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Enhancing biochar quality for the steel industry via Hydrothermal Pretreatment-Steam Explosion and pyrolysis
Get PDFBiochar has potential applications in steelmaking processes, but faces technical challenges such as low material density, high alkali content, and high reactivity compared to coal. This study explores converting the solid residue, following hydrothermal pretreatment-steam explosion (HTP-SE) of Miscanthus and other biomass feedstocks, into biochar to facilitate the replacement of coal in blast furnace and electric arc furnace operations. It is the first to demonstrate the enhanced combustion characteristics of pretreated fibre and the compatibility of the biochar for use in steelmaking. Biomass from birch, miscanthus, wheat straw, both untreated and pretreated, was evaluated. HTP-SE was conducted at 192 °C and 1.3 MPa, conditions aligned with hemicellulose extraction for application in biobased products. Biochars were produced at temperatures ranging from 300 °C to 550 °C. HTP-SE increased the carbon, hydrogen, and energy content by approximately 10%, 8%, and up to 5 MJ/kg, respectively, while reducing ash quantity by up to 45%. In addition, it reduced the alkali and phosphorus content from the solid fraction into aqueous phase. Gas analysis indicated that HTP-SE enhanced the energy content of pyrolysis syngas. Thermogravimetric studies revealed that pretreated biochars exhibited significantly lower reactivity with carbon dioxide compared to untreated counterparts, approaching the reactivity of coal. This was attributed to increased aromaticity, C=C bonding, cross-linkages enriching lignin and by the removal of hemicellulose through HTP-SE. Overall, the upgraded biochar addresses key limitations of conventional biochar and shows strong potential as a substitute to replace injection coal entirely in both blast and electric arc furnaces.</p
Translating sanctuary:Politics of solidarity in a bilingual and plurinational context
Get PDFThis paper explores the rescaling of sanctuary to the national scale, distinct from the state scale. While scholarship has largely focussed on how sanctuary, hospitality and citizenship are provided at city scales, we analyse how substate nations respond to people seeking sanctuary by focussing on the case of Wales, an officially bilingual nation (multilingual in practice) within a plurinational state. By unpacking different meanings of Nation of Sanctuary (NoS)/Cenedl Noddfa (CN) in English and Welsh, we demonstrate the importance of adopting a ‘national gaze’ for complex, nuanced and heterogeneous understandings, rather than singular and homogenous assumptions (often associated with national perspectives). In interrogating etymology and meanings of sanctuary and delving into the (subtly) different meanings of lloches and noddfa, we illustrate the nuances and complexities of sanctuary politics and practices in a bilingual nation. This highlights the significance of considering the presence of competing, contrasting or complementary understandings of sanctuary in multilingual nations along with the various histories, cultures and ideas of belonging that shape sanctuary practices, rather than leaving translation as an afterthought. In uncovering the complexities and different meanings of NoS/CN, we develop a novel perspective on understandings of host/guest relations and provide an alternative way of understanding this dyadic distinction central to extant hospitality scholarship.</p
Intrasexual and intersexual territorial aggressive responses are repeatable and correlated in blue tits of both sexes
Get PDFAggressive behaviours are commonly expressed in the competition for limited resources and influence the survival and reproduction of individuals. However, because of a predominant focus on male–male competition and aggression, the importance of female aggression remains much less understood. In this study, we quantified both female and male aggressiveness in breeding blue tits, Cyanistes caeruleus, in response to same- and opposite-sex territorial intruders. We asked whether behavioural responses to same-sex and opposite-sex intruders were different. Using taxidermic mounts and song playback, we simulated territorial intrusions by female or male conspecifics during the nest-building and egg-laying stages of breeding blue tit pairs. First, females showed overall stronger aggressive responses than males. Furthermore, females were similarly aggressive towards female and male intruders, while males were less aggressive towards females than males. These observations demonstrate a sex-specific territorial response. Second, we found repeatable variation in the aggressive responses of both females and males. Remarkably, aggressive responses towards mounts of different sexes were strongly positively correlated. This result suggests that the aggressive responses of individuals in intrasexual and intersexual conflicts reflect the same underlying behavioural trait. We discuss possible functional explanations for our findings. Our findings highlight the importance of female aggression in a biparental territorial species, warranting further investigations into the ecological costs and benefits of individual differences in aggressiveness in both females and males.</p
Connections to trees in the countryside:Exploring public perceptions of agroforestry as a future land management system in England
