Engineering Commons^™

Model Of A Photovoltaic Panel Emulator In Matlab-Simulink, Hayretti̇n Can

Turkish Journal of Electrical Engineering and Computer Sciences

Being able to behave electrically similar to photovoltaic (PV) panels, PV emulator systems make it possible to perform different PV system tests under various operation conditions. In this paper, a model of a PV panel emulator is presented using the Power System Blockset under MATLAB-Simulink. The simulation of the emulator system is developed for testing a controller prior to a real-time implementation. The model can handle the dependence of all of the parameters in the model with respect to solar radiation and temperature. The simulation results show that the output characteristics of the simulator have good agreement with those of …

The Modeling, Analysis And Control Of Resilient Manufacturing Enterprises, Yao Hu

Theses and Dissertations--Electrical and Computer Engineering

The resilience of manufacturing enterprises is an important research topic, since disruptions have severe effects on the normal operation of manufacturing enterprises, especially as manufacturing supply chains become global. Although many case studies have been carried out to address resilience in organizations, a systematic method to model and analyze the resilience dynamics in manufacturing enterprises is not well developed. This study is intended to conduct research on quantitative analysis and control for resilience.

After reviewing the literature addressing resilience, a modeling framework is presented to characterize the resilience of a manufacturing enterprise responding to disruptive events, which includes inventory ow …

Packet Coalescing And Server Substitution For Energy-Proportional Operation Of Network Links And Data Servers, Mehrgan Mostowfi

USF Tampa Graduate Theses and Dissertations

Electricity generation for Information and Communications Technology (ICT) contributes over 2% of the human-generated CO2 to the atmosphere. Energy costs are rapidly becoming the major operational expense for ICT and may soon dwarf capital expenses as software and hardware continue to drop in price. In this dissertation, three new approaches to achieving energy-proportional operation of network links and data servers are explored.

Ethernet is the dominant wireline communications technology for Internet connectivity. IEEE 802.3az Energy Efficient Ethernet (EEE) describes a Low Power Idle (LPI) mechanism for allowing Ethernet links to sleep. A method of coalescing packets to consolidate link idle …

Modeling And Simulation Of All-Electric Aircraft Power Generation And Actuation, David Woodburn

Electronic Theses and Dissertations

Modern aircraft, military and commercial, rely extensively on hydraulic systems. However, there is great interest in the avionics community to replace hydraulic systems with electric systems. There are physical challenges to replacing hydraulic actuators with electromechanical actuators (EMAs), especially for flight control surface actuation. These include dynamic heat generation and power management. Simulation is seen as a powerful tool in making the transition to all-electric aircraft by predicting the dynamic heat generated and the power flow in the EMA. Chapter 2 of this dissertation describes the nonlinear, lumped-element, integrated modeling of a permanent magnet (PM) motor used in an EMA. …

Modeling Of Sic Power Semiconductor Devices For Switching Converter Applications, Ruiyun Fu

Theses and Dissertations

Thanks to recent progress in SiC technology, SiC JFETs, MOSFETs and Schottky diodes are now commercially available from several manufactories such as Cree, GeneSiC and Infineon. SiC devices hold the promise of faster switching speed compared to Si devices, which can lead to superior converter performance, because the converter can operate at higher switching frequencies with acceptable switching losses, so that passive filter size is reduced. However, the ultimate achievable switching speed is determined not only by internal semiconductor device physics, but also by circuit parasitic elements. Therefore, in order to accurately predict switching losses and actual switching waveforms, including …

Distribution And Occurrence Of Escherichia Coli In Water And Sediments At Grand Glaize Beach In Lake Of The Ozarks State Park, Jordan Lee Wilson

Masters Theses

"Public swimming beaches at the Lake of the Ozarks State Park (LOSP) are popular vacationing spots for many Missourians; however, on several occasions Escherichia coli (E. coli) concentrations have exceeded standards set by the Missouri Department of Natural Resources (MDNR). Exceedances lead to beach closures which not only represent a potential public health threat but are also detrimental to the local economy and the public's perception of the lake's general water quality. In a collaborative effort between Missouri S&T, the United States Geological Survey (USGS) and the MDNR, an in-depth, two-summer study was conducted which included collection of …

