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Learning in an online jazz history class

Description

This study examines the experiences of participants enrolled in an online community college jazz history course. I surveyed the participants before the course began and observed them in the online space through the duration of the course. Six students also participated in interviews during and after the course. Coded data from the interviews, surveys, and recorded discussion posts and journal entries provided evidence about the nature of interaction and engagement in learning in an online environment. I looked for evidence either supporting or detracting from a democratic online learning environment, concentrating on the categories of student engagement, freedom of expression, and accessibility. The data suggested that the participants' behaviors in and abilities to navigate the online class were influenced by their pre-existing native media habits. Participants' reasons for enrolling in the online course, which included convenience and schedule flexibility, informed their actions and behaviors in the class. Analysis revealed that perceived positive student engagement did not contribute to a democratic learning environment but rather to an easy, convenient experience in the online class. Finally, the data indicated that participants' behaviors in their future lives would not be affected by the online class in that their learning experiences were not potent enough to alter or inform their behavior in society. As online classes gain popularity, the ability of these classes to provide meaningful learning experiences must be questioned. Students in this online jazz history class presented, at times, a façade of participation and community building but demonstrated a lack of sincerity and interest in the course. The learning environment supported accessibility and freedom of expression to an extent, but students' engagement with their peers was limited. Overall, this study found a need for more research into the quality of online classes as learning platforms that support democracy, student-to-student interaction, and community building.

ContributorsHunter, Robert W. (Author) / Stauffer, Sandra L (Thesis advisor) / Tobias, Evan (Thesis advisor) / Bush, Jeffrey (Committee member) / Kocour, Michael (Committee member) / Pilafian, Sam (Committee member) / Arizona State University (Publisher)

Created2011

Utilization of thermoplastic mounting studs for simple performance testing on hot mix asphalt

Description

The objective of the research is to test the use of 3D printed thermoplastic to produce fixtures which affix instrumentation to asphalt concrete samples used for Simple Performance Testing (SPT). The testing is done as part of materials characterization to obtain properties that will help in future pavement designs. Currently, these fixtures (mounting studs) are made of expensive brass and cumbersome to clean with or without chemicals.

Three types of thermoplastics were utilized to assess the effect of temperature and applied stress on the performance of the 3D printed studs. Asphalt concrete samples fitted with thermoplastic studs were tested according to AASHTO & ASTM standards. The thermoplastics tested are: Polylactic acid (PLA), the most common 3D printing material; Acrylonitrile Butadiene Styrene (ABS), a typical 3D printing material which is less rigid than PLA and has a higher melting temperature; Polycarbonate (PC), a strong, high temperature 3D printing material.

A high traffic volume Marshal mix design from the City of Phoenix was obtained and adapted to a Superpave mix design methodology. The mix design is dense-graded with nominal maximum aggregate size of ¾” inch and a PG 70-10 binder. Samples were fabricated and the following tests were performed: Dynamic Modulus |E*| conducted at five temperatures and six frequencies; Flow Number conducted at a high temperature of 50°C, and axial cyclic fatigue test at a moderate temperature of 18°C.

The results from SPT for each 3D printed material were compared to results using brass mounting studs. Validation or rejection of the concept was determined from statistical analysis on the mean and variance of collected SPT test data.

The concept of using 3D printed thermoplastic for mounting stud fabrication is a promising option; however, the concept should be verified with more extensive research using a variety of asphalt mixes and operators to ensure no bias in the repeatability and reproducibility of test results. The Polycarbonate (PC) had a stronger layer bonding than ABS and PLA while printing. It was recommended for follow up studies.

ContributorsBeGell, Dirk (Author) / Kaloush, Kamil (Thesis advisor) / Mamlouk, Michael (Committee member) / Stempihar, Jeffery (Committee member) / Arizona State University (Publisher)

Created2018

A study of heating and degradation of acrylonitrile-butadiene-styrene/polycarbonate polymer due to ultraviolet lasers illumination during localized pre-deposition heating for fused filament fabrication 3D printing

Description

With the growing popularity of 3d printing in recreational, research, and commercial enterprises new techniques and processes are being developed to improve the quality of parts created. Even so, the anisotropic properties is still a major hindrance of parts manufactured in this method. The goal is to produce parts that mimic the strength characteristics of a comparable part of the same design and materials created using injection molding. In achieving this goal the production cost can be reduced by eliminating the initial investment needed for the creation of expensive tooling. This initial investment reduction will allow for a wider variant of products in smaller batch runs to be made available. This thesis implements the use of ultraviolet (UV) illumination for an in-process laser local pre-deposition heating (LLPH). By comparing samples with and without the LLPH process it is determined that applied energy that is absorbed by the polymer is converted to an increase in the interlayer temperature, and resulting in an observed increase in tensile strength over the baseline test samples. The increase in interlayer bonding thus can be considered the dominating factor over polymer degradation.

ContributorsKusel, Scott Daniel (Author) / Hsu, Keng (Thesis advisor) / Sodemann, Angela (Committee member) / Kannan, Arunachala M (Committee member) / Arizona State University (Publisher)

Created2017