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ASU Electronic Theses and Dissertations


This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.

In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.

Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.


Contributor
Subject
Date Range
2010 2020


The larger tolerance to lattice mismatch in growth of semiconductor nanowires (NWs) offers much more flexibility for achieving a wide range of compositions and bandgaps via alloying within a single substrate. The bandgap of III-V InGaAsP alloy NWs can be tuned to cover a wide range of (0.4, 2.25) eV, appealing for various optoelectronic applications such as photodetectors, solar cells, Light Emitting Diodes (LEDs), lasers, etc., given the existing rich knowledge in device fabrication based on these materials. This dissertation explores the growth of InGaAsP alloys using a low-cost method that could be potentially important especially for III-V NW-based solar …

Contributors
Hashemi Amiri, Seyed Ebrahim, Ning, Cun-Zheng, Petuskey, William, et al.
Created Date
2018

III-Nitride nanostructures have been an active area of research recently due to their ability to tune their optoelectronic properties. Thus far work has been done on InGaN quantum dots, nanowires, nanopillars, amongst other structures, but this research reports the creation of a new type of InGaN nanostructure, nanorings. Hexagonal InGaN nanorings were formed using Metal Organic Chemical Vapor Deposition through droplet epitaxy. The nanorings were thoroughly analyzed using x-ray diffraction, photoluminescence, electron microscopy, electron diffraction, and atomic force microscopy. Nanorings with high indium incorporation were achieved with indium content up to 50% that was then controlled using the growth time, …

Contributors
Zaidi, Zohair Azhar, Mahajan, Subhash, O'Connell, Michael J, et al.
Created Date
2012

Robotic systems are outmatched by the abilities of the human hand to perceive and manipulate the world. Human hands are able to physically interact with the world to perceive, learn, and act to accomplish tasks. Limitations of robotic systems to interact with and manipulate the world diminish their usefulness. In order to advance robot end effectors, specifically artificial hands, rich multimodal tactile sensing is needed. In this work, a multi-articulating, anthropomorphic robot testbed was developed for investigating tactile sensory stimuli during finger-object interactions. The artificial finger is controlled by a tendon-driven remote actuation system that allows for modular control of …

Contributors
Hellman, Randall Blake, Santos, Veronica J, Artemiadis, Panagiotis K, et al.
Created Date
2016

For more than twenty years, clinical researchers have been publishing data regarding incidence and risk of adverse events (AEs) incurred during hospitalizations. Hospitals have standard operating policies and procedures (SOPP) to protect patients from AE. The AE specifics (rates, SOPP failures, timing and risk factors) during heart failure (HF) hospitalizations are unknown. There were 1,722 patients discharged with a primary diagnosis of HF from an academic hospital between January 2005 and December 2007. Three hundred eighty-one patients experienced 566 AEs, classified into four categories: medication (43.9%), infection (18.9%), patient care (26.3%), or procedural (10.9%). Three distinct analyses were performed: 1) …

Contributors
Huddleston, Jeanne M., Fowler, John, Montgomery, Douglas, et al.
Created Date
2012

Shunt capacitors are often added in transmission networks at suitable locations to improve the voltage profile. In this thesis, the transmission system in Arizona is considered as a test bed. Many shunt capacitors already exist in the Arizona transmission system and more are planned to be added. Addition of these shunt capacitors may create resonance conditions in response to harmonic voltages and currents. Such resonance, if it occurs, may create problematic issues in the system. It is main objective of this thesis to identify potential problematic effects that could occur after placing new shunt capacitors at selected buses in the …

Contributors
Patil, Hardik Ulhas, Heydt, Gerald T, Karady, George, et al.
Created Date
2015

Vehicles traverse granular media through complex reactions with large numbers of small particles. Many approaches rely on empirical trends derived from wheeled vehicles in well-characterized media. However, the environments of numerous bodies such as Mars or the moon are primarily composed of fines called regolith which require different design considerations. This dissertation discusses research aimed at understanding the role and function of empirical, computational, and theoretical granular physics approaches as they apply to helical geometries, their envelope of applicability, and the development of new laws. First, a static Archimedes screw submerged in granular material (glass beads) is analyzed using two …

