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Articles 82531 - 82560 of 196763

Full-Text Articles in Engineering

Voltage Regulation Of Unbalanced Distribution Network With Distributed Generators Through Genetic Algorithm, Islam Ali Jan 2018

Voltage Regulation Of Unbalanced Distribution Network With Distributed Generators Through Genetic Algorithm, Islam Ali

Dissertations and Theses @ UNI

Energy demand has rapidly increased since the manufacturing revolution in the 19th century. One of the higher energy demands is electricity. The great majority of devices in the manufacturing field run on electricity. The vertically integrated grid paradigm has to be changed to supply the increase in the electrical demand residentially and commercially. Distributed generators (DG) such as Photovoltic (PV) is used to supply the increase in the electrical demand. Photovoltaic (PV) is one of the fast growing distributed generators (DG) as a renewable energy source. However, installing many PV systems to the distribution system can cause power quality problems …


The Need For Enhanced Physical Infrastructure In The United States, Tanvi Gandham Jan 2018

The Need For Enhanced Physical Infrastructure In The United States, Tanvi Gandham

CMC Senior Theses

An examination of necessary infrastructure improvements in the United States.


Developing A Recurrent Neural Network With High Accuracy For Binary Sentiment Analysis, Kevin Cunanan Jan 2018

Developing A Recurrent Neural Network With High Accuracy For Binary Sentiment Analysis, Kevin Cunanan

CMC Senior Theses

Sentiment analysis has taken on various machine learning approaches in order to optimize accuracy, precision, and recall. However, Long Short-Term Memory (LSTM) Recurrent Neural Networks (RNNs) account for the context of a sentence by using previous predictions as additional input for future sentence predictions. Our approach focused on developing an LSTM RNN that could perform binary sentiment analysis for positively and negatively labeled sentences. In collaboration with Mariam Salloum, I developed a collection of programs to classify individual sentences as either positive or negative. This paper additionally looks into machine learning, neural networks, data preprocessing, implementation, and resulting comparisons.


Changes In Nadph Oxidase (Nox) Protein Isoforms And Downstream Reactions As Function Of Time And Overpressure In Blast Tbi, Smit Prakash Shah Jan 2018

Changes In Nadph Oxidase (Nox) Protein Isoforms And Downstream Reactions As Function Of Time And Overpressure In Blast Tbi, Smit Prakash Shah

Theses

Blast-induced Traumatic brain injury (bTBI) is a leading cause of morbidity in soldiers on the battlefield and training sites with long-term neurological and psychological pathologies. Among many pathological sequela of blast TBI, oxidative stress has been identified as a major factor contributing to the pathophysiology of bTBI. Recent studies have demonstrated activation of oxidative stress pathways following blast injury but their distribution among different brain regions as function of post injury time and Blast over pressure (BOP) have not been explored. The present study examines the protein expression of NADP oxidase (NOX) isoforms 1 & 2, corresponding superoxide production, a …


Predictive Modeling On The Piezoelectric Properties Of 3d Printed Functional Nanocomposites Using The Data Analytics Approach, Md Didarul Islam Jan 2018

Predictive Modeling On The Piezoelectric Properties Of 3d Printed Functional Nanocomposites Using The Data Analytics Approach, Md Didarul Islam

Open Access Theses & Dissertations

This paper presents research done on prediction modeling using a data analytics approach to determine various factors affecting the piezoelectric properties of the 3D printed pressure sensors. Previously, the material extrusion 3D printing technique was used to fabricate pressure sensors composed of multiwall carbon nanotubes (CNT), barium titanate (BT), and polyvinylidene fluoride (PVDF) using simple fabrication and low-cost methods. This sensor produced a voltage output of 725 mV (0.13 pC/N) which is enough for pressure sensing applications. However, a holistic study to determine impacts of all factors was not carried out in the previous model. In this study, the design …


Analysis Of High Performance Scientific Programming Workflows, Withana Kankanamalage Umayanganie Klaassen Jan 2018

Analysis Of High Performance Scientific Programming Workflows, Withana Kankanamalage Umayanganie Klaassen

