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Singletโtriplet gaps for evaluating thermally activated delayed fluorescence: which one is the (b) E ST?
No full textThe singletโtriplet energy gap (ฮEST) serves as a central screening parameter for new thermally activated delayed fluorescence (TADF) materials, and is a valuable indicator of eventual OLED performance. Surprisingly though, various measurement methodologies and reporting standards for ฮEST persist across the research community. The resulting variability undermines direct comparisons of material properties across reported works, obfuscating structureโproperty relationships that would otherwise guide synthetic efforts and computational validation. Here we employ 4CzPyz and 4tCzPyz as model systems, and correlate their different possible ฮEST values with their reverse intersystem crossing (rISC) kinetics in films of common and device-relevant hosts. By comparing ฮEST values with emission decay kinetics and device roll-off performance for these two materials, we propose that the steady-state room-temperature photoluminescence onset should be used to determine E(S1), in preference to either steady-state low-temperature or time-resolved singlet emission. Ultimately though, even this should only be taken as an indicator, as device performance is not always reliably predicted by comparing optically derived ฮEST gaps
Ultradiffuse Galaxies in the EAGLE Simulation
No full textWe use the highest-resolution EAGLE simulation, Recal-L025N0752, to study the properties and formation of ultradiffuse galaxies (UDGs). We identify 181 UDGs at z = 0 and find their properties are consistent with observations. The total masses of the EAGLE UDGs range from โผ5 ร 108 Mโ to โผ2 ร 1011 Mโ, indicating that they are dwarf galaxies rather than failed Lโ galaxies. The EAGLE UDGs are not a distinct population, but rather a subset of dwarf galaxies, as their properties generally form a continuous distribution with those of normal dwarf galaxies. Unlike most of the situations in previous studies, the extended sizes of the field UDGs in EAGLE are not driven by high halo spins or by supernova-induced stellar expansion, but instead largely arise from high spins in their star-forming gas and thus the newly formed stars at large radii. We hypothesize that this might be attributed to galactic fountains, via which star-forming gas is launched to large halocentric distances and acquires additional angular momentum through interactions with the circumgalactic medium. For satellite UDGs, โผ60% of them were already UDGs before falling into the host galaxy, while the remaining โผ40% were normal galaxies prior to infall and subsequently transformed into UDGs due to tidal effects after infall
A phenomenological study of the accretion disc in the super-Eddington AGN I Zw 1
Get PDFThe structure of the accretion disc in active galactic nuclei (AGN) is still an unsolved question, especially how it may change with Eddington ratio. Here we examine the accretion disc in the super-Eddington AGN I Zw 1 using reverberation mapping of the optical continuum. We use three years of optical monitoring with Las Cumbres Observatory at subday cadence in . The lag-wavelength spectrum, calculated using the cross-correlation method and pyroa, shows a u-band excess.pyroa lags are equally well fitted with a thin and slim disc profile. The ultra-violet/optical AGN spectral energy distribution is consistent with a thin disc. The disc size at for a thin disc model is and for a slim disc model is , larger by a factor of than the fiducial disc size of as determined using the Eddington ratio. We find evidence of different size scales probed with different variability time-scales. Lags evaluated at longer variability time-scales increase as do frequency-resolved lags at low frequencies, which we interpret as an additional secondary reprocessor at large radii consistent with the broad-line region (BLR) in I Zw 1. The high-frequency lags, predicted well with just a disc, are fit with a thin disc profile and a size of . This indicates that the actual disc size may be on the order of the fiducial size. We also collate the most extensive set of directly measured internal sizes of an AGN, from optical to mid-infrared with reverberation mapping and optical interferometry. Assuming that the disc is indeed the fiducial size, these show little evidence that the accretion disc extends into the BLR significantly, tentatively disfavouring the failed radiatively accelerated dust driven outflow BLR formation model
Evolutionary Approaches to Beauty
Get PDFIn Evolutionary Psychology, it is sometimes claimed that certain traits are universally considered as beautiful. In both sexes, these alleged universals have included having symmetrical facial and body traits, smooth, blemish-free skin, and sex-typical (masculine vs feminine) traits. In men, โbeautifulโ traits may include having a strong jawline, being tall, and possessing a muscular physique with broad shoulders. In women, youthful and feminine features are claimed to be preferred, such as large eyes, full lips, and a curvaceous yet slim body shape. According to evolutionary scholars, humans have evolved attraction to such traits because they signal important information about the individualโs biological condition; for example, that this individual is particularly healthy or fertile. While early researchโprimarily conducted in Western culturesโseemed to support this notion, more recent research has challenged this. For example, emerging cross-cultural research from non-Western cultures has demonstrated that, rather than being universal, beauty perceptions are malleable and vary considerably between cultures. Furthermore, when researchers test whether these traits are truly associated with health or fertility, we find that the evidence is weak and inconsistent. In this chapter, we therefore review extant evidence for evolutionary-derived hypotheses about the universality of beauty. We also discuss how narratives arguing that perceptions of beauty are fully evolvedโrather than malleableโare sometimes misused in the public domain by, for example, promoting ideas of biological determinism and justifying appearance-based discrimination, and we make recommendations for future research into this area
