Crystalline silicon comprises 90% of the global photovoltaics (PV) market and has sustained a nearly 30% cumulative annual growth rate, yet comprises less than 2% of electricity capacity. To sustain ...this growth trajectory, continued cost and capital expenditure (capex) reductions are needed. Thinning the silicon wafer well below the industry-standard 160 μm, in principle reduces both manufacturing cost and capex, and accelerates economically-sustainable expansion of PV manufacturing. In this analysis piece, we explore two questions surrounding adoption of thin silicon wafers: (a) What are the market benefits of thin wafers? (b) What are the technological challenges to adopt thin wafers? In this analysis, we re-evaluate the benefits and challenges of thin Si for current and future PV modules using a comprehensive technoeconomic framework that couples device simulation, bottom-up cost modeling, and a sustainable cash-flow growth model. When adopting an advanced technology concept that features sufficiently good surface passivation, the comparable efficiencies are achievable for both 50 μm wafers and 160 μm ones. We then quantify the economic benefits for thin Si wafers in terms of poly-Si-to-module manufacturing capex, module cost, and levelized cost of electricity (LCOE) for utility PV systems. Particularly, LCOE favors thinner wafers for all investigated device architectures, and can potentially be reduced by more than 5% from the value of 160 μm wafers. With further improvements in module efficiency, an advanced device concept with 50 μm wafers could potentially reduce manufacturing capex by 48%, module cost by 28%, and LCOE by 24%. Furthermore, we apply a sustainable growth model to investigate PV deployment scenarios in 2030. It is found that the state-of-the-art industry concept could not achieve the climate targets even with very aggressive financial scenarios, therefore the capex reduction benefit of thin wafers is advantageous to facilitate faster PV adoption. Lastly, we discuss the remaining technological challenges and areas for innovation to enable high-yield manufacturing of high-efficiency PV modules with thin Si wafers.
This technoeconomic analysis revisits the concept of thin silicon wafer for its potential cost benefits and technological challenges.
Self-managed abortion: A systematic scoping review Moseson, Heidi; Herold, Stephanie; Filippa, Sofia ...
Baillière's best practice & research. Clinical obstetrics & gynaecology/Baillière's best practice and research in clinical obstetrics and gynaecology,
February 2020, 2020-Feb, 2020-02-00, 20200201, Volume:
63
Journal Article
Peer reviewed
Open access
Self-managed abortion, when a person performs their own abortion without clinical supervision, is a model of abortion care used across a range of settings. To provide a comprehensive synthesis of the ...available literature on self-managed abortion, we conducted a systematic search for peer-reviewed research in April 2019 in PubMed, Embase, Web of Science, Popline, PsycINFO, Google Scholar, Scielo, and Redalyc. We included studies that had a research question focused on self-managed abortion; and were published in English or Spanish. The combined search returned 7167 studies; after screening, 99 studies were included in the analysis. Included studies reported on methods, procurement, characteristics of those who self-managed, effectiveness, safety, reasons for self-managed abortion, and emotional and physical experiences. Numerous abortion methods were reported, most frequently abortion with pills and herbs. Studies reporting on self-managed medication abortion reported high-levels of effectiveness. We identify gaps in the research, and make recommendations to address those gaps.
•Studies reported on a wide range of methods of self-managed abortion.•There is little evidence documenting safety or efficacy of nonmedication methods.•Definitions of self-managed abortion safety and efficacy varied.•People prefer self-management over facility-based abortion for unique reasons.•Emotional and physical experiences of self-management need further study.
Following delivery, extremely premature infants are vulnerable to rapid development of hypothermia and hypoglycemia. To reduce local rates of these morbidities, a multidisciplinary team developed a ...protocol standardizing evidence-based care practices during the first hour after birth.
Using quality improvement methodology, the Golden Hour protocol was implemented for all inborn infants <27 weeks' gestation. Data were collected (2012-2017) over three phases; pre-protocol (n = 80), Phase I (n = 42), and Phase II (n = 92).
There were no significant differences in infant characteristics. Improvements in hypothermia (59% vs 26% vs 38%; p = 0.001), hypoglycemia (18% vs 7% vs 4%; p = 0.012), and minutes to completion of stabilization median (Q1,Q3) 110 (89,138) vs 111 (94,135) vs 92 (74,129); p = 0.0035 were observed.
Implementation of an evidence-based, Golden Hour protocol is an effective intervention for reducing hypothermia and hypoglycemia in extremely premature infants.
The disposal of apoptotic bodies by professional phagocytes is crucial to effective inflammation resolution. Our ability to improve the disposal of apoptotic bodies by professional phagocytes is ...impaired by a limited understanding of the molecular mechanisms that regulate the engulfment and digestion of the efferocytic cargo. Macrophages are professional phagocytes necessary for liver inflammation, fibrosis, and resolution, switching their phenotype from proinflammatory to restorative. Using sterile liver injury models, we show that the STAT3-IL-10-IL-6 axis is a positive regulator of macrophage efferocytosis, survival, and phenotypic conversion, directly linking debris engulfment to tissue repair.
