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Gas motion in the intracluster medium of the Virgo cluster replica
No full textWithin the deep gravitational potential of galaxy clusters lies the intracluster medium (ICM). At the first order, it is considered to be at hydrostatic equilibrium within the potential well. However, evidence is growing on the observational side and in numerical simulations that the ICM dynamics is non-negligible from an energetic point of view, is mostly turbulent in origin, and provides non-thermal pressure support to the equilibrium. In this work, we intend to characterise the properties of the velocity field in the ICM of a simulated replica of the Virgo cluster. We first studied the 3D and projected properties of the ICM velocity field by computing its probability density functions (PDFs) and its statistical moments. We then estimated the non-thermal pressure fraction from an effective turbulent Mach number, including the velocity dispersion. We finally computed the velocity structure function (VSF) from projected maps of the sightline velocity. In this paper, we first show that the components of the 3D velocity field and the projected quantities along equivalent sightlines are anisotropic and affected by the accretion of gas from filaments. Then, we compare the mean statistical moments of the 3D velocity field to the mean properties of 100 random projections. We show, in particular, an almost linear relation between the standard deviation estimated from direct simulation outputs and sightline velocity dispersion projections, which are comparable to the line broadening of X-ray atomic lines. However, this linear relation does not hold between the direct simulation outputs and the standard deviation of the sightline velocity projections, which are comparable to the line shift of X-ray atomic lines. We find a non-thermal pressure fraction of around 6% within R_500 and 9% within R_vir from sightline velocity dispersion, which is in good agreement with direct simulation outputs. Finally, we show that the VSF might probe the turbulent injection scale of active galactic nucleus (AGN) feedback
Factors driving higher opioid use after total hip arthroplasty: Insights from a large-scale, tertiary centre analysis
No full textIntroduction: Effective postoperative pain management is imperative in total hip arthroplasty (THA) to enable early mobilization and accelerate recovery pathways. This study investigated the patterns of inpatient opioid consumption following THA and identified the factors associated with increased opioid usage. Methods: In this large-scale, single-institution study, we analyzed data from 1,867 primary THAs between April 2019 and July 2023. We collected data on demographics, length of stay (LOS), type of anaesthesia, Post Anaesthesia Care Unit (PACU) admissions, 30-day readmissions, total opioid consumption (MME; morphine milligram equivalents), implant fixation techniques, surgical characteristics and pre- and postoperative haemoglobin (Hb) levels. Factors associated with increased opioid consumption (patients in the ≥ 75th percentile of inpatient opioid consumption; MME ≥ 211.9 mg) were identified through univariate and multivariate logistic regression models. Results: The cohort included 1150 women (61.6%) and 717 men (38.4%). The median inpatient opioid use was 88 mg (IQR = 39.3–211.9). In the univariate model, significant predictors included age, American Society of Anaesthesiologists (ASA) score, manual THA technique, general anaesthesia, pre- and postoperative Hb levels, need for PACU admission and year of surgery. After adjusting for baseline demographics in the hierarchical multivariate logistic regression model, significant predictors of higher opioid utilization were age (OR 0.989 [95% CI 0.981–0.997], p = 0.01), general anaesthesia (OR 2.386 [95% CI 1.865–3.054], p < 0.001), PACU admission (OR 2.098 [95% CI 1.310–3.358], p = 0.002), ASA score (OR 1.492 [95% CI 1.193–1.866], p < 0.001), postoperative Hb levels (OR 0.981 [95% CI 0.970–0.992], p < 0.001), and year of surgery (OR 0.638 [95% CI 0.579–0.703], p < 0.001) indicating that later years were associated with lower odds of high opioid consumption). Discussion: Younger age, higher ASA scores, lower postoperative haemoglobin, the need for PACU admission and general anaesthesia were significantly associated with increased opioid consumption following THA. Recognizing these factors can facilitate the development of tailored postoperative pain management protocols, enabling targeted interventions that minimize opioid reliance while enhancing recovery
Stability and Bifurcation in an Age-Structured Predator-Prey System with Beddington-DeAngelis Response, Constant Prey Harvesting, and Two Delays
No full textThis work investigates the long-term dynamics of a novel predator-prey system that explicitly accounts for age structure, Beddington-DeAngelis functional response, constant-yield prey harvesting, and two distinct time delays. The first delay, \tau_1 denotes the predator's maturation period; the second, \tau_2 reflects the gestation delay between prey consumption and predator reproduction. Firstly, we recast the system into an abstract non-densely defined Cauchy problem. Then the existence of solutions and the uniqueness of positive equilibrium are discussed. By analyzing the distribution of the corresponding eigenvalues, the rigorous establishment of asymptotic stability for the boundary equilibria are achieved. We further present a detailed Hopf bifurcation analysis that simultaneously incorporates both time-delay parameters, employing stability-switching curves to clarify how varying delays reshape the system's dynamic behavior. Lastly, the practical implications of these theoretical findings are demonstrated through several numerical examples
Characterization of subsurface damage in fused silica using non-destructive optical coherence tomography and a destructive approach by iterative plasma jet etching
No full textIn this work, a Vickers indenter was used to systematically produce defined and artificial indentations on the surface of fused silica glass to systematically study subsurface damage (SSD). Various measurement methods, such as optical microscopy, white light interferometry (WLI) and optical coherence tomography (OCT), were used to examine SSD depths and morphol-ogies. Tomographic OCT measurements were performed to non-destructively characterize the defects. SSD depths were val-idated with a destructive preparation method using iterative plasma jet etching (PJE) and subsequent topography measure-ments with WLI. A total of eight PJE steps were performed to successively remove material, opening and widening surface and subsurface defects. SSD depths in this destructive characterization approach were deduced by combining the PJE etch-ing depth and the corresponding surface roughness parameter Sv.
