Matching Items (43,917)
Description
To address sustainability issues in wastewater treatment (WWT), Siemens Water Technologies (SWT) has designed a "hybrid" process that couples common activated sludge (AS) and anaerobic digestion (AD) technologies with the novel concepts of AD sludge recycle and biosorption. At least 85% of the hybrid's AD sludge is recycled to the AS process, providing additional sorbent for influent particulate chemical oxygen demand (PCOD) biosorption in contact tanks. Biosorbed PCOD is transported to the AD, where it is converted to methane. The aim of this study is to provide mass balance and microbial community analysis (MCA) of SWT's two hybrid and one conventional pilot plant trains and mathematical modeling of the hybrid process including a novel model of biosorption. A detailed mass balance was performed on each tank and the overall system. The mass balance data supports the hybrid process is more sustainable: It produces 1.5 to 5.5x more methane and 50 to 83% less sludge than the conventional train. The hybrid's superior performance is driven by 4 to 8 times longer solid retention times (SRTs) as compared to conventional trains. However, the conversion of influent COD to methane was low at 15 to 22%, and neither train exhibited significant nitrification or denitrification. Data were inconclusive as to the role of biosorption in the processes. MCA indicated the presence of Archaea and nitrifiers throughout both systems. However, it is inconclusive as to how active Archaea and nitrifiers are under anoxic, aerobic, and anaerobic conditions. Mathematical modeling confirms the hybrid process produces 4 to 20 times more methane and 20 to 83% less sludge than the conventional train under various operating conditions. Neither process removes more than 25% of the influent nitrogen or converts more that 13% to nitrogen gas due to biomass washout in the contact tank and short SRTs in the stabilization tank. In addition, a mathematical relationship was developed to describe PCOD biosorption through adsorption to biomass and floc entrapment. Ultimately, process performance is more heavily influenced by the higher AD SRTs attained when sludge is recycled through the system and less influenced by the inclusion of biosorption kinetics.
Contributors
Young, Michelle Nichole (Author) / Rittmann, Bruce E. (Thesis advisor) / Fox, Peter (Committee member) / Krajmalnik-Brown, Rosa (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Cerebral palsy (CP) is a non-progressive neurologic disorder characterized by motor pathway damage prior to functional development. Damage to the central nervous system impairs motor functioning, including control of motor movement, loss of coordination, and loss of purposeful posture in individuals with cerebral palsy. This creates abnormal walking gait, impaired balance, and loss of muscle control. Current research shows positive results in studying the use of rhythmic music and walking gait for individuals with neurologic disorders. However, most research focuses on neurologic disorders acquired later in life, such as post-stroke patients and individuals with Parkinson's disease and traumatic brain injuries. The current study addresses the impact of rhythmic music on walking gait for an individual with cerebral palsy. Research addresses whether the use of rhythmic music impacts: (a) endurance (laps, distance traversed, and steps taken) (b) cadence (steps per minute), (c) velocity (distance over time), (d) emotional responsiveness (positive or negative affect), and (e) motivation. The current study is a single subject, mixed method design under randomized treatment conditions. The subject is a 25-year-old female diagnosed with spastic diplegic cerebral palsy. The subject participated in a five-week study, three times a week for one hour each session. Assessment was conducted during the first session. The following 14 sessions included gait training either under treatment (the use of recorded rhythmic music accompanied by audible drum beat) or control (no music) randomly assigned prior to the beginning of the study. Data were collected through video recordings, subject and researcher journals, and emotional responsiveness surveys. Data were analyzed for treatment versus control conditions. Analysis of both quantitative and qualitative data indicated that rhythmic music does impact walking gait for individuals with cerebral palsy. When compared to control conditions, the treatment conditions showed an increase in endurance, cadence, and velocity, and improvement in affect and motivation.
