Effects of and preference for student- and teacher-implemented good behavior game in early elementary classes.

Disruptive behavior during instruction is a common problem in elementary classrooms. One intervention to reduce disruptive behavior is the Good Behavior Game (GBG). In this study, the students of 2 early elementary classrooms experienced 3 versions of the GBG: experimenter-implemented, teacher-implemented, and student-implemented. The effects of the GBG on disruptive behavior and peer interactions were evaluated using a combined reversal and multielement design. Student preference for conditions was assessed via a group arrangement of a concurrent-chains preference assessment. All versions of the game reduced disruptive behavior compared to baseline, but the rate of disruptive behavior was slightly higher during the teacher-implemented sessions in Class 1. Few peer interactions occurred during the game; however, negative interactions increased slightly in both classes during the GBG. Students overwhelmingly preferred the student-implemented version of the game. This study provides support for student implementation of the GBG and offers an approach to student shared governance in the classroom.

Understanding variability in petroleum jet fuel life cycle greenhouse gas emissions to inform aviation decarbonization.

A pressing challenge facing the aviation industry is to aggressively reduce greenhouse gas emissions in the face of increasing demand for aviation fuels. Climate goals such as carbon-neutral growth from 2020 onwards require continuous improvements in technology, operations, infrastructure, and most importantly, reductions in aviation fuel life cycle emissions. The Carbon Offsetting Scheme for International Aviation of the International Civil Aviation Organization provides a global market-based measure to group all possible emissions reduction measures into a joint program. Using a bottom-up, engineering-based modeling approach, this study provides the first estimates of life cycle greenhouse gas emissions from petroleum jet fuel on regional and global scales. Here we show that not all petroleum jet fuels are the same as the country-level life cycle emissions of petroleum jet fuels range from 81.1 to 94.8 gCO2e MJ-1, with a global volume-weighted average of 88.7 gCO2e MJ-1. These findings provide a high-resolution baseline against which sustainable aviation fuel and other emissions reduction opportunities can be prioritized to achieve greater emissions reductions faster.

Deterministic chaos in the Belousov-Zhabotinsky reaction: Experiments and simulations.

An account of the experimental discovery of complex dynamical behavior in the continuous-flow, stirred tank reactor (CSTR) Belousov-Zhabotinsky (BZ) reaction, as well as numerical simulations based on the BZ chemistry are given. The most recent four- and three-variable models that are deduced from the well-accepted, updated chemical mechanism of the BZ reaction and which exhibit robust chaotic states are summarized. Chaos has been observed in experiments and simulations embedded in the regions of complexities at both low and high flow rates. The deterministic nature of the observed aperiodicities at low flow rates is unequivocally established. However, controversy still remains in the interpretation of certain aperiodicities observed at high flow rates.