Relationships Between Student Self-Assessment Ability and Performance

Knowledge surveys (KS) are a self-assessment tool where the questions correspond one-for-one with learning objectives in a course. In response to the KS questions, students select a confidence rating that describes their self-assessed ability to demonstrate understanding or perform a skill. Pre-KS at the beginning of a course or unit of instruction serve as an outline of future learning objectives for students and alert faculty to pre-existing student capabilities. Students can access the KS questions continuously during the unit of instruction as a formative learning guide. Post-KS immediately prior to a summative exam enable comparison of student self-assessments of learning with faculty assessments of student performance. Fundamental Hydraulics is a junior level fluid mechanics course required for civil engineering majors at a small university in the Western United States. KS were employed in eight sections of Fundamental Hydraulics from Spring 2019 to Spring 2021 with a total student population of 118. Prior research on KS in this course has shown that student self-assessments via KS are well-aligned with their exam scores. Given the data set in this course, we further explored relationships between student performance and their self-assessment abilities. Results show that the correlation between student KS scores and their grades on each of the three unit exams in the course improves with each successive cycle of performance and feedback. We also examined the self-assessment ability of the student cohort by upper and lower halves of cumulative GPA, measured as of the semester prior to taking Fundamental Hydraulics. These data show that students in the upper half by GPA maintained consistent self-assessment accuracy through the three exams while students in the lower half by GPA improved their selfassessment accuracy by the third exam. Finally, we examined whether student performance improved in conjunction with the improvement in self-assessment accuracy. Although results are mixed as to whether student performance improved in a single semester, the self-assessment skills demonstrated by the entire student cohort, and particularly the improvement shown by the lower half of students by GPA, offers further encouragement that KS are a useful tool to support development of self-assessment skills and student learning

Spacecraft Shielding

The present invention relates to spacecraft shielding, articles comprising such shielding as well as processes of making and using spacecraft shielding and articles comprising such shielding. Such shields are made by a 3D process that provides significant shield geometry and composition flexibility and yields shields that have significantly improved shield performance. Such shields may be efficiently be manufactured in space

Collaborative Senior Design Capstone at Two Geographically Separated Universities

As remote engineering collaboration increases in popularity due to the proliferation of networking tools and the expansion of telework opportunities resulting from the shutdowns of COVID-19, the need to study their efficacy grows. This work examines a collaboration conducted between two geographically separated universities to complete a mechanical engineering design experience. While such an experience may be rare within academic design courses, it undoubtedly reflects the reality of engineering teams in industry and government that are comprised of geographically separated teams. Three teams of students, that each included students from both schools, worked for an academic year to complete three unique capstone projects, with three different advisors. The students were provided various computer-based collaboration tools and encouraged to use them throughout. This work examines their experiences to investigate successes and potential improvements during each design phase, to include consideration of how the provided tools enabled or hindered remote collaboration. Additionally, this work surveyed project sponsors to determine how the remote collaboration teams' performance compared to previous years of collocated teams. Survey data were collected following three significant milestones during the design efforts: preliminary design review (PDR), critical design review (CDR), and the final briefing. Results show that the geographically separated teams performed equivalently to collocated teams, though they encountered challenges during the prototyping and testing design activities

Precipitate Structure, Microstructure Evolution Modeling and Characterization in an Aluminum Alloy 7050 Friction Stir Weld

Novel use of differential scanning calorimetry (DSC), with 1.7 mm specimen spacing intervals across a friction stir weld, coupled with microhardness, electrical conductivity, transmission electron microscopy (TEM), and novel three-dimensional thermal modeling of temperature profiles were used to characterize precipitate structure as a function of position across a friction stir welded and post-weld stabilized aluminum alloy 7050. The results show excellent agreement with predictions of existing FSW microstructural evolution models for 7XXX aluminum alloys. The DSC scans and thermal modeling accurately predicted the locations and peak temperatures at which transitions from 1) slow precipitate dissolution to 2) rapid dissolution, coarsening, and transformation of η′ to η precipitates to 3) increasing η dissolution and matrix supersaturation occur along the weld. These results are correlated to significant changes in the microhardness and electrical conductivity profiles. Following a 12-year period after the initial post-weld stabilization treatment, the closely spaced DSC scans were able to show that the initial stabilization treatment, (a standard T6 heat treatment), had not fully stabilized the weld near the heat affected zone (HAZ) hardness minimum. A 2-step stabilization method is proposed to fully stabilize the material in this region of the weld

