in rural areas provides the people living there with access to power they did not have before. With this newfound access to power, these communities can expand their access to education, using computers or mobile devices. They can power lights, refrigerators, and other devices to continue development.

The design …

Simulating Soybean-Rice Crop Rotation And Irrigation Strategies In Arkansas Using Apex, Sam Carroll

Biological and Agricultural Engineering Undergraduate Honors Theses

Rice is one of the most prevalent and relied upon resources around the world. Despite such prominence, cultivation techniques for this crop are not perfect. Precise irrigation amounts and optimal crop rotations are still not completely understood. As the global population continues to grow and resources are depleted, maximizing the efficiency of cropping systems becomes more urgent. The goal of this study was to shed light on these questions using the Agricultural Policy/Environmental eXtender (APEX) model to simulate five fields in soybean-rice rotation in Arkansas. First, the model was calibrated to accurately represent the observed yields in the area. Then, …

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 …

Discovering Synergies Among Sustainable Rating Systems In Green Roof Analysis, Kanaan Hardaway

Biological and Agricultural Engineering Undergraduate Honors Theses

As awareness has grown of the impacts the built environment has on the natural environment and the human psyche, methods to create more sustainable living environment have been developed. Green infrastructure is well-known for its environmental benefits. Emerging literature suggests green infrastructure have aesthetic qualities conducive to mental restoration, as well. To analyze the multi-benefits of green infrastructure, a green roof is studied for its aesthetic qualities and its impact on LEED, SITES, and WELL certification. A questionnaire was administered to individuals on the University of Arkansas campus to quantify human perceptions and attitudes toward a green roof on a …

Reducing Dissolved Phosphorus In Stream Water May Not Influence Estimation Of Sediment Equilibrium Phosphorus Concentrations, Eleanor Henson

Biological and Agricultural Engineering Undergraduate Honors Theses

The potential for stream sediments to adsorb or release phosphorus (P) depends on the equilibrium P concentration (EPC), which is the water column P concentration where P is neither (net) adsorbed nor released from the sediments. Current methods of measuring EPC in streams include adding known P concentrations to stream water, mixing with fresh sediments, and allowing the mixture to reach equilibrium through P sorption. Sediment EPC is usually calculated as the x-intercept of the linear relationship between initial P concentrations and P absorbed by the sediments. However, the x-intercept is often an extrapolation past the known data set (i.e. …

Design Of A Shallow-Aero Ebb And Flow Hydroponics System And Associated Educational Module For Tri Cycle Farms, Julie Halveland

Biological and Agricultural Engineering Undergraduate Honors Theses

Tri Cycle Farms, whose main mission is to reduce food insecurity in their community, is a non- profit urban farm in Fayetteville, Arkansas. The “Tri” in their name refers to the three parts of their foundation: giving a third of their yield to volunteers, giving a third to local food pantries, and selling a third to sustain the farm and demonstrate the economy of local food production. They want to expand on the third part and have a vision of building a hydroponic greenhouse with the intention that it will create more crops to sell and give, as well as …

Hvac System Energy Audit For Leverett Elementary School, Connor Smalling

Biological and Agricultural Engineering Undergraduate Honors Theses

Leverett Elementary School is located in Fayetteville, AR. The school needs significant upgrades to its infrastructure. The Fayetteville Public School District has voted to pursue an Energy Services Performance Contract (ESPC) in order to finance the desired upgrades to Leverett Elementary, among other schools in the district.

The scope of this thesis was to perform an energy audit on the existing heating, ventilation, and air conditioning (HVAC) system. By using an energy modeling software, eQuest, the building and the existing base system were modeled to determine utility consumption. Three different HVAC system alternatives were analyzed against the base system by …

Drivers Of On-Farm Performance Of Irrigation Water Management Practices: Empirical Evidence From Eastern Arkansas, Jacob Askey

Biological and Agricultural Engineering Undergraduate Honors Theses

Unsustainable agricultural practices are putting a strain on freshwater supplies in many parts of the world. More efficient irrigation techniques are going to be critical to feed a growing population. Data from the 2016 Arkansas Irrigation Survey was used to assess the adoption of three Irrigation Water Management (IWM) practices: multiple inlet rice irrigation, tailwater recovery, and storage reservoirs. Results indicate that these practices do not always lead to reported pumping time reductions, a proxy for water use savings. Large variations in pumping time reduction are observed across producers for all three practices. A Tobit model was used to examine …

Design Of Remote Datalogger Connection And Live Data Tweeting System, Zachary Wofford

Biological and Agricultural Engineering Undergraduate Honors Theses

Low-Impact Development (LID) is an attempt to sustainably respond to the potential hazards posed by urban expansion. Green roofs are an example of LID design meant to reduce the amount of runoff from storm events that are becoming more intense and less predictable while also providing insulation to buildings. LID has not yet been widely adopted as it is often a more expensive alternative to conventional infrastructure (Bowman et. al., 2009). However, its benefits are apparent. The University of Arkansas Honors College awarded a grant to research the large green roof atop Hillside Auditorium. One part of this grant is …