Students' Viewpoint: What Constitutes Presence in an Online Classroom?

In this exploratory study, a community of inquiry framework was used to investigate students' perceptions of the efficacy and quality of online information organization and abstracting and indexing classes. It was found that participants valued not only the flexibility of online education, but also the instructor's timely engagement and reflection. Study participants emphasized the necessity of the instructor's frequent engagement through various modes of communication, such as virtual and face-to-face office hours and email. Participants' interest in asynchronous instruction mode was also observed. These findings are in line with previous studies emphasizing the importance of teaching presence in online classrooms. This study contributes to understanding students' perceptions of the quality of online learning and teaching.     

Concentrations and Methods

This study compared 248 graduating seniors with 301 beginning juniors at 10 bachelor's-level social work programs in the Northeast concerning their knowledge and attitudes regarding working with substance-abusing clients. Graduating seniors demonstrated modestly higher levels of knowledge and only slightly more positive attitudes toward working with this population. In a multivariate analysis, however, having taken a substance abuse course in college or training in settings outside of school improved students' attitudes in this regard. The students' ethnic/racial identity and personal exposure to substance abuse through family, close friends, or self also had a significant impact on their knowledge and attitudes.     

Microstructure,mechanical property and corrosion resistance property of Cr26Mo3.5 super ferritic stainless joints by P-TIG and laser welding

The characteristics of microstructure, mechanical property and corrosion behavior of Cr26Mo3.5 super stainless steel joints by pulse tungsten inert gas(P-TIG)welding and laser welding were investigated. The results indicate that the widths of the center equiaxed grain zone(EGZ)and the columnar grain zone(CGZ)increase with the increase of heat input in both welding processes. The precipitates of Nb and Ti carbides and nitrides are formed in the weld metal(WM)and the heat affected zone(HAZ). The joints by laser welding show better tensile and corrosion resistance properties than those by P-TIG welding due to the heat concentration and lower heat input. The tensile strength and elongation increase with the decrease of heat input, and the fracture mode of the joints turns into ductile-brittle mixed fracture from ductile fracture when the welding method turns into P-TIG welding from laser welding. Moreover, the corrosion resistance of all joints declines slightly with the increase of heat input. Hence, laser welding is more suitable for welding Cr26Mo3.5 super stainless steel in engineering applications.