Open Access Theses & Dissertations

Substantial time is spent on building, optimizing and maintaining large-scale software that is run on supercomputers. However, little has been done to utilize overall resources efficiently when it comes to including expensive human resources. The community is beginning to acknowledge that optimizing the hardware performance such as speed and memory bottlenecks contributes less to the overall productivity than does the development lifecycle of high-performance scientific applications. Researchers are beginning to look at overall scientific workflows for high performance computing. Scientific programming productivity is measured by time and effort required to develop, configure, and maintain a simulation experiment and its constituent …


Effects Of Air And Other Gases In The Stabilization Process Of The Superprotonic Phase Of Cesium Dihydrogen Phosphate Within A Hermetically Sealed Chamber, Israel Martinez Jan 2018

Effects Of Air And Other Gases In The Stabilization Process Of The Superprotonic Phase Of Cesium Dihydrogen Phosphate Within A Hermetically Sealed Chamber, Israel Martinez

Open Access Theses & Dissertations

The solid acid CsH2PO4 (CDP), exhibits a sudden increase in its proton conductivity as it’s heated above a certain temperature (around T~235oC), which makes it a very attractive candidate to be used as an electrolyte in intermediate temperature fuel cells. Unfortunately, at these temperatures the sample is not stable, as starts to dehydrate; which causes a dramatic drop in the proton conductivity over a short period of time (less than one hour). In order to inhibit, or at least delay, the dehydration process, the solid acid it’s put under a saturated water vapor atmosphere. Another method to stabilize the highly …


Magnetic And Catalytic Properties Of Transition Metal Doped Mos2 Nanocrystals, Luis Martinez Jan 2018

Magnetic And Catalytic Properties Of Transition Metal Doped Mos2 Nanocrystals, Luis Martinez

Open Access Theses & Dissertations

Magnetism and catalytic activity of nanoscale layered two-dimensional (2D) transition metal dichalcogenides (TMDs) have gained an increasing research interest in the recent past. To broaden the current knowledge and understanding on this subject, in this work, together with my collaborators, I study the magnetic and electrocatalytic properties of hydrothermally grown pristine and transition metal doped (10% of Co, Ni, Fe and Mn) 2H-MoS2 nanosheets/nanocrystals (NCs), with the particle size of 25-30 nm. A broad range of experimental measurements such as x-ray diffraction, transmission electron microscopy, x-ray photo absorption spectroscopy, Raman spectroscopy, magnetic, catalytic and electron spin resonance have been employed …


Structural Design Of Thrust Measurement System For Cryogenic Rocket Engines, Abner Jael Moreno Tarango Jan 2018

Structural Design Of Thrust Measurement System For Cryogenic Rocket Engines, Abner Jael Moreno Tarango

Open Access Theses & Dissertations

The Center for Space Exploration and Technology Research (cSETR) at The University of Texas at El Paso (UTEP) has been the leader in academia on the development of Liquid Oxygen (LO2) and Liquid Methane (LCH4) propulsion technologies. One of the projects being developed at cSETR is a suborbital vehicle whose mission is to evaluate performance parameters, demonstrate restart capability, and demonstrate the propulsion system operation in microgravity. This vehicle, called Daedalus, will use a 500-lbf LO2-LCH4 rocket engine that can be throttled down to 100-lbf. To accomplish this goal, UTEP partnered with the El Paso County to lease a plot …


Shape Detection Of Structural Electronics Using Machine Vision System Embeded Into Scara Robot, Varaha Venkat Vyas Kumar Naidu Jan 2018

Shape Detection Of Structural Electronics Using Machine Vision System Embeded Into Scara Robot, Varaha Venkat Vyas Kumar Naidu

Open Access Theses & Dissertations

Additive manufacturing processes combined with enhanced technologies for electronics production enables a highly flexible manufacturing of personalized 3D electronic devices. Due to the technical progress within the last years, these technologies made their way from prototyping towards manufacturing. The growing request for products manufactured in batch size, making use of a robot to incorporate the electronic components necessary to make functional 3-Dimensional-Structural Electronics will extend the mass production possibilities. There is significant interest in automation of a process in which parameters are influential in the occurrence of assembly defects and which adjustments should be made to those variables to reduce …


