Digital Commons Network^™

Integrated Structural Monitoring Of Composite Materials Via Distributed Optical Sensor, Jung-Ting Tsai

Open Access Theses

Measuring the strain history in pre-impregnated thermoset composites during the curing process provides valuable data for manufacturing specification development, quality control, diagnostics of dimensional stability, and validation of cure models. Unlike traditional Fiber-Bragg Grating-based methods, the Distributed Optical Sensors (DOS) provide information along the entire optical fiber distance (optical path length) of the sensor embedded in the laminate for strain measurement. This study’s unique contribution to the field is the coupling of the optical sensor monitoring of composite cure strain with models of the cure kinetics, viscosity, and glass transition temperature of the thermoset matrix. Coupling the strain measurements to …

Landscape Transitions And Socioeconomic Drivers As Predictors Of Fire Frequency, Mariam Gabriela Valladeres Castellanos

Open Access Theses

Fire prediction systems rely on meteorological descriptors and fuel characteristics to determine fire risk at national scales. However, at a regional scale, anthropogenic dynamics play an important role in determining fire ignition, as well as spatial and temporal distributions. Under an increasing fire activity scenario projected for the next century, Mediterranean ecosystems are particularly fragile regions. Fire variability driven by human stressors is the main threat to the native vegetation and human populations in these regions. The inclusion of anthropogenic indicators on fire prediction systems, especially within Mediterranean ecosystems, is key to developing accurate predictions and effective fire management efforts. …

Embedding Sustainability Into The Wine Sector Through The Application Of Life Cycle Management Tools, Andres Eduardo Valero

Open Access Theses

According to the United Nations, by 2050, if we keep the current natural resources usage trend, we will require three planets to support the lifestyle of 9.6 billion people, [1]. Undoubtedly to overcome this challenge is necessary we change not only our consumption pattern but also how the production system works. In one hand a systemic approach is required to reduce natural resources demand and degradation while increasing social welfare along the whole lifecycle of each of our economic activities. On the other hand, the member of the society needs to acknowledge the environmental, social, and economic impact of their …

Waste Materials And Management: Lessons From The Flint Water Crisis In Michigan And Blast Furnace Slag Usage In Indiana, Tianqi Wang

Open Access Theses

Two aspects of solid waste management were investigated for this thesis. The first effort focused on better understanding solid waste management before, during, and after the large-scale 2015 drinking water lead crisis in Flint, Michigan. When large drinking water systems are unable to deliver safe water, the provision of emergency water supplies becomes a necessity. The author investigated waste management challenges associated with the large-scale drinking water disaster. In October 2015, more than 90,000 people were directed not to use their lead contaminated water, but instead use emergency drinking water and in-home filters. Discussions with organizations that responded to the …

Optimal Design And Control Of Residential Air-Conditioning Equipment With Integrated Thermal Storage, Aaron Tam

Open Access Theses

Although thermal energy storage (TES) has been integrated with commercial building cooling systems, it is rarely considered in residential buildings. In recent years, though, variable utility rates have become more available to residential customers to incentivize demand reductions during midday peak hours. TES allows consumers to store cooling during hours with low demand and reduce the peak demand from air conditioning. From an economic perspective, the integration of storage can result in reduction in the installed cost of the primary cooling equipment because of the reduction in the peak cooling requirement. However, this is counteracted by the additional costs associated …

Understanding Undergraduate Chinese International Student Perceptions And Usage Of Facebook, Yushan Wei

Open Access Theses

The study tried to understand undergraduate Chinese international student perceptions and usage of Facebook. Ten undergraduate Chinese international students from a Midwestern university were recruited in this study. Half of them were senior and half of them were freshmen. Semi-structured interviews and survey were used in collecting data. Based on the analysis of data from all data source, several themes emerged and were categorized under purpose, adoption and usage. Moreover, data also provided explanation of the decline of Facebook usage among undergraduate Chinese international students as they stayed in the U.S. Findings of this study included the usability issues of …

