A Snapshot Of Sars-Cov-2 In Wastewater Treatment Plants In Northwest Arkansas,
2022
University of Arkansas, Fayetteville
A Snapshot Of Sars-Cov-2 In Wastewater Treatment Plants In Northwest Arkansas, Katie Loethen
Biological and Agricultural Engineering Undergraduate Honors Theses
Because SARS-CoV-2, a coronavirus, is released in the fecal shedding of covid-positive patients, the virus enters the municipal waste stream and flows to wastewater treatment plants (WWTPs). The goal of this research is to quantify the effectiveness of wastewater treatment processes at removing SARS-CoV-2 from wastewater and preventing its release into the environment. Sampling at Paul R. Noland and West Side WWTPs in Fayetteville, Arkansas, took place from August 2020 to May 2021, and samples were tested for the presence of SARS-CoV-2 using N1 and N2 primers via RT-qPCR. Sampling days which returned positive detection of one or both of …
Wind Flow Characteristics Of Multi-Vortex Tornadoes And Their Wind Effects On Residential Houses,
2022
Missouri University of Science and Technology
Wind Flow Characteristics Of Multi-Vortex Tornadoes And Their Wind Effects On Residential Houses, Yi Zhao
Doctoral Dissertations
"Tornadoes strike the USA very frequently, with an average of 1200 reports per year, and the average annual tornado-induced property loss has reached $10B. The devastation from recent tornadoes have prompted a renewed interest in better understanding tornado dynamics, their interactions with the built environment, and the performance of civil structures during tornadoes. In the past, the wind effects caused by single-vortex tornadoes have been widely studied, while the multi-vortex tornadoes were rarely considered. In fact, many previous deadly, costly tornadoes involved multiple vortices. Therefore, it is important to understand the wind flow characteristics of multi-vortex tornadoes in order to …
Fabrication Of Lab-Scale Polymeric And Silicon Dioxide Nanoparticle-Enabled Thin Film Composite Reverse Osmosis Membranes For Potable Reuse Applications,
2022
California Polytechnic State University, San Luis Obispo
Fabrication Of Lab-Scale Polymeric And Silicon Dioxide Nanoparticle-Enabled Thin Film Composite Reverse Osmosis Membranes For Potable Reuse Applications, Timothy J. Dinh
Master's Theses
Reverse osmosis (RO) is widely used for water reclamation and is one of the most feasible technologies for addressing water scarcity around the world. RO membrane fabrication procedures are continually being optimized and modified to enhance the treatment performance and efficacy of the RO process. A review of the existing literature published on membrane fabrication revealed that a detailed and reproducible methodology consistent among prior studies was not available. Therefore, the primary objective of this study was to utilize techniques from prior research to develop a reliable lab-scale membrane fabrication process for studying the potable reuse applications of TFC RO …
Efficiency Of Bank Filtration In The Removal Of Cyanotoxins Under Different Levels Of Nutrients,
2022
University of Nebraska-Lincoln
Efficiency Of Bank Filtration In The Removal Of Cyanotoxins Under Different Levels Of Nutrients, Luke Walkenhorst
Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research
Harmful Algal Blooms (HABs) are an increasing concern not only in Nebraska, but across the world. Increasing global temperatures in conjunction with overuse of synthetic fertilizers are leading causes to the increasing frequency and concern of HABs. In the present work, the effectiveness of simulated bank filtration (BF), as an economical water treatment option, to remove cyanotoxins under different levels of nutrients (nitrates and phosphates) was investigated. Vertical flow-through columns pre-acclimated with two levels of nutrients (e.g., nitrate and phosphate—10 vs. 50 mg/L) were exposed to two different levels of cyanotoxins (10 vs. 75 μg/L). Results from the study confirmed …
Ds-Menet For The Classification Of Citrus Disease,
2022
Missouri University of Science and Technology
Ds-Menet For The Classification Of Citrus Disease, Xuyao Liu, Yaowen Hu, Guoxiong Zhou, Weiwei Cai, Mingfang He, Jialei Zhan, Yahui Hu, Liujun Li
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Affected by various environmental factors, citrus will frequently suffer from diseases during the growth process, which has brought huge obstacles to the development of agriculture. This paper proposes a new method for identifying and classifying citrus diseases. Firstly, this paper designs an image enhancement method based on the MSRCR algorithm and homomorphic filtering algorithm optimized by Laplacian (HFLF-MS) to highlight the disease characteristics of citrus. Secondly, we designed a new neural network DS-MENet based on the DenseNet-121 backbone structure. In DS-MENet, the regular convolution in Dense Block is replaced with depthwise separable convolution, which reduces the network parameters. The ReMish …
Construction And Operation Of A Pilot-Scale Odor Control Device,