Parallelization And Scalability Analysis Of The \\[1pc] 3d Spatially Variant Lattice Algorithm, Henry Roger Moncada Lopez Jan 2018

Parallelization And Scalability Analysis Of The \\[1pc] 3d Spatially Variant Lattice Algorithm, Henry Roger Moncada Lopez

Open Access Theses & Dissertations

The purpose of this research is to design a faster implementation of an algorithm to generate 3D spatially variant lattices (SVL) and improve its performance when it is running on a parallel computer system. The algorithm is used to synthesize a SVL for a periodic structure. The algorithm has the ability to spatially vary the unit cell, the orientation of the unit cells, lattice spacing, fill fraction, material composition, and lattice symmetry. The algorithm produces a lattice that is smooth, continuous and free of defects. The lattice spacing remains strikingly uniform even when the lattice is spatially varied. This is …


Economic And Environmentally Efficient Energy Management System For Optimal Microgrid Operation, Olayinka Samuel Obafemi Jan 2018

Economic And Environmentally Efficient Energy Management System For Optimal Microgrid Operation, Olayinka Samuel Obafemi

Open Access Theses & Dissertations

The aim of this Thesis is to study and understand the economic analysis of integrating renewable energy resources for the purpose of improving the system grid, identifying and monetizing benefits and cost. This Thesis discusses the approach taken and solution created to tackle the current problems facing the production and consumption of electricity and how the microgrid has become a platform for improvement in power system operation. A microgrid in islanded and connected mode are simulated using Homer Pro for optimization and its results help gain an insight into analyzing and monetizing cost and benefits with one common goal in …


The Design Of A Rocket Propulsion Labview Data Acquisition And Control System, Dylan Allan Ott Jan 2018

The Design Of A Rocket Propulsion Labview Data Acquisition And Control System, Dylan Allan Ott

Open Access Theses & Dissertations

When designing a rocket engine, both the propulsion system and propellant choice(s) are an important deciding factor. Desired rocket engine behavior, specific impulse, and levels of thrust are all different between the various propulsion systems. A bi-propellant cryogenic liquid 5lbf, 500lbf, and 2000lbf rocket engine was designed and manufactured by UTEP. The 5lbf rocket engine is a Reaction Control Engine and the 500lbf and 2000lbf rocket engine is a throttleable Main Engine. To provide a reliable and safe data acquisition and control system for this experiment, a Real-Time control platform was needed. A compact DAQ system was purchased and configured …


Fracture Mechanics Of Heterogeneous Composites, Md Fazle Rabbi Jan 2018

Fracture Mechanics Of Heterogeneous Composites, Md Fazle Rabbi

Open Access Theses & Dissertations

The increasing application of composite materials due to their ubiquitous advance in terms of mechanical and thermal properties has brought attention to the fracture mechanics of the materials possessing heterogeneity. Recent investigations have focused on the micro- and macro-mechanism of fracture in heterogeneous composites (HCs). In this study, the fracture mechanics of the two HCs: Polymer bonded explosive (PBX) simulant and hot mixed asphalt (HMA) are evaluated on the macroscopic scale. It is an interest of Sandia National Laboratory to examine the fracture resistance of PBXs, particularly those of varying composition and subjected to aging. In this research, a batch …


Solvent And Concentration Effects Governing The Hierarchical Organization Of Asphaltenes: A Small-Angle X-Ray Scattering Study, Hasan Rejoanur Rahman Jan 2018

Solvent And Concentration Effects Governing The Hierarchical Organization Of Asphaltenes: A Small-Angle X-Ray Scattering Study, Hasan Rejoanur Rahman

Open Access Theses & Dissertations

Asphaltenes are a group of planar molecules found in crude oil and are prone to aggregation which often causes blockage of pipes along the oil production stream resulting a huge economic downside. In an effort to understand the hierarchical organization of asphaltene in different solvents and concentrations, the solution structure of various asphaltene solutions were studied using small-angle x-ray scattering (SAXS). Solvents were chosen based on miscibility maps. Such maps are generated on the critical value of the solubility parameter difference between asphaltenes or asphaltene components, and a range of solvents. The critical factors that affect asphaltene and asphaltene component …


