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The Aging And Impacts Of Atmospheric Soot: Closing The Gap Between Experiments And Models, Ogochukwu Yvonne Enekwizu

Dissertations

The main goal of this dissertation is to generate data and parameterizations to accurately represent soot aerosols in atmospheric models. Soot from incomplete combustion of fossil fuels and biomass burning is a major air pollutant and a significant contributor to climate warming. The environmental impacts of soot are strongly dependent on the particle morphology and mixing state, which evolve continuously during atmospheric transport via a process known as aging. To make predictions of soot impacts on the environment, most atmospheric models adopt simplifications of particle structure and mixing state, which lead to substantial uncertainties. Using an experimentally constrained modeling approach, …

Performance Optimization Of Big Data Computing Workflows For Batch And Stream Data Processing In Multi-Clouds, Huiyan Cao

Dissertations

Workflow techniques have been widely used as a major computing solution in many science domains. With the rapid deployment of cloud infrastructures around the globe and the economic benefits of cloud-based computing and storage services, an increasing number of scientific workflows have migrated or are in active transition to clouds. As the scale of scientific applications continues to grow, it is now common to deploy various data- and network-intensive computing workflows such as serial computing workflows, MapReduce/Spark-based workflows, and Storm-based stream data processing workflows in multi-cloud environments, where inter-cloud data transfer oftentimes plays a significant role in both workflow performance …

The Stability Of Nanobubbles And Its Application In Contaminated Sediment Treatment, Shaini Dilsha Aluthgun Hewage

Dissertations

This dissertation consists of two sections. First, nanobubbles' stability and behavior are studied using experimental and theoretical approaches. Second, nanobubbles application combined with ultrasound to remediate contaminated sediments is discussed.

The stability study consists of four sections. (i). Laboratory investigation to determine bubble size distributions and zeta potentials for different gases, pH levels, temperatures, and salt conditions. (ii). A theoretical study based on the diffused double layer theory to explain nanobubbles' behavior in different NaCl concentrations. (iii). Nanobubbles' stability in electrolyte solutions under different ion valencies using deionized water, NaCl, Na₂SO₄, Na₃PO₄, …

Modeling Mass Transfer And Chemical Reaction In Industrial Nitrocellulose Manufacturing Processes, Francis Patrick Sullivan

Dissertations

A series of models are proposed to describe the production of military grade nitrocellulose from dense cellulose materials in mixtures of nitric acid, sulfuric acid, and water. This effort is conducted to provide a predictive capability for analyzing the rate and extent of reaction achieved under a range of reaction conditions used in the industrial nitrocellulose manufacturing process for sheeted cellulose materials. Because this capability does not presently exist, nitrocellulose producers have historically relied on a very narrow range of cellulose raw materials and resorted to trial and error methods to develop processing conditions for new materials. This tool enables …

Small-Scale Dynamics Of Photospheric Magnetic Activities And Their Chromospheric Responses, Jiasheng Wang

Dissertations

The evolution of photospheric magnetic fields is considered as the fundamental source of forming atmospheric structures and triggering most solar activities, including flares and mass ejections on various scales (CMEs, jets, etc.). With the implementation of high-resolution observational instruments, small-scale details of magnetic features are recognized that can provide important information regarding the evolution in active regions and the connection between photospheric magnetic reconnection and jet-like ejections in the quiet Sun. This research takes advantage of the exceptionally high-resolution measurements of vector magnetic field and imaging observations by the Goode Solar Telescope, and UV/EUV imaging observations from space-based instruments. The …

Blast Shock-Wave Characterization In Experimental Shock Tubes, Sudeepto Kahali

Dissertations

Blast-induced traumatic brain injuries have affected U.S. soldiers deployed for extended periods in the gulf and Afghanistan wars. To identify the biomechanical and biochemical mechanisms of injury, critical in the identification of diagnostic and therapeutic tools, compressed gas-driven shock tubes are used by investigators to study shockwave-animal specimen interactions and its biological consequences. However, shock tubes are designed and operated in a variety of geometry with a range of process parameters, and the quality of shock wave characteristics relevant to field conditions and therefore the study of blast-induced traumatic brain injuries suffered by soldiers is affected by those conditions. Lab-to-lab …

