Engineering Commons^™

Hybrid Manufacturing: Integrating Stereolithography And Direct Print Technologies, Amit Lopes

Open Access Theses & Dissertations

The focus of this research was the development of a hybrid manufacturing system that integrates stereolithography (SL) and direct print (DP) technologies to fabricate three dimensional (3D) structural electronic devices within a single set-up. The capabilities of this new additive manufacturing (AM) technology was explored in the context of fabricating and prototyping complex electronic devices in which conformal shape, rugged and light-weight integration, and a natural resistance to reverse engineering are all of paramount importance. Consequently, electronic components can be tightly integrated together in a rugged, light-weight 3D structure of arbitrary form. This research is a continuing advancement of the …

Renewable Energy Integration: An Approach For Micro-Grid Optimization., Nicolas Lopez

Open Access Theses & Dissertations

This thesis explores the Renewable Energy Integration Problem beginning with a literature review on the different sources of electrical energy classified as Non-Renewable and Renewable, stating that the integration of renewable sources within the pre-existing Power-Grids is a current worldwide problem that is being addressed with different approaches.

The impossibility to exactly model the different equations relating the electric output of the renewable energy sources as they relate with meteorological factors, makes the renewable sector a stochastic component of the overall mathematical model, where it can be concluded that most of the problem is in the area of the forecast. …

Computational Study Of Fluid-Valve Interaction Involving Deep Vein Thrombosis, Upendra Parimi

Open Access Theses & Dissertations

The venous valves in veins carry on the important function of eliminating the retrograde (re-verse) flow of blood in veins and help the veins to carry on their work effectively. The abnormal functioning of venous valves can cause deep vein thrombosis (DVT) which is a phenomena caused by clotting in deep veins. The importance of the thesis work lies in understanding the role of blood flow dynamics in Deep Vein Thrombosis (DVT). Elderly People and pregnant women are the ones who are most likely to develop DVT. It was determined from previous studies that women in their postpartum period are …

Health Prognisis Of Electronics Via Power Profiling, Jonathan Amilcar Cervantes

Open Access Theses & Dissertations

The objective of this research is to investigate a new approach for the early detection of latent defects in electronic devices in the field. Reliability is assessed through the non-traditional approach of recording and evaluating the power profile of electronic devices within a deterministic state of operation. Traditionally, measuring the quiescent current (Iddq) of a device has been employed in manufacturing tests to detect defective parts prior to deployment to the field. However, the monitoring of the deterministic power signature (i.e. boot up or during a self-test routine) has never been exploited to monitor the health of a device in …

Experimental Study Of The Response Of Semiconductor Detectors For Edxrf Analysis., Sunil Kumar Valaparla

Open Access Theses & Dissertations

This present work relates to the study and characterization of the response function of an energy-dispersive x-ray spectrometer. The problems of energy, efficiency and resolution calibration of the system operating in the energy (5-60 keV) range are discussed. We present the operation characteristics of the portable pyro-electric x-ray generator (COOL-X) and the application of the calibrated response spectrum in the elemental analysis using X-ray Fluorescence (XRF).

We study the response of the Si(Li)-Pin XR-100CR semiconductor detector to low energy photons. The photopeak efficiency was determined experimentally by using radioisotopes and compared against a theoretical efficiency curve. The efficiency for gamma …

Silica Removal From Brine By Using Ion Exchange, Carlos R. Acevedo

Open Access Theses & Dissertations

Local governments have been forced to look for additional water sources to satisfy the ever increasing demand for fresh water. Very often, the new water sources such as the underground water in continental territories have high salt content. Currently, reverse osmosis technology (RO) is one of the most common processes for water desalination. However, this process is limited by high silica and salt concentrations in water. At high concentrations silica clogs the membranes used in the RO process, reducing their life and increasing operational costs. In this study, quaternary ammonium resins and sulfonic acid resins were used to remove silica …

Effect Of Air Addition On Plasma-Based Reforming Of Methane And Propane, Atul Vitthalrao Ambhore

Open Access Theses & Dissertations

No abstract provided.

