Digital Commons Network^™

Modeling Contaminant Transport And Fate And Subsequent Impacts On Ecosystems, Ming Fan

Dissertations

Assessing risks associated with the release of metals into the environment and managing remedial activities requires simulation tools that depict speciation and risk with accurate mechanistic models and well-defined transport parameters. Such tools need to address the following processes: (1) aqueous speciation, (2) distribution mechanisms, (3) transport, and (4) ecological risk. The primary objective of this research is to develop a simulation tool that accounts for these processes. Speciation in the aqueous phase can be assessed with geochemical equilibrium models, such as MINEQL+. Furthermore, metal distribution can be addressed mechanistically. Studies with Pb sorption to amorphous aluminum (HAG), iron (HFO), …

Modeling Usage Of An Online Research Community, Yi Zhang

Dissertations

Although online communities have been thought of as a new way for collaboration across geographic boundaries in the scientific world, they have a problem attracting people to keep visiting. The main purpose of this study is to understand how people behave in such communities, and to build and evaluate tools to stimulate engagement in a research community. These tools were designed based on a research framework of factors that influence online participation and relationship development.

There are two main objectives for people to join an online community, information sharing and interpersonal relationship development, such as friends or colleagues. The tools …

Toxicity Of Manufactured Particulate Materials On Plant Root Growth, Ling Yang

Dissertations

The rapid development of particle technology and the growing use of particulate materials in industries are bringing large amounts of manufactured particles into the environment. Epidemiological studies suggest that fine particles (particles with aerodynamic diameter smaller than 2.5 μm, i.e., PM_2.5) have an association with various adverse health effects in humans. Mass studies have been performed on the toxicity and toxicological mechanisms of airborne particles such as PM_2.5 and PM₁₀, but there are very few investigations which contribute to the knowledge base on biological implications of manufactured particulate materials. Up to now, the published toxicity …

Finding Meaning By Participating In Decisions Affecting Us, Our Work And Our Lives: Lessons Learned At Mondragón, David Herrera Edd

Dissertations

There has been a growing interest in exploring participatory organizational models for the last fifty years, accentuated by the recent corporate scandals that revealed the inadequacies of non-participatory organizational systems. Research studies have focused on organizational structures, policies and practices that make participation possible but it is persons who make participation happen. The purpose of this study was therefore to explore the significance of participation by examining the question: What does the experience of partaking in decision making mean to persons who engage in it. This research is a phenomenological-heuristic study. Phenomenology explores the lived experience of participating in decision …

Language Interactions Between Reading Recovery Teachers And Their English-Language Learners, Leslie Yerington Edd

Dissertations

This qualitative study investigated characteristics of student-teacher interactions during the new book introduction portion of Reading Recovery lessons. The new book introduction provides the student with background knowledge and story plot sufficient to render a successful first attempt reading the book that takes place directly after the introduction. The purpose of this study was to investigate the characteristics of student-teacher interactions during the new book introduction portion of Reading Recovery lessons in order to describe the nature of these interactions and discover the relationships, if any exist, between the interactions and student performance. The study also searched for common themes …

Examining The Meaning And Experience Of Self-Determination And Its Impact On Quality Of Life For Individuals With Cognitive Disabilities, Carol Marie Sundberg

Dissertations

There is a national agenda for advancing self-determination for persons with disabilities. Broadly defined, self-determination means having control over ones own life. The purpose of this research was to gain a better understanding of self-determination and its effect on the quality of life of persons with cognitive disabilities. A qualitative, phenomenological approach was selected. Ten individuals from a community mental health system in southwest Michigan participated in the study. Participants had a developmental disability and were dependent on others for their care. The research combined qualitative interviews with behavioral observations and proxy interviewing, and included the audiotaping of those interviews. …

From Violence-Prone To Violence-Prepared Organizations Assessing The Role Of Human Resources Management In Preventing Workplace Violence In American City Governments, Saleh Abdel Rahman Ahmed

Dissertations

Violence is a significant occupational hazard in the American workplace. Nearly a thousand employees are murdered on the job each year and workplacehomicide has become the leading cause of death for women and the second for men. From 1993 to 1999, there were an average of 1.7 million nonfatal violent victimizations each year, accounting for 18% of all violent crime. Although government employees accounted for 18% of the U.S. workforce, they made up 37% of workplace violence victims.

