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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 applications utilizing nanoparticles have grown in both industrial and academic areas because of the very large surface area to volume ratios of these particles. One of the best ways to process and control these nanoparticles is fluidization. In this work, a new microjet and vibration assisted (MVA) fluidized bed system was developed in order to fluidize nanoparticles. The system was tested and the parameters optimized using two commercially available TiO2 nanoparticles: P25 and P90. The fluidization quality was assessed by determining the non-dimensional bed height as well as the non-dimensional pressure drop. The non-dimensional bed height for the nanosized …

Contributors
an, keju, Andino, Jean, Phelan, Patrick, et al.
Created Date
2019

Two-dimensional transition metal dichalcogenides (TMDCs) such as molybdenum disulfide (MoS2), tungsten disulfide (WS2), molybdenum diselenide (MoSe2) and tungsten diselenide (WSe2) are attractive for use in biotechnology, optical and electronics devices due to their promising and tunable electrical, optical and chemical properties. To fulfill the variety of requirements for different applications, chemical treatment methods are developed to tune their properties. In this dissertation, plasma treatment, chemical doping and functionalization methods have been applied to tune the properties of TMDCs. First, plasma treatment of TMDCs results in doping and generation of defects, as well as the synthesis of transition metal oxides (TMOs) …

Contributors
Chu, Ximo, Wang, Qing Hua, Sieradzki, Karl, et al.
Created Date
2018

In this work, the development of a novel and a truly in-shoe force measurement system is reported. The device consists of a shoe insole with six thin film piezoresistive sensors and the main circuit board. The piezoresistive sensors are used for the measurement of plantar pressure during daily human activities. The motion sensor mounted on the main circuit board captures kinematic data. In addition, the main circuit board is responsible for the wireless transmission of the data from all the sensors in real-time using BLE protocol. It is housed within the midsole of the shoe, under the medial arch of …

Contributors
Badarinath, Abhishek, Kiaei, Sayfe, Bakkaloglu, Bertan, et al.
Created Date
2018

Technology advancements in diagnostic imaging, smart sensing, and health information systems have resulted in a data-rich environment in health care, which offers a great opportunity for Precision Medicine. The objective of my research is to develop data fusion and system informatics approaches for quality and performance improvement of health care. In my dissertation, I focus on three emerging problems in health care and develop novel statistical models and machine learning algorithms to tackle these problems from diagnosis to care to system-level decision-making. The first topic is diagnosis/subtyping of migraine to customize effective treatment to different subtypes of patients. Existing clinical …

Contributors
Si, Bing, Li, Jing, Montgomery, Douglas, et al.
Created Date
2018

Microbial fuel cells(MFC) use micro-organisms called anode-respiring bacteria(ARB) to convert chemical energy into electrical energy. This process can not only treat wastewater but can also produce useful byproduct hydrogen peroxide(H2O2). Process variables like anode potential and pH play important role in the MFC operation and the focus of this dissertation are pH and potential control problems. Most of the adaptive pH control solutions use signal-based-norms as cost functions, but their strong dependency on excitation signal properties makes them sensitive to noise, disturbances, and modeling errors. System-based-norm( H-infinity) cost functions provide a viable alternative for the adaptation as they are less …

Contributors
Joshi, Rakesh, Tsakalis, Konstantinos, Rodriguez, Armando, et al.
Created Date
2018

The 21st-century professional or knowledge worker spends much of the working day engaging others through electronic communication. The modes of communication available to knowledge workers have rapidly increased due to computerized technology advances: conference and video calls, instant messaging, e-mail, social media, podcasts, audio books, webinars, and much more. Professionals who think for a living express feelings of stress about their ability to respond and fear missing critical tasks or information as they attempt to wade through all the electronic communication that floods their inboxes. Although many electronic communication tools compete for the attention of the contemporary knowledge worker, most …

Contributors
Counts, Virginia, Parrish, Kristen, Allenby, Braden, et al.
Created Date
2018

