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Articles 541 - 570 of 2277

Full-Text Articles in Civil and Environmental Engineering

Extracellular Matrix Disparities In An Nkx2-5 Mutant Mouse Model Of Congenital Heart Disease, Deanna Bousalis, Christopher S. Lacko, Nora Hlavac, Fariz Alkassis, Rebecca A. Wachs, Sahba Mobini, Christine E. Schmidt, Hideko Kasahara May 2020

Extracellular Matrix Disparities In An Nkx2-5 Mutant Mouse Model Of Congenital Heart Disease, Deanna Bousalis, Christopher S. Lacko, Nora Hlavac, Fariz Alkassis, Rebecca A. Wachs, Sahba Mobini, Christine E. Schmidt, Hideko Kasahara

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Congenital heart disease (CHD) affects almost one percent of all live births. Despite diagnostic and surgical reparative advances, the causes and mechanisms of CHD are still primarily unknown. The extracellular matrix plays a large role in cell communication, function, and differentiation, and therefore likely plays a role in disease development and pathophysiology. Cell adhesion and gap junction proteins, such as integrins and connexins, are also essential to cellular communication and behavior, and could interact directly (integrins) or indirectly (connexins) with the extracellular matrix. In this work, we explore disparities in the expression and spatial patterning of extracellular matrix, adhesion, and …


Riveted Steel Railway Bridge Health Monitoring And Damage Detection, Ahmed Rageh May 2020

Riveted Steel Railway Bridge Health Monitoring And Damage Detection, Ahmed Rageh

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Visual inspection is often used to assess the condition of railway bridges at discrete points in time, an approach that can be subjective and possibly unsafe. Alternatively, certain bridges have their condition assessed via the installation of a large number of sensors. These sensors can be costly to place, power and maintain. Therefore, reducing their numbers and maximizing the extracted information is of utmost importance. In addition, evaluating bridge condition from measured response can be quite challenging due to loading and environmental variations, especially when a limited number of sensors are used.

The focus of this research is to develop …


Evaluation Of The Dynamic Behavior Of Steel Staircases With Concrete Filled Pan Treads, Tyler Sondag May 2020

Evaluation Of The Dynamic Behavior Of Steel Staircases With Concrete Filled Pan Treads, Tyler Sondag

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Vibration serviceability of staircases has been a growing challenge for structural engineers due to changing materials and structural forms. In order to prevent or correct serviceability problems due to structural vibrations, structural engineers should be able to predict the dynamic performance of a staircase structure. However, there are few technical guides available for designing steel staircases, and the ones that do exist are often limited in their applications. Currently, there is a lack of research on staircases that are less prone to vibrations, such as staircases with concrete filled pans that are composed of face and wall stringers. Therefore, the …


Development Of An In Vitro Intervertebral Disc Innervation Model To Screen Neuroinhibitory Biomaterials, Sarah M. Romereim, Caleb A. Johnston, Adan L. Redwine,, Rebecca A. Wachs May 2020

Development Of An In Vitro Intervertebral Disc Innervation Model To Screen Neuroinhibitory Biomaterials, Sarah M. Romereim, Caleb A. Johnston, Adan L. Redwine,, Rebecca A. Wachs

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Pain originating from an intervertebral disc (discogenic pain) is a major source of chronic low back pain. Pathological innervation of the disc by pain‐sensing nerve fibers is thought to be a key component of discogenic pain, so treatment with biomaterials that have the ability to inhibit neurite growth will greatly benefit novel disc therapeutics. Currently, disc therapeutic biomaterials are rarely screened for their ability to modulate nerve growth, mainly due to a lack of models to screen neuromodulation. To address this deficit, our lab has engineered a three dimensional in vitro disc innervation model that mimics the interface between primary …


Nitrate And Herbicides Removal From Groundwater Using Immobilized Algae, Sara Mollamohammada May 2020

Nitrate And Herbicides Removal From Groundwater Using Immobilized Algae, Sara Mollamohammada

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

To improve crop yield and control broadleaf weeds, many farmers apply nitrate-based fertilizers and chemical herbicides to their fields. Excessive use of these chemicals can cause contamination in waterbodies and impact on the public health. The physical and chemical methods have been suggested to remove these herbicides are usually costly. In this study, the capability of immobilized algal beads in removing nitrate and several herbicides of environmental concern from synthetic and actual groundwater and surface water was evaluated.

