Case studies (CS) attempt to help students increase critical thinking skills and engagement while working through a real-life scenario in various disciplines, including medicine, law, and business. However, the CS method has not been heavily utilized in biological sciences. The present study investigated the effect of the CS method on undergraduate biology students’ conceptual understanding, academic outcomes, and perspectives. A case study was applied in a one-semester undergraduate biology course, which was compared to ten semesters of standard sections. Participants completed course pre- and post-tests, pre- and post-case tests, and an online survey to assess their conceptual understanding and engagement. The initial lowest quartiles were determined from the individual course pre-test scores, which were lower than class averages. Results suggested that the CS method helped students in learning outcomes, critical thinking, and conceptual understanding toward biology. In post-test learning gains, the CS group did 20% better than the non-CS group, with the largest benefit seen in the initially lowest pre-test quartile of the class. Moreover, post-case learning gains were 55% improved in the case test. Survey results indicated that students had positive attitudes toward CS for their engagement in plant biology content. Overall, the distribution of A grades improved by 2.6-fold from standard to CS groups. We conclude that the use of CS may address course content engagement and have the potential to effectively boost academic performance, especially for the initially lowest quartile in undergraduate plant biological sciences courses.
Hiroyuki Inoue, Yasuhiro Watanabe, Jaeyeop Chung
et al.
Abstract In this study, elemental recovery was performed using phase separation from simulated high‐level radioactive waste (HLW) glass. To cause phase separation, SiO 2 and B 2 O 3 were added to the simulated HLW glass and adjusted the ratio of SiO 2 : B 2 O 3 : other oxides to 40:50:10. The phase separated glass was immersed in aqueous solutions of 0–3 mol/L of HNO 3 , H 2 SO 4 , and a 1:1 mixture of HCl–HNO 3 at 363 K for 20 h, and the dissolution behavior of 17 elements was examined. The relationship between the dissolved mass fraction of each element and the acid concentration in the immersion liquid could be approximated by the modified sigmoid function. The recovery of stable nuclei Se, Zr, Pd, and Cs instead of long‐lived radioactive nuclei was tested using a four‐stage leaching process in which the sample was immersed sequentially in four aqueous solutions at 363 K of distilled water, HNO 3 , H 2 SO 4 , and a 1:1 mixture of HCl–HNO 3 for 20 h. It was confirmed that Se, Zr, Pd, and Cs could be recovered selectively. Furthermore, the recovery result could be predicted based on the individual dissolution results described above.
AbstractInhaltsübersicht. Die Verbindungen K2MnS2, Rb2MnS2, Cs2MnS2, K2MnSe2, Rb2MnSe2, Cs2MnSe2, K2MnTe2, Rb2MnTe2 und Cs2MnTe2 wurden durch Umsetzungen von Alkalimetall‐carbonaten mit Mangan bzw. Mangantellurid in einem mit Chalkogen beladenen Wasserstoffstrom erhalten.Kristallstrukturuntersuchungen an Einkristallen ergaben, daß alle neun Verbindungen isotyp kristallisieren (K2ZnO2‐Typ, Raumgruppe Ibam).Untersuchungen zum magnetischen Verhalten zeigen antiferromagnetische Kopplungen der Manganionen in den [MnX4/22–]‐Ketten,On Alkali Metal Manganese Chalcogenides A2MnX2 with A K, Rb, or Cs and X S, Se, or TeThe compounds K2MnS2, Rb2MnS2, Cs2MnS2, K2MnSe2, Rb2MnSe2, Cs2MnSe2, K2MnTe2, Rb2MnTe2, and Cs2MnTe2 were synthesized by the reaction of alkali metal carbonates with Mn or MnTe in a stream of hydrogen charged with chalcogen.Structural investigations on single crystals show that all nine compounds crystallize in isotypic atomic arrangements (K2ZnO2 type, space group Ibam).The magnetic behaviour indicates antiferromagnetic interactions of the manganese ions within the [MnX1/22–] chains.