An Integrated Software Package For Model-Based Neuro-Fuzzy Classification Of Small Airway Dysfunction, Nazila Hafezi

Open Access Theses & Dissertations

Respiratory disorders can be difficult to differentiate, as their symptoms are sometimes similar to one another. Concerning asthma which is the major interest in this research, early detection of small airway impairment could greatly help with timely diagnosis. In this research, an integrated software package (ISP) has been developed to help clinicians in classification of asthma severities using Impulse Oscillation data.

The ISP has been developed based on object-oriented methodology. In this package, IOS "diagnostic" parameters such as AX and frequency-dependence of resistance as well as parameter estimates of extended RIC (eRIC) and augmented RIC (aRIC) models (simplified cases of …

Multi-Objective Network Reliability Optimization Using Evolutionary Algorithms, Franciso Oswaldo Aguirre

Open Access Theses & Dissertations

This work presents a new multiple objective evolutionary algorithm to solve three well known network reliability allocation problems considering different conflicting objectives to be optimized simultaneously. The new algorithm is applied in the design of a telecommunication network that is formed for several stations or nodes interconnected by telecommunication links or paths. The problem presented in this work involves finding which links to activate in order to obtain connectivity in the nodes. The number of nodes that need to be connected depends of the case that is being evaluated. The three network reliability problems considered are: all-terminal, k-terminal, and two-terminal. …

Sustainable Development Extension Plan (Sudex): Community Mobilization Through Proactive Participation And Synergistic Alliance To Alliviate Poverty And Achieve Sustainable Self Sufficiency, Stephen Forbes

Open Access Theses & Dissertations

This Dissertation describes a sustainable development extension plan (Sudex Plan) to help communities in developing countries achieve Goal 1 of the United Nation's Millennium Development Goals (MDG). Goal 1 focuses on reducing poverty and hunger by 50% by the year 2015, but all the MDG are interrelated and one can not be achieved without considering the others, and to attain any is an empty accomplishment without ways to ensure that they can be sustained and continuously improved with the means to pass on the information, knowledge and lessons learned from community to community, generation to generation. The Sudex Plan is …

Directional Analysis And Filtering For Dust Storm Detection In Noaa-Avhrr Imagery, Swapna Janugani

Open Access Theses & Dissertations

In this research, we propose spatio-spectral processing techniques for the detection of dust storms in 5-band NOAA-AVHRR imagery. The research is mainly focused on locating the dust sources and automatically finding the transport direction of the dust storm. Previous methods that use simple band math analysis have produced promising results but have some drawback in producing consistent results when low SNR images are used. Moreover, in seeking to automate the dust storm detection, the presence of clouds in the vicinity of the dust storm creates a challenge in being able to distinguish these two types of image texture. Our research …

Novel Approach To Predict The Crash Testing Data Using Multiple Regression Analysis And Principal Component Analysis, Ravi Lochan Kallur

Open Access Theses & Dissertations

In the design process of vehicles, crash tests are very critical to determine the safety measures. Every motor manufacturing company has to maintain certain standards for their autos. This will lead to the design optimization of safety measures utilizing the data available from crash tests. The engineers perform various experiments to generate data from crash testing of vehicles in their manufacturing facility. With the help of simulators; they create a virtual environment to perform design changes. Hence the data obtained from the crash tests is vital in design optimization of safety systems. The present study deals with the technologies involved …

Buckling Of Dome Structure With Opening, Under Wind Load, Anup Ramesh Marathe

Open Access Theses & Dissertations

Double layered parabolic dome structure, with opening in roof is analyzed for buckling under wind load. Domes with three different opening sizes are used and external wind load is applied from different directions without changing the position of the opening. Dead load and internal wind pressure is also applied. The dead load and internal wind pressure is kept constant. The internal wind pressure is applied as per the ASCE building requirement that is once in positive direction which is towards the surface and once in negative direction which is away from the surface. The data for this project was sent …

