Engineering Commons^™

In Vivo Evaluation Of Oxygenic Photogranules’ Photosynthetic Capacity By Pulse Amplitude Modulation And Phototrophic–Irradiance Curves, Joseph G. Gikonyo, Andrew Keyser, John Tobiason, Jeeyon Jeong, Chul Park

Civil and Environmental Engineering Faculty Publication Series

The commingled microbial moiety of oxygenic photogranules (OPGs) facilitates aeration-free wastewater treatment. Embedded in an extracellular polymeric substances (EPS) matrix, microbial producers and consumers of oxygen occupying granular niches exchange substrates among themselves and with the bulk fluid. An assessment of the OPG's phototrophic potential or functional capacity may require combining different photoactivity signals. The photosynthetic capacity was evaluated using photosynthetic oxygen evolution (POE) and chlorophyll fluorescence (rapid light curves, RLC) measurements using OPGs grown at different light intensities.. A maximum oxygen generating capacity for optimal OPGs and reactor conditions was determined to be 284.4 mgO(2) gVSS(-1) h(-1) The OPGs …

Momentum Towards Incorporating Global Responsibility In Engineering Education And Accreditation In The Uk, Jonathan Truslove, Emma Crichton, Shannon Chance, Katie Cresswell-Maynard

Conference papers

CONTEXT Engineering is uniquely placed to help address global challenges such as those surrounding the climate crisis, and the sustainable use and management of resources. However, studies have found UK engineering companies that have adopted sustainability strategies do not have enough staff with the skills to achieve them. There is an urgent need to upskill the current workforce and prepare future generations to operate in a responsible and ethical manner in tackling today's challenges. Recent updates to the standard of engineering accreditation in the UK provide notable opportunities to transform university curricula to create globally responsible engineers.

PURPOSE This preliminary …

High-Temperature Performance Of Ambient-Cured Alkali- Activated Binder Concrete, Kruthi Kiran Ramagiri, Darshan Chauhan, Shashank Gupta, Arkamitra Kar, Dibyendu Adak, Abhijit Mukherjee

Civil and Environmental Engineering Faculty Publications and Presentations

Owing to their lower carbon footprint and efficient performance compared to portland cement (PC), alkali-activated binders (AAB) show promising potential as an alternative to PC. The present paper investigates the high-temperature performance of AAB concrete through compressive and bond strength tests. Four different AAB concrete mixes with varying proportions of fly ash: slag (100:0, 70:30, 60:40, and 50:50) cured under ambient conditions are exposed to elevated temperatures. The mechanical performance of AAB concrete is corroborated with microstructural changes. The results show that AAB concrete with fly ash: slag ratio of 70:30 exhibits the best mechanical performance after exposure to elevated …

Combining Electrochemical Nitrate Reduction And Anammox For Treatment Of Nitrate-Rich Wastewater: A Short Review, Xinyi Zou, Chongjun Chen, Changhong Wang, Qun Zhang, Zhuowei Yu, Haiping Wu, Chao Zhuo, Tian C. Zhang

Department of Civil and Environmental Engineering: Faculty Publications

Treatment of nitrate-rich wastewater is important but challenging for the conventional biological denitrification process. Here, we propose combining the electrochemical reduction and anaerobic ammonium oxidation (anammox) processes together for treatment of nitrate-rich wastewater. This article reviews the mechanism and current research status of electrochemical reduction of nitrate to ammonium as well as the mechanism and applicability of the anammox process. This article discusses the principles, superiorities, and challenges of this combined process. The feasibility of the combined process depends on the efficiency of electrochemical nitrate reduction to ammonium and the conditions in the anammox process to use the reduced ammonium …

Nebraska Water Center Annual Report 2019-2020

Literature from The Nebraska Water Center

Contents

Introduction: Foreword • Director’s Letter • Nebraska Water Center (NWC) Overview and Timeline • In Memoriam: Kyle Hoagland

Research • Water Sciences Laboratory • Nebraska Vadose Zone Program • Ogallala Water Coordinated Agriculture Project • Water for Agriculture Project • Greeley Award • U.S. Geological Survey 104b Projects