Contributors
Tindal, Sevrina (Author) / Crowe, Barbara (Thesis advisor) / Rio, Robin (Committee member) / Stauffer, Sandra (Committee member) / Arizona State University (Publisher)
Created
2011
Description
This thesis describes an approach to system identification based on compressive sensing and demonstrates its efficacy on a challenging classical benchmark single-input, multiple output (SIMO) mechanical system consisting of an inverted pendulum on a cart. Due to its inherent non-linearity and unstable behavior, very few techniques currently exist that are capable of identifying this system. The challenge in identification also lies in the coupled behavior of the system and in the difficulty of obtaining the full-range dynamics. The differential equations describing the system dynamics are determined from measurements of the system's input-output behavior. These equations are assumed to consist of the superposition, with unknown weights, of a small number of terms drawn from a large library of nonlinear terms. Under this assumption, compressed sensing allows the constituent library elements and their corresponding weights to be identified by decomposing a time-series signal of the system's outputs into a sparse superposition of corresponding time-series signals produced by the library components. The most popular techniques for non-linear system identification entail the use of ANN's (Artificial Neural Networks), which require a large number of measurements of the input and output data at high sampling frequencies. The method developed in this project requires very few samples and the accuracy of reconstruction is extremely high. Furthermore, this method yields the Ordinary Differential Equation (ODE) of the system explicitly. This is in contrast to some ANN approaches that produce only a trained network which might lose fidelity with change of initial conditions or if facing an input that wasn't used during its training. This technique is expected to be of value in system identification of complex dynamic systems encountered in diverse fields such as Biology, Computation, Statistics, Mechanics and Electrical Engineering.
Contributors
Naik, Manjish Arvind (Author) / Cochran, Douglas (Thesis advisor) / Kovvali, Narayan (Committee member) / Kawski, Matthias (Committee member) / Platte, Rodrigo (Committee member) / Arizona State University (Publisher)
Created
2011
Description
This dissertation is a comparative study of three contemporary women filmmakers: Puerto Rican Frances Negrón-Muntaner, Chicana director Lourdes Portillo, and Brazilian director Helena Solberg. Informed by transnational theory, politics of location, feminism on the border, and approaches to documentary filmmaking, the study examines three filmic texts: Brincando el charco: Portrait of a Puerto Rican (1994), The Devil Never Sleeps/El diablo nunca duerme (1994), and Carmen Miranda: Bananas Is My Business (1994). Each film is narrated by a female voice who juxtaposes her personal and transnational identity with history to tell her migration story before and after returning to her country of origin. An objective of the study is to demonstrate how the film directors vis-á-vis their female protagonists, configure a United States Latina transnational imaginary to position their female protagonists and themselves as female directors and as active social agents. Further, the dissertation explores how the filmmakers construct, utilizing the cinematographic apparatus, specific forms of resistance to confront certain oppressive forms. The theoretical framework proposes that transnational documentary filmmaking offers specific contestatory representations and makes possible the opening of parallel spaces in order to allow for a transformation from multiple perspectives. Through the utilization of specific techniques such as archival footage, the three directors focus on historical biographies. Further, they make use of experimental filmmaking and, in particular, the transnational documentary to deconstruct hegemonic discourses. Lastly, transnational cinema is valued as a field for cultural renegotiating and as a result, the documentary filmmakers in this study are able to reconfigure a transnational imaginary and propose an alternative discourse about history, sexuality, family structures, and gender relations. In sum, my dissertation contributes to Chicana/o and U.S. Latina/o, American Literature, and other Ethnic Literatures by focusing on migration, acculturation, and multicultural dialogue.
Contributors
Valenzuela Pulido, Norma A (Author) / Hernández-G, Manuel De Jesús (Thesis advisor) / Foster, David W. (Committee member) / Mcelroy, Isis (Committee member) / Sanchez, Marta (Committee member) / Elenes, C. Alejandra (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Many methods of passive flow control rely on changes to surface morphology. Roughening surfaces to induce boundary layer transition to turbulence and in turn delay separation is a powerful approach to lowering drag on bluff bodies. While the influence in broad terms of how roughness and other means of passive flow control to delay separation on bluff bodies is known, basic mechanisms are not well understood. Of particular interest for the current work is understanding the role of surface dimpling on boundary layers. A computational approach is employed and the study has two main goals. The first is to understand and advance the numerical methodology utilized for the computations. The second is to shed some light on the details of how surface dimples distort boundary layers and cause transition to turbulence. Simulations are performed of the flow over a simplified configuration: the flow of a boundary layer over a dimpled flat plate. The flow is modeled using an immersed boundary as a representation of the dimpled surface along with direct numerical simulation of the Navier-Stokes equations. The dimple geometry used is fixed and is that of a spherical depression in the flat plate with a depth-to-diameter ratio of 0.1. The dimples are arranged in staggered rows separated by spacing of the center of the bottom of the dimples by one diameter in both the spanwise and streamwise dimensions. The simulations are conducted for both two and three staggered rows of dimples. Flow variables are normalized at the inlet by the dimple depth and the Reynolds number is specified as 4000 (based on freestream velocity and inlet boundary layer thickness). First and second order statistics show the turbulent boundary layers correlate well to channel flow and flow of a zero pressure gradient flat plate boundary layers in the viscous sublayer and the buffer layer, but deviates further away from the wall. The forcing of transition to turbulence by the dimples is unlike the transition caused by a naturally transitioning flow, a small perturbation such as trip tape in experimental flows, or noise in the inlet condition for computational flows.
