Engineering Commons^™

Oscillation Mitigation For Sliding-Mode Observers In Sensorless Control Of Ipmsms, Yue Zhao, Wei Qiao, Long Wu

Department of Electrical and Computer Engineering: Faculty Publications

Back electromagnetic force (EMF)-based methods are commonly used for sensorless control of interior permanent magnet synchronous machines (IPMSMs) in medium and high speed range. The feature of high robustness to system structure and parameter uncertainties makes the sliding-mode observer (SMO) a promising candidate for rotor position estimation. In a practical drive system, because of physical limitations, e.g., sampling frequency and computational resource, it is challenging to obtain a perfect sinusoidal waveform for the back EMF by a SMO, especially in high speed range. As a result, the rotor position obtained from the estimated back EMF by using the traditional inverse …

An Empirical Study On Quality Management Practices, Organization Performance And Suppliers' Selection In Southern Minnesota Manufacturing Firms, Rachel Yetunde-Abiodun Awoku

All Graduate Theses, Dissertations, and Other Capstone Projects

Quality management systems (QMS) have been widely applied successfully by many manufacturing companies to improve their process, increase profits and organizational performance. The most applied of the quality programs are ISO 9001, Total Quality Management (TQM), Just-In-time (JIT), Lean Management and Six Sigma. Although past studies on quality management have identified and studied the implementation of quality management practices, there is little or no research on quality management practices and business performance in Southern Minnesota manufacturing companies. Many researchers have concluded that the implementation of quality management practices has led to significant improvements in companies' business performance while others have …

Investigation Of A Water Desalination Method Via A Humidification-Dehumidification Process Using Hvac Technology, Juan A. Cornejo

Open Access Theses & Dissertations

Potable water is becoming a scarce resource in many arid regions of the world. An experimental unit was designed and constructed to examine and characterize the production capabilities of a humidification-dehumidification (HDH) desalination process. An HDH cycle offers a viable, technologically light, alternative for producing fresh water from brackish water because the low relative humidity air is infused with water vapor through evaporation by means of conventional heating, ventilation and air conditioning (HVAC) components. The evaporation process effectively separates salts and suspended solids from the brackish feed-water. Desalinated water is subsequently recovered by extracting the water vapor from the moist …

New Mathematical And Evolutionary Optimization Methods To Achieve Fair Division In Multi-Agent Resource Allocation, Emmanuel Gurrola Molina

Open Access Theses & Dissertations

The problem of resource allocation among a group of agents naturally arises in a wide range of real-life events. The subject has earned popularity across the disciplines of Economics, Computer Science, Artificial Intelligence Operations Research and Social Welfare. This resource allocation problem can be commonly referred to as Multi-Agent Resource Allocation (MARA). This work considers a MARA problem where a central agent decides to allocate a set of divisible and non-divisible goods. MARA is considered to be part of an interdisciplinary research area in which the literature is vast and rapidly developing. However, most of the available literature mainly focuses …

Designing Optimal Aviation Baggage Screening Strategies Using The Monkey Search Algorithm, Edgar Ivan Jimenez

Open Access Theses & Dissertations

This thesis addresses the aviation baggage screening design problem considering several baggage screening devices which may be used for system implementation, the devices have different false clear and false alarm rates, throughput and purchase costs. In the present research, a comprehensive cost function which not only includes the cost associated with purchase and operation of baggage security devices, but also includes the indirect costs associated with device errors is used. A new monkey search based evolutionary algorithm is presented to determine the best selection of baggage screening security devices in order to minimize the expected annual total cost. The final …

High Pressure Synchrotron X-Ray Diffraction Studies Of Superprotonic Transitions In Phosphate Based Solid Acids, Juan Daniel Hermosillo

Open Access Theses & Dissertations

Certain phosphate based solid acids, such as CsH2PO4 and RbH2PO4, have been shown to exhibit an abrupt, several-order-of-magnitude increase in their proton conductivity when heated above a temperature threshold. This so called superprotonic behavior allows the above-mentioned materials to function as fuel cell electrolytes at temperatures between 150C and 300C, a remarkable application that attracted significant interest especially from the automobile industry. Yet, the microscopic structures and dynamic mechanisms responsible for this behavior are not fully understood. In fact, until very recently, the very nature of the superprotonic behavior has been debate, with some groups attributing the steep proton enhancement …

