Open Access. Powered by Scholars. Published by Universities.®

Bioresource and Agricultural Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 121 - 150 of 365

Full-Text Articles in Bioresource and Agricultural Engineering

Primitive Palms: A Density Study On The Impacts Of Harvesting Natural Materials For Construction Purposes On Sumak Allpa Of The Amazon Rainforest, Zachary Bull Apr 2019

Primitive Palms: A Density Study On The Impacts Of Harvesting Natural Materials For Construction Purposes On Sumak Allpa Of The Amazon Rainforest, Zachary Bull

Independent Study Project (ISP) Collection

In an effort to better understand how rural construction techniques affect a surrounding environment, this study combines a density test of the natural building materials used in the construction of a school on Sumak Allpa island of the Orellana Province in the Amazon basin of Ecuador. The focus of the study measures the density of the bamboo species Guadua angustifolia and the Panama hat plant Carludovica palmata on the island while noting a comprehensive compilation of the techniques and materials used in the building process. Using a mix of plots and transects, a comparison of harvested material to remaining material …


Design Of A Portable Biogas Purification And Storage System, Anikumar Kosna, Bade Shrestha Mar 2019

Design Of A Portable Biogas Purification And Storage System, Anikumar Kosna, Bade Shrestha

Faculty Research and Creative Activities Award (FRACAA)

The objective of this study is to propose and design a commercial portable purification and storage system to commercialize biogas (which mainly consists of 45 - 75 % of methane and 15 - 16% of carbon dioxide), produced from household/non-commercial biogas plants. The selection of purification process is based on the portability of the purification system.


A Theoretical Model Of Underground Dipole Antennas For Communications In Internet Of Underground Things, Abdul Salam, Mehmet C. Vuran, Xin Dong, Christos Argyropoulos, Suat Irmak Feb 2019

A Theoretical Model Of Underground Dipole Antennas For Communications In Internet Of Underground Things, Abdul Salam, Mehmet C. Vuran, Xin Dong, Christos Argyropoulos, Suat Irmak

Faculty Publications

The realization of Internet of Underground Things (IOUT) relies on the establishment of reliable communication links, where the antenna becomes a major design component due to the significant impacts of soil. In this paper, a theoretical model is developed to capture the impacts of change of soil moisture on the return loss, resonant frequency, and bandwidth of a buried dipole antenna. Experiments are conducted in silty clay loam, sandy, and silt loam soil, to characterize the effects of soil, in an indoor testbed and field testbeds. It is shown that at subsurface burial depths (0.1-0.4m), change in soil moisture impacts …


Potential Economic Impacts Of Allocating More Land For Bioenergy Biomass Production In Virginia, Thomas O. Ochuodho, Janaki R. R. Alavalapati, Pankaj Lal, Domena A. Agyeman, Bernabas Wolde, Pralhad Burli Feb 2019

Potential Economic Impacts Of Allocating More Land For Bioenergy Biomass Production In Virginia, Thomas O. Ochuodho, Janaki R. R. Alavalapati, Pankaj Lal, Domena A. Agyeman, Bernabas Wolde, Pralhad Burli

Forestry and Natural Resources Faculty Publications

The growing attention to renewable energy and rural development has created greater demand for production of biomass feedstock for bioenergy. However, forest growth rates and the amount of land in most existing forests may not be sufficient to sustainably supply the forest biomass required to support existing forest products industries and the expanding bioenergy industry. Additionally, concerns about agricultural land use competition have dampened expansion of biomass production on agricultural land base. One of the ways to meet the growing forest biomass feedstock demand for bioenergy production is by allocating currently marginal non-forested land for growing bioenergy feedstocks. In Virginia, …


The Effect Of Edge-Of-Field Nutrient Management Practices On Microbial Concentrations In Subsurface Drainage Water And The Associated Risk Of Antibiotic Resistance Dissemination, Sara Mardani Jan 2019

The Effect Of Edge-Of-Field Nutrient Management Practices On Microbial Concentrations In Subsurface Drainage Water And The Associated Risk Of Antibiotic Resistance Dissemination, Sara Mardani