Design and Evaluation of Additively Manufactured Polyetherimide Orbital Debris Shielding for Spacecraft

The increasingly congested orbital environment around Earth threatens the safety of space assets. Micrometeoroids and orbital debris (MMOD) less than 1 cm but traveling at hypervelocities pose a serious but defensible hazard. Traditional shields are installed during spacecraft assembly and must survive launch loads, constraining their size, shape, and ultimately, effectiveness. Recent advances in on-orbit additive manufacturing have created new opportunities for shield design and deployment. This work describes the modeling and testing of additively manufactured polyetherimide shields. The finite element code CTH was used to model hypervelocity impacts (HVIs) of such shields, and though imperfect, the models were useful for shield design. Several shield designs were additively manufactured and underwent HVI testing with a two-stage light gas gun in the regime of 4 mm diameter aluminum projectile impacts at 5 - 6.5 km/s. All successfully survived the HVIs, indicating their potential effectiveness as MMOD spacecraft shielding

Engineering Problem Solving: Implementing a New Foundational Engineering Course

This study investigates how a new first semester of a new first-year engineering course affected student engineering skills, feelings about engineering, and hesitations to declare an engineering major. Pre-and post-course surveys and interviews were conducted with eighteen students who took Engineering Problem Solving in the fall semester 2023. The course was designed to require significant teamwork among students. The course introduced students to a variety of engineering disciplines through hands-on activities. Additionally, several assignments required the students to view short video interviews with practicing exemplars who came from underrepresented groups in engineering. Results indicate students increased their skills in several engineering tasks, their confidence and sense of belonging in engineering increased slightly, and students had fewer hesitations to declare an engineering major at the conclusion of the course than prior to the course

Here’s to Chicanos in the Middle Class!

This chapter explains why the topic of Mexican American culture became especially urgent during the 1960s and 1970s, and shows why this emphasis on culture came under question during the 1980s. Arellano describes how the Chicano literary intervention was crucial for exposing reductive caricatures by providing more nuanced characterizations of Mexican Americans. This focus on nuanced characterization, however, ultimately risked obfuscating the damaging effects of class struggle. Referencing the competing visions of Tomás Rivera and Richard Rodriguez, concerning the value of culture, Arellano analyzes literary case studies by José Antonio Villarreal and Arturo Islas, showing how their emphasis on a shared ethnic identity occluded class inequality. Arellano concludes by analyzing Rolando Hinojosa’s novel We Happy Few, which reconsiders the legacy of Chicano activism, demonstrating how Hinojosa disarticulates the novel’s meaning from cultural unity and reconnects it to the needs of workers. The novel thus highlights a view of literature that takes Mexican American humanity as a given and directs readers’ critical attention toward the problems that arise from a society organized by class

A Formal Consideration of User Tactics During Product Evaluation in Early-Stage Product Development

Frequent and effective design evaluation is foundational to the success of any product development effort. Products used, installed or otherwise handled by humans would benefit from an evaluation of the product while formally considering both the physical embodiment of the technology, termed technology, and the steps a user should take to use that technology, termed tactics. Formal and simultaneous evaluations of both technology and tactics are not widespread in the product design literature. Although informal evaluation methods have advantages, formal methods are also known to be effective. In this paper we propose a formal method for evaluating tactics and technology simultaneously. Unlike the published literature, this evaluation involves explicitly defined tactics in the form of a written description of the actor, environment and series of steps. It also involves the use of stage appropriate, explicitly defined tactics-dependent criteria, which include criteria from a broad range of impact categories

Exploring Solutions for Container Image Security

Guided by NIST’s Application Container Security Guide, we explore workflows to address container image vulnerabilities that have known fixes. The approach stems from the idea that a DevOps team should always build container images that meet a specified security standard. We outline a blueprint that leverages a vulnerability scanner to establish a baseline of security issues and reduces that list via an automated patching process. We target popular images in common use: scanning each image identifies potential vulnerabilities and misconfigurations, and we compare the results of our automated pipeline against both the original image and a manually patched one. Through our work, we identified technical barriers to patching fixable vulnerabilities in off-the-shelf (OTS) images, a lack of accountability for badges used by popular container registries, and that responsibility for container security falls heavily on the shoulders of users