Development Of An In Situ Measurement Device For Obtaining Material Thermal Properties, Mark A. Hepokoski

Dissertations, Master's Theses and Master's Reports - Open

This thesis presents a methodology for measuring thermal properties in situ, with a special focus on obtaining properties of layered stack-ups commonly used in armored vehicle components. The technique involves attaching a thermal source to the surface of a component, measuring the heat flux transferred between the source and the component, and measuring the surface temperature response. The material properties of the component can subsequently be determined from measurement of the transient heat flux and temperature response at the surface alone. Experiments involving multilayered specimens show that the surface temperature response to a sinusoidal heat flux forcing function is also …

Augmented Cognition In Human System Interaction Through Coupled Action Of Body Sensor Network And Agent Based Modeling, Siddhartha Agarwal, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

This research proposes a conceptual model to make significant progress in augmented cognition. We intend to design a generic architecture to improve the collective situational awareness (SA) of a team of soldiers on the battlefield during combat effects, and cultural communications. It also establishes a training outline for future landscapes of a similar nature by providing convincing feedback. It will serve as architecture of a model, based on the current laboratory framework. This involves data analysis of the feedback from the neurophysiological body sensors (heart rate, skin temperature, breathing rate and others) placed on a wearable immersive training vest. It …

Finite Element Study Of Transcranial Direct Current Stimulation: Customization Of Models And Montages, Dennis Q. Truong

Dissertations and Theses

Transcranial Direct Current Stimulation (tDCS) is a non-invasive neuromodulation technique that applies low amplitude current via electrodes placed on the scalp. Rather than directly eliciting a neuronal response, tDCS is believed to modulate excitability – encouraging or suppressing activity in regions of the brain depending on the polarity of stimulation. The particular application of tDCS is often determined by the electrode configuration and intensity of stimulation. MRI-derived finite element models have been developed to analyze the effect of these parameters allowing novel electrode configurations to be tested in subject specific models. By creating a subject specific model of an obese …

A New Diagnostics Tool For Water Injected Gas Turbines - Emissions Monitoring And Modeling, Mohammed Shafi Syed

LSU Doctoral Dissertations

Natural gas-fired cogeneration systems are commonly used for large-scale industrial energy production – both electricity generation and heat recovery. Industrial cogeneration currently represents about 8% of the U.S. total electricity generation capacity. Plans call for cogeneration to increase to 20% of the generation capacity by the end of 2030 [1, 2]. Industrial cogeneration systems attain both high thermal efficiency and low emissions. The attainment of low emissions from natural gas fired turbines, in particular low NOx emissions, is of considerable environmental importance especially as coal becomes a less favorable fuel source. Our current project addresses emissions and performance modeling of …

Multi-Physicochemical Modeling Of Solid Oxide Fuel Cells And Electrolyzer Cells, Yuanyuan Xie

Theses and Dissertations

Multi-physicochemical models are developed for solid oxide fuel cells and electrolysis cells. The models describe the complicated transport processes of charge (electron/ion) conservation, mass/species conservation, momentum conservation, and energy conservation. Transport processes are coherently coupled with chemical reforming processes, surface elementary reaction processes, as well as electro-oxidation processes of both hydrogen and carbon monoxide. The models are validated with experimental data and utilized for fundamental mechanism studies of SOFCs fueled with different type of fuels, such as hydrogen, hydrocarbon, e.g., methane, H2S, and their mixtures. The fundamental mechanisms associated with syngas generation using electrolysis cell are also extensively investigated using …

New Approach For Modeling Hybrid Pressure Swing Adsorption-Distillation Processes, Fan Wu

Theses and Dissertations

A new methodology for modeling hybrid pressure swing adsorption (PSA)-distillation processes has been developed. Two hybrid systems were simulated as examples. One is for ethanol dehydration, and the other is for propane/propylene separation. Firstly, a distillation process simulator such as Chemsep was used to simulate the distillation process of the hybrid system, in which the PSA unit was treated as a "black box" with an assumed process performance. In this way, a hybrid PSA-distillation process can be analyzed simply by performing mass balances around these units and running Chemsep to determine the possibility of energy saving compared to a reference …

