Showing papers by "National Technical University of Athens published in 2020"
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23 Feb 2020
TL;DR: The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper, where a brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.
Abstract: The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.
3,111 citations
TL;DR: All aspects of M4 are covered in detail, including its organization and running, the presentation of its results, the top-performing methods overall and by categories, its major findings and their implications, and the computational requirements of the various methods.
507 citations
University of Waterloo1, National Technical University of Athens2, University of Alaska Fairbanks3, École Polytechnique Fédérale de Lausanne4, University of Kiel5, RMIT University6, University of St. Thomas (Minnesota)7, Nanyang Technological University8, Pacific Northwest National Laboratory9, Microsoft10, University of South Florida11, University of Chile12, South Dakota State University13
TL;DR: In this paper, definitions and classification of microgrid stability are presented and discussed, considering pertinent microgrid features such as voltage-frequency dependence, unbalancing, low inertia, and generation intermittency.
Abstract: This document is a summary of a report prepared by the IEEE PES Task Force (TF) on Microgrid Stability Definitions, Analysis, and Modeling, IEEE Power and Energy Society, Piscataway, NJ, USA, Tech. Rep. PES-TR66, Apr. 2018, which defines concepts and identifies relevant issues related to stability in microgrids. In this paper, definitions and classification of microgrid stability are presented and discussed, considering pertinent microgrid features such as voltage-frequency dependence, unbalancing, low inertia, and generation intermittency. A few examples are also presented, highlighting some of the stability classes defined in this paper. Further examples, along with discussions on microgrid components modeling and stability analysis tools can be found in the TF report.
403 citations
TL;DR: In this paper, a self-assembled monolayer (SAM) 2PACz was used as a hole-selective interlayer functionalized directly onto the indium tin oxid.
Abstract: We report on bulk-heterojunction (BHJ) organic photovoltaics (OPVs) based on the self-assembled monolayer (SAM) 2PACz as a hole-selective interlayer functionalized directly onto the indium tin oxid
367 citations
TL;DR: In this article, a search for the electroweak production of charginos and sleptons decaying into final states with two electrons or muons is presented, based on 139.fb$^{-1}$ of proton-proton collisions recorded by the ATLAS detector at the Large Hadron Collider at
Abstract: A search for the electroweak production of charginos and sleptons decaying into final states with two electrons or muons is presented. The analysis is based on 139 fb$^{-1}$ of proton–proton collisions recorded by the ATLAS detector at the Large Hadron Collider at $\sqrt{s}=13$ $\text {TeV}$. Three R-parity-conserving scenarios where the lightest neutralino is the lightest supersymmetric particle are considered: the production of chargino pairs with decays via either W bosons or sleptons, and the direct production of slepton pairs. The analysis is optimised for the first of these scenarios, but the results are also interpreted in the others. No significant deviations from the Standard Model expectations are observed and limits at 95% confidence level are set on the masses of relevant supersymmetric particles in each of the scenarios. For a massless lightest neutralino, masses up to 420 $\text {Ge}\text {V}$ are excluded for the production of the lightest-chargino pairs assuming W-boson-mediated decays and up to 1 $\text {TeV}$ for slepton-mediated decays, whereas for slepton-pair production masses up to 700 $\text {Ge}\text {V}$ are excluded assuming three generations of mass-degenerate sleptons.
272 citations
University of Duisburg-Essen1, University of Stirling2, Aarhus University3, Middle East Technical University4, University of Lisbon5, Laval University6, Norwegian Institute for Water Research7, Estonian University of Life Sciences8, Lancaster University9, Leibniz Association10, Technical University of Berlin11, University of Ljubljana12, Helmholtz Centre for Environmental Research - UFZ13, University of Natural Resources and Life Sciences, Vienna14, Cardiff University15, University of Barcelona16, Finnish Environment Institute17, DHI Water & Environment18, National Technical University of Athens19, Radboud University Nijmegen20, Free University of Berlin21, University of Koblenz and Landau22
TL;DR: A cross-scale analysis of paired-stressor effects on biological variables of European freshwater ecosystems shows that in 39% of cases, significant effects were limited to single stressors, with nutrient enrichment being the most important of these in lakes.
