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Articles 1 - 27 of 27
Full-Text Articles in Engineering
Calcium Ferrite As A Semiconductor For Microbially Assisted Photocatalytic Reduction Of Carbon Dioxide, Lauren King
Calcium Ferrite As A Semiconductor For Microbially Assisted Photocatalytic Reduction Of Carbon Dioxide, Lauren King
Honors Scholar Theses
The pressing issue of global climate change has been found to be attributed to the increasing concentration of greenhouse gases in the atmosphere, especially carbon dioxide. One mitigation idea to close the carbon loop is to utilize redox reactions and photocatalysis to reduce carbon dioxide to a useable fuel source, like methane or methanol. This thesis will study the possibility of using calcium ferrite as the semiconductor to perform photocatalytic reduction of carbon dioxide with the assistance of a microbial fuel cell, which will help minimize the energy required from sunlight photons. A calcium ferrite thin film was produced through …
Modeling And Monitoring Of Water Quantity And Quality In Permeable Pavement Systems Using Geophysical Equipment, Abby Klimowicz
Modeling And Monitoring Of Water Quantity And Quality In Permeable Pavement Systems Using Geophysical Equipment, Abby Klimowicz
Honors Scholar Theses
Permeable pavements are a type of low impact development (LID) that reduces runoff by increasing the permeability of developed surfaces. Less runoff helps protect the surrounding ecosystems from erosion and pollution. Without pools of accumulating runoff, the potential for the development of ice on roads and parking lots is also decreased. However, sufficient research on the movement of water and the ions dissolved in it through the permeable pavement system has not been completed. In this study, geophysical equipment was used to observe how moisture, measured as volumetric water content (VWC), and ions, approximated by electrical conductivity, pass through constructed …
Household Income And Air Pollution At Public Schools In The United States, Katyland Facas, Kristina Wagstrom
Household Income And Air Pollution At Public Schools In The United States, Katyland Facas, Kristina Wagstrom
Honors Scholar Theses
Poor air quality at schools may negatively impact students’ academic performance.1 2 3 In this study we look at the relationship between ambient, outdoor air quality and student socioeconomic status at United States public schools. We used free and reduced lunch eligibility, as part of the USDA’s National School Lunch Program, as an indicator of household income. We focus on nitrogen dioxide (NO2), ozone (O3), and particulate matter smaller than 2.5 microns (PM2.5). We used ambient pollutant concentration estimates at census block group resolution (Kim et al.) as the outdoor air pollution concentration at each school.4 We found a positive …
Promoting The Sustainable Utilization Of Groundwater Resources In Ethiopia Using The Integrated Groundwater Footprint Index, Xinyu Lin
Honors Scholar Theses
The country of Ethiopia is highly vulnerable to human-caused climate change and is already suffering from the effects. The predominately rural population relies heavily on small-scale agriculture, with 78% of households having at least one member engaged in the field, yet staple crops are highly susceptible to droughts and other weather shocks. Total and agricultural GDP growth in the country have been strongly linked to inter-annual rainfall variability, of which Ethiopia has among the highest in sub-Saharan Africa. A decrease in rainfall since the 1970s has been one of the primary causes of low crop yields, and stresses the immediate …
Investigation Of Activated Carbon And Protein Polysaccharide Amendments In Capping Applications For Sediment Remediation, Mehdi Begag
Honors Scholar Theses
Contaminated sediment is a major environmental problem in numerous sites across the US and requires costly treatment to effectively remediate the sediment and prevent contaminants from entering the water column. Capping of contaminated sediment has emerged as the preferred treatment design as it is more cost effective and effectively isolates the contaminants in-situ. Powdered Activated Carbon (PAC) is commonly introduced in capping designs due to its high sorption capacity of organic contaminants. However, its low bulk density and fine particle size result in significant carbon resuspension during cap placement. This report provides experimental and modeling results focused on the effects …
Stretchable Methyl Ammonium Lead Iodide Perovskite Solar Cells For Photovoltaic And Piezoelectric Energy Harvesting, William Tait
Stretchable Methyl Ammonium Lead Iodide Perovskite Solar Cells For Photovoltaic And Piezoelectric Energy Harvesting, William Tait
University Scholar Projects
The goal of this work was to fabricate an inverse planar perovskite solar cell (PSC) that was stretchable in one dimension and completely solution-processible. Perovskites are a material that have attracted much attention in recent years due to their appealing characteristics, such as being photovoltaic and piezoelectric. PSCs have been the focus of many studies in the solar cell area, as they are solution-processible and have shown high efficiencies relative to the amount of time they have been studied. Fabricating a PSC on a stretchable substrate would be beneficial, as a bendable, stretchable PSC would likely have more applications than …
Stability And Redispersion Of Platinum Nanoparticle Suspensions For Attachment To Dyes In Low-Cost Solar Cells, Jeffrey Rothstein
Stability And Redispersion Of Platinum Nanoparticle Suspensions For Attachment To Dyes In Low-Cost Solar Cells, Jeffrey Rothstein
Honors Scholar Theses
The project involves optimizing the synthesis, washing, and redispersion of platinum nanoparticles. The nanoparticles are to be attached to dye molecules where they will act as nanocatalysts to reduce energy losses in low-cost dye-sensitized solar cells. The goal is to develop a process based on a pure or mixed solvent that will maintain a stable dispersion of the nanoparticles without interfering with their ability to bond with the dye molecules in the solar cell.