Foster Impedance Data Modeling Via Singly Terminated Lc Ladder Networks, Meti̇n Şengül

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, a lossless model is developed for the given Foster impedance data. In the model, a 2-port short- or open-terminated LC ladder is used. After applying the proposed algorithm, a realizable driving-point reactance function that fits the given data is obtained. Next, this function is synthesized, resulting in the desired model. In the algorithm, there is no need to select a circuit topology for the model. Two examples are given to illustrate the utilization of the proposed modeling algorithm.

Simulation Of A Large Electric Distribution System Having Intensive Harmonics In The Industrial Zone Of Konya, Hasan Eroğlu, Musa Aydin

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, measurements were taken at different points of a sample distribution system in order to analyze the levels of harmonics that appear as a day-to-day increasing problem in electrical distribution systems. According to the measurement values, the dominant harmonics have been determined and an electrical model of the system has been prepared using the SimPowerSystems toolbox from MATLAB and Simulink. The accuracy of the electrical model has been verified by the measurement and simulation values. In addition, the transformer connection types' and impedances' simulations have been presented to understand and solve the harmonic problems in electrical distribution systems. …

Development Of Catalytic Technology For Producing Sustainable Energy, Syed Ali Z Gardezi

USF Tampa Graduate Theses and Dissertations

This dissertation explores catalyst technology for the production of renewable liquid fuels via thermo-chemical conversion of biomass derived syngas. Fischer-Tropsch synthesis is a process for converting syngas, i.e. a mixture of CO and H2, into energy rich long chain hydrocarbons and oxygenated compounds. This synthesis process involves a number of elementary reactions leading to an array of polymeric products. The economic operation of an FTS process lie in the interplay of both catalyst and reactor design. In relation to catalysis, the nature of chemisorbed species, and the fractional availability of active metal sites determines rate, conversion and yield. Similarly, reactor …

Effect Of Cement Chemistry And Properties On Activation Energy, Andre J. Bien-Aime

USF Tampa Graduate Theses and Dissertations

The objective of this work is to examine the effect of cement chemistry and physical properties on activation energy. Research efforts indicated that time dependent concrete properties such as strength, heat evolution, and thermal cracking are predictable through the concept of activation energy. Equivalent age concept, which uses the activation energy is key to such predictions. Furthermore, research has shown that Portland cement concrete properties are affected by particles size distribution, Blaine fineness, mineralogy and chemical composition. In this study, four Portland cements were used to evaluate different methods of activation energy determination based on strength and heat of hydration …

Effect Of Localized Corrosion Of Steel On Chloride-Induced Concrete Cover Cracking In Reinforced Concrete Structures, Ezeddin Rafaa Busba

USF Tampa Graduate Theses and Dissertations

Abstract: Concrete cover cracking due to reinforcement corrosion is widely accepted as a limit-state indicator in defining the end of functional service life for existing reinforced concrete (RC) structures undergoing corrosion. Many of the currently available durability prediction models are incapable of providing realistic estimates of remaining service lives of RC structures beyond the corrosion initiation point. Therefore, the need to incorporate the length of the corrosion propagation stage in a comprehensive durability prediction approach has recently received much research attention. Previous research focus however was mostly limited to the case of uniformly corroding reinforcement with only few studies addressing …

Investigation Of Mercury Use, Release, Deposition, And Exposures In The Tampa Bay Area, Ryan Algernon Michael

USF Tampa Graduate Theses and Dissertations

I investigate the links between mercury use, release, deposition, and population exposure in Tampa Bay, with the focus of identifying levers for reducing population mercury exposures. To achieve this, I investigated the trends in mercury use and release by products and processes in the Tampa Bay area using a Material Flow Analysis. Analysis of USEPA National Emissions Inventory data over time (1999 - 2008) identified relevant air source emission categories, and explored and compared state and regional trends in mercury emissions. To understand source contributions to wet deposited mercury in the Tampa Bay area, I analyzed trends in mercury deposition …