Contributors
Thoesen, Andrew Lawrence, Marvi, Hamidreza, Berman, Spring, et al.
Created Date
2019

A primary motivation of research in photovoltaic technology is to obtain higher efficiency photovoltaic devices at reduced cost of production so that solar electricity can be cost competitive. The majority of photovoltaic technologies are based on p-n junction, with efficiency potential being much lower than the thermodynamic limits of individual technologies and thereby providing substantial scope for further improvements in efficiency. The thesis explores photovoltaic devices using new physical processes that rely on thin layers and are capable of attaining the thermodynamic limit of photovoltaic technology. Silicon heterostructure is one of the candidate technologies in which thin films induce a …

Contributors
Ghosh, Kunal, Bowden, Stuart, Honsberg, Christiana, et al.
Created Date
2011

The most important metrics considered for electric vehicles are power density, efficiency, and reliability of the powertrain modules. The powertrain comprises of an Electric Machine (EM), power electronic converters, an Energy Management System (EMS), and an Energy Storage System (ESS). The power electronic converters are used to couple the motor with the battery stack. Including a DC/DC converter in the powertrain module is favored as it adds an additional degree of freedom to achieve flexibility in optimizing the battery module and inverter independently. However, it is essential that the converter is rated for high peak power and can maintain high …

Contributors
Mullangi Chenchu, Hemanth, Ayyanar, Raja, Qin, Jiangchao, et al.
Created Date
2018

A Microbial fuel cell (MFC) is a bio-inspired carbon-neutral, renewable electrochemical converter to extract electricity from catabolic reaction of micro-organisms. It is a promising technology capable of directly converting the abundant biomass on the planet into electricity and potentially alleviate the emerging global warming and energy crisis. The current and power density of MFCs are low compared with conventional energy conversion techniques. Since its debut in 2002, many studies have been performed by adopting a variety of new configurations and structures to improve the power density. The reported maximum areal and volumetric power densities range from 19 mW/m2 to 1.57 …

Contributors
Ren, Hao, Chae, Junseok, Bakkaloglu, Bertan, et al.
Created Date
2016

As wireless communication enters smartphone era, more complicated communication technologies are being used to transmit higher data rate. Power amplifier (PA) has to work in back-off region, while this inevitably reduces battery life for cellphones. Various techniques have been reported to increase PA efficiency, such as envelope elimination and restoration (EER) and envelope tracking (ET). However, state of the art ET supply modulators failed to address high efficiency, high slew rate, and accurate tracking concurrently. In this dissertation, a linear-switch mode hybrid ET supply modulator utilizing adaptive biasing and gain enhanced current mirror operational transconductance amplifier (OTA) with class-AB output …

Contributors
Jing, Yue, Bakkaloglu, Bertan, Kiaei, Sayfe, et al.
Created Date
2017

The problem of systematically designing a control system continues to remain a subject of intense research. In this thesis, a very powerful control system design environment for Linear Time-Invariant (LTI) Multiple-Input Multiple-Output (MIMO) plants is presented. The environment has been designed to address a broad set of closed loop metrics and constraints; e.g. weighted H-infinity closed loop performance subject to closed loop frequency and/or time domain constraints (e.g. peak frequency response, peak overshoot, peak controls, etc.). The general problem considered - a generalized weighted mixed-sensitivity problem subject to constraints - permits designers to directly address and tradeoff multivariable properties at …

Contributors
Puttannaiah, Karan, Rodriguez, Armando A, Tsakalis, Konstantinos S, et al.
Created Date
2013

Parkinson’s disease (PD) is a neurological disorder with complicated and disabling motor and non-motor symptoms. The pathology for PD is difficult and expensive. Furthermore, it depends on patient diaries and the neurologist’s subjective assessment of clinical scales. Objective, accurate, and continuous patient monitoring have become possible with the advancement in mobile and portable equipment. Consequently, a significant amount of work has been done to explore new cost-effective and subjective assessment methods or PD symptoms. For example, smart technologies, such as wearable sensors and optical motion capturing systems, have been used to analyze the symptoms of a PD patient to assess …

