577 research outputs found
Thixotropic gel electrolyte containing poly(ethylene glycol) with high zinc ion concentration for the secondary aqueous Zn/ LiMn2O4 battery
The final publication is available at Elsevier via https://doi.org/10.1016/j.jelechem.2019.01.014 Ā© 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/We have designed an aqueous gel electrolyte containing fumed silica as the thixotropic gelling agent and poly(ethylene glycol) (MW = 300 gĀ·molā1) as the non-thixotropic gelling agent. Poly(ethylene glycol) is also the dendrite suppressor and the corrosion inhibitor. Both PEG300 and fumed silica can inhibit dendrite formation, shown by chronoamperometry results and ex-situ scanning electron microscopy images. Furthermore, the corrosion current density on the Zn anode in the 4 wt%FS-1 wt%PEG300 gel electrolyte is 27% less than that of the Zn in the reference aqueous electrolyte. Secondary Zn/LiMn2O4 batteries using the 4 wt%FS-1 wt%PEG300 gel electrolyte exhibit higher cyclability (12% and 39% higher capacity retention, after 300 and 1000 cycles, in Swagelok and large cells, respectively) than those using the reference aqueous electrolyte. The vast improvements in cycling performance, reliability, and higher resistance to premature failure makes the PEG-FS gel a much better alternative to liquid electrolytes for maintenance-free energy storage applications.Positec Canada Ltd, Mitac
Search for new phenomena in multi-body invariant masses in events with at least one isolated lepton and two jets using ās = 13 TeV protonāproton collision data collected by the ATLAS detector
A search for resonances in events with at least one isolated lepton (e or Ī¼) and two jets is performed using 139 fb ā1 of s = 13 TeV protonāproton collision data recorded by the ATLAS detector at the LHC. Deviations from a smoothly falling background hypothesis are tested in three- and four-body invariant mass distributions constructed from leptons and jets, including jets identified as originating from bottom quarks. Model-independent limits on generic resonances characterised by cascade decays of particles leading to multiple jets and leptons in the final state are presented. The limits are calculated using Gaussian shapes with different widths for the invariant masses. The multi-body invariant masses are also used to set 95% confidence level upper limits on the cross-section times branching ratios for the production and subsequent decay of resonances predicted by several new physics scenarios. [Figure not available: see fulltext.]
Measurement of the total cross section and Ļ -parameter from elastic scattering in pp collisions at ās=13 TeV with the ATLAS detector
In a special run of the LHC with Ī²ā= 2.5 km, protonāproton elastic-scattering events were recorded at s=13 TeV with an integrated luminosity of 340Ī¼b-1 using the ALFA subdetector of ATLAS in 2016. The elastic cross section was measured differentially in the Mandelstam t variable in the range from - t= 2.5 Ā· 10 - 4 GeV 2 to - t= 0.46 GeV 2 using 6.9 million elastic-scattering candidates. This paper presents measurements of the total cross section Ļtot , parameters of the nuclear slope, and the Ļ -parameter defined as the ratio of the real part to the imaginary part of the elastic-scattering amplitude in the limit tā 0 . These parameters are determined from a fit to the differential elastic cross section using the optical theorem and different parameterizations of the t-dependence. The results for Ļtot and Ļ are Ļtot(ppāX)=104.7Ā±1.1mb,Ļ=0.098Ā±0.011. The uncertainty in Ļtot is dominated by the luminosity measurement, and in Ļ by imperfect knowledge of the detector alignment and by modelling of the nuclear amplitude
Search for top-philic heavy resonances in pp collisions at s=13Ā TeV with the ATLAS detector