Additionally, measurement methods were verified twice through OCT measurements performed after different etching steps. The increased surface roughness from PJE reduced OCT imaging artifacts and improved the OCT measurement accuracy. The final SSD depth, determined by adding the OCT-measured SSD values after PJE process to the respective PJE etching depth, was highly reliable. The SSD depth of the Vickers indentation determined by the combined use of OCT and PJE showed excellent agreement with the SSD depth estimated using a commonly applied empirical formula for Vickers indenta-tions, providing additional confirmation of the SSD depth and further demonstrated the robustness of the combined OCT-PJE approach
Practices and perspectives on the use of pesticides for post-harvest grain storage: evidence from Southeast Mexico
No full textThe issues surrounding the use of pesticides in food production prior to harvesting, are widely covered in the literature. Those relating to post-harvest practices are much less so, even though they are essential for food security and for the health of agricultural workers. In this study, we analyze the practices of small-scale farmers in Southeastern Mexico when storing maize grain, and examine their use of a reference insecticide, aluminum phosphide. We assess the reasons why farmers choose this technology, their sources of information, and their perceptions of the associated risks. The results show that practices vary in terms of doses used, application methods, exposure time, combination with other products, and grain cleaning after application. This variability results from a drastic lack of information available in rural communities regarding the correct use of pesticides. This lack is a consequence of a marketing system that is largely based on retail sales, with no instructions for use on packaging, and on village grocery sellers who are unaware of good practices and potential risks. Farmers systematically minimize the risks associated with pesticides, and believe they are protected from toxic side effects. These results suggest that rural development policies should focus on training farmers and input retailers, and on promoting alternative grain storage technologies
Evolution of the infrared luminosity function and its corresponding dust-obscured star formation rate density out to
No full textWe present a new determination of the evolving far-infrared (FIR) galaxy luminosity function (LF) and the resulting inferred evolution of dust-obscured star-formation rate density (ρSFR) out to redshift z ∼ 6. To establish the evolving comoving number density of FIR-bright objects, we made use of AS2UDS, a high-resolution ALMA follow-up study of the JCMT SCUBA-2 Cosmology Legacy Survey (S2CLS) submilliter imaging in the UKIDSS UDS survey field. In order to estimate the contributions of faint and low-mass sources, we implemented a method in which the faint-end of the IR LF is inferred by stacking (in stellar mass and redshift bins) the optical and near-infrared samples of star-forming galaxies into the appropriate FIR Herschel and submillimeter JCMT maps. Using this information we determined the faint-end slope of the FIR LF in two intermediate redshift bins (where it can be robustly established) and then adopted this result at all other redshifts. The evolution of the characteristic luminosity of the galaxy FIR LF, L★, is found to increase monotonically with redshift, evolving as L★ ∝ z1.38 ± 0.07, while the characteristic number density, Φ★, is well fit by a double power-law function; it is constant at z 4, and dust-obscured activity contributes less than 25% to the star formation rate density by z ∼ 6
New self-consistent theoretical descriptions for mass-loss rates of O-type stars
No full textMassive O-type stars lose a significant fraction of their mass through radiation-driven winds, a process that critically shapes their evolution and feedback into the interstellar medium. Accurate predictions of mass-loss rates ( are essential for models of stellar structure and population synthesis.
We computed wind parameters for O-type stars using a self-consistent approach that couples the hydrodynamics of the wind with detailed calculations of the line acceleration. This approach follows the theory of radiation-driven stellar winds and, thus, allows us to derive mass-loss rate distributions for different atomic configurations of the stellar flux.