No full textAgroforestry is increasingly recognised as an approach to deliver multi-functional land use and provide a range of ecosystem services. In England, rural agroforestry is an important part of the government’s net-zero strategy. However, the adoption rate is lower than the policy targets with agroforestry currently accounting for around 1% of the total agricultural area in rural England. Significant landscape change is therefore yet to emerge. To ensure sustainable benefits and be socially acceptable, landscape changes should take into account stakeholder preferences. This study explores people’s connections with trees in the countryside and their perceptions of benefits and risks associated with increased agroforestry in England. We report the results of focus group discussions involving 32 people across two economically, geographically, and agronomically contrasting regions of England (Northumberland/Tyne and Wear in the Northeast, and Thames Valley in the Southeast). The participants articulated an appreciation and enjoyment of established trees in the landscape and referred to social, emotional, and physical connections. Agroforestry systems were seen as generally positive, providing more ecosystem services than disservices. The participants associated a number of environmental and social benefits with the increase in tree cover in the countryside. However, they also stressed the need to ensure that the right tree is planted in the right place so that agroforestry does not negatively impact on the landscape. Our results suggest that there is public support for increased agroforestry adoption, but the incentive schemes should be carefully designed to reflect stakeholder preferences and values and maximize public benefits.</p
Above-ionization synchrotron-excited silicon-based nanograins by x-ray and EUV radiation:Implications to grain stability and shielding in planetary nebulae
No full textWe use silicon-based nanograins as model nanodust in planetary nebulae and present photo-excitation and stability studies using synchrotron extreme ultraviolet radiation, while monitoring the induced cascade of visible/UV luminescence. We also conduct theoretical studies (atomistic simulations and classical Mie scattering), as well as stability studies of the grains under long-wavelength UV excitation using lasers or discharge lamps or under thermal treatments. We report that the luminescence of 1-nm grains remains stable for above ionization limit excitation [5-22 eV, 1012 (photons/cm2)/s]. Under excitation below the ionization limit, using lasers or discharge lamps (3.5 eV, 1014/cm2/s) or under thermal treatment, the luminescence exhibits partial stability at a steady ∼50%, with slow partial recovery. Time-dependent density functional theory shows the structural stability of neutral or ionized ultrasmall nanograins, while organic dye molecules are fully quenched with no recovery. Computations also show the enhancement of scattering of soft x rays over the geometrical cross section. We analyze the results in terms of quantum confinement induced effects, including inhibition of e-h and e-Coulomb scattering, enhancement of e-e correlation, and relativistic e-vibration coupling. These effects lead to multi-electron excitation, singlet-triplet intersystem conversion, and plasmon-type Mie “polarizmon scattering” by valence electrons. Such novel characteristics point to the survivability of ultrasmall grains in x-ray or UV environments, which may serve as a UV shield for large interstellar molecules, necessary to life.</p
JWST/NIRSpec Detection of Complex Structures in Saturn's Sub-Auroral Ionosphere and Stratosphere
No full textPast observations of Saturn's sub-auroral ionosphere have provided no detailed longitudinal information, and variations in underlying stratospheric emission from methane fluorescence have never been resolved spatially. Here, we present the first near-infrared observations of Saturn using JWST's NIRSpec-IFU, revealing the 2.8–5.2 micron wavelength region in unprecedented detail. We observe the rotating auroral enhancement associated with planetary-period currents, the phase of which is re-discovered for the first time since Cassini. We discover a series of ionospheric dark beads located between 55 and 65 (Formula presented.) N, that appear to be formed by local thermospheric dynamics. In the fluorescing methane, we reveal strange dark arms extending equatorward from a dark polar cap at 60 (Formula presented.) N; four arms from a six-pointed star, each extend below 45 (Formula presented.) N with the final two arms missing. Neither set of features has any known analog at other planets.</p
Dominant Drivers of Jupiter's H<sup>+</sup><sub>3</sub> Northern Aurora 1:Magnetic Field Strength and Planetary Local Time
No full textJupiter's auroral regions are marked by considerable spatial and temporal variability, with numerous sources of auroral enhancements, making it difficult to isolate individual causes of emission brightness. Here, we utilize a data set of (Formula presented.) 13,000 near-infrared (Formula presented.) images of Jupiter mapped into latitude, longitude and planetary local time to separate out various sources of emission brightening, smoothed over hundreds of hours of integration and tens of days of observing. We show that (Formula presented.) equatorial emission is well correlated to planetary local time, indicating that equatorial ionospheric emission is dominated by solar Extreme Ultraviolet (EUV) ionization on the dayside of the planet. (Formula presented.) main auroral emission is strongly anti-correlated with surface magnetic field strength (with a Pearson correlation of (Formula presented.) −0.90), and is also strongly correlated with planetary local time (changing in brightness in the same way as equatorial emission with a Pearson correlation of (Formula presented.) 0.93). This is the first time such strong correlations have been shown at Jupiter, and may be the first evidence of such direct correlations at any planet, including Earth. Both of these correlations are thought to ultimately result from changes in ionospheric electrical conductivity driven by changing magnetic field strength and solar EUV ionization. This suggests the (Formula presented.) aurora is significantly controlled by breakdown in co-rotation currents flowing deep into the ionosphere, and that this deep layer contains an important component of solar ionization. However, polar auroral emission does not correlate well with planetary local time, suggesting much more complex processes drive the varying emission within this region.</p