The experiments were performed in batch, sequencing batch and continuous flow modes and the effect of different operational conditions (light intensity, cultivation …


Sediment Outflow Under Simulated Rainfall Conditions With Varying Geotechnical Properties, Pranjay Joshi, Akhilesh Kumar, P. V. Singh, Jahangeer Jahangeer Apr 2020

Sediment Outflow Under Simulated Rainfall Conditions With Varying Geotechnical Properties, Pranjay Joshi, Akhilesh Kumar, P. V. Singh, Jahangeer Jahangeer

Daugherty Water for Food Global Institute: Faculty Publications

The vulnerability of soil toward erosion might be reduced by having a good vegetative cover over the soil surface, slope improvement, and improving soil properties so that it is not easily detached and transported. However, the establishment of proper vegetative cover is a long process because it takes time for seeds to germinate and attain maturity. As an alternative approach, if soil resistance was increased by increasing the shear strength of soil against erosive forces offered by eroding agents, the soil system would become capable of withstanding the detachment of its particles on the application of shear stress. To achieve …


Reliability-Calibrated Ann-Based Load And Resistance Factor Load Rating For Steel Girder Bridges, Francisco Garcia Apr 2020

Reliability-Calibrated Ann-Based Load And Resistance Factor Load Rating For Steel Girder Bridges, Francisco Garcia

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This research aimed to develop a supplemental ANN-based tool to support the Nebraska Department of Transportation (NDOT) in optimizing bridge management investments when choosing between refined modeling, field testing, retrofitting, or bridge replacement. ANNs require an initial investment to collect data and train a network, but offer future benefits of speed and accessibility to engineers utilizing the trained ANN in the future. As the population of rural bridges in the Midwest approaching the end of their design service lives increases, Departments of Transportation are under mounting pressure to balance safety of the traveling public with fiscal constraints. While it is …


Evaluation Of Low-Cost Depth Cameras For Agricultural Applications, Isabella C.F.S. Condotta, Tami M. Brown-Bandl, Santosh Pitla, John P. Stinn, Késia O. Silva-Miranda Apr 2020

Evaluation Of Low-Cost Depth Cameras For Agricultural Applications, Isabella C.F.S. Condotta, Tami M. Brown-Bandl, Santosh Pitla, John P. Stinn, Késia O. Silva-Miranda

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Low-cost depth-cameras have been used in many agricultural applications with reported advantages of low cost, reliability and speed of measurement. However, some problems were also reported and seem to be technology related, so understanding the limitations of each type of depth camera technology could provide a basis for technology selection and the development of research involving its use. The cameras use one or a combination of two of the three available technologies: structured light, time-of-flight (ToF), and stereoscopy. The objectives were to evaluate these different technologies for depth sensing, including measuring accuracy and repeatability of distance data and measurements at …


The Impact Of Pev User Charging Behavior In Building Public Charging Infrastructure, Ahmad Almaghrebi Apr 2020

The Impact Of Pev User Charging Behavior In Building Public Charging Infrastructure, Ahmad Almaghrebi

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Plug-in electric vehicles (PEVs) play a significant role in the development of green cities since they generate less pollution than conventional vehicles. To promote PEV adoption and mitigate range anxiety, charging infrastructure should be deployed at strategic locations that are readily accessible to the public. Nebraska is working on the expansion of charging infrastructure around the state; however, stakeholders face several difficulties in trying to minimize irregular charging behaviors. Most electric vehicle users plug in and leave their vehicles for an extended time at public parking lots designated for PEVs. Some users even leave their vehicles for longer than 24 …