Semantic, Integrated Keyword Search Over Structured And Loosely Structured Databases, Xinge Lu

Dissertations

Keyword search has been seen in recent years as an attractive way for querying data with some form of structure. Indeed, it allows simple users to extract information from databases without mastering a complex structured query language and without having knowledge of the schema of the data. It also allows for integrated search of heterogeneous data sources. However, as keyword queries are ambiguous and not expressive enough, keyword search cannot scale satisfactorily on big datasets and the answers are, in general, of low accuracy. Therefore, flat keyword search alone cannot efficiently return high quality results on large data with structure. …

Countering Internet Packet Classifiers To Improve User Online Privacy, Sina Fathi-Kazerooni

Dissertations

Internet traffic classification or packet classification is the act of classifying packets using the extracted statistical data from the transmitted packets on a computer network. Internet traffic classification is an essential tool for Internet service providers to manage network traffic, provide users with the intended quality of service (QoS), and perform surveillance. QoS measures prioritize a network's traffic type over other traffic based on preset criteria; for instance, it gives higher priority or bandwidth to video traffic over website browsing traffic. Internet packet classification methods are also used for automated intrusion detection. They analyze incoming traffic patterns and identify malicious …

Novel Applications Of Mass Spectrometry For Quantitation And Reaction Mechanism Elucidation, Pengyi Zhao

Dissertations

Mass spectrometry (MS) has been growing as one of the most widely used tools in the field of analytical chemistry. Various applications have been developed to harness the high sensitivity and specificity of mass spectrometric analysis. In this dissertation, two major challenges are addressed. By developing mass spectrometric-based methods, absolute quantitation of proteins/peptides have been achieved. Elucidation of various reaction mechanisms are also enabled. These are the focuses of this dissertation.

In Chapters 2 to 4, a novel quantitation method is developed, titled as coulometric mass spectrometry (CMS). The strength of this method is that no reference standard or isotope-labeled …

Convergence Of The Boundary Integral Method For Interfacial Stokes Flow, Keyang Zhang

Dissertations

Boundary integral numerical methods are among the most accurate methods for interfacial Stokes flow, and are widely applied. They have the advantage that only the boundary of the domain must be discretized, which reduces the number of discretization points and allows the treatment of complicated interfaces. Despite their popularity, there is no analysis of the convergence of these methods for interfacial Stokes flow. In practice, the stability of discretizations of the boundary integral formulation can depend sensitively on details of the discretization and on the application of numerical filters. A convergence analysis of the boundary integral method for Stokes flow …

Development Of Novel Membranes For Nanocarbon Enhanced Separation With Application In Biofuels And Solvent Recover, Oindrila Gupta

Dissertations

Pharmaceutical industries historically have had one of the highest amounts of solvent waste generated per unit of drug manufactured. Energy requirements and carbon footprint of current solvent recycling processes tend to be quite high, and the incineration of the solvents for waste disposal produces toxic air emissions. Also, rapidly increasing demand for energy and strict regulation on engine pollutant emissions have necessitated the use of alcohol as carbon-neutral fuels. Thermal distillation is one of the most common methods for the separation of alcohol-water mixtures. However, its application is limited due to energy requirements and high operating costs, and heating to …

Predicting Bulk-Scale Properties Of Pharmaceutical Powders From Their Particle-Scale Dimensionless Measures, Kuriakose T. Kunnath

Dissertations

Loose powder packing and flowability are both important bulk properties to consider in relation to pharmaceutical tablet and capsule manufacturing. These properties as well as cohesive powder agglomeration tendency impact the efficiency of various processes such as feeding, blending, conveying, and compaction, and could have an adverse effect on final drug product. Pharmaceutical powders are often milled to fine sizes (<100 gm) for dissolution improvements via increased available surface area. However, such particle size reductions lead to inadequate bulk powder properties due to high cohesion among the individual particles. Recent work has demonstrated the ability of nano-silica dry coating techniques to significantly decrease interparticle forces without changes in particle size. In this work, the ability to predict properties such as powder bed porosity, flowability, and particle agglomeration both before and after nano-silica dry coating is examined, along with assessment of the extent of property enhancements after dry coating. Previous studies have utilized empirical approaches to build property prediction models. However, such approaches lack physical fundamentals which dictate bulk powder behavior and would be unable to account for the effects of dry powder coating. Incorporation of physics can be done via computation of the granular Bond number, as is done in this study for a large dataset of commonly used pharmaceutical powders, with wide variations in particle size, shape, density, and surface roughness. Predictive capability of current Bond number models is investigated, reasons for outliers are elucidated, and amendments to improve prediction is attempted. Overall, the aim of this work is to expand generalizability of Bond number models to a wider variety of particles, and extend its use from single powders to multi-component mixtures. The major outcome of this work is the development of a predictive framework that is expected to simplify pharmaceutical dry powder formulation development, reduce required experimental testing, and provide quantifiable estimates to aid processing route decision making.