Extension & Outreach: NWC Events • Nebraska Nitrate Initiative • Bazile Groundwater Management Area • Water and Integrated Crops Hub • Water Faculty Directory • State Legislative Funding • Water Resources Advisory Panel

Teaching: Know Your Well • Sorab Panday Spotlight • NWC Postdoc Profiles • NWC Student Intern Profiles • …

Moffatt Eddies In Subglacial Mountain Valleys, Emily Martinez

ENGS 88 Honors Thesis (AB Students)

Currently, there is a global emphasis in finding the oldest ice in Antarctica, which will give the longest climate record contained within the ice. This is fundamental in the field of climate science because it will give scientists a proper baseline to compare it to sediment cores amongst other proxy records and work to determine a more accurate account of climate change. The most promising place to find the oldest ice is within the thick, slow-moving East Antarctic Ice Sheet. Within this ice sheet, there is a thick region of ice that sits on a mountain range known as the …

Laboratory Study Of The Effects Of Flexible Vegetation On Solute Diffusion In Unidirectional Flow, Sha Lou, Hao Wang, Hongzhe Liu, Guihui Zhong, Larisa Dorzhievna Radnaeva, Elena Nikitina, Gangfeng Ma, Shuguang Liu

Civil & Environmental Engineering Faculty Publications

Background

Flexible vegetation is an important part of the riverine ecosystem, which can reduce flow velocity, change turbulence structure, and affect the processes of solute transport. Compared with the flow with rigid vegetation, which has been reported in many previous studies, bending of flexible vegetation increases the complexity of the flow-vegetation-solute interactions. In this study, laboratory experiments are carried out to investigate the influence of flexible vegetation on solute transport, and methods for estimating the lateral and longitudinal diffusion coefficients in the rigid vegetated flow are examined for their applications to the flow with flexible vegetation.

Results

The experimental observations …

Water Quality Engineering And Wastewater Treatment, Yung-Tse Hung, Hamidi Abdul Aziz, Issam A. Al-Khatib, Rehab O. Abdel Rahman, Mario Gr Cora-Hernandez

Civil and Environmental Engineering Faculty Publications

No abstract provided.

Characterizing Seagrass Effects On Hydrodynamics Of Waves And Currents Through Field Measurements And Computational Modelling, Ramin Familkhalili, Navid Tahvildari

Civil & Environmental Engineering Faculty Publications

Low-lying coastal and estuarine areas are among the most populated regions globally, have high economic significance, and are increasingly threatened by climate change, sea level rise, nuisance flooding, and extreme storms. Nature-based coastal protections are sustainable and sea-level resilient alternatives compared to traditional solutions such as dikes and seawalls. Submerged aquatic vegetation (SAV) or seagrasses can provide coastal flood and erosion protection by attenuating storm wave and current energy and stabilizing seabed sediments. However, more research is needed to understand the interactions between flow, SAVs, and sediments. These dynamic interactions affect flow at different scales and seagrass productivity. In this …

The Influence Of Channel Deepening On Tides, River Discharge Effects, And Storm Surge, S. A. Talke, Ramin Familkhalili, D. A. Jay

Civil & Environmental Engineering Faculty Publications

We combine archival research, semi-analytical models, and numerical simulations to address the following question: how do changes to channel geometry alter tidal properties and flood dynamics in a hyposynchronous, strongly frictional estuary with a landward decay in tidal amplitudes? Records in the Saint Johns River Estuary since the 1890s show that tidal range has doubled in Jacksonville, Florida. Near the estuary inlet, tidal discharge approximately doubled but tidal amplitudes increased only ∼6%. Modeling shows that increased shipping channel depths from ∼5 to ∼13m drove the observed changes, with other factors like channel shortening and width reduction producing comparatively minor effects. …

Large-Scale Variation In Wave Attenuation Of Oyster Reef Living Shorelines And The Influence Of Inundation Duration, Rebecca L. Morris, Megan K. La Peyre, Bret M. Webb, Danielle A. Marshall, Donna M. Bilkovic, Just Cebrian, Giovanna Mcclenachan, Kelly M. Kibler, Linda J. Walters, David Bushek, Eric L. Sparks, Nigel A. Temple, Joshua Moody, Kory Angstadt, Joshua Goff, Maura Boswell, Paul Sacks, Stephen E. Swearer