Contributors
Deb, Ranadeep, Ogras, Umit Y, Shill, Holly, et al.
Created Date
2019

As a term and method that is rapidly gaining popularity, Building Information Modeling (BIM) is under the scrutiny of many building professionals questioning its potential benefits on their projects. A relevant and accepted calculation methodology and baseline to properly evaluate BIM's benefits have not been established, thus there are mixed perspectives and opinions of the benefits of BIM, creating a general misunderstanding of the expected outcomes. The purpose of this thesis was to develop a more complete methodology to analyze the benefits of BIM, apply recent projects to this methodology to quantify outcomes, resulting in a more a holistic framework …

Contributors
Barlish, Kristen Caroline, Sullivan, Kenneth T., Kashiwagi, Dean T., et al.
Created Date
2011

Renewable portfolio standards prescribe for penetration of high amounts of re-newable energy sources (RES) that may change the structure of existing power systems. The load growth and changes in power flow caused by RES integration may result in re-quirements of new available transmission capabilities and upgrades of existing transmis-sion paths. Construction difficulties of new transmission lines can become a problem in certain locations. The increase of transmission line thermal ratings by reconductoring using High Temperature Low Sag (HTLS) conductors is a comparatively new technology introduced to transmission expansion. A special design permits HTLS conductors to operate at high temperatures (e.g., …

Contributors
Tokombayev, Askhat, Heydt, Gerald T., Sankar, Lalitha, et al.
Created Date
2014

Brain Computer Interfaces are becoming the next generation controllers not only in the medical devices for disabled individuals but also in the gaming and entertainment industries. In order to build an effective Brain Computer Interface, which accurately translates the user thoughts into machine commands, it is important to have robust and fail proof signal processing and machine learning modules which operate on the raw EEG signals and estimate the current thought of the user. In this thesis, several techniques used to perform EEG signal pre-processing, feature extraction and signal classification have been discussed, implemented, validated and verified; efficient supervised machine …

Contributors
Manchala, vamsi krishna, Redkar, Sangram, Rogers, Bradley, et al.
Created Date
2015

Microgrids are a subset of the modern power structure; using distributed generation (DG) to supply power to communities rather than vast regions. The reduced scale mitigates loss allowing the power produced to do more with better control, giving greater security, reliability, and design flexibility. This paper explores the performance and cost viability of a hybrid grid-tied microgrid that utilizes Photovoltaic (PV), batteries, and fuel cell (FC) technology. The concept proposes that each community home is equipped with more PV than is required for normal operation. As the homes are part of a microgrid, excess or unused energy from one home …

Contributors
Patterson, Maxx, Madakannan, Arunachalanadar, Macia, Narciso, et al.
Created Date
2013

Hydrogen fuel cells have been previously investigated as a viable replacement to traditional gas turbine auxiliary power unit onboard fixed wing commercial jets. However, so far no study has attempted to extend their applicability to rotary wing aircrafts. To aid in the advancement of such innovative technologies, a holistic technical approach is required to ensure risk reduction and cost effectiveness throughout the product lifecycle. This paper will evaluate the feasibility of replacing a gas turbine auxiliary power unit on a helicopter with a direct hydrogen, air breathing, proton exchange membrane fuel cell, all while emphasizing a system engineering approach that …

Contributors
Nesheiwat, Rod Bassam, Kannan, Arunachala M, Nam, Changho, et al.
Created Date
2016

The objective of the study was to examine the impact construction document deficiencies have on heavy/civil low-bid infrastructure projects. It encompasses the expertise of 202 heavy/civil construction professionals comprised of contactors and public project owners. The study was designed to determine the frequency and timing of when a contractor discovers construction document deficiencies on heavy/civil low bid projects. The information was correlated with further study data of when a contractor ultimately reports the discovered construction document deficiencies to the public project owner. This research data was compiled and analyzed to determine if contractors are withholding construction document deficiencies from public …

Contributors
Pesek, Anthony Edward, Sullivan, Kenneth, Badger, William, et al.
Created Date
2017