Abstract: Climate and land-use change drive a suite of stressors that shape ecosystems and interact to yield complex ecological responses (that is, additive, antagonistic and synergistic effects). We know little about the spatial scales relevant for the outcomes of such interactions and little about effect sizes. These knowledge gaps need to be filled to underpin future land management decisions or climate mitigation interventions for protecting and restoring freshwater ecosystems. This study combines data across scales from 33 mesocosm experiments with those from 14 river basins and 22 cross-basin studies in Europe, producing 174 combinations of paired-stressor effects on a biological response variable. Generalized linear models showed that only one of the two stressors had a significant effect in 39% of the analysed cases, 28% of the paired-stressor combinations resulted in additive effects and 33% resulted in interactive (antagonistic, synergistic, opposing or reversal) effects. For lakes, the frequencies of additive and interactive effects were similar for all spatial scales addressed, while for rivers these frequencies increased with scale. Nutrient enrichment was the overriding stressor for lakes, with effects generally exceeding those of secondary stressors. For rivers, the effects of nutrient enrichment were dependent on the specific stressor combination and biological response variable. These results vindicate the traditional focus of lake restoration and management on nutrient stress, while highlighting that river management requires more bespoke management solutions.
267 citations
TL;DR: For the first time, predictions from pythia8 obtained with tunes based on NLO or NNLO PDFs are shown to reliably describe minimum-bias and underlying-event data with a similar level of agreement to predictions from tunes using LO PDF sets.
Abstract: New sets of CMS underlying-event parameters (“tunes”) are presented for the pythia8 event generator. These tunes use the NNPDF3.1 parton distribution functions (PDFs) at leading (LO), next-to-leading (NLO), or next-to-next-to-leading (NNLO) orders in perturbative quantum chromodynamics, and the strong coupling evolution at LO or NLO. Measurements of charged-particle multiplicity and transverse momentum densities at various hadron collision energies are fit simultaneously to determine the parameters of the tunes. Comparisons of the predictions of the new tunes are provided for observables sensitive to the event shapes at LEP, global underlying event, soft multiparton interactions, and double-parton scattering contributions. In addition, comparisons are made for observables measured in various specific processes, such as multijet, Drell–Yan, and top quark-antiquark pair production including jet substructure observables. The simulation of the underlying event provided by the new tunes is interfaced to a higher-order matrix-element calculation. For the first time, predictions from pythia8 obtained with tunes based on NLO or NNLO PDFs are shown to reliably describe minimum-bias and underlying-event data with a similar level of agreement to predictions from tunes using LO PDF sets.
265 citations
TL;DR: In this article, neutral Diquat (DQ) was used as n-dopant to improve the operating characteristics of organic photovoltaics (OPVs).
Abstract: Molecular doping has recently been shown to improve the operating characteristics of organic photovoltaics (OPVs). Here, we prepare neutral Diquat (DQ) and use it as n-dopant to improve the perform...
239 citations
TL;DR: In order to effectively implement technologies based on biological resources, it is necessary to construct small wastes solubilization or fertilizer installations at the site of waste generation, which will solve the problem of waste transport or sanitary hazards.
217 citations
Utrecht University1, Netherlands Environmental Assessment Agency2, Potsdam Institute for Climate Impact Research3, Wageningen University and Research Centre4, International Institute for Applied Systems Analysis5, Technical University of Berlin6, European Institute7, Kyoto University8, National Technical University of Athens9, Imperial College London10, Federal University of Rio de Janeiro11, Tsinghua University12, Joint Global Change Research Institute13, National Development and Reform Commission14, The Energy and Resources Institute15, National Research University – Higher School of Economics16, National Institute for Environmental Studies17, Indian Institute of Management Ahmedabad18
TL;DR: It is shown that implementation of current policies leaves a median emission gap of 22.4 to 28.2 GtCO 2 eq by 2030 with the optimal pathways to implement the well below 2 °C and 1.5C Paris goals, which shows that all countries would need to accelerate the implementation of policies for renewable technologies, while efficiency improvements are especially important in emerging countries and fossil-fuel-dependent countries.