Fixing Background Misclassification in Few-Shot Object Detection via Product of Experts
No full textFew-shot object detection (FSOD) poses a significant challenge due to the difficulty of learning robust and discriminative object representations under limited supervision. A widely adopted solution is the two-stage fine-tuning framework, wherein knowledge acquired from a large-scale base dataset is transferred to a novel dataset containing only a small number of labeled instances. However, this framework is prone to systematically misclassifying novel objects as background, primarily due to incorrect background label caused by the domain gap between base and novel datasets—an issue exacerbated by the sparse representation of novel categories. In this work, we show that this inherent weakness can be exploited by explicitly redefining the category structure and transferring the representations learned during the base training stage. Building on this insight, we propose a simple yet effective framework grounded in the Product of Experts (PoE) formulation, which estimates the joint distribution over background and novel categories by combining the unnormalized logits from independently trained classifiers. Notably, it does not require modifications of the base model or repetition of the base training phase. Furthermore, we introduce a strategy for identifying additional novel-category instances within the base dataset, which effectively augmenting the training set for fine-tuning. The resulting method is architecture-agnostic, imposes negligible overhead, and integrates seamlessly with existing two-stage fine-tuning pipelines. Extensive experiments on PASCAL VOC and COCO demonstrate that the proposed method yields consistent improvements across different baselines, achieving significant gains over state-of-the-art FSOD approaches.</p
A Silurian asymmetric compound delta system in south central Wales, UK
No full textGorstian sediments in south-central Wales preserve an asymmetric, compound mixed-process delta system north of the Carreg Cennen Disturbance and east of the Golden Grove Axis. The 30 km SW-NE outcrop, extending from the Cennen Valley to Y Pigwn, is oblique to the NNE delta progradation direction. The Hafod Fawr Formation comprises subaqueous delta slope deposits. Sandstone bed amalgamation indicates shoaling and wave/storm influence within the overlying subaqueous delta platform deposits of the Cwar Glas Member. The succeeding Mynydd Myddfai Sandstone Formation contains shoreline delta lithofacies within three geographical tracts. An embryonic Golden Grove Axis shed shoal water shoreline fan-delta and alluvial fan lithofacies (of the Trichrug Formation) in the Cennen Valley Tract. The SW Tract (Cilmaenllwyd to Banc Celynog) was deposited on the updrift flank of the asymmetric delta, with longshore drift to the NE. Amalgamated sandstone bedsets dominate in the mouth bar and terminal distributary channel lithofacies. Pen y Bicws preserves the axial gravel bed distributary channel lithofacies, which created a headland and palaeogeographic divide between the SW and NE tracts. The latter (Sawdde Gorge to Y Pigwn) records deposition in a low-energy bay that hosted cycles of heterolithic lithofacies. Collectively, these tracts occupied part of a sediment supply route to deeper facies of the subsidence-prone Clun Forest Sub-Basin. Emergent delta plain deposits become dominant within the overlying Trichrug Formation. Thin, locally preserved deposits of the Cribyn Du Member record delta abandonment and transgression during the Ludfordian associated with basin reconfiguration and expansion of the Caer'r mynach Seaway.</p
Adjustment of paternal care in response to experimental variation in extra-pair mating opportunity in male zebra finches
No full textExtra-pair paternity is prevalent in socially monogamous bird species with biparental care. Male extra-pair matings may coincide with paternal care provisioned to within-pair offspring. This may lead to a trade-off between obtaining additional fertilizations and securing offspring growth and survival through paternal care. In this pre-registered study, we manipulated the social environment of zebra finches to investigate how males trade off extra-pair mating versus providing paternal care. We compared paternal care provision between a social environment where two pairs bred together in a cage—resulting in an opportunity for extra-pair mating (Double-pair group)—to one with single breeding pairs (Single-pair group). We additionally measured plasma testosterone and corticosterone to identify hormonal correlates of male behavioral responses. To further increase the opportunity for extra-pair mating for the focal males from the Double-pair group we removed the male of the non-focal pair during chick rearing by the focal males. Contrary to our predictions, Double-pair males incubated more than Single-pair males. While we found substantial extra-pair paternity in the Double-pair group after removal of the non-focal males, male brood provisioning, chick growth and survival, and testosterone levels were not affected by the experimental increase in male extra-pair mating opportunity. Corticosterone levels were higher in Single-pair males between the first and replacement clutch. Refuting common assumptions, our findings provide no experimental evidence for a trade-off between extra-pair mating and paternal care. Males were able to pursue extra-pair fertilizations while they simultaneously secured the growth and survival of their within-pair offspring.</p