A review of literature found no unified definition of workplace violence. Recent scientific research regarding this problem is rare, despite its increasing …

Patriarch Nikon's Image In Russian History And Culture, Kevin Kain

Dissertations

This dissertation investigates representations of Nikon, Patriarch of Moscow and all Russia (1652-1666). I contend that Nikon's resonance in Russian national life remains largely unrecognized because traditional histories--based entirely on written sources and limited to Nikon's tenure as Patriarch--fail to reveal his broader significance in Russian artistic, political and religious culture by omitting analysis of art and material culture. This dissertation advances the study of Patriarch Nikon by assessing his image in Russian history and culture from the mid-seventeenth century forward. I demonstrate that contrary to his overwhelmingly negative image in standard histories, the Patriarch held a central place in …

Exploring The Relationship Between Race-Related Stress, Identity And Well-Being Among African Americans, Darrick Tovar-Murray

Dissertations

For almost four hundred years, African Americans have been victims of race-related stress. Race-related stress is defined as the encounters between individuals and their environment that surface from racism and strain an individual's resources or threaten his or her well-being. Despite findings on the negative impact of racism on African Americans' well-being, very little research has focused on the relationships between race-related stress, identity and well-being among African Americans.

The purpose of this study was to explore the relationships between race-related stress, identity, and well-being among African Americans. A total of 196 African American community members and college students participated …

Electronic Literacy: Teaching Literary Reading Through The Digital Medium, Robert Adams Rozema

Dissertations

Over the last decade, digital technology has become an increasingly important part of education. In the discipline of English language arts, digital technology has been enlisted to teach writing, as the word processor and more recently, the World Wide Web, have provided new tools and new publishing opportunities for student writers. The presence of digital technology is less pronounced, however, in literature instruction in secondary schools. In both theoretical and practical discussions of digital technology and literature, the two mediums have been conceived as radically different. This dissertation argues that the digital medium, and more specifically the World Wide Web, …

Negative Stereotypes And Childhood Paternal Relationships As Predictors Of Paternal Identity In African American Fathers, Danielle K. Wright

Dissertations

African American men have been widely ignored in the social science literature. When African American men have been studied, it has primarily been from a deficit model. The purpose of this study was to give voice to the African American father, whether he is working-poor, middle-class, or upper-class, biological or non-biological, residential or non-residential. The intent of the study was to explore how African American men view themselves as fathers and their own experiences of being a parent.

One hundred and one men who identified as African American, were at least 18 years old, and who had at least one …

Differentiation Of The Causal Characteristics And Influences Of Virtual Reality And The Effects On Learning At A Science Exhibit, Arlene De Strulle Edd

Dissertations

Within the context of the informal science center, exhibits are the main interface for public learning. Essential to the success of a science center is how well exhibits model effective strategies for learning. Virtual Reality (VR) technology with its flexible, adaptive, multimedia, and immersive-learning capabilities is emerging for use by science centers in exhibits; however, research on learning in virtual environments at exhibits is scarce. To support the future development of VR science exhibits it is critical to investigate VR's pedagogical value and effects on science learning. Research investigated the Smoke & Mirrors VR exhibit at the Reuben H. Fleet …

What Kinds Of Adolescent Leaders Are Hiding In Newbery Books?, Carol Jasperse Lautenbach

Dissertations

Though adolescent leadership is worth developing, often it is not addressed effectively in the general middle school curriculum. This study addresses adolescent leadership by describing and discussing eight major leadership categories and 38 subcategories found in seventeen representative Newbery Award-winning books. The sample was chosen using a multiple-step process and contained fictional stories with adolescent protagonists in realistic situations. Content analysis was used to quantify and analyze the leadership themes; a code book was used to organize data. Occurrence of each sub-category was ranked for prevalence within each book. These rankings form the basis for the analysis of findings which …

Counselors’ Perceptions Of The Effectiveness Of Career Education Programs In Assisting High School Students When Making Career Decisions, Sandra L. Roberts Standish

Dissertations

In 1997, the Michigan Department of Career Development unveiled the Michigan Career Preparation System, which provided guidelines and funds for school districts to offer career education opportunities for students. Since high school counselors are oftentimes viewed as the primary provider of careerinformation to students, this study examined their perceptions of Michigan's Career Preparation System and the impact this initiative has had on studentsand educators. To gather this information, a 13-question survey was designed and distributed to a randomly selected group of high school counselors. Theresearch also provided a framework for understanding all of the components of both the Michigan Comprehensive …

The Social Construction Of Rape Research: Exploring Epistemologies And Evaluating Methods, Edith M. Fisher

Dissertations

The most widely known national study of rape found that one in four college-age women has been the victim of rape or attempted rape. Conservative writers have criticized that study for overestimating the possible prevalence of rape in the U.S. My research uses more sensitive instruments and administration techniques, seeking to estimate the prevalence of rape in the lives of women at a large midwestern public university. I address questions about the validity of previous rape research and compare methods of collecting sexual violence information by questionnaire (322 mailed surveys and 300 interviewer-administered surveys). Additional interviews with 62 of the …

The Politics Of Hiv/Aids And Implications For Democracy In Kenya, Wambuii Henry Kiragu

Dissertations

Democratic consolidation in newly transitioned democracies has traditionally been attributed to widely accepted political and legal mechanisms, like elections and constitutions. Existing literature on democratization in sub-Saharan Africa is preoccupied with these mechanisms as prime indicators for democratic takeoff in specific countries. Hardly any attention has been paid to other less openly political mechanisms, such as the response to external shocks, as potential sources of institutional development that could advance democratic practices.