Electronic Theses and Dissertations

Many in-field and edge-of-field management practices have been used to reduce nutrient loads from agricultural fields. The denitrification woodchip bioreactor (WB) is one edgeof- field management practice that has proven to be effective in removing nitrate from subsurface drainage water. The success in nitrate removal achieved with WBs has raised interest in expanding their capabilities for removing other agricultural pollutants, including phosphorus, by using other types of media like phosphorus-sorbing filters or combining these filters with woodchips to remove both nitrate and phosphorus as dual-nutrient removal systems. Despite the extensive research done on WBs and nutrient filter materials, little consideration …


Temporal Changes Of Nutrients Within The Lower Grand River Watershed And Selected Sites, Weston Scott Duley Jan 2019

Temporal Changes Of Nutrients Within The Lower Grand River Watershed And Selected Sites, Weston Scott Duley

Masters Theses

"This report presents the results of a study carried out in collaboration with the U.S. Geological Survey (USGS) and the Missouri Department of Natural Resources (MDNR) to estimate total nitrogen (TN) and total phosphorus (TP) at five USGS monitoring sites within Lower Grand River Watershed (LGRW) and two monitoring sites on the Missouri River. The objective of this study was to quantify temporal changes in TN and TP concentrations and compare those to best management practices (BMPs).

In this study, the approach to the analysis of long-term surface water-quality data by using Weighted Regressions on Time, Discharge and Seasons models …


Variability Of E. Coli In Streambed Sediments And Its Implication For Water Quality, Sadia Salam Jan 2019

Variability Of E. Coli In Streambed Sediments And Its Implication For Water Quality, Sadia Salam

Electronic Theses and Dissertations

Fecal indicator bacteria (FIB), including E. coli, are the number one cause of water quality impairments in the United States according to the USEPA. FIB are used as a predictor to identify the possible presence of pathogens in waterbodies. E. coli is a useful indicator of gastrointestinal (GI) related illnesses from contact with fresh water. While surface water is routinely monitored for water quality, streambed sediments are rarely considered as a source of FIB to the overlying water column. This study focuses on understanding the variation of E. coli concentrations in streambed sediments and the potential impact of sediment sources …


Identifying Advantages And Disadvantages Of Variable Rate Irrigation – An Updated Review, S. A. O’Shaughnessy, Steve R. Evett, Paul D. Colaizzi, Manuel A. Andrade, Thomas H. Marek, Derek M. Heeren, Freddie R. Lamm, Jacob L. Larue Jan 2019

Identifying Advantages And Disadvantages Of Variable Rate Irrigation – An Updated Review, S. A. O’Shaughnessy, Steve R. Evett, Paul D. Colaizzi, Manuel A. Andrade, Thomas H. Marek, Derek M. Heeren, Freddie R. Lamm, Jacob L. Larue

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Variable rate irrigation (VRI) sprinklers on mechanical move irrigation systems (center pivot or lateral move) have been commercially available since 2004. Although the number of VRI, zone or individual sprinkler, systems adopted to date is lower than expected there is a continued interest to harness this technology, especially when climate variability, regulatory nutrient management, water conservation policies, and declining water for agriculture compound the challenges involved for irrigated crop production. This article reviews the potential advantages and potential disadvantages of VRI technology for moving sprinklers, provides updated examples on such aspects, suggests a protocol for designing and implementing VRI technology …


Modeled And Measured Ecosystem Respiration In Maize–Soybean Systems Over 10 Years, Ming Zhan, Adam Liska, Anthony Nguy-Robertson, Andrew E. Suyker, Matthew P. Pelton, Haishun Yang Jan 2019

Modeled And Measured Ecosystem Respiration In Maize–Soybean Systems Over 10 Years, Ming Zhan, Adam Liska, Anthony Nguy-Robertson, Andrew E. Suyker, Matthew P. Pelton, Haishun Yang