Investigating The Effects Of Cobalt And Nickel Mixtures On Tungsten Toxicity In Zebrafish (Danio Rerio), Ola Wasel

Open Access Theses

Tungsten (W) is a refractory metal that is used in a wide range of applications. Initially perceived as immobile in the environment, tungsten replaced lead and uranium in munition and military applications. Recent studies report movement and detection of tungsten in soil and potable water sources increasing the risk of human exposure. In addition, experimental research studies observed adverse health effects associated with exposure to tungsten alloy, raising concerns on tungsten toxicity with questions surrounding the safety of exposure to tungsten alone or in mixtures with other metals. Tungsten is commonly used as an alloy with nickel (Ni) and cobalt …

The Impacts And Distribution Of State Incentives On Farm To School Programs: A Probability Model, Jonathan Zerrell Weir

Open Access Theses

Despite the passage of the Healthy Hunger-Free Kids Act in 2010, Farm to School participation rates remains low or unequally distributed in states across the US. This study takes on the task of identifying strong state-sponsored programs that incentivize participation rates across various demographics. Using a series of logits (N=9,004), the study analyzes Farm to School policy effects on program participation across key demographic variables, such as the percent of students who receive free or reduced lunch, locale, and racial demographics. In the model, higher income and more urban school districts likelihood of participating in Farm to School drastically improve, …

Automated Hardwood Lumber Grading, Logan Wells

Open Access Theses

Grading lumber is a process of assigning a quality measurement and thus dollar value to individual boards. Throughout the entire hardwood manufacturing process and individual board can be graded multiple times from when the board is first sawn from the log, before and after drying and when it reaches the end manufacturer. For hardwood lumber both appearance and structural soundness factor into the grade of a board. The National Hardwood Lumber Association (NHLA) was created to establish a uniform standard for grading hardwood lumber. Many companies still have proprietary grades specific to their business, but the vast majority of hardwood …

Flexible Automation For Meso And Micro-Scale Manipulation And Assembly, Vinoth Venkatesan

Open Access Theses

A complete micro-manipulation and assembly system is proposed in this work, capable of manipulation of parts at the micro/meso scale, path-planning, assembly sequencing planning and flexible soldering to attach these parts in the final assembly. The work presented here addresses the issues associated with interacting with objects at such a small scale and their interactions with the environment by looking at various manipulation and assembly tasks, providing solutions to these problems, and analyzing the results. First, the problem of assembling is resolved using a Sub-Assembly based Sequence Planning algorithm which was implemented in this system and the results are demonstrated …

An Eye-Tracking Study Of User Behavior On Reading Scrolling Text, Wenjie Wu

Open Access Theses

This study investigated the effect of parallax scrolling on users’ reading and scrolling behavior in text-heavy websites. We designed several text-heavy webpages and applied parallax scrolling effect. Twenty-five students participated in this study and were assigned to two groups to read websites with or without parallax scrolling effect in different sequences. We used eye-tracking, retrospective think aloud, and interview to collect data.

Results showed that people have distinctly different scrolling habits and reading habits which have a huge influence on how they perceive parallax effect. People who prefer to scroll down a little and read a few lines of text …

Optimized Angles Of The Swing Hyperspectral Imaging Tower For Single Corn Plant, Libo Zhang

Open Access Theses

During recent years, hyperspectral imaging systems have been widely applied in the greenhouses for plant phenotyping purposes. Current imaging systems are mostly designed as either top view or side view imaging mode. Top-view is an ideal imaging angle for top leaves which are often more flat with more uniform reflectance. However, most bottom leaves are either blocked or shaded from top view. From side view, most leaves are viewable, and the entire structure can be imaged. However, at this angle most of the leaves are not facing the camera, which will impact the measurement quality. At the same time, there …