Abstract: Many countries have implemented national climate policies to accomplish pledged Nationally Determined Contributions and to contribute to the temperature objectives of the Paris Agreement on climate change. In 2023, the global stocktake will assess the combined effort of countries. Here, based on a public policy database and a multi-model scenario analysis, we show that implementation of current policies leaves a median emission gap of 22.4 to 28.2 GtCO2eq by 2030 with the optimal pathways to implement the well below 2 °C and 1.5 °C Paris goals. If Nationally Determined Contributions would be fully implemented, this gap would be reduced by a third. Interestingly, the countries evaluated were found to not achieve their pledged contributions with implemented policies (implementation gap), or to have an ambition gap with optimal pathways towards well below 2 °C. This shows that all countries would need to accelerate the implementation of policies for renewable technologies, while efficiency improvements are especially important in emerging countries and fossil-fuel-dependent countries.
201 citations
TL;DR: The thrust of this review is to outline emerging applications of DL and provide a reference to researchers seeking to use DL in their work for pattern recognition with unparalleled learning capacity and the ability to scale with data.
Abstract: Deep learning (DL) has solved a problem that a few years ago was thought to be intractable — the automatic recognition of patterns in spatial and temporal data with an accuracy superior to that of humans. It has solved problems beyond the realm of traditional, hand-crafted machine learning algorithms and captured the imagination of practitioners who are inundated with all types of data. As public awareness of the efficacy of DL increases so does the desire to make use of it. But even for highly trained professionals it can be daunting to approach the rapidly increasing body of knowledge in the field. Where does one start? How does one determine if a particular DL model is applicable to their problem? How does one train and deploy them? With these questions in mind, we present an overview of some of the key DL architectures. We also discuss some new automatic architecture optimization protocols that use multi-agent approaches. Further, since guaranteeing system uptime is critical to many applications, a section dwells on using DL for fault detection and mitigation. This is followed by an exploratory survey of several areas where DL emerged as a game-changer: fraud detection in financial applications, financial time-series forecasting, predictive and prescriptive analytics, medical image processing, power systems research and recommender systems. The thrust of this review is to outline emerging applications of DL and provide a reference to researchers seeking to use DL in their work for pattern recognition with unparalleled learning capacity and the ability to scale with data.
TL;DR: In this paper, the trigger algorithms and selection were optimized to control the rates while retaining a high efficiency for physics analyses at the ATLAS experiment to cope with a fourfold increase of peak LHC luminosity from 2015 to 2018 (Run 2), and a similar increase in the number of interactions per beam-crossing to about 60.
Abstract: Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for the ATLAS experiment to record signals for a wide variety of physics: from Standard Model processes to searches for new phenomena in both proton–proton and heavy-ion collisions. To cope with a fourfold increase of peak LHC luminosity from 2015 to 2018 (Run 2), to 2.1×1034cm-2s-1, and a similar increase in the number of interactions per beam-crossing to about 60, trigger algorithms and selections were optimised to control the rates while retaining a high efficiency for physics analyses. For proton–proton collisions, the single-electron trigger efficiency relative to a single-electron offline selection is at least 75% for an offline electron of 31 GeV, and rises to 96% at 60 GeV; the trigger efficiency of a 25 GeV leg of the primary diphoton trigger relative to a tight offline photon selection is more than 96% for an offline photon of 30 GeV. For heavy-ion collisions, the primary electron and photon trigger efficiencies relative to the corresponding standard offline selections are at least 84% and 95%, respectively, at 5 GeV above the corresponding trigger threshold.
TL;DR: A search for heavy neutral Higgs bosons is performed using the LHC Run 2 data, corresponding to an integrated luminosity of 139 fb^{-1} of proton-proton collisions at sqrt[s]=13TeV recorded with the ATLAS detector.
