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Aerodynamic breakup of vaporizing drops is commonly seen in many spray applications. While it is well known that vaporization can modulate interfacial instabilities, the impact of vaporization on drop aerobreakup is poorly understood. Detailed interface-resolved simulations were performed to systematically study the effect of vaporization, characterized by the Stefan number, on the drop breakup and acceleration for different Weber numbers and density ratios. It is observed that the resulting asymmetric vaporization rates and strengths of Stefan flow on the windward and leeward sides of the drop hinder bag development and prevent drop breakup. The critical Weber number thus generally increases with the Stefan number. The modulation of the boundary layer also contributes to a significant increase of drag coefficient. Numerical experiments were performed to affirm that the drop volume reduction plays a negligible role and the Stefan flow is the dominant reason for the breakup suppression and drag enhancement observed. 

This paper analyzes the computational practices that four 7th and 8th grade students engaged in when learning geometric transformations in two different online block-based programming environments. The data sources include video footage of students’ interviews in Zoom where they shared their screens and cameras. The findings determined that students utilized in particular, decomposition and pattern recognition as important computational thinking practices required for learning in STEM disciplines. The paper also describes the changes made in how research method, data collection, and analysis configured opportunities to study computational thinking in remote locations due to the restrictions brought on by COVID-19. We identified three main challenges in the transition to online research: (a) recruiting research participants which included instituting necessary revisions to ethics protocols; (b) rethinking data gathering and analysis techniques along with interactions with participants in virtual settings; (c) dealing with glitches associated with technologies and virtual communication media in just-in-time ways. We conclude that even given the challenges with researching during COVID-19, there are still opportunities for rich, robust research in online settings.