Magnetic Cell Separation By Inkjet Printing For Disease Monitoring, Sylvia Lucia Natividad

Open Access Theses & Dissertations

The standard analysis technique for cell sorting, flow cytometry, requires centralized facilities such as tertiary Medical Centers. According to the U.S. Department of Health and Human Services Designated Health Professional Shortage Areas (HPSA) Statistics, in this country alone, more than 35 million people live in medically underserved areas, many of which need access to diagnostic procedures for proper management of their diseases. A cell sorting technique that can be done in low-resource settings at a decreased cost to the medical organization and the patient has been developed through this research project. By combining inkjet printing technology and magnetic labeling of …

Investigation Of The Divcon Neuron To Increase The Performance Of A Traditional Feed Forward Multi-Layer Perceptron And Its Hardware Implementation, Jovan Saenz

Open Access Theses & Dissertations

ABSTRACT

Artificial Neural Networks (ANNs) have been developed in an attempt to emulate the information processing capabilities of the biological brain. They offer an alternate computing approach to problems in which mathematical modeling is complicated, such as pattern recognition and pattern classification.

Since ANNs were proposed in the early 1940s, there has been a great amount of research effort dedicated to the development of new models that improve performance. Consequently, different architectures, a variety of activation functions, and distinct learning algorithms have been developed and implemented in different disciplines such as medicine, engineering, and science. In addition, ANNs have been …

Spatially Adaptive Interpolation And Super-Resolution Using The Optimal Recovery Framework, Abdul Jabeer Shaik

Open Access Theses & Dissertations

Reconstruction of missing pixels from the available Low Resolution (LR) Image pixels in order to create a High Resolution (HR) Image is a very important problem with many applications. In our research, we propose a spatially adaptive optimal recovery interpolation method for generating a discrete High Resolution Image from any given discrete Low resolution Image. This Spatially Adaptive OR approach is then extended to Super-Resolution technique.

Optimal Recovery (OR) method can be used for reconstructing signals from uniform samples. The OR framework uses the values of a given linear operator to estimate the value of a desired linear operator. The …

Multi-Physics Modeling Of Induction-Based Additive Manufacturing Of Metals, Danny W. Muse

Open Access Theses & Dissertations

The shift towards 3D printing of functional products has provided a glimpse of the future in terms of manufacturing technologies and the creation of volumetrically complex structures made possible only through these technologies. 3D printing has emerged from the culmination of several technologies covering multiple industries and a myriad of materials. Unlike subtractive technologies such as mills, lathes and CNC machines, where material is removed from a bulk slab or billet to produce a desired part, 3D printing uses an additive layered approach to deposit material based on cross sections of the desired part. Both approaches produce parts based on …

An Experimental Investigation On Lox/Lch4 Reaction Control Thrusters, Arturo Acosta-Zamora

Open Access Theses & Dissertations

This work describes the development and preliminary testing of a thrust measurement system, in combination with a propellant feed and automation controls systems to test the performance of 8.9 to 35.6 N (2 to 8 lbf) LOX/Methane reaction control thrusters. LOX/LCH4 has come to be the main focus of next generation "green" propellants for future space exploration. As there is limited experience with this propellant combination, an effort is being conducted to research performance of rockets using these propellants. The development of a thrust measurement, propellant feed, and automation controls systems is necessary for proper testing and qualification of thruster …

Bod5 And Cod Data Analysis From The Northwest And Robert R. Bustamante Wastewater Treatment, Juan Carlos Adame

Open Access Theses & Dissertations

The objectives of this thesis are to explore the use of basic Statistical Process Control in a Wastewater Treatment Plant with secondary treatment. Additionally, to describe statistical behavior and review normality of some reportable parameters, also to analyze mainly parameters like BOD5 (Biological Oxygen Demand), Electrical Conductivity, and COD (Chemical Oxygen Demand) with seasons of the year and days of the week, using data from the Northwest (NW) and Robert R. Bustamante (RRB) Wastewater Treatment Plants from El Paso Texas.