Abstract: A search for heavy neutral Higgs bosons is performed using the LHC Run 2 data, corresponding to an integrated luminosity of 139 fb^{-1} of proton-proton collisions at sqrt[s]=13 TeV recorded with the ATLAS detector. The search for heavy resonances is performed over the mass range 0.2-2.5 TeV for the τ^{+}τ^{-} decay with at least one τ-lepton decaying into final states with hadrons. The data are in good agreement with the background prediction of the standard model. In the M_{h}^{125} scenario of the minimal supersymmetric standard model, values of tanβ>8 and tanβ>21 are excluded at the 95% confidence level for neutral Higgs boson masses of 1.0 and 1.5 TeV, respectively, where tanβ is the ratio of the vacuum expectation values of the two Higgs doublets.
University of Cyprus1, University of Louisville2, University of Kragujevac3, Emory University4, University of Edinburgh5, University of Auckland6, Rutgers University7, United States Department of Veterans Affairs8, National and Kapodistrian University of Athens9, Stony Brook University10, Regenstrief Institute11, National Technical University of Athens12, Technical University of Crete13
TL;DR: Integrative analytics approaches driven by associate research branches highlighted in this study promise to revolutionize imaging informatics as known today across the healthcare continuum for both radiology and digital pathology applications.
Abstract: This paper reviews state-of-the-art research solutions across the spectrum of medical imaging informatics, discusses clinical translation, and provides future directions for advancing clinical practice. More specifically, it summarizes advances in medical imaging acquisition technologies for different modalities, highlighting the necessity for efficient medical data management strategies in the context of AI in big healthcare data analytics. It then provides a synopsis of contemporary and emerging algorithmic methods for disease classification and organ/ tissue segmentation, focusing on AI and deep learning architectures that have already become the de facto approach. The clinical benefits of in-silico modelling advances linked with evolving 3D reconstruction and visualization applications are further documented. Concluding, integrative analytics approaches driven by associate research branches highlighted in this study promise to revolutionize imaging informatics as known today across the healthcare continuum for both radiology and digital pathology applications. The latter, is projected to enable informed, more accurate diagnosis, timely prognosis, and effective treatment planning, underpinning precision medicine.
TL;DR: The effectiveness of the n‐doping strategy highlights electron transport in NFA‐based OPVs as being a key issue and results in balanced hole and electron mobilities, higher absorption coefficients and increased charge‐carrier density within the BHJ, while significantly extending the cells' shelf‐lifetime.
Abstract: Molecular doping is often used in organic semiconductors to tune their (opto)electronic properties. Despite its versatility, however, its application in organic photovoltaics (OPVs) remains limited and restricted to p-type dopants. In an effort to control the charge transport within the bulk-heterojunction (BHJ) of OPVs, the n-type dopant benzyl viologen (BV) is incorporated in a BHJ composed of the donor polymer PM6 and the small-molecule acceptor IT-4F. The power conversion efficiency (PCE) of the cells is found to increase from 13.2% to 14.4% upon addition of 0.004 wt% BV. Analysis of the photoactive materials and devices reveals that BV acts simultaneously as n-type dopant and microstructure modifier for the BHJ. Under optimal BV concentrations, these synergistic effects result in balanced hole and electron mobilities, higher absorption coefficients and increased charge-carrier density within the BHJ, while significantly extending the cells' shelf-lifetime. The n-type doping strategy is applied to five additional BHJ systems, for which similarly remarkable performance improvements are obtained. OPVs of particular interest are based on the ternary PM6:Y6:PC71BM:BV(0.004 wt%) blend for which a maximum PCE of 17.1%, is obtained. The effectiveness of the n-doping strategy highlights electron transport in NFA-based OPVs as being a key issue.
