Power and Energy Commons^™

Capacity Optimization Of Battery-Generator Hybrid Power System: Toward Minimizing Maintenance Cost In Expeditionary Basecamp/Operational Energy Applications, Jude C. Onwuanumkpe

Open Access Theses

Low and transient load condition are known to have deleterious impact on the efficiency and health of diesel generators (DGs). Extensive operation under such loads reduces fuel consumption and energy conversion efficiency, and contribute to diesel engine degradation, damage, or catastrophic failure. Non-ideal loads are prevalent in expeditionary base camps that support contingency operations in austere environments or remote locations where grid electricity is either non-existent or inaccessible. The impact of such loads on DGs exacerbates already overburdened basecamp energy logistics requirements. There is a need, therefore, to eliminate or prevent the occurrence of non-ideal loads. Although advances in diesel …

Investigation Of The Use Of A Plasticizer-Polymer Sensor Coating With Improved Long-Term Stability In The Liquid Phase, Laura Jeanne Alderson

Master's Theses (2009 -)

Benzene is one of the volatile organic compounds present in crude oil and gasoline. Leakage from underground storage tanks or hazardous waste sites can introduce benzene contamination into nearby groundwater. Benzene is a known carcinogen and its exposure is limited by the Environmental Protection Agency to 5 parts per billion (ppb) in drinking water. Early, accurate detection of the presence of benzene contamination in groundwater supplies is extremely important. Shear horizontal surface acoustic wave (SH-SAW) devices with a chemically sensitive coating can be used for the detection of volatile organic compounds in liquid, such as BTEX (benzene, toluene, ethylbenzene and …

Thin Film Studies Toward Improving The Performance Of Accelerator Electron Sources, Md Abdullah Al Mamun

Mechanical & Aerospace Engineering Theses & Dissertations

Future electron accelerators require DC high voltage photoguns to operate beyond the present state of the art to conduct new experiments that require ultra-bright electron beams with high average current and higher bunch charge. To meet these demands, the accelerators must demonstrate improvements in a number of photogun areas including vacuum, field emission elimination in high voltage electrodes, and photocathodes. This dissertation illustrates how these improvements can be achieved by the application of suitable thin-films to the photogun structure for producing ultra-bright electron beams.

This work is composed of three complementary studies. First, the outgassing rates of three nominally identical …

Electrochemical Detection Of Hydrogen Peroxide At Aunps Modified Electrode Using P-Hydroxyphenylboronic Acid As A Precursor, Chun-Yan Wang, Xiao-Qiu Liu, Ying-Xin Qi

Journal of Electrochemistry

We developed a new method for electrochemical detection of hydrogen peroxide (H₂O₂) based on boronate oxidation of p-hydroxyphenylboronic acid. This method using p-aminophenol which is produced from the reaction of H₂O₂ and p-aminophenylboronic acid as a well electrochemical probe, combined with a gold nanoparticles (AuNPs) modified electrode for an indirect detection of H₂O₂. Because of the large surface area and enhanced electrocatalytic behavior by the AuNPs modified electrode, the detection sensitivity was improved. The method could detect H₂O₂ in the concentration range of 1 ~ 100 …

Electrochemical Determination Of Hg(Ii) At Gold Nanoparticles@Carbonaceous Microspheres Modified Electrode, Tian-Yu Qiu, Ming-Chun Wang, Xian-Feng Du, Tian-Jia Jiang, Xing-Jiu Huang

Journal of Electrochemistry

The gold nanoparticles@carbonaceous microspheres (Au@CMSs) and  Au@CMSs modified glassy carbon electrode (GCE) were prepared. The Au@CMSs modified  GCE was further examined for possible sensitive detection of mercury ions (Hg(II)) in an aqueous solution by square wave anodic stripping voltammetry (SWASV). The excellent performance was found in the stripping analysis of Hg(II) in 0.1 mol•L^-1 NaAc-HAc(pH=5.0) with a sensitivity of 25.863 A•(mol•L^-1)^-1 and a detection limit of 3.69×10^-8 mol•L^-1 based on the 3σ method.