Hydrogeological Conceptual Model Of La Villa River Watershed, Republic Of Panama, Maria G. Castrellon Romero
Hydrogeological Conceptual Model Of La Villa River Watershed, Republic Of Panama, Maria G. Castrellon Romero
Honors Scholar Theses
Groundwater in Panama is a valuable and poorly understood resource. Its exploitation has increased 75% in the past decade, reaching a total value of 700,000 m3/day or 185 million gallons per day (MGD). Climate change has caused a lengthening of the dry season, which has reduced precipitation and streamflow, resulting in surface water scarcity during this period. Nevertheless, it has not been possible to determine the extent to which groundwater sources have been affected by these factors since systematic monitoring of groundwater levels has not been implemented in Panama. With support from National Institution of Drinking Water Supply …
Quantum Mechanical Modeling Of Organic-Oxide Surface Complexation Reactions, Brianna Datti
Quantum Mechanical Modeling Of Organic-Oxide Surface Complexation Reactions, Brianna Datti
Honors Scholar Theses
Recent advancements in agriculture, industry, and pharmaceutical formulations have increased the presence of organic contaminants in the environment. It is important and necessary to study and understand the processes which control the environmental fate and transformation of contaminants and improve removal and remediation techniques. The use of advanced quantum mechanical modeling is a promising technique to better understand the mechanisms of adsorption within the environment. Relative Gibbs free energy values of adsorption have been calculated using such modeling for selected organic acids sorption to iron oxides, revealing the thermodynamic favorability of each of the reactions, except one involving bidentate mononuclear …
Investigation Of In-Situ Immobilization Of Contaminated Sediments Using Alginate Gels For The Reduction Of Ecological Risk, Michael V. Podany Mr.
Investigation Of In-Situ Immobilization Of Contaminated Sediments Using Alginate Gels For The Reduction Of Ecological Risk, Michael V. Podany Mr.
