Matching Items (297)
Description
DNA is a unique, highly programmable and addressable biomolecule. Due to its reliable and predictable base recognition behavior, uniform structural properties, and extraordinary stability, DNA molecules are desirable substrates for biological computation and nanotechnology. The field of DNA computation has gained considerable attention due to the possibility of exploiting the massive parallelism that is inherent in natural systems to solve computational problems. This dissertation focuses on building novel types of computational DNA systems based on both DNA reaction networks and DNA nanotechnology. A series of related research projects are presented here. First, a novel, three-input majority logic gate based on DNA strand displacement reactions was constructed. Here, the three inputs in the majority gate have equal priority, and the output will be true if any two of the inputs are true. We subsequently designed and realized a complex, 5-input majority logic gate. By controlling two of the five inputs, the complex gate is capable of realizing every combination of OR and AND gates of the other 3 inputs. Next, we constructed a half adder, which is a basic arithmetic unit, from DNA strand operated XOR and AND gates. The aim of these two projects was to develop novel types of DNA logic gates to enrich the DNA computation toolbox, and to examine plausible ways to implement large scale DNA logic circuits. The third project utilized a two dimensional DNA origami frame shaped structure with a hollow interior where DNA hybridization seeds were selectively positioned to control the assembly of small DNA tile building blocks. The small DNA tiles were directed to fill the hollow interior of the DNA origami frame, guided through sticky end interactions at prescribed positions. This research shed light on the fundamental behavior of DNA based self-assembling systems, and provided the information necessary to build programmed nanodisplays based on the self-assembly of DNA.
ContributorsLi, Wei (Author) / Yan, Hao (Thesis advisor) / Liu, Yan (Thesis advisor) / Chen, Julian (Committee member) / Gould, Ian (Committee member) / Arizona State University (Publisher)
Created2014
Description
Because of its ability to harbor social values, norms, and beliefs, heritage has always been utilized as an ideological vehicle. One prominent example of politicizing heritage is Chinese red tourism, comprised of state-promoted tours to revolutionary memorial sites. It is expected to generate political, economic, and social benefits, particularly to reinforce the legitimate leadership of the Chinese Communist Party. Statistics show that dramatic market growth in red tourism has occurred over the past decade. Yet it is still heavily driven by the government and thus whether long-term sustainability can be achieved is still questionable.
This dissertation explores the dynamics of red tourism from the perspective of a meaning-making process, where tourism discourses circulate among the processes of production, transmission, and consumption. The results reveal that higher-level government primarily assumes the leading role, whereas local government is largely excluded from strategy making processes and primarily responsible for implementation and operation. Some dissonance exists between higher and lower-level governments in their goals and involvement in red tourism development. Second, intermediaries are not altruistic and attempt to maximize their own benefits. While site interpreters may provide officially authorized narratives, their primary focus is hosting higher-up administrative visitors. On the contrary, tour guides are more customer-oriented, which may lead to officially undesirable interpretations. Third, driven by multiple motives, tourists have increasingly diverse attitudes towards red heritage and participate in various political and non-political activities. A considerable degree of congruence was found between tourists' participation, motivation, memories, and perception. Quantitative results indicate that the majority of tourists have learned about the political significance and/or content of red heritage, and developed more positive attitudes towards, and support for, the CCP and the government, to a certain extent.
This dissertation contributes to current research by adopting a systematic and emic perspective to explore the dynamics of red tourism. Several conceptual frameworks were developed inductively to describe the meaning-making process. Mixed methods were used to learn about tourists' consumption and perceptions of red heritage. Implications regarding enhancing the effectiveness of the meaning-making process, limitations of the study, and potential directions for future research are also discussed.
This dissertation explores the dynamics of red tourism from the perspective of a meaning-making process, where tourism discourses circulate among the processes of production, transmission, and consumption. The results reveal that higher-level government primarily assumes the leading role, whereas local government is largely excluded from strategy making processes and primarily responsible for implementation and operation. Some dissonance exists between higher and lower-level governments in their goals and involvement in red tourism development. Second, intermediaries are not altruistic and attempt to maximize their own benefits. While site interpreters may provide officially authorized narratives, their primary focus is hosting higher-up administrative visitors. On the contrary, tour guides are more customer-oriented, which may lead to officially undesirable interpretations. Third, driven by multiple motives, tourists have increasingly diverse attitudes towards red heritage and participate in various political and non-political activities. A considerable degree of congruence was found between tourists' participation, motivation, memories, and perception. Quantitative results indicate that the majority of tourists have learned about the political significance and/or content of red heritage, and developed more positive attitudes towards, and support for, the CCP and the government, to a certain extent.