Fabrication Of Riboflavin Electrochemical Sensor Based On Au Nanoparticles/Polydopamine/Carbon Nanotubes Modified Glassy Carbon Electrode, Hua-Ping Peng, Mei-Ling Yu, Xin Liu, Pan Liu, Wei Chen, Ai-Lin Liu, Xin-Hua Lin

Journal of Electrochemistry

A novel electrochemical platform for the high sensitivity detection of riboflavin was constructed by Au nanoparticles/polydopamine/carbon nanotubes (Au-PDA-MWCNTs) nanocomposite modified glassy carbon electrode. The Au-PDA-MWCNTs nanocomposite was synthesized by in situ reduction method. The characteristics of the as-prepared Au-PDA-MWCNTs nanocomposite modified electrodes were investigated by using UV-Vis spectroscopy, scanning electron microscopy (SEM) and electrochemical methods. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to study the electrochemical behavior of riboflavin (RF) at Au-PDA-MWCNTs nanocomposite modified electrodes. The results demonstrated that the present electrochemical sensor exhibited a wide linear range from 5×10^-9 mol•L^-1to 1×10^-5 mol•L …

Synthesis Of Fe, N-Doped Graphene/Carbon Black Composite With High Catalytic Activity For Oxygen Reduction Reaction, Chi Chen, Zhi-You Zhou, Xin-Sheng Zhang, Shi-Gang Sun

Journal of Electrochemistry

Oxygen reduction reaction (ORR) is a bottleneck for improving the efficiency of proton-exchange membrane fuel cells as a cathode reaction due to its sluggish kinetics. The exploitation of low cost and high performance non-precious metal catalysts such as Fe/N/C based materials toward ORR has attracted extensive attentions. In this work, the Fe, N-doped graphene nanosheets/carbon black composite was prepared by hydrothermal polymerization and followed by a twice-heat-treatment procedure using 2-aminoimidazole as an N precursor, FeCl₃ as an Fe precursor and KJ600 carbon black as a support. The TEM images revealed that the graphene nanosheets were separated by carbon black …

Electrochemical Syntheses Of Graphene And Its Composites, Bo Zhao, Li Jiang, Ming-Hui Yuen, Xian-Zhu Fu, Rong Sun, Ching-Ping Wong

Journal of Electrochemistry

Graphene is a kind of ideal two-dimensional flat carbon nanomaterials which have unique chemical and physical properties. The attractive potential applications must be based on the high quality mass production of graphene. However, it remains a huge challenge. An electrochemical approach is a fast, environmental friendly and easy-operating method. single- or multi-layered graphene flakes can easily be produced in short periods of time. In this review, the structure, properties and preparation methods of graphene are first introduced. Accordingly, the electrochemical approaches used for the productions of graphene flakes, graphene/inorganic nanocomposites, graphene/polymer composites and graphene analogues are highlighted. Finally, challenges and …

Temperature Effects On Properties Of Aerospace Nickel Hydrogen Cells, Hai-Chang Zhang, Yu-Qi Diao, Wen-Cheng Ming, Xue-Ying Ren, Fei Ding

Journal of Electrochemistry

This has been done using the 60 Ah nickel-hydrogen cell to investigate the temperature effects on properties of aerospace nickel hydrogen cells. The charge-discharge, trickle charge, overcharge, self-discharge and cycle life tests were carried out at different temperatures. The results show that the discharge capacity and overcharge rate were increased first, and then decreased with the raising temperature. On the other hand, the trickle charge value and the 3 days self-discharge rate were raised with increasing temperature. When the temperature was -5 ^oC, the discharge capacity of cell reached the maximum discharge capacity of 63.68 Ah. Based on the …

Effect Of Flame Retardant On Electrochemical Performances Of Lithium Ion Battery With Lini0.4Co0.2Mn0.4O2 As A Positive Electrode Material, Yan-Zhuo Lv, Yong-Xian Ge, Zhen-Bo Wang, Ke Ke

Journal of Electrochemistry

The effect of flame retardant on the electrochemical performances of lithium ion battery by using LiNi_0.4Co_0.2Mn_0.4O₂ as a positive material was studied by measuring the first charge-discharge, cycling, circulation, and AC impedance curves. The experimental data indicated that the discharge capacity of the battery decreased, while the charge transfer resistance and the lithium ion diffusion resistance increased with the increases in the concentrations of the flame retardant in the electrolyte solutions. Furthermore, the stability of the battery at small discharge ratios and the cyclic performance were also improved by the addition of flame …

Electricity Generation Of Microbial Fuel Cell Using Stainless Steel Mesh As Cathode, Hong-Yan Dai, Hui-Min Yang, Xian Liu, Xuan Jian, Xiu-Li Song, Zhen-Hai Liang