A techno-economic analysis of perovskite-silicon tandem solar modules is presented, outlining the most viable pathway for designing cost-effective, commercially viable tandems. We explore the ...cost-performance trade-off for silicon bottom cells in perovskite-silicon tandems, and evaluate the potential of using low-cost, lower-efficiency silicon bottom cells, on the basis of levelized cost of electricity (LCOE), compared to the higher-efficiency, higher-cost bottom cells that have been the primary focus of most perovskite-silicon tandem research efforts. We fabricate a cost-effective four-terminal silicon-perovskite tandem using a low-cost multicrystalline bottom cell and calculate the device LCOE. We then extend this analysis by modeling performance and LCOE of similar tandems instead using high-efficiency silicon bottom cells, enabling direct comparison of a low-cost and a high-efficiency tandem. Lastly parametric analyses are performed to more broadly examine the bottom-cell cost-performance trade-off. We show that low-cost silicon, even at the detriment of efficiency, is the more likely path to make perovskite-silicon tandems commercially viable and enable future reductions in LCOE, given both current and near-future silicon technology. We lay out a clear economic motivation for pursuing low-cost silicon bottom cells in perovskite-silicon tandems, showing that they can achieve a 15-20% relative LCOE reduction compared to the single-junction sub-cells. This is a 2-3 times greater relative LCOE reduction compared with using high-efficiency silicon. Furthermore, we show that the advantage of using low-cost silicon bottom cells is robust to and benefits from expected market trends, such as falling system costs and advanced, low-cost manufacturing. This work provides a clear pathway to cost-effective tandems, outlines the benefits for existing multicrystalline silicon manufacturers to investing in tandem development, and points out a clear mismatch between commercial viability and current research efforts.
A techno-economic analysis of perovskite-silicon tandem solar modules is presented, outlining the most viable pathway for designing cost-effective, commercially viable tandems.
Abstract
Increasing research on the humanitarian sector examines how its organizational cultures affect both aid outcomes and humanitarian workers’ private lives. The #MeToo movement and several ...public scandals have brought to light patterns of sexual violence in crisis zones perpetrated by humanitarian aid workers; surveys suggest rates of sexual assault within the humanitarian community comparable to, if not higher than, those on US college campuses. How do the conditions that produce sexual violence persist in a sector governed by strong, mission-centric principles, professional codes of conduct, and oversight?
This article uses participant observation in Iraq and Uganda, in-depth interviews, and textural analysis to examine the social origins of sexual violence in humanitarian communities. It builds on studies of aid organizations to argue that the humanitarian sector operates similarly to a “total institution” (Goffman 1961). Then, it draws upon recent work on sexual violence to demonstrate how within-sector social ecologies and informal socialization practices create the conditions of possibility for sexual violence. It identifies two key factors that constitute the emergency aid world—sexual scripts and projects, and sector-specific sexual geographies—and argues that they produce conditions that facilitate sexual violence while labeling them “just how things are done.”
This qualitative study aimed to examine how abortion clients in Nigeria perceive abortion and explore the role their beliefs and fears play in their care-seeking experiences and interactions with ...providers. Abortion is severely legally restricted in Nigeria but remains common. We conducted in-depth interviews with 25 people who obtained abortion services through three distinct models of care. We coded interview transcripts and conducted thematic analysis. Clients perceived negative attitudes toward abortion in their communities, though clients' own beliefs were more nuanced. Clients recounted a range of fears, and nearly all mentioned worrying that they might die as a result of their abortion. Despite their concerns, clients relied on social networks and word-of-mouth recommendations to identify providers they perceived as trustworthy and safe. Kind and non-judgmental treatment, clear instructions, open communication, and reassurance of privacy and confidentiality by providers alleviated client fears and helped clients feel supported throughout their abortion process. Within restrictive contexts, the mobilization of information networks, provision of high-quality care through innovative models, and personalization of care to individual needs can assuage fears and contribute to reducing stigma and increasing access to safe abortion services.
The prognosis of cholangiocarcinoma (CC) is dismal. Notch has been identified as a potential driver; forced exogenous overexpression of Notch1 in hepatocytes results in the formation of biliary ...tumors. In human disease, however, it is unknown which components of the endogenously signaling pathway are required for tumorigenesis, how these orchestrate cancer, and how they can be targeted for therapy. Here we characterize Notch in human-resected CC, a toxin-driven model in rats, and a transgenic mouse model in which p53 deletion is targeted to biliary epithelia and CC induced using the hepatocarcinogen thioacetamide. We find that across species, the atypical receptor NOTCH3 is differentially overexpressed; it is progressively up-regulated with disease development and promotes tumor cell survival via activation of PI3k-Akt. We use genetic KO studies to show that tumor growth significantly attenuates after Notch3 deletion and demonstrate signaling occurs via a noncanonical pathway independent of the mediator of classical Notch, Recombinant Signal Binding Protein for Immunoglobulin Kappa J Region (RBPJ). These data present an opportunity in this aggressive cancer to selectively target Notch, bypassing toxicities known to be RBPJ dependent.
The Cognitive Reserve (CR) hypothesis accounts for individual differences in vulnerability to age- or pathological-related brain changes. It suggests lifetime influences (e.g., education) increase ...the effectiveness of cognitive processing in later life. While evidence suggests CR proxies predict cognitive performance in older age, it is less clear whether CR proxies attenuate age-related decline on social cognitive tasks. This study investigated the effect of CR proxies on unimodal and cross-modal emotion identification. Sixty-six older adults aged 60-78 years were assessed on CR proxies (Cognitive Reserve Index Questionnaire, NART), unimodal(faces only, voices only), and cross-modal (faces and voices combined) emotion recognition and executive function (Stroop Test). No CR proxy predicted performance on emotion recognition. However, NART IQ predicted performance on the Stroop test; higher NART IQ was associated with better performance. The current study suggests CR proxies do not predict performance on social cognition tests but do predict performance on cognitive tasks.
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