Contributors
Gutierrez-Jensen, Jeremiah J (Author) / Squires, Kyle (Thesis advisor) / Hermann, Marcus (Committee member) / Gelb, Anne (Committee member) / Arizona State University (Publisher)
Created
2011
Description
Consumer goods supply chains have gradually incorporated lean manufacturing principles to identify and reduce non-value-added activities. Companies implementing lean practices have experienced improvements in cost, quality, and demand responsiveness. However certain elements of these practices, especially those related to transportation and distribution may have detrimental impact on the environment. This study asks: What impact do current best practices in lean logistics and retailing have on environmental performance? The research hypothesis of this dissertation establishes that lean distribution of durable and consumable goods can result in an increased amount of carbon dioxide emissions, leading to climate change and natural resource depletion impacts, while lean retailing operations can reduce carbon emissions. Distribution and retailing phases of the life cycle are characterized in a two-echelon supply chain discrete-event simulation modeled after current operations from leading organizations based in the U.S. Southwest. By conducting an overview of critical sustainability issues and their relationship with consumer products, it is possible to address the environmental implications of lean logistics and retailing operations. Provided the waste reduction nature from lean manufacturing, four lean best practices are examined in detail in order to formulate specific research propositions. These propositions are integrated into an experimental design linking annual carbon dioxide equivalent emissions to: (1) shipment frequency between supply chain partners, (2) proximity between decoupling point of products and final customers, (3) inventory turns at the warehousing level, and (4) degree of supplier integration. All propositions are tested through the use of the simulation model. Results confirmed the four research propositions. Furthermore, they suggest synergy between product shipment frequency among supply chain partners and product management due to lean retailing practices. In addition, the study confirms prior research speculations about the potential carbon intensity from transportation operations subject to lean principles.
Contributors
Ugarte Irizarri, Gustavo Marco Antonio (Author) / Golden, Jay S. (Thesis advisor) / Dooley, Kevin J. (Thesis advisor) / Boone, Christopher G. (Committee member) / Basile, George M. (Committee member) / Arizona State University (Publisher)
Created
2011
Description
The marimba has garnered increased attention in percussion performance over the past thirty years. Literature for beginners through professionals in a multitude of styles have been written. With the ever-growing number of marimbists since the 1980's there has been a high demand for new works. Numerous pieces were created through commissions: composers contracted to write music by individuals, institutions, and consortia. Three primary types of marimba solo music were written: unaccompanied solos, concerti, and marimba solos with electronic accompaniment. Since electronic music is relatively new in marimba performance, there is very little information published regarding this topic. Only a handful of well-known compositions in this genre have been widely performed, and a great number of existing works are unfamiliar to the percussion world. The goal of this study is to generate an overview of electronic music in marimba performance by compiling a chronological catalog of compositions written for solo marimba with electronics. In addition, this study wishes to promote this genre of solo marimba music through the commission, performance, examination, and recording of a new work for marimba and electronics. It is the author's wish to bring this topic to percussionists' attention, and to enrich the marimba solo literature by both exploring existing literature and encouraging the commissioning and performance of marimba music.
Contributors
Chen, Yi-Chia (Author) / Smith, J.B. (Thesis advisor) / Bush, Jeffery (Committee member) / Hackbarth, Glenn (Committee member) / Hill, Gary (Committee member) / Sunkett, Mark (Committee member) / Arizona State University (Publisher)
Created
2011
Description
The purpose of this study was to analyze the impact of a context-based teaching approach (STS) versus a more traditional textbook approach on the attitudes and achievement of community college chemistry students. In studying attitudes toward chemistry within this study, I used a 30-item Likert scale in order to study the importance of chemistry in students' lives, the importance of chemistry, the difficulty of chemistry, interest in chemistry, and the usefulness of chemistry for their future career. Though the STS approach students had higher attitude post scores, there was no significant difference between the STS and textbook students' attitude post scores. It was noted that females had higher postattitude scores in the STS group, while males had higher postattitude scores in the textbook group. With regard to postachievement, I noted that males had higher scores in both groups. A correlation existed between postattitude and postachievement in the STS classroom. In summary, while an association between attitude and achievement was found in the STS classroom, teaching approach or sex was not found to influence attitudes, while sex was also not found to influence achievement. These results, overall, suggest that attitudes are not expected to change on the basis of either teaching approach or gender, and that techniques other than changing the teaching approach would need to be used in order to improve the attitudes of students. Qualitative analysis of an online discussion activity on Energy revealed that STS students were able to apply aspects of chemistry in decision making related to socioscientific issues. Additional analysis of interview and written responses provided insight regarding attitudes toward chemistry, with respect to topics of applicability of chemistry to life, difficulties with chemistry, teaching approach for chemistry, and the intent for enrolling in additional chemistry courses. In addition, the surveys of female students brought out subcategories with regard to emotional and professional characteristics of a good teacher, under the category of characteristics of teaching approach. With respect to the category of course experience, subcategories of useful knowledge to solve real-life problems and knowledge for future career were revealed. The differences between the control group females and STS group females with respect to these characteristics was striking and threw insight into how teacher behavior and teaching approach shape student attitudes to chemistry in case of female students.
