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Coagulation Performance of
No full textThe tofu processing industry generates significant amounts of wastewater, causing serious environmental challenges in Manokwari, West Papua. Protein extracted from Terminalia catappa seeds has potential as a natural coagulant for reducing the Total Suspended Solids (TSS) and turbidity in tofu wastewater. In this study, protein Terminalia catappa seeds (PTcS) were characterized using Fourier transform infrared spectroscopy (FTIR), and the effects of coagulant dosage and coagulation time on pH, TSS removal, and turbidity reduction were investigated. The results demonstrated that the coagulation efficiency of protein from Terminalia catappa seeds strongly depended on the wastewater pH. The optimum coagulant dosage was 1.2 g/L, achieving TSS and turbidity removal efficiencies of 90.74% and 57.55%, respectively, with an optimum coagulation time of 5 min. FTIR spectra revealed the presence of hydroxyl, aromatic, and carbonyl groups, indicating that phenolic compounds and proteins were the main active components contributing to coagulation. These findings highlight the potential application of Terminalia catappa seed as an eco-friendly and effective coagulant for tofu wastewater treatment
La mécanique quantique, une merveilleuse théorie… que chacun interprète à sa façon
No full textPour le troisième article de la série Regards sur les sciences et technologies quantiques, Reflets de la Physique aborde un sujet lié aux fondements mêmes de la discipline, celui de l’interprétation de la mécanique quantique. Reflets de la Physique a demandé à Franck Laloë de résumer les idées exposées dans son livre intitulé Comprenons-nous vraiment la mécanique quantique ? consacré aux fondements de la mécanique quantique. Ce livre présente en effet dans sa dernière partie un panorama général des différentes interprétations, les premières parties étant consacrées à un exposé historique sur la naissance des concepts quantiques et leur développement, à l’impact des idées de Bell et de son théorème et à leurs applications récentes à de nombreux domaines. Il était en fait impossible de résumer ce livre en quelques pages, mais nous remercions l’auteur d’avoir accepté de donner dans l’article qui suit un aperçu équilibré des principales interprétations de la mécanique quantique, dont certaines restent complexes et difficiles à appréhender et sont toujours discutées aujourd’hui entre physiciens et épistémologues
Galactic and solar energetic particle observations during the increasing part of solar cycle 25 with EPD/HET and Metis on board Solar Orbiter
No full textContext. Galactic cosmic rays (GCRs) and solar energetic particles (SEPs) with energies greater than tens of megaelectron volts are at the origin of spacecraft deep charging. The High Energy Telescope of the Energetic Particle Detector instrument measures the particle flux incident on the Solar Orbiter spacecraft. An algorithm implemented in the processing electronics of the visible light (VL) instrument of the Metis coronagraph generates cosmic-ray matrices containing the pixels fired by high-energy particles. These independent observations allow us to monitor the secondary particle production into the spacecraft.
Aims. We studied the GCR flux long-term variations during the ascending phase of solar cycle 25 and the evolution of two SEP events observed on July 24–26, 2023, and on February 9–14, 2024, above 80 MeV with the aim of evaluating the impact of galactic and solar high-energy particles on Metis.
Methods. A Python tool named REBECCA has been developed for the automated analysis of the Metis cosmic-ray matrices. The number of observed particle tracks is compared to Monte Carlo simulations of the Metis VL bidimensional CMOS sensor used as a particle detector.
Results. We present the modulation of the GCR energy spectrum from 2020 through 2024 above 100 MeV. The dynamics of two intense SEP events is also reported. Monte Carlo simulations indicate that the composition of particles in the cosmic-ray matrices is dominated by protons. Going from solar minimum to maximum, an increase in particles produced by cosmic rays in the spacecraft material surrounding Metis was observed. Conversely, during the whole evolution of SEP events, protons made up more than 90% of the particles. These observations were gathered near the ecliptic during a positive polarity epoch of the global solar magnetic field. Analogous studies will be conducted during the negative polarity epoch, within 1 au, both above and below the ecliptic plane, throughout the remaining duration of the mission
Multi-height probing of horizontal flows in the solar photosphere
No full textContext. Optical flow methods aim to infer horizontal (transverse, in the general case) velocities in the solar atmosphere from the temporal changes in maps of physical quantities, such as intensity or magnetic field. So far, these methods have mostly been tested and applied to the continuum intensity and line-of-sight (LOS) magnetic field in the low to mid-photosphere.
Aims. We tested whether simultaneous spectropolarimetric imaging in two magnetically sensitive optical spectral lines, which probe two different layers of the solar atmosphere (the photosphere and the temperature minimum), can help constrain the depth variation of horizontal flows.