Increasing density of microelectronic packages, results in an increase in thermal and mechanical stresses within the various layers of the package. To accommodate the high-performance demands, the materials used in the electronic package would also require improvement. Specifically, the damage that often occurs in solders that function as die-attachment and thermal interfaces need to be addressed. This work evaluates and characterizes thermo-mechanical damage in two material systems – Electroplated Tin and Sintered Nano-Silver solder. Tin plated electrical contacts are prone to formation of single crystalline tin whiskers which can cause short circuiting. A mechanistic model of their formation, evolution and …

Contributors
Lujan Regalado, Irene, Chawla, Nikhilesh, Frear, Darrel, et al.
Created Date
2018

Concrete is relatively brittle, and its tensile strength is typically only about one-tenth of its compressive strength. Regular concrete is therefore normally uses reinforcement steel bars to increase the tensile strength. It is becoming increasingly popular to use random distributed fibers as reinforcement and polymeric fibers is once such kind. In the case of polymeric fibers, due to hydrophobicity and lack of any chemical bond between the fiber and matrix, the weak interface zone limits the ability of the fibers to effectively carry the load that is on the matrix phase. Depending on the fiber’s surface asperity, shape, chemical nature, …

Contributors
Tiwari, Sanchay Sushil, Mobasher, Barzin, Neithalath, Narayanan, et al.
Created Date
2018

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

Commercial Li-ion cells (18650: Li4Ti5O12 anodes and LiCoO2 cathodes) were subjected to simulated Electric Vehicle (EV) conditions using various driving patterns such as aggressive driving, highway driving, air conditioning load, and normal city driving. The particular drive schedules originated from the Environment Protection Agency (EPA), including the SC-03, UDDS, HWFET, US-06 drive schedules, respectively. These drive schedules have been combined into a custom drive cycle, named the AZ-01 drive schedule, designed to simulate a typical commute in the state of Arizona. The battery cell cycling is conducted at various temperature settings (0, 25, 40, and 50 °C). At 50 °C, …

Contributors
Abdelhay, Reem, Kannan, Arunachala Mada, Wishart, Jeffrey, et al.
Created Date
2018

Encapsulant is a key packaging component of photovoltaic (PV) modules, which protects the solar cell from physical, environmental and electrical damages. Ethylene-vinyl acetate (EVA) is one of the major encapsulant materials used in the PV industry. This work focuses on indoor accelerated ultraviolet (UV) stress testing and characterization to investigate the EVA discoloration and delamination in PV modules by using various non-destructive characterization techniques, including current-voltage (IV) measurements, UV fluorescence (UVf) and colorimetry measurements. Mini-modules with glass/EVA/cell/EVA/backsheet construction were fabricated in the laboratory with two types of EVA, UV-cut EVA (UVC) and UV-pass EVA (UVP). The accelerated UV testing was …

Contributors
Dolia, Kshitiz, Tamizhmani, Govindasamy, Green, Matthew, et al.
Created Date
2018

This work presents the integration of user intent detection and control in the development of the fluid-driven, wearable, and continuum, Soft Poly-Limb (SPL). The SPL utilizes the numerous traits of soft robotics to enable a novel approach to provide safe and compliant mobile manipulation assistance to healthy and impaired users. This wearable system equips the user with an additional limb made of soft materials that can be controlled to produce complex three-dimensional motion in space, like its biological counterparts with hydrostatic muscles. Similar to the elephant trunk, the SPL is able to manipulate objects using various end effectors, such as …

Contributors
Vale, Nicholas Marshall, Polygerinos, Panagiotis, Zhang, Wenlong, et al.
Created Date
2018

Digital imaging and image processing technologies have revolutionized the way in which we capture, store, receive, view, utilize, and share images. In image-based applications, through different processing stages (e.g., acquisition, compression, and transmission), images are subjected to different types of distortions which degrade their visual quality. Image Quality Assessment (IQA) attempts to use computational models to automatically evaluate and estimate the image quality in accordance with subjective evaluations. Moreover, with the fast development of computer vision techniques, it is important in practice to extract and understand the information contained in blurred images or regions. The work in this dissertation focuses …

Contributors
Golestaneh, Seyedalireza, Karam, Lina, Bliss, Daniel W., et al.
Created Date
2018