Civil & Environmental Engineering Faculty Publications

One of the paramount goals of oyster reef living shorelines is to achieve sustained and adaptive coastal protection, which requires meeting ecological (i.e., develop a self-sustaining oyster population) and engineering (i.e., provide coastal defense) targets. In a large-scale comparison along the Atlantic and Gulf coasts of the United States, the efficacy of various designs of oyster reef living shorelines at providing wave attenuation was evaluated accounting for the ecological limitations of oysters with regards to inundation duration. A critical threshold for intertidal oyster reef establishment is 50% inundation duration. Living shorelines that spent less than half of the time ( …

Optimisation Of Retrofit Wall Insulation: An Irish Case Study, Rakshit D. Muddu, D M. Gowda, Anthony James Robinson, Aimee Byrne

Articles

Ireland has one of the highest rates of emissions per capita in the world and its residential sector is responsible for approximately 10% of total national CO2 emissions. Therefore, reducing the CO2 emissions in this sector will play a decisive role in achieving EU targets of reducing emissions by 40% by 2030. To better inform decisions regarding retrofit of the existing building stock, this study proposes Optimum Insulation Thicknesses (OIT) for typical walls in 25 regions in Ireland. The calculation of OIT includes annual heat energy expenditure, CO2 emissions, and material payback period. The approach taken is based on Heating …

Quantification Of Nitric Oxide Concentration Using Single-Walled Carbon Nanotube Sensors, Jakob Meier, Joseph Stapleton, Eric M. Hofferber, Abigail Haworth, Stephen D. Kachman, Nicole M. Iverson

Department of Biological Systems Engineering: Papers and Publications

Nitric oxide (NO), a free radical present in biological systems, can have many detrimental effects on the body, from inflammation to cancer. Due to NO’s short half-life, detection and quan- tification is difficult. The inability to quantify NO has hindered researchers’ understanding of its impact in healthy and diseased conditions. Single-walled carbon nanotubes (SWNTs), when wrapped in a specific single-stranded DNA chain, becomes selective to NO, creating a fluorescence sensor. Unfortunately, the correlation between NO concentration and the SWNT’s fluorescence intensity has been difficult to determine due to an inability to immobilize the sensor without altering its properties. Through the …

Modeling And Prioritizing Interventions Using Pollution Hotspots For Reducing Nutrients, Atrazine And E. Coli Concentrations In A Watershed, Olufemi P. Abimbola, Aaron R. Mittelstet, Tiffany Messer, Elaine Berry, Anna Van Griensven

Department of Biological Systems Engineering: Papers and Publications

Excess nutrients and herbicides remain two major causes of waterbody impairment globally. In an attempt to better understand pollutant sources in the Big Sandy Creek Watershed (BSCW) and the prospects for successful remediation, a program was initiated to assist agricultural producers with the implementation of best management practices (BMPs). The objectives were to (1) simulate BMPs within hotspots to determine reductions in pollutant loads and (2) to determine if water-quality standards are met at the watershed outlet. Regression-based load estimator (LOADEST) was used for determining sediment, nutrient and atrazine loads, while artificial neural networks (ANN) were used for determining E. …

Assessing Different Plant-Centric Water Stress Metrics For Irrigation Efficacy Using Soil-Plant-Atmosphere-Continuum Simulation, Jingwen Zhang, Kaiyu Guan, Bin Peng, Ming Pan, Wang Zhou, Robert F. Grant, Trenton E. Franz, Daran Rudnick, Derek M. Heeren, Andrew Suyker, Yi Yang, Genghong Wu

Department of Biological Systems Engineering: Papers and Publications

Understanding plant water stress (PWS) in the soil-plant-atmosphere-continuum (SPAC) that connects water supply from soil, water demand from atmosphere, and plant self-regulation is a prerequisite for efficient irrigation in response to water scarcity. Currently, PWS can be defined in various ways, for example, based on environmental factors and/or plant-centric metrics. The environment-based metrics usually do not take plants into consideration. Regarding the existing plant-centric metrics, their interconnections and abilities to capture the physical water constraints from both soil water supply and atmospheric water demand are still unclear. This research investigates the theoretical foundations behind different PWS metrics, and assesses their …