A Longitudinal Investigation Of Functional Activity Changes From Vision Therapy: A Study Of Binocularly Normal Controls And Patients With Convergence Insufficiency, Cristian Morales Carrasco

Dissertations

Convergence insufficiency (CI) is a binocular vision dysfunction in which the person has difficulty maintaining a sustained fixation on an object in the near field of view. This condition is present in about 5% of the general population and with a greater prevalence in patients with traumatic brain injury or attentional deficit hyperactivity disorder. One therapeutic intervention for CI is Office-Based Vergence and Accommodative therapy (OBVAT) which is successful in about 75% of the pediatric and young adult population. The neural mechanism by which OBVAT leads to a sustained reduction in visual symptoms is not fully understood. Vergence eye movements …

Addressing Ad-Blocking Challenges In Online Publishing: A Data Science Approach, Shuai Zhao

Dissertations

The revenue of online display advertising is expected to reach 389 billion U.S. dollars globally in 2021. However, the fast increase in ad-blocker usage impacts publishers' ad revenue and the ad-supported free web. Faced with this problem, many online publishers choose either to cooperate with ad-blocker software companies to show acceptable ads or to build a wall that requires users to whitelist (i.e., turn off ad-blockers) for content access. This dissertation aims to deepen the understanding of existing counter-ad-blocking strategies and further explore how to address ad-blocking challenges through a data science approach.

The dissertation starts with investigating and identifying …

Identifying Successful Strategies Within An Extrinsic Reward System To Improve Behavior In The Alternative School Setting, Christian Burner

Dissertations

Purpose: The purpose of this Delphi study was to identify strategies that are successful within a school-wide extrinsic rewards system to improve alternative school student behavior in the alternative school setting. A second purpose was to rate the effectiveness of the identified strategies for improving alternative school student behavior in the alternative school setting.

Methodology: This study used a Delphi method, consisting of 3 rounds, to collect data from alternative schoolteachers who are experts in implementing strategies within a school-wide extrinsic rewards system. In Round 1, participants were asked to identify strategies to improve student behavior in the alternative school …

Mental Health And The High-Performing Student: A Study Of Stressors And Effective Supports For High-Achieving High School Students, Jodi Boyle

Dissertations

Purpose: The purpose of this qualitative phenomenological study was to explore the lived experiences of high-achieving 11th- and 12th-grade high school students participating in International Baccalaureate (IB), Advanced Placement (AP), or Honors courses. An additional purpose of this study was to identify the academic and social stressors experienced by students and the coping strategies used to overcome them.

Methodology: This study used a phenomenological research design to describe the lived experiences, academic and social stressors, and coping strategies of high-achieving students. For this study, in-depth interviews were conducted to understand the academic and social experiences of students participating in …

A Grounded Theory Of Directors' Of Nursing Perceptions On Caring: Post-Francis Paradoxes, Maggie Ann Davies

Dissertations

This study explores the perceptions of Directors of Nursing from NHS acute Trusts in England, on caring practices. The aspiration of the NHS is to deliver good care to patients and their families. The NHS constitution states that the 'NHS is there to improve health and wellbeing, and it touches our lives at times of basic human need, when care and compassion are what matter most' (DH 2013:2). However, recent inquiries into poor care have created a searching debate regarding standards of nursing care, leadership, culture and practice. Directors of Nursing play a significant role in influencing care, as they …

A Phenomenological Study On The Impact Of Servant Leadership For Establishing A Culture Of High Performance As Perceived By High School Principals, Darrick Rice

Dissertations

Purpose: The purpose of this phenomenological study was to explore and describe the perceived impact of Patterson’s (2003) 7 servant leadership constructs on high school principals in establishing a culture of high performance.

