| 1. |
- Locke, Adam E, et al.
(författare)
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Genetic studies of body mass index yield new insights for obesity biology.
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 518:7538, s. 197-401
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Tidskriftsartikel (refereegranskat)abstract
- Obesity is heritable and predisposes to many diseases. To understand the genetic basis of obesity better, here we conduct a genome-wide association study and Metabochip meta-analysis of body mass index (BMI), a measure commonly used to define obesity and assess adiposity, in up to 339,224 individuals. This analysis identifies 97 BMI-associated loci (P < 5 × 10(-8)), 56 of which are novel. Five loci demonstrate clear evidence of several independent association signals, and many loci have significant effects on other metabolic phenotypes. The 97 loci account for ∼2.7% of BMI variation, and genome-wide estimates suggest that common variation accounts for >20% of BMI variation. Pathway analyses provide strong support for a role of the central nervous system in obesity susceptibility and implicate new genes and pathways, including those related to synaptic function, glutamate signalling, insulin secretion/action, energy metabolism, lipid biology and adipogenesis.
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| 2. |
- Hartley, Philippa, et al.
(författare)
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SKA Science Data Challenge 2: analysis and results
- 2023
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Ingår i: Monthly Notices of the Royal Astronomical Society. - 0035-8711 .- 1365-2966. ; 523:2, s. 1967-1993
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Tidskriftsartikel (refereegranskat)abstract
- The Square Kilometre Array Observatory (SKAO) will explore the radio sky to new depths in order to conduct transformational science. SKAO data products made available to astronomers will be correspondingly large and complex, requiring the application of advanced analysis techniques to extract key science findings. To this end, SKAO is conducting a series of Science Data Challenges, each designed to familiarize the scientific community with SKAO data and to drive the development of new analysis techniques. We present the results from Science Data Challenge 2 (SDC2), which invited participants to find and characterize 233 245 neutral hydrogen (H i) sources in a simulated data product representing a 2000 h SKA-Mid spectral line observation from redshifts 0.25-0.5. Through the generous support of eight international supercomputing facilities, participants were able to undertake the Challenge using dedicated computational resources. Alongside the main challenge, 'reproducibility awards' were made in recognition of those pipelines which demonstrated Open Science best practice. The Challenge saw over 100 participants develop a range of new and existing techniques, with results that highlight the strengths of multidisciplinary and collaborative effort. The winning strategy - which combined predictions from two independent machine learning techniques to yield a 20 per cent improvement in overall performance - underscores one of the main Challenge outcomes: that of method complementarity. It is likely that the combination of methods in a so-called ensemble approach will be key to exploiting very large astronomical data sets.
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| 3. |
- Shungin, Dmitry, et al.
(författare)
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New genetic loci link adipose and insulin biology to body fat distribution.
- 2015
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 518:7538, s. 187-378
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Tidskriftsartikel (refereegranskat)abstract
- Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms.
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| 4. |
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| 5. |
- Karltun, Linley Chiwona, et al.
(författare)
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COVID-19: From health crises to food security anxiety and policy implications
- 2021
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 50, s. 794-811
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Tidskriftsartikel (refereegranskat)abstract
- Like the rest of the world, African countries are reeling from the health, economic and social effects of COVID-19. The continent's governments have responded by imposing rigorous lockdowns to limit the spread of the virus. The various lockdown measures are undermining food security, because stay at home orders have among others, threatened food production for a continent that relies heavily on agriculture as the bedrock of the economy. This article draws on quantitative data collected by the GeoPoll, and, from these data, assesses the effect of concern about the local spread and economic impact of COVID-19 on food worries. Qualitative data comprising 12 countries south of the Sahara reveal that lockdowns have created anxiety over food security as a health, economic and human rights/well-being issue. By applying a probit model, we find that concern about the local spread of COVID-19 and economic impact of the virus increases the probability of food worries. Governments have responded with various efforts to support the neediest. By evaluating the various policies rolled out we advocate for a feminist economics approach that necessitates greater use of data analytics to predict the likely impacts of intended regulatory relief responses during the recovery process and post-COVID-19.
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| 6. |
- Ried, Janina S., et al.
