Search

Spreadsheets are a core computational tool for practicing engineers and engineering students. While Microsoft Excel, Google Sheets, and other spreadsheet tools have some differences, numerous formulas, functions, and other tasks are common across versions and platforms. Building upon learning science frameworks showing that interactive activities are advantageous, an interactive textbook from zyBooks was created to provide students the opportunity to acquire spreadsheet skills by doing. Interactive components include stepping through animations, completing multiple choice and matching questions, and evaluating spreadsheet formulas and functions using 100+ auto-graded, randomized questions. While the interactive reading participation was discussed in previous work, the focus here is on auto-graded questions, sometimes called online homework. Fraction correct regardless of attempts, number of attempts before correct, and number of attempts after correct provided metrics to examine deliberate practice across three cohorts encompassing over 250 students. Sections grouped as General spreadsheet skills or Functions generally showed greater median correct, ranging from 76 to 90%, than sections categorized as Advanced spreadsheet skills, which led to median correct of 68 to 81%. Median correct also varied between different question types and decreased with question order, which aligns with questions being scaffolded. Finally, a hypothesis was tested: Adding a Copy sheet feature to the auto-graded questions would encourage deliberate practice and improve fraction correct between cohorts. Over 80% of students used the new Copy sheet button, and a statistically significant increase with large effect size in fraction correct between cohorts was found, which supports the hypothesis.

In response to the COVID-19 pandemic, chemical engineering departments from around the world shifted their course offerings from in-person to online almost instantaneously. The AIChE Education Division immediately responded to this educational shift by developing five Virtual Communities of Practice (VCPs) that allowed faculty to share experiences and best practices as well as provide a network for emotional support. Community creation, methods and materials shared, and surveys related to the impact of this initiative will be discussed.

The utility of Just-In-Time-Teaching (JITT) is compared across course topics and groups of students not receiving JITT exercises in class. JITT feedback incorporated various active learning exercises based on students' performance on online homework problems from Sapling Learning. With over 200 students in two sections participating in the sophomore level introductory thermodynamics course, student performance was evaluated on in-class quiz and exam problems. Student performance covering a specific course topic subsequently reinforced by a JITT exercise was found to be measurably higher (>9%) than a control group who did not receive the JITT review. Overall, comparing student achievement across five topics covered by JITT compared with five different course topics not covered by JITT did show small positive outcomes. The improvements after using JITT exercises included a higher median and 3rd quartile scores, so JITT may be beneficial to mid-performing students. Overall, student feedback on the JITT reviews showed that over 85% of the students thought the JITT exercises were helpful for engagement and a good use of class time.

Xanthan gum, a naturally‐occurring, high‐molecular‐weight, anionic polyelectrolyte, exhibits significant drag‐reducing properties at low concentrations in water, suggesting promising applications in geothermal networks. The flow behavior of xanthan solutions are explored, specifically at concentrations in the semi‐dilute (1000 ppm by mass) and entangled (4000 ppm) regimes as well as in both water and various salt solutions across a temperature range of 5–85°C. The viscosity and viscoelastic properties of xanthan solutions examine relationships between polyelectrolyte concentration, temperature, and salt concentration. Viscosity decreases by two orders of magnitude in 4000 ppm xanthan solutions in deionized water and with 50 mM NaCl (in the high salt limit) as the temperature increases from 5 to 85°C. Next, the addition of salts affects viscosity differently in the two concentration regimes. Specifically, at 25°C, the zero‐shear rate viscosity upon salt addition decreases by 63% for 1000 ppm solutions (from 0.54 to 0.2 Pa s) but increases by 280% for 4000 ppm solutions (from 28 to 107 Pa s). At 1000 ppm, salt ions cause chain collapse, reducing viscosity; At 4000 ppm, entanglements led to structural changes, resulting in higher viscosity. Furthermore, three salts commonly found in geothermal waters, namely NaCl, Na2CO3, and NaHCO3, exhibited similar changes in viscosity and shear thinning behavior in the entangled regime across temperatures from 5 to 85°C. [ABSTRACT FROM AUTHOR]

The impact of solving novel video-inspired homework problems on learning attitudes toward chemical engineering was examined at beginning and end of an undergraduate material and energy balances course using a modified Colorado Learning Attitudes about Science Survey instrument. Mean overall attitude of participants improved by a normalized gain factor of 14% with a small effect size (Hedge's g = 0.28). Improvement was most prominent in attitudes towards personal interest and relation to the real world.

