Matching Items (182)
Description
This project is part of a larger project involving making membranes for the separation of potable water from urine solutions for applications in space travel. This project deals specifically with testing LTA nanozeolites that will be used in the membrane under a variety of acidic conditions, specifically in solutions of sulfuric acid, chromium trioxide, and potassium phosphate of pHs ranging from .5 to 5, in order to investigate the effects of pH, acid type, and time. They were analyzed using SEM, FTIR, and XRD, in order to analyze how much the zeolite was degraded under the conditions of each solution. It was determined that, for high pH values (4-5), potassium phosphate had the strongest effect, as it degraded the zeolite to the point of destroying the crystal structure completely. Because of the solubility limit of potassium phosphate in water, it could not be analyzed at low pH, so only sulfuric acid and chromium trioxide were analyzed at low pH (.5-3). They both had severe effects, sulfuric acid being slightly more severe, with both of them completely dissolving the zeolite at pH values of 1 and lower. Decreasing pH increased degradation for all of the acids, with pH values above 2 for sulfuric acid and chromium trioxide showing only minor degradation, and pH 5 potassium phosphate showing only minor degradation.
ContributorsWaller, Aaron Christopher (Author) / Lind, Mary Laura (Thesis director) / Dai, Lenore (Committee member) / Lin, Jerry (Committee member) / Barrett, The Honors College (Contributor)
Created2013-05
Description
Asymmetric polystyrene-gold composite particles are successfully synthesized alongside core-shell composite particles via a one-step Pickering emulsion polymerization method. Unlike core-shell particles which form in the droplet phase of a stabilized Pickering emulsion, asymmetric particles form via a seeded growth mechanism. These composite particles act as catalysts with higher recyclability than pure gold nanoparticles due to reduced agglomeration. With the addition of N-isopropylacrylamide (NIPAAM) monomers, temperature-responsive asymmetric and core-shell polystyrene/poly(N-isopropylacrylamide)-gold composite particles are also synthesized via Pickering emulsion polymerization. The asymmetric particles have a greater thermo-responsiveness than the core-shell particles due to the increased presence of NIPAAM monomers in the seeded-growth formation. Poly(N-isopropylacrylamide) (PNIPAM)-containing asymmetric particles have tunable rheological and optical properties due to their significant size decrease above the lower critical solution temperature (LCST).
ContributorsRabiah, Noelle Ibrahim (Author) / Dai, Lenore (Thesis director) / Torres, Cesar (Committee member) / Zhang, Mingmeng (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2014-05
Description
Abstract As we move forward in education reform in the globalized 21st century, the United States must visit new ways to teach science in high school classrooms. The goal of this investigation is to analyze the current research literature for the best and most promising teaching strategies and techniques in secondary education biology classrooms that promote academic excellence for all students. Looking at policy and school reform literature in science education to establish the context of the current system, the paper will not focus on the political as or systematic changes needed to ground an overall successful system. However, because of their inherent effect on the education system, the political aspects of education reform will be briefly addressed. The primary focus, by addressing the emphasis on standardization, inflexibility of instruction and lack of creativity specifically in high school biology classrooms, seeks to clarify small changes that can influence students' academic outcomes. The United States is performing on such a poor level in science and math proficiency that it cannot match students abroad and this is seen through test scores and the production of competent graduates. This investigation serves to organize literature from education researchers and showcase best and promising teaching and learning practices that catalyze academic excellence for all students in our pluralistic, democratic and complex schooling and societal contexts.
ContributorsHildebrandt, Kevin Andrew (Author) / Ovando, Carlos (Thesis director) / Schugurensky, Daniel, 1958- (Committee member) / Fischman, Gustavo (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of International Letters and Cultures (Contributor)
Created2013-05
Description
This study examined the quality of professional life at a Title I school that has achieved the Arizona Department of Education's highest accountability rating of Excelling for eight consecutive years. By examining the factors that influence the school environment including teachers' attitudes and the connections within the teacher community at this school, a description emerged of the factors that influenced the quality of professional lives of teachers. This descriptive study sought to describe, "What is the quality of professional life for teachers at a Title I elementary school with a history of high levels of student achievement?" The research was conducted at Seneca Elementary school (a pseudonym) in the Seneca School District (a pseudonym). By examining the quality of professional life for teachers in a highly ranked Title I school, a better understanding of the quality of professional life may lead to recommendations for other schools with high levels of poverty on how to support teachers who work in high poverty schools. Within a theoretical framework of motivation-hygiene theory and socio cultural theory, the study identified principal leadership as a primary supporting factor of quality of professional life. The study also identified lack of input and lack of teacher control over curriculum and instruction as barriers to quality of professional life. Teachers described principal leadership, environment, social factors and teacher identity as contributors to enhancing the quality of professional life. Trust and focus emerged as additional factors that improved the workplace for teachers.