Sensitivity Analysis Of Data-Driven Groundwater Forecasts To Hydroclimatic Controls In Irrigated Croplands, Alessandro Amaranto, Francesca Pianosi, Dimitri Solomatine, Gerald Corzo-Perez, Francisco Munoz-Arriola Apr 2020

Sensitivity Analysis Of Data-Driven Groundwater Forecasts To Hydroclimatic Controls In Irrigated Croplands, Alessandro Amaranto, Francesca Pianosi, Dimitri Solomatine, Gerald Corzo-Perez, Francisco Munoz-Arriola

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In the last decades, advancements in computational science have greatly expanded the use of artificial neural networks (ANNs) in hydrogeology, including applications on groundwater forecast, variable selection, extended lead-times, and regime-specific analysis. However, ANN-model performance often omits the sensitivity to ob- servational uncertainties in hydroclimate forcings. The goal of this paper is to implement a data-driven modeling framework for assessing the sensitivity of ANN-based groundwater forecasts to the uncertainties in observational inputs across space, time, and hydrological regimes. The objectives are two-folded. The first objective is to couple an ANN model with the PAWN sensitivity analysis (SA). The second objective …


Biological Systems Engineering, Asmaa Abdella, Fernando Segato, Mark R. Wilkins Apr 2020

Biological Systems Engineering, Asmaa Abdella, Fernando Segato, Mark R. Wilkins

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The present work studied the optimization of aeration rate, agitation rate and oxygen transfer and the use of various batch fermentation strategies for xylanase production from a recombinant Aspergillus nidulans strain in a 3 L stirred tank reactor. Maximum xylanase production of 1250 U/mL with productivity of 313 U/mL/day was obtained under an aeration rate of 2 vvm and an agitation rate of 400 rpm using batch fermentation. The optimum volumetric oxygen transfer coefficient (kLa) for efficient xylanase production was found to be 38.6 h1. Fed batch mode and repeated batch fermentation was also performed with kLa was 38.6 h1. …


Water Scarcity And Fish Imperilment Driven By Beef Production, Brian D. Richter, Dominique Bartak, Peter Caldwell, Kyle Fankel Davis, Peter Debaere, Arjen Y. Hoekstra, Tianshu Li, Landon Marston, Ryan Mcmanamay, Mesfin Mekonnen, Benjamin L. Ruddell, Richard R. Rushforth, Tara J. Troy Apr 2020

Water Scarcity And Fish Imperilment Driven By Beef Production, Brian D. Richter, Dominique Bartak, Peter Caldwell, Kyle Fankel Davis, Peter Debaere, Arjen Y. Hoekstra, Tianshu Li, Landon Marston, Ryan Mcmanamay, Mesfin Mekonnen, Benjamin L. Ruddell, Richard R. Rushforth, Tara J. Troy

Daugherty Water for Food Global Institute: Faculty Publications

Human consumption of freshwater is now approaching or surpassing the rate at which water sources are being naturally replenished in many regions, creating water shortage risks for people and ecosystems. Here we assess the impact of human water uses and their connection to water scarcity and ecological damage across the United States, identify primary causes of river dewatering and explore ways to ameliorate them. We find irrigation of cattle-feed crops to be the greatest consumer of river water in the western United States, implicating beef and dairy consumption as the leading driver of water shortages and fish imperilment in the …


Evaluation Of The Embedded Environmental Impacts Of The Sanitary Sewer System Using Life Cycle Assessment, Kimberly Law Apr 2020

Evaluation Of The Embedded Environmental Impacts Of The Sanitary Sewer System Using Life Cycle Assessment, Kimberly Law

UCARE: Research Products

This study identifies the overall impact that the installation and construction phase of sanitary sewer systems have on the environment. Construction data on sanitary sewer systems from small Nebraska communities was collected and compared to the operating phase of the sanitary sewer. The operating phase is the energy required for the lift station. Analyzing sanitary sewers during their entire life cycle involved the raw materials, infrastructure construction, installation, operation of the system, and maintenance.

