Search for: All records

Over the past year we continued, under support from the NSF Division of Undergraduate Education, to emphasize implementation of Low-Cost Desktop Learning Modules LCDLMs for fluid mechanics, heat transfer and biomedical applications. Here we present implementation data from concept tests and surveys, details on new designs and insights gained. Through these activities our team progressed beyond original expectations that were outlined in our original set of NSF-sponsored objectives. We analyzed data from several institutions added from the south central and mid-eastern portions of the US through a combined University of ***-L** and -P** training hub conducted in a virtual mode held in September 2020 with regional communications spearheaded by respective faculty from these institutions. Much of the data analyzed results from support through a 2020 NSF supplement where we engaged in a study to compare direct hands-on implementations of LCDLMs to virtual synchronous and asynchronous implementations augmented with short conceptual videos, a tact necessary because of COVID-19 in-person restrictions. Surprisingly, both in-person and virtual modes show similar conceptual gains. A publication is being developed with intent for submission to the International Journal of Engineering Education where we compare the virtual and in-person modes of instruction. We added a few more institutions through a northeastern training hub held in August 2021 with faculty from the University of *** managing regional communications; again, this hub was held virtually given uncertainty about the lifting of COVID-19 related restrictions. Regarding new LCDLMs we added a shell and tube heat exchanger and fabricated a large number for distribution and implementation and began analyzing conceptual gains and survey results. We prototyped a new evaporative cooler and continue to develop new broader impact units to demonstrate stenosis in an artery and blood cell separations and began implementing them in the classroom. Regarding LCDLM publications a paper was published in Chemical Engineering Education on a study where we compare heat transfer data for the miniature double pipe heat exchanger to predictions based on correlations for industrial scale heat exchangers and included classroom assessment data. 

One of the current difficulties limiting the use of adoptive cell therapy (ACT) for cancer treatment is the lack of methods for rapidly expanding T cells. As described in the present report, we developed a centrifugal bioreactor (CBR) that may resolve this manufacturing bottleneck. The CBR operates in perfusion by balancing centrifugal forces with a continuous feed of fresh medium, preventing cells from leaving the expansion culture chamber while maintaining nutrients for growth. A bovine CD8 cytotoxic T lymphocyte (CTL) cell line specific for an autologous target cell infected with a protozoan parasite,Theileria parva, was used to determine the efficacy of the CBR for ACT purposes. Batch culture experiments were conducted to predict how CTLs respond to environmental changes associated with consumption of nutrients and production of toxic metabolites, such as ammonium and lactate. Data from these studies were used to develop a kinetic growth model, allowing us to predict CTL growth in the CBR and determine the optimal operating parameters. The model predicts the maximum cell density the CBR can sustain is 5.5 × 10⁷ cells/mL in a single 11‐mL conical chamber with oxygen being the limiting factor. Experimental results expanding CTLs in the CBR are in 95% agreement with the kinetic model. The prototype CBR described in this report can be used to develop a CBR for use in cancer immunotherapy.

 