ContributorsThomas, Jeffrey J (Author) / Danzig, Arnold (Thesis advisor) / Fischman, Gustavo (Committee member) / Boyle, Charlotte (Committee member) / Arizona State University (Publisher)
Created2011
Description
Amine-modified solid sorbents and membrane separation are promising technologies for separation and capture of carbon dioxide (CO2) from combustion flue gas. Amine absorption processes are mature, but still have room for improvement. This work focused on the synthesis of amine-modified aerogels and metal-organic framework-5 (MOF-5) membranes for CO2 separation. A series of solid sorbents were synthesized by functionalizing amines on the surface of silica aerogels. This was done by three coating methods: physical adsorption, magnetically assisted impact coating (MAIC) and atomic layer deposition (ALD). CO2 adsorption capacity of the sorbents was measured at room temperature in a Cahn microbalance. The sorbents synthesized by physical adsorption show the largest CO2 adsorption capacity (1.43-1.63 mmol CO2/g). An additional sorbent synthesized by ALD on hydrophilic aerogels at atmospheric pressures shows an adsorption capacity of 1.23 mmol CO2/g. Studies on one amine-modified sorbent show that the powder is of agglomerate bubbling fluidization (ABF) type. The powder is difficult to fluidize and has limited bed expansion. The ultimate goal is to configure the amine-modified sorbents in a micro-jet assisted gas fluidized bed to conduct adsorption studies. MOF-5 membranes were synthesized on α-alumina supports by two methods: in situ synthesis and secondary growth synthesis. Characterization by scanning electron microscope (SEM) imaging and X-ray diffraction (XRD) show that the membranes prepared by both methods have a thickness of 14-16 μm, and a MOF-5 crystal size of 15-25 μm with no apparent orientation. Single gas permeation results indicate that the gas transport through both membranes is determined by a combination of Knudsen diffusion and viscous flow. The contribution of viscous flow indicates that the membranes have defects.
ContributorsRosa, Teresa M (Author) / Lin, Jerry (Thesis advisor) / Pfeffer, Robert (Thesis advisor) / Dai, Lenore (Committee member) / Nielsen, David (Committee member) / Arizona State University (Publisher)
Created2010
Description
This paper presents a multiscale modeling approach to simulating the self-sensing behavior of a load sensitive smart polymer material. A statistical spring-bead based network model is developed to bridge the molecular dynamics simulations at the nanoscale and the finite element model at the macroscale. Parametric studies are conducted on the developed network model to investigate the effects of the thermoset crosslinking degree on the mechanical response of the self-sensing material. A comparison between experimental and simulation results shows that the multiscale framework is able to capture the global mechanical response with adequate accuracy and the network model is also capable of simulating the self-sensing phenomenon of the smart polymer. Finally, the molecular dynamics simulation and network model based simulation are implemented to evaluate damage initiation in the self-sensing material under monotonic loading.
ContributorsZhang, Jinjun (Author) / Koo, Bonsung (Author) / Liu, Yingtao (Author) / Zou, Jin (Author) / Chattopadhyay, Aditi (Author) / Dai, Lenore (Author) / Ira A. Fulton Schools of Engineering (Contributor) / School for the Engineering of Matter, Transport and Energy (Contributor)
Created2015-08-01
Description
Identification of early damage in polymer composites is of great importance. We have incorporated cyclobutane-containing cross-linked polymers into an epoxy matrix, studied the effect on thermal and mechanical properties, and, more importantly, demonstrated early damage detection through mechanically induced fluorescence generation. Two cinnamate derivatives, 1,1,1-tris(cinnamoyloxymethyl) ethane (TCE) and poly(vinyl cinnamate) (PVCi), were photoirradiated to produce cyclobutane-containing polymer. The effects on the thermal and mechanical properties with the addition of cyclobutane-containing polymer into epoxy matrix were investigated. The emergence of cracks was detected by fluorescence at a strain level just beyond the yield point of the polymer blends, and the fluorescence intensified with accumulation of strain. Overall, the results show that damage can be detected through fluorescence generation along crack propagation.
