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This study examines the experiences of parents in mixed marriages (Vietnamese married to non-Vietnamese) raising their children in the United States. Specifically, this study focused on what factors influence parents' development of family language policies and patterns of language use. While research has been done on language policy and planning at the macro-level and there are an increasing number of studies on family language policy at the microlevel, few studies have focused on couples in mixed marriages who are heritage language speakers of the language they are trying to teach their children. This study used both surveys and interviews to gather data about parents' beliefs and attitudes towards bilingualism and the heritage language (HL), strategies parents are using to teach their children the HL, and major challenges they face in doing so. There were three main findings. First, parents without full fluency in the HL nevertheless are able to pass the HL on to their children. Second, an important factor influencing parents' family language policies and patterns of language use were parents' attitudes towards the HL--specifically, if parents felt it was important for their children to learn the HL and if parents were willing to push their children to do so. Third, proximity to a large Vietnamese community and access to Vietnamese resources (e.g., Vietnamese language school, Vietnamese church/temple, etc.) did not assure families' involvement in the Vietnamese community or use of the available Vietnamese resources. The findings of this study reveal that though language shift is occurring in these families, parents are still trying to pass on the HL to their children despite the many challenges of raising them bilingually in the U.S.
ContributorsLam, Ha (Author) / Wiley, Terrence (Thesis advisor) / Appleton, Nicholas (Thesis advisor) / Tobin, Joseph (Committee member) / Arizona State University (Publisher)
Created2011
Description
ABSTRACT In Roosevelt v. Bishop (1994), Arizona public school districts and parents challenged Arizona's school financing system arguing that it was not "general and uniform" as required by the Arizona Constitution. The purpose of this study was to analyze Arizona's Students Fair and Immediate Resources for Students Today (Students FIRST) legislation, the remedy that resulted from the Roosevelt decision, empirically, and longitudinally. Three types of statistical analyses were conducted on a sample of 165 public school districts. Fiscal neutrality was measured for each of the eleven years of the study, to assess the association between the per-pupil Students FIRST funding level and the per-pupil property wealth. Multiple regression analysis was also conducted to assess if both property wealth and district size were associated with the distribution of Students FIRST funding. Finally, I analyzed the eleven-year average of the total Students FIRST funding distributed to school districts and assessed how the plaintiff districts ranked in the distribution. Overall, the findings revealed that Students FIRST met the fiscal neutrality standard in some, but not in all the categories and years of this study, per-pupil property wealth was only weakly related to, and district size was not associated with, Students FIRST funding. The analysis of average funding suggested that some property rich school districts benefited most from Students FIRST. These results suggest that the traditional measures used to assess the fiscal neutrality of operating funding may not be appropriate for assessing the fiscal neutrality of capital finance reforms. While the results of this study provide some suggestive evidence that Students FIRST did not fulfill the Court's mandate, additional research is needed as to whether or not Arizona's capital finance system has resulted in disparities in funding that fall short of the constitutional standard.
ContributorsBaca, Kenneth R (Author) / Powers, Jeanne M. (Thesis advisor) / Garcia, David R. (Committee member) / Essigs, Chuck (Committee member) / Arizona State University (Publisher)
Created2011
Description
Dye sensitized solar cells (DSSCs) are the third generation solar cells expected to outperform the first two generations of solar cells with their advantages of comparative higher efficiency and lower manufacturing costs. The manufacturing cost of Dye sensitized solar cells is one fifth of the conventional silicon solar cell. However, DSSCs have problems of low conversion efficiency, stability and reliability. Some effective approaches are required to improve their performance. This paper projects the work related to assessment and verification of the repeatability of the semi-automated fabrication process. Changes were introduced in to the fabrication process to enhance the efficiency and stability. The sealant step in the fabrication process was remodeled to a newer version with an improvement in efficiency from 11% to 11.8%. Sputtering was performed on counter electrode in 30 seconds intervals. Cells were fabricated to assess the performance & time dependent characteristics from EIS experiments. Series resistance increased three times in sputtered Pt electrode as compared to standard platinum electrode. This resulted in the degradation of conductive surface on glass electrode due to heavy bombardment of ions. The second phase of the project work relates to the incorporation of SWCNT on the TiO2 electrode and its effect on the cell efficiency. Different weight loadings (0.1 wt %, 0.2 wt%, 0.4 wt %) of SWCNTs were prepared and mixed with the commercial TiO2 paste and ethanol solvent. The TiO2-SWCNT layer was coated on the electrode using screen-printing technique. Both open circuit voltage and photocurrent were found to have measurable dependence on the TiO2 layer loading. Photo voltage ranged from ~0.73 V to ~0.43 V and photocurrent from ~8 to ~33 mA depending on weight percent loading. This behavior is due to aggregation of particles and most TiO2 aggregate particles are not connected to SWCNT. Transparency loss was observed leading to saturation in the photo current and limiting the light absorption within the TiO2 film.
