This letter presents a new passive sensor for temperature measurements based on a harmonic radio-frequency identification (RFID) tag that uses the temperature sensitivity of Schottky diodes as the main component for the generation of harmonics. The design of the harmonic sensor is based on the fact that the diode is a nonlinear device that when excited at one fundamental frequency generates harmonics of that signal. In this case, the generation mechanism is sensitive to temperature due to the diode thermal voltage variation with temperature. Measurements prove the performance of the sensor.

In order to assist in the screening and monitoring of possible infected by COVID-19, whose fever is one of the initial symptoms, a RFID tattoo tag for human monitoring was developed. The prototype of the tattoo tag presented proved to be effective in measuring human body temperature from 36° to 40° C, thus being a viable option for large-scale screening and analysis, and for being made with aluminum foil and school adhesive tape. That when using these materials, it presents itself as a disposable device, of low cost, durable, and operable in the RFID UHF frequency range.

The 5G wireless systems bring the new concept of the Internet of Everything, emerging trends that include new services and the recent revolution in smart wearable devices. In the systems for on-body applications, the antennas have been challenging because they are conventionally built on rigid substrates. However, embedding antennas into clothing allows expanding the interaction of the user with some electronic devices. This paper presents the design of a single patch and MIMO textile antennas, operating at 5.8 GHz. The performance of both textile antennas was tested and the reproducibility of the manufacturing technique was analyzed.

Este artigo apresenta uma abordagem sobre o uso de controle biológico aplicando a ação de bactérias contra Corynespora cassiicola (Bert & Curt) Wei pois este é um dos principais fitopatógenos de propagação aérea que limita a produtividade das solanáceas. A utilização de bactérias no controle de doenças em solanáceas é uma metodologia em difusão, pois o biocontrole de fitopatógenos realizado por bactérias pode ocorrer por diferentes mecanismos como a inibição por antibióticos, o parasitismo, a competição pelo espaço físico ou a indução de resistência da planta ao ataque de patógenos. Esta pesquisa visou selecionar, identificar e avaliar in vitro e in planta bactérias antagonistas com potencial para desenvolvimento de um bioproduto que contribua para o desenvolvimento agrícola sustentável de tomate. As coletas e os testes in planta foram realizadas na Estação Experimental de Hortaliças Dr. Alejo von Der Pahlen, KM 14 da estrada AM 010 (S: 02° 59’ 45,7” e W: 60° 01’ 22,3”). Os testes in vitro foram realizados na Embrapa Amazônia Ocidental. Os resultados indicam que o Bacillus amyloliquefaciens, apresentou 75,73% de inibição do C. cassiicola in vitro e 56% de controle da mancha-alvo quando comparado ao Microbacterium resistens e a Stenotrophomonas maltophilia nos testes em tomateiro.

Thermoformed tubular channels piezoelectrets exhibiting piezoelectric-magnetic behaviors were recently presented as Thermoformed Magnetic-Piezoelectrets (TMPs). This alternative sensor was suitable for detecting external magnetic fields from distant magnets. In this contribution, TMPs transducer was investigated as current transducer, where the magnetic field produced by an electrical current passing through a energized wire mechanically stimulates the TMP and consequently disrupts the electrical charge equilibrium providing a proportional electrical signal. The charge variation was correlated with the magnetic field intensity, providing a piezo-magnetic coefficient, similar to those noted in traditional piezoelectrets. It has been noticed that under certain conditions, TMP could have coefficients up to 498 × 10 ⁵ pC/T. From these results, it was concluded that such a polymer-based device is suitable for monitoring electrical current in live wires, providing an interesting solution for non-invasive current transducers (CT) with a reduced footprint. These novel transducers can thus provide an effective replacement for coil-based CTs reducing installation cost and space, without the need for wire re-connection (as required by the coil CTs), enabling hot-plug capabilities, as well as providing a direct and cost-effective replacement for high-frequency current transformers.

The main goal of this paper is to validate an experimental methodology and investigate the shield quality of RG-58 coaxial cables and connectors versus coaxial cable and connectors with total shielding for VHF/UHF band, from 100 MHz to 400 MHz. The experimental analysis reveals an important difference between the two sets of cables and connectors. A computational simulation was carried out with emphasis on validating the measurement of the resonance frequencies of the set used in the test. The electric field radiated by the RG-58 cable and connectors at 300 MHz, the ressonance frequency of the set, is 2.27 V/m. It can also be noticed that there is almost no electric field radiated by the CELLFLEX coaxial cable and connectors in this frequency, the level is 0,74 V/m which is close to the noise floor of the semi anechoic chamber.