The scope of this analysis is to understand how Statistical Process Control can help to predict peak and valleys of …

Combustion And Compaction Of Lunar Regolith/Magnesium Mixtures, Armando Delgado

Open Access Theses & Dissertations

Feasible techniques that require low energy consumption and reduced costs are of vital importance to enable humans to explore and occupy space. In-Situ Resource Utilization (ISRU) is the branch in the Human Exploration Technology that studies the production of consumables and materials using indigenous lunar and planetary resources. ISRU represents an enabling opportunity for establishing long lasting human exploration missions. Construction materials produced in-situ are of special interest because of the high payload they represent when launching them from Earth. The in-situ production of construction materials that requires low energy input would be advantageous due to the limited energy in …

On The Extraction Of Volatiles From Lunar Regolith Using Solar Power, Jorge Alberto Frias

Open Access Theses & Dissertations

Recent lunar missions have confirmed the presence of water and miscellaneous volatiles within the craters of the Moon's South Pole. If harvested, these resources have the potential to provide an incredible budget saving to the human space exploration program by dropping the total mass that astronauts need to carry from the Earth. The area that develops these technologies is called In-Situ Resource Utilization (ISRU). ISRU allows reducing the payload, and consequently reduces the energy consumption and cost of space exploration. The present thesis investigates methods for the extraction of volatiles from regolith within the shadowed craters of the Moon using …

Modeling Large-Truck Involved Crashes: An Econometric Modeling Framework, Mouyid Islam

Open Access Theses & Dissertations

This research aims to analyze large-truck involved crashes (i.e., having a gross vehicle weight rating more than 10,000 pounds) through the application of advanced econometric modeling techniques--namely, random parameter models (i.e., tobit regression, mixed logit). To achieve this, various national and state specific data sets are analyzed with the goal to provide an improved understanding of the complex interactions of contributing factors (e.g., factors related to drivers and occupants, vehicle, and road-environment) influencing large-truck crashes. Additionally, the modeling techniques considered in this research account for possible unobserved effects related to the data. The aforementioned econometric techniques provide an analytical foundation …

Reverse Osmosis Permeate Post-Treatment By Upflow Calcite Contactors: Dissolution And Mass Transport, Luis Demetrio Maldonado-Castaneda

Open Access Theses & Dissertations

Reverse osmosis (RO) desalination may be used for desalination of brackish and saline waters, but the product water may have low concentrations of hardness and alkalinity, which may corrode infrastructure. Adjustment of pH and addition hardness and alkalinity may be required to meet potable water guidelines. Upflow calcite contactors may be used instead of lime or caustic addition for post-treatment of RO permeate to deliver non-blended, stable, non-corrosive finished water.

The first objective of this research was to experimentally determine the sensitivity of performance of upflow calcite contactors with respect to several design and operational parameters such as: feed pH, …

Sustainable Water Management In The University Of Texas At El Paso, Cora Martinez

Open Access Theses & Dissertations

This thesis showed how to improve water and financial savings for UTEP and El Paso by improving water conservation and sustainability of the UTEP campus. The goals of this research were successfully accomplished by focusing in three principal objectives.

1. Analyze historical data of water consumption of the UTEP campus for the past decade.

2. Evaluate water consumption to quantify water consumption by buildings and type of use, as well as provide recommendations for water and cost savings.

3. Synthesize a water management framework within the UTEP Facilities' Geographic Information System (GIS) for long-term monitoring and evaluation

Development Of Advanced Polymer Nanocomposite Capacitors, Miguel Mendoza

Open Access Theses & Dissertations

The current development of modern electronics has driven the need for new series of energy storage devices with higher energy density and faster charge/discharge rate. Batteries and capacitors are two of the most widely used energy storage devices. Compared with batteries, capacitors have higher power density and significant higher charge/discharge rate. Therefore, high energy density capacitors play a significant role in modern electronic devices, power applications, space flight technologies, hybrid electric vehicles, portable defibrillators, and pulse power applications. Dielectric film capacitors represent an exceptional alternative for developing high energy density capacitors due to their high dielectric constants, outstanding breakdown voltages, …