Adam Liska Papers

Crop residue is an abundant resource for the potential production of biofuels, but a better understanding of its use on net carbon emissions must be developed to mitigate climate change. This analysis combines two established crop growth models (Hybrid-Maize and SoySim) with a simple soil and crop residue respiration model to estimate daily ecosystem respiration (ERe) from maize and soybean; ERe was estimated to be the sum of CO2 emissions from the oxidation of the growing crop, crop residue, and soil organic carbon (SOC). Model-estimated CO2 fluxes from irrigated continuous maize and irrigated maize–soybean cropping systems in eastern …


Investigation Of Electrolytic Flocculation For Microalga Scenedesmus Sp Using Aluminum And Graphite Electrodes, Shihong Liu, Husam A. Abu Hajar, Guy Riefler, Ben J. Stuart Dec 2018

Investigation Of Electrolytic Flocculation For Microalga Scenedesmus Sp Using Aluminum And Graphite Electrodes, Shihong Liu, Husam A. Abu Hajar, Guy Riefler, Ben J. Stuart

Civil & Environmental Engineering Faculty Publications

Electrolytic flocculation using non-sacrificial electrodes with flocculants added was studied on harvesting Scenedesmus sp. In order to optimize the operating conditions of the electrolytic flocculation process and to quantify the amount of flocculants added, aluminum electrodes were first used in the process. It was found that under optimal conditions, the microalgae removal efficiency using aluminum electrodes could reach 98.5%, while 34.2 mg L-1 of aluminum ions were released during the process. Different metal electrodes were also studied, but high microalgae removal efficiency was witnessed only using aluminum electrodes, indicating the influence of the aluminum ion in flocculation. When non-sacrificial …


Water, Energy, And Carbon Footprints Of Bioethanol From The U.S. And Brazil, Mesfin Mekonnen, Thiago L. Romanelli, Chittaranjan Ray, Arjen Y. Hoekstra, Adam Liska, Christopher M. U. Neale Nov 2018

Water, Energy, And Carbon Footprints Of Bioethanol From The U.S. And Brazil, Mesfin Mekonnen, Thiago L. Romanelli, Chittaranjan Ray, Arjen Y. Hoekstra, Adam Liska, Christopher M. U. Neale

Adam Liska Papers

Driven by biofuel policies, which aim to reduce greenhouse gas (GHG) emissions and increase domestic energy supply, global production and consumption of bioethanol have doubled between 2007 and 2016, with rapid growth in corn-based bioethanol in the U.S. and sugar cane-based bioethanol in Brazil. Advances in crop yields, energy use efficiency in fertilizer production, biomass-to-ethanol conversion rates, and energy efficiency in ethanol production have improved the energy balance and GHG emission reduction potential of bioethanol. In the current study, the water, energy, and carbon footprints of bioethanol from corn in the U.S. and sugar cane in Brazil were assessed. The …


Fractionation And Characterization Of Lignin Streams From Unique High-Lignin Content Endocarp Feedstocks, Wenqi Li, Kirtley Amos, Mi Li, Yunqiao Pu, Seth Debolt, Arthur J. Ragauskas, Jian Shi Nov 2018

Fractionation And Characterization Of Lignin Streams From Unique High-Lignin Content Endocarp Feedstocks, Wenqi Li, Kirtley Amos, Mi Li, Yunqiao Pu, Seth Debolt, Arthur J. Ragauskas, Jian Shi

Biosystems and Agricultural Engineering Faculty Publications

Background: Lignin is a promising source of building blocks for upgrading to valuable aromatic chemicals and materials. Endocarp biomass represents a non-edible crop residue in an existing agricultural setting which cannot be used as animal feed nor soil amendment. With significantly higher lignin content and bulk energy density, endo-carps have significant advantages to be converted into both biofuel and bioproducts as compared to other biomass resources. Deep eutectic solvent (DES) is highly effective in fractionating lignin from a variety of biomass feedstocks with high yield and purity while at lower cost comparing to certain ionic liquids.

