Search for: All records

The transition to a circular economy (CE) requires agents in circular supply chain (SC) networks to take a variety of different initiatives, many of which are dynamic in nature. We use a system dynamics (SD)-based approach to develop a generic framework for dynamic modeling of CE networks and propose a prototypical circular SC network by combining dynamic models for five actors: a manufacturer, consumer, material recovery facility (MRF), recycling facility, and the Earth. We apply this framework to the supply chain for Polyethylene Terephthalate (PET) plastic packaging by considering different scenarios over a 65-year time horizon in the US. We include both slow-down-the-loop initiatives (i.e., those that extend product use time through demand reduction or reuse) and close-the-loop initiatives (i.e., those that reintroduce product to the supply chain through recycling) by the consumer, as well as sorting and recycling capacity expansion. We find that, given the current recycling infrastructure in the U.S., slow-down-the-loop initiatives are more effective than close-the-loop initiatives for improving circularity and minimizing environmental impact. However, combining the two initiatives eliminates the need for capacity expansion and leads to the highest circularity in the shortest amount of time. 

This article captures a convergence of its authors’ life experiences and existent data, made possible by Complex Instruction (CI). There is a pressing need to study and support the foundational practice of assigning competence, which requires that a teacher first recognise students’ strengths and publicly name their academic contributions. However, a teacher cannot name what they have not noticed. Collectively, we wondered what we could learn from one teacher’s fluid ability to effectively assign competence. We embraced CI principles to co-author our article. 

In February 2023, a train derailment in Ohio caused a chemical spill and fires releasing contaminants into the air, soil, waterways, and buildings.