Katherine C. Chen

The effect of alloying on the properties of (Nb, Ti)Cr2 C15 laves phases

Abstract The effect of composition on the ternary (NbCr 2 –TiCr 2 ) C 15 phase properties has been investigated, focusing upon the defect structure, elastic properties, and mechanical behavior. The C 15 phase field is continuous between NbCr 2 –TiCr 2 , with a maximum phase field width of at least 7 at.% solubility. The defect mechanism is governed by anti-site constitutional defects for all alloys. Mechanically, the alloys display a maximum in hardness in the center of the ternary phase field (and a minimum of toughness). The ternary phase field has features that are characteristic of solid-solution strengthening mechanisms. Finally, the elastic properties indicate that the alloys become stiffer in the middle of the ternary phase field. The best compromise of properties occurs furthest from stoichiometry in the ternary phase field at the nominal composition of Nb 19 Ti 19 Cr 62 . The relationships between the defect structure, elastic properties, and mechanical response for the C15 phases are discussed using a combination of atomic size arguments and electronic structure analyses. From these relationships, alloy design strategies for NbCr 2 -based alloys are evaluated.

Integrating project-based learning throughout the undergraduate engineering curriculum

This publication contains reprint articles for which IEEE does not hold copyright. Full text is not available on IEEE Xplore for these articles.

Work in progress: How do we teach and measure systems thinking?

Since the 1990psilas blue-ribbon commissions on engineering education have called for educators to graduate engineers who are capable of systems thinking. However, there is sparse information on how to cultivate this type of cognitive development. How do we develop and measure systems thinking? In this paper, we present the first of a series of methods that we are piloting to initiate the systems thinking process. This exercise, developed by Checkland and Scholes and called ldquorich pictures,rdquo requires the participant to express a reality in terms of images and connections between these images. We utilized the rich pictures exercise in combination with an appreciative inquiry strategy in pursuit of an initial research hypothesis regarding the impact of project-based learning on female students. We only partially answered our initial question, but the exercise unexpected yielded enthusiastic participation by the students and a rich set of data regarding unanticipated factors that influenced studentspsila learning. The value of the activity is that it initiates the process of thinking nonlinearly, an important first step in studentspsila cognitive development for systems thinking.

Nanotechnology, Biology, Ethics and Society: Overcoming the Multidisciplinary Teaching Challenges

One of the inherent challenges of teaching any emerging technology like nanotechnology, is the fact that its core competencies flux in the new disciplines’ early stages. Nanotechnology presents an additional challenge in that its underpinnings cross multiple traditional disciplinary boundaries. We have designed a course that aims to address some of these challenges through a handful of structural features: team-based learning; a “reverse of the learning pyramid” approach; team-teaching; embedded information literacy techniques; and application-centered content. Our course is organized around four applications that are in their developmental stages: gold nanoshells for cancer treatment; molecular manufacturing; tissue engineering of a vital organ; and a microfluidic glucose sensor. These applications provide natural contexts for learning biology at the cellular level, the molecular level, the organ level and the biological systems level, respectively. They also provide natural contexts to introduce ideas of scientific uncertainty in emerging fields. In this paper, we will present the design features of our sophomore-level course Nanotechnology, biology, ethics and society and some preliminary

Work in progress: How do first-year engineering students develop as self-directed learners?

Although self-direction is among the most critical skills required of todays engineering graduates, the complex processes through which individuals develop the attitudes, beliefs, and skills of lifelong, self-directed learners remains unclear. In this ongoing mixed-methods investigation, we draw on existing motivation and self-regulated learning theories to examine how undergraduate students at two institutions develop as self-directed learners during their first two years of their engineering programs. Preliminary findings indicate that both groups of first-year students make progress as self-directed learners, even after their first semester of college. However, the data indicate marked differences in specific areas of self-directed learner growth at the two institutions. Compared to those at the large public university, students at the small private college report stronger learning goal orientations, help-seeking behaviors, and metacognitive strategy use. We discuss how the learning opportunities and environments may contribute to these differences in learner development.

Work in progress - a design guide to retain female (and male) students in engineering

Despite a rich body of research on factors contributing to attrition of women during the college, women continue to be underrepresented in the graduating classes of most traditional engineering disciplines. We present our Four-Domain Development Diagram (4DDD) in an attempt to enable a systems approach to managing all the factors that contribute to retention. This diagram makes explicit the connections between the learnerspsila response factors in the learning environment, including motivation, interest, and ultimately retention. Although we are only three years into our use of the diagramspsila relationships, we have seen a lower overall net attrition rate (male and female) from freshman year from ~50% to ~20%, seeing a net influx of female students, from numbers as low as 2 of 44 in the entering freshmen cohort to 6 out of 40 (now sophomores) in that same cohort. In this paper, we present the diagram, briefly introduce the theoretical underpinnings with preliminary quantitative and qualitative data.