Recent studies have identified that contractors in the Saudi construction industry are not the main party that cause risks as owners and other parties have the major share of causing risks. However, with the identification that risks out of contractors’ control are a leading cause of low performance, there is a lack of efficient risk mitigation practices in Saudi to manage these risks. The main aim of this dissertation is to assess the current practices applied by contractors to minimize risk out of their control and develop a risk mitigation model to manage these risks. The main objectives of the …

Contributors
Algahtany, Mohammed, Sullivan, Kenneth, Kashiwagi, Dean, et al.
Created Date
2018

Asphalt concrete is the most recycled material in the United States and its reclamation allows the positive reuse of the constituent aggregates and asphalt binder, contributing to the long-term sustainability of the transportation infrastructure; decreasing costs, and the total energy and greenhouse emissions embodied into new materials and infrastructure. Although the national trends in Reclaimed Asphalt Pavements (RAP) usage are encouraging, the environmental conditions in Phoenix, Arizona are extreme and needs further consideration. The objective of this research study was to evaluate the viability of using RAP in future pavement maintenance and rehabilitation projects for the City. Agencies in the …

Contributors
ARREDONDO, GONZALO ZELADA, Kaloush, Kamil E., Mamlouk, Michael, et al.
Created Date
2018

Healthcare operations have enjoyed reduced costs, improved patient safety, and innovation in healthcare policy over a huge variety of applications by tackling prob- lems via the creation and optimization of descriptive mathematical models to guide decision-making. Despite these accomplishments, models are stylized representations of real-world applications, reliant on accurate estimations from historical data to jus- tify their underlying assumptions. To protect against unreliable estimations which can adversely affect the decisions generated from applications dependent on fully- realized models, techniques that are robust against misspecications are utilized while still making use of incoming data for learning. Hence, new robust techniques are …

Contributors
Bren, Austin, Saghafian, Soroush, Mirchandani, Pitu, et al.
Created Date
2018

Energy production is driven by economic needs, which sometimes results in the environment and wildlife being an afterthought. Unfortunately, many animals are killed as a result of flying too close to wind turbines, and the addition of animal deterrent devices are a promising alternative. This thesis seeks to provide a solution as a part of post- construction considerations regarding wildlife and wind turbine interactions through the introduction of a blade mounted ecological device. After testing the hypothesis, the data revealed the device is effective for increasing power output when placed at the root, middle, and tip of the blade. The …

Contributors
Booth, Stephanie, Trimble, Steven, Middleton, James, et al.
Created Date
2018

The sensor industry is a growing industry that has been predicted by Allied Market Research to be a multi-billion industry by 2022. One of the many key drives behind this rapid growth in the sensor industry is the increase incorporation of sensors into portable electrical devices. The value for sensor technologies are increased when the sensors are developed into innovative measuring system for application uses in the Aerospace, Defense, and Healthcare industries. While sensors are not new, their increased performance, size reduction, and decrease in cost has opened the door for innovative sensor combination for portable devices that could be …

Contributors
Nichols, Kevin William, Redkar, Sangram, Rogers, Brad, et al.
Created Date
2018

In this dissertation, three complex material systems including a novel class of hyperuniform composite materials, cellularized collagen gel and low melting point alloy (LMPA) composite are investigated, using statistical pattern characterization, stochastic microstructure reconstruction and micromechanical analysis. In Chapter 1, an introduction of this report is provided, in which a brief review is made about these three material systems. In Chapter 2, detailed discussion of the statistical morphological descriptors and a stochastic optimization approach for microstructure reconstruction is presented. In Chapter 3, the lattice particle method for micromechanical analysis of complex heterogeneous materials is introduced. In Chapter 4, a new …

Contributors
Xu, Yaopengxiao, Jiao, Yang, Liu, Yongming, et al.
Created Date
2018

Recent research and study have showed the potential of auto-parametric system in controlling stability and parametric resonance. In this project, two different designs for auto-parametrically excited mass-spring-damper systems were studied. The theoretical models were developed to describe the behavior of the systems, and simulation models were constructed to validate the analytical results. The error between simulation and theoretical results was within 2%. Both theoretical and simulation results showed that the implementation of auto-parametric system could help reduce or amplify the resonance significantly. Dissertation/Thesis

