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Articles 91 - 120 of 169

Full-Text Articles in Civil and Environmental Engineering

Development Of Techniques For Assessing And Restoring Streams On Surface Mined Lands, Whitney Cole Blackburn-Lynch Jan 2015

Development Of Techniques For Assessing And Restoring Streams On Surface Mined Lands, Whitney Cole Blackburn-Lynch

Theses and Dissertations--Biosystems and Agricultural Engineering

Surface mining is a commonly used method for extracting coal in the Appalachian Coalfields of the U.S. This mining practice produces excess spoil or overburden, which is often placed in adjacent valleys resulting in the creation of valley fills. These valley fills bury headwater streams, which in turn can negatively impact downstream ecosystems. In 2008, the University of Kentucky designed and constructed 1,020 m of ephemeral, intermittent and headwater streams on an existing valley fill (Guy Cove) as a proof-of-concept. The goal of the project was to evaluate whether or not a stream recreation could occur on mined lands, particularly …


Lateral Torsional Buckling Response In Glass Fiber Reinforced Polymer Composite Beams And Comparison With Ansys Modeling & Design Equations, Santosh Vangala Jan 2015

Lateral Torsional Buckling Response In Glass Fiber Reinforced Polymer Composite Beams And Comparison With Ansys Modeling & Design Equations, Santosh Vangala

Graduate Theses, Dissertations, and Problem Reports (ETD)

Glass fiber reinforced polymer (GFRP) composites have the potential to replace the existing conventional materials in Civil Engineering like steel and concrete. Such potential can be attributed to the numerous advantages GFRP composites have over conventional materials. Some of the advantages are: high strength-to-weight ratio, corrosion resistance, low life cycle cost and maintenance, nonmagnetic and electronic transparency. As the application of GFRP is on the rise, the need for developing accurate design equations for these materials has been imperative. The GFRP composites are manufactured through pultrusion and although they have numerous advantages they are less stiff than similar profiles made …


Assessing Biofiltration Pretreatment For Ultrafiltration Membrane Processes, Andrea Cumming Jan 2015

Assessing Biofiltration Pretreatment For Ultrafiltration Membrane Processes, Andrea Cumming

Electronic Theses and Dissertations

An engineered biological filtration (biofiltration) process treating a nutrient-enriched, low-alkalinity, organic-laden surface water downstream of conventional coagulation-clarification and upstream of an ultrafiltration (UF) membrane process was assessed for its treatment effectiveness. The impact of biofiltration pretreatment on UF membrane performance was evaluated holistically by investigating the native source water chemistry and extending the analysis into the drinking water distribution system. The biofiltration process was also compared in treatment performance to two alternative pretreatment technologies, including magnetic ion exchange (MIEX®) and granular activated carbon (GAC) adsorption. The MIEX®, GAC adsorption, and biologically active carbon (BAC) filtration pretreatments were integrated with conventional …


Micro- And Macro-Scale Modeling Of Filter Aging: Effects Of Particle Poly-Dispersity And Fiber Cross-Sectional Shape, Ahmed M. Saleh Jan 2015

Micro- And Macro-Scale Modeling Of Filter Aging: Effects Of Particle Poly-Dispersity And Fiber Cross-Sectional Shape, Ahmed M. Saleh

Theses and Dissertations

The goal of this study is to further advance the state of the art in developing self-sufficient methods to predict the performance of an aerosol filter. The simulation methods developed in this study are based on first principles and consequently, they do not rely on empirical correction factors. These simulation methods can be used to predict the instantaneous collection efficiency and pressure drop of a filter under dust-loading conditions. In the current study, 3-D micro- and macroscale CFD models are developed to simulate the service life of flat-sheet and pleated filters. These CFD micro- and macroscale models are also used …


Forecasting Corrosion Of Steel In Concrete Introducing Chloride Threshold Dependence On Steel Potential, Andrea Nathalie Sanchez Jul 2014

Forecasting Corrosion Of Steel In Concrete Introducing Chloride Threshold Dependence On Steel Potential, Andrea Nathalie Sanchez