Spatio-Temporal Ecg Analysis For Localization Of Arrhythmias Using Precordial Ecg Leads And 128-Lead Systems, Eduardo Morales

Open Access Theses & Dissertations

A novel and state-of-the-art approach for the analysis of cardiac arrhythmias is proposed. Currently, the analysis of the electrocardiogram is only performed in the time-domain. The proposed method improves the electrocardiogram analysis by adding spatial properties. The spatial properties added to the electrocardiogram allow for the analysis of specific regions inside the human heart where cardiac arrhythmias are suspected to have occurred. In this Dissertation, the concept of electrocardiography was extended using advanced bioelectromagnetism theory. In concrete, the multiple dipole model of the human heart was used to extend the concept of electrocardiography from a temporal analysis to a spatial-temporal …

An Enhanced Method For The Existing Bluetooth Pairing Protocol To Avoid Impersonation Attacks, Patricia Aidee Mendoza

Open Access Theses & Dissertations

As the use of the Bluetooth technology in wireless technologies such as computers, cell phones, personal digital assistants (PDAs), printers, digital cameras, PC peripherals, and headphones, among others, has enormously increased during this decade, it has also increased the need of employing a more secure and robust pairing protocol that protects the transfer of information between Bluetooth devices.

The existing Bluetooth pairing protocol starts when a Bluetooth device is set to be in discoverable mode and it is found by another device. After this step is completed, it initiates the pairing procedure by sharing some important device information, then by …

Analysis Of Cluster Compute Nodes With Varying Memory Hierarchy Distributions, Jon Valentin Ramirez

Open Access Theses & Dissertations

This Thesis compares a Compute Node, a cluster compute node that can completely contain smaller processes within, but not larger ones, with a Memory Node, a cluster compute node that can fully contain large processes within main memory. The Compute Node and Memory Node are tested by executing matrix multiplication programs that range in size from small processes similar to jobs that can be run on a single workstation to large processes that would only fit entirely within a Memory Node. Memory was allocated using four types of memory allocation: static, external, dynamic, and automatic. This analysis provides a measure …

Assessment Of Super-Resolution For Face Recognition From Very-Low Resoution Images, James Roger Roeder

Open Access Theses & Dissertations

Super-Resolution (SR) involves the registration of multiple images/frames and reconstruction of a single higher resolution image. The goal of this research is to use multiple, very-low resolution images, such as those produced from a video sequence in a wireless sensor network system, as input to the super-resolution process in a face recognition system. The algorithm used for face recognition is the Fisherfaces method with a nearest neighbor classifier used for the recognition decision. Super-resolution consists of two stages, a registration stage and a reconstruction stage.

The testing images were segmented using a simple skin color detection approach. After the cropping, …

Characterization Of High Resolution Range And Doppler Chaotic Ladar, Berenice Verdin

Open Access Theses & Dissertations

Compared to high range resolution radar systems, chaotic LADAR (laser detection and ranging) has the potential of providing an increase in range-Doppler resolution by several orders of magnitude.

The purpose of this project is to determine system parameters and signal processing schemes required to build a high resolution chaotic LADAR. Specifically, the LADAR is based on a semiconductor laser that generates a wideband chaotic signal via optical feedback. The behavior of the laser output is modeled by changing the control parameters of the delay differential equations that dictate the behavior of the laser output. Depending on the feedback level and …

Characterization And Cytotoxic Assessment Of Ballistic Aerosolized Particulates For Tungsten Alloy Penetrators Interacting With Steel Targets, Brenda Ivette Machado