Optimization For The Allocation Of Funds For Pavement Maintenance In Pavement Management Systems, Armando Ramirez Jan 2018

Optimization For The Allocation Of Funds For Pavement Maintenance In Pavement Management Systems, Armando Ramirez

Open Access Theses & Dissertations

Pavement maintenance and rehabilitation are critical and costly elements for highway agencies. A challenge for transportation agencies is to preserve roadways in an appropriate condition and extend the pavement service life while maintaining the safety and satisfaction of its users, and maximize the benefits obtained by the repair investments. Pavement maintenance programming is increasing in complexity due to limited resources and increments in traffic and population. Management decisions are usually based on personal judgment by pavement managers and sometimes those decisions are not even supported by previous experience. Research shows that optimization methods can produce significant benefits when transportation agencies …


Multi-State Multi-Objective Reliability Analysis Of Renewable Energy Systems, Luis Ramirez Jan 2018

Multi-State Multi-Objective Reliability Analysis Of Renewable Energy Systems, Luis Ramirez

Open Access Theses & Dissertations

This work presents a new multi-objective evolutionary algorithm (MOEA), capable of obtaining a system's reliability while considering other objectives that concurrently need to be optimized. The algorithm is applied in two different case studies. One of the problems considers a multi-state, multi-objective renewable energy system which tries to find a configuration between solar panels and wind turbines that maximizes the system's reliability of achieving specific energy demand, while also minimizes the purchasing cost of the system. The second case study analyzes a flexible manufacturing system that contains different machines that can perform different functions. The primary objective is to obtain …


The Effect Of Data Marshalling On Computation Offloading Decisions, Julio Alberto Reyes Muñoz Jan 2018

The Effect Of Data Marshalling On Computation Offloading Decisions, Julio Alberto Reyes Muñoz

Open Access Theses & Dissertations

Computation offloading consists in allowing resource constrained computers, such as smartphones and other mobile devices, to use the network for the remote execution of resource intensive computing tasks in powerful computers. However, deciding whether to offload or not is not a trivial problem, and it depends in several variables related to the environment conditions, the computing devices involved in the process, and the nature of the task to be remotely executed. Furthermore, it comprises the optimal solution to some questions, like how to partition the application and where to execute the tasks.

The computation offloading decision problem has been widely …


Tribological Characterization Of Ti-Based Alloys For Biomedical Applications In Simulated Body Fluid, Edgar Reyes Jan 2018

Tribological Characterization Of Ti-Based Alloys For Biomedical Applications In Simulated Body Fluid, Edgar Reyes

Open Access Theses & Dissertations

Tribology is a terminology introduced in the 1960's and it is a study that relates to the investigation of the damage of materials. Titanium, as a material used for a wide range of application, it has been brought to the attention of researchers some characteristics such as its much lower density if compared to steel, its capability as an alloying agent with an amount of metals to enhance physical and mechanical properties, to name just a few characteristics. This paper will discuss the performance on tribology behavior in two different Titanium alloys. These Titanium alloys are Ti-6Al-4V (Ti64), and Ti-24Nb-4Zr-8Sn …


A Quality Control Performance-Based Methodology For Pavement Management Systems, Edgar Daniel Rodriguez Velasquez Jan 2018

A Quality Control Performance-Based Methodology For Pavement Management Systems, Edgar Daniel Rodriguez Velasquez

Open Access Theses & Dissertations

Transportation Asset Management is a decision-making process, which allocates available resources for operating, maintaining, enhancing, and expanding transportation infrastructure while considering its entire life cycle. Transportation infrastructure includes different types of assets and pavements are one of the main assets due to its social, economic, and environmental impacts to society. Transportation agencies implement Pavement Management Systems to support the pavement management process. While implementing and operating a Pavement Management System, one of the costliest procedures is collecting pavement condition data from the field. Good quality for pavement condition data is required to select the right preservation treatments, estimate the associated …


Evaluation Of Powdered Activated Carbon For Control Of Taste And Odors Caused By Geosmin, Anthony Joe Rodriguez Jan 2018