USF Tampa Graduate Theses and Dissertations

Corrosion initiates in reinforced concrete structures exposed to marine environments when the chloride ion concentration at the surface of an embedded steel reinforcing bar exceeds the chloride corrosion threshold (CT) value. The value of CT is generally assumed to have a conservative fixed value ranging from 0.2% to - 0.5 % of chloride ions by weight of cement. However, extensive experimental investigations confirmed that CT is not a fixed value and that the value of CT depends on many variables. Among those, the potential of passive steel embedded in concrete is a key influential factor on the value of CT …


Modeling-As-A-Service (Maas) Using The Cloud Services Innovation Platform (Csip), Olaf David, Wes Lloyd, Ken Rojas, Mazdak Arabi, Frank Geter, James Ascough, Tim Green, G. Leavesley, Jack Carlson Jun 2014

Modeling-As-A-Service (Maas) Using The Cloud Services Innovation Platform (Csip), Olaf David, Wes Lloyd, Ken Rojas, Mazdak Arabi, Frank Geter, James Ascough, Tim Green, G. Leavesley, Jack Carlson

International Congress on Environmental Modelling and Software

Cloud infrastructures for modelling activities such as data processing, performing environmental simulations, or conducting model calibrations/optimizations provide a cost effective alternative to traditional high performance computing approaches. Cloud-based modelling examples emerged into the more formal notion: "Model-as-a-Service" (MaaS). This paper presents the Cloud Services Innovation Platform (CSIP) as a software framework offering MaaS. It describes both the internal CSIP infrastructure and software architecture that manages cloud resources for typical modelling tasks, and the use of CSIP's "ModelServices API" for a modelling application. CSIP's architecture supports fast and resource aware auto-scaling of computational resources. An example model service is presented: the …


Interactive Web-Based Flood Modeling At Country Wide Scale And Plantar Size Resolution, Fedor Baart, Jack Ha, Arthur Van Dam, Gennadii Donchyts, Martijn Siemerink Jun 2014

Interactive Web-Based Flood Modeling At Country Wide Scale And Plantar Size Resolution, Fedor Baart, Jack Ha, Arthur Van Dam, Gennadii Donchyts, Martijn Siemerink

International Congress on Environmental Modelling and Software

The flooding of rural and urban areas is an increasing hazard to society. Accurate and timely predictions are essential for the water manager to prepare and respond to these hazards. Predicting flooding requires a numerical model that represents the physical processes (rain, evaporation, infiltration, overland flow, groundwater flow). This model, fed with measurements, and possible measures, calculates the expected flooding. The traditional working method consists of a three step process: schematization setup, running and post-processing, with a total feedback time of hours. This process is suitable for confirmatory modeling. Most of the time, models are applied exploratory, requiring a different …


Slides: Understanding The Impacts: Issues Of Research, Cindy Beeler Jun 2014

Slides: Understanding The Impacts: Issues Of Research, Cindy Beeler

Water and Air Quality Issues in Oil and Gas Development: The Evolving Framework of Regulation and Management (Martz Summer Conference, June 5-6)

Presenter: Cindy Beeler, U.S. Environmental Protection Agency, Denver, CO

10 slides


Fema Region Iii Coastal Flood Study - Hampton Roads Adaptation Forum, Robin Danforth Mar 2014

Fema Region Iii Coastal Flood Study - Hampton Roads Adaptation Forum, Robin Danforth

March 28, 2014: Addressing Current and Future Vulnerability through Floodplain Management

No abstract provided.


Analyses Of Groundwater Contribution To A Riverine Wetland, Farzad Mahmoodinobar Jan 2014

Analyses Of Groundwater Contribution To A Riverine Wetland, Farzad Mahmoodinobar

Dissertations

Rainfall, runoff, overbank flow and groundwater, all contribute water to wetlands. Each transport element is associated with unique modeling approaches and uncertainties. Transpiration is perhaps the hardest to quantify as it is subject to all the variability of plant growth. Transpiration causes land area to lose moisture and the loss amount depends on precipitation incidence, the temperature and type and extent of vegetation. Plants can intercept virtually all recharge during the growing season and almost none from late fall to early spring in northeastern United States. Thus, an improvement in the transpiration element can contribute considerably to an improved groundwater …