Lower representation of women in the engineering and computer science workforce is a global problem. In the United States, women in engineering drop out at a rate higher than their male counterparts. The male/female ratio in the engineering workforce has remained stagnant despite growing percentages of graduates. Women dropout due to familial responsibilities and they leave to take positions in other industries. In India, women are also employed at a lower rate than men. Many studies address the reasons why women leave, but few studies address why they stay. Those that do, address the personal and organizational characteristics that enable …

Contributors
Ferrell, Joan Leslie, Parmentier, Mary Jane C., Frow, Emma Khamis, et al.
Created Date
2016

Falls are the leading cause of fatal and non-fatal injuries in the older adult population with more than 27,000 fall related deaths reported every year[1]. Adults suffering from lower extremity arthritis have more than twice the likelihood of experiencing multiple falls resulting in increased fall-related injuries compared to healthy adults. People with lower extremity end-stage osteoarthritis(KOA), experience a number of fall risk factors such as knee instability, poor mobility, and knee pain/stiffness. At end-stage knee OA, the space between the bones in the joint of the knee is significantly reduced, resulting in bone to bone frictional wearing causing bone deformation. …

Contributors
Meza, Estefania, Honeycutt, Claire, Lockhart, Thurmon E, et al.
Created Date
2019

Nitrate contamination to groundwater and surface water is a serious problem in areas with high agricultural production due to over application of fertilizers. There is a need for alternative technologies to reduce nutrient runoff without compromising yield. Carbon nanoparticles have adsorptive properties and have shown to improve germination and yield of a variety of crops. Graphite nanoparticles (CNP) were studied under a variety of different fertilizer conditions to grow lettuce for the three seasons of summer, fall, and winter. The aim of this thesis was to quantify the effect of CNPs on nitrate leaching and lettuce growth. This was accomplished …

Contributors
Pandorf, Madelyn, Westerhoff, Paul K, Boyer, Treavor, et al.
Created Date
2018

Graphs are one of the key data structures for many real-world computing applica- tions such as machine learning, social networks, genomics etc. The main challenges of graph processing include diculty in parallelizing the workload that results in work- load imbalance, poor memory locality and very large number of memory accesses. This causes large-scale graph processing to be very expensive. This thesis presents implementation of a select set of graph kernels on a multi-core architecture, Transmuter. The kernels are Breadth-First Search (BFS), Page Rank (PR), and Single Source Shortest Path (SSSP). Transmuter is a multi-tiled architec- ture with 4 tiles and …

Contributors
RENGANATHAN, SRINIDHI, CHAKRABARTI, CHAITALI, Shrivastava, Aviral, et al.
Created Date
2019

The construction industry in India suffers from major time and cost overruns. Data from government and industry reports suggest that projects suffer from 20 to 25 percent time and cost overruns. Waste of resources has been identified as a major source of inefficiency. Despite a substantial increase in the past few years, demand for professionals and contractors still exceeds supply by a large margin. The traditional methods adopted in the Indian construction industry may not suffice the needs of this dynamic environment, as they have produced large inefficiencies. Innovative ways of procurement and project management can satisfy the needs aspired …

Contributors
Nihas, Syed, Kashiwagi, Dean, Sullivan, Kenneth, et al.
Created Date
2013

Within the last decade there has been remarkable interest in single-cell metabolic analysis as a key technology for understanding cellular heterogeneity, disease initiation, progression, and drug resistance. Technologies have been developed for oxygen consumption rate (OCR) measurements using various configurations of microfluidic devices. The technical challenges of current approaches include: (1) deposition of multiple sensors for multi-parameter metabolic measurements, e.g. oxygen, pH, etc.; (2) tedious and labor-intensive microwell array fabrication processes; (3) low yield of hermetic sealing between two rigid fused silica parts, even with a compliance layer of PDMS or Parylene-C. In this thesis, several improved microfabrication technologies are …

Contributors
Song, Ganquan, Meldrum, Deirdre R, Goryll, Michael, et al.
Created Date
2014

Lithium ion batteries have emerged as the most popular energy storage system, but they pose safety issues under extreme temperatures or in the event of a thermal runaway. Lithium ion batteries with inorganic separators offer the advantage of safer operation. An inorganic separator for lithium ion battery was prepared by an improved method of blade coating α-Al2O3 slurry directly on the electrode followed by drying. The improved separator preparation involves a twice-coating process instead of coating the slurry all at once in order to obtain a thin (~40 µm) and uniform coat. It was also found that α-Al2O3 powder with …