Results: In the present …


Catalytic Deoxygenation Of Model And Realistic Feeds To Fuel-Like Hydrocarbons Over Supported Nickel-Copper Catalysts, Deyshon Ward, Kazi Javed Nov 2018

Catalytic Deoxygenation Of Model And Realistic Feeds To Fuel-Like Hydrocarbons Over Supported Nickel-Copper Catalysts, Deyshon Ward, Kazi Javed

Posters-at-the-Capitol

The goal was to make a renewable fuel by using catalysts to remove oxygen molecules from fats. This is a current issue that society faces today because nonrenewable fossil fuels hurt the environment more than they help it. There are two components that make up a heterogeneous catalyst, a support and a reduced metal active phase. The active metal phases Nickel, Palladium, Platinum have been studied in the past on an alumina and carbon supports. We were investigating other supports using Nickel as the active phase component to determine the effect the support has on the catalyst removing oxygen of …


Assessing The Relationship Between Groundwater Nitrate Concentrations And Environmental Variables Through Repeat Sampling And Statistical Machine Learning: Dutch Flats, Nebraska, Martin Wells Sep 2018

Assessing The Relationship Between Groundwater Nitrate Concentrations And Environmental Variables Through Repeat Sampling And Statistical Machine Learning: Dutch Flats, Nebraska, Martin Wells

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Nitrate-contaminated aquifers are common in landscapes dominated by agricultural land use. Health concerns related to consuming nitrate-contaminated groundwater are well documented and continued research aimed at decreasing concentrations is critical. A 1990s U.S. Geological Survey (USGS) study focused on groundwater characteristics in the Dutch Flats area of western Nebraska. Agricultural-related practices were determined to largely influence groundwater recharge and nitrate concentrations ([NO3-]). Since the conclusion of the USGS study, a transition to more efficient irrigation technology has been observed in this region. The emphasis of this 2016 study was to resample several well nests examined in 1998 …


Cover Crops Have Negligible Impact On Soil Water In Nebraska Maize–Soybean Rotation, J. Burdette Barker, Derek M. Heeren, Katja Koehler-Cole, Charles Shapiro, Humberto Blanco-Canqui, Roger W. Elmore, Christopher A. Proctor, Suat Irmak, Charles A. Francis, Tim M. Shaver, Ali T. Mohammed Aug 2018

Cover Crops Have Negligible Impact On Soil Water In Nebraska Maize–Soybean Rotation, J. Burdette Barker, Derek M. Heeren, Katja Koehler-Cole, Charles Shapiro, Humberto Blanco-Canqui, Roger W. Elmore, Christopher A. Proctor, Suat Irmak, Charles A. Francis, Tim M. Shaver, Ali T. Mohammed

Department of Agricultural and Biological Systems Engineering: Faculty Publications

One perceived cost of integrating winter cover cropping in maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotation systems is the potential negative impact on soil water storage available for primary crop production. The objective of this 3-year study was to evaluate the effects of winter cover crops on soil water storage and cover crop biomass production following no-till maize and soybean rotations. Locations were near Brule (west-central), Clay Center (south-central), Concord (northeast), and Mead (east-central), Nebraska, United States. Treatments included crop residue only (no cover crop) and a multi-species cover crop mix, both broadcast-seeded before …


Adam J. Liska: Curriculum Vitae, Adam Liska May 2018

Adam J. Liska: Curriculum Vitae, Adam Liska

Adam Liska Papers

Associate Professor, George Dempster Smith Chair of Industrial Ecology, Departments of Biological Systems Engineering and Agronomy & Horticulture, University of Nebraska-Lincoln 236 L.W. Chase Hall, Lincoln, NE 68583-0726, Ph: (402) 472-8744, e-mail: [email protected]

Ph.D. 2003 Biology (magna cum laude), Max Planck Institute of Molecular Cell Biology & Genetics, Technische Universität Dresden, Dresden, Germany


Investigating Initial Interactions Between Silver Nanoparticles And Wastewater, Casey Gibson May 2018

Investigating Initial Interactions Between Silver Nanoparticles And Wastewater, Casey Gibson