Wastewater treatment systems are meant to reduce the negative impact that humans have on the environment. The purpose of the system is to treat and disinfect …


Maize Growth, Yield, Water Productivity And Evapotranspiration Response To Different Irrigation Methods And Amounts And Different Timing And Methods Of Nitrogen Applications, Ali T. Mohammed Apr 2020

Maize Growth, Yield, Water Productivity And Evapotranspiration Response To Different Irrigation Methods And Amounts And Different Timing And Methods Of Nitrogen Applications, Ali T. Mohammed

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

Declining the quantity and quality of freshwater resources in many parts of the world, including Midwestern USA, especially in the light of rapidly growing world’s population and changing climate, imposes significant and, in some cases imminent, challenges for producers, policy- and decision-makers to produce more yield with less water and other inputs, particularly in water scarcity regions.

There is not comprehensive previous research has quantified and evaluated coupled impacts of irrigation rates and nitrogen timing management strategies and their interactions on maize (Zea mays L.) productivity and its various attributed efficiency index metrics under different irrigation methods under the …


Application Of Internal Curing To Improve Concrete Bridge Deck Performance, Arman Abdigaliyev, Yong-Rak Kim, Jiong Hu Apr 2020

Application Of Internal Curing To Improve Concrete Bridge Deck Performance, Arman Abdigaliyev, Yong-Rak Kim, Jiong Hu

Nebraska Department of Transportation: Research Reports

Due to the relatively high cement content and low water-to-cement ratio (w/c) used, bridge deck concrete is prone to premature cracking. Internal curing has been found to greatly reduce the chance of premature cracking as well as concrete deterioration. This research project was intended to develop internally cured bridge deck concrete based on a local mix design in Nebraska. Four different lightweight fine aggregate (LWFA) as internal curing agents were evaluated, and their effects on fresh, mechanical, durability, and shrinkage properties of concrete were studied. To identify the most effective LWFA dosage for shrinkage reduction, different replacement rates of sand …


Correlation Analysis Of Mdss And Newins, Mark R. Anderson, Curtis L. Walker, Nancy Barnhardt, Nathan Rick, Cameron Wunderlin Apr 2020

Correlation Analysis Of Mdss And Newins, Mark R. Anderson, Curtis L. Walker, Nancy Barnhardt, Nathan Rick, Cameron Wunderlin

Nebraska Department of Transportation: Research Reports

Improving winter maintenance is a goal of most transportation agencies including the Nebraska Department of Transportation (NDOT). One approach is to develop a decision support system to aid in the winter maintenance recommendations. Iteris has developed a maintenance decision support system (MDSS) and has teamed up with NDOT to provide winter weather guidance for operations. This report investigates how well the MDSS functions for several routes across Nebraska for different storm systems. The analysis was performed from saved events within MDSS and compared to meteorological observations during different storm events, mainly Colorado or Alberta Clipper type storms that moved through …


Development And Implementation Of A Moving Nondestructive Evaluation Platform For Bridge Deck Inspection, Sepehr Pashoutani, Jinying Zhu, Chungwook Sim, Brian Mazzeo, Spencer Guthrie Apr 2020

Development And Implementation Of A Moving Nondestructive Evaluation Platform For Bridge Deck Inspection, Sepehr Pashoutani, Jinying Zhu, Chungwook Sim, Brian Mazzeo, Spencer Guthrie

Nebraska Department of Transportation: Research Reports

Degradation in concrete bridge decks is typically manifested as rebar corrosion, concrete delamination, and surface cracks. Nondestructive evaluation and testing (NDE/NDT) technologies have been increasingly used in concrete bridge deck evaluation to identify, localize, and quantify deterioration in bridge decks. Each NDE method has its advantages and limitations on the type of defect that can be detected. Therefore, combining multiple NDE technologies is needed in order to give comprehensive and reliable information about the bridge deck condition. For effective application of multiple NDE tests, we need to use automated positioning for each NDE to facilitate post-processing and data fusion of …