Can U.S. Agriculture Provide Agro-Pharms For Malaria Treatment?, Chong Zhao

Open Access Theses

For policy analysis, interest is in investigating the effect of a subsidy policy-switching regime on agro-pharms investment through the theory of investment under uncertainty. It considers the probability of a policy implemented when it is not in effect and the probability of removal when it is in effect. Poisson type policy jumps models a discrete subsidy policy, which provides pharmaceutical plants financial assistance to manufacture Artemisinin-based therapies. A case study analysis determines if Artemisinin efficiency improvements can result in the development of a commercially viable U.S. agribusiness investment opportunity. Accounting for uncertainty, irreversibility, and adoption timing in establishing an Artemisinin …

Development Of A Single-Ended Laser-Absorption Spectroscopy Sensor For High-Temperature Gases, Yuzhe Zhou

Open Access Theses

Tunable diode-laser-absorption spectroscopy (TDLAS) sensors have been one widely-used laser-diagnostic technique that offers great potential for non-intrusive, time-resolved and multi-parameter sensing in combustion systems. These sensors have been used for performance testing, model validation and feedback control of combustors [1–9]. During operation, monochromatic laser light with a specific wavelength is transmitted through the test gas and collected on a photodetector. Gas conditions such as temperature and composition are then inferred by comparing the measured amount of light that is absorbed with that predicted by spectroscopic models.

In this thesis, the design and demonstration of a compact single-ended laser-absorption spectroscopy (SE-LAS) …

Mixed Material Fabrication For Rapid Prototyping, Sundararajan Venkatraghavan

Open Access Theses

Current Rapid prototyping tools although reduce development time, they still have several restrictions such as print volume and print times. Through this thesis, two prototyping kits are proposed, a rod connector based, user controlled computational support system that re-purposes surface models and transforms them into structurally scaffolded constructs with movable joints; and a planar connector based system that implements movable joints to create functional prototypes. The rod based system enables users to interactively personalize scaffolded structures by re-purposing existing surface mesh models; analyze scaffolded constructs in-situ for better structurality, add movable joints to increase functionality, and attach personalized appearances to …

Pre-Service Teachers' Understanding Of Geometric Reflections In Terms Of Motion And Mapping View, Murat Akarsu

Open Access Dissertations

In this manuscript, I describe a study of pre-service secondary mathematics teachers’ (PTs) understanding of geometric reflection in terms of a motion and a mapping views. PTs often have a motion view of geometric reflection based on their understanding of reflection line, domain, and plane. A motion view is a preliminary perspective developed prior to the construction of a mapping view. PTs need a mapping view of geometric reflection, and to be conscious of sub-concepts of a mapping view involved reflection line, domain, and plane. However, there is no clear evidence documenting how a learner’s motion view evolves to produce …

She Is A Computer Scientist: A Quantitative Comparison Between The Effectiveness Of Game Design Studios And Robotics At Enhancing Women's Learning Of, Self-Efficacy In, Attitudes Toward, And Domain Identification With Computer Science, Ali Nazil Alshammari

Open Access Dissertations

The underrepresentation of women in computer science is a serious issue with ramifications that affect not only women working in the field, but also the field at large and the national economy. While the problem is attributed to several interconnected causes, such as computer knowledge, experience, and familiarity; they do not tell the entire story, nor do they point to a global trend. Studies indicate that these factors did not stop the computer science field from achieving a balanced male-female ratio in non-western countries. Since no single factor can be attributed as the primary cause of this complicated problem, and …

Translocation Of Neonicotinoid In Maize And Nontarget Impacts To Water And Soil, Adam Alford

Open Access Dissertations

The neonicotinoids are a relatively new group of insecticides, first commercially available in the early 1990s, and have become the most widely used insecticide class in the world. Neonicotinoids can be utilized in a variety of ways however the vast majority are applied as a seed coating prior to planting. These neonicotinoid seed treatments (NST) are primarily used within field crops, where their main use is as a prophylactic, insurance based approach to pest management. By 2011 US adoption rates exceeded >80% in maize and 34-44% in soy. This widespread and rapid use has not been justified with a corresponding …

Comparison Of Brachypodium And Wheat Response To Hessian Fly, Abdelrahman Ahmed Abdelhady Mohamed Awad