2022
University of Nebraska-Lincoln
Construction And Operation Of A Pilot-Scale Odor Control Device, Brendan Bunker
Department of Environmental Engineering: Theses and Other Student Research
Hydrogen sulfide (H2S) is a naturally occurring by-product of anaerobic digestion and causes an odor that can be a nuisance and a public health risk at higher concentrations. This compound can be treated through various means, but one of particular interest is a biotrickling filter (BTF). Such devices have excellent H2S treatment efficiencies, but start-up costs can be steep. The primary goal of this study is to explain the design and operation of a low-cost odor control device for improving environmental air quality in Nebraska using a BTF. This device has the potential for application as …
Wetland Soil Development Along Salinity And Hydrogeomorphic Gradients In Active And Inactive Deltaic Basins Of Coastal Louisiana,
2022
Louisiana State University and Agricultural and Mechanical College
Wetland Soil Development Along Salinity And Hydrogeomorphic Gradients In Active And Inactive Deltaic Basins Of Coastal Louisiana, Amanda Fontenot
LSU Master's Theses
Coastal wetlands provide an abundance of ecosystem services that benefit society, such as essential habitat for commercial species, storm protection, nutrient cycling, and carbon storage. Louisiana faces rapid rates of relative sea level rise (natural subsidence and eustatic sea levels) that threaten wetland survival, which are amplified by a reduction of riverine sediment input. An important determining factor of marsh survival is the formation of wetland platform elevation, known as vertical accretion, which is determined by several processes including sediment deposition & erosion, below ground biomass (BGB) productivity, decomposition of organic matter, shallow & deep subsidence, and soil compaction. Feldspar …
Development An Edge-Computing Sensing Unit For Continuous Measurement Of Canopy Cover Percentage Of Dry Edible Beans,
2022
University of Nebraska-Lincoln
Development An Edge-Computing Sensing Unit For Continuous Measurement Of Canopy Cover Percentage Of Dry Edible Beans, Wei-Zhen Liang, Joseph Oboamah, Xin Qiao, Yufeng Ge, Robert M. Harveson, Daran R. Rudnick, Jun Wang, Haishun Yang, Angie Gradiz
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Canopy cover (CC) is an important indicator for crop development. Currently, CC can be estimated indirectly by measuring leaf area index (LAI), using commercially available hand-held meters. However, it does not capture the dynamics of CC. Continuous CC monitoring is essential for dry edible beans production since it can affect crop water use, weed, and disease control. It also helps growers to closely monitor “yellowness”, or senescence of dry beans to decide proper irrigation cutoff to allow the crop to dry down for harvest. The goal of this study was to develop a device – CanopyCAM, containing software and hardware …
Effect Of Bromoform And Linseed Oil On Greenhouse Gas Emissions From Stored Beef Manure,
2022
University of Nebraska-Lincoln
Effect Of Bromoform And Linseed Oil On Greenhouse Gas Emissions From Stored Beef Manure, Andrew Ortiz Balsero, Mara Zelt, Amy Millmier Schmidt, Miguel Fudolig, Daniel N. Miller
Department of Agricultural and Biological Systems Engineering: Faculty Publications
Emissions of carbon dioxide, methane, and nitrous oxide – potent greenhouse gases - from stored beef feedlot manure are a significant concern relative to climate change. Research on methane reduction strategies for enteric emissions has identified the application of organic additives, such as bromoform and linseed oil, to ruminant diets as potential solutions for reducing enteric emissions and pathogenic bacteria in excreted manure. The objective of this study was to determine the effect of bromoform and linseed oil on greenhouse gas emissions from beef feedlot manure, and on E. coli concentration in beef cattle manure, during a 5-week storage period. …
Elemental Sulfur And Metal Sulfide Minerals For Autotrophic Denitrification: Applications To Aquaculture, Groundwater Treatment, And Domestic Wastewater Treatment,
2022
University of South Florida
Elemental Sulfur And Metal Sulfide Minerals For Autotrophic Denitrification: Applications To Aquaculture, Groundwater Treatment, And Domestic Wastewater Treatment, Erica Amah Dasi
USF Tampa Graduate Theses and Dissertations
Nutrient pollution of waterways, from excess N and P, is a global concern that results in harmful impacts the environment, human health, and aquatic animals. This dissertation harnesses sulfur autotrophic denitrification to remove nutrients from groundwater, domestic wastewater, and wastewaters produced from marine recirculating aquaculture systems (RAS). Part 1 evaluates the denitrification performance of woodchips and elemental sulfur in cyclic denitrification filters (WS-CDFs) integrated into marine RAS operated under saline conditions. Part 2 investigates the use of metal sulfide minerals, with and without oyster shells, for supporting nutrient removal from groundwater in batch reactors. Part 3 assesses …