Master's Theses
Remediation methods for contaminated sediments include dredging, treatment and disposal and sediment isolation through capping. These methods are costly and adversely impact local ecosystems, in some cases causing major disturbances to the sediment bed and water column. A new remediation technique is proposed for slowly biodegradable contaminants using alginate hydrogels as a binding agent of sediment. The rational is that sediment particles bound in alginate hydrogel are less likely to be resuspended and the treatment is less disruptive than capping. Here we show addition of alginate increased the shear strength of sediment comprised of defined particle sizes. The increase in …
Weather-Based Damage Prediction Models For Electric Distribution Networks, David W. Wanik
Weather-Based Damage Prediction Models For Electric Distribution Networks, David W. Wanik
Master's Theses
From thunderstorms to hurricanes, electric distribution networks are subject to a wide range of warm weather storm events. Tropical Storm Irene (2011) and Hurricane Sandy (2012) are two events in recent memory that disrupted over half of The Connecticut Light and Power Company’s (CL&P) service territory, which left some customers without power for up to eleven days. This research study investigates a damage prediction framework for both thunderstorms and hurricanes that combines two generalized linear models to probabilistically determine the occurrence and extent of damages, known as trouble spots, to the overhead power distribution network. The models are inputted with …
Using Nwp Analysis In Satellite Rainfall Estimation Of Heavy Precipitation Events Over Complex Terrain, Xinxuan Zhang
Using Nwp Analysis In Satellite Rainfall Estimation Of Heavy Precipitation Events Over Complex Terrain, Xinxuan Zhang
Master's Theses
This study investigates the use of Weather Research and Forecasting (WRF) high-resolution storm analysis in satellite rainfall estimation over complex terrains. Rainfall estimation here is based on the NOAA-Climate Prediction Center morphing (CMORPH) product. Specifically, CMORPH rainfall is adjusted by applying a power-law function whose parameter values are obtained from the comparison between WRF and CMORPH hourly rain rates. Results are presented based on the analyses of five storm cases that induced catastrophic floods in southern Europe. The WRF-based adjusted CMORPH rain rates exhibited improved error statistics against independent radar-rainfall estimates. We show that the adjustment reduces the underestimation of …
Impact Of Salt On Denitrification Potential In Roadside Environments, Nakita A. Lancaster
Impact Of Salt On Denitrification Potential In Roadside Environments, Nakita A. Lancaster
Master's Theses
Urban systems are impacted by changes in hydrology and water chemistry, altering their ability to mitigate detrimental impacts to coastal water bodies, particularly those that result from high volumes of stormwater runoff. The elevated level of impervious cover increases not only runoff but also contaminant loading of nutrients, metals, and road salt used for deicing in cold weather climates. Current stormwater management strategies, while focused on managing the changes in hydrology associated with urbanization, also are designed to mitigate the pollutant loading. Here we investigate the impact that road salt will have on nitrogen removal in roadside environments. Sediments were …
Rainfall Organization And Geomorphologic Controls On The Flood Response Of Mild-Slope Basins In The South Atlantic Region Of Us, Yiwen Mei
Master's Theses
This study uses data from the Tar-River Basin in North Carolina to explore how space-time rainfall variability influences the hydrologic response from observational and modeling perspectives. For understanding the basin scale effect, the Tar-River Basin is divided into four cascade sub-basins ranging from 1106 km2 up to 5654 km2. The study evaluates the catchments’ response to rainfall for a large number of storm events by computing the event runoff coefficient based on streamflow observations and through simulations from a semi-distributed hydrological model. Comparison of observed to simulated hydrographs from the hydrological model shows that distributed rainfall forcing …
Using Ground Penetrating Radar Signal Reflection To Model A Highly Transmissive Bedrock Aquifer, Daniel J. Brockmeyer Mr.
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 …
Bias Correction And Downscaling Of Climate Model Outputs Required For Impact Assessments Of Climate Change In The U.S. Northeast, Kazi F. Ahmed
Bias Correction And Downscaling Of Climate Model Outputs Required For Impact Assessments Of Climate Change In The U.S. Northeast, Kazi F. Ahmed
Master's Theses
Global Climate Models (GCMs) are the typical sources of future climate data required for impact assessments of climate change. However, GCM outputs are related to model-related uncertainties and involve a great deal of biases. Bias correction of model outputs is, therefore, necessary before their use in impact studies. The coarse resolution of GCM simulations is another hindrance to their direct use in fine-scale impact analysis of climate change. Although downscaling of GCM outputs can be performed by dynamical downscaling using Regional Climate Models (RCMs), it requires large computational capacity. When daily climate data from multiple GCMs are required to be …
