Benefits and Drawbacks of Online Teaching Reading in the Post-COVID-19 Era

The study is based on the research which attempted to investigate the benefits and drawbacks of online teaching reading in the post-COVID-19 era. The objectives of the study were (1) to find out the benefits and drawbacks of online teaching reading in the post-COVID-19 and (2) to find out how the English teacher implements online teaching reading in the post-COVID-19. The researchers selected the VII B class consisting of 21 students and one English teacher of SMP Muhammadiyah 9 Gemuh as the research subjects. This study is qualitative research with a case study as a research method. The instruments of this study were a questionnaire, interviews, and observation. The study revealed that online teaching reading in the post-COVID-19 era had several benefits such as improving students’ engagement, improving students’ understanding, providing a variety of reading materials, and increasing the teacher’s creativity. Besides, the drawbacks faced by the students were unstable internet connectivity, financial issue, and inability to manage time. In addition, the results of the observation and interview showed that the English teacher at SMP Muhammadiyah 9 Gemuh applied a hybrid type of online teaching using four online learning platforms such as Kahoot!, QuizWhizzer, WhatsApp Group, and Google Classroom

Protic Ionic Liquids Used as Metal-Forming Green Lubricants for Aluminum: Effect of Anion Chain Length

Among the applications for protic ionic liquids (PILs), lubrication is one of the newest and the most promising. In this work, ammonium-based protic ionic liquids were tested as lubricant fluids for aluminum-steel contacts. PILs were synthesized with 2-hydroxyethylamine (2HEA) and a carboxylic acid (formic and pentanoic), aiming to understand the effect of two different anion chain lengths on the lubricant behavior. The synthesized PILs were characterized by RMN, FTIR and TGA. Wear tests, conducted using a ball-on-plate configuration, showed that the increase of the anion carbon chain length in the PIL structure reduced significantly the coefficient of friction value. Besides, after the wear tests, the PILs structural integrity was not affected. In the same way, bending under tension (BUT) tests evidenced that the performance for stamping conditions of the PIL with the longest anion carbon chain was similar to that of the commercial lubricant. Since, both formed a uniform tribofilm, developed the same lubrication regime and the drawing forces values were close and constant. Hence, the ionic liquid obtained with 2HEA and pentanoic acid (2HEAPe) is as suitable as the commercial lubricant for metal forming processes

Binary mixtures of ionic liquids in aqueous solution: towards an understanding of their salting-in/salting-out phenomena

The order of the salting-in or salting-out inducing ability of ions on the aqueous solubility of macromolecules in aqueous solutions is known as the Hofmeister series. Taking into account that ionic liquids (ILs) are constituted by ions, they can exert similar effects on the solubility of other ILs in aqueous media. In order to expand the knowledge on the salting-in/-out ability of ILs, experimental studies on the solubility of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonylimide) in water in presence of other IL/salts were conducted at 298.15 K at atmospheric pressure. Both the impact of the anion and cation of the IL were evaluated with the following ILs/salts: 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium hydrogensulfate, cholinium bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and lithium bis(trifluoromethylsulfonyl)imide, in a wide composition range. As happens with common salts, both salting-in and salting-out effects exerted by ILs were observed, with a higher impact exerted by the IL anion on the salting-out phenomenon. These data allow to better understand the ILs impact when designing liquid-liquid separation processes.publishe