Role Of Solids Retention Time On Complete Nitrification: Mechanistic Understanding And Modeling, Guoqiang Liu, Jianmin Wang Jan 2014

Role Of Solids Retention Time On Complete Nitrification: Mechanistic Understanding And Modeling, Guoqiang Liu, Jianmin Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Effects of solids retention time (SRT) on both steps of the nitrification process (e.g., ammonia oxidation and nitrite oxidation) and the nitrifier community in a complete-mix activated sludge process were studied. At a SRT less than or equal to 20 days, the effluent ammonia concentration was lower than the effluent nitrite concentration. At the 40-day SRT, however, the effluent nitrite concentration became equal to or less than the effluent ammonia concentration. Quantitative Polymerase Chain Reaction (QPCR) assays indicated that increasing SRT significantly increased nitrite-oxidizing bacteria/ammonia-oxidizing bacteria (NOB/AOB) ratio. Further investigation indicated that Nitrosomonas europaea/eutropha were the dominant AOB for ammonia …


Coupled Sediment Yield And Sediment Transport Model To Support Navigation Planning In Northeast Brazil, Calvin Trebor Creech Jan 2014

Coupled Sediment Yield And Sediment Transport Model To Support Navigation Planning In Northeast Brazil, Calvin Trebor Creech

Wayne State University Dissertations

Deposition of sediment (shoaling) in commercial waterways is a major obstacle to maintaining sustainable riverine transportation of bulk goods (primarily agricultural and mining commodities). The rate of aggradation of sediment in a waterway is directly related to both the rate of sediment erosion from upland and river bank sources (sediment yield) and the energy in the river to effectively transport the sediment through the waterway system (sediment transport). Historically, methods used for waterway development have included trial and error or rules of thumb associated with river training structures and chute cut-off canals or engineering of navigation locks and dams. More …


Renovation Of Ammonia Contaminated Produced Water Using Constructed Wetlands, Donald Beebe Aug 2013

Renovation Of Ammonia Contaminated Produced Water Using Constructed Wetlands, Donald Beebe

All Dissertations

Pilot-scale wetland treatment systems were designed and constructed to evaluate renovation of simulated oilfield produced water contaminated with ammonia (20 mg/L ammonia-N). A process-based pilot-scale constructed wetland was designed to meet specific biogeochemical conditions for conversion of ammonia to nitrogen gas through microbial nitrification and denitrification. The process-based constructed wetland treated the simulated produced water to meet stringent discharge requirements (less than 1.2 mg/L ammonia-N). Clinoptilolite, a zeolite mineral, was evaluated for use in constructed wetlands to increase ammonia sorption and nitrification activity. Clinoptilolite increased wetland ammonia sorption capacity and served as a microbial carrier for nitrifying bacteria when ranges …


Using Qual2kw As A Decision Support Tool: Considerations For Data Collection, Calibration, And Numeric Nutrient Criteria, Andrew J. Hobson May 2013

Using Qual2kw As A Decision Support Tool: Considerations For Data Collection, Calibration, And Numeric Nutrient Criteria, Andrew J. Hobson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Surface water quality in the United States is managed by the U.S. Environmental Protection Agency (EPA) under direction of the Clean Water Act. Designated uses are required for all state waters. Numeric or narrative water quality standards provide measures to determine if each waterbody meets the intended use. Narrative standards typically include vague terminology that is difficult to interpret and this has led EPA to encourage states to develop numeric criteria for nutrients in all its streams, rivers, and lakes. These numeric nutrient criteria are intended to stave off the harmful effects of over-growth of aquatic plants which can result …


Compositional Characterization Of Soil Organic Matter And Hot-Water Extractable Organic Matter In Organic Horizons Using A Molecular Mixing Model, Ankit Balaria, Chris E. Johnson Apr 2013

Compositional Characterization Of Soil Organic Matter And Hot-Water Extractable Organic Matter In Organic Horizons Using A Molecular Mixing Model, Ankit Balaria, Chris E. Johnson

Civil and Environmental Engineering - All Scholarship

Purpose Microbial decomposition of soil organic matter (SOM) is generally believed to be heterogeneous, resulting in the preferential loss of labile compounds such as carbohydrates and proteins and the accumulation of recalcitrant compounds such as lipids and lignin. However, these fractions are difficult to measure directly in soils. We examined patterns in the biomolecular composition of SOM and hot-water-extractable organic matter (HWEOM) by using a molecular mixing model (MMM) to estimate the content of carbohydrates, protein, lipids, and lignin.