Hafnia-Based Nanostructured Thermal Barrier Coatings For Next Generation Gas Turbine Technology, Mohammed Noor-A-Alam

Open Access Theses & Dissertations

Extensive efforts have been directed in the last several decades towards improving thermodynamic efficiency of industrial gas turbines for power generation plants. The central theme of the efforts is to increase the turbine operating temperature and, thus, allowing higher efficiency. Thermal barrier coatings (TBC) constitute an advanced technology to protect the metallic surface from high temperature exposure for long time operation. The TBCs protect the gas turbine components from high temperature and allows further increase in engine operating temperature which subsequently increases the efficiency of the gas turbine power plant. However, the current TBC materials are capable of allowing the …

Evaluation Of Ozone Trends And Distribution In The Paso Del Norte Region Using Tceq's Cams Data And Ozone Data Collected At Two Supplemental Sites, Adrian Michael Sandoval

Open Access Theses & Dissertations

The purpose of this research was to determine whether the city of El Paso will continue to be in attainment if the Environmental Protection Agency (EPA) revises the National Ambient Air Quality Standards (NAAQS) of 8-hour average ozone concentration from 0.075 parts per million (ppm) to 0.070 ppm. For the duration of El Paso's ozone season, June-September 2012, two 2B Technology Ozone 202 monitors were deployed at proposed locations, not previously monitored. This was done in order to quantify concentration of ozone. In addition, ozone and meteorological data was downloaded from several Continuous Ambient Monitoring Stations (CAMS) in the Paso …

Numerical Analysis Of Single Tank Thermocline Thermal Storage System For Concentrated Solar Power Plant, Samia Afrin

Open Access Theses & Dissertations

The overall efficiency of a Concentrating Solar Power (CSP) plant depends on the effectiveness of Thermal Energy Storage (TES) system. A Single tank TES system has potential to provide effective solution. In a single tank TES system, a thermocline region, which produces the temperature gradient between hot and cold storage fluid by density difference, is used. Preservation of this thermocline region in the tank during charging and discharging cycles depends on the uniformity of the velocity profile at any horizontal plane. One of the major challenges for the single tank thermocline is actually maintaining the thermocline region in the tank, …

Applications Of Density Functional Theory In Materials Science And Engineering, Manuel Alvarado

Open Access Theses & Dissertations

Density Functional Theory (DFT) is a powerful tool that can be used to model various systems in materials science. Our research applies DFT to two problems of interest. First, an organic/inorganic complex dye system known as a Mayan pigment is modeled to determine chemical binding sites, verifying each model with physical data such as UV/Vis spectra. Preliminary studies on palygorskite-based mayan pigments (mayacrom blue, mayacrom purple) show excellent agreement with experimental studies when using a dimer dye geometry binding with tetrahedrally-coordinated aluminum impurity sites in palygorksite. This approach is applied to a sepiolite-based organic/inorganic dye system using thioindigo attached to …

Selection Of Sustainable Rigid Pavement Using The Mechanistic-Emperical Pavement Design Guide, Laith Ali Al Sabty

Open Access Theses & Dissertations

A new pavement design guide called "Mechanistic-Empirical Pavement Design Guide (ME-PDG)" has been developed for design and rehabilitation of pavements. The guide uses general characteristics, traffic, environmental conditions, and pavement structure information to estimate pavement life. ME-PDG is a comprehensive program which requires significant number of inputs and time to analyze and predict pavement performance.

In El Paso, Texas most of the urban highways are constructed as Continuously Reinforced Concrete Pavement (CRCP). Although commonly placed, the design life of CRCP pavements is rarely realized. In addition, the cost of constructing CRCP is significantly higher than the Jointed Plain Concrete Pavement …

Measurement And Analysis Of Turbulent Syngas/Air And Methane Oxy-Combustion, Vishwanath Reddy Ardha

Open Access Theses & Dissertations

Development of a next generation gas turbine combustors for power production by using fossil fuels is increasing substantially in order to maintain energy sustainability. National Energy Technology Laboratory has made efforts for developing hydrogen and oxy-fuel based gas turbine combustors which could enhance plant efficiency and ensure low or zero NOx production without sacrificing operational advantages. The current experimental work aims to characterize the turbulent flow-field of premixed syngas/air flames, methane/oxy flames and syngas/oxy flames in a laboratory scaled burner by varying the Reynolds numbers, blockage ratios, firing inputs and blockage ratios in the upstream of the burner. The effects …