Evaluation Of Powdered Activated Carbon For Control Of Taste And Odors Caused By Geosmin, Anthony Joe Rodriguez

Open Access Theses & Dissertations

The primary sources of taste and odor problems associated with surface water supplies spawn from algae and bacterial blooms that secrete odorous chemicals such as Geosmin and MIB. These musty, odorous, organic compounds are usually detectable by the human nose at concentrations of 5 to 10 ppt and can create considerable concern by consumers that can lead to complaints and misconceptions of odors as a water quality problem. Typically, since chemical or ozone treatment can be costly, activated carbon (powdered or granular) is generally employed in the process of removing organic compounds, such as Geosmin and MIB. The research presented …


Understanding The Consequences And Costs Of Climate Change On Texas Pavements, Megha Sharma Jan 2018

Understanding The Consequences And Costs Of Climate Change On Texas Pavements, Megha Sharma

Open Access Theses & Dissertations

Over the several centuries, the global temperatures have been rising, and the rate of rising in temperature has increased significantly in the last century. The increase in temperature and precipitation can substantially influence performance life of pavements because of their continuous exposure to climate. The climate parameters like temperature and precipitation are considered in the pavement design to reflect the influence of climate factors on the performance of the pavements. Currently, designers use the historical weather patterns while designing pavements. Since the climate is changing, the estimated service life of the pavement will be reduced significantly if the historical data …


Evaluation Of Orthophosphate Based Corrosion Inhibitors In Treated Water For El Paso Region, Francisco Solis Jr Jan 2018

Evaluation Of Orthophosphate Based Corrosion Inhibitors In Treated Water For El Paso Region, Francisco Solis Jr

Open Access Theses & Dissertations

Corrosion is an electrochemical phenomenon that involves the deterioration of a metal by the reaction of itself with its surrounding environment. One of the greatest issues for water utilities around the country is to keep the water quality safe. Corrosion can affect the quality of the water that we use on a daily basis by adding a bad taste, increasing the concentration of heavy metals, and allowing outside contaminants to enter the distribution system. The use of phosphate based corrosion inhibitors was tested in two different metals: iron and copper. The phosphate in the inhibitors react with the calcium in …


An Integrated Study Towards Curing Neurodegenerative Disorders Using Materials Science And Stem Cell-Based Tissue Engineering Approaches, Nishat Tasnim Jan 2018

An Integrated Study Towards Curing Neurodegenerative Disorders Using Materials Science And Stem Cell-Based Tissue Engineering Approaches, Nishat Tasnim

Open Access Theses & Dissertations

Neurodegenerative diseases affect around one billion people globally that are characterized by irreversible degeneration of brain tissues. These diseases cause serious effects on patients degrading their brain functions and causing enormous physical and mental health issues. Parkinson's disease (PD) is one of the most common neurodegenerative disorder affecting millions of people worldwide which results from loss of dopaminergic (DA) neurons in the mid-brain. Unfortunately, no medical treatment is effective to date for these significant brain disorders, except some symptomatic therapies only focusing on improving the quality of patient's life.

Two current approaches hold great promise in targeting PD as well …


Tungsten Doping Induced Superior Mechanical Properties Of Hafnium Oxide For Energy Applications, Ann Marie Uribe Jan 2018

Tungsten Doping Induced Superior Mechanical Properties Of Hafnium Oxide For Energy Applications, Ann Marie Uribe

Open Access Theses & Dissertations

Hafnium oxide, or hafnia, is a high temperature refractory material with good electrical, chemical, optical, and thermodynamic properties. The effects of dopants have been widely studied, especially after the discovery of ferroelectricity induced in hafnia thin films. While attractive and used in the opto-electronic, memory devices, and semiconductor industries, there is a lack in the literature on enhancing the mechanical properties of hafnium oxide, specifically through doping it with tungsten, another material of interest particularly for future high temperature device applications. Thus, this work aimed to grow hafnia thin films doped with varying amounts of tungsten. The samples were grown …


Decision Making For Dynamic Systems Under Uncertainty: Predictions And Parameter Recomputations, Leobardo Valera Jan 2018

Decision Making For Dynamic Systems Under Uncertainty: Predictions And Parameter Recomputations, Leobardo Valera

Open Access Theses & Dissertations

In this Thesis, we are interested in making decision over a model of a dynamic system. We want to know, on one hand, how the corresponding dynamic phenomenon unfolds under different input parameters (simulations). These simulations might help researchers to design devices with a better performance than the actual ones. On the other hand, we are also interested in predicting the behavior of the dynamic system based on knowledge of the phenomenon in order to prevent undesired outcomes. Finally, this Thesis is concerned with the identification of parameters of dynamic systems that ensure a specific performance or behavior.

