More Like this

1. Student agency in chemical engineering laboratory courses across two institutions

   Svihla, V. ; Wilson-Fetrow, M. ; Chi, E. ; Brown, J. ; Wettstein, S. ; Hubka, C. ; Lopez, R.D. ( July 2023 , ASEE Annual Conference proceedings)

   Laboratory experimentation is a key component of the development of professional engineers. However, experiments conducted in chemical engineering laboratory classes are commonly more prescriptive than the problems faced by practicing engineers, who have agency to make consequential decisions across the experiment and communication of results. Thus, understanding how experiments in laboratory courses vary in offering students opportunities to make such decisions, and how students navigate higher agency learning experiences is important for preparing graduates ready to direct these practices. In this study, we sought to answer the following research questions: How do students perceive their agency in course-based undergraduate research experiences? What factors are measured by the Consequential Agency in Laboratory Experiments survey? To better understand student perceptions of their agency in relation to laboratory experiments, we first conducted a case study of a course-based research experience (CURE) in a senior-level chemical engineering laboratory course. We then surveyed six upper-division laboratory courses across two universities using an initial version of the Consequential Agency in Laboratory Experiments survey. We used exploratory factor analysis to investigate the validity of the data from the survey for measuring relevant constructs of authenticity, agency in specific domains, responsibility, and opportunity to make decisions. We found that with instructional support, students in the CURE recognized that failure could itself provide opportunities for learning. They valued having the agency to make consequential decisions, even when they also found the experience challenging. We also found strong support for items measuring agency as responsibility, authenticity, agency in the communication domain, agency in the experimental design domain, and opportunity to make decisions. These findings give us insight into the value of higher agency laboratory experiments, and they provide a foundation for developing a more precise survey capable of measuring agency across various laboratory experiment practices. Such a survey will enable future studies that investigate the impacts of increasing agency in just one domain versus in several. In turn, this can aid faculty in developing higher agency learning experiences that are more feasible to implement, compared to CUREs. 

   more » « less
2. Work in Progress: Interactive Introductory Online Modules on Wireless Communications and Radio-frequency Spectrum Sharing

   Dietrich, C. B. ; Polys, N. F. ; Reid, K. ; García Sheridan, J. A. ; Emenonye, D. ; Gomez, X. ; Tolley, J. ; Makin, C. ; Gaeddert, J. ( July 2021 , ASEE Annual Conference proceedings)

   1. Description of the objectives and motivation for the contribution to ECE education The demand for wireless data transmission capacity is increasing rapidly and this growth is expected to continue due to ongoing prevalence of cellular phones and new and emerging bandwidth-intensive applications that encompass high-definition video, unmanned aerial systems (UAS), intelligent transportation systems (ITS) including autonomous vehicles, and others. Meanwhile, vital military and public safety applications also depend on access to the radio frequency spectrum. To meet these demands, the US federal government is beginning to move from the proven but inefficient model of exclusive frequency assignments to a more-efficient, shared-spectrum approach in some bands of the radio frequency spectrum. A STEM workforce that understands the radio frequency spectrum and applications that use the spectrum is needed to further increase spectrum efficiency and cost-effectiveness of wireless systems over the next several decades to meet anticipated and unanticipated increases in wireless data capacity. 2. Relevant background including literature search examples if appropriate CISCO Systems’ annual survey indicates continued strong growth in demand for wireless data capacity. Meanwhile, undergraduate electrical and computer engineering courses in communication systems, electromagnetics, and networks tend to emphasize mathematical and theoretical fundamentals and higher-layer protocols, with less focus on fundamental concepts that are more specific to radio frequency wireless systems, including the physical and media access control layers of wireless communication systems and networks. An efficient way is needed to introduce basic RF system and spectrum concepts to undergraduate engineering students in courses such as those mentioned above who are unable to, or had not planned to take a full course in radio frequency / microwave engineering or wireless systems and networks. We have developed a series of interactive online modules that introduce concepts fundamental to wireless communications, the radio frequency spectrum, and spectrum sharing, and seek to present these concepts in context. The modules include interactive, JavaScript-based simulation exercises intended to reinforce the concepts that are presented in the modules through narrated slide presentations, text, and external links. Additional modules in development will introduce advanced undergraduate and graduate students and STEM professionals to configuration and programming of adaptive frequency-agile radios and spectrum management systems that can operate efficiently in congested radio frequency environments. Simulation exercises developed for the advanced modules allow both manual and automatic control of simulated radio links in timed, game-like simulations, and some exercises will enable students to select from among multiple pre-coded controller strategies and optionally edit the code before running the timed simulation. Additionally, we have developed infrastructure for running remote laboratory experiments that can also be embedded within the online modules, including a web-based user interface, an experiment management framework, and software defined radio (SDR) application software that runs in a wireless testbed initially developed for research. Although these experiments rely on limited hardware resources and introduce additional logistical considerations, they provide additional realism that may further challenge and motivate students. 3. Description of any assessment methods used to evaluate the effectiveness of the contribution, Each set of modules is preceded and followed by a survey. Each individual module is preceded by a quiz and followed by another quiz, with pre- and post-quiz questions drawn from the same pool. The pre-surveys allow students to opt in or out of having their survey and quiz results used anonymously in research. 4. Statement of results. The initial modules have been and are being used by three groups of students: (1) students in an undergraduate Introduction to Communication Systems course; (2) an interdisciplinary group of engineering students, including computer science students, who are participating in related undergraduate research project; and (3) students in a graduate-level communications course that includes both electrical and computer engineers. Analysis of results from the first group of students showed statistically significant increases from pre-quiz to post-quiz for each of four modules on fundamental wireless communication concepts. Results for the other students have not yet been analyzed, but also appear to show substantial pre-quiz to post-quiz increases in mean scores. 