Yet national response to any external shock can entail a host of actions with potentially far ranging political implications, including transformation of the form and means of political …

Child Welfare And Devolving Federalism: An Analysis Of The Effects Of Federal Funding Schemes On Selected Child Welfare Outcomes In Michigan, Timothy J. Kangas

Dissertations

Child abuse and neglect has become a pervasive problem across the United States. Between 1985 and 1995 the foster care population in the United States grew by 79%, with costs soaring into the billions. During the mid-1990s, in an effort to address this issue, the federal government shifted from using a funding scheme identified with a traditional model of federalism to one identified with devolving federalism. In Michigan, the focus of this research, this shift in approaches occurred through the issuance of block grant funding for child welfare programming. The intent of this shift was to decentralize elements of the …

Official Discourse And Public Opinion In Post-Communist Societies: The Role Of Government-Affiliated Intellectuals, Ekaterina M. Levintova

Dissertations

Post-Communist countries are unique in the sense that they are undergoing not a single, but multiple transitions. The extent of social change underway inthis region is truly monumental and researchers are faced with the daunting task of studying the extent of this transformation. Change is most evident when one studies formal institutions. But lies beneath, on the level of value orientations? The answer to this question helps us understand the real progress of post-Communist countries towards the goals of their transitions.

What were the political, ideological, economic, foreign policy, and ethnic relations attitudes of the post-Communist Russian and Polish elites …

Girls And Science: A Qualitative Study On Factors Related To Success And Failure In Science, Paula Denise Johnson

Dissertations

This qualitative study sought to determine how girls perceived factors that contribute to their success in science programs designed to maximize their achievement. The sample consisted of 20 students in 9th and 12th grades attending a school of choice. Respondents were interviewed using a structured interview protocol.

The National Council for Research on Women study (Thom, 2001) found that girls are more successful in math and science programs that incorporate acooperative, hands-on approach than in programs that stress competition and individual learning. This finding was supported by this study among 20 high school girls in a school whose mission is …

Understanding The Origin Of The Recovery Of Superconductivity In Halogenated Ybco Single Crystal : Atomic Structure Study, Lamine Mohamed Kollakoye Dieng

Dissertations

The recovery of superconductivity in underdoped YBa₂Cu₃O_6+y (YBCO) by exposure to bromine, iodine, chlorine and fluorine is a long-standing problem which has not been clearly resolved. The key question concerns the role of these halogens in the lattice. In order to shed light to this problem, we have performed multiple-edge x-ray absorption fine structure (XAFS) measurements about the Y K, Ba L₃, I L₃, Cu K and Br K-edges at room temperature on brominated (non-brominated) and iodinated (non-iodinated) YBCO single crystals. Our XAFS results at the Br K (brominated) and I …

On Ip Over Wdm Burst-Switched Long Haul And Metropolitan Area Networks, Jingxuan Liu

Dissertations

The IP over Wavelength Division Multiplexing (WDM) network is a natural evolution ushered in by the phenomenal advances in networking technologies and technical breakthroughs in optical communications, fueled by the increasing demand in the reduction of operation costs and the network management complexity. The unprecedented bandwidth provisioning capability and the multi-service supportability of the WDM technology, in synergy with the data-oriented internetworking mechanisms, facilitates a common shared infrastructure for the Next Generation Internet (NGJ).

While NGI targets to perform packet processing directly on the optical transport layer, a smooth evolution is critical to success. Intense research has been conducted to …

Studies Of Disk Arrays Tolerating Two Disk Failures And A Proposal For A Heterogeneous Disk Array, Chunqi Han

Dissertations

There has been an explosion in the amount of generated data in the past decade. Online access to these data is made possible by large disk arrays, especially in the RAID (Redundant Array of Independent Disks) paradigm. According to the RAID level a disk array can tolerate one or more disk failures, so that the storage subsystem can continue operating with disk failure(s). RAID 5 is a single disk failure tolerant array which dedicates the capacity of one disk to parity information. The content on the failed disk can be reconstructed on demand and written onto a spare disk. However, …

Providing Guaranteed Qos In The Hose-Modeled Vpn, Dong Wei

Dissertations

With the development of the Internet, Internet service providers (ISPs) are required to offer revenue-generating and value-added services instead of only providing bandwidth and access services. Virtual Private Network (VPN) is one of the most important value-added services for ISPs.