Learning From Machines: Insights In Forest Transpiration Using Machine Learning Methods,
2022
Portland State University
Learning From Machines: Insights In Forest Transpiration Using Machine Learning Methods, Morgan Thornwell
Dissertations and Theses
Machine learning has been used as a tool to model transpiration for individual sites, but few models are capable of generalizing to new locations without calibration to site data. Using the global SAPFLUXNET database, 95 tree sap flow data sites were grouped using three clustering strategies: by biome, by tree functional type, and through use of a k-means unsupervised clustering algorithm. Two supervised machine learning algorithms, a random forest algorithm and a neural network algorithm, were used to build machine learning models that predicted transpiration for each cluster. The performance and feature importance in each model were analyzed and compared …
Mdam-Drnet: Dual Channel Residual Network With Multi-Directional Attention Mechanism In Strawberry Leaf Diseases Detection,
2022
Missouri University of Science and Technology
Mdam-Drnet: Dual Channel Residual Network With Multi-Directional Attention Mechanism In Strawberry Leaf Diseases Detection, Tingjing Liao, Ruoli Yang, Peirui Zhao, Wenhua Zhou, Mingfang He, Liujun Li
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The growth of strawberry plants is affected by a variety of strawberry leaf diseases. Yet, due to the complexity of these diseases' spots in terms of color and texture, their manual identification requires much time and energy. Developing a more efficient identification method could be imperative for improving the yield and quality of strawberry crops. To that end, here we proposed a detection framework for strawberry leaf diseases based on a dual-channel residual network with a multi-directional attention mechanism (MDAM-DRNet). (1) In order to fully extract the color features from images of diseased strawberry leaves, this paper constructed a color …
Investigating The Proper Use Of Litani River Basin Based On Water Quality,
2022
Beirut Arab University
Investigating The Proper Use Of Litani River Basin Based On Water Quality, Mohamad Diab, Mohamad Soliman
BAU Journal - Science and Technology
Litani River Basin (LRB) with a 170km length and annual river flow of 750 MCM is considered the most important water resource in Lebanon. Unfortunately, the river is facing water contamination as a result of human practices. Water Quality assessments was performed in the Litani River Basin using a combination of Principal Component Analysis method (PCA) and Water Quality Index method (WQI). Results revealed the improvement of the water quality significantly after passing lake Qaraoun. Moreover, according to WQI, Lower LRB water is ranked ‘’Good’’ for irrigation and ‘’BAD’ for drinking purposes. Microbial contamination is found to be the key …
Mechanical And Durability Properties Of Geopolymer Concrete – A Review,
2022
Engineer, Department of Civil & Environmental Engineering, Faculty of Engineering, Beirut Arab University
Mechanical And Durability Properties Of Geopolymer Concrete – A Review, Lelian Elkhatib, Fadi Al Aridi, Adel Elkordi, Jamal Khatib
BAU Journal - Science and Technology
Owing to the ongoing increase in human population, there is a need for more construction projects including residential buildings and other amenities. Concrete is by far the dominant material used in construction and cement is a main ingredient. Cement manufacture is an energy intensive process and emit large amounts of carbon dioxide into the atmosphere. A reduction in the amount of cement used in construction is greatly beneficial. The use of geopolymer or alkali activated materials can serve this purpose as it attempts to totally replace cement in concrete. Geopolymers are materials that consist mainly of silica and alumina materials …
Modified Biosand Filtration Using Aluminum Hydroxide Filter Media To Enhance Fluoride Removal,
2022
University of South Florida
Modified Biosand Filtration Using Aluminum Hydroxide Filter Media To Enhance Fluoride Removal, Joshelyn Guimaray
USF Tampa Graduate Theses and Dissertations
There are over 20 countries whose citizens consume groundwater containing high levels of fluoride, including Nigeria, Mexico, India, China, and Ghana, which all have major health crises when it comes to the safety of their drinking water. Minerals like fluorite contain fluoride which is often found in groundwater aquifers. The minerals release fluoride into the groundwater. Per the World Health Organization (WHO) standard, the maximum contaminant limit for fluoride consumption should be less than 1.5 mg/L. Chronic exposure of elevated levels of fluoride can cause people to suffer debilitating health effects, such as dental and skeletal fluorosis. Dental fluorosis causes …
A Convergent Approach To Aqueous Lead (Pb) Mitigation Of A Supplemental Self-Supply Shallow Groundwater Source Accessed By Handpumps In Madagascar,
