Remediating Soil For Successful Vegetation Establishment Along Nebraska Highways, Shad Mills, Martha Mamo, Walt Schacht, Humberto Blanco-Canqui

Nebraska Department of Transportation: Research Reports

Vegetation along roadsides is important to prevent soil erosion, provide habitat, and filter water running off the road. Vegetation close to the pavement along highways in Nebraska does not readily establish and persist. It is thought that the sodium and bulk density are the driving factors behind the lack of vegetation. After a construction project the shoulder is seeded into the compacted soil, and during winter salts can accumulate in the soil because of deicing agents being used. The purpose of our study was to determine if the sodium and bulk density are the driving factors of the vegetation cover. …

Establishment Of Wildflower Islands To Enhance Roadside Health And Aesthetics, Walter Schacht, Judy Wu-Smart

Nebraska Department of Transportation: Research Reports

Wildflowers are crucial in the ecological function of the low-input roadside plant communities in terms of water andnutrient cycling, nutrient inputs such as nitrogen, total plant canopy cover, stand longevity, and provision of habitat for numerous small animals. Further, wildflowers provide critical foraging and nesting resources for birds, insects, and other wildlife. Unfortunately, habitat loss from agricultural and urban development has led to rapid population declines in wild bees and other pollinators across the US, thereby jeopardizing not only food production but also the sustainability of our natural landscapes (Kearns & Inouye, 1997). One way to mitigate wild bee decline …

Assessment Of Groundwater Resources In Siwa Oasis, Western Desert, Egypt, Noha H. Moghazy, Jagath J. Kaluarachchi

Civil and Environmental Engineering Faculty Publications

One of the major challenges facing Egypt is limited water resources associated with rapid increase in population. In 1960s, Egyptian government started to use groundwater from the Nubian Sandstone Aquifer System (NSAS) in the Western Desert to expand agricultural sector. Siwa Oasis is the focus of this study to assess the efficiency of groundwater use and corresponding impacts from 1980 to 2012. Results show that from 1980 to 1998, withdrawal from poorly designed wells increased rapidly causing an increase in excess water about 336%. The increase of excess water with the usage of poor drainage produced lakes. Remote Sensing showed …

Removel Of Polluntants From Aqueous Solution Via Graphene Oxide/Magnesium Oxide Nanocomposites, Mahdi Heidarizad

Civil and Environmental Engineering Theses and Dissertations

In this study, a series of graphene oxide/magnesium oxide nanocomposites (GO/MgO NCs) were synthesized and applied for the removal of Methylene Blue (MB) from aqueous solutions. The prepared NCs were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The results showed that MgO particles were successfully layered on GO. The impacts of different experimental variables on the removal of MB including GO/MgO NCs dosage, pH, contact time, and initial MB concentration were investigated.

Thereafter, we investigate the mechanism and kinetics of ozonation processes in the presence of GO/MgO NCs as a catalyst …

Evaluation Of The Mechanisms And Effectiveness Of Nano-Hydroxides, Wood And Dairy Manure-Derived Biochars To Remove Fluoride And Heavy Metals From Water, Anna Rose Wallace, Wenjie Sun Dr, Chunming Su Dr

Civil and Environmental Engineering Theses and Dissertations

The development of effective treatment processes for the removal contaminants, such as fluoride and heavy metals, from polluted water have been urgently needed due to serious environmental health and safety concerns. In this dissertation, a variety of materials including various (hydro)oxide nanomaterials, biochars and surface modified biochar were studied to evaluate their effectiveness and mechanism on removing fluoride or mixed heavy metals from water.

In the Chapter 2, this study investigated the adsorptive removal of fluoride from water using various (hydro)oxide nanomaterials, focusing on ferrihydrite, hydroxyapatite (HAP) and brucite, which have the potential to be used as sorbents for surface …

Utilization Of Low-Lime Calcium Silicate In Hydrated And Carbonated Cementitious Materials, Mohammad Rakibul Islam Khan

Electronic Theses and Dissertations

This study investigated the potential application of wollastonite as a cementitious material in both hydrated and carbonated binder systems. Wollastonite is naturally occurring low-lime calcium silicate (CaO.SiO₂) mineral with a substantially lower carbon footprint compared to the ordinary Portland cement (OPC). The first part of this work presented the application of wollastonite as partial replacement of OPC in traditional hydrated cement-concrete system. Second part of this work evaluated the properties of carbonation activated binder produced using wollastonite as the primary ingredient.