What factors shape the radio luminosity of star-forming galaxies? A new calibration from LoTSS-DR2
Get PDFRadio observations offer a dust-unobscured view of galaxy star formation via the radio continuumโstar formation rate (RCโSFR) relation. Emerging evidence of a stellar mass dependence in the RCโSFR relation raises the broader question of how other galaxy properties may influence this relation. In this work, we study the dependence of the global RCโSFR relation on galaxy properties in local ( 0.3) star-forming galaxies (SFGs) using the second data release of the LOw Frequency ARray (LOFAR) Two-Metre Sky Survey (LoTSS-DR2). Employing a non-parametric decision-tree regression algorithm, we identify the most important galaxy properties for estimating the radio luminosity using a sample of 18 828 emission-line-classified SFGs based on spectroscopic data from the Sloan Digital Sky Survey (SDSS)-DR8. Along with the spectroscopically obtained SFRs and stellar mass values, we also use SFRs and stellar masses derived using photometric spectral energy distribution-fitting from the GALEXโSDSSโWISE Legacy Catalogue for the same sample. We find that a galaxyโs SFR is most important for predicting the radio luminosity, followed by the stellar mass, at significance. Complementing the LoTSS catalogue 150 MHz flux densities with aperture photometry for the rest of the emission-line classified sample (35 099 galaxies in total), we obtain a new calibration of the RCโSFR relation, which does not change significantly whether we use spectroscopic or photometrically derived SFRs and stellar masses, despite the fact that the methods probe star formation on different characteristic time-scales. Our results highlight the utility of decision-tree algorithms for handling censored radio-selected galaxy samples, which will be useful for future spectroscopic surveys of radio sources
NNLO+NNLL Predictions for Heavy-Jet Mass and C-parameter in Higgs Decays to Quarks and Gluons
Get PDFMaintenance-Oriented Tunnel Digital Model Generation via Panoptic Segmentation of Ultra-High-Resolution Images
No full textUltra-high-resolution (UHR) panoramic imaging enables detailed capture of tunnel surface conditions. Nevertheless, damage detection and reporting still relies on manual annotations after the inspection, as existing automated algorithms typically require downsampling (losing fine details) or patch-based processing (loosing globalcontext) to handle the massive computational load of UHR data. This trade-off restricts the effective use of such high-fidelity data, leaving comprehensive reporting reliant on manual annotation. To address this gap, a novel framework has been proposed that directly operates on UHR panoramic images for automated damage detection and 3D reconstruction employing Building Information Modelling to createdigital model with annotated defects. At its core is a flexible segmentation architecture with a side network that enables context extraction from larger image patches, supporting panoptic segmentation of images over 6K resolution and accurate detectionof tunnel components and five main damage types. With the Segment Anything Model 2 backbone, performance further improves, raising panoptic quality from 53.14 to 56.99. Industry Foundation Classes open data format has been expended to support the standardized and interoperable representation of damaged tunnel, based on which an as-damaged BIM model is constructed to effective record and visualize inspection outcomes and quantitative significance level, thereby enhancing the efficiency of tunnel monitoring and management
Lowering Novice Programming Barriers with Medialib: Studies of its Effectiveness and Transferability
No full textUK Nutrition Research Partnership โHot Topicโ workshop report: A โgame changerโ for dietary health โ addressing the implications of sport sponsorship by food businesses through an innovative interdisciplinary collaboration
No full textOverweight and obesity is a global concern as a significant risk factor for non-communicable diseases. Increased energy intake due to greater consumption of energy-dense food or non-alcoholic beverages high in fat, saturated fat, sugar or salt (โHFSS foodโ) is the main explanation for population weight gain. The principal drivers underlying this consumption are the commercial determinants of health in the food chain, particularly the marketing of HFSS food. In the UK, some rules do regulate certain forms of HFSS food marketing (such as television and online advertising to children) and the government is considering strengthening these. However, although sports sponsorship by โHFSS food businessesโ (defined as a business preparing, cooking, storing, handling, distributing, supplying or selling food and whose products are primarily HFSS) is increasingly recognised as linked to HFSS food consumption, it has received little attention. This is all the more concerning in light of the recent proliferation of โHFSS food businessesโ and HFSS products partnering with sports organisations. Against this background, we hosted a workshop to focus on the relationship between health, nutrition and the sponsorship of sport and related marketing by โHFSS food businessesโ and to consider the implications for obesity prevention strategies in the UK and beyond. This innovative workshop capitalised on, and contributed to, ongoing efforts to conceptually unite existing research by bringing together an interdisciplinary team of experts providing unique and complementary perspectives on how to address sports sponsorship as one of the channels through which โHFSS food businessesโ contribute to poor nutrition and diet-related diseases. This report summarises the structure, participants and discussions from the workshop; the existing evidence base; and the future research and policy opportunities we plan to pursue
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