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Improved Surface Chemistry for Enhanced Electrochemical Performance of Zinc-Tin-Sulphide@CNTs
No full textThe intermittency of energy from fossil fuels and its anthropogenic impact on the ecosystem have led to a surge in the transition towards renewable and sustainable energy resources. Among renewable energy storage devices, supercapacitors are vital and require exploring new materials having the potential to deliver optimal energy performance. Transition metal sulphides are considered crucial for asymmetric supercapacitor, however, issues such as lower storage performance, ion transport and conductivity limit their application. In contrast, the binary transition metal sulphides (BTMS) inherently have higher storage performance, enhanced conductivity, better kinetics, and excellent cycle life performance. BTMS electrochemical performance can be further improved by blending with materials having surface functional groups such as carbon nanotubes (CNTs). Here, we have developed a composite material Zinc-Tin-Sulfide@Carbon-nanotubes (ZTS@CNTs) using hydrothermal synthesis to modify the surface chemistry for an enhanced storage performance. For which it has been found that, the specific surface area is enhanced by almost 10 times (from 7.79 m2 gβ1 to 78.78 m2 gβ1), capacity in three electrodes increased from 217 C gβ1 (for ZTS) to 344 C gβ1 (for ZTS@CNTs), and a considerable reduction in the electrolyte resistance from 1.30 Ξ© (ZTS) to 0.83 Ξ© (ZTS@CNTs). On the other hand, in a two-terminal setup, ZTS@CNTs as the positive electrode and CNTs as the negative electrode outperform ZTS//AC by delivering a high energy density of 45.75 W h kgβ1 in comparison to 28.18 W h kgβ1 achieved in the latter device. Furthermore, the developed devices were found to retain excellent stability by revealing 94% of their capacity after 3000 galvanostatic charge-discharge cycles
A genre-specific structure of subjective feeling in music listening: What do qawwΔlΔ« listeners feel?
Get PDFMost studies of subjective feeling categories in musical emotion use dimensional or categorical models to describe the different kinds of emotions induced by music. There are several data-driven approaches, of which one example is Zentner and colleaguesβ Geneva Emotions in Music Scale (GEMS), which proposes 10 terms which can parsimoniously describe emotional experiences with music. Ethnomusicologists, however, advocate approaches to music and emotion embedded in the cultural concepts of communities, and critiques of psychological approaches as WEIRD (Western, Educated, Industrialised, Rich and Democratic) throw doubt upon the generalisations of GEMS and similar models due to a generally monocultural participant sample. Such critiques become particularly salient for musical emotion in non-western genres such as qawwΔlΔ« which have clearly defined affective systems associated with them. This article applies a similar data-driven approach to experiences of musical emotion in qawwΔlΔ«, the South Asian Sufi music. This article presents two experiments focussing on regular listeners to qawwΔlΔ« at the shrine of the Sufi Hazrat Nizamuddin Auliya in Delhi. The first experiment seeks to determine which emotion words are most relevant to qawwΔlΔ« listening by presenting a list of terms for participants to rate, and selecting the terms most often felt with qawwΔlΔ«. The second compares these emotions using multidimensional scaling (MDS), and uses exploratory factor analysis (EFA) to determine a small number of factors which parsimoniously describe emotional experiences with qawwΔlΔ«. EFA suggests three factors describing subjective feelings with qawwΔlΔ«: virtuous feelings, spiritual love and trance
Fast, efficient piston correction of deployable space telescopes using machine learning
No full textAlignment of segmented telescopes is essential in creating an effective monolithic primary mirror. A fast, two-step piston sensing technique has been developed to enable diffraction-limited imaging. Achieving such performance requires a Strehl ratio exceeding 0.8, which corresponds to a wavefront RMS error below 32 nm at Ξ»β=β450 nm. A machine learning model has been implemented for a four-petal telescope to retrieve piston errors directly from PSF images and enable mirror correction. When tested on synthetic misalignments drawn from a uniform distribution within Β±300 nm (or Β±2Ξ»/3), the model improved the mean Strehl ratio from a degraded state to 0.95 after one iteration, and to 0.99 after a second iteration. An SNR greater than 40 was found sufficient to achieve phasing corresponding to a Strehl ratio of at least 0.97
Earthquakes act as a capacitor for terrestrial organic carbon
No full textEarthquakes and seismically-induced landslides accelerate carbon export from mountains by eroding hillslope soil carbon. However, a quantitative understanding of their net contribution to carbon cycling remains incomplete. Using the 2008 M 7.9 Wenchuan Earthquake which generated the largest landslide volume in recent history, we quantify its carbon mass balance accounting for storage, loss, and transport within the ensuing sediment cascade. Thanks to post-event revegetation and extensive intermontane sediment storage, we show that the earthquake boosted Longmenshan carbon mass by ~10%. Given the stability of these deposits and low rates of carbon export, we anticipate this landslide carbon will persist for centuries to millennia before gradually declining. In effect, we demonstrate that earthquakes and landslides function as capacitors, regulating carbon storage and discharge across mountain belts over time. This suggests frequent landslides in seismically-active mountains may lead to a net carbon sequestration, providing a critical and direct link between tectonics and the carbon cycle. [Abstract copyright: Β© 2026. The Author(s).