For the first part of the thesis, ground wollastonite with 3.5 µm and 9 µm mean particle …

An Investigation On The Effects Of Cellulose Nanofibrils On The Performance Of Cement Based Composites, Hosain Haddad Kolour

Electronic Theses and Dissertations

Cellulose nanofibrils (CNFs) are hydrophilic biodegradable nanoparticles (typically, less than 0.2 mm in length and 20-50 nm in width) that can be extracted from various plants, trees, and recycled paper stock. Their low density, low toxicity, relatively low cost, high aspect ratio, and high specific surface enable functionalization. In this work, the effects of CNFs on selected properties of cement paste, mortar, and concrete were investigated. For the cement pastes, rheology tests using a simple rheometer showed a reduction in workability as CNF dosage increased. Free shrinkage tests showed an increase in shrinkage at high w/c ratios but a decrease …

A Laboratory Investigation Of Cement Based Materials With Cellulose Nanofibers, Parivash Takasi

Electronic Theses and Dissertations

Cellulose Nanofibers (CNFs) are used as additives in cement-based products to modify their properties. Recent studies about the effects of CNFs on cement paste showed inconsistent results for several different important properties, including compressive strength and free shrinkage. There is reason to believe that the unsystematic results of the compressive strengths were affected by the lack of uniform dispersion of CNFs. As a potential remedy, two different mixing methods were applied. The first method used a basic mixer, but aggregates were added to the cement paste mixture to improve the blending process. The second method utilized a high-speed shear mixer …

Two Clamped Pipe Support Connections For Oil And Gas Brownfield Projects, Helen M. Claycomb

University of New Orleans Theses and Dissertations

In the oil and gas industry, brownfield projects focus on the modification of or addition to an existing production facility that is fully operational and operating. Welding is typically avoided on these projects. The drilling of holes in existing primary structural elements is also prohibited. Clamped connections are often used when adding additional services in a brownfield project. There are different types of clamped connections utilized when a new structural support must be attached to an existing vertical structural pipe. The short bolt clamped connection is a well-established connection and typically used on offshore projects. The U-bolt clamped connection is …

Incorporation Of Unmanned Aerial Vehicle (Uav) Point Cloud Products Into Remote Sensing Evapotranspiration Models, Mahyar Aboutalebi, Alfonso F. Torres-Rua, Mac Mckee, William P. Kustas, Héctor Nieto, Maria Mar Alsina, Alex White, John H. Prueger, Lynn Mckee, Joseph Alfieri, Lawrence E. Hipps, Calvin Coopmans, Nick Dokoozlian

Civil and Environmental Engineering Faculty Publications

In recent years, the deployment of satellites and unmanned aerial vehicles (UAVs) has led to production of enormous amounts of data and to novel data processing and analysis techniques for monitoring crop conditions. One overlooked data source amid these efforts, however, is incorporation of 3D information derived from multi-spectral imagery and photogrammetry algorithms into crop monitoring algorithms. Few studies and algorithms have taken advantage of 3D UAV information in monitoring and assessment of plant conditions. In this study, different aspects of UAV point cloud information for enhancing remote sensing evapotranspiration (ET) models, particularly the Two-Source Energy Balance Model (TSEB), over …

Wintertime Spatial Distribution Of Ammonia And Its Emission Sources In The Great Salt Lake Region, Alexander Moravek, Jennifer G. Murphy, Amy Hrdina, John C. Lin, Christopher Pennell, Alessandro Franchin, Ann M. Middlebrook, Dorothy L. Fibiger, Caroline C. Womack, Erin E. Mcduffie, Randy S. Martin, Kori D. Moore, Munkhbayar Baasandorj, Steven S. Brown

Civil and Environmental Engineering Faculty Publications

Ammonium-containing aerosols are a major component of wintertime air pollution in many densely populated regions around the world. Especially in mountain basins, the formation of persistent cold-air pools (PCAPs) can enhance particulate matter with diameters less than 2.5 µm (PM_2.5) to levels above air quality standards. Under these conditions, PM_2.5 in the Great Salt Lake region of northern Utah has been shown to be primarily composed of ammonium nitrate; however, its formation processes and sources of its precursors are not fully understood. Hence, it is key to understanding the emission sources of its gas phase precursor, ammonia …

Effect Of Recycled Concrete Aggregates On The Long-Term, Elastic, Total Deflection And Strength Of Precast Prestressed Hollow Core Concrete Slabs, Lizeth Marisol Gomez Santana