The role of collaborative inquiry in transforming faculty perspectives on use of reflection in engineering education

During the 2014-2015 academic year, engineering faculty members and students at California Polytechnic State University (Cal Poly) met monthly in a collaborative inquiry dialogue group to discuss the role of reflection in transforming engineering education. This project is part of the larger Consortium to Promote Reflection in Engineering Education (CPREE) headed by the University of Washington. In this paper we describe the activities of the Cal Poly group involved with CPREE and how these activities have transformed the thinking and actions of participants. Collaborative inquiry dialogue involves self-organizing individuals into a small group to address a compelling question through repeated cycles of experimentation and reflection on the results of that experimentation. In this context, the faculty members involved (including the authors of this paper) have been meeting to discuss how use of reflection in the classroom and/or in a collaborative inquiry dialogue amongst colleagues might lead to transformation in engineering education practice and outcomes. The dialogue group serves as a safe container that allows for the possibility of transformational insights by participants - insights that change their view of themselves, the world, and their relationship to it. Using a qualitative self-report methodology in the tradition of an action research paradigm, we (the authors) reflected on what we believed we had gained from the collaborative inquiry dialogues. Broadly we have noticed that participation in the collaborative inquiry dialogue has led us to reconsider what reflection is and what it could be, to develop a greater appreciation for the role of reflective practices in engineering education, and to better recognize when reflection is occurring (and when it might not be) such that reflective behaviors can be encouraged and practiced. We also began to challenge assumptions we had made about our teaching practices and have noted that the collaborative inquiry provides an environment in which development of new thinking is possible.

Work in progress: Outreach assessment: Measuring engagement: An integrated approach for learning

The Learn By Doing Lab (LBDL) at Cal Poly, San Luis Obispo is an on-campus laboratory where 5th through 8th grade students are taught by undergraduates who may be planning a careers in teaching. The two populations -elementary students and undergraduates - are equally important in the process. Since 2008, the lab has seen over 4000 elementary and junior high students and over 100 undergrads have participated. In most outreach assessment the number of individuals participating is an important metric, but this last Spring we experimented with a more in depth measure of effectiveness. As in any learning experience engagement in the process is an essential ingredient. Although there are several methods of measuring engagement, we chose to observe the activity of the participants as a proxy for engagement. Two industrial engineering (IE) undergraduates who themselves have been exposed to the topics of work sampling and observation studies had an opportunity to improve professional skills through this application. This involvement of undergraduates is consistent with the LBDL and Cal Polys motto of “learn by doing.” These two students, who are also coauthors, spent multiple hours coding and randomly sampling the of the elementary and junior high students as well as the undergraduate teachers activities. Not only did the IE students discover important insights for the LDBL they also learned how to apply work sampling in a research setting. This paper discusses the integrated learning environment and the next steps involved in these undertakings.

Work in Progress: Crossing the Engineering Border into Art and Society with a Materials Selection for the Life Cycle course

A new course in materials engineering has been developed to incorporate industrial design and sustain ability principles. Many current engineering tasks require the ability to comprehend and consider the complicated interplay of technology with the environment and society. Thus the changing skill set required of future engineers is being reflected in the changes with our courses. We are stepping beyond the traditional boundaries of engineering courses to present a more holistic approach to problem solving. The use of materials and processing techniques is applied to product design, and thus involves consideration of the end user and the end of product life. Green engineering and cradle to cradle design principles are also introduced in the course. Outcomes for this class include students being able to employ systems thinking, to formulate creative design solutions, and to select the appropriate materials and processing for minimal environmental impact

Entering the Metals Zone

Publisher Summary This chapter focuses on the metal zone. Metals are found everywhere in the Materials World, and a world without any metals are unimaginable. Some objects, such as forks, could be made of plastics rather than sterling silver, however, some applications like skyscrapers or jet planes would never exist without metals. The chapter explores metals across several length scales, from the atomic level up to the bulk, and establishes how the properties are a direct outcome of the structure. Different schemes or frameworks of how to think about some of the concepts are presented. Certain phrases that are descriptive of “concepts” are used to help understand the “effects” or behavior of metals. The lists of the effects, concepts, and constructs are presented in this chapter. Metals are primarily made up of metallic elements. A quick scan of the Periodic Table reveals that most elements are metals. The metallic elements are electropositive and are quite willing to give up or share their valence electrons.