Understanding the …


Investigating Early Age Behavior Of Portland Cement Concrete In Arid Regions, Evan Wolf Jan 2018

Investigating Early Age Behavior Of Portland Cement Concrete In Arid Regions, Evan Wolf

Open Access Theses & Dissertations

The early-age behavior and properties of portland cement concrete change rapidly over time as a result of the hydration process. Comprised of a series of chemical reactions, this process accelerates nonlinearly with the curing temperature. Gaining knowledge and understanding of the phases of the hydration process (i.e., dormant, setting, and hardening) plays an important role in the timely opening of roads, resuming of construction, and achieving long-term performance. Standard tests such as ASTM C403 arbitrarily define the time of initial and final setting of concrete. Despite decades of studies concerning setting times, actual predictions still span hours, while the quality …


Effects Of Gradation And Moisture Content On Resistivity Of Mechanically Stabilized Earth Wall Backfill Materials, Jose Luis Arciniega Jan 2018

Effects Of Gradation And Moisture Content On Resistivity Of Mechanically Stabilized Earth Wall Backfill Materials, Jose Luis Arciniega

Open Access Theses & Dissertations

The service life of mechanically stabilized earth (MSE) walls depends on the corrosion rate of the metallic reinforcement used in their construction. The resistivity of the backfill aggregates needs to be measured accurately in order to estimate realistically the corrosion rate of the reinforcement. Resistivity testing is usually performed using the traditional soil box on the portion of the aggregates that passes a No. 10 or No. 8 sieve to either select or reject the backfill. For a more reasonable characterization of the corrosivity of coarse backfills, it is desirable to use their actual gradations. To that end, several resistivity …


Influence Of Mix Design Parameters On Performance Of Balanced Asphalt Mixtures, Luiza Helena Barros Jan 2018

Influence Of Mix Design Parameters On Performance Of Balanced Asphalt Mixtures, Luiza Helena Barros

Open Access Theses & Dissertations

With the popularity of the Balanced Mix Design (BMD) concept, the need for performance tests that can reliably evaluate the cracking and rutting potentials of asphalt concrete (AC) mixes has become more critical. A great deal of effort has been focused on incorporating test methods that can potentially improve the current AC mix-design processes and consequently screen underperforming AC mixes. However, the influence of mix design parameters on the performanceof BMD mixes that provide pavement engineers and designers with thorough guidelines and a reliable and consistent test protocol has not been extensively documented.

This Thesis presents an experimental evaluation of …


Photo-Induced Charge Transport In Graphene And Semiconducting Wse2 Integrated With Zero-Dimensional Materials For Enhancing Optoelectronic Device Characteristics, Srishti Chugh Jan 2018

Photo-Induced Charge Transport In Graphene And Semiconducting Wse2 Integrated With Zero-Dimensional Materials For Enhancing Optoelectronic Device Characteristics, Srishti Chugh

Open Access Theses & Dissertations

Two-dimensional (2D) materials encompass a diverse array of properties from the metallic-like character of graphene to the semiconducting nature of many of the transition metal dichalcogenides (TMDCs) such as tungsten diselenide (WSe2). These materials exhibit intriguing interactions with incoming radiation which makes them interesting for electronics and optoelectronics, especially given the high electron mobility and the ballistic nature of the electronic transport under certain conditions. In particular, the semiconducting TMDCs, such as WSe2, express an indirect-to-direct optical transition with scaling from the bulk to monolayers. Despite the enhanced optical absorption characteristics of monolayer WSe2 stemming from its direct band gap, …