Carrier Collaborative Networks: Hybrid Hub Location Algorithms, Satyen Suresh Awale

Open Access Theses & Dissertations

Within the context of the Logistics and supply chain and management, the Hybrid Hub and Spoke system has certain complexities regarding the selection of the hub location in the supply chain facility system. The performance and efficiency of the network route selection and hub location depends upon the percentage savings that has been made by choosing the appropriate location for the hub to maintain the efficient flow of the goods within the network. Hub location selection mostly depends on the profit margins shared by the carrier, supply and demand status of the facility and amount of flow of the goods …

Transparent And Amorphous W-Ti-O Nano-Coatings, Gaurav Baghmar

Open Access Theses & Dissertations

The present work was performed on the Ti-doping effects in a small and controlled amount into WO3 to produce W0.80Ti0.20O3. The aim of study is to explore the effect of Titanium (Ti) coupled with growth temperature on the growth of behavior, microstructure and optical properties. W0.80Ti0.20O3 coatings were fabricated using RF magnetron sputter-deposition onto Silicon (Si-100) wafers and optical quality Quartz substrates. The depositions were made in a wide temperature ranging from room temperature (25 ˚C) to 500 ˚C. X-ray diffraction (XRD), high-resolution scanning electron microscopy (SEM), Optical spectrophotometery and Spectroscopic Ellipsometry (SE) were performed to study the effect of …

Ozone Studies In The Paso Del Norte Region, Fernando Becerra-Davila

Open Access Theses & Dissertations

The Paso del Norte region forms the largest contiguous bi-national conglomerate on the US-Mexico border. With a combined population of around 2 million inhabitants, the Paso del Norte region is isolated, more than 500 km away from the nearest urban area of comparable size, thus making it an ideal location for air quality studies of an isolated urban environment.

The meteorological conditions leading to a high ozone episode in this region, such as the historical ozone episode of June 2006, are analyzed. It is well known that stagnation and minimal winds, high temperatures, and pressure ridges over the region are …

Methodologies For The Analysis Of Checked Baggage Inspection Systems, Nela Blejcharova

Open Access Theses & Dissertations

To enhance the security of the aviation system it is necessary to have a Checked Baggage Inspection System (CBIS) that is effective (that is, the highest possible detection probability or minimum false clear probability) yet efficient (that is, minimize the false alarm probability that causes inconvenience to passengers).

The first objective of this thesis is to review passenger, carry-on and checked baggage inspection procedures at airports

The second objective of this thesis is to develop a methodology using the optimization approach to set the optimal values of the sensitivity of the screening devices to minimize the total cost of inspecting …

Comparison Study Between Fem And Sem For Wave Propagation Models Applied To Solids, Shaddy Roberto Castillo Ponton

Open Access Theses & Dissertations

Wave propagation is a field whose application has spread across many disciplines. In the field of structural engineering, wave propagation methods have focused their attention specifically in the area of structural health monitoring and active control of vibrations and noise. Likewise, the development of new methods and their application have been successful in the area of material science with a special emphasis on the field of structural integrity evaluation of anisotropic and inhomogeneous structures (laminated composite structures). The current available analysis tools are inadequate to handle the modeling of complex structures. One-dimensional wave propagation problems in solids are still a …

Vulnerability Of Intermodal Logistic Networks To Sea Port Disruption, Jana Cervinska

Open Access Theses & Dissertations

Maritime trade is the backbone of international trade, specifically seaports which provide the gateway for the shipping and receiving of all international goods. Any disruption in operation can trickle down the global supply chain increasing costs and delay delivery of supplies. Hence, the objective of this work is the formulation of optimization models to study the vulnerability of intercontinental ports. Experiments are applied to container transportation between U.S. and Europe. The work differentiates itself from previous studies in that we analyze the vulnerability of the sea ports and compare how the closing of some ports or liner shipping lanes influence/impact …