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One of the challenges in future semiconductor device design is excessive rise of power dissipation and device temperatures. With the introduction of new geometrically confined device structures like SOI, FinFET, nanowires and continuous incorporation of new materials with poor thermal conductivities in the device active region, the device thermal problem

One of the challenges in future semiconductor device design is excessive rise of power dissipation and device temperatures. With the introduction of new geometrically confined device structures like SOI, FinFET, nanowires and continuous incorporation of new materials with poor thermal conductivities in the device active region, the device thermal problem is expected to become more challenging in coming years. This work examines the degradation in the ON-current due to self-heating effects in 10 nm channel length silicon nanowire transistors. As part of this dissertation, a 3D electrothermal device simulator is developed that self-consistently solves electron Boltzmann transport equation with 3D energy balance equations for both the acoustic and the optical phonons. This device simulator predicts temperature variations and other physical and electrical parameters across the device for different bias and boundary conditions. The simulation results show insignificant current degradation for nanowire self-heating because of pronounced velocity overshoot effect. In addition, this work explores the role of various placement of the source and drain contacts on the magnitude of self-heating effect in nanowire transistors. This work also investigates the simultaneous influence of self-heating and random charge effects on the magnitude of the ON current for both positively and negatively charged single charges. This research suggests that the self-heating effects affect the ON-current in two ways: (1) by lowering the barrier at the source end of the channel, thus allowing more carriers to go through, and (2) via the screening effect of the Coulomb potential. To examine the effect of temperature dependent thermal conductivity of thin silicon films in nanowire transistors, Selberherr's thermal conductivity model is used in the device simulator. The simulations results show larger current degradation because of self-heating due to decreased thermal conductivity . Crystallographic direction dependent thermal conductivity is also included in the device simulations. Larger degradation is observed in the current along the [100] direction when compared to the [110] direction which is in agreement with the values for the thermal conductivity tensor provided by Zlatan Aksamija.
ContributorsHossain, Arif (Author) / Vasileska, Dragica (Thesis advisor) / Ahmed, Shaikh (Committee member) / Bakkaloglu, Bertan (Committee member) / Goodnick, Stephen (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Radiation-induced gain degradation in bipolar devices is considered to be the primary threat to linear bipolar circuits operating in the space environment. The damage is primarily caused by charged particles trapped in the Earth's magnetosphere, the solar wind, and cosmic rays. This constant radiation exposure leads to early end-of-life expectancies

Radiation-induced gain degradation in bipolar devices is considered to be the primary threat to linear bipolar circuits operating in the space environment. The damage is primarily caused by charged particles trapped in the Earth's magnetosphere, the solar wind, and cosmic rays. This constant radiation exposure leads to early end-of-life expectancies for many electronic parts. Exposure to ionizing radiation increases the density of oxide and interfacial defects in bipolar oxides leading to an increase in base current in bipolar junction transistors. Radiation-induced excess base current is the primary cause of current gain degradation. Analysis of base current response can enable the measurement of defects generated by radiation exposure. In addition to radiation, the space environment is also characterized by extreme temperature fluctuations. Temperature, like radiation, also has a very strong impact on base current. Thus, a technique for separating the effects of radiation from thermal effects is necessary in order to accurately measure radiation-induced damage in space. This thesis focuses on the extraction of radiation damage in lateral PNP bipolar junction transistors and the space environment. It also describes the measurement techniques used and provides a quantitative analysis methodology for separating radiation and thermal effects on the bipolar base current.
ContributorsCampola, Michael J (Author) / Barnaby, Hugh J (Thesis advisor) / Holbert, Keith E. (Committee member) / Vasileska, Dragica (Committee member) / Arizona State University (Publisher)
Created2011
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Description

Reducing the amount of error and introduced data variability increases the accuracy of Western blot results. In this study, different methods of normalization for loading differences and data alignment were explored with respect to their impact on Western blot results. GAPDH was compared to the LI-COR Revert total protein stain