Understanding Formation And Transport Of Amorphous Iron Oxyhydroxides In Porous Media Using Microfluidic Flow Cells- A Novel Method To Study Freshwater Iron Cycling, Neha A. Ghaisas
Master's Theses
The ground water and surface water interface (GSI or Hyporheic zone) is a spatially- and temporally-fluctuating biogeochemical transition zone connecting these two distinct hydrological components. The mixing zone is characterized by a near neutral pH, ambient temperature and a sharp oxygen concentration which in turn has deep impact on the iron cycling and thus the fate of contaminants in the water column. We constructed an experimental micromodel that to observe key processes that affect biogeochemical iron cycling in the fresh water interface zones where the oxic surface water mixes with Fe (II) rich underlying ground water. The flow cell was …
A Field And Modeling Assessment Of Methyl Mercury Accumulation In An Engineered Retention Pond, Lauren C. Blazeck
A Field And Modeling Assessment Of Methyl Mercury Accumulation In An Engineered Retention Pond, Lauren C. Blazeck
Master's Theses
The accumulation of methyl mercury (MeHg) in lakes during summer stratification has been demonstrated to affect biotic mercury (Hg) accumulation. However, small, shallow polymictic lakes can experience short-term stratification and mixing events that are largely unstudied in their abilities to affect Hg cycling and MeHg accumulation. Short-term stratification events and changing lake characteristics impact lake biogeochemical cycles, and therefore, MeHg production and transport. A field and modeling analysis was performed on a small suburban lake located on the University of Connecticut campus to determine the impact of lake characteristics on the potential for MeHg accumulation. MeHg concentrations ranged from non-detect …
Dissolved Organic Matter Characterization And Impact On Mercury Binding In An Urbanizing Watershed, Mykel Mendes
Dissolved Organic Matter Characterization And Impact On Mercury Binding In An Urbanizing Watershed, Mykel Mendes
Master's Theses
Dissolved organic matter (DOM) is ubiquitous in aquatic ecosystems, interacting with and controlling the bioavailability and transport of mercury (Hg) and other trace metals through complexation. The complexation of ionic Hg (Hg2+) with DOM can either limit methyl mercury (MeHg) bioavailability or increase MeHg production by stimulating microbial growth. While substantial investigations have examined Hg-DOM interactions in forested ecosystems, little research has been conducted on the Hg-DOM relationship within an urbanized river setting subjected to various anthropogenic sources. The various runoff and pollutant sources vary in DOM quality and character. Three sources of organic matter from the North …
Constitutive Model For Rate Dependent Behavior Of Clay Internal Geotechnical Report 2011-3, Harry Martindale, Dipanjan Basu
Constitutive Model For Rate Dependent Behavior Of Clay Internal Geotechnical Report 2011-3, Harry Martindale, Dipanjan Basu
Technical Reports
This report presents a strain-rate dependent plastic constitutive model for clays. Based on the concepts of critical-state soil mechanics and bounding surface plasticity theory, the model reproduces the mechanical response of clays under multi-axial loading conditions and predicts both the drained and undrained behavior. The model parameters are determined for Boston Blue Clay, London Clay and Kaolin Clay, and the performance of the model in simulating the mechanical response of these clays is demonstrated for low to medium strain rates. The sensitivity of each model parameter is checked by perturbing the calibrated values by ±20%. Subsequently, a probabilistic analysis using …
A High Strain-Rate Constitutive Model For Sand With Application In Finite Element Analysis Internal Geotechnical Report 2011-4, William Higgins, Dipanjan Basu
A High Strain-Rate Constitutive Model For Sand With Application In Finite Element Analysis Internal Geotechnical Report 2011-4, William Higgins, Dipanjan Basu
Technical Reports
The report presents a constitutive model for simulating the high strain-rate behavior of sands. Based on the concepts of critical-state soil mechanics, the bounding surface plasticity theory and the overstress theory of viscoplasticity, the constitutive model simulates the high strain-rate behavior of sands under uniaxial, triaxial and multiaxial loading conditions. The model parameters are determined for Ottawa and Fontainebleau sands, and the performance of the model under extreme transient loading conditions is demonstrated through simulations of split Hopkinson pressure bar tests up to a strain rate of 2000/sec. The constitutive model is implemented in a finite element analysis software to …
Possibility Of Consolidated Wetland Mitigation In A Multi-Layered Legislated State, Juan P. Correa
Possibility Of Consolidated Wetland Mitigation In A Multi-Layered Legislated State, Juan P. Correa
Master's Theses
No abstract provided.
