Institute of Physics and Technology

Abstract We present a photometric study of the interstellar comet 3I/ATLAS based on observations obtained between 2025 July 3 and September 22 from two observatories in Spain (Z10 and Y71) using small-aperture telescopes. The comet was monitored in five photometric bands ( CV, C, R, G , and B ), revealing an apparent brightness range from 19.10 to 13.50 mag. The observed variability reflects differences in observing site and filter bandpass, as well as significant scatter caused by background stellar contamination in crowded fields. Throughout the observing interval, comet 3I/ATLAS exhibited weak activity, with only a faint tail detected. A consistent brightening trend was measured in all filters, with average rates ranging from 0.033 to 0.066 magnitudes per day, indicating a progressive increase in activity. Measurements of coma size, tail length, and tail position angle were obtained for selected epochs. Derived Af ρ values suggest that comet 3I/ATLAS was undergoing a phase of increasing activity associated with its approach to perihelion.

P-cresol, indole and indole-3-acetic acid (IAA) are catabolites of amino acids, formed by the gut microbiome. Most of these aromatic hydrocarbon derivatives are excreted by the colon before reentering the body to form “exogenous” protein-bound uremic toxins (PBUTs), which aggravate chronic kidney disease (CKD). Removal efficiencies of these PBUT precursors from model phosphate-buffered saline solutions by three different surface-modified nanoporous carbon adsorbents (PCs) were studied. PCs were produced by physicochemical and/or acid base activation of carbonized rice husk waste. Removal rates achieved values of 32–96% within a 3 h contact time. High micro/mesoporosity and surface chemistry of the N- and P-doped biochars were established by N2 adsorption studies, SEM/EDS analysis, XPS and FT-IR-spectroscopy. The ammoxidized PC-N1 had the highest adsorption capacity (1.97 mmol/g for IAA, 2.43 mmol/g for p-cresol and 2.42 mmol/g for indole), followed by “urea-nitrified” PC-N2, whilst the phosphorylated PC-P demonstrated the lowest adsorption capacity for these solutes. These results do not correlate with the total pore volume values for PC-N2 (0.91 cm3/g) < PC-P (1.56 cm3/g) < PC-N1 (1.84 cm3/g), suggesting that other parameters such as the micropore volume (PC-N1 > PC-N2 > PC-P) and the interaction of surface chemical functional groups with the solutes play key roles in the adsorption mechanism. N-doped PC-N1 and PC-N2 have basic functional groups with higher affinity with acidic IAA and p-cresol. The ion-exchange mechanism of phenolic and indolic compound chemisorption by nanoporous carbon adsorbents, modified with surface N- and P-containing functional groups, has been proposed.

We re-derive an exact analytic three-parameter expressions for the non-rotating metric, describing a Taub-NUT-like black hole (BH), and its associated bumblebee field that are solutions to the Einstein-bumblebee gravity. We construct a consistence thermodynamics for the Taub-NUT-like BH and determine its thermodynamic topological class. The Lorentz symmetry breaking affects the mass and temperature of the BH but does not affect its thermodynamic topological classification.

The operational instability of perovskite solar cells (PSCs), particularly at realistically high temperatures of &gt;50 oC, remains a primary barrier to their commercialization. Methylammonium lead iodide (MAPbI3) is a prototypic...