Civil Engineering Theses

Concrete constitutes the largest portion of construction and demolition waste generated each year in the United States. The Environmental Protection Agency (EPA) estimates that the total production of construction and demolition of concrete waste during 2015 was 381.8 million tons. In order to reduce the economic and environmental effects of waste concrete, researchers have begun to incorporate it into concrete mixtures. However, the inherent variability in mechanical properties between RCA sources makes it difficult to quantify the maximum permissible replacement of natural aggregate and the end-result properties of concrete. This project investigates the use of recycled concrete aggregates (RCA) obtained …

Protocol Efficiently Measuring The Swelling Rate Of Hydrogels, Katherine Zhang, Wuxiang Feng, Congrui Jin

Department of Civil and Environmental Engineering: Faculty Publications

Hydrogels are polymeric materials which can swell in water and retain a significant fraction of water within their structure without dissolving in water. Swelling rate is one of the most important properties of hydrogels. To measure the swelling rate, the profile of swelling capacity versus time of a hydrogel sample is obtained by performing free-absorbency capacity measurements at consecutive time intervals. Traditionally, either the tea-bag method, the sieve method, or the filtration method is used for the free-absorbency capacity measurements depending on the amount of the available sample and the desired precision. However, each method has its own systematic drawbacks. …

An Analysis Of Energy Consumption And The Use Of Renewables For A Small Drinking Water Treatment Plant, Saria Bukhary, Jacimara Batista, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

One of the pressing issues currently faced by the water industry is incorporating sustainability considerations into design practice and reducing the carbon emissions of energy-intensive processes. Water treatment, an indispensable step for safeguarding public health, is an energy-intensive process. The purpose of this study was to analyze the energy consumption of an existing drinking water treatment plant (DWTP), then conduct a modeling study for using photovoltaics (PVs) to offset that energy consumption, and thus reduce emissions. The selected plant, located in southwestern United States, treats 0.425 m3 of groundwater per second by utilizing the processes of coagulation, filtration, and disinfection. …

Concentrations, Sources, And Health Risks Of Particulate Matter In Southeast Us.: Current Status And Future Changes, Fenglin Han

LSU Doctoral Dissertations

Evaluation of long-term air quality trends and prediction of future air quality may help to design and demonstrate effectiveness of control strategies and guide future air quality management. As one of the six criteria air pollutants (CAPs) regulated by the US Environmental Protection Agency (EPA), particulate matter with aerodynamic diameter of 2.5 µm or less (PM_2.5) is of great interests since it has adverse effects on human health, visibility and climate. This study aims to understand the current status and future changes in concentrations, sources, and health risks of PM_2.5 in Southeast US. Firstly, observations were analyzed …

Rheological Models For Non-Newtonian Viscosity Of Modified Asphalt Binders And Mastics, Aboelkasim Diab, Zhanping You, Xuelian Li, Jorge Carvalho Pais, Xu Yang, Siyu Chen

Michigan Tech Publications

This paper is aimed at providing a comprehensive experimental work on the viscosity behavior of different modified asphalt binders and mastics, as well as exploring mathematical representations of the results in attempts to predict the viscosity and flow behaviors according to Vinogradov-Malkin and Phillips-Deutsch models. The modified asphalt binders were prepared in the unaged and aged states using styrene-butadienestyrene (SBS), ethylene-vinyl acetate (EVA), and crumb rubber (CR); while the hydrated lime (HL) and fly ash (FA) were selected to produce the binder-filler mastics. To widen the study findings, the additives (polymers, rubber, and fillers) were applied at different possible levels …

Strengthening Of Corroded Steel Structures Using Cfrp – An Experimental Review, Ghada El-Mahdy Ph.D., P.Eng, Abdallah H. Yassin, Abdel El Rahman Khaled

Civil Engineering

Fibre reinforced polymers (FRP) have been widely used to strengthen reinforced concrete structures, however, nowadays their use to strengthen steel structures is under investigation. In particular, the need to strengthen corroded steel structures found in aggressive environments, such as marine environments, which have undergone a reduction in cross-sectional area and hence a reduction in their load-carrying capacity is in need of studying. The main problems that arise when using carbon fibre reinforced polymer (CFRP) sheets to strengthen steel structures is the weakness in the interfacial bond between the CFRP and the steel surface, the thinness of CFRP sheet, and the …

Sway And No-Sway Behaviour Of Pitched Roof Portal Frames Composed Of Cold-Formed Steel Sections, Ghada El-Mahdy Ph.D, P.Eng., Maged Tawfick Hanna Ph.D