Contributors
Le, Thao, Redkar, Sangram, Sugar, Thomas, et al.
Created Date
2018

The increase in computing power has simultaneously increased the demand for input/output (I/O) bandwidth. Unfortunately, the speed of I/O and memory interconnects have not kept pace. Thus, processor-based systems are I/O and interconnect limited. The memory aggregated bandwidth is not scaling fast enough to keep up with increasing bandwidth demands. The term "memory wall" has been coined to describe this phenomenon. A new memory bus concept that has the potential to push double data rate (DDR) memory speed to 30 Gbit/s is presented. We propose to map the conventional DDR bus to a microwave link using a multicarrier frequency division …

Contributors
Bensalem, Brahim, Aberle, James T., Bakkaloglu, Bertan, et al.
Created Date
2018

The human hand comprises complex sensorimotor functions that can be impaired by neurological diseases and traumatic injuries. Effective rehabilitation can bring the impaired hand back to a functional state because of the plasticity of the central nervous system to relearn and remodel the lost synapses in the brain. Current rehabilitation therapies focus on strengthening motor skills, such as grasping, employ multiple objects of varying stiffness and devices that are bulky, costly, and have limited range of stiffness due to the rigid mechanisms employed in their variable stiffness actuators. This research project presents a portable cost-effective soft robotic haptic device with …

Contributors
Sebastian, Frederick, Polygerinos, Panagiotis, Santello, Marco, et al.
Created Date
2018

Alloying in semiconductors has enabled many civilian technologies in optoelectronic, photonic fields and more. While the phenomenon of alloying is well established in traditional bulk semiconductors, owing to vastly available ternary phase diagrams, the ability to alloy in 2D systems are less clear. Recently anisotropic materials such as ReS2 and TiS3 have been extensively studied due to their direct-gap semiconductor and high mobility behaviors. This work is a report on alloys of ReS2 & ReSe2 and TiS3 &TiSe3. Alloying selenium into ReS2 in the creation of ReS2xSe2-x, tunes the band gap and changes its vibrational spectrum. Depositing this alloy using …

Contributors
Agarwal, Ashutosh, Tongay, Sefaattin, Green, Matthew, et al.
Created Date
2018

Today, we use resources faster than they can be replaced. Construction consumes more resources than any other industry and has one of the largest waste streams. Resource consumption and waste generation are expected to grow as the global population increases. The circular economy (CE) is based on the concept of a closed-loop cycle (CLC) and proposes a solution that, in theory, can eliminate the environmental impacts caused by construction and demolition (C&D) waste and increase the efficiency of resources’ use. In a CLC, building materials are reused, remanufactured, recycled, and reintegrated into other buildings (or into other sectors) without creating …

Contributors
Campos da Cruz Rios, Fernanda, Grau, David, Chong, Oswald, et al.
Created Date
2018

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

Learning from the anatomy of leaves, a new approach to bio-inspired passive evaporative cooling is presented that utilizes the temperature-responsive properties of PNIPAm hydrogels. Specifically, an experimental evaporation rate from the polymer, PNIPAm, is determined within an environmental chamber, which is programmed to simulate temperature and humidity conditions common in Phoenix, Arizona in the summer. This evaporation rate is then used to determine the theoretical heat transfer through a layer of PNIPAm that is attached to an exterior wall of a building within a ventilated cavity in Phoenix. The evaporation of water to the air gap from the polymer layer …

Contributors
Bradford, Katherine, Reddy, T A, Bryan, Harvey, et al.
Created Date
2018

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

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

Flame retardants (FRs) are applied to variety of consumer products such as textiles and polymers for fire prevention and fire safety. Substantial research is ongoing to replace traditional FRs with alternative materials that are less toxic, present higher flame retardancy and result in lower overall exposure as there are potential health concerns in case of exposure to popular FRs. Carbonaceous nanomaterials (CNMs) such as carbon nanotubes (CNTs) and graphene oxide (GO) have been studied and applied to polymer composites and electronics extensively due to their remarkable properties. Hence CNMs are considered as potential alternative materials that present high flame retardancy. …

Contributors
Nosaka, Takayuki, Herckes, Pierre, Westerhoff, Paul, et al.
Created Date
2018

