HySA/Catalysis has developed Pt‐only materials supported on Vulcan and Ketjenblack carbon, at various Pt loadings in the form of the HySA‐V and HySA‐K series of catalysts. These materials have been proven on both an ex‐situ (TF‐RDE techniques) and in situ (single cell MEA testing) basis to be on par with state‐of‐the‐art commercial benchmark materials. Despite these development achievements high‐performance platinum alloy catalysts that address sluggish oxygen reduction reaction (ORR) kinetics are required in order to minimize the precious metal content and ultimately the cost of fuel cell catalysts. Conveyed in this paper is a systematic investigation of the effect of alloying counterpart deposition sequence on the electrochemical and physical properties of the dealloyed class of advance ORR catalysts at a laboratory synthesis scale. Progression from laboratory scale synthesis to pre‐commercial production is presented and in‐situ single cell performance of scaled dealloyed catalyst materials is given.
We continuously interact with computerized systems to achieve goals and perform tasks in our personal and professional lives. Therefore, the ability to program such systems is a skill needed by everyone. Consequently, computational thinking skills are essential for everyone, which creates a challenge for the educational system to teach these skills at scale and allow students to practice these skills. To address this challenge, we present a novel approach to providing formative feedback to students on programming assignments. Our approach uses dynamic evaluation to trace intermediate results generated by student's code and compares them to the reference implementation provided by their teachers. We have implemented this method as a Python library and demonstrate its use to give students relevant feedback on their work while allowing teachers to challenge their students' computational thinking skills.
This paper describes the influence of concrete compressive strength and specimen size on the fundamental characteristics of the flexural compressive stress-strain distribution. The main variables were specimen size and cylinder compressive strength. A total of 27 concrete specimens were subjected to flexural tests, with specific reference to analysis of the compression stresses, produced by varying two independent loads in a configuration aimed at controlling the strain distribution. These loads generated a condition of zero strain on the one face of the specimen, and a condition of maximum flexural compression strain on the opposite face. From the strain distribution, the stress-strain curves and stress block parameters were determined, and the influence of specimen size on the stress block parameters described using the Modified Size Effect Law (MSLE). Using a modified form of the moment-axial force (M-N) interaction diagram the BS 8110-1 (1997), SANS 0100-1 (2000), ACI-318 (2014) and EN 1992-1-1 (2004) codes of practice were compared for the design of reinforced concrete beams containing South African materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.