This dissertation contributes to current research by adopting a systematic and emic perspective to explore the dynamics of red tourism. Several conceptual frameworks were developed inductively to describe the meaning-making process. Mixed methods were used to learn about tourists' consumption and perceptions of red heritage. Implications regarding enhancing the effectiveness of the meaning-making process, limitations of the study, and potential directions for future research are also discussed.
ContributorsZhao, Shengnan (Author) / Timothy, Dallen J. (Thesis advisor) / Chhabra, Deepak (Committee member) / Lee, Woojin (Committee member) / Nyaupane, Gyan (Committee member) / Li, Wei (Committee member) / Arizona State University (Publisher)
Created2014
Description
The objective of this study was to understand domestic and foreign-born housekeeper's individual perceptions of labor mobility and job satisfaction related to their jobs within the hospitality industry. Literature regarding the bridging of tourism, immigration, and labor supply was addressed to expose broad conceptual frameworks that lead to the development of this study. More specifically, literature regarding labor mobility within tourism industries, migrant decision making, and barriers to mobility and immigration helped to construct a narrowed conceptual framework specific to hospitality labor in Phoenix, Arizona. Similar and previous studies focused on perceived labor mobility during significant economic or industry shifts. This study included the addition of a policy factor to help determine to what degree state policy change effected hospitality workers' perceived labor mobility. Arizona's recently passed and implemented legislative act SB1070 regards immigrant identification and employment, and enforcement of the act in the state of Arizona; this serves as the implicated policy change. Data were collected via on-site survey administered February to May 2011. An overall score was created for the five motivational dimensions: 1 — Status; 2 — Economic; 3 — Refugee; 4 — Entrepreneurial; and, 5 — Political using principle component factor analysis using a varimax rotation with Kaiser normalization. Theory and literature suggest that the economic advancement, status advancement, and the refugee orientation are effective explanatory variables for motivating a career move into the tourism industry. A total of 82 questionnaires were delivered and completed (N = 82), and none were eliminated. The statistically-determined Economic Dimension was characterized by eleven statements explained 51% of the variation and was the overwhelming motivational force. The average coded response for change in job satisfaction was very positive at .75. Ten features of changes in job satisfaction were used as the basis of the second measure of change in job satisfaction. The first Principle Component of the ten features of job satisfaction change explained 45% of the variation in these features and loadings were positive near or above 0.60 for all items. The relationship between variations in each of the measurements of change in job satisfaction and motivating factors was explored using regression analysis. The two dependent variables were Overall Change and First Principle Component, and the independent variables for both regressions included the four motivating factors as measured by the rotated factors scores to represent dimensions of Economic, Status, Refugee and Entrepreneurial. In addition to the motivational factors, four demographic variables were included as independent variables to account for personal and situational differences. None of the regression coefficients were significant at even the 10% level. Although this result was expected, the positive sign of regression coefficients suggest that expectations of working as a housekeepers results in a positive outcome. Understanding this relationship further is necessary, and seeking larger sample sizes over a longer period of time would be most beneficial to this field of research.
ContributorsCasson, Mallory (Author) / Tyrrell, Timothy (Thesis advisor) / Budruk, Megha (Committee member) / Li, Wei (Committee member) / Arizona State University (Publisher)
Created2011
Description
Engineering is a multidisciplinary field with a variety of applications. However, since there are so many disciplines of engineering, it is often challenging to find the discipline that best suits an individual interested in engineering. Not knowing which area of engineering most aligns to one’s interests is challenging when deciding on a major and a career. With the development of the Engineering Interest Quiz (EIQ), the goal was to help individuals find the field of engineering that is most similar to their interests. Initially, an Engineering Faculty Survey (EFS) was created to gather information from engineering faculty at Arizona State University (ASU) and to determine keywords that describe each field of engineering. With this list of keywords, the EIQ was developed. Data from the EIQ compared the engineering students’ top three results for the best engineering discipline for them with their current engineering major of study. The data analysis showed that 70% of the respondents had their major listed as one of the top three results they were given and 30% of the respondents did not have their major listed. Of that 70%, 64% had their current major listed as the highest or tied for the highest percentage and 36% had their major listed as the second or third highest percentage. Furthermore, the EIQ data was compared between genders. Only 33% of the male students had their current major listed as their highest percentage, but 55% had their major as one of their top three results. Women had higher percentages with 63% listing their current major as their highest percentage and 81% listing it in the top three of their final results.