2022
University of South Florida
A Convergent Approach To Aqueous Lead (Pb) Mitigation Of A Supplemental Self-Supply Shallow Groundwater Source Accessed By Handpumps In Madagascar, Adaline Marie Buerck
USF Tampa Graduate Theses and Dissertations
The World Health Organization (WHO) has consistently listed lead (Pb) as one of the ten chemicals of major public health concern. Though the toxic nature of lead has been known since the 20th century it is still utilized in a wide variety of products due to its favorable properties. Exposure to lead still accounts for approximately 900,000 deaths annually and disproportionately impacts those in low- and middle-income countries (LMIC) due to a variety of reasons such as poverty, malnutrition, and lack of knowledge on the toxic nature of lead. Lead exposure routes include air, soil, dust, diet, and water. Though …
Fragmentation Of Chemically Herded Oil Slicks By Obstacles: Visualizations, Flow Measurements, And Spatial Distributions,
2022
University of South Florida
Fragmentation Of Chemically Herded Oil Slicks By Obstacles: Visualizations, Flow Measurements, And Spatial Distributions, Ali Alshamrani
USF Tampa Graduate Theses and Dissertations
Chemical herders are a promising technique for treatment of oil spills in icy waters at high latitudes. However, obstacles on the water surface such as floating ice affects or interferes with all spill response countermeasures including chemical herder operations by fracturing the contracting oil slick and trapping small oil patches. Chemical herders are likely to be especially useful in containing oil spills in remote, ice-infested Arctic waters, where using booms to contain an oil slick is difficult. Much of the previous research into chemical herder has focused on the effectiveness of different types of chemical herder agents to thicken oil …
Exploring Toluene Biosynthesis In Microbial Consortia Derived From Sediments And Superfund Site Groundwater,
2022
Louisiana State University and Agricultural and Mechanical College
Exploring Toluene Biosynthesis In Microbial Consortia Derived From Sediments And Superfund Site Groundwater, Raymond J. Poche
LSU Master's Theses
While the aromatic hydrocarbon toluene is widely regarded as a contaminant associated with discharges of crude oil and refined petroleum products (e.g., gasoline), the enzyme phenylacetate decarboxylase catalyzes the decarboxylation of phenylacetate to yield toluene. Research described in this thesis further investigated toluene biosynthesis by a microbial consortium originating from chlorinated solvent-contaminated groundwater near Baton Rouge, Louisiana. In anoxic growth media supplemented with phenylacetate as a precursor, toluene accumulation was found to be maximal at near-neutral to slightly acidic pHs (toluene accumulation greater than 1 mg/L at pH in the range of 5.6 to 7.6, but was not observed for …
Evaluation Of Aluminum Dissolution, Current Density, And Pitting Patterns During Electrocoagulation,
2022
University of South Florida
Evaluation Of Aluminum Dissolution, Current Density, And Pitting Patterns During Electrocoagulation, Monica Castro Carias
USF Tampa Graduate Theses and Dissertations
Electrocoagulation (EC) is a sustainable water treatment process involving the generation of coagulants on-site through the application of a voltage on metal (usually aluminum or iron alloys). The factors that impact EC system performance have been well researched, however further research is needed on the factors that impact anodic dissolution of aluminum electrodes, especially when the technology is transferred to full-scale applications. Electrode fouling is one of the factors that can impact dissolution of the anode during EC due to the formation of a protective oxide/hydroxide layer on the electrode surface. Previous studies have addressed electrode fouling by reversing polarity, …
Design And Commissioning Of An E-Beam Irradiation Beamline At The Upgraded Injector Test Facility At Jefferson Lab,
2022
Old Dominion University
Design And Commissioning Of An E-Beam Irradiation Beamline At The Upgraded Injector Test Facility At Jefferson Lab, Xi Li, Helmut Baumgart, Charles Bott, Gianluigi Ciovati, Shaun Gregory, Fay Hannon, Mike Mccaughan, Robert Pearce, Matthew Poelker, Hannes Vennekate, Shaoheng Wang
Electrical & Computer Engineering Faculty Publications
The Upgraded Injector Test Facility (UITF) at Jefferson Lab is a continuous-wave superconducting linear accelerator capable of providing an electron beam with energy up to 10 MeV. A beamline for electron-beam irradiation has been designed, installed and successfully commissioned at this facility, aimed at the degradation study of 1,4-dioxane and per- and polyfluoroalkyl substances (PFAS) in wastewater treatment. A solenoid with a peak axial magnetic field of up to 0.28 T and a set of raster coils were used to obtain a Gaussian beam profile with a transverse standard deviation of ∼15.0 mm at the target location. Monte-Carlo simulations using …