Reducing the amount of error and introduced data variability increases the accuracy of Western blot results. In this study, different methods of normalization for loading differences and data alignment were explored with respect to their impact on Western blot results. GAPDH was compared to the LI-COR Revert total protein stain as a loading control. The impact of normalizing data to a control condition, which is commonly done to align Western blot data distributed over several immunoblots, was also investigated. Specifically, this study addressed whether normalization to a small subset of distinct controls on each immunoblot increases pooled data variability compared to a larger set of controls. Protein expression data for NOX-2 and SOD-2 from a study investigating the protective role of the bradykinin type 1 receptor in angiotensin-II induced left ventricle remodeling were used to address these questions but are also discussed in the context of the original study. The comparison of GAPDH and Revert total protein stain as a loading control was done by assessing their correlation and comparing how they affected protein expression results. Additionally, the impact of treatment on GAPDH was investigated. To assess how normalization to different combinations of controls influences data variability, protein data were normalized to the average of 5 controls, the average of 2 controls, or an average vehicle and the results by treatment were compared. The results of this study demonstrated that GAPDH expression is not affected by angiotensin-II or bradykinin type 1 receptor antagonist R-954 and is a less sensitive loading control compared to Revert total protein stain. Normalization to the average of 5 controls tended to reduce pooled data variability compared to 2 controls. Lastly, the results of this study provided preliminary evidence that R-954 does not alter the expression of NOX-2 or SOD-2 to an expression profile that would be expected to explain the protection it confers against Ang-II induced left ventricle remodeling.

ContributorsSiegel, Matthew Marat (Author) / Jeremy, Mills (Thesis director) / Sweazea, Karen (Committee member) / Hale, Taben (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

This thesis identifies and explains two main problems students face during their internships. The first problem relates to feeling bored at internships due to the simplicity of projects or lack of work. From the interviews conducted, several strategies to avoid this boredom were created, including having employers design education plans

This thesis identifies and explains two main problems students face during their internships. The first problem relates to feeling bored at internships due to the simplicity of projects or lack of work. From the interviews conducted, several strategies to avoid this boredom were created, including having employers design education plans for interns to further their knowledge in programs such as excel during their downtime. The second problem with internships discovered focuses on the gap between what is taught in schools versus what is expected of interns in practice. This thesis identifies several opportunities for improvement in education and strategies on how to handle feeling overwhelmed on intern projects due to lack of knowledge.

ContributorsKomarnyckyj, Katya (Author) / Byrne, Jared (Thesis director) / Crawford, Cassidy (Committee member) / School of Molecular Sciences (Contributor) / Department of Finance (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

This thesis proposes hardware and software security enhancements to the robotic explorer of a capstone team, in collaboration with the NASA Psyche Mission Student Collaborations program. The NASA Psyche Mission, launching in 2022 and reaching the metallic asteroid of the same name in 2026, will explore from orbit what is

This thesis proposes hardware and software security enhancements to the robotic explorer of a capstone team, in collaboration with the NASA Psyche Mission Student Collaborations program. The NASA Psyche Mission, launching in 2022 and reaching the metallic asteroid of the same name in 2026, will explore from orbit what is hypothesized to be remnant core material of an early planet, potentially providing key insights to planet formation. Following this initial mission, it is possible there would be scientists and engineers interested in proposing a mission to land an explorer on the surface of Psyche to further document various properties of the asteroid. As a proposal for a second mission, an interdisciplinary engineering and science capstone team at Arizona State University designed and constructed a robotic explorer for the hypothesized surfaces of Psyche, capable of semi-autonomously navigating simulated surfaces to collect scientific data from onboard sensors. A critical component of this explorer is the command and data handling subsystem, and as such, the security of this system, though outside the scope of the capstone project, remains a crucial consideration. This thesis proposes the pairing of Trusted Platform Module (TPM) technology for increased hardware security and the implementation of SELinux (Security Enhanced Linux) for increased software security for Earth-based testing as well as space-ready missions.