Contributors
Sharma, Gaurav Rajpal, Lin, Jerry Y.S., Chan, Candace, et al.
Created Date
2016

Following the success in incorporating perceptual models in audio coding algorithms, their application in other speech/audio processing systems is expanding. In general, all perceptual speech/audio processing algorithms involve minimization of an objective function that directly/indirectly incorporates properties of human perception. This dissertation primarily investigates the problems associated with directly embedding an auditory model in the objective function formulation and proposes possible solutions to overcome high complexity issues for use in real-time speech/audio algorithms. Specific problems addressed in this dissertation include: 1) the development of approximate but computationally efficient auditory model implementations that are consistent with the principles of psychoacoustics, 2) …

Contributors
Krishnamoorthi, Harish, Spanias, Andreas, Papandreou-Suppappola, Antonia, et al.
Created Date
2011

The search for life on Mars is a major NASA priority. A Mars Sample Return (MSR) mission, Mars 2020, will be NASA's next step towards this goal, carrying an instrument suite that can identify samples containing potential biosignatures. Those samples will be later returned to Earth for detailed analysis. This dissertation is intended to inform strategies for fossil biosignature detection in Mars analog samples targeted for their high biosignature preservation potential (BPP) using in situ rover-based instruments. In chapter 2, I assessed the diagenesis and BPP of one relevant analog habitable Martian environment: a playa evaporite sequence within the Verde …

Contributors
Shkolyar, Svetlana, Farmer, Jack, Semken, Steven, et al.
Created Date
2016

As global competition continues to grow more disruptive, organizational change is an ever-present reality that affects companies in all industries at both the operational and strategic level. Organizational change capabilities have become a necessary aspect of existence for organizations in all industries worldwide. Research suggests that more than half of all organizational change efforts fail to achieve their original intended results, with some studies quoting failure rates as high as 70 percent. Exasperating this problem is the fact that no single change methodology has been universally accepted. This thesis examines two aspect of organizational change: the implementation of tactical and …

Contributors
Lines, Brian, Sullivan, Kenneth T, Badger, William, et al.
Created Date
2011

Background – Among influential education reports, there is clear consensus that an expansive range of intrapersonal (e.g. self-regulation) and interpersonal competencies (e.g. empathy) highly influence educational and career success. Research on teaching and learning these competencies is limited in engineering education. Purpose/Hypothesis – This dissertation study explores the impacts of a mindfulness training program on first-year engineering students and aims to understand potential impacts on the development of intrapersonal and interpersonal competencies. Design/Method – A four-session mindfulness-based training program was designed, developed, and facilitated to cultivate intrapersonal and interpersonal competencies. This study employed a multiphase mixed method design in which …

Contributors
Huerta, Mark Vincent, McKenna, Ann, Pipe, Teri, et al.
Created Date
2019

A Cyber Physical System consists of a computer monitoring and controlling physical processes usually in a feedback loop. These systems are increasingly becoming part of our daily life ranging from smart buildings to medical devices to automobiles. The controller comprises discrete software which may be operating in one of the many possible operating modes and interacting with a changing physical environment in a feedback loop. The systems with such a mix of discrete and continuous dynamics are usually termed as hybrid systems. In general, these systems are safety critical, hence their correct operation must be verified. Model Based Design (MBD) …

Contributors
Thekkalore Srinivasa, Rahul, Fainekos, Georgios, Mayyas, Abdel Ra’ouf, et al.
Created Date
2016

Overhead high voltage transmission lines are widely used around the world to deliver power to customers because of their low losses and high transmission capability. Well-coordinated insulation systems are capable of withstanding lightning and switching surge voltages. However, flashover is a serious issue to insulation systems, especially if the insulator is covered by a pollution layer. Many experiments in the laboratory have been conducted to investigate this issue. Since most experiments are time-consuming and costly, good mathematical models could contribute to predicting the insulator flashover performance as well as guide the experiments. This dissertation proposes a new statistical model to …

