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Articles 1 - 14 of 14
Full-Text Articles in Engineering
Swat Model Simulation Of Bioenergy Crop Impacts On Water Quality In Cache River Watershed, Eeshan Kumar
Swat Model Simulation Of Bioenergy Crop Impacts On Water Quality In Cache River Watershed, Eeshan Kumar
Graduate Theses and Dissertations
Energy security through increased biofuel production is one of the components of the Energy Independence and Security Act (EISA) 2007. As per EISA 2007 mandate, appropriate independent research institutes are required to assess concerns to natural biodiversity due to biofuel production and report it to the Congress through the Environment Protection Agency (EPA). Planners, researchers, and agencies concerned with environmental regulations, ideally, would like to have location-specific information about the impacts for developing appropriate management interventions. This study examines long-term impacts on water quality in response to targeted (i.e. marginal lands) production of biofuel crops by setting up two SWAT …
Evaluation Of Conservation Practices Through Simulation Modeling And Tool Development, Gurdeep Singh
Evaluation Of Conservation Practices Through Simulation Modeling And Tool Development, Gurdeep Singh
Graduate Theses and Dissertations
For the first objective, predicted impacts of selected Mississippi River Basin Initiative (MRBI) conservation practices (CPs) on sediment and nutrient loss were assessed. The study area was L’Anguille River Watershed (LRW), a priority focus watershed of the MRBI program and the simulated CPs were filter strip, critical area planting, grade stabilization structure, irrigation land leveling, irrigation pipeline, irrigation water management, and nutrient management. The Soil and Water Assessment Tool (SWAT) model was calibrated (1998 – 2005) and validated (2006 – 2012) for flow, sediment, total phosphorus (TP), and nitrate-nitrogen (NO3-N) at the Colt site (503 sq. km. drainage area) and …
Compounds Released From Biomass Deconstruction: Understanding Their Effect On Cellulose Enzyme Hydrolysis And Their Biological Activity, Angele Djioleu
Compounds Released From Biomass Deconstruction: Understanding Their Effect On Cellulose Enzyme Hydrolysis And Their Biological Activity, Angele Djioleu
Graduate Theses and Dissertations
The effect of compounds produced during biomass pretreatment on cellulolytic enzyme was investigated. Liquid prehydrolyzates were prepared by pretreating switchgrass using 24 combinations of temperature, time, and sulfuric acid concentration based on a full factorial design. Temperature was varied from 140°C to 180°C; time ranged from 10 to 40 min; and the sulfuric acid concentrations were 0.5% or 1% (v/v). Identified products in the prehydrolyzates included xylose, glucose, hydroxymethylfurfural (HMF), furfural, acetic acid, formic acid, and phenolic compounds at concentration ranging from 0 to 21.4 g/L. Pretreatment conditions significantly affected the concentrations of compounds detected in prehydrolyzates. When assayed in …
Modified Polysulfone Nanofiltration Membrane Synthesis For Hydraulic Fracturing Water Recycle, Blake Alexander Johnson
Modified Polysulfone Nanofiltration Membrane Synthesis For Hydraulic Fracturing Water Recycle, Blake Alexander Johnson
Graduate Theses and Dissertations
The use of hydraulic fracturing has resulted in significant increases in the yield of oil and natural gas, as water pumped into wells at high pressure cracks the formations and releases the hydrocarbons that are locked in the rocks. This process has created large volumes of brackish water that is very difficult to process and is often disposed of into injection wells. Suspended solids and some dissolved solids are more readily removed, but the multivalent ions found in certain salts can precipitate in a well and complicate the reuse of flowback in future hydraulic fracturing operations.