Journal of Electrochemistry

In the present work, a dual-chamber microbial fuel cell (MFC) was constructed with aeration tank sludge as an inoculum, carbon felt as an anode and stainless steel mesh without any modification as a cathode. The influence of the cathode size was investigated in terms of voltage output, power generation and electrochemical impedance. The long-term durability of the stainless steel mesh cathode was also evaluated. Results showed that the stainless steel mesh exhibited satisfactory long-term durability as MFC cathode. When the stainless steel mesh size was 2 × 2 cm², the maximum output voltage, power density, the internal resistance …

The Study On Comparison Of Electrochemical Performance In Microbial Fuel Cell With Glucose And Sodium Acetate Acting As Substrates, Lei Fan, Yu Zhao, Ting Li, Qin-Bo Yuan, En-Zhi Wang, Xiao-Bin Wang, Jun-Wen Wang

Journal of Electrochemistry

By inoculating aerobic sludge and anaerobic sludge from the sewage treatment plant, two sets of dual-chamber microbial fuel cells (MFCs) were built with either glucose or sodium acetate acting as a substrate. Accordingly, the electrochemical performances of MFCs were explored with the concentration of the substrates being 0.0335 mol⋅L^-1. The results of the comparative study in glucose system and sodium acetate system showed that the impedance values of anodic half cell were 222 Ω for glucose and 213.67 Ω for sodium acetate, implying no significant effect on the internal resistance in battery with the different substrates. The exchange …

State-Of-The-Art Review Of Cathodic Protection For Reinforced Concrete Structures, Aimee Byrne, Niall Holmes, Brian Norton

Articles

Cathodic protection (CP) limits the corrosion of a metal surface by making it the cathode of an electrochemical cell. This can be achieved either by using a more active sacrificial anode to create a driving current, or by using inert anodes and impressing a current onto the cathode surface using an external direct current (DC) source. Impressed current cathodic protection (ICCP) is preferred where widespread protection is required, particularly in reinforced concrete structures. ICCP needs a constant DC power supply that is usually provided through a grid connection or independent generators. This paper presents the currently available CP systems for …

Use Of Forecast Uncertainties In The Power Sector: State-Of-The-Art Of Business Practices, Corinna Möhrlen, Ricardo J. Bessa, Morgane Barthod, Gianni Goretti, Malte Siefert

Conference papers

The work we present is an investigation on the state-of-the-art use of forecast uncertainties in the business practices of actors in the power systems sector that is part of the “IEA Wind Task 36: Wind Power Forecasting”. The purpose of this task is to get an overview of the current use and application of probabilistic forecasts by actors in the power industry and investigate how they estimate and deal with uncertainties. The authors with expertise in probabilistic forecasting have been gathering information from the industry in order to identify the areas, where progress is needed and where it is difficult …

Ingan Leds For General Lighting: Overcoming Efficiency Droop At High Current Injection, Nicolas Andrade

AUCTUS: The Journal of Undergraduate Research and Creative Scholarship

According to the Energy Information Administration's Annual Energy Outlook report in 2011, the United States alone consumed 97.8 quadrillion Btus (quads) of primary energy in 2010. Roughly 41% of this energy was consumed for electricity use, with 18% of the electricity being dedicated to lighting. The International Energy Agency (IEA) estimated light consumption of this scale translates to CO2 production equivalent to 70% of the emissions from all of the world's light passenger vehicles. Pollution levels at this rate caused 18,200 premature deaths, 2,100,000 days of medication, and 29 million cases of lower respiratory symptoms.

Economic Analysis Of A Data Center Virtual Power Plant Participating In Demand Response, Labi Bajracharya

Electronic Theses and Dissertations

Data centers consume a significant amount of energy from the grid, and the number of data centers are increasing at a high rate. As the amount of demand on the transmission system increases, network congestion reduces the economic efficiency of the grid and begins to risk failure. Data centers have underutilized energy resources, such as backup generators and battery storage, which can be used for demand response (DR) to benefit both the electric power system and the data center. Therefore, data center energy resources, including renewable energy, are aggregated and controlled using an energy management system (EMS) to operate as …

The Impact Of Different Battery Technologies For Remote Microgrids, Ali Barjs Allruwaili

Electronic Theses and Dissertations

Energy storage systems are considered an effective solution for remote microgrids. They allow to increase the overall system reliability, performance, and reduce operational cost by increasing the energy utilization of renewable energy resources (PV and wind energy). A battery can reduce the system's operational cost by matching a diesel generator with the load demand. There are many types of batteries which can be used in remote microgrids, such as Lead-acid, Lithium-ion, Zinc-bromine and Aqueous Hybrid Ion. By selecting a battery which provides low operational cost and longer battery life is complex, relying on many key technical features which affect the …