Open Access Theses & Dissertations

The aerosolized particulates produced during an impact of depleted uranium munitions can potentially contaminate extensive areas around the impact sites and cause a wide spectrum of civilian and military damage. Thus materials such as WHA have been prompted for consideration. The present research is concerned with the regular collection of aerosol particulates associated with ballistic WHA rod penetration into rolled homogeneous steel (RHA) or other related steel armor as armor plate sequences. Particulate size characterization via scanning electron microscopy (SEM) and transmission electron microscopy (TEM) along with chemical compositions via energy dispersive spectroscopy (EDS) were the focus of this research. …

Retrofitting A Stereolithography System Within A Laminar Flow Hood, Mahesh Pandurang Tonde

Open Access Theses & Dissertations

This research focused on retrofitting the stereolithography (SL), a rapid prototyping technology, inside a laminar flow hood to provide an aseptic, particulate-free environment for scaffold fabrication. Two of the important objectives of this project were to retrofit the commercial SLA 250/30 inside a laminar flow hood to demonstrate that the manufacturability of the Bio-SL system was comparable to original SLA 250 system and to conduct the sterility test on fabricated scaffolds to show that the laminar flow hood was able to provide an aseptic, particulate-free environment for the fabrication.

Fabrication And Characterization Of Zirconium Oxide Thin Films, Vemnkata Rama Sesha Ravi Kumar Vemuri

Open Access Theses & Dissertations

Zirconium oxide (ZrO2) is an important material with a potential for a wide range of technological applications. The outstanding chemical stability, electrical and mechanical properties, high dielectric constant, and wide band gap of ZrO2 make it suitable for several industrial applications in the field of optics, electronics, magneto-electronics, and optoelectronics. ZrO2 is frequently used as a high refractive index material in multilayer optical coatings in high power laser systems. ZrO2 is employed in super plastic structural ceramics that demonstrate excellent strength and fracture toughness. ZrO2 has been considered as a promising dielectric to replace SiO2 in advanced metal oxide semiconductor …

Multiple Objective Optimization Of Performance Based Logistics, Delia Villanueva

Open Access Theses & Dissertations

This thesis presents a new Performance Based Logistics optimization model. Performance Based Logistics (PBL) is becoming increasingly important for manufacturers in mission critical environments that need to provide ultimate product availability at the lowest cost and with the highest level of customer satisfaction. The U.S. Department of Defense has mandated that Performance Based Logistics programs be adopted by its major weapon systems and equipment suppliers, is one of the newest support strategies to improve the weapon system readiness. This work presents a new multiple objective evolutionary approach that simultaneously optimizes objectives such as Reliability, Maintainability and Total Cost for Ownership. …

An Investigation On The Mixing Hydrodynamics Of A Gas-Solid Fluidized Bed, Mario Alberto Ruvalcaba

Open Access Theses & Dissertations

In previous decades, the experimental and numerical studies of multiphase flows have remarkably increased especially gas-solid flows. Research of this type has abundant applications in energy, chemical processes, among others. Moreover, common applications include fluid catalytic cracking for petroleum refineries, fluidized bed reactors (type of chemical reactors), interface modification, such as applying a coating onto solid items, and an important technology breakthrough in coal gasification. The work presented on this thesis concentrates on the investigation of gas-solid flows utilizing Computational Fluid Dynamics (CFD) methods. The gas-solid flows studies performed on this investigation assumed the solid phase as a continuum with …

Verification Of Nyslab A Software For The Analysis Of Jointed Pavements, Maryam Limouee

Open Access Theses & Dissertations

A significant amount of research and development has been conducted for decades to provide a tool for the design and analysis of jointed slabs on different types of foundations. ILLI-SLAB, JSLAB, EverFE and ISLAB are the most used finite element modeling (FEM) codes that have gone through several iterations of improvement. JSLAB has been maintained by the Federal Highway Administration (FHWA) and is distributed free of charge and there is significant interest in further improving the capabilities of that software package.