Open Access Dissertations

Wheat (Triticum aestivum) yield is limited by biotic stresses such as Hessian fly [Mayetiola destructor (Say)] attack which causes a significant annual loss. Previous studies have shown that Brachypodium distachyon is resistant to Hessian fly infestation. Since B. distachyon has advantages over wheat to be used as a model plant in genetic and genomics, we compared the response of 5 wheat lines (4 resistant lines, harboring different Hessian fly-resistance H genes, and 1 susceptible line to Hessian fly infestation) to B. distachyon at early stages [12 hours, 1 day, 3 days and 5 Days After Hessian fly egg-Hatch (DAH)] of …

Interparental Conflict As A Context For Early Child-Parent Attachment Relationships, Laura Yanett Anaya

Open Access Dissertations

The present study explored the concurrent relations between interparental conflict strategies and early child-parent attachment relationships, while considering potential mediating (i.e., parental sensitivity) and moderating (i.e., involvement of child in conflict) variables in the relations. A nonclinical sample of mostly non-Hispanic Caucasian triads (i.e., mother, father, child) were recruited. Parental sensitivity and children's attachment security were observed across four visits: one visit was in the home with mother, one visit was in the home with father, one visit was in the park with mother, and one visit was in the park with father. In a fifth visit, in the research …

East Asian International Students' Interdependent Happiness: The Role Of Acculturative Stress, Dialectical Thinking, And Collectivistic Coping, Yaping Huang Anderson

Open Access Dissertations

The purpose of this study was to understand the relationships among East Asian international students cultural construals of stress (i.e., acculturative stress), psychological wellbeing (i.e., interdependence happiness), cognitive appraisal (i.e., dialectical thinking), and coping skills (i.e., collectivistic coping: seeking social support and forbearance) using Chun, Moos, and Cronkite’s (2006) stress and coping model as the theoretical framework. This study was the first attempt to propose a theoretical framework elucidating the possible relationships among these variables through a cultural lens. A total of 313 self-identified East Asian international students participated in the online-based survey. Using a hierarchical regression, the results revealed …

Avian Immunogenetics And Evolution Of A Passerine Bird In The Face Of Malarial Parasites, Jennifer D. Antonides

Open Access Dissertations

A key goal of evolutionary biology is understanding the complex mechanisms underlying adaptive evolution, and the study of the co-evolution of hosts and parasites is a primary tool. The work in this dissertation involves exploring the evolution of avian immune genes in the context of phylogeny and malarial parasitic infection using next generation sequencing approaches. The bananaquit (Coereba flaveola) is a Caribbean passerine bird and a common host of haemosporidian parasites which cause avian malaria (Plasmodium spp. and Haemoproteus spp.). The genes of a host’s immune system, including those of the Major Histocompatability Complex (MHC) of the adaptive immune system …

An Overall Policy Decision-Support System For Educational Facilities Management: An Agent-Based Approach, Haya Bader Albader

Open Access Dissertations

Although K-12 public school facilities infrastructure investments are second only to highways, schools continue to suffer from an approximately $38 billion annual funding gap. Massive reductions in funding are forcing school districts to make tough decisions to optimize maintenance expenditures. Over the last three decades, a huge body of research has determined that the condition of school facilities do affect student health and performance, and some have further demonstrated that schools are overwhelmed by deteriorating facilities that threaten the health, safety, and learning opportunities of students. The currently available educational facility management approaches oversee the influence of the complex and …

Data-Driven Resource Allocation In Virtualized Environments, Lianjie Cao

Open Access Dissertations

Modern advances in virtualization technologies have revolutionized the way we build and manage computer systems. Virtualization technologies, however, adversely impact the predictability of system performance. This introduces several challenges in balancing performance and resource utilization.

In this dissertation, we explore and address performance challenges introduced by virtualization in two application scenarios: network functions virtualization and distributed network emulation.