ContributorsAnderson, Kelly Joanne (Author) / Bowman, Catherine (Thesis director) / Kozicki, Michael (Committee member) / Electrical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Over 40% of adults in the United States are considered obese. Obesity is known to cause abnormal metabolic effects and lead to other negative health consequences. Interestingly, differences in metabolism and contractile performance between obese and healthy weight individuals are associated with differences in skeletal muscle fiber type composition between

Over 40% of adults in the United States are considered obese. Obesity is known to cause abnormal metabolic effects and lead to other negative health consequences. Interestingly, differences in metabolism and contractile performance between obese and healthy weight individuals are associated with differences in skeletal muscle fiber type composition between these groups. Each fiber type is characterized by unique metabolic and contractile properties, which are largely determined by the myosin heavy chain isoform (MHC) or isoform combination that the fiber expresses. In previous studies, SDS-PAGE single fiber analysis has been utilized as a method to determine MHC isoform distribution and single fiber type distribution in skeletal muscle. Herein, a methodological approach to analyze MHC isoform and fiber type distribution in skeletal muscle was fine-tuned for use in human and rodent studies. In the future, this revised methodology will be implemented to evaluate the effects of obesity and exercise on the phenotypic fiber type composition of skeletal muscle.

ContributorsOhr, Jalonna Rose (Author) / Katsanos, Christos (Thesis director) / Tucker, Derek (Committee member) / Serrano, Nathan (Committee member) / School of Life Sciences (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Waste pickers are the victims of harsh economic and social factors that have hurt many<br/>developing countries and billions of people around the world. Due to the rise of industrialization<br/>since the 19th century, waste and disposable resources have been discarded around the world to<br/>provide more resources, products, and services to wealthy

Waste pickers are the victims of harsh economic and social factors that have hurt many<br/>developing countries and billions of people around the world. Due to the rise of industrialization<br/>since the 19th century, waste and disposable resources have been discarded around the world to<br/>provide more resources, products, and services to wealthy countries. This has put developing<br/>countries in a precarious position where people have had very few economic opportunities<br/>besides taking on the role of waste pickers, who not only face physical health consequences due<br/>to the work they do but also face exclusion from society due to the negative views of waste<br/>pickers. Many people view waste pickers as scavengers and people who survive off of doing<br/>dirty work, which creates tensions between waste pickers and others in society. This even leads<br/>to many countries outlawing waste picking and has led to the brutal treatment of waste pickers<br/>throughout the world and has even led to thousands of waste pickers being killed by anti-waste<br/>picker groups and law enforcement organizations in many countries.<br/>Waste pickers are often at the bottom of supply chains as they take resources that have<br/>been used and discarded, and provide them to recyclers, waste management organizations, and<br/>others who are able to turn these resources into usable materials again. Waste pickers do not have<br/>many opportunities to rise above the situation they are in as waste picking has become the only<br/>option for many people who need to provide for themselves and their families. They are not<br/>compensated very well for the work they do, which also contributes to the situation where waste<br/>pickers are forced into a position of severe health risks, backlash from society and governments,<br/>not being able to seek better opportunities due to a lack of earning potential, and not being<br/>connected with end-users. Now is the time to create new business models that solve these large<br/>problems in our global society and create a sustainable way to ensure that waste pickers are<br/>treated properly around the world.

ContributorsKapps, Jack Michael (Co-author) / Kidd, Isabella (Co-author) / Urbina-Bernal, Alejandro (Co-author) / Bryne, Jared (Thesis director) / Marseille, Alicia (Committee member) / Jordan, Amanda (Committee member) / Department of Management and Entrepreneurship (Contributor) / Department of Marketing (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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From exploring coffee plantations with an old Irishman in the mountains of Colombia to watching the sun set over the Strait of Gibraltar from the terrace of an ancient Moroccan cafe, this thesis sent Charles and Zane on an elaborate cafe-crawl across ten countries, with stops at a few of

From exploring coffee plantations with an old Irishman in the mountains of Colombia to watching the sun set over the Strait of Gibraltar from the terrace of an ancient Moroccan cafe, this thesis sent Charles and Zane on an elaborate cafe-crawl across ten countries, with stops at a few of the world’s most interesting coffee houses. Some of these cafes, such as the world-renowned Caffé Florian (opened in 1720) and Caffé Greco (1760), are built on long-standing traditions. Others are led by innovators championing high-quality boutique shops, challenging mass production chains such as Starbucks and Tim Hortons. These newer cafes fuel a movement classified as the “Third Wave”. With a foundation gained from specialized courses with Patrick O’Malley, North America’s leading voice in coffee, Zane and Charles conducted first-hand research into the unique coffee preferences of multiple cultures, the emergence and impact of the Third Wave in these countries, and what the future may hold for coffee lovers.