Materials and methods Organic-horizon soils from Spodosols at the Hubbard Brook Experimental Forest in New Hampshire, USA were analyzed for this …


City Of Norfolk Coastal Flood Mitigation Program, Brian Joyner Mar 2013

City Of Norfolk Coastal Flood Mitigation Program, Brian Joyner

March 13, 2013: Regional Sea Level Rise Assessment, Adaptation and Flood Mitigation Projects

No abstract provided.


Fema Region Iii Coastal Storm Surge Study, Mike Forte, Jeff Hanson, Michelle Hamor Mar 2013

Fema Region Iii Coastal Storm Surge Study, Mike Forte, Jeff Hanson, Michelle Hamor

March 13, 2013: Regional Sea Level Rise Assessment, Adaptation and Flood Mitigation Projects

No abstract provided.


Willoughby Spit Shoreline Improvement Project Of Ocean View Beach, Maura Boswell Mar 2013

Willoughby Spit Shoreline Improvement Project Of Ocean View Beach, Maura Boswell

March 13, 2013: Regional Sea Level Rise Assessment, Adaptation and Flood Mitigation Projects

No abstract provided.


Testing Above- And Below-Canopy Representations Of Turbulent Fluxes In An Energy Balance Snowmelt Model, Vinod Mahat, David G. Tarboton, Noah P. Molotch Jan 2013

Testing Above- And Below-Canopy Representations Of Turbulent Fluxes In An Energy Balance Snowmelt Model, Vinod Mahat, David G. Tarboton, Noah P. Molotch

T.W. "Doc" Daniel Experimental Forest

Turbulent fluxes of sensible and latent heat are important processes in the surface energy balance that drives snowmelt. Modeling these fluxes in a forested environment is complicated because of the canopy effects on the wind field. This paper presents and tests a turbulent flux model developed to represent these processes in an energy balance snowmelt model. The goal is to model these processes using the readily available inputs of canopy height and leaf area index in a way that minimizes the number of parameters, state variables, and assumptions about hard to quantify processes. Selected periods from 9 years of eddy-covariance …


Testing Above- And Below-Canopy Representations Of Turbulent Fluxes In An Energy Balance Snowmelt Model, Vinod Mahat, David G. Tarboton, Noah P. Molotch Jan 2013

Testing Above- And Below-Canopy Representations Of Turbulent Fluxes In An Energy Balance Snowmelt Model, Vinod Mahat, David G. Tarboton, Noah P. Molotch

Civil and Environmental Engineering Faculty Publications

Turbulent fluxes of sensible and latent heat are important processes in the surface energy balance that drives snowmelt. Modeling these fluxes in a forested environment is complicated because of the canopy effects on the wind field. This paper presents and tests a turbulent flux model developed to represent these processes in an energy balance snowmelt model. The goal is to model these processes using the readily available inputs of canopy height and leaf area index in a way that minimizes the number of parameters, state variables, and assumptions about hard to quantify processes. Selected periods from 9 years of eddy-covariance …


Distribution And Occurrence Of Escherichia Coli In Water And Sediments At Grand Glaize Beach In Lake Of The Ozarks State Park, Jordan Lee Wilson Jan 2013

Distribution And Occurrence Of Escherichia Coli In Water And Sediments At Grand Glaize Beach In Lake Of The Ozarks State Park, Jordan Lee Wilson

