Bioresource and Agricultural Engineering Commons^™

Phosphorus Flux From Bottom Sediments In New Spiro Lake, Oklahoma, Katherine Smith

Biological and Agricultural Engineering Undergraduate Honors Theses

Phosphorus loads to water bodies consist of external flux from the watershed and internal flux from the bottom sediments. In this study, the specific objectives were to measure the internal phosphorus flux from bottom sediments under aerobic and anaerobic conditions and determine the effectiveness of various rates of alum treatment on sediment phosphorus release. Eight intact sediment cores from New Spiro Lake were incubated under aerobic and anaerobic conditions for 41 days at room temperature. The cores were treated in the middle of incubation with alum (aluminum sulfate) and sodium aluminate at a ratio of 2:1, ranging from 0.05 to …

Potential For Optical Sensor-Based Nitrogen Fertilization In Grain Sorghum (Sorghum Bicolor L. Moench) In Arkansas, Kamil H. Rosales Rodriguez

Graduate Theses and Dissertations

Ground-based active-optical (GBAO) crop sensors have become an effective tool to improve nitrogen (N) use efficiency and to predict yield early in the growing season, particularly for grass crops. Commercially available canopy sensors calculate the normalized difference vegetative index (NDVI) by emitting light in the red and near infrared range of the electromagnetic spectrum. The NDVI is used to evaluate vigor status and to estimate yield potential. However, few studies have been conducted to compare the performance of commercially available sensors. Therefore, a study was conducted using the most common crop canopy sensors: i) N-Tech's GreenSeeker^TM (GS), ii) Holland …

Evaluation Of Broiler Litter Heat Production During Windrowing & Nitrogen Based Gas Emission Mitigation Using Biofilter, Min Lei

Graduate Theses and Dissertations

Ammonia emission from animal feeding operations (AFOs) has negative effects on environment and animals' health. Thus measuring and mitigating ammonia emission from AFOs is important for environmental protection. In chapter I, different ammonia measurements were discussed and a mitigation technology- biofilter was represented.

In-house windrowing of built-up litter has been used by broiler producers to reduce pathogen loads and rejuvenate litter for the next flock. When litter is piled up for an extended period during downtime, heat generated by the litter pile can become a substantial heat source due to the metabolism of microorganisms. In chapter II, heat production rates …

Characterization And Quantification Of Monomers, Oligomers, And By-Products From Switchgrass Hemicelluloses During Biomass Pretreatment, Kris Allan Bunnell

Graduate Theses and Dissertations

Production of fuels and chemicals from biomass is contingent upon economical release of carbohydrates from biomass. Carbohydrates can then be used for production of bio-based products using a biochemical conversion process. Pretreatment, the first step of the biochemical conversion process, has been suggested to be the most costly step of the conversion process. Thus, better understanding the behavior of biomass during pretreatment is imperative for an economically viable production of biofuels and chemicals. Elucidating the physicochemical properties of biomass and developing an understanding the depolymerization patterns of biomass during pretreatment will help progress towards this goal.

In this study, July- …

A Cradle To Farm Gate Life Cycle Analysis Of Water Use In U.S. Pork Production, Eric Boles

Graduate Theses and Dissertations

The intent of this study was to analyze water use across a range of regions, scales and practices of the U.S. pork industry. A Life Cycle Assessment of water use within the pork supply chain was performed. Cumulative water use was the environmental impact category used in the LCA to evaluate the impacts of pork production processes throughout the pork supply chain. The functional unit for the analysis was the volume of water required to produce one kilogram of swine (live weight) at the farm gate.

A comprehensive literature review was used to design and propagate algorithms for the National …

Minimizing Wash Water Usage After Acid Hydrolysis Pretreatment Of Biomass, Noaa Frederick

Biological and Agricultural Engineering Undergraduate Honors Theses

Abstract Dilute acid pretreatment, needed to prepare biomass for saccharification, results in the production of a number of byproducts, which inhibit subsequent enzymatic hydrolysis and fermentation steps. In order to improve saccharification yields in the enzyme hydrolysis step, the pretreated biomass is often rinsed with room temperature water to remove these byproducts. High-density poplar was pretreated with 1% dilute sulfuric acid at 140 ºC for 40 minutes. After pretreatment the biomass was washed with water volumes equal to 0, 1 ½, or 3 times the biomass volume. The rinsed biomass was then enzymatically hydrolyzed and the concentrations of byproducts and …

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. …

Evaluation Of Rice Hulls As A Lignocellulosic Substitute In Wood Plastic Composites, P. Jack Bourne

Inquiry: The University of Arkansas Undergraduate Research Journal

Rising raw material costs and shortage of woody materials necessitate alternative sources for lignocellulosic material in wood plastic composites (WPC). This study was conducted to evaluate rice hull (RH), an agricultural residue, as a cellulosic substitute in WPC. Samples were fabricated with approximately 4% zinc stearate, 48% high-density polyethylene obtained from recycled plastics and 48% lignocellulosic material by mass. The composition of the lignocellulosic material was changed from 0 to 100% RH at 20% increments while the remainder was wood flour. The extruded sampled were tested for mechanical properties such as specific gravity, water absorption, linear coefficients of thermal expansion, …

Extraction Of Silymarin Compounds From Milk Thistle (Silybum Marianum) Seed Using Hot, Liquid Water As The Solvent, J.F. Alvarez Barreto

Inquiry: The University of Arkansas Undergraduate Research Journal

High value specialty chemicals are usually obtained from natural products by extracting with generally regarded as safe (GRAS) solvents. Because organic solvents are quite often used, high operating and disposal costs often occur. When compared to traditional solvents, water can be viewed as an interesting alternative because of its low operating and disposal costs. Milk thistle contains compounds (taxifolin, silychristin, silydianin, silybinin A and silybinin B) that display hepatoxic protection properties. This paper examines the batch extraction of silymarin compounds from milk thistle seed meal in 50'C, 70'C, 85'C and 100'C water as a function of time. For taxifolin, silychristin, …