The Repairing of Misconceptions through the Use of Inquiry-Based Activities

Misconceptions exist in all fields of learning and develop through a person’s preconception of how the world works. Students with misconceptions in chemical engineering are not capable of correctly transferring knowledge to a new situation and will likely arrive at an incorrect solution. The purpose of this thesis was to repair misconceptions in thermodynamics by using inquiry-based activities. Inquiry-based learning is a method of teaching that involves hands-on learning and self-discovery. Previous work has shown inquiry-based methods result in better conceptual understanding by students relative to traditional lectures. The thermodynamics activities were designed to guide students towards the correct conceptual understanding through observing a preconception fail to hold up through an experiment or simulation. The developed activities focus on the following topics in thermodynamics: “internal energy versus enthalpy”, “equilibrium versus steady state”, and “entropy”. For each topic, two activities were designed to clarify the concept and assure it was properly grasped. Each activity was coupled with an instructions packet containing experimental procedure as well as pre- and post-analysis questions, which were used to analyze the effect of the activities on the students’ responses. Concept inventories were used to monitor students’ conceptual understanding at the beginning and end of the semester. The results did not show a statistically significant increase in the overall concept inventory scores for students who performed the activities compared to traditional learning. There was a statistically significant increase in concept area scores for “internal energy versus enthalpy” and “equilibrium versus steady state”. Although there was not a significant increase in concept inventory scores for “entropy”, written analyses showed most students’ misconceptions were repaired. Students transferred knowledge effectively and retained most of the information in the concept areas of “internal energy versus enthalpy” and “equilibrium versus steady state”.

Effect of Participant Gender, Professor Gender, and Activity Interventions on the Understanding of Concepts in Thermodynamics

Misconceptions about heat and temperature have been seen across all educational levels, even in undergraduate engineering courses. One way these misconceptions can be remediated is through instructional methods, such as inquiry-based activities. Performance on assessments in sciences and engineering has been found to vary when gender is taken into consideration. The purpose of the current study was to investigate the effects of participant gender, professor gender, and level of inquiry-based activities on the conceptual understanding of 247 undergraduate engineering students in thermodynamics. A pre-test post-test design was used. Conceptual understanding of thermodynamics was measured by students’ scores on the Concept Inventory for Engineering Thermodynamics (CIET; Vigeant, Prince & Nottis, 2011). Inquiry-based activities were developed by the researchers and given to professors who determined if they would do all, some, or none of them as they taught. Significant differences were found among participants of different gender, different gender of the professor instructing the course, and level of inquiry-based activity. The participants who were exposed to all of the activities provided didsignificantly better on the post-test than those who were only exposed to some or none of the activities. The results from this current study indicated that differences in gender, professorgender, and level of inquiry-based activity has an effect on undergraduate engineering students’ conceptual understanding of thermodynamics. Future research should investigate more factorsthat contribute to lower representation of women in the engineering field.

Efficient Liquid Liquid Extraction By Emulsion Formation and Separation in Robust Milli-Fluidic Devices

Conventional liquid liquid extraction (LLE) methods require large volumes of fluids to achieve the desired mass transfer of a solute, which is unsuitable for systems dealing with a low volume or high value product. An alternative to these methods is to scale down the process. Millifluidic devices share many of the benefits of microfluidic systems, including low fluid volumes, increased interfacial area-to-volume ratio, and predictability. A robust millifluidic device was created from acrylic, glass, and aluminum. The channel is lined with a hydrogel cured in the bottom half of the device channel. This hydrogel stabilizes co-current laminar flow of immiscible organic and aqueous phases. Mass transfer of the solute occurs across the interface of these contacting phases. Using a y-junction, an aqueous emulsion is created in an organic phase. The emulsion travels through a length of tubing and then enters the co-current laminar flow device, where the emulsion is broken and each phase can be collected separately. The inclusion of this emulsion formation and separation increases the contact area between the organic and aqueous phases, therefore increasing the area over which mass transfer can occur. Using this design, 95% extraction efficiency was obtained, where 100% is represented by equilibrium. By continuing to explore this LLE process, the process can be optimized and with better understanding may be more accurately modeled. This system has the potential to scale up to the industrial level and provide the efficient extraction required with low fluid volumes and a well-behaved system.