Masters Theses

"Public swimming beaches at the Lake of the Ozarks State Park (LOSP) are popular vacationing spots for many Missourians; however, on several occasions Escherichia coli (E. coli) concentrations have exceeded standards set by the Missouri Department of Natural Resources (MDNR). Exceedances lead to beach closures which not only represent a potential public health threat but are also detrimental to the local economy and the public's perception of the lake's general water quality. In a collaborative effort between Missouri S&T, the United States Geological Survey (USGS) and the MDNR, an in-depth, two-summer study was conducted which included collection of …


Effect Of Cement Chemistry And Properties On Activation Energy, Andre J. Bien-Aime Jan 2013

Effect Of Cement Chemistry And Properties On Activation Energy, Andre J. Bien-Aime

USF Tampa Graduate Theses and Dissertations

The objective of this work is to examine the effect of cement chemistry and physical properties on activation energy. Research efforts indicated that time dependent concrete properties such as strength, heat evolution, and thermal cracking are predictable through the concept of activation energy. Equivalent age concept, which uses the activation energy is key to such predictions. Furthermore, research has shown that Portland cement concrete properties are affected by particles size distribution, Blaine fineness, mineralogy and chemical composition. In this study, four Portland cements were used to evaluate different methods of activation energy determination based on strength and heat of hydration …


Effect Of Localized Corrosion Of Steel On Chloride-Induced Concrete Cover Cracking In Reinforced Concrete Structures, Ezeddin Rafaa Busba Jan 2013

Effect Of Localized Corrosion Of Steel On Chloride-Induced Concrete Cover Cracking In Reinforced Concrete Structures, Ezeddin Rafaa Busba

USF Tampa Graduate Theses and Dissertations

Abstract: Concrete cover cracking due to reinforcement corrosion is widely accepted as a limit-state indicator in defining the end of functional service life for existing reinforced concrete (RC) structures undergoing corrosion. Many of the currently available durability prediction models are incapable of providing realistic estimates of remaining service lives of RC structures beyond the corrosion initiation point. Therefore, the need to incorporate the length of the corrosion propagation stage in a comprehensive durability prediction approach has recently received much research attention. Previous research focus however was mostly limited to the case of uniformly corroding reinforcement with only few studies addressing …


Investigation Of Mercury Use, Release, Deposition, And Exposures In The Tampa Bay Area, Ryan Algernon Michael Jan 2013

Investigation Of Mercury Use, Release, Deposition, And Exposures In The Tampa Bay Area, Ryan Algernon Michael

USF Tampa Graduate Theses and Dissertations

I investigate the links between mercury use, release, deposition, and population exposure in Tampa Bay, with the focus of identifying levers for reducing population mercury exposures. To achieve this, I investigated the trends in mercury use and release by products and processes in the Tampa Bay area using a Material Flow Analysis. Analysis of USEPA National Emissions Inventory data over time (1999 - 2008) identified relevant air source emission categories, and explored and compared state and regional trends in mercury emissions. To understand source contributions to wet deposited mercury in the Tampa Bay area, I analyzed trends in mercury deposition …


Advancing Cyberinfrastructure To Support High Resolution Water Resources Modeling (Invited), David G. Tarboton, F. L. Ogden, N. Jones, Jeffery S. Horsburgh Dec 2012

Advancing Cyberinfrastructure To Support High Resolution Water Resources Modeling (Invited), David G. Tarboton, F. L. Ogden, N. Jones, Jeffery S. Horsburgh

Civil and Environmental Engineering Faculty Publications

Addressing the problem of how the availability and quality of water resources at large scales are sensitive to climate variability, watershed alterations and management activities requires computational resources that combine data from multiple sources and support integrated modeling. Related cyberinfrastructure challenges include: 1) how can we best structure data and computer models to address this scientific problem through the use of high-performance and data-intensive computing, and 2) how can we do this in a way that discipline scientists without extensive computational and algorithmic knowledge and experience can take advantage of advances in cyberinfrastructure? This presentation will describe a new system …