First, we investigate the performance of virtualized network functions (VNFs) and propose a framework, NFV-VITAL, that characterizes performance impacts of hardware and software options and determines the optimal configuration for initial deployment of a VNF. Then we propose a system, Elastic resource …

A Framework For Comparative Life-Cycle Evaluation Of Alternative Pavement Types, Saeed Alqadhi

Open Access Dissertations

Researchers and practitioners agree that the selection of an appropriate pavement surface material type should be made based on a comprehensive evaluation that incorporates the costs and benefits associated with each alternative for the stakeholder. The most appropriate material type generally is the most cost-effective alternative over the pavement life cycle. Hypothetically, the most appropriate material type will vary across the various geographical regions of the U.S. because material costs and performance are influenced by the deterioration agents at play and the construction costs in a region. To address this issue, this dissertation proposes a comprehensive methodology to identify the …

Modeling Of Bearing Dynamics Using Combined Efem-Dem Method, Lijun Cao

Open Access Dissertations

The objective of this investigation was to develop a 3D dynamic model to study the rotorbearing- housing system. To achieve the objective, an existing dynamic bearing model (DBM) was combined with a flexible bearing housing model and a flexible rotor model. The DBM is based on the discrete element method (DEM), in which all bearing components are assumed to be rigid and have six degrees of freedom. The 3D explicit finite element method (EFEM) was used to develop the flexible housing and rotor models. To couple the bearing outer race (OR) with housing, a novel algorithm was developed to detect …

‘Makingthings Happen’ In Cross-Sector Partnerships: A Multiple Case Study, Priyanka Shah Brunese

Open Access Dissertations

Cross-sector collaborative partnerships aim to bring resources and knowledge from their particular sectors to provide innovative solutions in response to current social, economic and environmental problems, and for developing policies and processes for emergent issues. However, cross-sector partnerships involving public (i.e., institutions of higher education), private, and nonprofit organizations are complex and dynamic systems that are extremely difficult to manage once they have been established. Organizations spanning different sectors not only have dissimilar operating models, working cultures, values, and leadership styles, but are driven by different motives in joining the partnership thereby making the act of collaborating very challenging. When …

Assessment Of Urbanization Impacts On Surface Runoff And Effects Of Green Infrastructure On Hydrology And Water Quality, Jingqiu Chen

Open Access Dissertations

Urbanization is one of the most important anthropogenic modifications of the global environment. It has significant impacts on hydrologic processes and water quantity and quality. Research related to urbanization impacts on surface runoff has focused on changes up to the watershed scale. However, quantitative assessment at a national scale is scarce. Parallel to urbanization impacts, climate is also one of the greatest challenges facing humanity today and its effects are already being felt from strengthened storms and rising sea levels to changing temperature and weather patterns. The adverse impacts of urbanization and climate can converge in synergistic ways, which may …

A Solidarity Economy On The Border: Examining Historical And Contemporary Case Studies In El Paso, Texas As De Facto Contributors To A U.S.-Based Movement, Michelle E. Carreon

Open Access Dissertations

This dissertation examines a contemporary U.S.-based solidarity economy movement, which emphasizes economic practice and ideology that prioritize people and planet over profit. In a neoliberal era that is characterized by economic injustice and continued cutting of social services and programming, a solidarity economy framework offers an alternative. Situated within a growing scholarship, this study examines historical and contemporary examples of solidarity economy-related efforts and praxis in the border city of El Paso, Texas.

The historical case of the Houchen settlement house and the contemporary case of the women-led grassroots community organization, La Mujer Obrera (LMO), illustrate significant ways in which …

The Human Dimensions Of Invasive Plant Management On Family Forestlands: A Case Study In Indiana, Mysha K. Clarke

Open Access Dissertations

Invasive plant management is an increasing concern in socio-ecological systems. Ecologically, invasive plants can displace native species, reduce forest health and productivity, and degrade recreational areas. From a socio-economic perspective, the United States spend approximately USD 137 annually in damage and control costs from invasive plants and animals. Despite these impacts, invasive plants continue to spread in forest ecosystems because of various anthropogenic factors like trade, transportation, climate change, and limited regulation in many states. It is pivotal to consider the role of family forest owners (FFOs) in invasive plant management in forest ecosystems because collectively they own 36% of …