Nanofiltration, a membrane separation …
An Empirical Water Quality And Best Management Practice Prioritization Model For Select Arkansas Watersheds, James Mccarty
An Empirical Water Quality And Best Management Practice Prioritization Model For Select Arkansas Watersheds, James Mccarty
Graduate Theses and Dissertations
The purpose of this study was to prioritize subwatersheds using water quality data and watershed characteristics. Water quality data was provided through studies by the Arkansas Natural Resources Commission, Beaver Water District, Arkansas Water Resources Center, and publicly available USGS gage data. A total of 114 sites across five HUC-8 watersheds were analyzed, including 12 USGS gages. Watershed characteristic data was retrieved from USGS and Arkansas GeoStore geodatabase repositories. A significant linear relationship between baseflow and stormflow nutrient concentrations was established allowing for the use of baseflow concentrations in the prioritization methodology. Pearson correlation, linear regression, classification and regression tree, …
A Cradle To Farm Gate Life Cycle Analysis Of Land Use In U.S. Pork Production, William Benjamin Putman
A Cradle To Farm Gate Life Cycle Analysis Of Land Use In U.S. Pork Production, William Benjamin Putman
Graduate Theses and Dissertations
The goal of this study was to conduct a detailed Life Cycle Assessment (LCA) of the U.S. live swine production supply chain to quantify land use requirements and to assess the impact associated with various ration compositions. The functional unit was defined as one kilogram (2.2 pounds) of live swine at the farm gate, ready for transport to the abattoir. This assessment focused on the three highest producing USDA regions, which encompassed the Midwest (Regions 5 and 7) and the Southeast (Region 4), representing 86% of U.S. market hog production.
First, a literature review was conducted to summarize the most …
Synthesis Of Palladium And Palladium-Copper Nanostructures As Electrocatalysts, Haibin Wu
Synthesis Of Palladium And Palladium-Copper Nanostructures As Electrocatalysts, Haibin Wu
Graduate Theses and Dissertations
Pd and its alloys are alternatives of Pt as promising catalysts and electrocatalysts for many reactions. Size controlled synthesis of nanoparticles remains a major research subject, since smaller size particles show better catalytic performance. In this work, we developed a modified chemical wet method to prepare Pd and Pd-Cu nanostructures with uniform small size. Different sizes and shapes of Pd nanostructures were successfully synthesized by using the two reducing agents (i.e., L-ascorbyl-6-palmitate or phenylphosphinic acid). The reducing agents play a role to control the final morphologies and sizes of particles. The use of L-ascorbyl-6-palmitate favors to form irregular branch shapes …
Using The Triple Bottom Line To Select Sustainable Suppliers For A Major Oil And Gas Company, Pandarinath Adarsh Sunkari
Using The Triple Bottom Line To Select Sustainable Suppliers For A Major Oil And Gas Company, Pandarinath Adarsh Sunkari
Graduate Theses and Dissertations
Companies have primarily been focusing on the financial bottom line i.e., on increasing profits by increasing revenues and reducing costs. With high energy usage and environmental change posing threats to the environment and business operations, companies are now considering sustainability. Since some global suppliers have low cost labor, Social well-being and human development has also emerged as major goals of a company performing global operations. Focusing on these three goals is termed the "Triple Bottom Line" (TBL). We study and explore the TBL benefits that could be realized by an oil and gas company by focusing on sustainable suppliers. A …
A Pump Monitoring Approach To Irrigation Pumping Plant Performance Testing, William Merritt Mcdougall
A Pump Monitoring Approach To Irrigation Pumping Plant Performance Testing, William Merritt Mcdougall
Graduate Theses and Dissertations
Traditionally, irrigation pumping plants have been tested using an instantaneous appraoch, which tests performance parameters over a very short time interval. Using this method, the tester measures the necessary work and energy use parameters to calculate the desired pumping plant performance values. The primary limitation of this approach is its inability to determine the season long efficiency of an irrigation pumping plant.