Fate And Transport Of Antibiotics And Antibiotic Resistance Genes In Runoff And Soil As Affected By The Timing Of Swine Manure Slurry Application, Renys Enrique Barrios, Himanshu Khuntia, Shannon L. Bartelt-Hunt, John E. Gilley, Amy M. Schmidt Schmidt, Daniel D. Snow, Xu Li Apr 2020

Fate And Transport Of Antibiotics And Antibiotic Resistance Genes In Runoff And Soil As Affected By The Timing Of Swine Manure Slurry Application, Renys Enrique Barrios, Himanshu Khuntia, Shannon L. Bartelt-Hunt, John E. Gilley, Amy M. Schmidt Schmidt, Daniel D. Snow, Xu Li

Department of Civil and Environmental Engineering: Faculty Publications

Land application of swine manure slurry is a common practice to supplement nutrients to soil for crop production. This practice can introduce antibiotic residues and antibiotic resistance genes (ARGs) into the environment. Field testing is critical in identifying manure management practices effective in minimizing the environmental impacts of manure-borne antibiotic and ARGs. The objective of this study was to determine how the timing of swine manure application relative to rainfall events impacts the fate and transport of antibiotics and ARGs in surface runoff and manure-amended soil. Swine manure slurry was either broadcast or injected on test plots in the field. …


Capturing Spatial Variability In Maize And Soybean Using Stationary Sensor Nodes, Jasreman Singh, Derek M. Heeren, Yufeng Ge, Geng Bai Apr 2020

Capturing Spatial Variability In Maize And Soybean Using Stationary Sensor Nodes, Jasreman Singh, Derek M. Heeren, Yufeng Ge, Geng Bai

Department of Agricultural and Biological Systems Engineering: Faculty Publications

• Irrigation in agriculture maximizes crop yield and improves food security globally • Irrigation scheduling is strongly based on the ability to accurately estimate the appropriate amount and timing of water application • The timing of the irrigation can best be informed through the crop canopy stress, and the amount of irrigation is informed through soil moisture depletion

• Developing upper (non-water stressed) and lower (non-transpiring) baselines for irrigated and non-irrigated maize and soybean • Investigating the relationship between the canopy stress and the soil moisture stress

The canopy temperature stress and soil moisture depletion had stronger correlation for non-irrigated …


Eliminating Rebar Splicing In Transverse Joints Of Precast Full Depth Bridge Deck Panels, David Gee Apr 2020

Eliminating Rebar Splicing In Transverse Joints Of Precast Full Depth Bridge Deck Panels, David Gee

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This study looks at the removal of longitudinal rebar splicing when sufficient longitudinal post-tensioning is provided for full-depth precast deck panels for simply supported bridges. Full-depth precast prestressed concrete deck panels are high quality plant produced pretensioned panels. They are often post-tensioned at the site to provide an average net compression in the joint of at least 250 psi due to effective prestress. This is to ensure adequate transfer of load as truck wheels pass over the joint. This net compression on the transverse joint is not explicitly clear by the AASHTO LRFD Bridge Design Specifications. Based on this section, …


Occurrence And Persistence Of Antibiotics Administered To Cattle In A Newly Established Feedlot, Brittany Trejo Apr 2020

Occurrence And Persistence Of Antibiotics Administered To Cattle In A Newly Established Feedlot, Brittany Trejo

Department of Environmental Engineering: Theses and Other Student Research

The common practice of using therapeutic antibiotics in livestock farming is a worldwide phenomenon. Over the last decade, there has been a growing concern of antibiotics entering the environment via animal manure. Similar studies have focused on the occurrence and biological effects of antibiotics in land-applied animal feedlots; however, limited research has been conducted on the occurrence and persistence of antibiotics in animal feedlots. A study was conducted to investigate the occurrence and persistence of four injected antibiotics (ceftiofur enrofloxacin, florfenicol, and tulathromycin) and two continuously fed antibiotics (monensin and tylosin) in feedlot sediment, runoff, and sediment runoff. For antibiotics …


