No abstract

No abstract

The learning of phenomena related to electromagnetic waves develops in an evident way when students are stimulated significantly and, one of the possible ways are contextualized experimental practices. In this way, a system was developed that allows the sending and reception of electromagnetic waves, which can be provided by a signal generator or by a transmitting radio. For the implementation of the system, two Yagi-Uda antennas were built, intended for the transmission and reception of signals; for the emission of signals a low-power transmitter radio and for the measurement of the intensity of the received signals, a signal intensity meter was constructed from a multimeter in which a circuit was added that converts the signals received into direct current proportional to their intensity. The system was used in the physics discipline of high school, where it was observed that using this system, the students presented a better understanding of the phenomena related to electromagnetic waves.

This article presents a methodology for two-dimensional modeling of the human eye to analyze the heat transfer in biological tissues, in this case, ocular tissues. The technique used was the finite differences method in the time domain. With a proposal for a numerical simulation of the problem, see that this type of work aims to promote the development of tools that help detect errors in biomedical engineering. Several medical procedures, including surgical ones that use laser, whose main limiting factor is the increase in temperature in living tissue, a fact that can cause irreversible damage, even evaporating. For example, refractive eye surgery using a laser. The simulation is intended to calculate the temperature gradient to guide the physician more precisely before an intervention. An example of this is certain types of inoperable tumors that can be irradiated with laser sources. Their function is to cause a rise in local temperature to destroy cancer cells without thermal damage to the healthy region.

This work presents the development and implementation of a System for Acquisition of Rotations composed of an open-source Arduino electronic prototyping platform and a Supervision and Data Acquisition System (SCADA). This system obtains instantaneous values for frequency, linear velocity, and angular velocity, and the graphical representation of said instantaneous values is in real-time. Thus, the proposed system is a mediator of learning for the teaching of Circular Movement Uniform, with theoretical/practical interaction essential in classes for understanding the content.

The present study aimed to obtain alcoholic and hydroalcoholic (70% v/v) extract of Syzygium malaccense (L.) Merr. & L. M. Perry (red jambo fruit tree) leaves and investigated the influence of temperature and time of exposure to temperature on the extraction yield. It was applied a 2x2 factorial design, considering temperature and time of exposure as independent variables with two levels each: 30 or 60 °C for temperature and 60 or 120 minutes for time. For both ethanolic and hydroethanolic extraction, higher process yields were observed at higher temperature and time (24.26% and 19.00%, respectively), however, no significant difference was noticed when increasing the time of exposure to temperature.