(författare)
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A principal component meta-analysis on multiple anthropometric traits identifies novel loci for body shape
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Large consortia have revealed hundreds of genetic loci associated with anthropometric traits, one trait at a time. We examined whether genetic variants affect body shape as a composite phenotype that is represented by a combination of anthropometric traits. We developed an approach that calculates averaged PCs (AvPCs) representing body shape derived from six anthropometric traits (body mass index, height, weight, waist and hip circumference, waist-to-hip ratio). The first four AvPCs explain >99% of the variability, are heritable, and associate with cardiometabolic outcomes. We performed genome-wide association analyses for each body shape composite phenotype across 65 studies and meta-analysed summary statistics. We identify six novel loci: LEMD2 and CD47 for AvPC1, RPS6KA5/C14orf159 and GANAB for AvPC3, and ARL15 and ANP32 for AvPC4. Our findings highlight the value of using multiple traits to define complex phenotypes for discovery, which are not captured by single-trait analyses, and may shed light onto new pathways.
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| 7. |
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| 8. |
- Ben Sedrine, N., et al.
(författare)
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Fluctuating potentials in GaAs : Si nanowires: Critical reduction of the influence of polytypism on the electronic structure
- 2018
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 10:8, s. 3697-3708
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the effects of Si doping in GaAs nanowires (NWs) grown on GaAs (111)B by molecular beam epitaxy with different Si doping levels (nominal free carrier concentrations of 1 × 1016, 8 × 1016, 1 × 1018 and 5 × 1018 cm-3) are deeply investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), grazing incidence X-ray diffraction (GID), photoluminescence (PL) and cathadoluminescence (CL). TEM results reveal a mixture of wurtzite (WZ) and zinc-blende (ZB) segments along the NW axis independently of the Si doping levels. GID measurements suggest a slight increase of the ZB fraction with the Si doping. Low temperature PL and CL spectra exhibit sharp lines in the energy range 1.41-1.48 eV, for the samples with lower Si doping levels. However, the emission intensity increases and is accompanied by a clear broadening of the observed lines for the samples with higher Si doping levels. The staggered type-II band alignment only determines the optical properties of the lower doping levels in GaAs:Si NWs. For the higher Si doping levels, the electronic energy level structure of the NWs is determined by electrostatic fluctuating potentials intimately related to the amphoteric behavior of the Si dopant in GaAs. For the heavily doped NWs, the estimated depth of the potential wells is ∼96-117 meV. Our results reveal that the occurrence of the fluctuating potentials is not dependent on the crystalline phase and shows that the limitation imposed by the polytypism can be overcome.
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| 9. |
- Byskov, Jens, et al.
(författare)
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The accountability for reasonableness approach to guide priority setting in health systems within limited resources : findings from action research at district level in Kenya, Tanzania, and Zambia
- 2014
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Ingår i: Health Research Policy and Systems. - : BioMed Central. - 1478-4505. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Priority-setting decisions are based on an important, but not sufficient set of values and thus lead to disagreement on priorities. Accountability for Reasonableness (AFR) is an ethics-based approach to a legitimate and fair priority-setting process that builds upon four conditions: relevance, publicity, appeals, and enforcement, which facilitate agreement on priority-setting decisions and gain support for their implementation. This paper focuses on the assessment of AFR within the project REsponse to ACcountable priority setting for Trust in health systems (REACT). Methods: This intervention study applied an action research methodology to assess implementation of AFR in one district in Kenya, Tanzania, and Zambia, respectively. The assessments focused on selected disease, program, and managerial areas. An implementing action research team of core health team members and supporting researchers was formed to implement, and continually assess and improve the application of the four conditions. Researchers evaluated the intervention using qualitative and quantitative data collection and analysis methods. Results: The values underlying the AFR approach were in all three districts well-aligned with general values expressed by both service providers and community representatives. There was some variation in the interpretations and actual use of the AFR in the decision-making processes in the three districts, and its effect ranged from an increase in awareness of the importance of fairness to a broadened engagement of health team members and other stakeholders in priority setting and other decision-making processes. Conclusions: District stakeholders were able to take greater charge of closing the gap between nationally set planning and the local realities and demands of the served communities within the limited resources at hand. This study thus indicates that the operationalization of the four broadly defined and linked conditions is both possible and seems to be responding to an actual demand. This provides arguments for the continued application and further assessment of the potential of AFR in supporting priority-setting and other decision-making processes in health systems to achieve better agreed and more sustainable health improvements linked to a mutual democratic learning with potential wider implications.
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| 10. |
- Cunha, Jose M., V, et al.