ContributorsKinhal, Kartik (Author) / Munukutla, Lakshmi V (Thesis advisor) / Subach, James (Committee member) / Peng, Xihong (Committee member) / Arizona State University (Publisher)
Created2011
Description
Demands in file size and transfer rates for consumer-orientated products have escalated in recent times. This is primarily due to the emergence of high definition video content. Now factor in the consumer desire for convenience, and we find that wireless service is the most desired approach for inter-connectivity. Consumers expect wireless service to emulate wired service with little to virtually no difference in quality of service (QoS). The background section of this document examines the QoS requirements for wireless connectivity of high definition video applications. I then proceed to look at proposed solutions at the physical (PHY) and the media access control (MAC) layers as well as cross-layer schemes. These schemes are subsequently are evaluated in terms of usefulness in a multi-gigabit, 60 GHz wireless multimedia system targeting the average consumer. It is determined that a substantial gap in published literature exists pertinent to this application. Specifically, little or no work has been found that shows how an adaptive PHYMAC cross-layer solution that provides real-time compensation for varying channel conditions might be actually implemented. Further, no work has been found that shows results of such a model. This research proposes, develops and implements in Matlab code an alternate cross-layer solution that will provide acceptable QoS service for multimedia applications. Simulations using actual high definition video sequences are used to test the proposed solution. Results based on the average PSNR metric show that a quasi-adaptive algorithm provides greater than 7 dB of improvement over a non-adaptive approach while a fully-adaptive alogrithm provides over18 dB of improvement. The fully adaptive implementation has been conclusively shown to be superior to non-adaptive techniques and sufficiently superior to even quasi-adaptive algorithms.
ContributorsBosco, Bruce (Author) / Reisslein, Martin (Thesis advisor) / Tepedelenlioğlu, Cihan (Committee member) / Sen, Arunabha (Committee member) / Arizona State University (Publisher)
Created2011
Description
In this thesis the performance of a Hybrid AC System (HACS) is modeled and optimized. The HACS utilizes solar photovoltaic (PV) panels to help reduce the demand from the utility during peak hours. The system also includes an ice Thermal Energy Storage (TES) tank to accumulate cooling energy during off-peak hours. The AC runs continuously on grid power during off-peak hours to generate cooling for the house and to store thermal energy in the TES. During peak hours, the AC runs on the power supplied from the PV, and cools the house along with the energy stored in the TES. A higher initial cost is expected due to the additional components of the HACS (PV and TES), but a lower operational cost due to higher energy efficiency, energy storage and renewable energy utilization. A house cooled by the HACS will require a smaller size AC unit (about 48% less in the rated capacity), compared to a conventional AC system. To compare the cost effectiveness of the HACS with a regular AC system, time-of-use (TOU) utility rates are considered, as well as the cost of the system components and the annual maintenance. The model shows that the HACS pays back its initial cost of $28k in about 6 years with an 8% APR, and saves about $45k in total cost when compared to a regular AC system that cools the same house for the same period of 6 years.