Antibiotic Resistance Genes In Swine Manure Slurry As Affected By Pit Additives And Facility Disinfectants, Maria C. Hall, Jon Duerschner, John E. Gilley, Amy Schmidt, Shannon Bartelt-Hunt, Daniel D. Snow, Kent M. Eskridge, Xu Li

Department of Biological Systems Engineering: Papers and Publications

Manure storage facilities are critical control points to reduce antibiotic resistance genes (ARGs) in swine manure slurry before the slurry is land applied. However, little is known about how exogenous chemicals entering the manure storage facilities may affect the fate of ARGs. The objective of this study was to analyze the impact of six commonly used pit additives and four facility disinfectants on the concentration of ARGs in swine manure slurry. Bench scale reactors, each containing approximately 50 L of liquid swine manure, were dosed with additives or disinfectants and were sampled for 40 days. Seven antibiotic resistance genes along …

Differential Survival Of Non-O157 Shiga Toxigenic Escherichia Coli In Simulated Cattle Feedlot Runoff, Lisa M. Durso, John E. Gilley, Daniel N. Miller

Department of Biological Systems Engineering: Papers and Publications

Environmental survival time is important when evaluating adverse health outcomes from foodborne pathogens. Although outbreaks associated with manure-impacted irrigation or runoff water are relatively infrequent, their broad scope, regulatory importance, and severe health outcomes highlight the need to better understand the environmental survival of manure-borne pathogens. Shiga toxigenic Escherichia coli (STEC) are excreted in feces and persist in the environment until they die or recolonize a new host. Surface waters contaminated with manure-borne STEC can infect humans through drinking and recreational water use or irrigated crops that are minimally cooked. In this study, manure-impacted water microcosms mimicking beef cattle feedlot …

Editorial: Predictive Modeling Of Human Microbiota And Their Role In Health And Disease, Hyun-Seob Song, Stephen R. Lindemann, Dong-Yup Lee

Department of Biological Systems Engineering: Papers and Publications

No abstract provided.

Low-Level Groundwater Atrazine In High Atrazine Usage Nebraska Counties: Likely Effects Of Excessive Groundwater Abstraction, Moses New-Aaron, Olufemi Abimbola, Raheleh Mohammadi, Oluwaseun Famojuro, Zaeema Naveed, Azar Abadi, Jesse E. Bell, Shannon Bartelt-Hunt, Eleanor G. Rogan

Department of Biological Systems Engineering: Papers and Publications

Recent studies observed a correlation between estrogen-related cancers and groundwater atrazine in eastern Nebraska counties. However, the mechanisms of human exposure to atrazine are unclear because low groundwater atrazine concentration was observed in counties with high cancer incidence despite having the highest atrazine usage. We studied groundwater atrazine fate in high atrazine usage Nebraska counties. Data were collected from Quality Assessed Agrichemical Contaminant Nebraska Groundwater, Parameter–Elevation Regressions on Independent Slopes Model (PRISM), and water use databases. Descriptive statistics and cluster analysis were performed. Domestic wells (59%) were the predominant well type. Groundwater atrazine was affected by well depth. Clusters consisting …

Improvements In Sub-Catchment Fractional Snowpack And Snowmelt Parameterizations And Hydrologic Modeling For Climate Change Assessments In The Western Himalayas, Vishal Singh, Francisco Muñoz-Arriola

Department of Biological Systems Engineering: Papers and Publications

The present work proposes to improve estimates of snowpack and snowmelt and their assessment in the steep Himalayan ranges at the sub-catchment scale. Temporal variability of streamflow and the associated distribution of accumulated snow in catchments with glacier presence in the Himalayas illustrates how changes in snowpack and snowmelt can affect the water supply for local water management. The primary objective of this study is to assess the role of elevation, temperature lapse rate (TLR), and precipitation lapse rate (PLR) in the computation of snowpack (or snowfall) and snowmelt in sub-catchments of the Satluj River basin. Modeling of snowpack and …