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Polytechnic University of Turin1, National Technical University of Athens2, KEDGE Business School3, University of Birmingham4, University of Mons5, Monash University6, University of Southampton7, Lancaster University8, University of Glasgow9, University of Brescia10, University of Oxford11, Zürcher Fachhochschule12, University of Reading13, University of Lisbon14, University of the Algarve15, Pontifical Catholic University of Rio de Janeiro16, Ghent University17, Nicolaus Copernicus University in Toruń18, Erasmus University Rotterdam19, SAS Institute20, University of Bath21, University of Padua22, University of Virginia23, Bocconi University24, MODUL University Vienna25, University of Maryland, College Park26, University College London27, Amazon.com28, KAIST29, Georgetown University30, Beihang University31, Miami University32, University of Skövde33, Central University of Finance and Economics34, Manchester Metropolitan University35, University of Nicosia36, United States Department of the Treasury37, George Washington University38, Durham University39, University College Dublin40, Australian National University41, University of Sydney42, University of Thessaly43, University of Valencia44, University of Bristol45, University of Castilla–La Mancha46, Technical University of Denmark47, Polytechnic Institute of Porto48, Saint Louis University49, Cardiff University50, Warsaw School of Economics51, Macquarie University52, University of Moratuwa53, University of Sri Jayewardenepura54, International Institute of Minnesota55, National and Kapodistrian University of Athens56, Norwegian Computing Center57, University of Bologna58, Duke University59, University of Duisburg-Essen60
TL;DR: A non-systematic review of the theory and the practice of forecasting, offering a wide range of theoretical, state-of-the-art models, methods, principles, and approaches to prepare, produce, organise, and evaluate forecasts.
Abstract: Forecasting has always been at the forefront of decision making and planning. The uncertainty that surrounds the future is both exciting and challenging, with individuals and organisations seeking to minimise risks and maximise utilities. The large number of forecasting applications calls for a diverse set of forecasting methods to tackle real-life challenges. This article provides a non-systematic review of the theory and the practice of forecasting. We provide an overview of a wide range of theoretical, state-of-the-art models, methods, principles, and approaches to prepare, produce, organise, and evaluate forecasts. We then demonstrate how such theoretical concepts are applied in a variety of real-life contexts.
We do not claim that this review is an exhaustive list of methods and applications. However, we wish that our encyclopedic presentation will offer a point of reference for the rich work that has been undertaken over the last decades, with some key insights for the future of forecasting theory and practice. Given its encyclopedic nature, the intended mode of reading is non-linear. We offer cross-references to allow the readers to navigate through the various topics. We complement the theoretical concepts and applications covered by large lists of free or open-source software implementations and publicly-available databases.
TL;DR: The purpose of this review is to analyze the potential impacts of desalination and brine treatment on the environment and suggest mitigation measures.
TL;DR: In this paper, a case-study is presented under two different scenarios, Scenario 1 (MLD system) and Scenario 2 (ZLD system), where the authors showed that the energy consumption of the ZLD system is 10.43 kW h/m3 which is 1.93 times higher than that of the MLD system.
Abstract: Brine is a saline wastewater generated from several industries (e.g., desalination, energy and oil production) and its disposal can have adverse environmental impacts. To address this issue, brine treatment seems to be a promising option to eliminate the wastewater discharge, while also recovering extra freshwater and valuable materials such as salts. This can be achieved through minimal liquid discharge (MLD) and zero liquid discharge (ZLD) strategies. In this work, MLD and ZLD frameworks are analyzed and evaluated under 9 criteria (framework stages, technologies, freshwater recovery target, feed brine salinity, energy consumption of each technology, GHGs emissions, cost impact, resource recovery and social impact). Moreover, a case-study is presented under two different scenarios, Scenario 1 (MLD system) and Scenario 2 (ZLD system). Results showed that the energy consumption of the ZLD system is 10.43 kW h/m3 which is 1.93 times higher than the energy consumption of the MLD system (5.4 kW h/m3). The total freshwater recovery of the MLD system is 84.6 %, whereas the total freshwater recovery of the ZLD system is 98.15 %. Overall, the results suggest that the MLD and ZLD strategies can be valuable strategies for wastewater utilization, reuse, and resource recovery.