Methods. We first tested the feasibility of our method using Fourier local correlation tracking (FLCT) to track physical quantities at different optical depths (log τ500 = −1, −2, −3, −4) in an atmosphere simulated with the MURaM code. We then inferred the horizontal distribution of the LOS magnetic field component from synthetic spectropolarimetric observations of Fe I 525.0 nm and Mg I b2 spectral lines, applied FLCT to the time sequence of these synthetic magnetograms, and compared our findings with the original height-dependent horizontal velocities.
Results. Tracking the LOS magnetic field component (which coincides with the vertical component at the disk center) yields horizontal velocities that, after appropriate temporal and spatial averaging, agree excellently with the horizontal component of the simulated velocities, both calculated at constant τ500 surfaces, up to the temperature minimum (log τ500 = −3). When tracking the temperature at constant τ500 surfaces, this agreement already breaks down completely at the mid photosphere (log τ500 = −2). Tracking the vertical component of the magnetic field inferred from synthetic observations of the Fe I 525.0 nm and the Mg I b2 spectral lines yields a satisfactory inference of the horizontal velocities in the mid-photosphere (log τ500 ≈ −1) and the temperature minimum (log τ500 ≈ −3), respectively.
Conclusions. Our results indicate that high-spatial-resolution spectropolarimetric imaging in solar spectral lines can provide meaningful information about the horizontal plasma velocities over a range of heights
Delayed maximum energy solar energetic particle events
No full textInvestigations of solar energetic particles (SEPs) have long utilized the dispersive nature of onset times, as in, the earlier arrival of higher-energy particles compared to lower-energy particles, to infer information such as the path length to the acceleration site at the time of initial particle release. However, recent observations by Solar Orbiter and Parker Solar Probe have begun to characterize SEP events with an apparent delay in arrival times of the higher energy portion of the particle distribution, above a critical energy separating the delayed particles from that of the typical velocity dispersion signature at lower energies. Features of these delayed maximum energy (DME) SEP events, sometimes referred to as “inverse velocity dispersion” events, could provide new insight into the impacts of magnetic connectivity to locations along an expanding coronal mass ejection-driven (CME-driven) shock wave, variations of acceleration along the shock surface, and transport effects in the inner heliosphere. This study focuses on the occurrence rate and characteristics of DME events observed by Solar Orbiter relative to their footpoint locations with respect to the initial flare site. These DME events show a bias in occurrence rate towards events when the observer’s footpoints were westward of the associated flare location. Additionally, estimated locations at which the highest-energy particles of DME events are released into the flux tube suggest continued release of increasingly higher-energy particles from the CME-driven shock into the connected flux tube well into the inner heliosphere. This indicates that DME events could be attributed to inner heliospheric effects and are not actually coronal in origin. This finding is consistent with previous observations and interpretations of SEP events connected westward of the associated flare
Study on charging models for cloud manufacturing supply chains considering data security under blockchain traceability technology
No full textBlockchain traceability technology enhances supply chain transparency and data security in cloud manufacturing supply chain, thereby affecting the choice of charging models. This paper innovatively integrates blockchain traceability technology with cloud data security management to construct a cloud manufacturing supply chain model that includes operators and suppliers. It conducts an in-depth analysis of equilibrium decisions under different charging models across varying levels of blockchain traceability technology, and designs a cost-sharing and revenue-sharing contract to coordinate the interests of all parties in the supply chain. It identifies four important results. First, as the level of blockchain traceability technology transitions from weak to strong, the service price, market demand, and profit levels for all parties in the cloud manufacturing supply chain show significant improvement. Second, the sensitivity coefficient of blockchain traceability technology and the elasticity coefficient of cloud data security positively influence the cloud data security level, blockchain traceability technology level, service price, demand, and profit, whereas the associated cost coefficients exert a negative influence. Third, he combined cost-sharing-revenue-sharing contract exhibits strong robustness and can effectively coordinate the cloud manufacturing supply chain, achieving Pareto improvement. Fourth, the strategic choices of the operator and the supplier are highly dependent on the revenue-sharing ratio. Both excessively high and low ratios lead to preference misalignment, which is further exacerbated by the cost coefficients of blockchain traceability technology and cloud data security management. However, when the ratio lies within a specific intermediate range, both parties consistently favor the revenue-sharing model. Increases in the sensitivity coefficient of blockchain traceability technology and the elasticity coefficient of cloud data security further widen this cooperative range
New traveling-wave solutions for time-fractional generalized Hunter-Saxton model in nematic liquid crystals: A separation of variables approach
No full textIn this paper, a comprehensive analytical study of the time-fractional generalized Hunter-Saxton model is presented using a separation of variables approach. The model governs the propagation of orientation waves in massive nematic liquid crystals and exhibits intrinsic links to Einstein-Weyl geometric structures. Incorporating a fractional-order time derivative introduces temporal nonlocality, capturing memory-driven effects in the evolution of nonlinear reorientation fronts. An exact reduction to the traveling-wave frame yields closed-form families of solutions representing smooth, kink-type, and singular fronts that propagate at constant speed. For generic parameter regimes, algebraic profiles arise, while a resonant limit produces a smooth exponential front. The analysis further confirms the absence of real periodic traveling waves. Visualization of the exact solutions through three-dimensional surface, contour, and density plots reveals the influence of the fractional order on wave steepening, front morphology, and propagation dynamics, offering theoretical insights relevant to experimental exploration of reorientation phenomena in complex liquid-crystalline media
SN Ia 2025bvm in the Seyfert galaxy NGC 4156: Early detection and follow-up observations
No full textAims. We investigated the photometric and spectroscopic evolution of SN Ia 2025bvm to perform a detailed classification and provide an independent distance estimate for the host galaxy NGC 4156.