A new approach to evaluating irrigation pumping plant performance is the use of pump monitoring systems which use high frequency, real-time data collection and telemetry to relay information directly from the pump to the user. This method of …
Top-Down Aluminum Induced Crystallization For Photovoltaics, Seth Daniel Shumate
Top-Down Aluminum Induced Crystallization For Photovoltaics, Seth Daniel Shumate
Graduate Theses and Dissertations
Passivating silicon solar cell surfaces is critical to fabricating very high efficiency and low cost photovoltaic devices. The sun-facing surface of the solar cell, known as the emitter, is particularly important when designing a solar cell. This work focused first on an alternative method of forming the emitter of silicon solar cells, and secondly on a method for improving the surface passivation of both these non-traditional and standard n-type solar cells.
Top-down aluminum induced crystallization (TAIC) was used for forming a polycrystalline silicon layer from amorphous silicon using aluminum to catalyze the crystallization at much lower temperatures than otherwise possible. …
Enhancement Of The Performance Of Gaas Based Solar Cells By Using Plasmonic, Anti-Reflection Coating And Hydrophobic Effects, Yahia Fayiz Makableh
Enhancement Of The Performance Of Gaas Based Solar Cells By Using Plasmonic, Anti-Reflection Coating And Hydrophobic Effects, Yahia Fayiz Makableh
Graduate Theses and Dissertations
Investigation of renewable energy resources is gaining huge momentum in recent years due to the limited fossil fuels, and their detriment impact on the environment. Solar energy is promising to meet the increased energy demand. In order to achieve this goal, solar energy has to be harvested efficiently at low cost. Therefore, higher efficiency solar cells are the primary focus of research worldwide. Photovoltaics based on InAs/GaAs intermediate band solar cells and their device performance enhancements are investigated in this dissertation. The device enhancement is carried out by surface modification methods. The dissertation work is inspired by the need of …
Transformation Of Swine Manure And Algal Consortia To Value-Added Products, Mahmoud A. Sharara
Transformation Of Swine Manure And Algal Consortia To Value-Added Products, Mahmoud A. Sharara
Graduate Theses and Dissertations
The swine production sector is projected to grow globally. In the past, this growth manifested itself in increased herd sizes and geographically concentrated production. Although economically sound, these trends had negative consequences on surrounding ecosystems. Over-application of manure resulted in water quality degradation, while long-term storage of manure slurries was found to promote release of potent GHG emissions. There is a need for innovative approaches for swine manure management that are compatible with current scales of production, and increasingly strict environmental regulations.
This study aims to investigate the potential for incorporating gasification as part of a novel swine manure management …
Experimental Verification And Integration Of A Next Generation Smart Power Management System, Tavis Clemmer
Experimental Verification And Integration Of A Next Generation Smart Power Management System, Tavis Clemmer
Graduate Theses and Dissertations
With the increase in energy demand by the residential community in this country and the diminishing fossil fuel resources being used for electric energy production there is a need for a system to efficiently manage power within a residence. The Smart Green Power Node (SGPN) is a next generation energy management system that automates on-site energy production, storage, consumption, and grid usage to yield the most savings for both the utility and the consumer. Such a system automatically manages on-site distributed generation sources such as a PhotoVoltaic (PV) input and battery storage to curtail grid energy usage when the price …
Incorporating Environmental And Social Factors Into Decision-Making Of An Oil And Gas Industry To Improve Sustainability, Gaurav Dabhadkar
Incorporating Environmental And Social Factors Into Decision-Making Of An Oil And Gas Industry To Improve Sustainability, Gaurav Dabhadkar
Graduate Theses and Dissertations
The energy industry (including the oil and gas industry) is facing unparalleled scrutiny and demands from stakeholders including investors, regulators (industry and environmental), communities, and other stakeholders. Sustainable development is one of the major concerns of the oil and gas industry. Companies are seeking to increase sustainability of their operations by considering environmental and Social concerns in addition to economic concerns. Oil and gas companies need to take decisions at different stages of the product life cycle (e.g. planning, design, exploration, production, and clean-up) which have direct or indirect impact on the organization's objectives. Addressing economic, technical, Social, and environmental …