The National Institute of Metrology, Quality and Technology (Instituto Nacional de Metrologia, Qualidade e Tecnologia - INMETRO) introduces that, starting in 2024, all photovoltaic (PV) inverters sold in the Brazilian market must incorporate an Arc-Fault Circuit Interrupt (AFCI) function into their systems. These inverters are required to comply with the IEC 63027:2023 (Photovoltaic power systems DC arc detection and interruption) standard. Considering this, the Electrical Engineering Laboratory at Mackenzie Presbyterian University (Universidade Presbiteriana Mackenzie UPM) conducted a series of arc-faults tests on three inverters available in the market, following the IEC 63027 standard. Each of the three inverters underwent a total of 32 arcs, considering number of Maximum Power Point Tracking (MPPT) ports, different impedance topologies, arc position in the PV system, and maximum values of voltage and current. The experiments revealed that two of the three inverters are not capable of meeting the international standard for detecting and interrupting series arc-faults, highlighting the need evaluation of PV inverter sold in the Brazilian market. During the analysis, it was noted that for certain parameters proposed by IEC 63027, there is a gap of information regarding evaluation of the data relating to arc self-extinguish or actual AFCI intervention. It is show that this scenario can raise a concern: the possibility exists for an inverter meet the international standard without implementing an effective AFCI technology. The 96 tests conducted were compared in terms of arc detection time and arc energy. The data were analyzed and compared with respect to the phenomena of arc self-extinguishing and the operation of the AFCI. Suggestions for enhancements to the IEC 63027 standard were provided

In cases of severe injuries or burns, skin grafts (scaffold) are often necessary skin substitutes. To not harm the patient or the donor, research is necessary to search for heterografts, that are formed by biomaterials and are also biodegradable and bioabsorbable to the human body, as is the case with poly (L-lactic acid) - PLA. However, the natural polymers placed on the skin suffer great degradation in media with large amounts of carbon and water, have little durability due to their low ductility. For the proposal, the graphene oxide (GO) nanocharge and pseudoboehmite (PB) were obtained. It is believed that the nanofillers dispersed in the polymer matrix can improve mechanical properties regarding ductility and tenacity, without losing thermal properties. Subsequently, the hybrid nanocharge dispersion methods were employed to obtain in the poly (L-Lactic Acid) (PLA) matrix, forming the material for the desired scaffold. For this research, injectable specimens of pure PLA, PLA structured with GO nanoparticles, and PLA structured with PB nanoparticles, were manufactured. The microstructural and mechanical characterizations were performed on the specimens, to compare the effect generated by the nanocharges on the bulk material. The results showed that the increase in the concentrations of PB and GO nanofillers showed an increase in tenacity and ductility compared to pure PLA, a property that is desired in the scaffold structure.

In cases of severe injuries or burns, skin grafts (scaffolds) are often required as skin substitutes. In order not to harm the patient or the donor, biodegradable and biocompatible materials are used, which validates the search for heterografts such as poly (L-lactic acid)—PLA. However, natural polymers applied to the skin suffer great degradation in environments with large amounts of carbon and water or via binders with considerable resistivity, which implies little durability due to their low ductility. For the proposal, this work investigates PLA-based scaffolds modified with a mixture of pseudoboehmite (PB) and graphene oxide (GO), produced via the sol–gel route. The nanomaterials are incorporated into the polymer at different loadings, seeking to improve mechanical and thermal properties. Analyses via SEM, EDS, and XRD confirm the presence and distribution of these fillers. Tensile and flexural tests indicate that adding the filler can increase stress resistance, prevent deformations before failure, and increase toughness when compared to pure PLA.

In this work, a methodology based on the finite element method is proposed for the design and simulation of optical modulators that exploit the magnetostrictive effect, aimed at enhancing the performance of magnetometers. The study focuses on a channel-type optical waveguide whose cross-section is carefully engineered to maximize opto-mechanical interaction while ensuring straightforward integration with magnetostrictive thin films. Fabrication follows the Induced Static Stress (ISS) technique: sputter deposition of a Terfenol-D (Tb_0.3Dy_0.7Fe_1.92) layer onto a bismuth germanium oxide (Bi₁₂GeO₄) substrate creates residual stresses because of mismatched thermal expansion coefficients. During operation, applied magnetic fields induce magnetostrictive deformation, which, together with the pre-existing thermal stresses, modifies the local refractive index via the elasto-optic effect, thereby enabling dynamic guiding and modulation of guided light. Numerical analysis is carried out in COMSOL Multiphysics 5.6, employing coupled structural and optical modules. A fine mesh is generated along the waveguide core, while material parameters such as Young’s modulus, Poisson’s ratio, magnetostriction constant, and refractive indices are specified for each layer.