ContributorsFerguson, Charles William (Co-author) / Jarecke, Zane (Co-author) / Eaton, John (Thesis director) / Bonfiglio, Thomas (Committee member) / Dean, W.P. Carey School of Business (Contributor, Contributor) / Department of Marketing (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Description

Since 1975, the prevalence of obesity has nearly tripled around the world. In 2016, 39% of adults, or 1.9 billion people, were considered overweight, and 13% of adults, or 650 million people, were considered obese. Furthermore, Cardiovascular disease remains to be the leading cause of death for adults in the

Since 1975, the prevalence of obesity has nearly tripled around the world. In 2016, 39% of adults, or 1.9 billion people, were considered overweight, and 13% of adults, or 650 million people, were considered obese. Furthermore, Cardiovascular disease remains to be the leading cause of death for adults in the United States, with 655,000 people dying from related conditions and consequences each year. Including fiber in one’s dietary regimen has been shown to greatly improve health outcomes in regards to these two areas of health. However, not much literature is available on the effects of corn-based fiber, especially detailing the individual components of the grain itself. The purpose of this preliminary study was to test the differences in influence on both LDL-cholesterol and triglycerides between treatments based on whole-grain corn flour, refined corn flour, and 50% refined corn flour + 50% corn bran derived from whole grain cornmeal (excellent fiber) in healthy overweight (BMI ≥ 25.0 kg/m2) adults (ages 18 - 70) with high LDL cholesterol (LDL ≥ 120mg/dL). 20 participants, ages 18 - 64 (10 males, 10 females) were involved. Data was derived from blood draws taken before and after each of the three treatments as well as before and after each treatment’s wash out periods. A general linear model was used to assess the effect of corn products on circulating concentrations of LDL-cholesterol and triglycerides. From the model, it was found that the whole-grain corn flour and the 50% refined corn flour + 50% corn bran drive from whole grain cornmeal treatments produced a higher, similar benefit in reductions in LDL-cholesterol. However, the whole grain flour, refined flour, and bran-based fiber treatments did not influence the triglyceride levels of the participants throughout this study. Further research is needed to elucidate the effects of these fiber items on cardiometabolic disease markers in the long-term as well as with a larger sample size.

ContributorsLe, Justin (Author) / Whisner, Corrie (Thesis director) / Ortega Santos, Carmen (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Motor learning is the process of improving task execution according to some measure of performance. This can be divided into skill learning, a model-free process, and adaptation, a model-based process. Prior studies have indicated that adaptation results from two complementary learning systems with parallel organization. This report attempted to answer

Motor learning is the process of improving task execution according to some measure of performance. This can be divided into skill learning, a model-free process, and adaptation, a model-based process. Prior studies have indicated that adaptation results from two complementary learning systems with parallel organization. This report attempted to answer the question of whether a similar interaction leads to savings, a model-free process that is described as faster relearning when experiencing something familiar. This was tested in a two-week reaching task conducted on a robotic arm capable of perturbing movements. The task was designed so that the two sessions differed in their history of errors. By measuring the change in the learning rate, the savings was determined at various points. The results showed that the history of errors successfully modulated savings. Thus, this supports the notion that the two complementary systems interact to develop savings. Additionally, this report was part of a larger study that will explore the organizational structure of the complementary systems as well as the neural basis of this motor learning.

ContributorsRuta, Michael (Author) / Santello, Marco (Thesis director) / Blais, Chris (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / School of Molecular Sciences (Contributor) / School of Human Evolution & Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05