Hydraulic Modeling: Pipe Network Analysis, Trevor T. Datwyler Dec 2012

Hydraulic Modeling: Pipe Network Analysis, Trevor T. Datwyler

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Water modeling is becoming an increasingly important part of hydraulic engineering. One application of hydraulic modeling is pipe network analysis. Using programmed algorithms to repeatedly solve continuity and energy equations, computer software can greatly reduce the amount of time required to analyze a closed conduit system. Such hydraulic models can become a valuable tool for cities to maintain their water systems and plan for future growth. The Utah Division of Drinking Water regulations require cities to maintain hydraulic models of their culinary water systems, and before additional connections can be made to the water system, a licensed professional engineer must …


Reverse Osmosis Desalination With Integrated Compressed Air Energy Storage: Conceptual Design And Modeling, Pooja Mahajan Dec 2012

Reverse Osmosis Desalination With Integrated Compressed Air Energy Storage: Conceptual Design And Modeling, Pooja Mahajan

All Theses

Growing fresh water needs have led to an interest in water desalination using reverse osmosis (RO) membranes. Energy consumption has a large share in the expenses incurred to drive a reverse osmosis desalination system. With depleting fossil fuel reserves, tapping renewable sources of energy is a promising alternative to meet the energy requirements. Wind power coupled to an RO desalination system is a potential means of delivering clean water using sustainable energy. This work investigates modeling of a conceptual wind-energy-driven RO desalination system that is made possible because of an air-pressure energy storage mechanism. Bench-scale experiments were performed on an …


Analysis Of Irrigation Decision Behavior And Forecasting Future Irrigation Decisions, Sanyogita Andriyas Dec 2012

Analysis Of Irrigation Decision Behavior And Forecasting Future Irrigation Decisions, Sanyogita Andriyas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Farmers play a pivotal role in food production. To be economically successful, farmers must make many decisions during the course of a growing season about the allocation of inputs to production. For farmers in arid regions, one of these decisions on any given day is whether to irrigate. This research is the first of its kind to investigate the probable reasons that lead a farmer to make irrigation decisions and use those reasons/factors to forecast future irrigation decisions. This study can help water managers and canal operators to estimate short-term irrigation demands, thereby gaining information that might be useful to …


Modeling Potential Hydrochemical Responses To Climate Change And Increasing Co2 At The Hubbard Brook Experimental Forest Using A Dynamic Biogeochemical Model (Pnet-Bgc), Afshin Pourmokhtaria, Charles T. Driscoll, John L. Campbell, Katharine Hayhoe Jul 2012

Modeling Potential Hydrochemical Responses To Climate Change And Increasing Co2 At The Hubbard Brook Experimental Forest Using A Dynamic Biogeochemical Model (Pnet-Bgc), Afshin Pourmokhtaria, Charles T. Driscoll, John L. Campbell, Katharine Hayhoe

Civil and Environmental Engineering - All Scholarship

Dynamic hydrochemical models are useful tools for understanding and predicting the interactive effects of climate change, atmospheric CO2, and atmospheric deposition on the hydrology and water quality of forested watersheds. We used the biogeochemical model, PnET-BGC, to evaluate the effects of potential future changes in temperature, precipitation, solar radiation, and atmospheric CO2 on pools, concentrations, and fluxes of major elements at the Hubbard Brook Experimental Forest in New Hampshire, United States. Future climate projections used to run PnET-BGC were generated specifically for the Hubbard Brook Experimental Forest with a statistical technique that downscales climate output (e.g., air temperature, precipitation, solar …


Using Ground Penetrating Radar Signal Reflection To Model A Highly Transmissive Bedrock Aquifer, Daniel J. Brockmeyer Mr. May 2012

Using Ground Penetrating Radar Signal Reflection To Model A Highly Transmissive Bedrock Aquifer, Daniel J. Brockmeyer Mr.

Master's Theses

The use of numerical modeling software to characterize groundwater contaminant fate and transport requires an understanding of the distribution of hydraulic properties of the aquifer. As the complexity of this distribution increases, a more sophisticated understanding is required. Modeling contaminant transport in bedrock aquifers requires that the spatial distributions of highly conductive geologic features are characterized along with the hydraulic transmissivities of those features (Shapiro, 2003). The goal of this research is to refine the numerical model of a highly transmissive crystalline aquifer by characterizing the spatial variability of the hydraulic transmissivity using the attenuation of the ground penetrating radar …