(författare)
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Decoupling of Optical and Electrical Properties of Rear Contact CIGS Solar Cells
- 2019
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Ingår i: IEEE Journal of Photovoltaics. - : Institute of Electrical and Electronics Engineers (IEEE). - 2156-3381 .- 2156-3403. ; 9:6, s. 1857-1862
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Tidskriftsartikel (refereegranskat)abstract
- A novel architecture that comprises rear interface passivation and increased rear optical reflection is presented with the following advantages: i) enhanced optical reflection is achieved by the deposition of a metallic layer over the Mo rear contact; ii) improved interface qualitywithCIGS by adding a sputteredAl 2O 3 layer over the metallic layer; and, iii) optimal ohmic electrical contact ensured by rear-openings refilling with a second layer of Mo as generally observed from the growth of CIGS on Mo. Hence, a decoupling between the electrical function and the optical purpose of the rear substrate is achieved. We present in detail the manufacturing procedure of such type of architecture together with its benefits and caveats. A preliminary analysis showing an architecture proof-of-concept is presented and discussed.
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| 11. |
- Karat, Aaron S., et al.
(författare)
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Measuring mortality due to HIV-associated tuberculosis among adults in South Africa : Comparing verbal autopsy, minimally-invasive autopsy, and research data
- 2017
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Background The World Health Organization (WHO) aims to reduce tuberculosis (TB) deaths by 95% by 2035; tracking progress requires accurate measurement of TB mortality. International Classification of Diseases (ICD) codes do not differentiate between HIV-associated TB and HIV more generally. Verbal autopsy (VA) is used to estimate cause of death (CoD) patterns but has mostly been validated against a suboptimal gold standard for HIV and TB. This study, conducted among HIV-positive adults, aimed to estimate the accuracy of VA in ascertaining TB and HIV CoD when compared to a reference standard derived from a variety of clinical sources including, in some, minimally-invasive autopsy (MIA). Methods and findings Decedents were enrolled into a trial of empirical TB treatment or a cohort exploring diagnostic algorithms for TB in South Africa. The WHO 2012 instrument was used; VA CoD were assigned using physician-certified VA (PCVA), InterVA-4, and SmartVA-Analyze. Reference CoD were assigned using MIA, research, and health facility data, as available. 259 VAs were completed: 147 (57%) decedents were female; median age was 39 (interquartile range [IQR] 33-47) years and CD4 count 51 (IQR 22-102) cells/mu L. Compared to reference CoD that included MIA (n = 34), VA underestimated mortality due to HIV/AIDS (94% reference, 74% PCVA, 47% InterVA-4, and 41% SmartVA-Analyze; chance-corrected concordance [CCC] 0.71, 0.42, and 0.31, respectively) and HIV-associated TB (41% reference, 32% PCVA; CCC 0.23). For individual decedents, all VA methods agreed poorly with reference CoD that did not include MIA (n = 259; overall CCC 0.14, 0.06, and 0.15 for PCVA, InterVA-4, and SmartVA-Analyze); agreement was better at population level (cause-specific mortality fraction accuracy 0.78, 0.61, and 0.57, for the three methods, respectively). Conclusions Current VA methods underestimate mortality due to HIV-associated TB. ICD and VA methods need modifications that allow for more specific evaluation of HIV-related deaths and direct estimation of mortality due to HIV-associated TB.
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| 12. |
- Karat, Aaron S., et al.
(författare)
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Performance of verbal autopsy methods in estimating HIV-associated mortality among adults in South Africa
- 2018
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Ingår i: BMJ Global Health. - : BMJ Publishing Group Ltd. - 2059-7908. ; 3:4
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Verbal autopsy (VA) can be integrated into civil registration and vital statistics systems, but its accuracy in determining HIV-associated causes of death (CoD) is uncertain. We assessed the sensitivity and specificity of VA questions in determining HIV status and antiretroviral therapy (ART) initiation and compared HIV-associated mortality fractions assigned by different VA interpretation methods.Methods: Using the WHO 2012 instrument with added ART questions, VA was conducted for deaths among adults with known HIV status (356 HIV positive and 103 HIV negative) in South Africa. CoD were assigned using physician-certified VA (PCVA) and computer-coded VA (CCVA) methods and compared with documented HIV status.Results: The sensitivity of VA questions in detecting HIV status and ART initiation was 84.3% (95% CI 80 to 88) and 91.0% (95% CI 86 to 95); 283/356 (79.5%) HIV-positive individuals were assigned HIV-associated CoD by PCVA, 166 (46.6%) by InterVA-4.03, 201 (56.5%) by InterVA-5, and 80 (22.5%) and 289 (81.2%) by SmartVA-Analyze V.1.1.1 and V.1.2.1. Agreement between PCVA and older CCVA methods was poor (chance-corrected concordance [CCC] <0; cause-specific mortality fraction [CSMF] accuracy <= 56%) but better between PCVA and updated methods (CCC 0.21-0.75; CSMF accuracy 65%-98%). All methods were specific (specificity 87% to 96%) in assigning HIV-associated CoD.Conclusion: All CCVA interpretation methods underestimated the HIV-associated mortality fraction compared with PCVA; InterVA-5 and SmartVA-Analyze V. 1.2.1 performed better than earlier versions. Changes to VA methods and classification systems are needed to track progress towards targets for reducing HIV-associated mortality.