ContributorsZou, Jin (Author) / Liu, Yingtao (Author) / Shan, Bohan (Author) / Chattopadhyay, Aditi (Author) / Dai, Lenore (Author) / Ira A. Fulton Schools of Engineering (Contributor) / School for the Engineering of Matter, Transport and Energy (Contributor)
Created2014-09-01
Description
Participatory Budgeting (PB) can create changes within individuals and between them and their community. PB processes allow people to determine how to spend a portion of a particular budget (in the case of School PB, a portion of the school budget). These processes help address the underrepresentation of youth in the realm of civics.
I spent time with the steering committee and teacher coordinator of school PB in Carson Junior High to explore the impact of school PB on students’ knowledge, skills, attitudes and practices in relation to civic engagement. In the study I used quantitative and qualitative components. The participants were unique in that they all had prior experience in civic engagement programs in Carson Junior High that were organized by the teacher coordinator of school PB.
The main findings suggest that the participants reported a significant amount of learning in civic knowledge. In comparison, their overall perceived growth in attitudes, practices and skills were much lower. School PB helped the participants in the steering committee to grow in different ways than their other civic engagement programs by providing them with knowledge about budgets, their school’s mechanisms and other students within their school. They also became more familiar with the democratic process of voting and more comfortable with public speaking and presenting.
Recommendations for future research on this process include compiling quantitative and qualitative data from a larger sample consisting of students who had prior civic engagement experience and students who didn’t, and students with different ethnicities from different grades. Another recommendation for future research is to conduct a longitudinal study following school PB participants to high school and beyond to explore long-term impacts.
ContributorsKinzle, Lauren (Author) / Schugurensky, Daniel, 1958- (Thesis director) / Fischman, Gustavo (Committee member) / Barrett, The Honors College (Contributor) / Dean, W.P. Carey School of Business (Contributor)
Created2019-05
Description
Evidence of Six Sigma principles dates back as far as the 1800s when normal distributions were first being introduced by Friedrich Gauss. Since then, Six Sigma has evolved and been documented into the Define, Measure, Analyze, Improve, and Control (DMAIC) methodology that is used today. Each stage in the DMAIC methodology serves a unique purpose, and various tools have been developed to accomplish each stage’s goal. The manufacturing industry has developed its own more specified set of methods and tools that have been coined as Lean Six Sigma. The more notable Lean Six Sigma principles are TIMWOOD, SMED, and 5S.
As a case study, DMAIC methodology was used at a company that encourages Six Sigma in all its departments—Niagara Bottling. Ultimately, the company was able to cut its financial losses in fines from customers by over 15% in just a 12-week span by utilizing Six Sigma. In this, the importance of instilling an entire culture of Six Sigma is exemplified. When only a handful of team members are on board with the problem-solving mindset, it is significantly more difficult to see substantial improvements.
As a case study, DMAIC methodology was used at a company that encourages Six Sigma in all its departments—Niagara Bottling. Ultimately, the company was able to cut its financial losses in fines from customers by over 15% in just a 12-week span by utilizing Six Sigma. In this, the importance of instilling an entire culture of Six Sigma is exemplified. When only a handful of team members are on board with the problem-solving mindset, it is significantly more difficult to see substantial improvements.
ContributorsHumphreys, Nicholas Michael (Author) / Dai, Lenore (Thesis director) / Lin, Wendy (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Ionic liquids are salts with low melting temperatures that maintain their liquid form below 100 °C, or even at ambient temperature. Ionic liquids are conductive, electrochemically stable, non-volatile, and have a low vapor pressure, making them a class of excellent candidate materials for electrolytes in energy storage, electrodeposition, batteries, fuel cells, and supercapacitors. Due to their multiple advantages, the use of ionic liquids on Earth has been widely studied; however, further research must be done before their implementation in space. The extreme temperatures encountered during space travel and extra-terrestrial deployment have the potential to greatly affect the liquid electrolyte system. Examples of low temperature planetary bodies are the permanently shadowed sections of the moon or icy surfaces of Jupiter’s moons. Recent studies have explored the limits of glass transition temperatures for ionic liquid systems. The project is centered around the development of an ionic liquid system for a molecular electronic transducer seismometer that would be deployed on the low temperature system of Europa. For this project, molecular dynamics simulations used input intermolecular and intramolecular parameters that then simulated molecular interactions. Molecular dynamics simulations are based around the statistical mechanics of chemistry and help calculate equilibrium properties that are not easily calculated by hand. These simulations will give insight into what interactions are significant inside a ionic liquid solution. The simulations aim to create an understanding how ionic liquid electrolyte systems function at a molecular level. With this knowledge one can tune their system and its contents to adapt the systems properties to fit all environments the seismometers will experience.
ContributorsDavis, Vincent Champneys (Author) / Dai, Lenore (Thesis director) / Gliege, Marisa (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05