Civil Engineering

Cold-formed sections buckle locally and distortionally in combination with overall buckling of the member. When these sections are incorporated into a portal frame structure, this combination of buckling modes affects the overall buckling behaviour of the portal frame. The objective of this paper is to study the effect of local and distortional buckling on the overall behaviour of portal frames. The portal frames studied have a span of 10 m and an eave height of 3 m with a roof pitch of 1:10. Two frames are studied the first with one intermediate interconnector at the midpoints of the column and …

Self-Healing Of Concrete Under Diverse Environmental Exposure, Ahmed Ramadan Suleiman

Electronic Thesis and Dissertation Repository

Self-healing efficiency of cement-based materials has so far been evaluated mostly through the healing of surface cracks, without adequately capturing the dominant effects of environmental exposure or accurately quantifying the volume of cracks healed. In addition, the effects of diverse additions such as silica-based materials, swelling agents, superabsorbent polymers, and carbonating minerals on self-healing performance under different environmental exposure, remain largely unexplored.

In this dissertation, multiple test methods were used to investigate self-healing of cracks in cement mortar incorporating metakaolin, bentonite, fly ash, superabsorbent polymers, and calcium carbonate microfiller under different environmental exposure (i.e. cold and hot temperatures, high and …

Role Of Groundwater-Lake Interactions On The Behavior Of Chemicals In A Nearshore Aquifer, Sabina Rakhimbekova

Electronic Thesis and Dissertation Repository

It is well recognized that groundwater-surface water interactions play an important role in controlling the flux of groundwater-derived inorganic chemicals to surface waters. While these interactions have been well-studied in marine, and river and stream settings, the influence of these interactions on chemical fluxes to large lakes is poorly understood. Nearshore aquifers adjacent to inland coastal waters, such as the Great Lakes, are characterized by dynamic flow patterns and the mixing of groundwater and lake water, which have distinct chemical compositions. This sets up an important reaction zone in the nearshore aquifer that may modify the fate of groundwater-derived chemicals …

Partial Nitritation Anammox Process For Sidestream Wastewater Treatment In Mabr Technology, Panagiota Stamatopoulou

Electronic Thesis and Dissertation Repository

There has been an increased interest in alternative wastewater treatment systems to improve nutrients removal and energy consumptions while achieving acceptable discharge limits. Wastewater treatment plants (WWTP) have shifted their interest in treating the sidestream wastewater; a reject liquid post anaerobic digestion, rich in ammonium-nitrogen. A dedicated sidestream wastewater treatment unit has become an attractive option with the finding of a relatively new species of bacteria, anaerobic ammonium oxidizers (anammox), able to convert ammonium and nitrite into nitrogen gas. However, anammox bacteria are sensitive in environmental changes, and in combination with their low growth rate, it is challenging to establish …

Human-Infrastructure Interfaces (Hii) Enabled Using Augmented Reality (Ar), Dilendra Maharjan

Civil Engineering ETDs

The modern industrial society is built upon the productivity of advanced computing and agile machines assisting the human workforce to perform their tasks more effectively, accurately and efficiently. The industrial revolution termed as "Industry 4.0" is based on the intelligence of machines working with humans in a collaborative work-space. Contrarily, infrastructure management has relied on the human for making day to day decisions. New emerging technologies can assist during infrastructure inspections, to quantify structural condition with more objective data. However, today's’ owners agree in trusting the inspector's decision in the field over data collected with sensors. If data collected in …

Miniature Cone Penetration Tests With Shear Wave Velocity And Electrical Resistivity Measurements In Characterization Of Silica Sand, Ronit Ganguly

Electronic Thesis and Dissertation Repository

Geotechnical engineering design and analysis require sound identification and characterization of in-situ soil. To characterize is to gather information about the engineering properties of a particular soil which will affect the performance of any structure built on it. As a result of complications associated with the retrieving of undisturbed samples of cohesionless soils, calibration chamber-based experiments under controlled laboratory settings are used for the determination of several geotechnical engineering parameters. The capability of a reduced-scale calibration chamber-based cone penetration testing system along with shear wave velocity and electrical resistivity measurements, to better characterize in-situ soil is examined in this study. …

Anaerobic Digestion Modeling Of A High Rate Acidification Pre-Treatment Technology, Connor Pritty

Electronic Thesis and Dissertation Repository

Through the application of a computerized model (BioWin), anaerobic co-digestion (AcoD) of source separated organics (SSO) and a high rate acidification technology (pretreatment) for a conventional wastewater treatment plant was reviewed. Through this combined approach of high rate acidification, and co-digestion techniques it was found that the experimental modeling scenarios offered increases when compared to the existing base scenario production levels. With the addition of the high rate acidification technology and application of source separated organics the maximum increases in biogas production came when an OLR of 5.24 kg-COD/m³/day and 97g COD/L/d was experimentally modeled. It is therefore, recommended that …