MeerKAT observations of Abell 1775 and Abell 1795: the discovery of a hadronic radio halo?
No full textGiant radio haloes are diffuse synchrotron sources typically found in merging galaxy clusters, while smaller mini-haloes occur in cool-core clusters. Both trace cosmic-ray electrons in the intracluster medium, though recent observations suggest their distinction is not always clear. We present new 903β1655 MHz MeerKAT observations of Abell 1775 and Abell 1795, both hosting cool cores and cold fronts. Combined with reprocessed 120β168 MHz LOFAR Two-metre Sky Survey data, we perform imaging and spectral analyses of their radio emission. In both clusters, we detect radio haloes with distinct inner and outer components. In Abell 1775, the halo appears diffuse at 1.3 GHz, while LOFAR images reveal steep-spectrum filaments. In Abell 1795, the inner component corresponds to a previously reported mini-halo candidate, but the full structure extends to 1 Mpc with a spectral index of . The presence of such a large, flat-spectrum halo in a dynamically relaxed cluster makes Abell 1795 an outlier relative to typical merging systems. This suggests that some relaxed clusters may still retain sufficient turbulence to sustain particle re-acceleration, or that hadronic interactions producing secondary electrons play a significant role. Together with other recent discoveries in cool-core systems, our results indicate that some large radio haloes may have been overlooked in past studies due to limited dynamic range near bright central AGN. Finally, we detect steep-spectrum emission south of Abell 1795βs central AGN, tracing a 45 kpc X-ray and optical filament that terminates in an X-ray cavity, likely linked to a past AGN outburst
Comparison of Rayleigh and sodium laser guide stars for improved ground-to-GEO communication
No full textAtmospheric turbulence limits satellite-to-ground free space optical communication. Adaptive optics at the ground station can correct for turbulence, but anisoplanatism limits the correction along the uplink, point-ahead angle, to the satellite. A laser guide star (LGS) can be used to measure the turbulence along the uplink path. This paper investigates pre-compensation of the uplink communication to a geo-stationary satellite using the two types of LGS used in astronomy (sodium and Rayleigh). The evaluation includes an error budget and a model analysis under different realistic atmospheric turbulence conditions. LGS based pre-compensation provides higher coupled flux and reduced fades, by βΌ 4 dB, versus downlink pre-compensation. While a high power (80 W) sodium LGS can result in higher mean coupled flux to the satellite, a lower power (15 W) Rayleigh LGS performs as well in terms of the probability of uplink transmission (i.e. reduced fades). We conclude that the uplink performance improvement, versus likely cost, with Rayleigh LGS is significant and warrants further exploration
From victimhood to empowerment: representing women in 1920s Soviet Georgian cinema: by Salome Tsopurashvili, London, Bloomsbury, 2025, 250 pp., 39 illustrations, index, $120 (hardback), ISBN 978-1501383175
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Multi-state detection and spatial addressing in a microscope for ultracold molecules
Get PDFPrecise measurement of the particle number, spatial distribution and internal state is fundamental to all proposed experiments with ultracold molecules both in bulk gases and optical lattices. Here, we demonstrate in-situ detection of individual molecules in a bulk sample of 87Rb133Cs molecules. Extending techniques from atomic quantum gas microscopy, we pin the molecules in a deep two-dimensional optical lattice and, following dissociation, collect fluorescence from the constituent atoms using a high-numerical-aperture objective. This enables detection of individual molecules up to the resolution of the sub-micron lattice spacing. Our approach provides direct access to the density distribution of small samples of molecules, allowing us to obtain precise measurements of density-dependent collisional losses. Further, by mapping two internal states of the molecule to different atomic species, we demonstrate simultaneous detection of the position and rotational state of individual molecules. Finally, we implement local addressing of the sample using a focused beam to induce a spatially-dependent light shift on the rotational transitions of the molecules
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