Fourier Finite Element Analysis Of Laterally Loaded Piles In Elastic Media Internal Geotechnical Report 2011-1, William Higgins, Dipanjan Basu
Fourier Finite Element Analysis Of Laterally Loaded Piles In Elastic Media Internal Geotechnical Report 2011-1, William Higgins, Dipanjan Basu
Technical Reports
Laterally loaded piles are analyzed using the Fourier finite element method. Pile response was observed to be a function of the relative stiffness of pile and soil and of the pile slenderness ratio. The analysis is mostly performed for piles embedded in elastic soil with constant and linearly varying modulus although the pile response in two-layer soil profiles is also investigated. Equations describing pile head deflection, rotation and maximum bending moment are proposed for flexible long piles and stubby rigid piles. The design equations were developed after plotting the pile responses as functions of pile-soil stiffness ratio and pile slenderness …
Sustainability In Geotechnical Engineering Internal Geotechnical Report 2011-2, Aditi Misra, Dipanjan Basu
Sustainability In Geotechnical Engineering Internal Geotechnical Report 2011-2, Aditi Misra, Dipanjan Basu
Technical Reports
The built environment serves as a dynamic interface through which the human society and the ecosystem interact and influence each other. Understanding this interdependence is key to understanding sustainability as it applies to civil engineering. There is a growing consensus that delivering a sustainable built environment starts with incorporating sustainability thoughts at the planning and design stages of a project. Geotechnical engineering is the most resource intensive of all the civil engineering disciplines and can significantly influence the sustainability of infrastructure development because of its early position in the construction process. In this report, a review is made of the …
Comprehensive Analysis Of Effluent Organic Matter From Five Wastewater Treatment Plants In Connecticut And Comparison To Natural Organic Matter, Matthew L. Quaranta
Comprehensive Analysis Of Effluent Organic Matter From Five Wastewater Treatment Plants In Connecticut And Comparison To Natural Organic Matter, Matthew L. Quaranta
Master's Theses
Natural organic matter is an important driver of biotic and abiotic processes in aquatic environments. Wastewater treatment plants discharge a substantial amount of organic matter into the environment; however effluent organic matter has not been well studied. In this study, traditional organic geochemical techniques were applied to characterize effluent organic matter. Effluent organic matter was isolated by DAX8 (hydrophobic fraction) and XAD4 (transphilic fraction) Amberlite resins. Extraction efficiencies of effluent organic matter by DAX8 resins ranged from 18 to 42 percent as a result of larger content of hydrophilic organic matter than natural organic matter. Average organic matter molecular weights …
The River Discontinuum: Applying Beaver Modifications To Baseline Conditions For Restoration Of Forested Headwaters, Denise Burchsted, Melinda Daniels, Robert Thorson, Jason Vokoun
The River Discontinuum: Applying Beaver Modifications To Baseline Conditions For Restoration Of Forested Headwaters, Denise Burchsted, Melinda Daniels, Robert Thorson, Jason Vokoun
Center for Integrative Geosciences
Billions of dollars are being spent in the United States to restore rivers to a desired, yet often unknown, reference condition. In lieu of a known reference, practitioners typically assume the paradigm of a connected watercourse. Geological and ecological processes, however, create patchy and discontinuous fluvial systems. One of these processes, dam building by North American beavers (Castor canadensis), generated discontinuities throughout precolonial river systems of northern North America. Under modern conditions, beaver dams create dynamic sequences of ponds and wet meadows among free-flowing segments. One beaver impoundment alone can exceed 1000 meters along the river, flood the valley laterally, …
Creating Useful Products From Connecticut's 2000 Lidar Data Set Jhr 08-314 Project 07-2, Thomas H. Meyer
Creating Useful Products From Connecticut's 2000 Lidar Data Set Jhr 08-314 Project 07-2, Thomas H. Meyer
Department of Natural Resources and the Environment Articles
The State of Connecticut owns a LIght Detection and Ranging (LIDAR) data set that was collected in 2000 as part of the State’s periodic aerial reconnaissance missions. Although collected eight years ago, these data are just now becoming ready to be made available to the public. These data constitute a massive “point cloud”, being a long list of east-north-up triplets in the State Plane Coordinate System Zone 0600 (SPCS83 0600), orthometric heights (NAVD 88) in US Survey feet. Unfortunately, point clouds have no structure or organization, and consequently they are not as useful as Triangulated Irregular Networks (TINs), digital elevation …