Analysis Of The Enzymatic Decomposition Of Barley Starch To Simple Carbohydrates, Mark Mathiew Williams

Master's Theses

The decomposition of barley starch plays a fundamental role in the final quality of fermented beverages in the brewing industry. The process of mashing involves steeping milled barley in water to stimulate the enzymatic decomposition of starch into simple carbohydrates. The temperature of the water significantly impacts the activity of the enzymes and in turn the resulting concentrations of sugar products. A kinetic model accurately predicting the types and quantities of sugars formed as a function of mash temperature would serve as a tool to tailor sugar profiles and optimize mashing procedures for a desired product.

Sixty minutes mashes were …

Microgrids - A Review Of Modeling, Control, Protection, Simulation And Future Potential, Shyam Naren Bhaskara, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

Results of a literature survey done on microgrids from conception to installation is presented. the purpose is to evaluate the current status, major obstacles and existing research efforts directed toward establishing functional microgrids within utility systems. This review paper covers technical issues associated with frequency control and re-synchronization associated with typical distributed energy sources. Also evaluated are regulatory and policy issues associated with ownership, maintenance, availability, coordinated equipment control, obligation to provide adequate power quality, etc. associated with operating an islanded microgrid within a utility company's service territory. Actual microgrids in operation today are described. Benchmark test systems for steady …

Model Development And Application Of Molecular Simulations For The Study Of Proton Transport In Bulk Water And For The Prediction Of Dipole Moments Of Organic Compounds, Abhishek Asthana

Theses and Dissertations

The present work demonstrates the application of molecular simulations (MD) in two different areas: proton transport in bulk water and estimation of the dipole moment of polar organic compounds. In both areas, relatively few successful and robust methodologies exist. In the first part, a new polarizable water model is developed for MD simulations of the proton transport process. The model was parametrized from a combination of quantum chemical calculations and experimental water properties. The model was implemented in MD simulation studies of liquid water at room temperature, as well as with excess protons. For pure water the model gave good …

Advancing Cyberinfrastructure To Support High Resolution Water Resources Modeling (Invited), David G. Tarboton, F. L. Ogden, N. Jones, Jeffery S. Horsburgh

Civil and Environmental Engineering Faculty Publications

Addressing the problem of how the availability and quality of water resources at large scales are sensitive to climate variability, watershed alterations and management activities requires computational resources that combine data from multiple sources and support integrated modeling. Related cyberinfrastructure challenges include: 1) how can we best structure data and computer models to address this scientific problem through the use of high-performance and data-intensive computing, and 2) how can we do this in a way that discipline scientists without extensive computational and algorithmic knowledge and experience can take advantage of advances in cyberinfrastructure? This presentation will describe a new system …

Hydraulic Modeling: Pipe Network Analysis, Trevor T. Datwyler

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Water modeling is becoming an increasingly important part of hydraulic engineering. One application of hydraulic modeling is pipe network analysis. Using programmed algorithms to repeatedly solve continuity and energy equations, computer software can greatly reduce the amount of time required to analyze a closed conduit system. Such hydraulic models can become a valuable tool for cities to maintain their water systems and plan for future growth. The Utah Division of Drinking Water regulations require cities to maintain hydraulic models of their culinary water systems, and before additional connections can be made to the water system, a licensed professional engineer must …

Reverse Osmosis Desalination With Integrated Compressed Air Energy Storage: Conceptual Design And Modeling, Pooja Mahajan

All Theses

Growing fresh water needs have led to an interest in water desalination using reverse osmosis (RO) membranes. Energy consumption has a large share in the expenses incurred to drive a reverse osmosis desalination system. With depleting fossil fuel reserves, tapping renewable sources of energy is a promising alternative to meet the energy requirements. Wind power coupled to an RO desalination system is a potential means of delivering clean water using sustainable energy. This work investigates modeling of a conceptual wind-energy-driven RO desalination system that is made possible because of an air-pressure energy storage mechanism. Bench-scale experiments were performed on an …