Lead Free Ch3nh3sni3 Perovskite Thin-Film With P-Type Semiconducting Nature And Metal-Like Conductivity, Anastasiia Iefanova

Electronic Theses and Dissertations

CH3NH3SnI3 and CH3NH3PbI3 have become very promising light absorbing materials for photovoltaic devices over the last several years. CH3NH3PbI3 based perovskite solar cells have reached a solar-to-electricity conversion efficiency of ~ 22%. Nevertheless, CH3NH3PbI3 perovskite solar cells contain lead, which has serious consequences for the environment and human health. In this work, the lead was replaced with less toxic tin. Lead free CH3NH3SnI3 perovskite thin film was prepared by two low temperature solution processing methods and characterized using various tools such as Xray Diffraction (XRD) and absorption spectroscopy (UV-VIS). The distinctive p-type semiconducting nature and metal like conductivity of CH3NH3SnI3 …

Efficiency And Reliability Analysis Of Ac And 380v Dc Data Centers, Bijen Raj Shrestha

Electronic Theses and Dissertations

The rapid growth of the Internet has resulted in colossal increase in the number of data centers. A data center consume a tremendous amount of electricity resulting in high operation cost. Even a slight improvement in the power distribution system of a data center could save millions of dollars in electricity bills. Benchmarks for both AC and 380V DC data centers are developed and efficiency analyses thereof have been performed for an entire year. The efficiency of the power distribution system can be increased if number of power conversion stages can be reduced and more efficient converters are used. Use …

Frequency Control Of Wind And Pv Based Isolated Microgrid, Lekhnath Kafle

Electronic Theses and Dissertations

The wind and solar PV based isolated microgrid can be economical and reliable for the remote area where the grid is not available. The frequency and voltage fluctuation are major problems in such remote microgrid due to intermittent nature of renewable resources like wind and solar PV. The frequency fluctuation should remain within acceptable limits for stable operation of the remote microgrid. This thesis work focuses on frequency control of wind and photovoltaic (PV) based isolated micro-grid using traditional droop control technique. The battery system acts as a master unit which is responsible for setting up the common AC bus …

Implementation Of Solar Irradiance Forecasting Using Markov Switching Model And Energy Management System, Ayush Shakya

Electronic Theses and Dissertations

Photovoltaic (PV) systems integration is increasingly being used to reduce fuel consumption in diesel-based remote microgrids. However, uncertainty and low correlation of PV power availability with load reduce the benefits of PV integration. These challenges can be handled by introducing reserve, which however leads to increased operational cost. Solar irradiance forecasting helps to reduce reserve requirement, thereby improving the utilization of PV energy. In this thesis, a new solar irradiance forecasting method for remote microgrids based on the Markov Switching Model (MSM) is presented. This method uses locally available data to predict one-day-ahead solar irradiance for scheduling energy resources in …

Composite Gel Polymer Electrolyte For Lithium Ion Batteries, Roya Naderi

Electronic Theses and Dissertations

Batteries have been ubiquitously utilized in enormous applications such as portable electronics, satellites, computers, medical instruments, and electric cars. The development of battery technology has been through a long journey since the 17th century, paving its way to commercialization of lithium ion batteries in 1991 by Sony. Rechargeable lithium ion batteries represent the most favorable type of batteries for portable applications due to their high energy density compared to other alkali metals. In 1997, lithium polymer batteries with solid polymer/composite electrolyte were introduced where the safety drawbacks of the liquid electrolyte were eliminated but the ionic conductivity of the batteries …

Study Of Moisture And Water Effects In Low Temperature Crystallization Of Perovskite Film For Efficient Solar Cells, Ashish Dubey

Electronic Theses and Dissertations

Organic-inorganic perovskite solar cells have become a promising alternative to fossil fuel based energy sources due to their unique properties such as tunable low bandgap, long charge diffusion length, low exciton binding energy and balanced charge transport. The semiconducting perovskite films are typically prepared from low temperature solution processing and the corresponding solar cells have exhibited power conversion efficiency (PCE) of more than 20%. However, perovskite solar cells suffer from poor stability in presence of moisture and use of toxic element (Pb). Understanding the crystallization process and the effects of moisture and water is important to obtain high quality perovskite …

Battery Energy Storage System (Bess) Based Photovoltaic Charging Station (Pv-Cs) For A Green University Transportation, Ayda Esfandyari, Agata Świerc, Brian Norton, Michael Conlon, Sarah Mccormack