Methodology: The qualitative phenomenological study described the lived experiences of high school principals who lead schools that have implemented Patterson's (2003) 7 servant leadership constructs for establishing a culture of high performance in Los Angeles County, California. The researcher was a part of 8 peer researchers and 2 faculty advisors. The data collection included virtual face-to-face semi structured interviews using a protocol developed by the thematic team. …

Determinants Of Financial Success Of Large Law Firms, James Xu

Dissertations

Prior research has established that leadership characteristics, job equity perception, and client satisfaction are all associated with a firm’s financial performance. This study tested hypotheses about these variables based upon Upper Echelons Theory, Adams Equity Theory, and Stakeholder Theory, in the context of 110 large U.S. law firms. The analysis revealed that (1) the racial diversity of the firm’s management committee is positively associated with the firm’s financial performance; (2) the average employee salary has a positive and U-shaped relationship with the firm’s financial performance; (3) the average employee salary has a positive relationship with the firm’s client satisfaction; (4) …

Mental Health And Discipline In California Community Schools, Damien Phillips

Dissertations

Purpose: The purpose of this mixed method study was to determine if there is a difference in achievement, absenteeism, graduation rates and suspension for students enrolled in community schools that do and don’t have access to school-based mental health services. In addition, it was the purpose to identify and describe the practices most effective in improving attendance, reduction of suspension, achievement and graduation as perceived by community school employees.

Methodology: This mixed-method dissertation attempted to determine the difference between California county community schools for expelled students who have had access to school-based mental health and those who do not as …

Saudi Elementary Mathematics Teachers’ Knowledge For Teaching Fractions, Mona Khalifah A Aladil

Dissertations

Recent reform efforts in Saudi Arabia attend to mathematics instruction with a great deal of emphasis to improve Saudi mathematics education. Studies in different countries have confirmed that teachers’ mathematical knowledge for teaching plays an important role in mathematical quality of instruction and students’ achievement (e.g., Ball, 1990; Baumert et al., 2010; Hill, Rowan, & Ball, 2005). Yet few studies about mathematics teachers’ knowledge for teaching have been conducted in the Saudi context. This study investigates Saudi elementary mathematics teachers’ knowledge for teaching in the content strand of rational numbers with an emphasis on fractions, which is an important step …

Response Of Deep Aquifers To Climate Variability, Karem Fathy Abdelgaber Abdelmohsen

Dissertations

Our recent analysis of Temporal Gravity Recovery and Climate Experiment (GRACE) solutions over the largest aquifer system in Africa (the Nubian Sandstone Aquifer System: NSAS) revealed that while the response of deep aquifers to climatic variations remains a relatively slow process that takes thousands to tens of thousands of years, there is a much faster response in aquifers that are characterized by dense networks of faults, fractures and karst as is the case with the NSAS. This rapid groundwater flow, when it occurs, is detected as an increase in GRACE_TWS over areas downgradient and distant (hundreds of km) from …

The Experience Of Living With Hypertension: Lessons From A Cohort Of Older Men, Junjira Seesawang

Dissertations

Poor adherence to treatment and poorly controlled hypertension are common in older men, especially in rural areas. Knowledge about the experience of living with hypertension among older men is important for developing nursing practices to enhance treatment adherence. However, little is known about the personal experiences of older men with hypertension. This dissertation includes three papers that address the following: (1) the experiences of men with hypertension, based on a review of literature, (2) factors influencing the ability to self-manage hypertension among older adults in Asian countries, based on a review of qualitative studies, and (3) grounded theory study exploring …

An Educational Initiative To Prevent Unnecessary Hospitalization For Hospice Patients, Alkeisha H. Mims

Dissertations

Avoidable hospitalizations of hospice patients cost Medicare $3 billion a year. When hospice nurses are able to identify early signs and symptoms of acute illness and provide appropriate interventions to prevent such admissions, 20-60% of the hospitalizations are preventable. The practice problem addressed in this quality improvement doctor of nursing project was the 30% hospital admission rate of hospice patients as evidenced by chart review, admission data, and revocation data. The first purpose of the project was to identify evidence-based nursing care paths in the literature for the top 5 medical diagnoses related to avoidable hospital admissions. The second purpose …