This work is focused on designing an easy‐to‐use novel perfusion system for articular cartilage (AC) tissue engineering and using it to elucidate the mechanism by which interstitial shear upregulates matrix synthesis by articular chondrocytes (AChs). Porous chitosan‐agarose (CHAG) scaffolds were synthesized and compared to bulk agarose (AG) scaffolds. Both scaffolds were seeded with osteoarthritic human AChs and cultured in a novel perfusion system with a medium flow velocity of 0.33 mm/s corresponding to 0.4 mPa surfice shear and 40 mPa CHAG interstitial shear. While there were no statistical differences in cell viability for perfusion versus static cultures for either scaffold type, CHAG scaffolds exhibited a 3.3‐fold higher (p < 0.005) cell viability compared to AG scaffold cultures. Effects of combined superficial and interstitial perfusion for CHAG showed 150‐ and 45‐fold (p < 0.0001) increases in total collagen (COL) and 13‐ and 2.2‐fold (p < 0.001) increases in glycosaminoglycans (GAGs) over AG non‐perfusion and perfusion cultures, respectively, and a 1.5‐fold and 3.6‐fold (p < 0.005) increase over non‐perfusion CHAG cultures. Contrasting CHAG perfusion and static cultures, chondrogenic gene comparisons showed a 3.5‐fold increase in collagen type II/type I (COL2A1/COL1A1) mRNA ratio (p < 0.05), and a 1.3‐fold increase in aggrecan mRNA. Observed effects are linked to NF‐κB signal transduction pathway inhibition as confirmed by a 3.2‐fold (p < 0.05) reduction of NF‐κB mRNA expression upon exposure to perfusion. Our results demonstrate that pores play a critical role in improving cell viability and that interstitial flow caused by medium perfusion through the porous scaffolds enhances the expression of chondrogenic genes and extracellular matrix through downregulating NF‐κB1.

 

Hands-on experiments using the Low-Cost Desktop Learning Modules (LCDLMs) have been implemented in dozens of classrooms to supplement student learning of heat transfer and fluid mechanics concepts with students of varying prior knowledge. The prior knowledge of students who encounter these LCDLMs in the classroom may impact the degree to which students learn from these interactive pedagogies. This paper reports on the differences in student cognitive learning between groups with low and high prior knowledge of the concepts that are tested. Student conceptual test results for venturi, hydraulic loss, and double pipe heat exchanger LCDLMs are analyzed by grouping the student data into two bins based on pre-test score, one for students scoring below 50% and another for those scoring above and comparing the improvement from pretest to posttest between the two groups. The analysis includes data from all implementations of each LCDLM for the 2020-2021 school year. Results from each of the three LCDLMs were analyzed separately to compare student performance on different fluid mechanics or heat exchanger concepts. Then, the overall pre- and posttest scores for all three LCDLMs were analyzed to examine how this interactive pedagogy impacts cognitive gains. Results showed statistically significant differences in improvement between low prior knowledge groups and high prior knowledge groups. Additional findings showed statistically significant results suggesting that the gaps in performance between low prior knowledge and high prior knowledge groups on pre-tests for the LCDLMs were decreased on the posttest. Findings showed that students with lower prior knowledge show a greater overall improvement in cognitive gains than those with higher prior knowledge on all three low-cost desktop learning modules. 

Our team has developed Low-Cost Desktop Learning Modules (LCDLMS) as tools to study transport phenomena aimed at providing hands-on learning experiences. With an implementation design embedded in the community of inquiry framework, we disseminate units to professors across the country and train them on how to facilitate teacher presence in the classroom with the LC-DLMs. Professors are briefed on how create a homogenous learning environment for students based on best-practices using the LC-DLMs. By collecting student cognitive gain data using pre/posttests before and after students encounter the LC-DLMs, we aim to isolate the variable of the professor on the implementation with LC-DLMs. Because of the onset of COVID-19, we have modalities for both hands-on and virtual implementation data. An ANOVA whereby modality was grouped and professor effect was the independent variable had significance on the score difference in pre/posttest scores (p<0.0001) and on posttest score only (p=0.0004). When we divide out modality between hands-on and virtual, an ANOVA with an Ftest using modality as the independent variable and professor effect as the nesting variable also show significance on the score difference between pre and posttests (p-value=0.0236 for handson, and p-value=0.0004 for virtual) and on the posttest score only (p-value=0.0314 for hands-on, and p-value<0.0001 for virtual). These results indicate that in all modalities professor had an effect on student cognitive gains with respect to differences in pre/posttest score and posttest score only. Future will focus on qualitative analysis of features of classrooms yield high cognitive gains in undergraduate engineering students. 