ContributorsWagner, Avery Rose (Co-author) / Lucca, Claudia (Co-author) / Taylor, David (Thesis director) / Miller, Cindy (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
The impact of physical/chemical properties of gray water on microbial inactivation in gray water using chlorine was investigated through creating artificial gray water in lab, varying specific components, and then measuring microbial inactivation. Gray water was made through taking autoclaved nanopure water, and increasing the concentration of surfacants, the turbidity, the concentration of organic content, and spiking E. coli grown in tryptic soy broth (TSB); chlorine was introduced using Clorox Disinfecting Bleach2. Bacteria was detected using tryptic soy agar (TSA), and E. coli was specifically detected using the selective media, brilliance. The log inactivation of bacteria detected using TSA was shown to be inversely related to the turbidity of the solution. Complete inactivation of E. coli concentrations between 104-105 CFU/100 ml in gray water with turbidities between 10-100 NTU, 0.1-0.5 mg/L of humic acid, and 0.1 ml of Dawn Ultra, was shown to occur, as detected by brilliance, at chlorine concentrations of 1-2 mg/L within 30 seconds. These result in concentration time (CT) values between 0.5-1 mg/L·min. Under the same gray water conditions, and an E. coli concentration of 104 CFU/100 ml and a chlorine concentration of 0.01 mg/L, complete inactivation was shown to occur in all trials within two minutes. These result in CT values ranging from 0.005 to 0.02. The turbidity and humic acid concentration were shown to be inversely related to the log inactivation and directly related to the CT value. This study shows that chlorination is a valid method of treatment of gray water for certain irrigation reuses.
ContributorsGreenberg, Samuel Gabe (Author) / Abbaszadegan, Morteza (Thesis director) / Schoepf, Jared (Committee member) / Alum, Absar (Committee member) / Chemical Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Increasing energy and environmental problems describe the need to develop renewable chemicals and fuels. Global research has been targeting using microbial systems on a commercial scale for synthesis of valuable compounds. The goal of this project was to refactor and overexpress b6-f complex proteins in cyanobacteria to improve photosynthesis under dynamic light conditions. Improvement in the photosynthetic system can directly relate to higher yields of valuable compounds such as carotenoids and higher yields of biomass which can be used as energy molecules. Four engineered strains of cyanobacteria were successfully constructed and overexpressed the corresponding four large subunits in the cytochrome b6-f complex. No significant changes were found in cell growth or pigment titer in the modified strains compared to the wild type. The growth assay will be performed at higher and/or dynamic light intensities including natural light conditions for further analysis.
ContributorsNauroth, Benjamin (Author) / Varman, Arul (Thesis director) / Singharoy, Abhishek (Committee member) / Li, Han (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
This research investigated deionized water contact angle measurement reliability with alumina powder using the Washburn method. This method relates the capillary rise of a liquid through a column of packed powder to the contact angle of the system. A reference liquid that is assumed to be perfectly wetting, such as hexane due to the low surface energy, must be used to compare to the tested liquid. Consistency was hypothesized to be achieved with more powder structure and consistency of packing between reference and test trials. The three types of packing structures explored in this study were unstructured, visually-structured (user tapped), and machine-structured tapping. It was also hypothesized that similar contact angle results would be found for different packing methods of the same powder and liquid. However, the average contact angle for unstructured packing was found to be 32.9°, while the angle for the tapped structure was only 11.7°. This large deviation between types of packing shows that there are more inconsistencies with the use of this method than just the regulation of the packing structure. There were two similar glass chromatography columns used, but the second column experienced an unknown interference that led to a delay in the hexane uptake into the powder, which then led to invalid contact angle calculations. There was no discernible relationship between the packing structure and the standard deviation between trials, so the more structured packing does not seem to affect the consistency of results. It is recommended to perform more experiments on a single packing type with different apparatuses and a narrower particle size range.
ContributorsConvery, Brittany Alexis (Author) / Emady, Heather (Thesis director) / Vajrala, Spandana (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
The Experimental Data Processing (EDP) software is a C++ GUI-based application to streamline the process of creating a model for structural systems based on experimental data. EDP is designed to process raw data, filter the data for noise and outliers, create a fitted model to describe that data, complete a probabilistic analysis to describe the variation between replicates of the experimental process, and analyze reliability of a structural system based on that model. In order to help design the EDP software to perform the full analysis, the probabilistic and regression modeling aspects of this analysis have been explored. The focus has been on creating and analyzing probabilistic models for the data, adding multivariate and nonparametric fits to raw data, and developing computational techniques that allow for these methods to be properly implemented within EDP. For creating a probabilistic model of replicate data, the normal, lognormal, gamma, Weibull, and generalized exponential distributions have been explored. Goodness-of-fit tests, including the chi-squared, Anderson-Darling, and Kolmogorov-Smirnoff tests, have been used in order to analyze the effectiveness of any of these probabilistic models in describing the variation of parameters between replicates of an experimental test. An example using Young's modulus data for a Kevlar-49 Swath stress-strain test was used in order to demonstrate how this analysis is performed within EDP. In order to implement the distributions, numerical solutions for the gamma, beta, and hypergeometric functions were implemented, along with an arbitrary precision library to store numbers that exceed the maximum size of double-precision floating point digits. To create a multivariate fit, the multilinear solution was created as the simplest solution to the multivariate regression problem. This solution was then extended to solve nonlinear problems that can be linearized into multiple separable terms. These problems were solved analytically with the closed-form solution for the multilinear regression, and then by using a QR decomposition to solve numerically while avoiding numerical instabilities associated with matrix inversion. For nonparametric regression, or smoothing, the loess method was developed as a robust technique for filtering noise while maintaining the general structure of the data points. The loess solution was created by addressing concerns associated with simpler smoothing methods, including the running mean, running line, and kernel smoothing techniques, and combining the ability of each of these methods to resolve those issues. The loess smoothing method involves weighting each point in a partition of the data set, and then adding either a line or a polynomial fit within that partition. Both linear and quadratic methods were applied to a carbon fiber compression test, showing that the quadratic model was more accurate but the linear model had a shape that was more effective for analyzing the experimental data. Finally, the EDP program itself was explored to consider its current functionalities for processing data, as described by shear tests on carbon fiber data, and the future functionalities to be developed. The probabilistic and raw data processing capabilities were demonstrated within EDP, and the multivariate and loess analysis was demonstrated using R. As the functionality and relevant considerations for these methods have been developed, the immediate goal is to finish implementing and integrating these additional features into a version of EDP that performs a full streamlined structural analysis on experimental data.