Assessment Of An Automated Calibration Of The Sebal Algorithm To Estimate Dry-Season Surface-Energy Partitioning In A Forest–Savanna Transition In Brazil, Leonardo Laipelt, Anderson Luis Ruhoff, Ayan Santos Fleischmann, Rafael Henrique Bloedow Kayser, Elisa De Mello Kich, Humberto Ribeiro Da Rocha, Christopher Michael Usher Neale Mar 2020

Assessment Of An Automated Calibration Of The Sebal Algorithm To Estimate Dry-Season Surface-Energy Partitioning In A Forest–Savanna Transition In Brazil, Leonardo Laipelt, Anderson Luis Ruhoff, Ayan Santos Fleischmann, Rafael Henrique Bloedow Kayser, Elisa De Mello Kich, Humberto Ribeiro Da Rocha, Christopher Michael Usher Neale

Daugherty Water for Food Global Institute: Faculty Publications

Evapotranspiration (ET) provides a strong connection between surface energy and hydrological cycles. Advancements in remote sensing techniques have increased our understanding of energy and terrestrial water balances as well as the interaction between surface and atmosphere over large areas. In this study, we computed surface energy fluxes using the Surface Energy Balance Algorithm for Land (SEBAL) algorithm and a simplified adaptation of the CIMEC (Calibration using Inverse Modeling at Extreme Conditions) process for automated endmember selection. Our main purpose was to assess and compare the accuracy of the automated calibration of the SEBAL algorithm using two different sources of meteorological …


A Magnetic Γ-Fe2O3@Pani@Tio2 Core–Shell Nanocomposite For Arsenic Removal Via A Coupled Visible-Light-Induced Photocatalytic Oxidation– Adsorption Process†, Yuan Wang, Ping Zhang, Tian Zhang, Gang Xiang, Xinlong Wang, Simo Pehkonen, Shaojun Yuan Mar 2020

A Magnetic Γ-Fe2O3@Pani@Tio2 Core–Shell Nanocomposite For Arsenic Removal Via A Coupled Visible-Light-Induced Photocatalytic Oxidation– Adsorption Process†, Yuan Wang, Ping Zhang, Tian Zhang, Gang Xiang, Xinlong Wang, Simo Pehkonen, Shaojun Yuan

Department of Civil and Environmental Engineering: Faculty Publications

Arsenic polluted groundwater impairs human health and poses severe threats to drinking water supplies and ecosystems. Hence, an efficient method of simultaneous oxidation of As(III) to As(V), and removal of As(V) from water has triggered increasing attention. In this study, a magnetic γ-Fe2O3 core–shell heterojunction nanocomposite was synthesized by means of hydrothermal crystallization of TiO2 on the surface of the magnetic core–shell loaded with polyaniline (γ-Fe2O3@PANI@TiO2). As an efficient photocatalyst coupled with adsorption, γ-Fe2O3@PANI@TiO2 has a high light utilization and good …


Evidence Of Arithmetical Uncertainty In Estimation Of Light And Water Use Efficiency, Meetpal S. Kukal, Suat Irmak Dr. Mar 2020

Evidence Of Arithmetical Uncertainty In Estimation Of Light And Water Use Efficiency, Meetpal S. Kukal, Suat Irmak Dr.

Department of Agricultural and Biological Systems Engineering: Faculty Publications

It was demonstrated that conventional resource use efficiency (RUE) estimation methodology is largely subject to arithmetic weakness. Extensive field research data on aboveground biomass (AGB), absorbed photosynthetically active radiation (APAR), and crop evapotranspiration (ETc) in maize, soybean, sorghum, and winter wheat confirmed this methodological bias for light use efficiency (LUE) and water use efficiency (WUE) estimation. LUE and WUE were derived using cumulated (data aggregates across samplings) and independent (data increments across samplings) approaches. Use of cumulated data yielded strong-but-false correlation between AGB and APAR or Etc, being a statistical artefact. RUE values from an independent (data increments across samplings) …