Methods. We present UBVRI photometry for a period between days −16 and 80 relative to the B-band maximum. Six optical spectra were taken between days −3 and 28. We used different fitting methods to derive the basic photometric parameters. We determined the expansion velocities from the blueshift of the Si II absorption line and the equivalent widths of the interstellar Na I lines.
Results. SN 2015bvm exhibits a photometric evolution typical for Type Ia supernovae; the Δm15 parameter and the rise time are both close to their mean values. The rising part of the light curves shows no signs of excess flux. The color curves indicate a significant color excess of E(B − V)tot = 0.22 ± 0.04 mag. The interstellar Na I lines in the host galaxy are stronger than expected for this value of dust extinction. SN 2025bvm is notable for its high expansion velocity at maximum light and the presence of a plateau in the velocity temporal evolution. We estimate a distance modulus of μ = 34.84 ± 0.10 mag, consistent with the value derived from the host galaxy redshift
The ALMA survey to Resolve exoKuiper belt Substructures (ARKS)
No full textContext. Debris discs are analogues to our own Kuiper belt around main-sequence stars and are therefore referred to as exoKuiper belts. They have been resolved at high angular resolution at wavelengths spanning the optical/near-infrared to the submillimetre-millimetre regime. Short wavelengths can probe the light scattered by such discs, which is dominated by micron-sized dust particles, while millimetre wavelengths can probe the thermal emission of millimetre-sized particles. Determining differences in the dust distribution between millimetre- and micron-sized dust is fundamental to revealing the dynamical processes affecting the dust in debris discs.
Aims. We aim to compare the scattered light from the discs of the ‘ALMA survey to Resolve exoKuiper belt Substructures’ (ARKS) with the thermal emission probed by ALMA. We focus on the radial distribution of the dust, and we also put constraints on the presence of giant planets in those systems.
Methods. We used high-contrast scattered light observations obtained with VLT/SPHERE, GPI, and the HST to uniformly study the dust distribution in those systems and compare it to the dust distribution extracted from the ALMA observations carried out in the course of the ARKS project. We also set constraints on the presence of planets by using these high-contrast images combined with exoplanet evolutionary models.
Results. Fifteen of the 24 discs comprising the ARKS sample are detected in scattered light, with TYC 9340-437-1 being imaged for the first time at near-infrared wavelengths. For six of those 15 discs, the dust surface density seen in scattered light peaks farther out compared to that observed with ALMA. These six discs except one are known to also host cold CO gas. Conversely, the systems without significant offsets are not known to host gas, except one. Moreover, with our scattered light near-infrared images, we achieve typical sensitivities to planets from 1 to 10 MJup beyond 10 to 20 au, depending on the system age and distance.
Conclusions. This observational study suggests that the presence of gas in debris discs may affect the small and large grains differently, pushing the small dust to greater distances where the gas is less abundant
A weak Ly
No full textThe abundant population of little red dots (LRDs), compact objects with red UV to optical colors and broad Balmer lines at high redshift, is revealing new insights into the properties of early active galactic nuclei (AGN). Perhaps the most surprising features of this population are the presence of Balmer absorption and ubiquitous strong Balmer breaks. Recent models link these features to an active supermassive black hole (SMBH) cocooned in very dense gas (NH ∼ 1024 cm−2). We present a stringent test of such models using VLT/MUSE observations of A2744-45924, the most luminous LRD known to date (LHα ≈ 1044 erg s−1), located behind the Abell-2744 lensing cluster at z = 4.464 (μ = 1.8). We detect a moderately extended Lyα nebula (h ≈ 5.7 pkpc), spatially offset from the point-like Hα seen by JWST by ≈1.6 pkpc. The Lyα emission is narrow (FWHM = 270 ± 15 km s−1), and faint (Lyα = 0.07Hα) compared to Lyα nebulae typically observed around quasars of similar luminosity. We detect compact N I