A search for the associated production of a heavy resonance with a top-quark or a top-antitop-quark pair, and decaying into a ttĀÆ pair is presented. The search uses the data recorded by the ATLAS detector in pp collisions at s=13Ā TeV at the Large Hadron Collider during the years 2015ā2018, corresponding to an integrated luminosity of 139Ā fb-1. Events containing exactly one electron or muon are selected. The two hadronically decaying top quarks from the resonance decay are reconstructed using jets clustered with a large radius parameter of R=1. The invariant mass spectrum of the two top quark candidates is used to search for a resonance signal in the range of 1.0Ā TeV to 3.2Ā TeV. The presence of a signal is examined using an approach with minimal model dependence followed by a model-dependent interpretation. No significant excess is observed over the background expectation. Upper limits on the production cross section times branching ratio at 95% confidence level are provided for a heavy Zā² boson based on a simplified model, for Zā² mass between 1.0Ā TeV and 3.0Ā TeV. The observed (expected) limits range from 21Ā (14)Ā fb to 119Ā (86)Ā fb depending on the choice of model parameters
A precise measurement of the Z-boson double-differential transverse momentum and rapidity distributions in the full phase space of the decay leptons with the ATLAS experiment atĀ s=8Ā TeV
This paper presents for the first time a precise measurement of the production properties of the ZĀ boson in the full phase space of the decay leptons. This is in contrast to the many previous precise unfolded measurements performed in the fiducial phase space of the decay leptons. The measurement is obtained from protonāproton collision data collected by the ATLAS experiment in 2012 at s=8 TeV at the LHC and corresponding to an integrated luminosity of 20.2Ā fb-1. The results, based on a total of 15.3 million Z-boson decays to electron and muon pairs, extend and improve a previous measurement of the full set of angular coefficients describing Z-boson decay. The double-differential cross-section distributions in Z-boson transverse momentumĀ pT and rapidityĀ y are measured in the pole region, defined as 80<māā<100 GeV, over the range |y|<3.6. The total uncertainty of the normalised cross-section measurements in the peak region of the pT distribution is dominated by statistical uncertainties over the full range and increases as a function of rapidity from 0.5ā1.0% for |y|<2.0 to 2-7% at higher rapidities. The results for the rapidity-dependent transverse momentum distributions are compared to state-of-the-art QCD predictions, which combine in the best cases approximate N4LL resummation with N3LO fixed-order perturbative calculations. The differential rapidity distributions integrated overĀ pT are even more precise, with accuracies from 0.2ā0.3% forĀ |y|<2.0 toĀ 0.4ā0.9% at higher rapidities, and are compared to fixed-order QCD predictions using the most recent parton distribution functions. The agreement between data and predictions is quite good in most cases
Search for third-generation vector-like leptons in pp collisions at ās = 13 TeV with the ATLAS detector
A search for vector-like leptons in multilepton (two, three, or four-or-more electrons plus muons) final states with zero or more hadronic Ļ-lepton decays is presented. The search is performed using a dataset corresponding to an integrated luminosity of 139 fbā1 of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the LHC. To maximize the separation of signal and background, a machine-learning classifier is used. No excess of events is observed beyond the Standard Model expectation. Using a doublet vector-like lepton model, vector-like leptons coupling to third-generation Standard Model leptons are excluded in the mass range from 130 GeV to 900 GeV at the 95% confidence level, while the highest excluded mass is expected to be 970 GeV. [Figure not available: see fulltext.]