   more » « less
3. Chemical imaging of latent fingerprints, paint chips, and fibers using µ-FTIR: An experiment for forensic chemistry and instrumental analysis courses

   Chamblee, Reba ; Wontor, Kendall ; Cizdziel, James. ( June 2023 , The journal of forensic science education)

   Emerging technology combining spectroscopy with microscopy is advancing the analysis of trace evidence with the potential to revolutionize forensic microscopy and excite a new generation of forensic microscopists. In this laboratory experiment, developed for undergraduate forensic chemistry and instrumental analysis courses, students use Fourier transform infrared (micro)spectroscopy (µ-FTIR) to analyze mock forensic samples commonly encountered at crime scenes, including latent fingerprints (laced with ibuprofen to mimic an illicit drug), vehicle paint chips, and acrylic fibers. Unlike light microscopy, µ-FTIR provides information on the spatial distribution and chemical nature of the sample. Learning objectives were to reinforce key concepts covered in the classroom, including collection and preparation of trace evidence, forensic microscopy, and vibrational spectroscopy, as well as to provide students hands-on experience using a state-of-the-art instrument. Students prepared the fingerprint and fiber samples for analysis, whereas the paint chip was previously cross-sectioned to save time. The students collected and processed their own data, including generating chemical distribution maps. Student responses to the exercise were positive and reports written by the students demonstrated an increased awareness of the capabilities of FTIR microscopy and chemical imaging. Overall, the exercise helped remove the “black box” mentality, where students analyze samples without understanding the fundamentals of the technique, which is so important to recognize poor data quality and troubleshoot instruments. This report describes the laboratory exercise and student experience, and includes data and chemical images collected by students, and aspects of the experiment that could be modified to improve learning outcomes. 

   more » « less
4. The effect of local lithium surface chemistry and topography on solid electrolyte interphase composition and dendrite nucleation

   https://doi.org/10.1039/C9TA03371H  

   Meyerson, Melissa L. ; Sheavly, Jonathan K. ; Dolocan, Andrei ; Griffin, Monroe P. ; Pandit, Anish H. ; Rodriguez, Rodrigo ; Stephens, Ryan M. ; Vanden Bout, David A. ; Heller, Adam ; Mullins, C. Buddie ( June 2019 , Journal of Materials Chemistry A)

   With more than 10 times the capacity of the graphite used in current commercial batteries, lithium metal is ideal for a high-capacity battery anode; however, lithium metal electrodes suffer from safety and efficiency problems that prevent their wide industrial adoption. Their intrinsic high reactivity towards most liquid organic electrolytes leads to lithium loss and dendrite growth, which result in poor efficiency and short circuiting. However, the multitude of factors that contribute to dendrite formation make determining a nucleation mechanism extremely difficult. Here, we study the intricate science of dendrite nucleation on metallic lithium by using an array of analytical techniques that provide simultaneous ultra-high spatial sensitivity and chemical selectivity. Our results reveal a 3D picture of the chemical make-up of the native Li surface and the resulting solid electrolyte interphase (SEI) with better than 200 nm resolution. We find that, contrary to the general understanding, the initial surface chemistry, not the topography, is the dominant factor leading to dendrite nucleation. Specifically, inhomogeneously distributed organic material in the native surface leads to inhomogeneously dispersed LiF-rich SEI regions where dendrite nucleation is favored. This has significant implications for battery research as it elucidates a mechanism for inhomogeneous SEI formation, something that is accepted, but not well understood, and highlights the importance of Li surface preparation for experimental studies, which is implicit in battery research, but not directly addressed in the literature. By homogenizing the initial lithium surface composition, and thus the SEI composition, we increase the number of dendrite nucleation sites and thereby decrease the dendrite size, which significantly increases the electrode lifetime. 

   more » « less
5. Don’t Drink and Fly: Alcohol Resistance Behavior in Drosophila Informs us about Genes that Contribute to Alcoholism

   Echeverria, Jennifer S. ; Key, S. Catherine ( April 2022 , Advances in biology laboratory education)

   Thuecks, Suzanne ; Ettinger, Audrey J. (Ed.)

   Many undergraduate students understand that model organisms are important for understanding how biology works, but may not make the connection that animal models such as Drosophila melanogaster can be used to understand such human conditions as Alcohol Use Disorder (AUD) and Fetal Alcohol Syndrome (FAS). To address this knowledge gap, we introduced an inquiry-based laboratory module in which students perform hands-on Ethanol Behavior Mobility Assays (EMBAs) using flies with either different Alcohol Dehydrogenase (ADH) alleles or different developmental exposure to ethanol. The lab module contains a bioinformatic component for students to explore the evolutionary conservation of the ADH gene between flies and humans. The implementation of this exercise in a sophomore/junior-level Genetics course led to a high level of student satisfaction and a more integrated view of the role of model organisms in studying AUD and FAS. Funding acknowledgements: ABLE Roberta Williams Laboratory Teaching Initiative Grant and NSF HBCU-UP TIP Grant # 1912188. 

   more » « less