Aix-Marseille University1, University of Oklahoma2, University of Massachusetts Amherst3, University of Pavia4, University of Göttingen5, Royal Holloway, University of London6, University of Toronto7, Niels Bohr Institute8, University of Sussex9, Tel Aviv University10, Technion – Israel Institute of Technology11, Argonne National Laboratory12, King's College London13, International Centre for Theoretical Physics14, University of Tokyo15, University of Mainz16, University of Savoy17, AGH University of Science and Technology18, Northern Illinois University19, Ludwig Maximilian University of Munich20, Boğaziçi University21, University of Geneva22, Rutherford Appleton Laboratory23, Santa Cruz Institute for Particle Physics24, Université Paris-Saclay25, University of Auvergne26, Radboud University Nijmegen27, Alexandru Ioan Cuza University28, Spanish National Research Council29, University of Granada30, Joint Institute for Nuclear Research31, McGill University32, Lawrence Berkeley National Laboratory33, University of Rome Tor Vergata34, Kyoto University35, Russian Academy of Sciences36, University of Bologna37, University of Victoria38, CERN39, National Technical University of Athens40, University of Amsterdam41, Czech Technical University in Prague42, Tomsk State University43, University of Washington44, University of Oregon45, University of Birmingham46, University of Copenhagen47, National University of La Plata48, University of Glasgow49, Autonomous University of Madrid50, Federal University of Rio de Janeiro51, University of Oxford52, Brandeis University53, University of Michigan54, Iowa State University55, University of Sheffield56, University of Texas at Austin57, Heidelberg University58, University of Bern59, University of Milan60, Columbia University61, Novosibirsk State University62, Budker Institute of Nuclear Physics63, Oklahoma State University–Stillwater64, University of California, Irvine65, KEK66, Chinese Academy of Sciences67
TL;DR: In this article, a search for new resonances decaying into a pair of jets is reported using the dataset of proton-proton collisions recorded at s = 13 TeV with the ATLAS detector at the Large Hadron Collider between 2015 and 2018.
Abstract: A search for new resonances decaying into a pair of jets is reported using the dataset of proton-proton collisions recorded at s = 13 TeV with the ATLAS detector at the Large Hadron Collider between 2015 and 2018, corresponding to an integrated luminosity of 139 fb−1. The distribution of the invariant mass of the two leading jets is examined for local excesses above a data-derived estimate of the Standard Model background. In addition to an inclusive dijet search, events with jets identified as containing b-hadrons are examined specifically. No significant excess of events above the smoothly falling background spectra is observed. The results are used to set cross-section upper limits at 95% confidence level on a range of new physics scenarios. Model-independent limits on Gaussian-shaped signals are also reported. The analysis looking at jets containing b-hadrons benefits from improvements in the jet flavour identification at high transverse momentum, which increases its sensitivity relative to the previous analysis beyond that expected from the higher integrated luminosity.
Netherlands Environmental Assessment Agency1, Utrecht University2, Tsinghua University3, European Institute4, National Institute for Environmental Studies5, Kyoto University6, Wageningen University and Research Centre7, Federal University of Rio de Janeiro8, Imperial College London9, International Institute for Applied Systems Analysis10, Electric Power Research Institute11, The Energy and Resources Institute12, Indian Institute of Management Ahmedabad13, National Technical University of Athens14, Delft University of Technology15
TL;DR: In this article, the authors analyzed how country-level emission targets and carbon budgets can be derived based on such criteria and showed that effort-sharing approaches that (i) calculate required reduction targets in carbon budgets (relative to baseline budgets) and/or (ii) take into account historical emissions when determining carbon budget can lead to (large) negative remaining carbon budgets for developed countries.
Abstract: The bottom-up approach of the Nationally Determined Contributions (NDCs) in the Paris Agreement has led countries to self-determine their greenhouse gas (GHG) emission reduction targets. The planned ‘ratcheting-up’ process, which aims to ensure that the NDCs comply with the overall goal of limiting global average temperature increase to well below 2 °C or even 1.5 °C, will most likely include some evaluation of ‘fairness’ of these reduction targets. In the literature, fairness has been discussed around equity principles, for which many different effort-sharing approaches have been proposed. In this research, we analysed how country-level emission targets and carbon budgets can be derived based on such criteria. We apply novel methods directly based on the global carbon budget, and, for comparison, more commonly used methods using GHG mitigation pathways. For both, we studied the following approaches: equal cumulative per capita emissions, contraction and convergence, grandfathering, greenhouse development rights and ability to pay. As the results critically depend on parameter settings, we used the wide authorship from a range of countries included in this paper to determine default settings and sensitivity analyses. Results show that effort-sharing approaches that (i) calculate required reduction targets in carbon budgets (relative to baseline budgets) and/or (ii) take into account historical emissions when determining carbon budgets can lead to (large) negative remaining carbon budgets for developed countries. This is the case for the equal cumulative per capita approach and especially the greenhouse development rights approach. Furthermore, for developed countries, all effort-sharing approaches except grandfathering lead to more stringent budgets than cost-optimal budgets, indicating that cost-optimal approaches do not lead to outcomes that can be regarded as fair according to most effort-sharing approaches.