Biological and Agricultural Engineering Undergraduate Honors Theses

The use of nanoparticles (NPs) has increased exponentially in the last 15-20 years, especially in the consumer market. NPs are currently found in over 1800 commercial products, including cosmetics, clothing, packaging, and toys. As a result, NPs can enter the environment via wastewater (WW) streams, leading to new challenges in WW treatment. This study focuses on the initial fate of silver nanoparticles (AgNPs) in WW. The AgNP interaction including aggregation and dissolution in both synthetic and real WW were studied. Real WW was collected from the primary-clarifier, secondary-clarifier, and effluent WW streams at two local WW treatment plants (Westside and …


Performance Assessment Of Solid State Anaerobic Digestion Of Poultry Litter, Mason Puckett May 2018

Performance Assessment Of Solid State Anaerobic Digestion Of Poultry Litter, Mason Puckett

Biological and Agricultural Engineering Undergraduate Honors Theses

The disposal of poultry litter can exert an economic and environmental burden to the agriculture community. As a result, it is desirable to reduce the amount of waste and recover resources from the waste. This study focuses on the construction and preliminary testing of a laboratory scale (20 L) solid state anaerobic digester (AD) fed with dry poultry litter. Glucose was added in addition to the poultry litter to achieve the appropriate C:N ratio to support the growth of anaerobic microorganisms. The AD was first fed every 4 days at 4 g VS/L/feeding for 24 days, rested (no feeding) for …


Evaluation Of A Hybrid Reflectance-Based Crop Coefficient And Energy Balance Evapotranspiration Model For Irrigation Management, J. Burdette Barker, Christopher M. U. Neale, Derek M. Heeren, Andrew E. Suyker Apr 2018

Evaluation Of A Hybrid Reflectance-Based Crop Coefficient And Energy Balance Evapotranspiration Model For Irrigation Management, J. Burdette Barker, Christopher M. U. Neale, Derek M. Heeren, Andrew E. Suyker

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Accurate generation of spatial soil water maps is useful for many types of irrigation management. A hybrid remote sensing evapotranspiration (ET) model combining reflectance-based basal crop coefficients (Kcbrf) and a two-source energy balance (TSEB) model was modified and validated for use in real-time irrigation management. We modeled spatial ET for maize and soybean fields in eastern Nebraska for the 2011-2013 growing seasons. We used Landsat 5, 7, and 8 imagery as remote sensing inputs. In the TSEB, we used the Priestly-Taylor (PT) approximation for canopy latent heat flux, as in the original model formulations. We also used the …


Climate-Driven Crop Yield And Yield Variability And Climate Change Impacts On The U.S. Great Plains Agricultural Production, Meetpal Singh Kukal, Suat Irmak Feb 2018

Climate-Driven Crop Yield And Yield Variability And Climate Change Impacts On The U.S. Great Plains Agricultural Production, Meetpal Singh Kukal, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Climate variability and trends affect global crop yields and are characterized as highly dependent on location, crop type, and irrigation. U.S. Great Plains, due to its significance in national food production, evident climate variability, and extensive irrigation is an ideal region of investigation for climate impacts on food production. This paper evaluates climate impacts on maize, sorghum, and soybean yields and effect of irrigation for individual counties in this region by employing extensive crop yield and climate datasets from 1968–2013. Variability in crop yields was a quarter of the regional average yields, with a quarter of this variability explained by …


Assessing Intra-Event Phosphorus Dynamics In Drainage Water Using Phosphate Stable Oxygen Isotopes, William Ford Iii, Mark R. Williams, Megan B. Young, Kevin W. King, Eric Fischer Jan 2018

Assessing Intra-Event Phosphorus Dynamics In Drainage Water Using Phosphate Stable Oxygen Isotopes, William Ford Iii, Mark R. Williams, Megan B. Young, Kevin W. King, Eric Fischer

Biosystems and Agricultural Engineering Faculty Publications

Quantifying fluxes and pathways of dissolved reactive phosphorus (DRP) in tile-drained landscapes has been hampered by a lack of measurements that are sensitive to P fate and transport processes. One potential tool to help understand these dynamics is the oxygen isotope signature of phosphate (δ18OPO4); however, its potential benefits and limitations are not well understood for intra-event dynamics at the field scale. The objectives of this study were to quantify intra-event variability of δ18OPO4 signatures in tile drainage water and assess the efficacy of δ18OPO4 to elucidate mechanisms and flow …