ContributorsJubran, Sadiq (Author) / Phelan, Patrick (Thesis advisor) / Calhoun, Ronald (Committee member) / Trimble, Steve (Committee member) / Arizona State University (Publisher)
Created2011
Description
ABSTRACT The behavior of the fission products, as they are released from fission events during nuclear reaction, plays an important role in nuclear fuel performance. Fission product release can occur through grain boundary (GB) at low burnups; therefore, this study simulates the mass transport of fission gases in a 2-D GB network to look into the effects of GB characteristics on this phenomenon, with emphasis on conditions that can lead to percolation. A finite element model was created based on the microstructure of a depleted UO2 sample characterized by Electron Backscattering Diffraction (EBSD). The GBs were categorized into high (D2), low (D1) and bulk diffusivity (Dbulk) based on their misorientation angles and Coincident Site Lattice (CSL) types. The simulation was run using different diffusivity ratios (D2/Dbulk) ranging from 1 to 10^8. The model was set up in three ways: constant temperature case, temperature gradient effects and window methods that mimic the environments in a Light Water Reactor (LWR). In general, the formation of percolation paths was observed at a ratio higher than 10^4 in the measured GB network, which had a 68% fraction of high diffusivity GBs. The presence of temperature gradient created an uneven concentration distribution and decreased the overall mass flux. Finally, radial temperature and fission gas concentration profiles were obtained for a fuel pellet in operation using an approximate 1-D model. The 100 µm long microstructurally explicit model was used to simulate, to the scale of a real UO2 pellet, the mass transport at different radial positions, with boundary conditions obtained from the profiles. Stronger percolation effects were observed at the intermediate and periphery position of the pellet. The results also showed that highest mass flux happens at the edge of a pellet at steady state to accommodate for the sharp concentration drop.
ContributorsLim, Harn Chyi (Author) / Peralta, Pedro (Thesis advisor) / Dey, Sandwip (Committee member) / Sieradzki, Karl (Committee member) / Arizona State University (Publisher)
Created2011
Description
Filtration for microfluidic sample-collection devices is desirable for sample selection, concentration, preprocessing, and downstream manipulation, but microfabricating the required sub-micrometer filtration structure is an elaborate process. This thesis presents a simple method to fabricate polydimethylsiloxane (PDMS) devices with an integrated membrane filter that will sample, lyse, and extract the DNA from microorganisms in aqueous environments. An off-the-shelf membrane filter disc was embedded in a PDMS layer and sequentially bound with other PDMS channel layers. No leakage was observed during filtration. This device was validated by concentrating a large amount of cyanobacterium Synechocystis in simulated sample water with consistent performance across devices. After accumulating sufficient biomass on the filter, a sequential electrochemical lysing process was performed by applying 5VDC across the filter. This device was further evaluated by delivering several samples of differing concentrations of cyanobacterium Synechocystis then quantifying the DNA using real-time PCR. Lastly, an environmental sample was run through the device and the amount of photosynthetic microorganisms present in the water was determined. The major breakthroughs in this design are low energy demand, cheap materials, simple design, straightforward fabrication, and robust performance, together enabling wide-utility of similar chip-based devices for field-deployable operations in environmental micro-biotechnology.
ContributorsLecluse, Aurelie (Author) / Meldrum, Deirdre (Thesis advisor) / Chao, Joseph (Thesis advisor) / Westerhoff, Paul (Committee member) / Arizona State University (Publisher)
Created2011
Description
As the demand for power increases in populated areas, so will the demand for water. Current power plant technology relies heavily on the Rankine cycle in coal, nuclear and solar thermal power systems which ultimately use condensers to cool the steam in the system. In dry climates, the amount of water to cool off the condenser can be extremely large. Current wet cooling technologies such as cooling towers lose water from evaporation. One alternative to prevent this would be to implement a radiative cooling system. More specifically, a system that utilizes the volumetric radiation emission from water to the night sky could be implemented. This thesis analyzes the validity of a radiative cooling system that uses direct radiant emission to cool water. A brief study on potential infrared transparent cover materials such as polyethylene (PE) and polyvinyl carbonate (PVC) was performed. Also, two different experiments to determine the cooling power from radiation were developed and run. The results showed a minimum cooling power of 33.7 W/m2 for a vacuum insulated glass system and 37.57 W/m2 for a tray system with a maximum of 98.61 Wm-2 at a point when conduction and convection heat fluxes were considered to be zero. The results also showed that PE proved to be the best cover material. The minimum numerical results compared well with other studies performed in the field using similar techniques and materials. The results show that a radiative cooling system for a power plant could be feasible given that the cover material selection is narrowed down, an ample amount of land is available and an economic analysis is performed proving it to be cost competitive with conventional systems.
