Cost versus environment? Combined life cycle,techno-economic,and circularity assessment of silicon- and perovskite-based photovoltaic systems

Photovoltaics will play a key role in future energy systems, but their full potential may not be realized until their life cycles are optimized for circularity and overall sustainability. Methods that quantify flows of compound and minor element mixtures, rather than non-mixed elemental flows, are needed to prospectively analyze and predict inventory and performance for complex technology life cycles. This study utilizes process simulation to resolve the mass and energy balances needed to rigorously analyze these complexities in circular systems. Using physics-based prospective inventory data, we simultaneously assess the environmental and techno-economic performance of three photovoltaic life cycles and predict the effects of circularity on resource efficiency, carbon footprint, and levelized cost of electricity. One inventory dataset is generated per life cycle to ensure alignment between assessments and to identify trade-offs between environmental and techno-economic performance with respect to circularity, so linking circularity and sustainability. The linked material and energy resource and techno-economic models allow for the impacts of carbon taxation and the moderating effects of circularity to be explored. In addition to the clear environmental benefits of increased circularity, we find that it could dampen the cost impact of taxation. While confirming that perovskite-based modules, single junction or in tandem with silicon, clearly outperform the silicon market standard both techno-economically and environmentally, we show that maximum circularity does not automatically deliver the most sustainable outcome. The approach enables assessment of the combined impacts of specific technological, commercial, and policy choices made by different actors along the photovoltaic value chain. This article met the requirements for a gold–gold JIE data openness badge described at http://jie.click/badges .      

Proposed follow up programme after curative resection for lower third oesophageal cancer

Cyclins are indispensable elements of the cell cycle and derangement of their function can lead to cancer formation. Recent studies have also revealed more mechanisms through which cyclins can express their oncogenic potential. This review focuses on the aberrant expression of G1/S cyclins and especially cyclin D and cyclin E; the pathways through which they lead to tumour formation and their involvement in different types of cancer. These elements indicate the mechanisms that could act as targets for cancer therapy.