THE DEVELOPMENT OF A MECHATRONICS AND MATERIAL HANDLING COURSE: LABORATORY EXPERIMENTS AND PROJECTS

Mechatronic systems integrate technologies from a variety of engineering disciplines to create solutions to challenging industrial problems. The material handling industry utilizes mechatronics to move, track, and manipulate items in factories and distribution centers. Material handling systems, because of their use of programmable logic controllers (PLC), PLC networks, industrial robotics, and other mechatronic elements, are a natural choice for a college instructional environment. This thesis offers insight and guidance for mechatronic activities introduced in a laboratory setting. A series of eight laboratory experiments have been created to introduce PLCs, robotics, electric circuits, and data acquisition fundamentals. In-depth case studies synthesize the technologies and interpersonal skills together to create a flexible material handling system. Student response to the course and laboratory material was exceptional. A pre and post course questionnaire was administered which covered topics such as teamwork, human factors, business methods, and various engineering related questions. Quantitative scores resulting from these questionnaires showed a marked improvement by students, especially in regards to technical/engineering questions. The responses from students generally indicated an excitement about course material and a thorough understanding of the various syllabus topics. In this thesis, the multi-disciplinary mechatronics (and material handling systems) laboratory will be presented. An in-depth examination of each laboratory will be offered as well as the discussion of two material handling case studies. The Appendixes contain the PLC and robot code for a order fulfillment case study

Measurement of residual stresses in a dissimilar metal welded pipe

Dissimilar metal welds (DMW) are used in light water reactor power plants to join ferritic and austenitic steel piping components. High residual stresses remaining in this type of welded joint can significantly increase its susceptibility to stress corrosion cracking (SCC) under water reactor chemistry conditions. This degradation mechanism has compromised the integrity of many nuclear power plants throughout the world over the past 10 years. The Open University (OU) is undertaking a programme of research aimed at improving the reliability of residual stress measurements in DMWs using neutron diffraction. AREVA, the French nuclear power plant constructor, has developed an improved narrow gap DMW weld using a nickel-based corrosion resistant filler (alloy-52) to eliminate the risk of SCC in next generation nuclear plant. Through-wall neutron measurements have been carried out on a full-size DMW mock-up (352 mm OD, 40 mm thick) using the ENGIN-X instrument at the ISIS Facility in the UK. The results have shown that the largest tensile stress components in the welded component lie in the hoop direction, and have values of around 250 MPa and 225 MPa in the austenitic and alloy-52 materials respectively. These measured stresses were in reasonable agreement with those obtained from deep-hole drilling and numerical simulations. A notable finding in the experimental work was a wide scatter in the measured unstressed lattice parameters within a range equivalent to micro-strains of ≈ 430, 400 and 600 for austenitic stainless steel, ferritic steel and alloy-52 respectively. This scatter was reduced by two orders of magnitude through making additional measurements whilst slowly rotating the stress-free reference cubes. The OU is undertaking systematic studies to identify the origins of the observed measurement scatter in order to improve the reliability of measurements

Storyteller, Story-Teacher: A Portrait of Three Teachers? Use of Story in Elementary Classes

The purpose of this qualitative study was to investigate the use of storytelling as a teaching strategy in the classrooms of three experienced elementary school teachers. Storytelling is defined in this study as the use of a narrative, spoken or written, in prose or in verse, true or fictitious, related so as to inform, entertain, or instruct the listener or reader. This research answers questions concerning; (a) what constitutes storytelling in these teachers’ classrooms, (b) teachers’ purposes for using storytelling, and (c) factors that have encouraged these teachers to employ storytelling in their teaching practices. Framed within constructivist theory, the study provides insight into how these three respondents teach content through storytelling and bridge information from teller to listener. Data collection included classroom observations, interviews of teacher-participants, and the collection of teacher-generated artifacts such as lesson plans and teacher notes. Portraiture is used as a method for writing up the data in order to record the perspectives and experiences of the participants in this study by documenting their voices, visions, and wisdom in a detailed exploration into the feelings about and use of storytelling in their teaching practices. The instructional strategies reported through this qualitative inquiry support a socio-cognitive interactive model of literacy and demonstrate its importance in learning content in an elementary school environment. The data were analyzed continually through a search for emerging patterns and through constant comparison analysis. The researcher found that the teachers used stories and illustrations in an impromptu manner and that storytelling served both cognitive and affective purposes. Cognitively, storytelling was employed to form connections to students’ prior knowledge and new knowledge being introduced. Storytelling was used as a mnemonic device to help students transfer storied information to new situations. Affectively, storytelling served to engage students in an enlightening and entertaining manner. Students responded to the use of stories through actively participating in classroom discussions and sharing stories of their own. Storytelling assists these teachers in their critical roles as negotiators and facilitators of meaning construction in the text and social context of the classroom

Orbit-Spin Coupling, the Solar Dynamo, and the Planetary Theory of Sunspots

Orbit spin coupling is proposed as an alternative to planetary tidal models for the excitation of solar variability as a function of time. Momentum sourced from the orbital angular momenta of solar system bodies is deposited within the circulating fluid envelopes of the Sun and planets in this hypothesis. A reversing torque acts about an axis lying within the Sun's equatorial plane. The torque gives rise to tangential differential accelerations of solar materials as a function of longitude, latitude, depth, and time. The accelerations pulse in amplitude, and change sign, on timescales corresponding to the periods, beats, and harmonics of inner and outer planet orbital motions. In contrast to planetary tidal models, no special amplification mechanism may be required, as estimated peak accelerations are about 2 orders of magnitude larger than the largest tidal accelerations. Organized mass motions driven by the torque may be incorporated in dynamo simulations through the flow velocity term of the MHD induction equation. The spatiotemporal variability of flow velocities may then influence the variability with time of solar magnetic activity. We provide torque values at 1 day timesteps for the years 1660 to 2220. We discuss the time variability of the torque in juxtaposition with SIDC monthly sunspot numbers from 1750 to present. We investigate Hale cycle synchronization, and the variability with time of the total solar irradiance, with reference to outer and inner planet contributions respectively. We propose a 3 component model for understanding and simulating the solar magnetic cycle, which includes processes internal to the Sun, external forcing, due to orbit spin coupling, and a time-delay, or system memory, component. This model supplies a physical explanation for the observed variability with time of Schwabe cycle periods and Hale cycle periods from 1712 to present.Comment: 95 pages, 8 Figure