ContributorsOvermann, William (Author) / Phelan, Patrick (Thesis advisor) / Trimble, Steve (Committee member) / Taylor, Robert (Committee member) / Arizona State University (Publisher)
Created2011
Description
One of the critical imperatives for the development of inclusive school systems is the capacity to nurture and develop teachers who have the skills, critical sensibilities, and the contextual awareness to provide quality educational access, participation, and outcomes for all students; however, research on teacher learning for inclusive education has not yet generated a robust body of knowledge to understand how teachers become inclusive teachers in institutions where exclusion is historical and ubiquitous. Drawing from socio-cultural theory, this study aimed to fill this gap through an examination of teacher learning for inclusive education in an urban professional learning school. In particular, I aimed to answer the following two questions: (a) What social discourses are present in a professional learning school for inclusive education?, and (b) How do teachers appropriate these social discourses in situated practice? I used analytical tools from Critical Discourse Analysis (CDA) and Grounded Theory to analyze entry and exit interviews with teacher residents, principals, site professors, and video-stimulated interviews with teacher residents, observations of classroom practices and thesis seminars, and school documents. I found two social discourses that I called discourses of professionalism, as they offered teachers a particular combination of tools, aiming to universalize certain tools for doing and thinking that signaled what it meant to be a professional teacher in the participating schools. These were the Total Quality Management like discourse (TQM-like) and the Inclusive Education-like discourse. The former was dominant in the schools, whereas the latter was dominant in the university Master's program. These discourses overlapped in teachers' classrooms practices, creating tensions. To understand how these tensions were resolved, this study introduced the concept of curating, a kind of heuristic development that pertains particularly to the work achieved in boundary practices in which individuals must claim multiple memberships by appropriating the discourses and their particular tool kits of more than one community of practice. This study provides recommendations for future research and the engineering of professional development efforts for inclusive education.
ContributorsWaitoller, Federico R. (Author) / Artiles, Alfredo J. (Thesis advisor) / Kozleski, Elizabeth B. (Committee member) / Gee, James P (Committee member) / Arizona State University (Publisher)
Created2011
Description
Michael Apple's scholarship on curriculum, educational ideology, and official knowledge continues to be influential to the study of schooling. Drawing on the sociological insights of Pierre Bourdieu and the cultural studies approaches of Raymond Williams, Apple articulates a theory of schooling that pays particular attention to how official knowledge is incorporated into the processes of schooling, including textbooks. In an effort to contribute to Apple's scholarship on textbooks, this study analyzed high school American history textbooks from the 1960s through the 2000s with specific attention to the urban riots of the late-1960s, sixties counterculture, and the women's movement utilizing Julia Kristeva's psychoanalytic concept of abjection to augment Apple's theory of knowledge incorporation. This combination reveals not only how select knowledge is incorporated as official knowledge, but also how knowledge is treated as abject, as unfit for the curricular body of official knowledge and the selective tradition of American history. To bridge the theoretical frameworks of incorporation and abjection Raymond Williams' theory of structures of feeling and Slavoj iek's theory of ideological quilting are employed to show how feelings and emotional investments maintain ideologies. The theoretical framework developed and the interpretive analyses undertaken demonstrate how textbook depictions of these historical events structure students' present educational experiences with race, class, and gender.
ContributorsKearl, Benjamin (Author) / Margolis, Eric (Thesis advisor) / Blumenfeld-Jones, Donald (Committee member) / Sandlin, Jennifer (Committee member) / Arizona State University (Publisher)
Created2011