Contributors
He, Jiahong, Gorur, Ravi, Ayyanar, Raja, et al.
Created Date
2016

This work demonstrates the integration of a wearable particulate detector and a wireless chemical sensor into a single portable system. The detection philosophy of the chemical sensor is based on highly selective and sensitive microfabricated quartz tuning fork arrays and the particle detector detects the particulate level in real-time using a nephelometric (light scattering) approach. The device integration is realized by carefully evaluating the needs of flow rate, power and data collection. Validation test has been carried out in both laboratory and in field trials such as parking structures and highway exits with high and low traffic emissions. The integrated …

Contributors
Gao, Tianle, Tao, Nongjian, Chae, Junseok, et al.
Created Date
2012

When dancers are granted agency over music, as in interactive dance systems, the actors are most often concerned with the problem of creating a staged performance for an audience. However, as is reflected by the above quote, the practice of Argentine tango social dance is most concerned with participants internal experience and their relationship to the broader tango community. In this dissertation I explore creative approaches to enrich the sense of connection, that is, the experience of oneness with a partner and complete immersion in music and dance for Argentine tango dancers by providing agency over musical activities through the …

Contributors
Brown, Courtney Douglass, Paine, Garth, Feisst, Sabine, et al.
Created Date
2017

From the instructional perspective, the scope of "active learning" in the literature is very broad and includes all sorts of classroom activities that engage students with the learning experience. However, classifying all classroom activities as a mode of "active learning" simply ignores the unique cognitive processes associated with the type of activity. The lack of an extensive framework and taxonomy regarding the relative effectiveness of these "active" activities makes it difficult to compare and contrast the value of conditions in different studies in terms of student learning. Recently, Chi (2009) proposed a framework of differentiated overt learning activities (DOLA) as …

Contributors
Menekse, Muhsin, Chi, Michelene T.H., Baker, Dale, et al.
Created Date
2012

There has been a growing emphasis on the education of future generations of engineers who will have to tackle complex, global issues that are sociotechnical in nature. The National Science Foundation invests millions of dollars in interdisciplinary engineering education research (EER) to create an innovative and inclusive culture aimed at radical change in the engineering education system. This exploratory research sought to better understand ways of thinking to address complex educational challenges, specifically, in the context of engineering-social sciences collaborations. The mixed methods inquiry drew on the ways of thinking perspectives from sustainability education to adapt futures, values, systems, and …

Contributors
Dalal, Medha, Archambault, Leanna M, Carberry, Adam, et al.
Created Date
2019

Hypoxia is a pathophysiological condition which results from lack of oxygen supply in tumors. The assessment of tumor hypoxia and its response to therapies can provide guidelines for optimization and personalization of therapeutic protocols for better treatment. Previous research has shown the difficulty in measuring hypoxia anatomically due to its heterogenous nature. This makes the study of hypoxia through various imaging modalities and mapping techniques crucial. The potential of hypoxia targeting T1 contrast agent GdDO3NI in generating hypoxia maps has been studied earlier. In this work, the similarities between hypoxia maps generated by MRI using GdDO3NI and pimonidazole based immunohistochemistry …

Contributors
Sahu, Sulagna, Kodibagkar, Vikram D., Sadleir, Rosalind, et al.
Created Date
2018

Switching surges are a common type of phenomenon that occur on any sort of power system network. These are more pronounced on long transmission lines and in high voltage substations. The problem with switching surges is encountered when a lot of power is transmitted across a transmission line/network, typically from a concentrated generation node to a concentrated load. The problem becomes significantly worse when the transmission line is long and when the voltage levels are high, typically above 400 kV. These overvoltage transients occur following any type of switching action such as breaker operation, fault occurrence/clearance and energization, and they …

Contributors
Shaikh, Mohammed Mubashir, Qin, Jiangchao, Heydt, Gerald T, et al.
Created Date
2018

The demand for miniaturized components with feature sizes as small as tens of microns and tolerances as small as 0.1 microns is on the rise in the fields of aerospace, electronics, optics and biomedical engineering. Micromilling has proven to be a process capable of generating the required accuracy for these features and is an alternative to various non-mechanical micro-manufacturing processes which are limited in terms of cost and productivity, especially at the micro-meso scale. The micromilling process is on the surface, a miniaturized version of conventional milling, hence inheriting its benefits. However, the reduction in scale by a few magnitudes …