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| 13. |
- Lopes, T. S., et al.
(författare)
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Cu(In,Ga)Se2 based ultrathin solar cells the pathway from lab rigid to large scale flexible technology
- 2023
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Ingår i: npj Flexible Electronics. - : Springer Nature. - 2397-4621. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- The incorporation of interface passivation structures in ultrathin Cu(In,Ga)Se2 based solar cells is shown. The fabrication used an industry scalable lithography technique—nanoimprint lithography (NIL)—for a 15 × 15 cm2 dielectric layer patterning. Devices with a NIL nanopatterned dielectric layer are benchmarked against electron-beam lithography (EBL) patterning, using rigid substrates. The NIL patterned device shows similar performance to the EBL patterned device.The impact of the lithographic processes in the rigid solar cells’ performance were evaluated via X-ray Photoelectron Spectroscopy and through a Solar Cell Capacitance Simulator. The device on stainless-steel showed a slightly lower performance than the rigid approach, due to additional challenges of processing steel substrates, even though scanning transmission electron microscopy did not show clear evidence of impurity diffusion. Notwithstanding, time-resolved photoluminescence results strongly suggested elemental diffusion from the flexible substrate. Nevertheless, bending tests on the stainless-steel device demonstrated the mechanical stability of the CIGS-based device.
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| 14. |
- Maro, Salome, 1987, et al.
(författare)
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Managing Traceability Information Models: Not Such a Simple Task After All?
- 2021
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Ingår i: IEEE Software. - 0740-7459 .- 1937-4194. ; 38:5
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Tidskriftsartikel (refereegranskat)abstract
- Practitioners are poorly supported by the scientific literature when managing traceability information models (TIMs), which capture the structure and semantics of trace links. In practice, companies manage their TIMs in very different ways, even in cases where companies share many similarities. We present our findings from an in-depth focus group about TIM management with three different systems engineering companies. We find that the concrete needs of the companies as well as challenges such as scale and workflow integration are not considered by existing scientific work. We thus issue a call-to-arms for the requirements engineering and software and systems traceability communities, the two main communities for traceability research, to refocus their work on these practical problems. IEEE
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| 15. |
- Monteiro, Margarida, et al.
(författare)
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X-ray Photoelectron Spectroscopy for Studying Passivation Architectures of Cu(In,Ga)Se-2 Cells
- 2021
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Ingår i: 2021 IEEE 48th Photovoltaic Specialists Conference (PVSC). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781665419222 ; , s. 890-892
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Konferensbidrag (refereegranskat)abstract
- Optoelectronic devices are susceptible to interface recombination, which can have a detrimental impact on their performance. Therefore, there is an urgent need for tailored passivation strategies to reach a technological boost. In this contribution, two architectures based on passivated Cu(In, Ga)Se-2 solar cells are analyzed with X-ray photoelectron spectroscopy (XPS): one based on rear passivation with gold nanoparticle aggregates, and the other with Al2O3 as a front passivation layer. It is demonstrated that XPS can assist in the understanding of passivated devices from a chemical point of view, comprehend their limitations and push forward the development of future devices.
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| 16. |
- Oliveira, Kevin, et al.