Predicting Escherichia Coli Loads In Cascading Dams With Machine Learning: An Integration Of Hydrometeorology, Animal Density And Grazing Pattern, Olufemi P. Abimbola, Aaron R. Mittelstet, Tiffany Messer, Elaine D. Berry, Shannon L. Bartelt-Hunt, Samuel Hansen Mar 2020

Predicting Escherichia Coli Loads In Cascading Dams With Machine Learning: An Integration Of Hydrometeorology, Animal Density And Grazing Pattern, Olufemi P. Abimbola, Aaron R. Mittelstet, Tiffany Messer, Elaine D. Berry, Shannon L. Bartelt-Hunt, Samuel Hansen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Accurate prediction of Escherichia coli contamination in surface waters is challenging due to considerable uncertainty in the physical, chemical and biological variables that control E. coli occurrence and sources in surface waters. This study proposes a novel approach by integrating hydro-climatic variables as well as animal density and grazing pattern in the feature selection modeling phase to increase E. coli prediction accuracy for two cascading dams at the USMeat Animal Research Center (USMARC), Nebraska. Predictive models were developed using regression techniques and an artificial neural network (ANN). Two adaptive neuro-fuzzy inference system (ANFIS) structures including subtractive clustering and fuzzy c-means …


Improvement Of Low Traffic Volume Gravel Roads In Nebraska, Richard L. Wood, Yong-Rak Kim, Yijun Liao, Mohammad E. Mohammadi Mar 2020

Improvement Of Low Traffic Volume Gravel Roads In Nebraska, Richard L. Wood, Yong-Rak Kim, Yijun Liao, Mohammad E. Mohammadi

Nebraska Department of Transportation: Research Reports

In the state of Nebraska, over one-third of roadways are unpaved, and consequently require a significant amount of financial and operational resources to maintain their operation. Undesired behavior of surface gravel aggregates and the road surfaces can include rutting, corrugation, and ponding that may lead to reduced driving safety, speed or network efficiency, and fuel economy. This study evaluates the parameters that characterize the performance and condition of gravel roads overtime period related to various aggregate mix designs. The parameters, including width, slope, and crown profiles, are examples of performance criteria. As remote sensing technologies have advanced in the recent …


Synthesis Of Repair Practices Of Damaged Precast/Prestressed Concrete Girders, George Morcous, Richard L. Wood, Antony Mohsen Kamal Masoud Kodsy Mar 2020

Synthesis Of Repair Practices Of Damaged Precast/Prestressed Concrete Girders, George Morcous, Richard L. Wood, Antony Mohsen Kamal Masoud Kodsy

Nebraska Department of Transportation: Research Reports

Bridge girders are constantly subjected to various types of damage during their service life. There is currently limited knowledge or guidelines provided by the NDOT Bridge Office Policies and Procedures (BOPP) regarding the assessment and repair procedures of damaged precast/prestressed concrete girders. This report aims to develop a comprehensive repair manual for precast/prestressed concrete girders subjected to damage caused by over-height vehicular collision and damage located at the girder ends. Over-height vehicular collision damage typically occurs at the middle portion of the exterior girders and the primary concerns are focused on flexural deficiencies. Girder end damage can occur due to …


Banning Carbon Nanotubes Would Be Scientifically Unjustified And Damaging To Innovation, Daniel A. Heller, Prakrit V. Jena, Matteo Pasquali, Kostas Kostarelos, Lucia G. Delogu, Rachel E. Meidl, Slava V. Rotkin, David A. Scheinberg, Robert E. Schwartz, Mauricio Terrones, Yu Huang Wang, Alberto Bianco, Ardemis A. Boghossian, Sofie Cambré, Laurent Cognet, Simon R. Corrie, Philip Demokritou, Silvia Giordani, Tobias Hertel, Tetyana Ignatova, Mohammad F. Islam, Nicole M. Iverson, Anand Jagota, Dawid Janas, Junichiro Kono, Sebastian Kruss, Markita P. Landry, Yan Li, Richard Martel, Shigeo Maruyama, Anton V. Naumov, Maurizio Prato, Susan J. Quinn, Daniel Roxbury, Michael S. Strano, James M. Tour, R. Bruce Weisman, Wim Wenseleers, Masako Yudasaka Mar 2020