We used the code for stellar atmosphere models to compute tailored non-local thermodynamic equilibrium models; these models served as input radiation fields for the calculation of the force multiplier factor and the line-force parameters, for which we used the code. These line-force parameters were then iteratively coupled with the code to solve the wind hydrodynamics. The procedure was repeated until convergence and applied across a grid of stellar parameters for three chemical configurations. tlusty locus hydwind
We obtain self-consistent wind parameters for a broad set of O-type stellar models. The results show a systematic decrease in mass-loss rates with the inclusion of more elements in the radiation field, which is attributed to a strong effect on the UV region of the spectral energy distribution. As more elements are included, resulting in a larger number of spectral lines, the contribution from the UV diminishes, leading to lower mass-loss rates. We fitted three theoretical prescriptions for using a Bayesian approach; this yielded Pearson correlation values greater than 0.92 for all three model grids. It also allowed for the estimation of the wind momentum-luminosity relationships for each of the grids, yielding results similar to those based on observations of O-type stars
Homogeneous abundances of Mg, Si, Ca, and Ti for about 1500 red giants in 16 globular clusters from FLAMES spectra
No full textThe FLAMES survey 'Na-O anti-correlation and HB' uncovered the modern standard for globular clusters (GCs), which is their ubiquitous multiple stellar populations (MPs) distinguished by the abundance of proton-capture elements. That survey can still be mined to extract a wealth of data. We derive new abundances of Mg, Si, Ca, and Ti for 948, 954, 1542, and 1350 red giant branch stars in 16 GCs, both formed in situ or accreted in the Milky Way. The programme GCs cover the metallicity range from Fe/H =-2.35 dex to Fe/H =-0.74 dex. Both the halo and disc GCs show a clear overabundance of α-elements with the modulation in Mg and Si due to the MPs phenomenon in different clusters. We found star to star variations in Si abundance correlated to changes in Na in more than half our sample, implying that temperatures in excess of about 65 MK were achieved in the polluters responsible for the enrichment. We confirm with an enlarged sample the previous result that significant variations in Mg are observed in GCs that are metal-poor, massive or both. Evidence of excess of Ca with respect to reference unpolluted field stars are found in NGC 6752 and NGC 7078, indicating the action of proton-capture reactions at very high temperature regime in these GCs. These excesses fit very well in a previously found relation as a function of a combination of cluster mass and metallicity shown by other typical signatures of MPs. At odds with previous results based on the Si abundance from APOGEE, we found that the average abundance of α-elements is not an efficient discriminating factor between in situ and accreted GCs
Tailoring photocatalytic performance of spin-Coated BiVO
No full textWater pollution from synthetic dyes, particularly the toxic and non-biodegradable Rhodamine B (RhB), has spurred the development of efficient semiconductor-based photocatalytic technologies. Bismuth vanadate (BiVO₄), with a band gap of ~2.3–2.4 eV, is a promising visible-light-responsive photocatalyst. In this work, BiVO₄ thin films were fabricated on FTO substrates via spin coating, followed by calcination at 500 °C for varying durations (5, 10, 15, 20, and 25 min). The structural, morphological, and optical properties were characterized using XRD, SEM-EDX, UV-Vis DRS, and photoluminescence (PL) spectroscopy. Characterization confirmed the formation of monoclinic BiVO₄ with high crystallinity, a uniform surface morphology, and an optimal distribution of Bi and V elements. The optical band gap decreased from 2.30 eV (5 min) to 2.23 eV (15 min), enhancing visible-light absorption. PL spectra indicated reduced emission intensity for the 15 min sample, suggesting improved charge-separation efficiency. Photocatalytic experiments demonstrated that the 15 min calcined BiVO₄ achieved the highest photocurrent density (90 µA/cm2) and an RhB degradation efficiency of 85.96% within 100 min, following pseudo-first-order kinetics. These results highlight that spin-coated BiVO₄ thin films with optimised calcination time exhibit superior structural, optical, and photoelectrochemical properties, making them promising candidates for visible-light-driven wastewater remediation
Synthesis, characterization, and application of Fe₃O₄/PEG/HAp nanocomposite as an adsorbent for Pb(II)
No full textThis study presents the synthesis, characterization, and adsorption performance of a Fe₃O₄/PEG/HAp nanocomposite developed for the efficient removal of Pb2⁺ ions from aqueous solutions. The composite was fabricated through a co-precipitation and wet chemical method by integrating magnetite (Fe₃O₄), polyethylene glycol (PEG), and hydroxyapatite (HAp) to achieve a synergistic combination of magnetic recoverability, surface functionality, and structural stability. FTIR analysis confirmed the presence of Fe–O, PO₄3⁻, and C– O–C functional groups, verifying strong interfacial interactions among the components through coordination and hydrogen bonding. Adsorption experiments demonstrated optimal performance at a contact time of 12 hours, temperature of 25 °C, and adsorbent dosage of 0.1 g. The adsorption capacity decreased at elevated temperatures due to partial desorption and weakened electrostatic attraction, while higher adsorbent mass caused site overlapping and reduced surface efficiency. Kinetic data fitted well with the pseudo-second-order model (R2 = 0.9997), indicating chemisorption as the dominant mechanism. Thermodynamic parameters (ΔH° = 100.43 kJ mol⁻1, ΔS° = −3310 J mol⁻1 K-1) revealed an endothermic yet spontaneous process with decreased entropy at the solid–liquid interface. The Fe₃O₄/PEG/HAp nanocomposite showed excellent magnetic separability and reusability, retaining over 90 % of its adsorption capacity after multiple cycles. These findings highlight its potential as an eco-friendly, regenerable, and efficient adsorbent for Pb2⁺ removal