Universitat Politècnica de Catalunya

Analysis of Tonga eruption-induced disturbances in the upper thermosphere based on atmospheric drag accelerations from LEO satellites

Abstract The violent eruption of the Tonga volcano on 15 January 2022 triggered significant disturbances in the atmosphere and ionosphere. However, limited observational capabilities have persistently hindered the characterization of eruption-induced neutral density disturbances...

Variability of Saturn's Equatorial Zonal Winds at Cloud Level Between 2018 and 2025

Abstract Saturn's zonal wind profile at cloud level has been measured at different epochs since the Voyager 1 and 2 in 1980–81. At most latitudes, zonal winds change little over time. However, the equatorial region, between planetographic latitudes 10°N and 10°S, presents a compl...

Surface roughness-driven inverse design of milling processes using machine learning

Interest in applying data-driven approaches in manufacturing has grown significantly, particularly for mapping complex, high-dimensional relationships. The milling process is one area where predictive models can link influential parameters to surface roughness metrics prior to in...

Assessing the Impact of Alkali Post-Deposition Treatment on the Surface Properties of High-Efficiency Kesterite Absorbers.

The performance of kesterite solar cells has steadily improved over the past five years, driven by advances in molecular precursor composition and processing. Inspired by their success in high-efficiency chalcopyrite devices, alkali-salt post-deposition treatments (PDTs) have bee...

Gas absorption of soft X-rays strongly impacts the redshift distribution of dark Fast X-ray Transients

Abstract The progenitors of many Fast X-ray Transients (FXTs) and those of γ-ray bursts (GRBs) are strongly linked. Given that ”dark” GRBs are typically found to be events suffering from enhanced extinction in the host galaxy, we investigate the nature of ”dark” FXTs. However, un...

Pneumococcal population structure influences the effects of air pollution on invasive disease risk in South Africa

Abstract Streptococcus pneumoniae is highly diverse, comprising over 100 serotypes and hundreds of genomic lineages amid widespread vaccination. While it can cause invasive pneumococcal disease (IPD) which exhibits pronounced seasonal spikes, the interplay between pneumococcal di...

Heights of complete intersections in toric varieties

The height of a toric variety and that of its hypersurfaces can be expressed in convex-analytic terms as an adelic sum of mixed integrals of their roof functions and duals of their Ronkin functions. Here we extend these results to the 2 -codimensional situation by presenting a li...

Modelling the simultaneous adsorption of two competing species

In this paper, we develop a mathematically consistent analytical framework to describe the simultaneous adsorption of two competing species in a packed column, accounting for adsorption, desorption and competitive replacement. Starting from previous work on the capture of a singl...

Protein Language Model Embeddings Recover Evolutionary and Functional Organization Across the Ras Superfamily

Abstract The Ras protein superfamily comprises small GTPases that share a conserved G-domain but differ in flanking regions, regulation, and cellular roles. Because existing classifications rely mainly on G-domain phylogeny, this superfamily provides a useful test case for assess...

Two-dimensional billiards are Turing complete

We show that two-dimensional billiard systems can simulate universal Turing machines. Billiards serve as idealized models of particle motion with elastic reflections and arise naturally as limits of smooth Hamiltonian systems under steep confining potentials, and as an exact refo...

Shedding light on the formation mechanisms of Islamic polychrome lusters: A Cu, Fe, Ag micro XANES study

Islamic luster is a ceramic glaze decoration exploiting the quantum-confined optical response of noble metallic nanoparticles to produce a colorful metallic and iridescent appearance. Upon firing, silver and copper initially present in an overpaint diffuse into the glaze and are...

Quantifying atmospheric and land drivers of hot temperature extremes through explainable Artificial Intelligence

Abstract. Different drivers have been shown to play a central role in modulating the occurrence and intensity of summer temperature extremes, yet their individual contributions remain difficult to quantify. In this study, we develop an explainable machine‐learning framework to di...

Characterization of diseases in temporal comorbidity networks

Comorbidity networks, or disease-disease networks, represent relationships between diseases and can reveal non-random disease associations and multimorbidity structure. These patterns reflect shared pathophysiology, diagnostic pathways, and risk of adverse outcomes. Using large-s...

Accessibility from a women's perspective: Assessing equitable walkable access across socioeconomic divides

This study evaluates female walkability as a means of accessing critical urban services in two contrasting neighborhoods in Uberlândia, Brazil: the peripheral and socioeconomically vulnerable settlement of Glória and the more central and affluent area of Santa Mônica/Segismundo P...

Mapping the nuclear environments of extreme coronal line emitting galaxies

Abstract Extreme coronal line emitters (ECLEs) are a rare class of galactic nuclei exhibiting unusually strong high-ionisation forbidden emission lines, and several ECLEs have been linked to tidal disruption events (TDEs). In this work, we compile and analyse optical spectra of 3...

Millimeter-wave UAV channel model with height-dependent path loss and shadowing in urban scenarios

Abstract Uncrewed aerial vehicles (UAVs) serving as aerial base stations (ABSs) are expected to extend 6G millimeter-Wave (mmWave) coverage and improve link reliability in urban areas. However, UAV-based air-to-ground channels are highly dependent on height and urban geometry. Th...

Copolymer Self-Assembly Triggered by Cis – Trans Polyproline Isomerization

Abstract Polyproline exists in two forms, the all-cis right-handed polyproline helix (type I) and the all-trans left-handed polyproline helix (type II). While the former is favored in common organic solvents, the latter is favored in aqueous solutions. Taking advantage of the hyd...

Poloxamer/HPMC/Carbopol-Based Thermosensitive Hydrogel Loaded with Ibuprofen for Potential Vaginal Drug Release

Vaginal drug delivery offers a critical route for local treatments but is limited by short formulation residence times. This study describes a thermosensitive in situ gel prepared by the cold-dissolution method from a ternary blend of Pluronic F127, Carbopol 940, and HPMC for loc...

Spurious Drifts in the ITCZ Location and Associated Atmospheric Circulation in Decadal Climate Predictions

Abstract Decadal predictions are affected by initialization shocks and drift, typically diagnosed in ocean circulation or temperature. It is not known, however, to what extent the drift can affect atmospheric dynamics. Here we investigate how the drift causes spatial shifts in th...

Perplexity as a metric for isoform diversity in the human transcriptome

-an interpretable measure derived from entropy-that quantifies the effective number of isoforms per gene based on the full, unfiltered isoform ratio distribution. Calculating perplexity for 124 ENCODE4 PacBio LRS datasets spanning 55 human cell types, we show that it provides int...