Banning Carbon Nanotubes Would Be Scientifically Unjustified And Damaging To Innovation, Daniel A. Heller, Prakrit V. Jena, Matteo Pasquali, Kostas Kostarelos, Lucia G. Delogu, Rachel E. Meidl, Slava V. Rotkin, David A. Scheinberg, Robert E. Schwartz, Mauricio Terrones, Yu Huang Wang, Alberto Bianco, Ardemis A. Boghossian, Sofie Cambré, Laurent Cognet, Simon R. Corrie, Philip Demokritou, Silvia Giordani, Tobias Hertel, Tetyana Ignatova, Mohammad F. Islam, Nicole M. Iverson, Anand Jagota, Dawid Janas, Junichiro Kono, Sebastian Kruss, Markita P. Landry, Yan Li, Richard Martel, Shigeo Maruyama, Anton V. Naumov, Maurizio Prato, Susan J. Quinn, Daniel Roxbury, Michael S. Strano, James M. Tour, R. Bruce Weisman, Wim Wenseleers, Masako Yudasaka

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In a recent correspondence, the Swedish non-profit organization ChemSec announced the addition of carbon nanotubes to the SIN (‘Substitute It Now’) list1. Carbon nanotubes were added as an entire material class that “should be restricted or banned in the EU.” We believe that this recommendation confuses researchers and the public as it is based on evidence from a very narrow subset of data. Such a designation will likely hinder innovations that could lead to safe and effective applications of carbon nanotubes. Furthermore, this line of reasoning could damage other fields of science and technology, if applied similarly. We have worked …


Risk And Cost Assessment Of Nitrate Contamination In Domestic Wells, Pongpun Juntakut, Erin M.K. Haacker, Daniel D. Snow, Chittaranjan Ray Feb 2020

Risk And Cost Assessment Of Nitrate Contamination In Domestic Wells, Pongpun Juntakut, Erin M.K. Haacker, Daniel D. Snow, Chittaranjan Ray

Daugherty Water for Food Global Institute: Faculty Publications

This study combines empirical predictive and economics models to estimate the cost of remediation for domestic wells exceeding suggested treatment thresholds for nitrates. A multiple logistic regression model predicted the probability of well contamination by nitrate, and a life cycle costing methodology was used to estimate costs of nitrate contamination in groundwater in two areas of Nebraska. In south-central Nebraska, 37% of wells were estimated to be at risk of exceeding a threshold of 7.5 mg/L as N, and 17% were at risk of exceeding 10 mg/L as N, the legal limit for human consumption in the United States. In …


Integration Of Sodium Hypochlorite Pretreatment With Co-Immobilized Microalgae/Bacteria Treatment Of Meat Processing Wastewater, Xinjuan Hu, Yulie Meneses, Ashraf Aly Hassan Feb 2020

Integration Of Sodium Hypochlorite Pretreatment With Co-Immobilized Microalgae/Bacteria Treatment Of Meat Processing Wastewater, Xinjuan Hu, Yulie Meneses, Ashraf Aly Hassan

Department of Food Science and Technology: Faculty Publications

Wastewater with 0.2, 0.4, 0.8, 1.0 mg/L free chlorine was biologically treated using co-immobilized microalgae/ bacteria. In contrast, non-pretreated wastewater was treated with beads (control) and blank beads (blank) under the same operating condition. Results showed that NaClO pretreatment removed 8–33% total nitrogen (TN), 31–45% true color and 0.7–2.5 log CFU/mL aerobic-bacteria. At the end of treatment, maximum algal biomass (2,027 dry weight mg/L) was achieved with 0.2 mg/L free chlorine. Bacterial growth in wastewater was decreased by NaClO pretreatment before reaching 7.2–7.7 log CFU/mL on the fifth day. Beads with microorganisms (control) removed 15% more chemical-oxygen-demand (COD), 16% more …