ContributorsMarkov, Elan Richard (Author) / Rajan, Subramaniam (Thesis director) / Khaled, Bilal (Committee member) / Chemical Engineering Program (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Ira A. Fulton School of Engineering (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The wettability of powders is an important characteristic for both industry and academia and is often described by the powder’s contact angle with a certain liquid. While there exist many ways to measure contact angle, it is a portion of the powder technology field that is not fully understood and requires more investigation and research. This study investigates two methods for measuring contact angle, the sessile drop method and the Washburn method, and looks to compare results to determine which method offers the most reliable data in terms of accuracy and repeatability. Two powders - microcrystalline cellulose and aluminum oxide - and three liquids - water, 50 cSt silicone oil, and 350 cSt silicone oil - were used to study the differences between the two measurement techniques as well as the effects of varying fluid viscosity on the measurements. It was found that the sessile drop method proved to be an ineffective method for measuring contact angle when liquid penetration into the powder occurred, as the contact angle changed while the drop penetrated. Initial results showed the contact angle for silicone oil on the powders to be greater than 90°, indicating nonwetting of the surface which was inconsistent with observations. The results from the Washburn method align better with other values in similar studies, but more study is needed to confirm the results gathered in this research.
ContributorsSmith, Bryan Alexander (Author) / Emady, Heather (Thesis director) / Rykaczewski, Konrad (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
With each new Disney princess being hailed as finally representing a strong, positive female role model, the images presented by older princesses come into question. This investigation delves into the messages put forth by the Disney princess films and the way in which these ideas are developed within each of their movies. By defining the core of feminism to revolve around agency and the freedom of choice available to the women in the films, each princess' adherence to feminist values was analyzed. All current and expected Disney princesses were evaluated (Snow White, Cinderella, Aurora, Ariel, Belle, Jasmine, Pocahontas, Mulan, Tiana, Rapunzel, Merida, Anna, and Elsa). The princesses were split into five categories to offer comparison and conclusions between women with similar characteristics: the Traditionals, the Dreamers, the Adventurers, the Rebels, and the Non-Conformists. Major findings include the evolution of the marriage ideal presented by Disney, the issue between race and labor within the princess franchise, and the amount of agency each princess is allowed in her movie. Disney presents many stories where the individual wishes of a princess class with her society or community, but not all princesses are successful in going against their cultural values. A majority of the princesses do exercise their agency in their films, but this is done with varying degrees of freedom and choices available to them. Disney's representation of traditional love stories has slowly evolved, now allowing women to pursue other dreams concurrently with romance, or even dreams entirely devoid of love. Disney has also made an effort to branch out with princesses of color and from other cultures, yet these films often end up presenting a cultural critique as opposed to a feminist critique of gender roles. The franchise also seems to present labor as a form of oppression which white princesses must escape while princesses of color do not receive the same respite or salvation at the end of their films. White princesses end with a life of luxury and relaxation that isn't afforded to Disney's princesses of color. Though there is much room for improvement with future Disney princess films, the past princesses are not necessarily as "anti-feminist" as they have been portrayed. Each princess exhibits more autonomy and agency than the last, providing more paths and options for young girls to consider as they grow up watching these films.
ContributorsFerrero Mendoza, Vanessa Cristina (Author) / Dove-Viebahn, Aviva (Thesis director) / Kitch, Sally (Committee member) / Chemical Engineering Program (Contributor) / School of International Letters and Cultures (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05