Contributors
Bajaj, Anuj Kishorkumar, Sodemann, Angela A, Bekki, Jeniffer, et al.
Created Date
2015

Just for a moment! Imagine you live in Arizona without air-conditioning systems! Air-conditioning and refrigeration systems are one of the most crucial systems in anyone’s house and car these days. Energy resources are becoming more scarce and expensive. Most of the currently used refrigerants have brought an international concern about global warming. The search for more efficient cooling/refrigeration systems with environmental friendly refrigerants has become more and more important so as to reduce greenhouse gas emissions and ensure sustainable and affordable energy systems. The most widely used air-conditioning and refrigeration system, based on the vapor compression cycle, is driven by …

Contributors
ALELYANI, Sami Mohammed, Phelan, Patrick E, Wang, Liping, et al.
Created Date
2018

This thesis discusses the evolution of conduction mechanism in the silver (Ag) on zinc oxide (ZnO) thin film system with respect to the Ag morphology. As a plausible substitute for indium tin oxide (ITO), TCO/Metal/TCO (TMT) structure has received a lot of attentions as a prospective ITO substitute due to its low resistivity and desirable transmittance. However, the detailed conduction mechanism is not fully understood. In an attempt to investigate the conduction mechanism of the ZnO/Ag/ZnO thin film system with respect to the Ag microstructure, the top ZnO layer is removed, which offers a better view of Ag morphology by …

Contributors
Zhang, Shengke, Alford, Terry L, Schroder, Dieter K, et al.
Created Date
2012

Nanoporous materials, with pore sizes less than one nanometer, have been incorporated as filler materials into state-of-the-art polyamide-based thin-film composite membranes to create thin-film nanocomposite (TFN) membranes for reverse osmosis (RO) desalination. However, these TFN membranes have inconsistent changes in desalination performance as a result of filler incorporation. The nano-sized filler’s transport role for enhancing water permeability is unknown: specifically, there is debate around the individual transport contributions of the polymer, nanoporous particle, and polymer/particle interface. Limited studies exist on the pressure-driven water transport mechanism through nanoporous single-crystal nanoparticles. An understanding of the nanoporous particles water transport role in TFN …

Contributors
Cay Durgun, Pinar, Lind, Mary Laura, Lin, Jerry Y. S., et al.
Created Date
2018

ABSTRACT There has been plenty written on the topic of process management in business. This study focuses more on the need to research and develop a model to establish "balance" in process. Reengineering process and investing capital into current technology does not improve the outcome of process alone. The actual process activity coupled with human interface combined with technology determines the outcome of processes, however they do not indicate whether it is a balanced process or not. Wherein the word balance really means sustainable for long periods of time and easily reproduced by others. This study argues for the need …

Contributors
Jeffers, Anthony Alan, Sullivan, Kenneth, Badger, Bill, et al.
Created Date
2012

The use of electromyography (EMG) signals to characterize muscle fatigue has been widely accepted. Initial work on characterizing muscle fatigue during isometric contractions demonstrated that its frequency decreases while its amplitude increases with the onset of fatigue. More recent work concentrated on developing techniques to characterize dynamic contractions for use in clinical and training applications. Studies demonstrated that as fatigue progresses, the EMG signal undergoes a shift in frequency, and different physiological mechanisms on the possible cause of the shift were considered. Time-frequency processing, using the Wigner distribution or spectrogram, is one of the techniques used to estimate the instantaneous …

Contributors
Austin, Hiroko, Papandreou-Suppappola, Antonia, Kovvali, Narayan, et al.
Created Date
2012

Alkali-activated aluminosilicates, commonly known as "geopolymers", are being increasingly studied as a potential replacement for Portland cement. These binders use an alkaline activator, typically alkali silicates, alkali hydroxides or a combination of both along with a silica-and-alumina rich material, such as fly ash or slag, to form a final product with properties comparable to or better than those of ordinary Portland cement. The kinetics of alkali activation is highly dependent on the chemical composition of the binder material and the activator concentration. The influence of binder composition (slag, fly ash or both), different levels of alkalinity, expressed using the ratios …