Search for resonant production of dark quarks in the dijet final state with the ATLAS detector
This paper presents a search for a new Zā² resonance decaying into a pair of dark quarks which hadronise into dark hadrons before promptly decaying back as Standard Model particles. This analysis is based on proton-proton collision data 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 fbā1. After selecting events containing large-radius jets with high track multiplicity, the invariant mass distribution of the two highest-transverse-momentum jets is scanned to look for an excess above a data-driven estimate of the Standard Model multijet background. No significant excess of events is observed and the results are thus used to set 95% confidence-level upper limits on the production cross-section times branching ratio of the Zā² to dark quarks as a function of the Zā² mass for various dark-quark scenarios
Global, regional, and national incidence, prevalence, and years lived with disability for 354 Diseases and Injuries for 195 countries and territories, 1990-2017: A systematic analysis for the Global Burden of Disease Study 2017
Copyright Ā© 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Background: The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017) includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data. Methods: We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting. Findings: Globally, for females, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and haemoglobinopathies and haemolytic anaemias in both 1990 and 2017. For males, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and tuberculosis including latent tuberculosis infection in both 1990 and 2017. In terms of YLDs, low back pain, headache disorders, and dietary iron deficiency were the leading Level 3 causes of YLD counts in 1990, whereas low back pain, headache disorders, and depressive disorders were the leading causes in 2017 for both sexes combined. All-cause age-standardised YLD rates decreased by 3Ā·9% (95% uncertainty interval [UI] 3Ā·1-4Ā·6) from 1990 to 2017; however, the all-age YLD rate increased by 7Ā·2% (6Ā·0-8Ā·4) while the total sum of global YLDs increased from 562 million (421-723) to 853 million (642-1100). The increases for males and females were similar, with increases in all-age YLD rates of 7Ā·9% (6Ā·6-9Ā·2) for males and 6Ā·5% (5Ā·4-7Ā·7) for females. We found significant differences between males and females in terms of age-standardised prevalence estimates for multiple causes. The causes with the greatest relative differences between sexes in 2017 included substance use disorders (3018 cases [95% UI 2782-3252] per 100 000 in males vs 1400 [1279-1524] per 100 000 in females), transport injuries (3322 [3082-3583] vs 2336 [2154-2535]), and self-harm and interpersonal violence (3265 [2943-3630] vs 5643 [5057-6302]). Interpretation: Global all-cause age-standardised YLD rates have improved only slightly over a period spanning nearly three decades. However, the magnitude of the non-fatal disease burden has expanded globally, with increasing numbers of people who have a wide spectrum of conditions. A subset of conditions has remained globally pervasive since 1990, whereas other conditions have displayed more dynamic trends, with different ages, sexes, and geographies across the globe experiencing varying burdens and trends of health loss. This study emphasises how global improvements in premature mortality for select conditions have led to older populations with complex and potentially expensive diseases, yet also highlights global achievements in certain domains of disease and injury
Searches for lepton-flavour-violating decays of the Higgs boson into eĻ and Ī¼Ļ in ās = 13 TeV pp collisions with the ATLAS detector
This paper presents direct searches for lepton flavour violation in Higgs boson decays, H ā eĻ and H ā Ī¼Ļ, performed using data collected with the ATLAS detector at the LHC. The searches are based on a data sample of proton-proton collisions at a centre-of-mass energy s = 13 TeV, corresponding to an integrated luminosity of 138 fb ā1. Leptonic (Ļ ā āĪ½ā Ī½Ļ) and hadronic (Ļ ā hadrons Ī½Ļ) decays of the Ļ-lepton are considered. Two background estimation techniques are employed: the MC-template method, based on data-corrected simulation samples, and the Symmetry method, based on exploiting the symmetry between electrons and muons in the Standard Model backgrounds. No significant excess of events is observed and the results are interpreted as upper limits on lepton-flavour-violating branching ratios of the Higgs boson. The observed (expected) upper limits set on the branching ratios at 95% confidence level, B (H ā eĻ) < 0.20% (0.12%) and B (H ā Ī¼Ļ) < 0.18% (0.09%), are obtained with the MC-template method from a simultaneous measurement of potential H ā eĻ and H ā Ī¼Ļ signals. The best-fit branching ratio difference, B (H ā Ī¼Ļ) ā B (H ā eĻ), measured with the Symmetry method in the channel where the Ļ-lepton decays to leptons, is (0.25 Ā± 0.10)%, compatible with a value of zero within 2.5Ļ. [Figure not available: see fulltext.]
Measurement of the production cross-section of J/Ļ and Ļ(2S) mesons in pp collisions at s=13Ā TeV with the ATLAS detector
Measurements of the differential production cross-sections of prompt and non-prompt J/Ļ and Ļ(2S) mesons with transverse momenta between 8 and 360Ā GeV and rapidity in the range |y|<2 are reported. Furthermore, measurements of the non-prompt fractions of J/Ļ and Ļ(2S), and the prompt and non-prompt Ļ(2S)-to-J/Ļ production ratios, are presented. The analysis is performed using 140Ā fb-1 of s=13Ā TeV pp collision data recorded by the ATLAS detector at the LHC during the years 2015ā2018
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