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

Recently, two-dimensional (2D) materials have emerged as a new class of materials with highly attractive electronic, optical, magnetic, and thermal properties. However, there exists a sub-category of 2D layers wherein constituent metal atoms are arranged in a way that they form weakly coupled chains confined in the 2D landscape. These weakly coupled chains extend along particular lattice directions and host highly attractive properties including high thermal conduction pathways, high-mobility carriers, and polarized excitons. In a sense, these materials offer a bridge between traditional one-dimensional (1D) materials (nanowires and nanotubes) and 2D layered systems. Therefore, they are often referred as pseudo-1D …

Contributors
Wu, Kedi, Tongay, Sefaattin, Zhuang, Houlong, et al.
Created Date
2018

Reinforcement learning (RL) is a powerful methodology for teaching autonomous agents complex behaviors and skills. A critical component in most RL algorithms is the reward function -- a mathematical function that provides numerical estimates for desirable and undesirable states. Typically, the reward function must be hand-designed by a human expert and, as a result, the scope of a robot's autonomy and ability to safely explore and learn in new and unforeseen environments is constrained by the specifics of the designed reward function. In this thesis, I design and implement a stateful collision anticipation model with powerful predictive capability based upon …

Contributors
Richardson, Trevor W, Ben Amor, Heni, Yang, Yezhou, et al.
Created Date
2018

With the growing penetration of plug-in electric vehicles (PEVs), the impact of the PEV charging brought to the utility grid draws more and more attention. This thesis focused on the optimization of a home energy management system (HEMS) with the presence of PEVs. For a household microgrid with photovoltaic (PV) panels and PEVs, a HEMS using model predictive control (MPC) is designed to achieve the optimal PEV charging. Soft electric loads and an energy storage system (ESS) are also considered in the optimization of PEV charging in the MPC framework. The MPC is solved through mixed-integer linear programming (MILP) by …

Contributors
Zhao, Yue, Chen, Yan, Johnson, Nathan, et al.
Created Date
2018

The concept of the microgrid is widely studied and explored in both academic and industrial societies. The microgrid is a power system with distributed generations and loads, which is intentionally planned and can be disconnected from the main utility grid. Nowadays, various distributed power generations (wind resource, photovoltaic resource, etc.) are emerging to be significant power sources of the microgrid. This thesis focuses on the system structure of Photovoltaics (PV)-dominated microgrid, precisely modeling and stability analysis of the specific system. The grid-connected mode microgrid is considered, and system control objectives are: PV panel is working at the maximum power point …

Contributors
Xu, Hongru, Chen, Yan, Johnson, Nathan, et al.
Created Date
2018

Measurements of the response of superconducting nanowire single photon detector (SNSPD) devices to changes in various forms of input power can be used for characterization of the devices and for probing device-level physics. Two niobium nitride (NbN) superconducting nanowires developed for use as SNSPD devices are embedded as the inductive (L) component in resonant inductor/capacitor (LC) circuits coupled to a microwave transmission line. The capacitors are low loss commercial chip capacitors which limit the internal quality factor of the resonators to approximately $Qi = 170$. The resonator quality factor, approximately $Qr = 23$, is dominated by the coupling to the …

Contributors
Schroeder, Edward Ralph Aaron, Mauskopf, Philip, Chamberlin, Ralph, et al.
Created Date
2018

Phase change materials (PCMs) are combined sensible-and-latent thermal energy storage materials that can be used to store and dissipate energy in the form of heat. PCMs incorporated into wall-element systems have been well-studied with respect to energy efficiency of building envelopes. New applications of PCMs in infrastructural concrete, e.g., for mitigating early-age cracking and freeze-and-thaw induced damage, have also been proposed. Hence, the focus of this dissertation is to develop a detailed understanding of the physic-chemical and thermo-mechanical characteristics of cementitious systems and novel coating systems for wall-elements containing PCM. The initial phase of this work assesses the influence of …

Contributors
Aguayo, Matthew Joseph, Neithalath, Narayanan, Rajan, Subramaniam, et al.
Created Date
2018