Contributors
Chithiraputhiran, Sundara Raman, Neithalath, Narayanan, Rajan, Subramaniyam D, et al.
Created Date
2012

ABSTRACT Facility managers have an important job in today's competitive business world by caring for the backbone of the corporation's capital. Maintaining assets and the support efforts cause facility managers to fight an uphill battle to prove the worth of their organizations. This thesis will discuss the important and flexible use of measurement and leadership reports and the benefits of justifying the work required to maintain or upgrade a facility. The task is streamlined by invoking accountability to subject experts. The facility manager must trust in the ability of his or her work force to get the job done. However, …

Contributors
Tellefsen, Thor, Sullivan, Kenneth, Kashiwagi, Dean, et al.
Created Date
2011

The U.S. Army Medical Command has been testing a leadership based structure to increase the performance of delivering construction and facility services in its system of $600M of construction and 26 major hospital facilities in the U.S. The organizational requirement was to minimize the management and oversight of contractors and simultaneously increase project performance. The research proposes that a leadership based structure can supplement the perception, preplanning, and risk minimization capability of a contractor's project manager, thus increasing the project performance (on time, within budget, and meeting expectations) and decreasing client management requirement. The projects were delivered in a best …

Contributors
Malhotra, Neha, Kashiwagi, Dean T, Sullivan, Kenneth, et al.
Created Date
2010

With growing concern regarding environmental issues and the need for a more sustainable grid, power systems have seen a fast expansion of renewable resources in the last decade. The uncertainty and variability of renewable resources has posed new challenges on system operators. Due to its energy-shifting and fast-ramping capabilities, energy storage (ES) has been considered as an attractive solution to alleviate the increased renewable uncertainty and variability. In this dissertation, stochastic optimization is utilized to evaluate the benefit of bulk energy storage to facilitate the integration of high levels of renewable resources in transmission systems. A cost-benefit analysis is performed …

Contributors
Li, Nan, Hedman, Kory W, Tylavksy, Daniel J, et al.
Created Date
2016

One of the most remarkable outcomes resulting from the evolution of the web into Web 2.0, has been the propelling of blogging into a widely adopted and globally accepted phenomenon. While the unprecedented growth of the Blogosphere has added diversity and enriched the media, it has also added complexity. To cope with the relentless expansion, many enthusiastic bloggers have embarked on voluntarily writing, tagging, labeling, and cataloguing their posts in hopes of reaching the widest possible audience. Unbeknown to them, this reaching-for-others process triggers the generation of a new kind of collective wisdom, a result of shared collaboration, and the …

Contributors
Galan, Magdiel Francisco, Liu, Huan, Davulcu, Hasan, et al.
Created Date
2015

Determining the thermal conductivity of carbon gas diffusion layers used in hydrogen fuel cells is a very active topic of research. The primary driver behind this research is due to the need for development of proton exchange membrane fuels with longer usable life cycles before failure. As heat is a byproduct of the oxygen-hydrogen reaction an optimized pathway to remove the excess heat is needed to prevent thermal damage to the fuel cell as both mechanical and chemical degradation is accelerated under elevated temperatures. Commercial systems used for testing thermal conductivity are readily available, but are prohibitively expensive, ranging from …

Contributors
Sucher, Brent, Kannan, Arunachala, Hsu, Keng, et al.
Created Date
2016

In this thesis, an approach to develop low-frequency accelerometer based on molecular electronic transducers (MET) in an electrochemical cell is presented. Molecular electronic transducers are a class of inertial sensors which are based on an electrochemical mechanism. Motion sensors based on MET technology consist of an electrochemical cell that can be used to detect the movement of liquid electrolyte between electrodes by converting it to an output current. Seismometers based on MET technology are attractive for planetary applications due to their high sensitivity, low noise, small size and independence on the direction of sensitivity axis. In addition, the fact that …

Contributors
Zhao, Zuofeng, Yu, Hongyu, Zhang, Junshan, et al.
Created Date
2015