A simulation-based approach for investigating the dynamics of rebound effects in the circular economy: A case of use-oriented product/service system.

Current research in Circular Economy (CE) fails to address the occurrence of Rebound Effects (RE), which are systemic and behavioural responses to the implementation of interventions hindering the potential sustainability benefits. This paper aims to advance the academic discussion and the practical consideration of RE by exploring the potential of using System Dynamics (SD) to enable the ex-ante identification of potential RE of CE initiatives. A five-stage simulation-based approach for the identification and mitigation of potential rebound effects (AIMRE) is proposed. Its application is demonstrated in a use-oriented product/service system (PSS) case focused on a high-end dress rental service. The AIMRE enables the representation of the magnitude and reasons for RE occurrence through 14 scenarios. The finding highlights the importance of considering the interplay between consumers' and companies' decision-making processes in quantifying, understanding, and mitigating RE occurrence.

Barriers to employing digital technologies for a circular economy: A multi-level perspective.

Industry 4.0 and digital technologies might significantly impact resource optimization in a smart circular economy. However, adopting digital technologies is not easy due to barriers that may arise during this process. While prior literature offers initial insights into barriers at the firm level, these studies pay less attention to these barriers' multi-level nature. Focusing only on one particular level while ignoring others may not unleash the full potential of DTs in a circular economy. To overcome barriers, it's necessary to have a systemic understanding of the phenomenon, which is missing in previous literature. By combining a systematic literature review and multiple case studies of nine firms, this study aims to unpack the multi-level nature of barriers to a smart circular economy. The primary contribution of this study is a new theoretical framework composed of eight dimensions of barriers. Each dimension provides unique insights related to the multi-level nature of the smart circular economy transition. In total, 45 barriers were identified and categorized into the following dimensions: 1. Knowledge management (five barriers), 2. Financial (three barriers), 3. Process management & Governance (eight barriers), 4. Technological (ten barriers), 5. Product & Material (three barriers), 6. Reverse logistic infrastructure (four barriers), 7. Social behaviour (seven barriers), and 8. Policy & Regulatory (five barriers). This study examines how each dimension and multi-level barrier affects the transitions toward a smart circular economy. An effective transition copes with complex, multidimensional, multi-level barriers, which might require mobilization beyond a single firm. Government actions need to be more effective and correlated with sustainable initiatives. Policies also should focus on mitigating barriers. Overall, the study contributes to smart circular economy literature by increasing theoretical and empirical understanding of digital transformation barriers towards circularity.

Analysis of national policies for Circular Economy transitions: Modelling and simulating the Brazilian industrial agreement for electrical and electronic equipment.

Public policies, incentives, and infrastructure are top-down instruments that can align stakeholders' roles and expectations for Circular Economy (CE) transitions, but it is crucial to analyse the possible effects of such instruments before implementation. This research investigates the Brazilian Industrial Agreement for Electrical and Electronic Equipment (BIAEEE) that governs the responsibilities and targets for nationwide collection and treatment of Waste from Electrical and Electronic Equipment (WEEE). A system dynamics simulation model is adapted for the use of smartphones in Brazil, and interventions focused on the collection of end-of-life products are examined against the BIAEEE targets. Twelve policy scenarios investigate three aspects of EEE collection: coverage increase, distribution of collection points and rewards. All scenarios show improvement in the EEE collection, but only one meets the BIAEEE targets. This research demonstrates how modelling and simulation can inform strategic decision-making in public policies for CE transitions.

Comparison of the Tei index with invasive measurements of right ventricular function.

The Doppler-derived Tei index has been reported to be clinically useful in assessing global right ventricular function. It could increase in response to combinations of increased pulmonary artery pressure and/or ventricular dysfunction. We compared the Tei index with invasive measurements of right ventricular function during acute pulmonary hypertension. Right and left ventricular pressures, pulmonary and aortic pressures, pulmonary flow and right ventricular volume by sonomicrometry were measured in six anaesthetized sheep. Graded pulmonary arterial hypertension was induced by a mechanical occlusion maneuver. Pressure-volume loops were generated during preload reduction through caval occlusion. Epicardial echocardiograms were also performed. Invasive indexes including preload recruitable stroke work, ventricular diastolic time constant and stiffness constant, and cardiac output were assessed, as were noninvasive echocardiographic indexes including Tei index and E/A ratio. The right ventricular pressure-volume loop became rectangular, with well-defined isovolumic phases. The slope of preload recruitable stroke work was increased significantly during pulmonary pressure of 30 mm Hg. The ventricular time constant showed a significant increase with no change of chamber stiffness during pulmonary pressure of 35 mm Hg. Concomitantly, the Tei index increased significantly from 0.06+/-0.03 to 0.31+/-0.06, together with the shortening of the ejection time and a decrease of the E/A ratio (P<0.05). Thus, the right ventricular Tei index was noted to be affected by acute graded afterload increase. The alteration in invasive measurements of systolic and diastolic function makes the Tei index a sensitive indicator of right ventricular dysfunction in the settings of acute pulmonary hypertension.

Atresia pulmonar con septum interventricular intacto y anomalía de Ebstein de la válvula tricúspide / Pulmonary atresia with intact ventricular septum and Ebstein abnormality of the tricuspid valve

Los enfermos portadores de atresia pulmonar con septum intraventricular intacto tiene una mala evolución con o sin tratamiento quirúrgico. Los mejores resultados operatorios se obtiene en aquellos casos con un ventrículo derecho de tamaño aceptable, con pocos sinusoides intramiocardicos y en ausencia de disfunción significativa de la válvula tricúspide. Presentmos cinco casos de atresia pulmonar con septum intraventricular intacto asociados a disfución de la válvula tricúspide. Este grupo de enfermos tiene un comportamiento clínico a aquellos sin displasia de la válvula tricúspide. Tanto la ecocardiografía como la angiocardiografía son necesarios para el diagnóstico diferencial. La combinación de fístula sístemico-pulmonar con valvulotomía cuando es posible, así como la reconstrucción de la vía de salida del ventrículo derecho están indicadas en la corrección quirúrgica del defecto. El cambio valvular tricuspideo se vuelve necesario en algunos casos

Atresia tricuspidea con atresia pulmonar / Tricuspid atresia associated with pulmonary atresia

Revisamos el cuadro clínico y la evolución a largo plazo de 14 casos de atresia tricuspídea asociada a atresia pulmonar. Con la finalidad de delinear la desición terapeútica analizamos los hallazgos electrocardiográficos, homodinámicos y anatómicos. En este grupo de atresias tricuspídeas, el cuadro clínico depende del tamaño del conducto arterioso. Es frecuente sin embargo que exista pobre tolerancia a la malformación y esta se comporta como las cardiopatías con oligohemia pulmonar (cianosis desde el nacimiento y crisis de hipoxia). Si tomamos en consideración la edad de estos pacientes el procedimiento quirúrgico inicial debe ser la fístula de Blalock-Taussig modificada. La técnica de Fontn y sus variantes deben ser consideradas como una alteración en niños mayores