The Effect of Grade Point Average on Undergraduates' Understanding of Heat Transfer

Engineering students continue to develop and show misconceptions due to prior knowledge and experiences (Miller, Streveler, Olds, Chi, Nelson, & Geist, 2007). Misconceptions have been documented in students’ understanding of heat transfer(Krause, Decker, Niska, Alford, & Griffin, 2003) by concept inventories (e.g., Jacobi,Martin, Mitchell, & Newell, 2003; Nottis, Prince, Vigeant, Nelson, & Hartsock, 2009). Students’ conceptual understanding has also been shown to vary by grade point average (Nottis et al., 2009). Inquiry-based activities (Nottis, Prince, & Vigeant, 2010) haveshown some success over traditional instructional methods (Tasoglu & Bakac, 2010) in altering misconceptions. The purpose of the current study was to determine whether undergraduate engineering students’ understanding of heat transfer concepts significantly changed after instruction with eight inquiry-based activities (Prince & Felder, 2007) supplementing instruction and whether students’ self reported GPA and prior knowledge, as measured by completion of specific engineering courses, affected these changes. The Heat and Energy Concept Inventory (Prince, Vigeant, & Nottis, 2010) was used to assess conceptual understanding. It was found that conceptual understanding significantly increased from pre- to post-test. It was also found that GPA had an effect on conceptual understanding of heat transfer; significant differences were found in post-test scores onthe concept inventory between GPA groups. However, there were mixed results when courses previously taken were analyzed. Future research should strive to analyze how prior knowledge effects conceptual understanding and aim to reduce the limitations of the current study such as, sampling method and methods of measuring GPA and priorknowledge.

Gold Phosphonates as Transfer Agents in Palladium Catalyzed Hirao Reactions

Through a cross-coupling reaction, aryl phosphonates are produced in high yields when the corresponding aryl bromides are reacted with a gold phosphorylating agent in the presence of a palladium catalyst and an appropriate ligand. To the best of our knowledge, this transformation is the first example involving the transfer of a phosphonate functional group from a gold complex to palladium that has been reported. Throughout the investigation, three gold phosphorylating agents were screened for activity towards the phosphorylation of aryl bromides. Aryl bromides with electrondonating and electron-withdrawing groups were successfully employed in the crosscoupling reactions. All cross-coupling reactions were carried out in THF at room temperature (25ºC) or in a microwave reactor (CEM Discover) at 60ºC for 30 or 60 minutes. The effects of changing reaction parameters such as time, temperature, catalyst and free ligand loading have been investigated. All aryl bromide substrates tested in the cross-coupling reactions produced phosphorylated products.