Student success and attempts on hundreds of online homework problems housed in a fully interactive online textbook, Material and Energy Balances zyBook, were studied over three cohorts of students (n=284). Auto-graded homework questions with randomized numbers and content can explore proficiency in the course material. Students are allowed to attempt any question as many times as needed, and a median success of 94% was found. Also, students completed thousands of attempts after correctly answering without the incentive to improve grades.

Anion exchange membranes (AEMs) are a promising class of materials for applications that require selective ion transport, such as fuel cells, water purification, and electrolysis devices. Studies of structure–morphology–property relationships of ion-exchange membranes revealed that block copolymers exhibit improved ion conductivity and mechanical properties due to their microphase-separated morphologies with well-defined ionic domains. While most studies focused on symmetric diblock or triblock copolymers, here, the first example of a midblock quaternized pentablock AEM is presented. A symmetric ABCBA pentablock copolymer was functionalized to obtain a midblock brominated polymer. Solution cast films were then quaternized to obtain AEMs with resulting ion exchange capacities (IEC) ranging from 0.4 to 0.9 mmol/g. Despite the relatively low IEC, the polymers were highly conductive (up to 60 mS/cm Br− at 90 °C and 95%RH) with low water absorption (

YouTube Fridays devotes a small fraction of class time to student-selected videos related to the course topic, e.g., thermodynamics. The students then write and solve a homework-like problem based on the events in the video. Three recent pilots involving over 300 students have developed a database of videos and questions that reinforce important class concepts like energy balances and phase behavior. A set of example problems and videos are presented from a sophomore level engineering thermodynamics course and a sophomore level material and energy balances course. Student evaluations found a vast majority (79%) of the students felt better at relating real world phenomena to thermodynamics from participating in YouTube Fridays. Overall, YouTube Fridays is a student led activity that provides practice of problem solving on open-ended, course related questions.

Identifying the different concentration regimes in polyelectrolytes is helpful for tuning the viscosity in personal care products, as well as in creating other polymer materials, including anion exchange membranes. Viscosity scaling distinguishes various concentration regimes in polyelectrolyte solutions, which change in the presence of salt. Here, the first objective was to measure the viscosity scaling for two cationic polyelectrolytes in water, acid (0.1 M HCl), and salt (0.1 M NaCl) solutions. Two polymers containing the same cationic group were compared, namely, a copolymer poly(acrylamide-co-diallyldimethylammonium chloride) (PAAcDMAC) and a homopolymer poly(diallyldimethylammonium chloride) (PDADMAC). Polyelectrolyte concentrations from 0.25 to 18 wt% spanned from dilute to entangled concentration regimes depending on the polyelectrolyte. Acid and salt had comparable effects on the polyelectrolytes' viscosity. Specifically, the viscosity of the PAAcDMAC in 0.1 M NaCl in the dilute region decreased by 57% compared to DI water. Since salt ions screen the electrostatic interactions, polymer chains assume a more compact conformation. Little difference in zero-shear viscosity existed in the semi-dilute regimes for DI water and 0.1 M NaCl solution of PAAcDMAC. However, zero-shear rate viscosity increased by up to 18% with salt addition in the entangled regime. Since the rheology of entangled polyelectrolytes has not been extensively studied, small and large amplitude oscillatory experiments were completed to elucidate differences in viscoelasticity upon the addition of salt. Subtle differences in viscoelastic properties of 18 wt% PAAcDMAC solution were found upon salt addition in entangled regime. For example, large amplitude oscillatory experiments measured changes in maximum and minimum storage moduli upon NaCl addition. Thus, a disproportional change to the elastic behavior was captured upon salt addition. [ABSTRACT FROM AUTHOR]