Analysis Of Irrigation Decision Behavior And Forecasting Future Irrigation Decisions, Sanyogita Andriyas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Farmers play a pivotal role in food production. To be economically successful, farmers must make many decisions during the course of a growing season about the allocation of inputs to production. For farmers in arid regions, one of these decisions on any given day is whether to irrigate. This research is the first of its kind to investigate the probable reasons that lead a farmer to make irrigation decisions and use those reasons/factors to forecast future irrigation decisions. This study can help water managers and canal operators to estimate short-term irrigation demands, thereby gaining information that might be useful to …

Towards A Fluid Solid Interaction Model Of A Dynamic Lung, Justin C. Jacobs

Electronic Theses and Dissertations

Because the pulmonary system is a site for both environmental particulate contamination, as well as drug delivery into the body, numerous research groups have focused on precisely understanding its inner-workings. Past research has demonstrated the need to realistically model the lung walls in order to accurately capture the complex airflow profile throughout all of the branches. Since this is paramount to properly replicating particulate transport in the lung, computational fluid dynamics simulations on their own are inadequate, as they cannot account for lung wall dilation. Only by coupling the fluid and solid domains can natural lung behavior can be effectively …

Modeling Of Power Semiconductor Devices, Tanya Kirilova Gachovska

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

One of the requirements for choosing a proper power electronic device for a converter is that it must possess a low specific on-resistance. The specific on-resistance of a bipolar device is related to the base width and doping concentration of the lightly doped drift region. This means that the doping concentration and the width of the low-doped base region in a bipolar device must be carefully considered to achieve a desired avalanche breakdown voltage and on-resistance. In order to determine the technological parameters of a semiconductor device, a one dimensional analysis is used to calculate the minimum depletion layer width, …

2d Modeling Of Forcespinning™ Nanofiber Formation With Experimental Study And Validation, Simon Padron

Theses and Dissertations - UTB/UTPA

A newly developed method of producing nanofibers, called Forcespinning™, has proven to be a viable alternative to mass produce nanofibers. Forcespinning™ utilizes centrifugal forces which allow for a host of new materials to be processed into nanofibers while also providing a significant increase in yield and ease of production. To improve and enhance the Forcespinning™ production method, a 2D computational Forcespinning™ fluid dynamics model is developed. Three computer models, namely time-independent and time-dependent inviscid models and a viscous model are obtained and the influences of various parameters on Forcespinning™ fiber formation are obtained. This work also presents a detailed explanation …

Remanufacturing Cleaning Process Evaluation, Comparison And Planning, Ozan Yagar

Theses and Dissertations - UTB/UTPA

This thesis aims to combine previous research on remanufacturing cleaning processes and applications into a single decision-making tool, in the form of software, which a remanufacturer can use to find a cleaning system that matches their specific demands. This thesis will provide an in-depth review of each cleaning process, the chemicals used in those processes, and the contamination types for which they were developed. This research also provides evaluation and comparison that assists remanufacturers in designing their cleaning systems. Finally, there will be a description and demonstration of the software. The ultimate goal is to find correct cleaning process to …

Modeling Potential Hydrochemical Responses To Climate Change And Increasing Co2 At The Hubbard Brook Experimental Forest Using A Dynamic Biogeochemical Model (Pnet-Bgc), Afshin Pourmokhtaria, Charles T. Driscoll, John L. Campbell, Katharine Hayhoe

Civil and Environmental Engineering - All Scholarship

Dynamic hydrochemical models are useful tools for understanding and predicting the interactive effects of climate change, atmospheric CO2, and atmospheric deposition on the hydrology and water quality of forested watersheds. We used the biogeochemical model, PnET-BGC, to evaluate the effects of potential future changes in temperature, precipitation, solar radiation, and atmospheric CO2 on pools, concentrations, and fluxes of major elements at the Hubbard Brook Experimental Forest in New Hampshire, United States. Future climate projections used to run PnET-BGC were generated specifically for the Hubbard Brook Experimental Forest with a statistical technique that downscales climate output (e.g., air temperature, precipitation, solar …