This study examined injuries sustained by a six-year-old child dummy in a numerical dolly rollover crash using a Toyota Yaris 2010. A harmonic dynamic system (HDS) composed of spring, dampers, and masses with a Low Back Booster (LBB) is denominated as HDS-LBB model. The HDS-LBB was designed to allow damping movements along three Cartesian axes (X, Y, Z) to reduce the energy transferred to the child by a motor vehicle accident and avoid a high injury risk. The HDS-LBB incorporates springs into the vertical axis to decrease the vertical movement during the rollover. The numerical analysis was conducted using LS-Dyna® R12.1 version during an interval of 1 s, and the boundary conditions were set by the Federal Motor Vehicle Safety Standard (FMVSS) 213 for child restraint recommendations and the FMVSS 208 for a dolly rollover procedure. Data on head and thorax decelerations, neck flexion-extension, and thoracic deflection were acquired at a rate of 1 ms. The injury values obtained by the HDS-LBB were compared with the injury values by another configuration denominated LBB-ISOFIX to assess the effectiveness of the model proposed. The results show a higher peak injury value in the neck and thorax because of seatbelt displacement across the child’s shoulder. Nevertheless, despite this seatbelt behavior, the injuries sustained remained below the Injury Assessment Reference Values (IARVS).

Polypyrrole (PPy) synthesized via plasma polymerization (PPPy) offers a unique combination of electrical conductivity, biocompatibility and stability. This advanced material has emerged as a promising platform for next-generation optoelectronics and multiphotonic biosensors. However, fully unlocking its potential has been hindered by processing challenges that restrict the fabrication of tailored specimens for precise optical and mechanical characterization. This work overcomes these limitations by isolating and analyzing the nonlinear optical (NLO) response of PPPy across three distinct architectural paradigms: Electrospinning, Coating on SiO₂ Slides, and Dust of Polymer. Using open- and closed-aperture Z-scan techniques, we demonstrate that PPPy exhibits highly pronounced, architecture-dependent NLO behaviors. Notably, the Electrospinning PPPy morphology triggered a full order-of-magnitude enhancement in the nonlinear refractive index (n₂) alongside low-threshold nonlinear absorption (β × 10⁻⁸ cm/W). Irradiance-dependent properties further revealed an optical anisotropy, directly governed by the structural and morphological orientation inherent to each processing method. Since optical nonlinearities are closely related to mechanical and electronic properties, these findings provide a critical blueprint for developing macromolecular architectures, opening new pathways for biocompatible cutting-edge multiphotonic platforms, innovative coatings and surface modifications for tailored implants.

Martial arts have evolved from self-defense practices into structured competitive sports that demand high levels of neuromotor control, where improper execution remains a major source of injury. This study evaluates lower-limb control during the execution of the karate lateral kick using videogrammetry biomechanical analysis. Three participants were recorded during regular training sessions and selected according to their level of expertise. Each participant performed lateral kicks at three predefined distances (close, comfortable, and long), selected based on common training practice and individual biomechanical considerations. Videogrammetry data were generated using Kinovea version 0.9.5 software to extract sagittal ankle trajectories. Statistical analyses were carried out in MATLAB version 2025b using spatial coordinates to obtain kinematic data on the practitioner’s performance. The results revealed skill-dependent differences in movement control, characterized by temporal evolution of kinematic variables and their corresponding time–frequency representations. Novice practitioners exhibited limited control during the raising and recovery phases, despite reaching the target. In contrast, expert practitioners demonstrated consistent posture, controlled acceleration during impact, and stable limb trajectories during descent. These observations provide a foundation for data-driven classification of kick execution quality and outline potential applications in supervised learning, real-time feedback systems, and injury risk reduction during karate training.

Some common conductive polymers are polyfuran, polyacetylene, polythiophene, and poly-pyrrole. Since their discovery, many researchers have been exploring and evaluating their conductive and electronic properties. Various applications have been developed for conductive materials. Their biocompatibility offers a new alternative for studying and solving complex problems, such as cellular activity, or, more recently, for use as neural implants and as an alternative to spinal cord regenerative tissue. This is particularly true for the use of poly pyrrole. The main obstacle lies in estimating some of the mechanical properties, such as Young’s or shear modulus values for poly pyrrole, since these vary depending on the type of synthesis used. This article outlines a composite methodology for characterizing the elastic modulus according to ASTM D882 and the shear modulus according to E143 standards. It is specifically designed and applied for 3D composite samples involving PLA and PPy, where the PPy was processed by plasma oxidation. As a result, an increase of 360.11 MPa in the modulus of elasticity is observed on samples coated with poly pyrrole. The results are evaluated through a numerical test using COMSOL Multiphysics software 6.2 version, finding a similar behavior in the elastic zone, as indicated by the stress–strain diagram. The statistical analysis yields consistent data for tensile and shear results, with low to moderate variability.

This document provides a design description of a data acquisition device that allows an alert to be issued to suggest to the driver to take a break after having subjected his body to a certain amount of acceleration and pressure changes after driving on a road with too many curves. The tests were carried out using sensors based on microelectromechanical systems. The system was strategically installed at specific points on the body of the driver and car. Several electronic arrays were carried out, like the design of a printed circuit board. The establishment of an inter-integrated circuit communication and its multiplexing to work with several devices with the same address simultaneously. Finally, in this context, the document also presents the critical velocity for each curve in the Hakone roadway, which was obtained by using a mathematical model and contrasted with data acquisition values for acceleration. The risk of skidding on a curve increases when the driver does not reduce driving velocity; only a slight variance in acceleration or environmental conditions is enough. The value of acceleration was acquired for the analysis of each curve; there is a greater possibility of skidding in curves 2 and 4 because their radius is smaller and the critical speed is approximately 60 km/h, which is very close to the driving speed. On the other hand, the deceleration value of −0.65 G read on the head accelerometer can increase fatigue symptoms such as blurry vision or dizziness.