Contributors
Perkins, Gita (Author) / Baker, Dale R. (Thesis advisor) / Sloane, Finbarr (Committee member) / Marsh, Josephine P (Committee member) / Arizona State University (Publisher)
Created
2011
Description
This dissertation explores the interrelationships between periods of rapid social change and regional-scale social identities. Using archaeological data from the Cibola region of the U.S. Southwest, I examine changes in the nature and scale of social identification across a period of demographic and social upheaval (A.D. 1150-1325) marked by a shift from dispersed hamlets, to clustered villages, and eventually, to a small number of large nucleated towns. This transformation in settlement organization entailed a fundamental reconfiguration of the relationships among households and communities across an area of over 45,000 km2. This study draws on contemporary social theory focused on political mobilization and social movements to investigate how changes in the process of social identification can influence the potential for such widespread and rapid transformations. This framework suggests that social identification can be divided into two primary modes; relational identification based on networks of interaction among individuals, and categorical identification based on active expressions of affiliation with social roles or groups to which one can belong. Importantly, trajectories of social transformations are closely tied to the interrelationships between these two modes of identification. This study has three components: Social transformation, indicated by rapid demographic and settlement transitions, is documented through settlement studies drawing on a massive, regional database including over 1,500 sites. Relational identities, indicated by networks of interaction, are documented through ceramic compositional analyses of over 2,100 potsherds, technological characterizations of over 2,000 utilitarian ceramic vessels, and the distributions of different types of domestic architectural features across the region. Categorical identities are documented through stylistic comparisons of a large sample of polychrome ceramic vessels and characterizations of public architectural spaces. Contrary to assumptions underlying traditional approaches to social identity in archaeology, this study demonstrates that relational and categorical identities are not necessarily coterminous. Importantly, however, the strongest patterns of relational connections prior to the period of social transformation in the Cibola region largely predict the scale and structure of changes associated with that transformation. This suggests that the social transformation in the Cibola region, despite occurring in a non-state setting, was governed by similar dynamics to well-documented contemporary examples.
Contributors
Peeples, Matthew A. (Author) / Kintigh, Keith W. (Thesis advisor) / Hegmon, Michelle (Thesis advisor) / Spielmann, Katherine A. (Committee member) / Arizona State University (Publisher)
Created
2011
Description
To sustain world preeminence, 21st century university and college leaders in the United States are redesigning their institutions organizationally and culturally to align with the direction of local and global societies and markets. The New American University enterprise model at Arizona State University has become one of the leading organization and cultural redesigns in United States higher education since its inception in 2002. Yet, sustaining a 21st century model such as this one means every individual in the college or university must understand his or her specific role to further progress the new model forward. Therefore, to advance and sustain a 21st century higher education redesign model at a U.S. college or university, it becomes imperative that every master-level professional who works in the academic/student services field at the institution understand his or her specific role in helping to further progress the new model forward. To this end, there is a need to change the way graduate students in higher education/student affairs masters programs are educated to work in the 21st century institution. This change can prepare new professionals to understand these enterprise models and how to integrate them into their practice in order to meet the needs of the institution, local and global societies and markets. The purpose of this action research study is to highlight one program, the ASU M.Ed. Higher and Postsecondary program, and show how graduates from 2007 - 2011 understand New American University concepts and integrate them into professional practice within higher education. Through use of a quantitative approach, this action research study described how the ASU M.Ed. in Higher and Postsecondary program graduate students' understanding of New American University concepts informs their thinking and practice to lead and respond to changes and challenges facing today's 21st century higher education field.
Contributors
Antonucci, Mark J (Author) / Ewing, Kris M (Thesis advisor) / Denke, Mark (Committee member) / Rund, James (Committee member) / Arizona State University (Publisher)
Created
2011