The Nanotheranostic Researcher’S Guide For Use Of Animal Models Of Traumatic Brain Injury, Brandon Z. Mcdonald, Connor C. Gee, Forrest M. Kievit

Department of Biological Systems Engineering: Papers and Publications

Traumatic brain injury (TBI) is currently the leading cause of injury-related morbidity and mortality worldwide, with an estimated global cost of USD 400 billion annually. Both clinical and preclinical behavioral outcomes associated with TBI are heterogeneous in nature and influenced by the mechanism and frequency of injury. Previous literature has investigated this relationship through the development of animal models and behavioral tasks. However, recent advancements in these methods may provide insight into the translation of therapeutics into a clinical setting. In this review, we characterize various animal models and behavioral tasks to provide guidelines for evaluating the therapeutic efficacy of …

Evolution Of Three Streambanks Before And After Stabilization And Record Flooding, Matthew Russell, Aaron R. Mittelstet, Tiffany Messer, Jesse T. Korus, R.M. Joeckel

Department of Biological Systems Engineering: Papers and Publications

Stabilization projects are increasingly used to mitigate the effects of anthropogenic streambank erosion, yet the effectiveness of stabilization has been insufficiently measured. Sound monitoring practices inform adjustments in implementation and maintenance, which improve engineered effectiveness. Thus, the objectives of this study were to: 1) measure streambank migration from in three reaches stabilized with wooden jetties following a major flooding event, and 2) quantify deposition around the jetties between pre-flood and post-flood. Streambank deposition was measured in 2019 with a River Surveyor and Global Positioning System (GPS). Bank erosion rates in Reaches 1, 2 and 3 were 0.41, 0.96 and 0.07 …

Frontier: Discipline-Based Education Research To Advance Authentic Learning In Agricultural And Biological Engineering, Heidi A. Diefes-Dux

Department of Biological Systems Engineering: Papers and Publications

Discipline-based education research (DBER) is research activity aimed at investigating “learning and teaching in a discipline from a perspective that reflects the discipline’s priorities, worldview, knowledge, and practices” for the purpose of producing research-based evidence to improve education in that discipline. DBER arose out of concerns about the quality of post-secondary science education. Physics, chemistry, engineering, biology, geosciences, and astronomy education each have unique DBER histories in the U.S. that date back to the late 1800s or early 1900s when colleges and university systems were expanding and formalizing. The DBER fields accelerated in the 1950s and 1960s as a result …

Chlorination As Drinking Water Disinfection Technique And Disinfection By Products: A Scientometric Analysis, Sapna Ramchandra Shinde, Sayali D. Apte Dr, Kanchan C. Khare Dr, Philipp Otter Mr

Library Philosophy and Practice (e-journal)

The Sustainable Development Goals (SDG) 2015, defined to achieve a better and more sustainable future, contains goal number 6 related to safe and affordable drinking water facility for all till 2030. The rural and remote areas in the developing countries predominantly face the scarcity of pathogen free drinking water leading to water borne diseases and deaths due to consumption of contaminated water indicating a need of advancement in the drinking water disinfection techniques. The paper discusses scientometric analysis of publication trends in chlorination as a popular disinfection techniques and research related to the Disinfection By Products (DBPs) that are produced …

Assessment Of Cu(In, Ga)Se₂ Solar Cells Degradation Due To Water Ingress Effect On The Cds Buffer Layer, Deewakar Poudel, Benjamin Belfore, Shankar Karki, Grace Rajan, Sina Soltanmohammad, Angus Rockett, Sylvain Marsillac

Electrical & Computer Engineering Faculty Publications

The effect of water ingress on the surface of the buffer layer of a Cu(In, Ga)Se2 (CIGS) solar cell was studied. Such degradation can occur either during the fabrication process, if it involves a chemical bath as is often the case for CdS, or while the modules are in the field and encapsulants degrade. To simulate the impact of this moisture ingress, devices with a structure sodalime glass/Mo/CIGS/CdS were immersed in deionized water. The thin films were then analyzed both pre and post water soaking. Dynamic secondary ion mass spectroscopy (SIMS) was performed on completed devices to analyze impurity diffusion …