(författare)
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SiO$_x$ Patterned Based Substrates Implemented in Cu(In,Ga)Se$_2$ Ultrathin Solar Cells : Optimum Thickness
- 2022
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Ingår i: IEEE Journal of Photovoltaics. - : Institute of Electrical and Electronics Engineers (IEEE). - 2156-3381 .- 2156-3403. ; 12:4, s. 954-961
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Tidskriftsartikel (refereegranskat)abstract
- Interface recombination in sub-mu m optoelectronics has a major detrimental impact on devices' performance, showing the need for tailored passivation strategies to reach a technological boost. In this article, SiO$_x$ passivation based substrates were developed and integrated into ultrathin Cu(In,Ga)Se$_2$ (CIGS) solar cells. This article aims to understand the impact of a passivation strategy, which uses several SiO$_x$ layer thicknesses (3, 8, and 25 nm) integrated into high-performance substrates (HPS). The experimental study is complemented with 3-D lumerical finite-difference time-domain and 2-D Silvaco ATLAS optical and electrical simulations, respectively, to perform a decoupling of optical and electronic gains, allowing for a deep discussion on the impact of the SiO$_x$ layer thickness in the CIGS solar cell performance. This article shows that as the passivation layer thickness increases, a rise in parasitic losses is observed. Hence, a balance between beneficial passivation and optical effects with harmful architectural constraints defines a threshold thickness to attain the best solar cell performance. Analyzing their electrical parameters, the 8-nm novel SiO$_x$ based substrate achieved a light to power conversion efficiency value of 13.2%, a 1.3% absolute improvement over the conventional Mo substrate (without SiO$_x$).
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| 17. |
- Oliveira, Kevin, et al.
(författare)
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SiOx patterned based substrates implemented in Cu(In,Ga)Se-2 ultrathin solar cells : optimum thickness
- 2021
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Ingår i: 2021 IEEE 48th Photovoltaic Specialists Conference (PVSC). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781665419222 ; , s. 928-930
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Konferensbidrag (refereegranskat)abstract
- Interface recombination in sub-mu m optoelectronic devices has a major harmful impact in devices performance, showing the need for tailored passivation strategies in order to reach a technological boost. In this work, SiOx based substrates were developed and integrated in ultrathin CIGS solar cells. This study aims at understanding the impact of several SiOx layer thicknesses (3, 8 and 25 nm) when this material is used as a passivation layer. Analysing their electrical parameters, the 8 nm novel SiOx based substrates achieved light to power conversion efficiency values up to 13.2 %, a 1.3 % absolute improvement over the conventional substrate (without SiOx).
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| 18. |
- Ruggeri, Kai, et al.
(författare)
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The general fault in our fault lines
- 2021
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Ingår i: Nature Human Behaviour. - : Springer Nature. - 2397-3374. ; 5:10, s. 1369-1380
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Tidskriftsartikel (refereegranskat)abstract
- Pervading global narratives suggest that political polarization is increasing, yet the accuracy of such group meta-perceptions has been drawn into question. A recent US study suggests that these beliefs are inaccurate and drive polarized beliefs about out-groups. However, it also found that informing people of inaccuracies reduces those negative beliefs. In this work, we explore whether these results generalize to other countries. To achieve this, we replicate two of the original experiments with 10,207 participants across 26 countries. We focus on local group divisions, which we refer to as fault lines. We find broad generalizability for both inaccurate meta-perceptions and reduced negative motive attribution through a simple disclosure intervention. We conclude that inaccurate and negative group meta-perceptions are exhibited in myriad contexts and that informing individuals of their misperceptions can yield positive benefits for intergroup relations. Such generalizability highlights a robust phenomenon with implications for political discourse worldwide.
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| 19. |
- Salome, P. M. P., et al.
(författare)
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CdS and Zn1-xSnxOy buffer layers for CIGS solar cells
- 2017
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Ingår i: Solar Energy Materials and Solar Cells. - : Elsevier BV. - 0927-0248 .- 1879-3398. ; 159, s. 272-281
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Tidskriftsartikel (refereegranskat)abstract
- Thin film solar cells based on Cu(In,Ga)Se-2 (CIGS), where just the buffer layer is changed, were fabricated and studied. The effects of two different buffer layers, CdS and Zn1-xSnxOy (ZnSnO), are compared using several characterization techniques. We compared both devices and observe that the ZnSnO-based solar cells have similar values of power conversion efficiency as compared to the cells with CdS buffer layers. The ZnSnO-based devices have higher values in the short-circuit current (6) that compensate for lower values in fill factor (FF) and open circuit voltage (V-oc) than CdS based devices. Kelvin probe force microscopy (KPFM) results indicate that CdS provides junctions with slightly higher surface photovoltage (SPV) than ZnSnO, thus explaining the lower Voc potential for the ZnSnO sample. The TEM analysis shows a poly-crystalline ZnSnO layer and we have not detected any strong evidence of diffusion of Zn or Sn into the CIGS. From the photoluminescence measurements, we concluded that both samples are being affected by fluctuating potentials, although this effect is higher for the CdS sample.
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| 20. |
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