The top-quark Yukawa coupling is extracted from the distribution of the top-quark pair ( tt ) invariant mass in proton-proton collisions using 140 fb−1 of data at √(s)=13 TeV collected in 2015–2018 by the ATLAS experiment at the Large Hadron Collider. In the region near the production threshold, the tt invariant mass spectrum is sensitive to electroweak virtual corrections, including contributions from Higgs boson exchange, thereby providing sensitivity to the top-quark Yukawa coupling. This is the first measurement in ATLAS that aims to obtain this coupling exploiting this approach. The tt system is reconstructed in the single-lepton final state, requiring exactly one isolated electron or muon and at least four jets with at least two identified as originating from b-quarks. The measured Yukawa coupling is found to be in good agreement with the Standard Model prediction. An upper limit on the top-quark Yukawa coupling strength of Yt < 2.1 relative to the Standard Model prediction is observed at 95
Flexible electrode materials with tailored electrical and mechanical properties are essential for reliable electrocardiographic (ECG) sensing. In this work, p-toluenesulfonic-acid-doped polypyrrole (PPy-TSA) films were modified using polymeric and inorganic fillers, as well as their combinations (polyethylene glycol, graphene, carbon nanotubes, and zeolite), to tune their functional performance. The reference PPy-TSA film exhibits typical morphological and chemical characteristics of doped polypyrrole and serves as a reliable baseline for comparison. All composite films retain electrical conductivity within the range required for ECG applications while showing improved mechanical compliance (i.e., enhanced ability to conform to the skin and sustain deformation). Based on the optimized balance between electrical and mechanical properties, flexible ECG electrodes were fabricated using the TSA-doped PPy-based composite film. ECG recordings obtained with the several proposed electrodes show good agreement with those acquired using a commercial ECG electrode, demonstrating the potential of PPy-based composite films for flexible bioelectronic sensing applications.
Fe–acceptor doping of Ba 0.82 Ca 0.18 Zr 0.08 Ti 0.92 O 3 piezoceramics induces defect complexes, which dramatically improve the hard-type piezoelectric properties only after extensive room temperature aging.
In this work, the chemical solution deposition (CSD) technique has been employed for the first time to grow europium-doped gadolinium oxide (Gd2O3:Eu3+) epitaxial thin films on (100)-oriented MgO substrates. The influence of Eu3+ doping levels (1, 2.5, 5 at.%) on the structural, morphological, and optical properties of the films was systematically investigated. Thermal decomposition of the chemical precursors was examined using thermogravimetric analysis (TG-DTA) coupled with mass spectrometry (MS). Fourier transform infra-red (FTIR) spectroscopy was employed to track ligand removal, while phase formation and crystallinity were confirmed by X-ray diffraction (XRD), showing the formation of epitaxial cubic Gd2O3. Atomic force microscopy (AFM) revealed changes in surface morphology and roughness with increasing Eu content. Optical band gaps and Urbach energies were determined via ultraviolet-visible (UV-Vis) spectroscopy, indicating changes in electronic disorder with doping. X-ray photoelectron spectroscopy (XPS) confirmed the Eu3+ incorporation and stoichiometry of the films, with depth profiling showing dopant apparent concentration maximum detected after sputtering. Photoluminescence (PL) measurements demonstrated efficient red emission under UV excitation, primarily from the 5D0-7F2 transition of Eu3+. This represents the first report of epitaxial growth by CSD of undoped or Eu3+-doped Gd2O3 two-dimensional systems demonstrating the versatility of this compositionally tunable synthetic approach.
Phase change materials (PCMs) have emerged as an innovative solution in thermal energy storage and thermal management systems (TMS) owing to their outstanding latent heat of fusion during the phase change process. This study is especially addressed to the battery TMS based on Organic PCMs for fast charging/discharging applications of lithium-ion batteries (LIBs). These fast processes generate excessive heat during operation, degrade battery performance, decrease energy efficiency, and reduce the lifespan and safety of batteries. Organic PCMs exhibit desirable properties, including high latent heat capacity, good thermal characteristics, low cost, and ease of integration. The major challenge for the successful application of organic PCM comprises its low thermal conductivity, which impacts the heat storage and release rates. PCM-based Paraffin Wax (PW) has been designed by including expanded graphite (EG) as a high thermal conductivity additive in high latent heat of paraffin wax. Experiments focused on the effects of heating methods (microwaves/S-type EG composition and conventional electric oven/S′-type EG composition) of expandable graphite on the thermophysical properties of different PW/EG composites. The crystal and chemical structure of the study samples were analyzed by X-ray diffraction and Fourier-Transform Infrared spectroscopy. The battery module created with PW/EG composites were ample examined using charging/discharging experiments at five different C-rates. The effect of current rates on battery surface temperature is investigated in two cases: with PCM cooling and with air cooling. A 20.43% decrease in battery temperature is found at 5C rate with PCM cooling and a maximum reduction in battery charging time of 43.77%.