Over the past several decades, there has been a growing interest in the use of fluorescent probes in low-cost diagnostic devices for resource-limited environments. This dissertation details the design, development, and deployment of an inexpensive, multiplexed, and quantitative, fluorescence-based lateral flow immunoassay platform, in light of the specific constraints associated with resource-limited settings. This effort grew out of the need to develop a highly sensitive, field-deployable platform to be used as a primary screening and early detection tool for serologic biomarkers for the high-risk human papillomavirus (hrHPV) infection. A hrHPV infection is a precursor for developing high-grade cervical intraepithelial neoplasia …

Contributors
Obahiagbon, Uwadiae, Blain Christen, Jennifer M, Anderson, Karen S, et al.
Created Date
2018

Global photovoltaic (PV) module installation in 2018 is estimated to exceed 100 GW, and crystalline Si (c-Si) solar cell-based modules have a share more than 90% of the global PV market. To reduce the social cost of PV electricity, further developments in reliability of solar panels are expected. These will lead to realize longer module lifetime and reduced levelized cost of energy. As many as 86 failure modes are observed in PV modules [1] and series resistance increase is one of the major durability issues of all. Series resistance constitutes emitter sheet resistance, metal-semiconductor contact resistance, and resistance across the …

Contributors
Buddha, viswa sai pavan, Tamizhmani, Govindasamy, Alford, Terry, et al.
Created Date
2018

In this project, current-voltage (I-V) and Deep Level Transient Spectroscopy (DLTS) measurements are used to (a) characterize the electrical properties of Nb/p-type Si Schottky barriers, (b) identify the concentration and physical character of the electrically active defects present in the depletion region, and (c) use thermal processing to reduce the concentration or eliminate the defects. Barrier height determinations using temperature-dependent I-V measurements indicate that the barrier height decreases from 0.50 eV to 0.48 eV for anneals above 200 C. The electrically-active defect concentration measured using DLTS (deep level transient spectroscopy) drops markedly after anneals at 250 C. A significant increase …

Contributors
Krishna Murthy, Madhu, Newman, Nathan, Goryll, Michael, et al.
Created Date
2018

Robotic swarms can potentially perform complicated tasks such as exploration and mapping at large space and time scales in a parallel and robust fashion. This thesis presents strategies for mapping environmental features of interest – specifically obstacles, collision-free paths, generating a metric map and estimating scalar density fields– in an unknown domain using data obtained by a swarm of resource-constrained robots. First, an approach was developed for mapping a single obstacle using a swarm of point-mass robots with both directed and random motion. The swarm population dynamics are modeled by a set of advection-diffusion-reaction partial differential equations (PDEs) in which …

Contributors
Ramachandran, Ragesh Kumar, Berman, Spring M, Mignolet, Marc, et al.
Created Date
2018

Nanolaminate materials are layered composites with layer thickness ≤ 100 nm. They exhibit unique properties due to their small length scale, the presence of a high number of interfaces and the effect of imposed constraint. This thesis focuses on the mechanical behavior of Al/SiC nanolaminates. The high strength of ceramics combined with the ductility of Al makes this combination desirable. Al/SiC nanolaminates were synthesized through magnetron sputtering and have an overall thickness of ~ 20 μm which limits the characterization techniques to microscale testing methods. A large amount of work has already been done towards evaluating their mechanical properties under …

Contributors
Singh, Somya, Chawla, Nikhilesh, Neithalath, Narayanan, et al.
Created Date
2018

Across a wide variety of sports, our visual abilities have been proven to profoundly impact performance. Numerous studies have examined the effects of visual training in athletes and have found supporting evidence that performance can be enhanced through vision training. The present case study aimed to expand on research in the field of stroboscopic visual training. To do so, twelve softball players, half novice and half expert, took part in this study. Six underwent a four-week stroboscopic training program and six underwent a four-week non-stroboscopic training program. The quantitative data collected in this case study showed that training group (stroboscopic …

Contributors
Edgerton, Lindsey Ann, Gray, Robert, Branaghan, Russ, et al.
Created Date
2018

Future autonomous vehicle systems will be diverse in design and functionality since they will be produced by different brands. In the automotive industry, trustworthiness of a vehicle is closely tied to its perceived safety. Trust involves dependence on another agent in an uncertain situation. Perceptions of system safety, trustworthiness, and performance are important because they guide people’s behavior towards automation. Specifically, these perceptions impact how reliant people believe they can be on the system to do a certain task. Over or under reliance can be a concern for safety because they involve the person allocating tasks between themselves and the …