Evaluation Of A Novel Remote Displacement Sensor Prototype Using Video And Laser-Based Technology For Civil Infrastructure Applications, Nicholas J. Brown

Civil and Environmental Engineering Master's Project Reports

Deflection measurements on structures, especially with regards to long-term monitoring, continues to be a challenge with current sensor technologies. Material degradation and changes in the mechanical properties due to aging (for example, creep and shrinkage in concrete bridges) directly impact the deflections exhibited by a structure. In this article we introduce and discuss the evaluation of a novel laser and video-based displacement sensor prototype to monitor displacements and rotations in structures remotely. The sensor is both inexpensive, using off-the shelf components, but also accurate and practical for situations that do not allow the use of conventional displacement sensors, which require …

Flood Dynamics In The Portland Metropolitan Area, Past, Present, And Future, Lumas Terence Helaire

Dissertations and Theses

The Portland area has an extensive flood history since it was founded in 1845. In the late 19th century, the Portland area was prone to flooding from snowmelt freshets (3-6 months duration) and brief winter rain or rain-on-snow events. Since that time the magnitude of spring freshets has been curtailed by 45% due to climate change, flow diversions, and reservoir management. Along with changes in hydrology, the bathymetry of the Lower Columbia River has been altered by the dredging of the navigation channel, diking, and land reclamation. To understand how these changes in hydrology and bathymetry have affected tidal and …

In-Plane Vibration Of Hammerhead Resonators For Chemical Sensing Applications, Luke A. Beardslee, Christopher Carron, Kemal S. Demirci, Jonathan Lehman, Steven Schwartz, Isabelle Dufour, Stephen M. Heinrich, Fabien Josse Phd, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

Thermally excited and piezoresistively detected in-plane cantilever resonators have been previously demonstrated for gas- and liquid-phase chemical and biosensing applications. In this work, the hammerhead resonator geometry, consisting of a cantilever beam supporting a wider semicircular “head”, vibrating in an in-plane vibration mode, is shown to be particularly effective for gas-phase sensing with estimated limits of detection in the sub-ppm range for volatile organic compounds. This paper discusses the hammerhead resonator design and the particular advantages of the hammerhead geometry, while also presenting mechanical characterization, optical characterization, and chemical sensing results. These data highlight the distinct advantages of the hammerhead …

Galena Creek Bridge Structural Health Monitoring Instrumentation And Modeling, Leopold Falkensammer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Structural health monitoring (SHM) of an instrumented structure provides numerous benefits when assessing the long-term condition of the structure against degradation, or the short-term condition after an extreme event, such as an earthquake. The Nevada Department of Transportation (NDOT) has an interest in expanding the use of SHM for such assessments. Accordingly, the objective of the current study is to develop and implement a permanent SHM system for the Galena Creek Bridge, the largest concrete cathedral arch bridge in the world, to monitor its response to routine traffic and seismic activity. Completed in 2012, the bridge connects Reno and Carson …

Treatment Of Perchlorate And Multiple Oxyanions: Chemical And Biological Investigations, Mark Elkouz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Groundwater contamination with oxyanions is an issue that must be addressed for environmental, ecological and societal reasons. Chemical and biological treatment methods of reduction are already known and practiced, but the simultaneous presence of multiple oxyanions can add complicating effects to treatment sequence and efficacy. This research was concerned with the investigation of the chemical reductive treatment of Cr(VI) using both calcium polysulfide (CaSx) and ferrous sulfate (FeSO4), and the biological reductive treatment of chlorate, Cr(VI), nitrate and perchlorate using multiple organic substrates. The chemical treatment phase consisted of initial jar tests, using CaSx and FeSO4, followed by a laboratory …

Alkali-Silica Reactivity Of Mortars Containing Natural Pozzolan, Arash Kian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alkali-silica reactivity is one of the most recognized deleterious phenomena in Portland cement concrete resulting in cracks, spalling, and other deleterious mechanisms.

The aim of this study was (i) to assess the extent of reactivity of the aggregates, quarried from seven different sources, suspected of being conducive to ASR, and (ii) to compare the effectiveness of industrial (Class F fly ash) and natural pozzolans in mitigation of alkali-silica reactivity of the studied aggregates. To this end, seven aggregate sources, four natural pozzolan sources, and one source of Class F fly ash were used. ASTM Type V Portland cement was replaced …