The development of tools that promote active learning in engineering disciplines is critical. It is widely understood that students engaged in active learning environments outperform those taught using passive methods. Previously, we reported on the development and implementation of hands-on Low-Cost Desktop Learning Modules (LCDLMs) that replicate real-world industrial equipment which serves to create active learning environments. Thus far, miniaturized venturi meter, hydraulic loss, and double-pipe and shell & tube heat exchanger DLMs have been utilized by hundreds of students across the country. It was demonstrated that the use of DLMs in face-to-face classrooms results in statistically significant improvements in student performance as well as increases in student motivation compared to students taught in a traditional lecture-only style classroom. Last year, participants in the project conducted 45 implementations including over 600 DLMs at 24 universities across the country reaching more than 1,000 students. In this project, we report on the significant progress made in broad dissemination of DLMs and accompanying pedagogy. We demonstrate that DLMs serve to increase student learning gains not only in face-toface environments but also in virtual learning environments. Instructional videos were developed to aid in DLM-based learning during the COVID-19 pandemic when instructors were limited to virtual instruction. Preliminary results from this work show that students working with DLMs even in a virtual setting significantly outperform those taught without DLM-associated materials. Significant progress has also been made on the development of a new DLM cartridge: a see-through 3Dprinted miniature fluidized bed. The new 3D printing methodology will allow for rapid prototyping and streamlined development of DLMs. A 3D-printed evaporative cooling tower DLM will also be developed in the coming year. In October 2020, the team held a virtual implementers workshop to train new participating faculty in DLM use and implementation. In total, 13 new faculty participants from 10 universities attended the 6-hour, 2- day workshop and plan to implement DLMs in their classrooms during this academic year. In the last year, this project was disseminated in 8 presentations at the ASEE Virtual Conference (June 2020) and American Institute of Chemical Engineers Annual Conference (November 2019) as well as the AIChE virtual Community of Practice Labs Group and a seminar at a major university, ultimately disseminating DLM pedagogy to approximately 200 individuals including approximately 120 university faculty. Further, the former group postdoc has accepted an instructor faculty position at University of Wisconsin Madison where she will teach unit operations among other subjects; she and the remainder of the team believe the LCDLM project has prepared her well for that position. In the remaining 2.5 years of the project, we will continue to evaluate the effectiveness of DLMs in teaching key heat transfer and fluid dynamics concepts thru implementations in the rapidly expanding pool of participating universities. Further, we continue our ongoing efforts in creating the robust support structure necessary for large-scale adoption of hands-on educational tools for promotion of hands-on interactive student learning. 

The 2020 coronavirus pandemic necessitated the transition of courses across the United States from in-person to a virtual format. Effective delivery of traditional, lecture-based courses in an online setting can be difficult and determining how to best implement hands-on pedagogies in a virtual format is even more challenging. Interactive pedagogies such as hands-on learning tools, however, have proven to significantly enhance student conceptual understanding and motivation; therefore, it is worthwhile to adapt these activities for virtual instruction. Our team previously developed a number of hands-on learning tools called Low-Cost Desktop Learning Modules (LCDLMs) that demonstrate fluid mechanics and heat transfer concepts—traditionally utilized by student groups in a classroom setting, where they perform qualitative and quantitative experiments and interactively discuss conceptual items. In this paper we examined the transition of the LCDLM hands-on pedagogy to an entirely virtual format, focusing on a subset of results with greater detail to be shown at the ASEE conference as we analyze additional data. To aid the virtual implementations, we created a number of engaging videos under two major categories: (1) demonstrations of each LCDLM showing live data collection activities and (2) short, animated, narrated videos focused on specific concepts related to learning objectives. In this paper we present preliminary results from pre- and post- implementation conceptual assessments for the hydraulic loss module and motivational surveys completed for virtual implementations of LCDLMs and compare them with a subset of results collected during hands-on implementations in previous years. Significant differences in conceptual understanding or motivation between hands-on and virtual implementations are discussed. This paper provides useful, data-driven guidance for those seeking to switch hands-on pedagogies to a virtual format