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While perovskite photovoltaic (PV) devices are on the verge of commercialization, promising methods to recycle or remanufacture fully encapsulated perovskite solar cells (PSCs) and modules are still missing. Through a detailed life-cycle assessment shown in this work, we identify that the majority of the greenhouse gas emissions can be reduced by re-using the glass substrate and parts of the PV cells. Based on these analytical findings, we develop a novel thermally assisted mechanochemical approach to remove the encapsulants, the electrode, and the perovskite absorber, allowing reuse of most of the device constituents for remanufacturing PSCs, which recovered nearly 90% of their initial performance. Notably, this is the first experimental demonstration of remanufacturing PSCs with an encapsulant and an edge-seal, which are necessary for commercial perovskite solar modules. This approach distinguishes itself from the "traditional" recycling methods previously demonstrated in perovskite literature by allowing direct reuse of bulk materials with high environmental impact. Thus, such a remanufacturing strategy becomes even more favorable than recycling, and it allows us to save up to 33% of the module's global warming potential. Remarkably, this process most likely can be universally applied to other PSC architectures, particularly n-i-p-based architectures that rely on inorganic metal oxide layers deposited on glass substrates. Finally, we demonstrate that the CO2-footprint of these remanufactured devices can become less than 30 g/kWh, which is the value for state-of-the-art c-Si PV modules, and can even reach 15 g/kWh assuming a similar lifetime.
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The psychological burden of conflict-induced displacement is severe. Currently, there are 80 million displaced persons around the world, and their number is expected to increase in upcoming decades. Yet, few studies have systematically assessed the effectiveness of programs that assist displaced persons, especially in settings of extreme vulnerability. We focus on eastern Democratic Republic of Congo, where myriad local armed conflicts have driven cycles of displacement for over 20 years. We conducted a within-village randomized field experiment with 976 households, across 25 villages, as part of the United Nations' Rapid Response to Population Movements program. The program provided humanitarian relief to over a million people each year, including vouchers for essential nonfood items, such as pots, pans, cloth, and mattresses. The vouchers led to large improvements in psychological well-being: a 0.32 standard deviation unit (SDU) improvement at 6 weeks, and a 0.18 SDU improvement at 1 year. There is no evidence that the program undermined social cohesion within the village, which alleviates worries related to programs that target some community members but not others. Finally, there was no improvement in child health.
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The Dodd Frank Act was passed by the US Congress in July 2010 and included a provision-Section 1502-that aimed to break the link between conflict and minerals in the Eastern Democratic Republic of Congo. To date there is only one rigorous quantitative analysis that investigates the impact of Dodd-Frank on local conflict events. Looking at the short-term impact (2011-2012), it finds that the policy backfired. This study builds on a larger, more representative, dataset of mining sites and extends the time horizon by three years (2013-2015). The results indicate that the policy also backfired in the longer run, especially in areas home to gold mines. For territories with the average number of gold mines, the introduction of Dodd-Frank increased the incidence of battles with 44%; looting with 51% and violence against civilians with 28%, compared to pre-Dodd Frank averages. Delving deeper into the impact of the conflict minerals legislation is important, as President Trump suspended the legislation in February 2017 for a two-year period, ordering his administration to replace it with another policy.
Assuntos
Conflitos Armados , Mineração/legislação & jurisprudência , Políticas , Violência , Conflitos Armados/legislação & jurisprudência , República Democrática do Congo , Ouro , Humanos , Chuva , Tumultos , Estados Unidos , Violência/legislação & jurisprudênciaRESUMO
Laboratory experiments offer an opportunity to isolate human behaviors with a level of precision that is often difficult to obtain using other (survey-based) methods. Yet, experimental tasks are often stripped of any social context, implying that inferences may not directly map to real world contexts. We randomly allocate 632 individuals (grouped randomly into 316 dyads) from small villages in Sierra Leone to four versions of the ultimatum game. In addition to the classic ultimatum game, where both the sender and receiver are anonymous, we reveal the identity of the sender, the receiver or both. This design allows us to explore how fairness behavior is affected by social context in a natural setting where players are drawn from populations that are well-acquainted. We find that average offers increase when the receiver's identity is revealed, suggesting that anonymous ultimatum games underestimate expected fair offers. This study suggest that researchers wishing to relate laboratory behavior to contexts in which the participants are well-acquainted should consider revealing the identities of the players during game play.
Assuntos
Comportamento Cooperativo , Jogos Experimentais , Comportamento Social , Meio Social , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Serra Leoa , Adulto JovemRESUMO
The literature documents a positive association between democracy and health, and studies supporting this claim have largely relied on cross-country panel analyses. In many developing countries, however, local traditional leaders at the micro-level play a key role in individuals' daily lives while the influence of the national government is largely negligible. In response, this study revisits the relationship between democracy and health using micro-level household data from 816 randomly selected villages in Eastern Congo. We find little or no evidence that health outcomes are better in villages that are governed by elected leaders compared to villages where leaders are not elected. Our data suggest that efforts to improve health outcomes in this setting may need to focus on issues such as gender discrimination and education.