Inspired by YouTube videos, students created homework problems as part of a class project. The project has been successful at different parts of the semester and demonstrated learning of course concepts. These new problems were implemented both in class and as part of homework assignments without significant changes. Examples from a material and energy balances course as well as a transport phenomena course demonstrated the breath of topic, rigor, and type of problem (concepts or calculations). Students using the YouTube homework problems for one section of material achieved improved grades on a single exam problem in a heat transfer course when compared with students completing textbook homework problems covering the same material. Surveys of participating students in 2012 showed that 88% of the students feel they learn from the student-written YouTube problems. Overall, a new method to develop homework problems can help faculty avoid using textbook problems repeatedly, whose solutions manuals are readily available on the Internet.

The delivery of a material and energy balances course is enhanced through a series of in-class and out-of-class exercises. An active learning classroom is achieved, even at class sizes over 150 students, using multiple instructors in a single classroom, problem solving in teams, problems based on YouTube videos, and just-in-time teaching. To avoid rote copying of the solutions manual, a combination of homework types has proven successful. The implementation of Sapling Learning's online homework has allowed self-directed and personalized problem solving. Traditional paper and pencil homework and multiple choice quizzes round out the weekly homework assignments. The quizzes and online homework allow for just-in-time feedback (i.e., classroom exercises that review concepts from homework completed just hours earlier). Course and exam grades as well as surveys assessed the changes to the course. Timing of the first of three exams is critical to provide a fair assessment and minimize the students withdrawing from the course and likely changing majors. Student surveys show a strong preference for multiple types of homework, especially online homework, to maximize students' learning.

Large amplitude oscillatory shear (LAOS) rheology is often performed in order to complement steady simple shear (SSS) rheology, i.e., probe rheological properties of materials that cannot be not observed with SSS alone. However, it is difficult to measure the SSS rheology of some problematic materials due to fracture and ejection, and LAOS may alleviate these issues, at least partially. Therefore, it is of interest to obtain SSS rheology information from LAOS measurements. We show that a constitutive modeling approach may be used to unify the analysis of LAOS data obtained from different viscometric geometries and modes of control and that the LAOS data may be used to predict SSS profiles. A model elastoviscoplastic material, a Carbopol solution, was used to validate the approach experimentally. LAOS rheometry of problematic biomass slurries was also performed, and the SSS profiles for the slurries were predicted with more confidence than could be obtained from SSS measurements directly.

Personalized, online homework was used to supplement textbook homework, quizzes, and exams for one section of a course in material and energy balances. The objective of this study was to test the hypothesis that students using personalized, online homework earned better grades in the course. The online homework system asks the same questions of each student while changing one or more numeric values in the problem statement. A comparison of performance on common quizzes, exams, and final course grades between students using the textbook and online homeworks versus students completing textbook homework and simple, multiple choice reading quizzes showed a statistically significant increase in achievement for the students using online homework. Of note, 91% of the students using online homework achieved C or better as their final course grade compared with 72% of the students in the control group. Student evaluations show that 66% of the students prefer textbook homework in combination with online homework to maximize learning of the course material.

YouTube Fridays is a teaching tool that devotes the first five minutes of class each Friday to a YouTube video related to the course. Students select the videos, which expand the class's educational content in courses such as thermodynamics and material and energy balances. From assessments of two pilot studies using YouTube Fridays in Chemical Engineering courses, it is clear that the tech-savvy students of the net generation enjoy finding and sharing the videos. The pedagogical value of the activity is obvious, as determined from evaluation of the written reports submitted by the students. Several examples of advanced chemical engineering topics (e.g., the CSTR) have been introduced to sophomore students taking their first chemical engineering course as part of this activity. Overall, this use of technology in the classroom clearly engages the technology-centric students that encompass the majority of college campuses today.