The "classical" VPN service is provided by implementing layer 2 technologies, either Frame Relay (FR) or Asynchronous Transfer Mode (ATM). With FR or ATM, virtual circuits are created before data delivery. Since the bandwidth and buffers are reserved, the QoS requirements can be naturally guaranteed. In the past few years, layer 3 VPN technologies are widely deployed due to the …

Ad Hoc Network Security And Modeling With Stochastic Petri Nets, Congzhe Zhang

Dissertations

Advances in wireless technology and portable computing along with demands for high user mobility have provided a major promotion toward the development of ad hoc networks. These networks feature dynamic topology, self-organization, limited bandwidth and battery power of a node. Unlike the existing commercial wireless systems and fixed infrastructure networks, they do not rely on specialized routers for path discovery and traffic routing. Security is an important issue in such networks. Typically, mobile nodes are significantly more susceptible to physical attacks than their wired counterparts.

This research intends to investigate the ad hoc network routing security by proposing a performance …

Uncertainty Analysis In Ecological Risk Assessment Modeling, Tepwitoon Thongsri

Dissertations

A probabilistic approach employing Monte Carlo simulations for assessing parameter and risks as probabilistic distributions was used in an ecological risk assessment (ERA) model to characterize risk and address uncertainty. This study addresses the following sources of uncertainty: parameter inputs in the ERA models, risk algorithms and uncertain input concentrations. To achieve this objective, both sensitivity and uncertainty analyses are being conducted. Monte Carlo simulations were used for generating probabilistic distributions of parameter and model uncertainty. All sensitivity, uncertainty, and variability analyses were coded in Visual Basic as part of the ERA model software version 2001, which was developed under …

Qos Provisioning In Multimedia Streaming, Hong Zhao

Dissertations

Multimedia consists of voice, video, and data. Sample applications include video conferencing, video on demand, distance learning, distributed games, and movies on demand. Providing Quality of Service (QoS) for multimedia streaming has been a difficult and challenging problem. When multimedia traffic is transported over a network, video traffic, though usually compressed/encoded for bandwidth reduction, still consumes most of the bandwidth. In addition, compressed video streams typically exhibit highly variable bit rates as well as long range dependence properties, thus exacerbating the challenge in meeting the stringent QoS requirements of multimedia streaming with high network utilization. Dynamic bandwidth allocation in which …

Hybrid Routing And Bridging Strategies For Large Scale Mobile Ad Hoc Networks, Sheng Xu

Dissertations

Multi-hop packet radio networks (or mobile ad-hoc networks) are an ideal technology to establish "instant" communication infrastructure for military and civilian applications in which both hosts and routers are mobile. In this dissertation, a position-based/link-state hybrid, proactive routing protocol (Position-guided Sliding-window Routing - PSR) that provides for a flat, mobile ad-hoc routing architecture is described, analyzed and evaluated. PSR is based on the superposition of link-state and position-based routing, and it employs a simplified way of localizing routing overhead, without having to resort to complex, multiple-tier routing organization schemes. A set of geographic routing zones is defined for each node, …

Webquest Design Strategies: A Case Study Measuring The Effect Of The Jigsaw Method On Students’ Personal Agency Beliefs, Engagement, And Learning, James P. Frazee Edd

Dissertations

The WebQuest model continues to grow in popularity, with teachers from around the world and many teacher-educators and experts in the field of educational technology espousing its potential to extend content knowledge and promote higher level thinking. While the model is well received by teachers and students alike, most evidence of its effectiveness is anecdotal, and there is very little in the way of empirical research on the elements that make an effective WebQuest. Furthermore, rich descriptions of how students interact during a well-developed WebQuest are largely absent from the literature. In short, the WebQuest model suffers from a lack …

Academic Performance, Persistence, And Cultural Congruence Of African American Males Attending Predominantly White Colleges And Universities, Darrell Johnson

Dissertations

The continued lack of success for African American males attending predominantly White colleges and universities is alarming and unsettling. Other racial minority groups are making positive gains relative to their post-secondary educational experiences. However, the African American male lags behind in virtually every index of success in higher education. This trend could produce serious social, economic and cultural implications for the African American community and the entire country.

For African Americans, a strong sense of culture is important to their ability to achieve high levels of mental and psychological functioning, particularly in environments they perceive to be hostile or unwelcoming. …

Studies Of Atomic And Molecular Dynamics Using Photoelectron Spectroscopy, Sophie E. Canton

Dissertations

Photoexcitation and photoionization studies of free atoms and molecules in the gas phase provide a unique view into various aspects of radiation-matter interactions that are used as basic building blocks in many branches of physics, such as Solid State, Plasma Physics, Photochemistry or Astrophysics. With the advent of third generation synchrotron light sources delivering high photon flux (>10¹⁵ photons/s) with unprecedented resolving power over a broad energy range, it has become possible to investigate in great detail not only the internal structure of the targets, but also the dynamics of the process. Born in the 1960s,photoelectron spectroscopy specifically …