TL;DR: Current achievements in the field of fertilizers with controlled release of microelements, which, apart from the main fertilizer components, are also very significant for proper plant growth, are presented.
TL;DR: In this article, high-quality CsPbI3 films are grown via introducing a low concentration of the multifunctional molecular additive Zn(C6 F5 )2, which reconciles the conflict between air-flow-assisted fast drying and low-quality film including energy misalignment and trap formation.
Abstract: All-inorganic CsPbI3 holds promise for efficient tandem solar cells, but reported fabrication techniques are not transferrable to scalable manufacturing methods. Herein, printable CsPbI3 solar cells are reported, in which the charge transporting layers and photoactive layer are deposited by fast blade-coating at a low temperature (≤100 °C) in ambient conditions. High-quality CsPbI3 films are grown via introducing a low concentration of the multifunctional molecular additive Zn(C6 F5 )2 , which reconciles the conflict between air-flow-assisted fast drying and low-quality film including energy misalignment and trap formation. Material analysis reveals a preferential accumulation of the additive close to the perovskite/SnO2 interface and strong chemisorption on the perovskite surface, which leads to the formation of energy gradients and suppressed trap formation within the perovskite film, as well as a 150 meV improvement of the energetic alignment at the perovskite/SnO2 interface. The combined benefits translate into significant enhancement of the power conversion efficiency to 19% for printable solar cells. The devices without encapsulation degrade only by ≈2% after 700 h in air conditions.
01 Aug 2020
TL;DR: It was shown that reduced traffic volumes due to lockdown, led to a slight increase in speeds by 6–11%, but more importantly to more frequent harsh acceleration and harsh braking events during March and April 2020, which were the months where COVID-19 spread was at its peak.
Abstract: The spread of the new coronavirus COVID-19, has led to unparalleled global measures such as lockdown and suspension of all retail, recreation and religious activities during the first months of 2020. Nevertheless, no scientific evidence has been reported so far with regards to the impact on road safety and driving behavior. This paper investigates the effect of COVID-19 on driving behavior and safety indicators captured through a specially developed smartphone application and transmitted to a back-end platform. These indicators are reflected with the spread of COVID-19 and the respective governmental countermeasures in two countries, namely Greece and Kingdom of Saudi Arabia (KSA), which had the most completed routes for users of the smartphone applications. It was shown that reduced traffic volumes due to lockdown, led to a slight increase in speeds by 6-11%, but more importantly to more frequent harsh acceleration and harsh braking events (up to 12% increase) as well mobile phone use (up to 42% increase) during March and April 2020, which were the months where COVID-19 spread was at its peak. On the bright side, accidents in Greece were reduced by 41% during the first month of COVID-19-induced measures and driving in the early morning hours (00:00-05:00) which are considered dangerous dropped by up to 81%. Policymakers should concentrate on establishing new speed limits and ensure larger spaces for cycling and pedestrians in order to enlarge distances between users in order to safeguard both an enhanced level of road safety and the prevention of COVID-19 spread.
TL;DR: In this article, a measurement of the mass of the Higgs boson in the diphoton decay channel is presented, based on 35.9 fb − 1 of proton-proton collision data collected during the 2016 LHC running period, with the CMS detector at a centre-of-mass energy of 13TeV.
TL;DR: The concepts of narrow versus broad band signals are first recalled along with the limitation of the meaning of apparent power, power factor and reactive power, and the adequacy of the phasor representation of voltages and currents waveforms are discussed.