Researchers at the University of Texas at El Paso have been charged to implement several modifications in the latest …

Insight Into The Physics Of Rupture: Dynamic Triggering Seismicity, Hector Gonzalez-Huizar

Open Access Theses & Dissertations

Seismic waves can trigger earthquakes and tremor at large distances from the causable event. Dynamic triggering occurs when the surface waves from large earthquakes change the stresses conditions on previously overstressed faults, promoting failure. To understand the causative stresses and environments behind dynamic triggering, we model the change in the stress field that the passing of Rayleigh and Love waves cause on a fault plane of arbitrary orientation relative to the direction of propagation of the waves, and apply a Coulomb failure criterion to calculate the potential of these stress changes to trigger seismicity. We apply our model to three …

Asset Management Application Towards An Improved Right Of Way Acquisition, Dora Oralia Francis

Open Access Theses & Dissertations

The purpose of this research is to discover a most suitable approach when the right of way acquisition process begins. As soon as it is known that the right of way acquisitions begin, speculations are made to parcels in order to increase the values of these parcel. Different types of speculations can be made, at a different phase of the right of way (ROW) acquisition process. The parcel cost can vary due to speculations according to the phase of the right of way acquisition process. To help assist the Texas Department of Transportation (TxDOT) on the right of way acquisition …

Art In A New Light: Design And Assessment Of Illuminants To Reduce Photochemical Degradation Of Works Of Art, Monica Fabiola Delgado

Open Access Theses & Dissertations

The purpose of this research is to design the best lighting that will minimize long term photochemical degradation of Old Master Drawings and/or other works of art, while maintaining the patron's appreciation of the object's color and detail. The present approach is a technological refinement to the basic underlying earlier work on fluorescent lighting by W. A. Thornton, W.A. at General Electric1. Thin-film dielectric, multi-coating technology is used to create filters that eliminate ultraviolet light, near infrared light and significant unnecessary parts from the visible spectrum, thus maximizing the reduction in photochemical degradation, while maintaining optimal color rendering. Three interference …

Additive Layer Manufacturing Of Ti-6al-4v By Electron Beam Melting From Powder Particles: Solid, Mesh And Foam Components Study, Sara M. Gaytan

Open Access Theses & Dissertations

Additive Manufacturing by Electron Beam Melting Rapid Manufacturing is a technology that consists of the fabrication of a CAD design by melting powder particles in a layer by layer fashion. In this study, Ti-6Al-4V has been utilized to fabricate solid, mesh and foam components by EBM technologies. Powder analysis of Ti-6Al-4V was performed to obtain a better understanding of the porosity obtained by the system. After proper optimization of the machine, and porosity control, microstructural analysis was performed to the components already mentioned and correlated by transmission electron microscopy. Besides the microstructural analysis, tensile and hardness testing was performed to …

Hybrid Approach For Site Selection Using Impact Assessment And Principal Component Analysis, Ugandhar Reddy Kondamadugula

Open Access Theses & Dissertations

Principle component analysis (PCA) is used to analyze week data of emission of particulate material from the Residential community. In this Thesis we selected five sites maps where sensors are arranged to collect particulate materials PM0.25, PM 10.Impact Assessment on the site areas are done in the first case,the results Impact Assessment on the site shows that the Global warming potential is really high at the site when the analysis is run for hundred years the Global warming potential has a very high impact on Environment leading to various health hazards. Secondly Principal Component Analysis is used to find out …

Assessing Repeatability Of Four-Point Bending Method For Estimating Fatigue Cracking Of Hot Mix Asphalt, Sara -. Montazeri

Open Access Theses & Dissertations

The objective of this thesis was to assess the repeatability of four-point bending method for estimating fatigue cracking of hot mix asphalt. This experimental research examined the influence of mix proportions, specifically asphalt and air void contents, on fatigue behavior of asphalt beam specimens in the laboratory tested with four-point bending method of loading. Following the relevant specifications, the strain-controlled mode of loading was selected. Fatigue failure is expected to occur at the cycle which the flexural stiffness of asphalt specimen reduced to 50% of initial amount. Up to a 1,000,000 cycles of loading were applied to each specimen.

Different …