Contributors
Celmer, Natalie, Branaghan, Russell, Chiou, Erin, et al.
Created Date
2018

Laser radars or lidar’s have been used extensively to remotely study winds within the atmospheric boundary layer and atmospheric transport. Lidar sensors have become an important tool within the meteorology and the wind energy community. For example, Doppler lidars are used frequently in wind resource assessment, wind turbine control as well as in atmospheric science research. A Time of Flight based (ToF) direct detection lidar sensor is used in vehicles to navigate through complex and dynamic environments autonomously. These optical sensors are used to map the environment around the car accurately for perception and localization tasks that help achieve complete …

Contributors
Bhaskaran, Sreevatsan, Calhoun, Ronald J, Dahm, Werner, et al.
Created Date
2018

Buildings continue to take up a significant portion of the global energy consumption, meaning there are significant research opportunities in reducing the energy consumption of the building sector. One widely studied area is waste heat recovery. The purpose of this research is to test a prototype thermogalvanic cell in the form factor of a UK metric brick sized at 215 mm × 102.5 mm × 65 mm for the experimental power output using a copper/copper(II) (Cu/Cu2+) based aqueous electrode. In this study the thermogalvanic brick uses a 0.7 M CuSO4 + 0.1 M H2SO4 aqueous electrolyte with copper electrodes as …

Contributors
Lee, William J, Phelan, Patrick, El Asmar, Mounir, et al.
Created Date
2018

Expansive clay soils, when subjected to substantial moisture change, can be extremely problematic causing various types of damage to lightly-loaded structures. Solving these problems requires an understanding of unsaturated soil mechanics. Soil suction, related to moisture content change, is important in the development of unsaturated soil properties and in the assessment of initial and final stress for heave computation. Direct measurement of soil suction on expansive clays to determine field suction profiles is quite limited due primarily to tradition and cost-driven geotechnical field investigation practices prioritizing water content measurement over soil suction measurement. This study employs a surrogate to estimate …

Contributors
Cuzme, Alan, Houston, Sandra, Zapata, Claudia, 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

Recent technology advancements in photovoltaics have enabled crystalline silicon (c-Si) solar cells to establish outstanding photoconversion efficiency records. Remarkable progresses in research and development have been made both on the silicon feedstock quality as well as the technology required for surface passivation, the two dominant sources of performance loss via recombination of photo-generated charge carriers within advanced solar cell architectures. As these two aspects of the solar cell framework improve, the need for a thorough analysis of their respective contribution under varying operation conditions has emerged along with challenges related to the lack of sensitivity of available characterization techniques. The …

Contributors
Bernardini, Simone, Bertoni, Mariana I, Coletti, Gianluca, et al.
Created Date
2018

Hardware implementation of deep neural networks is earning significant importance nowadays. Deep neural networks are mathematical models that use learning algorithms inspired by the brain. Numerous deep learning algorithms such as multi-layer perceptrons (MLP) have demonstrated human-level recognition accuracy in image and speech classification tasks. Multiple layers of processing elements called neurons with several connections between them called synapses are used to build these networks. Hence, it involves operations that exhibit a high level of parallelism making it computationally and memory intensive. Constrained by computing resources and memory, most of the applications require a neural network which utilizes less energy. …

Contributors
Kolala Venkataramanaiah, Shreyas, Seo, Jae-sun, chakrabarti, Chaitali, et al.
Created Date
2018

This paper describes an effort to bring wing structural stiffness and aeroelastic considerations early in the conceptual design process with an automated tool. Stiffness and aeroelasticity can be well represented with a stochastic model during conceptual design because of the high level of uncertainty and variability in wing non-structural mass such as fuel loading and control surfaces. To accomplish this, an improvement is made to existing design tools utilizing rule based automated design to generate wing torque box geometry from a specific wing outer mold-line. Simple analysis on deflection and inferred stiffness shows how early conceptual design choices can strongly …

Contributors
Miskin, Daniel L, Takahashi, Timothy T, Mignolet, Marc, et al.
Created Date
2018