Engineering Commons^™

Tin Nanoparticles Encapsulated In Hollow Tio2 Spheres As High Performance Anode Materials For Li-Ion Batteries, Xiang Pan

Theses and Dissertations

Tin, an anode material with a high capacity for lithium-ion batteries, has poor cyclic performance because of the high volume expansion upon lithiation. Based on a literature review of the applications of lithium-ion batteries and current research progress of the tin-based anode materials for lithium-ion batteries, we developed a method to synthesize hollow TiO2 spheres with tin nanoparticles anchored on the inner surface of the TiO2 shell. Such a unique tin/TiO2 composite alleviates the volume change of tin–based anode materials in charge-discharge processes. SnCl2·2H2O (Tin (II) chloride dihydrate) and titanium (IV) isopropoxide (TIPT) were used as the Sn source and …

Virtual Droop Control Framework And Stability Analyses For Microgrids With High Penetration Of Renewables, Ashishkumar Kanubhai Solanki

Theses and Dissertations

Microgrids can provide the most promising means of integrating large amounts of distributed sources into the power grid and can supply reliable power to critical loads. However, managing distributed sources and loads within a microgrid during island and grid-tie modes and during transitions is a challenge. Stable operation of a microgrid is a concern specifically during the starting of motor loads, switching of large loads, and in presence of high penetration of renewable resources. Hence, a generalized control framework is required to regulate microgrid voltage and frequency, maintain power quality, manage Distributed Generations (DG) and ensure microgrid stability. Several control …

Computational And Experimental Study On Innovative Horizontal-Axis Wind Turbine Blade Designs, Abdulrahman A. Alsultan

Theses and Dissertations

This study was made to explore three novel blade geometries with intent to increase power production of a horizontal axes, three blade arrangement wind turbine. This was done by designing the blades using computer aided design (CAD) modeling software, followed by a rigorous testing phase, utilizing a computational fluid dynamics software (CFD). The blades then went into a cycle of iterative design to achieve the best parameters that will positively impact the overall power generation efficiency. These steps were followed by printing the blades utilizing 3D Printing technology, testing them for the power generation, and finally, tabulating these findings to …

Sustainable Decolorization Of Reactive And Acid Dye Wastewater Using Photo-Fenton Oxidation Both With And Without Biodegradation: Laboratory And Field Studies, Marissa R. Jablonski

Theses and Dissertations

Photo-Fenton oxidation is an advanced oxidation process (AOP) used to degrade low-concentration textile dye wastewater using expensive chemicals. The technique has shown promise in laboratory-scale projects, but has not been scaled up sustainably to function for industry. Aerobic biodegradation is a common biological treatment method used in large-scale textile industrial applications that generates large amounts of hazardous biological waste. This waste is often left open to the elements and subsequently leaches into natural waterways or onto land. This is the first study of its kind to combine the two to treat cottage-scale industry-grade textile wastewater with a dye concentration of …

A New Correlation For Predicting Aeration Efficiency For Air Diffused Systems, Hasan Baker Mohammad Al Ba'ba'a

Theses and Dissertations

Aeration efficiency is defined as the ratio of the oxygen transfer to the power consumed. It provides the best evaluation of the effectiveness of any aeration system. Most recent studies in oxygenation process focused on investigating the vital parameters affecting the oxygenation process without paying attention to the power consumption. The goal of this study is to establish an empirical correlation that describes aeration efficiency behavior with different orifice diameters.

This work has two main parts: studying bubble hydrodynamics and aeration efficiency investigation. The first goal of examining bubble hydrodynamics was to calculate some necessary parameters that have a known …

Evaluation And Forecast Of Energy Consumption In Different Sectors Of The United States Using Artificial Neural Networks, Arash Kialashaki

Theses and Dissertations

The United States is a country which consumes a vast amount of energy. In order to keep the development of the United States sustainable (diverse and productive over the time) energy planning should be carried out comprehensively and precisely. This dissertation presents a specific mathematical modeling approach towards energy demand modeling of the United States and forecast future energy demand. To generate more detailed and accurate results, this dissertation investigates the energy demand of each sector separately using the analysis of trend for unique set of independent parameters which affect the energy demand in that sector.

