Additive manufacturing (AM) provides unique opportunities to push the boundaries of material properties and free form fabrication. However with this novel manufacturing technique a number of defects not commonly found in conventional processes such as machining or casting can arise. Both experimental and numerical studies can help better understand the printed material on a more fundamental level in order to optimize the process and mitigate these defects. Electron microscopy can provide essential information about the as-built microstructure and characteristic defects while numerical modelling can help determine a correlation between process parameters and the resulting properties. First, an initial investigation of directed energy deposition (DED) processed 4140 steel was conducted using various microscopy methods to better understand the defects and microstructure of the printed alloy. A martensite dominate microstructure within a bainitic matrix with increasing degrees of tempering further down the build was revealed. Additional sample preparation was conducted with a focused ion beam and analyzed with the transmission electron microscope to investigate features such as grain boundaries, mechanical twins and interplanar spacing. This interplanar spacing was measured for a number of different diffraction images and compared with the theoretical values. The deviation between the measured and theoretical values can be attributed to defects such as residual stress which causes lattice strain and consequently a smaller or larger spacing between atomic planes. Lastly, diffraction images were characterized and compared with the literature to determine the Miller indices and the specific zone axis orientations. A thermo-mechanical-metallurgical finite element model for 42CrMo4 steel was then developed in ABAQUS to identify the correlation between processing parameters and resulting properties by predicting the temperature history, and resulting residual stresses and metallurgical phase fractions for the DED process. A pre-processing framework was implemented in order to allow the modelling of complex geometries and laser trajectories while experiments were conducted to validate the fidelity of the model. Four separate cases were fabricated with varying processing parameters and geometries. In addition to in-situ temperature measurements, post-build residual stress and substrate distortion data was also collected. Furthermore, metallurgical analysis was performed for each case and compared with the simulated phase fractions. The accuracy of the distortion profile increased with increasing dwell time while the accuracy in predicting the metallurgical phase fractions and residual stresses demonstrated the opposite trend. / Graduate / 2022-07-05

Infants of various ages across the first postnatal year have shown behavioral preferences (i.e., more attention) to visual displays when looking resulted in the presentation of Infant-Directed Speech (IDS) compared to Adult-Directed Speech (ADS). Although IDS differs from ADS on a variety of measures, most research has focused on various pitch characteristics (i.e., IDS is higher in absolute pitch and more variable in pitch across utterance length). Work from our lab has found that when the pitch characteristics of IDS were held constant, but the temporal features were manipulated, younger (but not older) infants attended more to slower rates of IDS, even though it was unlikely that they had heard such speech (when speech is spoken at this slow rate, the fundamental frequency cannot be maintained). The purpose of this study was to expand our investigation of how speaking rate affects infant attention by adding the physiological measure of heart rate to our protocol. Of specific interest was whether infants would show differential amounts of heart-rate (HR) decelerations as a function of rate (i.e. greater decelerations to slowed speech). 4-month-old infants were tested with normal IDS (unaltered rate) and slow IDS (rate was twice as slow as normal). Behaviorally, infants did not differentially attend to a display as a function of speech type. Psychophysiologically, infants showed more pronounced HR decelerations to slow than to normal IDS. The discrepancy between measures of attention is discussed, especially with regard to the organization of attention in infants of this age. / Master of Science

Indiana University-Purdue University Indianapolis (IUPUI) / Ongoing changes to medical education curricula in the United States require continued evaluation of best practices for maintaining and enhancing anatomical education in medical schools. The purpose of this study was to identify the impacts of incorporating an alternating dissection schedule, peer teaching, and self-directed learning (SDL) in the Human Gross Anatomy (A550-551) laboratory for students in the first year of medical school at Indiana University School of Medicine, Bloomington (IUSM-BL). The researcher sought to determine the impacts of peer teaching and dissection on student gross anatomy grades, to explore the underling perceived effects of peer teaching on the student gross anatomy experience, and to explain how a gross anatomy course, specifically the laboratory component, could contribute to the development of SDL. A mixed method design was selected to combine the analytic strengths of quantitative and qualitative methods. Quantitative analysis using a generalized estimating equation determined the act of dissection had an impact on students’ abilities to correctly identify structures on human gross anatomy assessments. An analysis of variance determined that student gross anatomy final grades, lecture exam averages, laboratory practical exam averages were unchanged when incorporating peer teaching and alternating dissections into the laboratory sessions. A grounded theory methodology identified perceived changes in the student experience in A550-551 through analysis of student interviews, instructor interviews, and course assignments. In conclusion, the researcher determined that active dissection is a critical component in gross anatomy; however, peer teaching and alternating dissections offset the negative impacts of reduced dissections hours through: increased active dissection time, decreased intragroup conflict, new opportunities to develop teaching and communication skills, and increased efficiency in the anatomy laboratory classroom. Additionally, this research described suggestions for future successful implementations of SDL in A5500-551. These findings provide information for educators at IUSM-BL as they make revisions to meet curricular demands and inform ongoing discussions in anatomy education related to the importance of dissection, time for laboratory experiences, and the continued goal for excellence in educating students.