Processing Different Mixtures Of Regionally Available Resources To Create Pellets That Meet A Minimum Standard, Jacob Hixson Jan 2018

Processing Different Mixtures Of Regionally Available Resources To Create Pellets That Meet A Minimum Standard, Jacob Hixson

Masters Theses

There are several ways to produce energy today, one of the oldest is the gasification of biomass. This process uses a fire to heat the material until it starts to produce gasses that are used as fuel. There are several types of biomass that can be used, many of which have large pieces with low bulk densities. By pelletizing the biomass bulk density increases and allows the opportunity to add in other biomass materials.

There are standards for condensing large pieces of biomass to smaller pelletized materials. Pellet Fuels Institute has set minimum standards for pellets used in the different …


Application Of Drainage Water Management And Saturated Buffers For Conservation Drainage In South Dakota, Abhinav Sharma Jan 2018

Application Of Drainage Water Management And Saturated Buffers For Conservation Drainage In South Dakota, Abhinav Sharma

Electronic Theses and Dissertations

Edge of field practices such as drainage water management (DWM) and saturated buffers can reduce nutrient transport from croplands to surface waterbodies. DWM uses stackable weir boards in a control structure to manipulate the water table depth throughout the cropping season and reduce the amount of nutrient rich water draining out from the field. Saturated buffers, on the other hand, use a control structure to divert water draining out from the cropland to a vegetative strip via a subsurface tile installed parallel to a waterway. For the saturated buffer systems, a combination of natural denitrification, nitrogen mineralization, and plant uptake …


2018 Nebraska Groundwater Quality Monitoring Report Jan 2018

2018 Nebraska Groundwater Quality Monitoring Report

Nebraska Department of Environmental Quality: Reports

The 2001 Nebraska Legislature passed LB329 (Neb. Rev. Stat. §46-1304) which, in part, directed the Nebraska Department of Environmental Quality (NDEQ) to report on groundwater quality monitoring in Nebraska. Reports have been issued annually since December 2001. The text of the statute applicable to this report follows: “The Department of Environmental Quality shall prepare a report outlining the extent of ground water quality monitoring conducted by natural resources districts during the preceding calendar year. The department shall analyze the data collected for the purpose of determining whether or not ground water quality is degrading or improving and shall present the …


Application Of Acoustic Emission And Machine Learning To Detect Codling Moth Infested Apples, Mengxing Li, Nader Ekramirad, Ahmed Rady, Akinbode A. Adedeji Jan 2018

Application Of Acoustic Emission And Machine Learning To Detect Codling Moth Infested Apples, Mengxing Li, Nader Ekramirad, Ahmed Rady, Akinbode A. Adedeji

Biosystems and Agricultural Engineering Faculty Publications

Incidence of codling moth (CM) (Cydia pomonella L.) infestation in apples has been a major concern in North America for decades. CM larvae bore deep into the fruit, making it unmarketable. An effective noninvasive method to detect larvae-infested apples is necessary to ensure that apples are CM-free in post-harvest processing. In this study, a novel approach using an acoustic emission (AE) system and subsequent machine learning methods was applied to classify larvae-infested apples from intact apples. 'GoldRush‘ apples were infested with CM neonates and stored at the same conditions as intact apples. The AE system was used to collect …


Improving In-Stream Nutrient Routines In Water Quality Models Using Stable Isotope Tracers: A Review And Synthesis, Alexandria K. Jensen, William I. Ford, James F. Fox, Admin Husic Jan 2018

Improving In-Stream Nutrient Routines In Water Quality Models Using Stable Isotope Tracers: A Review And Synthesis, Alexandria K. Jensen, William I. Ford, James F. Fox, Admin Husic