In solving a forecast …

Molecular Dynamics (Md) Study On The Electrochemical Properties Of Electrolytes In Lithium-Ion Battery (Lib) Applications, Negin Salami

Theses and Dissertations

While the high energy density and the power along with longer cycle life and less requirements of maintenance distinguish the rechargeable lithium-ion batteries (LIBs) from other energy storage devices, development of an electrolyte of LIBs with optimized properties still constitutes a challenge towards next-generation LIB systems with robust electrochemical performance. The electrolytes serve as the medium to provide ionic conduction path between the electrodes as their basic function. Conductivity of the solutions are mainly affected by their transport properties and the electrolyte electrode/separator interfacial phenomena. Although many contributions on thermodynamic properties of the electrolytes consist of alkyl carbonates mixed with …

A Decision Support System To Analyze, Predict, And Evaluate Solar Energy System Performance: Pvsysco (Photovoltaic System Comparison), Lisa Bosman

Theses and Dissertations

In 2010, the U.S. Department of Energy announced the SunShot Initiative, which aims to reduce the total installation cost of solar technologies by 75% between 2010 and 2020. This implies that solar energy is a top priority in the U.S. and many other countries. The purpose of this dissertation research is focused on creating a model to better understand the performance and reliability of photovoltaic (PV) energy systems over time. The model will be used to analyze, predict, and evaluate the performance of PV systems, taking into consideration technological and geographical location attributes. The overall research goal is to build …

The Occurrence, Fate, Environmental Impact, And Management Implications Of Pharmaceutical And Personal Care Products In Wastewater And The Environment, Benjamin Donald Blair

Theses and Dissertations

Pharmaceuticals and personal care products (PPCPs) are a critical part of modern life. However, there is growing evidence that the levels of PPCPs detected in wastewater effluent and in the environment have the potential to cause damage to aquatic organisms. These pollutants enter the aquatic environment primarily through human use, disposal in the drain or toilet, land application of biosolids, and veterinary sources. Numerous questions remain regarding the occurrence, fate, and impacts of PPCPs in wastewater, along with limited feasible management recommendations that would adequately mitigate the risk from these pollutants. This dissertation will present three advances in the field …

Wind Turbine Controls For Farm And Offshore Operation, Zhongzhou Yang

Theses and Dissertations

Development of advanced control techniques is a critical measure for reducing the cost of energy for wind power generation, in terms of both enhancing energy capture and reducing fatigue load. There are two remarkable trends for wind energy. First, more and more large wind farms are developed in order to reduce the unit-power cost in installation, operation, maintenance and transmission. Second, offshore wind energy has received significant attention when the scarcity of land resource has appeared to be a major bottleneck for next level of wind penetration, especially for Europe and Asia. This dissertation study investigates on several wind turbine …

Sediment Microbial Fuel Cell As Sustainable Power Resource, Ananta Kothapalli

Theses and Dissertations

This research demonstrates that Ceratophyllum demersum a root less non vascular aquatic plant has negatively affected the power generation from a Sediment Microbial Fuel cell (SMFC). In SMFC the reduced organic matter in the sediment in water produces electrons, which reduces oxygen. Whereas in Plant SMFC continuous supply of organic matter to the anode is done by rhizodeposition (root exudates). Six SMFCs were run for more than 3 months to see the effect of plants, pH and temperature on power generation. Out of six only two SMFC showed stable data. The maximum power density 18 ± 1mW/m3 was generated from …

Hydrogen Generation From Magnesium Hydride By Using Organic Acid, Yen-Hsi Ho

Theses and Dissertations

In this paper, the hydrolysis of solid magnesium hydride has been studied with the high concentration of catalyst at the varying temperature. An organic acid (acetic acid, CH3COOH) has been chosen as the catalyst. The study has three objectives: first, using three different weights of MgH2 react with aqueous solution of acid for the hydrogen generation experiments. Secondly, utilizing acetic acid as the catalyst accelerates hydrogen generation. Third, emphasizing the combination of the three operating conditions (the weight of MgH2, the concentration of acetic acid, and the varying temperature) influence the amount of hydrogen generation. The experiments results show acetic …

Low Turbulence Wind Tunnel Design And Wind Turbine Wake Characterization, Andrew Welsh

Theses and Dissertations

As the prevalence of wind turbines in the energy market increases, so too does the demand for high-wind real-estate. As a result, wind turbines are placed closer together, which leads to structural challenges due to the cyclical fatigue loading from the wake of upwind turbines. Characterizing the wake behind wind turbines with respect to those downwind is especially important given the 20-year wind turbine lifetime that commercial wind turbine consumers expect. This project aimed to characterize the near wake behind a model wind turbine.

In order to accomplish this, a 12.8 meter-long and 1.22 meter-square test section low-turbulence wind tunnel …

Dc Microgrid Modeling And Energy Storage Placement To Enhance System Stability, Carl Westerby

Theses and Dissertations

The work of this thesis represents a joint venture between the University of Wisconsin-Milwaukee and the University of Wisconsin-Madison. A DC microgrid is selected for the efficiency benefits, lack of reactive power in the system, and ease of connecting to an AC grid. The system modeling relies on physical parameters and industry standard methods for the estimation of loads and lines. An example model is created for the University of Wisconsin - Milwaukee's Campus. Due to the high penetration of renewable energy sources in the example model, system stability is a concern. To help mitigate stability issues, analysis is performed …