Drying is a thermodynamic process in which the moisture contained in the solid is removed by evaporation through the supply of an appreciable amount of thermal energy. It is recognized as a critical and intricate stage in the manufacturing process of ceramic materials. In general, drying at higher temperatures and lower air-relative humidity provokes severe hydric, thermal, and mechanical fractures in the ceramic parts, thus reducing product quality after the process. Then, this process must be realized under controlled conditions. From an industrial point of view, the drying process of sanitary ware takes place in two stages: drying at low temperatures (less than 40 °C) and drying at high temperatures (above 50 °C). Thus, the purpose of this work is to experimentally investigate the drying process at low temperatures in sanitary toilets. Drying experiments were conducted in an oven with the same temperature (35 °C) and different relative humidity of the drying air. The results of the moisture content, temperature, and dimension variations along the process, as well as drying and heating rates, are reported and analyzed. The results indicate that the higher the air’s relative humidity, the slower the moisture removal. Herein, aspects of the product quality after the drying process are also discussed.

Drying is one of the stages with the highest energy consumption in the manufacturing process of ceramic materials and aims to reduce the product’s moisture to levels necessary for safe firing stage, reducing the chances of defect formation. For sanitary ware, there is an additional energy cost in the pre-drying stage, which takes place immediately after removing the parts from the molds, and is carried out in an environment with lower temperatures (ranging from 30 to 40 °C). This work aims to experimentally study the drying process of sanitary ware at low temperatures, with particular reference to sanitary toilets with industrial dimensions. Four drying experiments were carried out in an oven with different operating conditions (temperature and relative humidity). The results indicate that an increase in temperature and reduction in relative humidity provoke a faster drying rate. For some physical situations, it is more interesting to dedicate efforts to reducing the relative humidity of the drying air instead of seeking solutions to raise its temperature. Furthermore, a correlation between the linear retraction and moisture content was observed; the greater the moisture loss, the greater the sample shrinkage.

A conventional hydrocyclones is a versatile equipment with a high processing capacity and low maintenance cost. Currently, several studies aim to alter the typical structure of the conventional hydrocyclone in order to modify its performance and purpose. For this, filtering hydrocyclones have emerged, where a porous membrane replaces the conic or cylindrical wall. During the operation of this equipment, in addition to the traditionally observed streams (feed, underflow, and overflow), there is a liquid stream resulting from the filtration process, commonly referred to as filtrate. This work proposes to numerically investigate the solid particle/liquid water separation process in a filtering hydrocyclone using the commercial software Ansys CFX^® 15.0. The proposed mathematical model for the study considers three-dimensional, steady state and turbulent flow, using the Eulerian–Eulerian approach and the Shear Stress Transport (SST) turbulence model. This study presents and analyzes the volume fraction, velocity, and pressure fields, along with flowlines and velocity profiles. The results indicate that the proposed model effectively captures the fluid dynamic behavior within the filtering hydrocyclone, highlighting higher pressures near the porous membrane and a higher concentration of solid particles in the conical region, with water being more concentrated in the cylindrical part of the hydrocyclone. Additionally, the findings show that the volumetric flow rate of the filtrate significantly influences the internal flow dynamics, with conventional hydrocyclones demonstrating higher pressure gradients compared to the proposed filtering hydrocyclone.

Resin Transfer Molding (RTM) is a widely used composite manufacturing process where liquid resin is injected into a closed mold filled with a fibrous preform. By applying this process, large pieces with complex shapes can be produced on an industrial scale, presenting excellent properties and quality. A true physical phenomenon occurring in the RTM process, especially when using vegetable fibers, is related to the absorption of resin by the fiber during the infiltration process. The real effect is related to the slowdown in the advance of the fluid flow front, increasing the mold filling time. This phenomenon is little explored in the literature, especially for non-isothermal conditions. In this sense, this paper does a numerical study of the liquid injection process in a closed and heated mold. The proposed mathematical modeling considers the radial, three-dimensional, and transient flow, variable injection pressure, and fluid viscosity, including the effect of liquid fluid absorption by the reinforcement (fiber). Simulations were carried out using Computational Fluid Dynamic tools. The numerical results of the filling time were compared with experimental results, and a good approximation was obtained. Further, the pressure, temperature, velocity, and volumetric fraction fields, as well as the transient history of the fluid front position and injection fluid volumetric flow rate, are presented and analyzed.

Skin cancer is the most common cancer worldwide, with ultraviolet radiation (UVR) being a major risk factor. Excessive UVR exposure can damage the skin and eyes, making it essential to monitor the Ultraviolet Index (UVI). However, few affordable devices are available for this purpose, limiting public awareness. This study presents the development, calibration, and experimental validation of a low-cost UVI monitoring device against a professional radiometer. The prototype was deployed in Campina Grande, Paraíba, Brazil, and its measurements were systematically compared with data from a nearby automatic meteorological station. The device, based on the UVM-30A sensor, measures UV radiation and transmits UVI values via a mobile application and a public display. Statistical analysis showed strong agreement with reference data, where Pearson Correlation Coefficient r = 0.849 (R² = 0.721 and RMSE = 1.26), and Confidence Index c = 0.917. The device provides an accessible tool for real-time UVI monitoring, promoting public awareness of solar radiation risks and supporting public photoprotection policies.

Resin Transfer Molding (RTM) is a broadly applied composite fabrication technique in which liquid resin is injected into a sealed mold housing a fibrous preform. This technique enables the industrial-scale production of large, complex-shaped components while ensuring high quality and excellent material properties. A notable phenomenon in the Resin Transfer Molding process, particularly when vegetable fibers are used as reinforcement, involves resin absorption by the fibers during the filling process, which causes a deceleration of the fluid flow front, leading to an increase in mold filling time. This phenomenon has been scarcely investigated in the scientific literature, particularly under non-isothermal situations. In this context, this paper focuses on the resin injection in a closed and heated mold, emphasizing the evaluation of the capillary number of the fluid flow. The model incorporates a transient, radial, and 3D flow, variable resin viscosity, and includes the effect of resin absorption by the fibers. Simulations were carried out using CFD techniques, evaluating the effect of fixed injection gauge pressure (2.0 bar) or volumetric flow rate (3.5 × 10⁻⁸ m³/s) on the infiltration transient behavior. The numerical results of the capillary number of the flow, resin viscosity, and resin superficial velocity as a function of radial position were analyzed. Based on the analysis of the capillary number field, with the sole objective of minimizing the potential formation of voids in the manufactured composite, optimal operating parameters were identified, namely, a mold heating temperature of 30 °C and an optimal resin injection condition consisting of a constant volumetric flow rate of 3.5 × 10⁻⁸ m³/s. Further, the volumetric fraction, pressure, and temperature fields are presented and examined. The numerical modeling used builds upon a previously validated numerical framework and extends its application by evaluating the potential generation of voids through the analysis of the capillary number field.