This project is an attempt to design a new English curriculum to fit a major organizational and philosophical change planned for Westmount Secondary School in the year 1990. Chapter 1 describes the context in which the innovation will take place, the nature of the innovation itself and the primary objective the changes is intended to fulfil; namely, the development of students who are self-directed problem-solvers. Chapter 2 attempts to clarify this objective by examining the origins of problem-solving in education and describing some recent accounts of its use, most notably in problem-based learning. Chapter 3 explores the philosophy of self-directed learning and differentiates among the many similar related terms. Autonomy is identified as the key feature of self-directed learning. Chapter 4 outlines the constraints on curriculum design imposed by the new English Guideline recently published by the Ministry of Education. Finally, in chapter 5 an attempt is made to identify the features common to both self-direction and problem-solving and adapt these to the requirements of "Westmount 1990" and the English Guideline. The result is a proposal for a problem-based independent Grade 12 course outlined in Chapter 6. / Thesis / Master of Arts (MA)

McMaster University's Department of Anatomy and Experimental Morphology has developed an extensive collection of self-directed learning modules in Anatomy which are available in an open laboratory. How medical and allied health students use this resource has never been adequately surveyed. The rates, patterns and reasons for module use among first and second year medical students were surveyed by questionnaire in late 1992. A similar questionnaire was administered to students in Block 3 of the Physiotherapy programme in early 1993. Analysis was done using a standard computer-based statistical package. Average module use among Unit 1 medical students (estimated by a weighted average) is 1.39 hours per week, with a statistically significant increase reported by Unit 4 medical students. Physiotherapy students, whose programme has a strong emphasis on musculoskeletal anatomy, had lab use rates 140% greater than Unit I medical students. Patterns of module use and student satisfaction with the modules depend not only upon the medical student's level in the programme, but also upon their previous backgrounds in biological/health science and problem-based learning experience. The rates and patterns of use were much more consistent among physiotherapy students, who were also far more satisfied with the organization and content of the modules than the medical students were. Medical students who were tutored by research scientists rather than clinicians had different rates and patterns of module use. The survey also indicates that students' use of the anatomy laboratory is not primarily driven by their tutor's suggestions; by a requirement for a detailed knowledge of anatomy for clinical skills purposes; or because module use saves time. The comparatively heavy use of the Anatomy lab and modules by physiotherapy students is clearly related to the demands of their programme. Students do believe that module use will help them contribute to their tutorial discussions and to the evaluations that occur in this setting. / Thesis / Master of Science (Teaching)

No description available.

No description available.

The focus of this project was to develop self-directed pronunciation materials for a specialized group of English as a second language (ESL) learners—missionaries at the Provo Missionary Training Center (MTC) of The Church of Jesus Christ of Latter-day Saints. A set of six Cued Pronunciation Readings (CPRs) were developed. CPRs are computer-based, self-directed pronunciation materials designed to help students perceive pausing, word stress, and sentence-final intonation in spoken English and practice these features through a sequence of oral reading tasks. The CPRs developed in this project were based on essential missionary communicative tasks and utilized high-frequency gospel vocabulary. These tasks included saying set prayers, reciting relevant scripture passages, and bearing testimonies on gospel principles. These materials, originally developed in Microsoft PowerPoint, were converted for use in an MTC application called Assessment Tools. Following development, the materials were tested with a group of ESL missionaries in the Provo MTC. Fourteen missionaries used the materials during a three-week period. They were encouraged to spend 10–15 minutes each day in the computer lab working on the tasks. At the end of three weeks, a posttest survey was administered to obtain the missionaries' feedback. The missionaries' use of the materials and their reactions are discussed. Suggestions are given for the further development of similar materials and for further implementation of these materials at the MTC.

This paper details the design and development of a self-directed character education program based on the Aims of a BYU Education. Specifically, the program was intended to meet the following objectives: (a) increase student awareness of the BYU Aims, (b) provide opportunities for students to recognize and understand principles of good character, (c) engage students in enriching application of character values, and (d) lay the foundation for lifelong learning, service, and good character. The design process followed a modified systematic approach and resulted with a pilot trial of the BYU Aims Program. The selection of design model, preliminary analyses, and formative evaluation appear to have particularly contributed to the success of the pilot. While participant feedback did suggest that involvement in the pilot helped participants meet the intended objectives, the program suffered a high participant attrition rate over the course of pilot. Participant feedback also suggested that modifications to program delivery, interface, and duration and requirements of challenge activities would be necessary to improve or maintain participant engagement in future iterations of the program.

Thesis advisor: Michael Russell / SDL is an important life-long learning skill. Current research on SDL has approached it both as a set of skills students develop and as an instructional method. The study presented here approached SDL as an instructional method and explored educators’ instructional use of SDL in relation with pedagogical beliefs, a relationship that has not been sufficiently explored in past research. This relationship was also placed in a Critical Race Theoretical Framework to explore whether the implementation of SDL differed by the racial composition of schools. A multi-method approach was taken which included surveying and interviewing middle school teachers in Massachusetts public schools. Descriptive analyses, factor analyses, correlation analyses, regression analyses, and t-tests were conducted in order to explore the relationship between teachers’ implementation of SDL and their extent of technology integration and pedagogical beliefs, as well as whether the implementation of SDL differs based on the racial composition of the schools in which teachers work. Interviews were employed to explore the results further. Teachers with more student-centered beliefs had higher levels of implementation of SDL than those with more teacher-centered beliefs, and pedagogical beliefs were also a stronger predictor of the level of implementation of SDL than were teachers’ amount of technology use or beliefs about student technology use. No significant relationship was observed between SDL and the racial composition of schools. / Thesis (BA) — Boston College, 2019. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Sociology.