Conference Papers

With the trends encouraged by governments and political parties to increase the adoption of Renewable Energy Sources (RES); solar energy, and in particular photovoltaics (PV), is poised as an excellent candidate to offset the energy requirements of charging stations (PV-CS) for Electric Vehicles (BEV). This work presents a 10.5 kW Transient System Simulation (TRNSYS) model of a university campus PV-CS to determine sizing as well to determine the best operating strategies for a Battery Energy Storage System (BESS). The economical optimization model is formulated via theoretical approach adopting the Simple Payback Period (SPP) indicator. The optimization takes into account the …

Solid-State Transformers For Interfacing Solar Panels To The Power Grid: An Optimum Design Methodology Of A High Frequency Transformer For Dc-Dc Converter Applications, Kenny George

Inquiry: The University of Arkansas Undergraduate Research Journal

Nowadays the use of power electronic interfaces to integrate distributed generation with the power grid is becoming relevant due to the increased penetration of renewable energy sources like solar, and the continued interest to move to a smarter and more robust electric grid. Those interfaces, which also provide a voltage step-up or step-down function, are of particular interest because renewable energy sources do not always have voltages compatible with the connecting grid. Among them, the so-called “power electronic transformer” or “solid-state transformer” (SST) is the focus of significant research. Advantages such as bidirectional power flow, improved system control, reduced size, …

Supervision Of Community Based Microgrids: An Economic Model Predictive Control Approach, Francesco Tedesco, Lubna Mariam, Malabika Basu, Alessandro Casavola, Michael F. Conlon

Conference papers

Abstract— In this paper, an Economic Model Predictive Control (EMPC) approach has been presented to manage a Community-based microgrid (C-µGCC) at the pricing level. The main task is at satisfying the demand at prosumer sides and, at the same time, optimizing various µ-Grid contrasting objectives. Emphasis has been given to the operational constraints related to the components lifetime, whose satisfaction would be beneficial for the grid in that the maintenance and replacement costs would be reduced. A simulative analysis has been carried out on the basis of available measured data related to a location in Dublin, Ireland. Results show the …

A Comparative Analysis Of Energy Balance Of Thermoelectric Power Generation Vs. Fiberglass Insulation, Irl N. Lemar

Undergraduate Honors Theses

No abstract provided.

Development Of Analytical Equations For Optimum Tilt Of Two-Axis And Single-Axis Rotating Solar Panels For Clear-Atmosphere Condition, Gaurav Subhash Gugale

Browse all Theses and Dissertations

Solar Energy is a renewable energy source which is used widely in recent times. Photovoltaic panels collect the sun’s energy and convert it to electricity. Photovoltaic panels are being widely used in both domestic applications, commercial applications, and small-scale power generation applications. Photovoltaic panels are easy to install, they generate most of their power when electrical demands peak, prices of photovoltaic panels are dropping rapidly, photovoltaic panels require low maintenance, their operating costs are minimal, and they are highly suitable for remote applications. The amount of electricity produced by photovoltaic panels depends on the amount of sunlight the panel captures. …

Predictive Control Of Power Grid-Connected Energy Systems Based On Energy And Exergy Metrics, Meysam Razmara

Dissertations, Master's Theses and Master's Reports

Building and transportation sectors account for 41% and 27% of total energy consumption in the US, respectively. Designing smart controllers for Heating, Ventilation and Air-Conditioning (HVAC) systems and Internal Combustion Engines (ICEs) can play a key role in reducing energy consumption. Exergy or availability is based on the First and Second Laws of Thermodynamics and is a more precise metric to evaluate energy systems including HVAC and ICE systems. This dissertation centers on development of exergy models and design of model-based controllers based on exergy and energy metrics for grid-connected energy systems including HVAC and ICEs.

In this PhD dissertation, …

System Frequency Support Of Permanent Magnet Synchronous Generator-Based Wind Power Plant, Ziping Wu

Electronic Theses and Dissertations

With ever-increasing penetration of wind power into modern electric grids all over the world, a trending replacement of conventional synchronous generators by large wind power plants will likely result in the poor overall frequency regulation performance. On the other hand, permanent magnet synchronous generator wind Turbine System (PMSG-WTG) with full power back to back converters tends to become one of the most promising wind turbine technologies thanks to various advantages. It possesses a significant amount of kinetic energy stored in the rotating mass of turbine blades, which can be utilized to enhance the total inertia of power system. Additionally, the …