Exploring The Relationships Between And Among Registered Nurses' Spiritual Well-Being, Spiritual Care Perspectives, And Their Provision Of Spiritual Care In Acute Care Settings, Barbara J. Kitchener

Dissertations

Despite acknowledgment that spiritual care is an essential aspect of holistic nursing care, nurses often feel ill-prepared for, uncomfortable with, and uncertain about providing spiritual care. Studies have indicated that nurses who have a strong sense of their own spiritual well-being and/or a positive perspective [attitude, value, belief] about spiritual care are more inclined to provide spiritual care to their patients. However there is a scarcity of such studies among acute care nurses. This descriptive correlational study aimed to explore relationships between and among acute care nurses' spiritual well-being (SWB), spiritual care perspectives (SCP), and their provision of spiritual care …

Contextual Factors Influencing The Acute Care Registered Nurse's Response To Clinical Alarms, Kathleen M. Stacy

Dissertations

Nurses are faced with a multitude of clinical alarms on a daily basis. There is an inherent expectation that upon hearing an alarm the nurse will immediately respond to assess the situation and initiate appropriate action to correct the problem. Yet this does not always occur. Issues with alarm responsiveness can pose a serious threat to patient safety. The purpose of this qualitative study was to develop a broader understanding of the contextual factors that influenced the acute care nurse's response to clinical alarms. This study used an interpretive phenomenological methodology to study the lived experiences of the nurses who …

A Study To Determine The Relationships Among Grit, Engagement, And Student Achievement, Jill Dennison

Dissertations

In the absence of high quality and impact interventions, undesirable consequences of poverty will be seen to fruition. In this study, the Golden Circle business model (Sinek et al., 2017) served as the framework to understand how students’ grit, engagement, and achievement are related in Title I elementary schools. The purpose of this study was to determine if there is a relationship between grit and engagement, engagement and student achievement, and finally grit and student achievement. The relationship between grit and engagement was measured by teacher and student perceptions, respectively. Student engagement and achievement were analyzed using student self-perceptions of …

Leadership Behaviors Needed By Executive Directors Of Nonprofit Victim Support Organizations, Timothy Hunt

Dissertations

Purpose: The purpose of this mixed methods study was to determine how nonprofit victim support organization leaders rate the impact of the 10 Transformational Leadership Skills Inventory (TLSi) domains on their effectiveness. In addition, it was the purpose to discover how nonprofit victim support organization leaders describe the impact of each TLSi domain on their effectiveness.

Methodology: The participants in this study were executive directors of private, nonprofit victim support organizations across the Pacific Northwest region of Washington, Oregon, and Idaho. All participated in an online quantitative survey where they rated their agreement with statements about the impact of the …

Phenomenological Study On The Impact Of Servant Leadership For Establishing A Culture Of High Performance As Perceived By Public School District Superintendents, Robin Stout

Dissertations

Purpose: The purpose of this phenomenological study was to explore and describe K12 public school superintendents’ perceived impact of the seven servant leadership constructs established by Patterson (2003) on establishing a culture of high performance.

Methodology: This phenomenological research study identified and described the extent to which superintendents perceived the impact servant leadership has on establishing a culture of high performance. Eight participants were selected through non probability purposeful and convenience sampling based on specific criteria including a minimum of three years of experience at their current district and a minimum of five years of experience as a superintendent. The …

An Examination Of Indicators Regarding Student Choice In Social Media Marketing And Platforms Of Higher Education Institutions In Missouri, Emmy J. Zimmerman

Dissertations

The purpose of this study is to investigate relationships between social media marketing, social media platforms, and student choice of higher education institutions. Through evaluating current research, this study addresses potential changes needed to ensure colleges’ and universities’ marketing and admissions teams are using social media in ways that increase return on investment (ROI) and attract students to institutions. Previous research exposed social media marketing as a relatively untested method of reach for students’ college choice; therefore, the study will be original in nature. Previous studies provided data from an admissions counselor’s perspective, notably, a study by Barnes and Jacobsen …