University of Nottingham1, University of Birmingham2, University of Malta3, University College Dublin4, University of Copenhagen5, Zhejiang Gongshang University6, University of Sydney7, Cornell University8, Cranfield University9, University of Santiago de Compostela10, Commonwealth Scientific and Industrial Research Organisation11, Centre national de la recherche scientifique12, University of Guelph13, Leibniz Association14, National Technical University of Athens15, Research Institutes of Sweden16, Katholieke Universiteit Leuven17
TL;DR: Graphical abstract Image 1 : as discussed by the authors ) is an example of the work presented in this paper, which is based on the work of as discussed by the authors... ]]..
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TL;DR: It is demonstrated that capillary-enwrapping projections of junctional, contractile pericytes within a postarteriole transitional region differentially constrict to structurally and dynamically determine the morphology of capillary junctions and thereby regulate branch-specific blood flow.
Abstract: The essential function of the circulatory system is to continuously and efficiently supply the O2 and nutrients necessary to meet the metabolic demands of every cell in the body, a function in which vast capillary networks play a key role. Capillary networks serve an additional important function in the central nervous system: acting as a sensory network, they detect neuronal activity in the form of elevated extracellular K+ and initiate a retrograde, propagating, hyperpolarizing signal that dilates upstream arterioles to rapidly increase local blood flow. Yet, little is known about how blood entering this network is distributed on a branch-to-branch basis to reach specific neurons in need. Here, we demonstrate that capillary-enwrapping projections of junctional, contractile pericytes within a postarteriole transitional region differentially constrict to structurally and dynamically determine the morphology of capillary junctions and thereby regulate branch-specific blood flow. We further found that these contractile pericytes are capable of receiving propagating K+-induced hyperpolarizing signals propagating through the capillary network and dynamically channeling red blood cells toward the initiating signal. By controlling blood flow at junctions, contractile pericytes within a functionally distinct postarteriole transitional region maintain the efficiency and effectiveness of the capillary network, enabling optimal perfusion of the brain.
TL;DR: In this article, the authors formulate Barrow holographic dark energy, by applying the usual holographic principle at a cosmological framework, but using the Barrow entropy instead of the standard Bekenstein-Hawking one.
Abstract: We formulate Barrow holographic dark energy, by applying the usual holographic principle at a cosmological framework, but using the Barrow entropy instead of the standard Bekenstein-Hawking one. The former is an extended black-hole entropy that arises due to quantum-gravitational effects which deform the black-hole surface by giving it an intricate, fractal form. We extract a simple differential equation for the evolution of the dark energy density parameter, which possesses standard holographic dark energy as a limiting sub-case, and we show that the scenario can describe the universe thermal history, with the sequence of matter and dark energy eras. Additionally, the new Barrow exponent $\Delta$ significantly affects the dark energy equation of state, and according to its value it can lead it to lie in the quintessence regime, in the phantom regime, or experience the phantom-divide crossing during the evolution. Finally, in the limiting case of maximal quantum-gravitational effects, Barrow holographic dark energy becomes constant and $\Lambda$CDM paradigm is restored, although through a completely different physical framework.
TL;DR: This paper focuses on several natural occurring phenolic acids (caffeic, carnosic, ferulic, gallic, p-coumaric, rosmarinic, vanillic) and gives an overview of their most common natural plant sources and reports on the latest literature evidence concerning specific biochemical properties of the examinedphenolic acids.
Abstract: Nature has generously offered a wide range of herbs (e.g., thyme, oregano, rosemary, sage, mint, basil) rich in many polyphenols and other phenolic compounds with strong antioxidant and biochemical properties. This paper focuses on several natural occurring phenolic acids (caffeic, carnosic, ferulic, gallic, p-coumaric, rosmarinic, vanillic) and first gives an overview of their most common natural plant sources. A summary of the recently reported antioxidant activities of the phenolic acids in o/w emulsions is also provided as an in vitro lipid-based model system. Exploring the interfacial activity of phenolic acids could help to further elucidate their potential health properties against oxidative stress conditions of biological membranes (such as lipoproteins). Finally, this review reports on the latest literature evidence concerning specific biochemical properties of the examined phenolic acids.
TL;DR: In this article, the use of different solar energy technologies in any kind of polygeneration system is investigated, including flat plate collector, evacuated tubes, parabolic trough collector, linear Fresnel reflector, solar dish concentrator, solar tower and thermal photovoltaics.