Biosystems and Agricultural Engineering Faculty Publications

Water quality models serve as an economically feasible alternative to quantify fluxes of nutrient pollution and to simulate effective mitigation strategies; however, their applicability is often questioned due to broad uncertainties in model structure and parameterization, leading to uncertain outputs. We argue that reduction of uncertainty is partially achieved by integrating stable isotope data streams within the water quality model architecture. This article outlines the use of stable isotopes as a response variable within water quality models to improve the model boundary conditions associated with nutrient source provenance, constrain model parameterization, and elucidate shortcomings in the model structure. To assist …


A Multi-Criteria And Dynamic Sustainability Assessment Of Crop Rotation Alternatives, Saturnina Fabian Nisperos Jan 2018

A Multi-Criteria And Dynamic Sustainability Assessment Of Crop Rotation Alternatives, Saturnina Fabian Nisperos

Computational Modeling & Simulation Engineering Theses & Dissertations

With the food security challenge faced by nations globally, agriculture sustainability has been a significant consideration for concerned agencies. Sustainability assessments are significant tools in providing support to stakeholders in their crop production planning. Agricultural sustainability assessment, however, is complex and it involves numerous criteria that can be conflicting. Limitations on crop rotation sustainability assessment methods include: non-dynamic assessment; lack of regard to cover crops and to the individual crop production preferences of farmers; and focused only on single-year and single-crop rotation. We sought to address these limitations by developing a multi-criteria and dynamic sustainability assessment model that considers the …


Evaluating E. Coli Particle Attachment And The Impact On Transport During High Flows, Louis Amegbletor Jan 2018

Evaluating E. Coli Particle Attachment And The Impact On Transport During High Flows, Louis Amegbletor

Electronic Theses and Dissertations

Fecal indicator bacteria, including E. coli, are the leading cause of water quality impairments within assessed waters in the United States. The source of E. coli includes WWTP, leaking sewers, animal manure, wildlife, livestock, and stream bed sediment. Storm events contribute to bacteria loading within waters through wash-in of land sources of bacteria and resuspension of bacteria within sediments. Bacteria introduced into the water column are either attached to particles or are unattached (or free-living). The goal of this study was to examine the attachment of E. coli to different particle sizes, including their impact on contributing to water …


Three-Dimensional Modeling Of Nitrate-N Transport In Vadose Zone: Roles Of Soil Heterogeneity And Groundwater Flux, Simin Akbariyeh, Shannon L. Bartelt-Hunt, Daniel D. Snow, Xu Li, Zhenghong Tang, Yusong Li Jan 2018

Three-Dimensional Modeling Of Nitrate-N Transport In Vadose Zone: Roles Of Soil Heterogeneity And Groundwater Flux, Simin Akbariyeh, Shannon L. Bartelt-Hunt, Daniel D. Snow, Xu Li, Zhenghong Tang, Yusong Li

Department of Civil and Environmental Engineering: Faculty Publications

Contamination of groundwater from nitrogen fertilizers in agricultural lands is an important environmental and water quality management issue. It is well recognized that in agriculturally intensive areas, fertilizers and pesticides may leach through the vadose zone and eventually reach groundwater. While numerical models are commonly used to simulate fate and transport of agricultural contaminants, few models have considered a controlled field work to investigate the influence of soil heterogeneity and groundwater flow on nitrate-N distribution in both root zone and deep vadose zone.

In this work, a numerical model was developed to simulate nitrate-N transport and transformation beneath a center …


A Risk-Based Method For Estimating The Carbon Sequestration Budget For A Mixed Hardwood Forest, Erin Cooper Dec 2017

A Risk-Based Method For Estimating The Carbon Sequestration Budget For A Mixed Hardwood Forest, Erin Cooper

Chemical Engineering Undergraduate Honors Theses

Carbon Dioxide (CO2) levels in the atmosphere have risen from approximately 310 ppm in the 1950’s to over 400 ppm as of 2015. This rise in CO2 has likely resulted in the observed warming trend of the earth’s atmosphere in the same time frame, causing significant concern in the scientific community. Several mitigation strategies have arisen to combat the upward trend of CO2 emissions in recent decades, among them being carbon sequestration- the process of capturing CO2 from the atmosphere and holding it for an extended period of time. This study used the U.S. Forest …