The design of a wearable antenna for UHF band at 900 MHz with an integrated front-end for a wireless sensor system targeting remote patient monitoring is presented. A wearable antenna for human body with -7.2 dB gain is demonstrated using five layer torso model. The antenna can deliver 25 μW of power to the rectifier at 4.6 meters distance from the base station emitting P _EIRP =4 W. Local power management circuitry consumes a total power of 4 μW while delivering 10 μW of power for the sensors of the wireless sensor system. The system designed with 0.18pm CMOS process demonstrates the performance of the frontend together with 3D electromagnetic simulation results of the wearable antenna.

The original concept of “Total Prestress” consists of creating compressions in concrete without generating tension stresses for service load, while in "Partially Prestressed” elements, tensions are allowed in the service stage, which would produce some cracking depending on applied loads that will be taken with non-prestressed reinforcement. Using criteria and design recommendations can guarantee maximum flexural capacity and admissible serviceability requirements of partially prestressed elements; however, there is insufficient research for estimating more accurately the required parameters for the design and review of these types of elements. Because of this, the present investigation consisted in the realization of experimental studies in continuous partially prestressed beams with unbonded tendons for the evaluation of the flexural behavior for different stages of load determining the actual stresses and the strains taking into account the structural stiffness decrease and its effect on deflections. The dimensions of the specimens were selected based on common dimensions presented on slabs. The tested specimens considered variables such as the relationship between the length of the continuous spans, the cross-section, and the partial prestressing ratio. Afterward, equations were proposed to predict the decrease in the structural stiffness, depending on the degree of cracking, the type of cross-section, the partial prestressing ratio, and the magnitude of the applied load and the tension and compression stresses to estimate the probable deflections for a particular loading stage. The crack width equation presented a difference of −16% to +18% with respect to the experimental data, while the flexural stiffness equation showed a highly accurate correlation to the experimental data.

The prediction of concrete compressive strength (CSMPa) is fundamental in experimental civil engineering as it enables the optimization of mix design and complements laboratory testing through predictive tools. This study presents a systematic and reproducible methodology for comparing eight regression algorithms—including linear models, neural networks, and boosting methods—applied to three experimental datasets that represent different types of concrete: high-performance concrete (HPC), conventional concrete, and recycled-aggregate concrete (RAC). In order to make such comparison, some performance metrics were calculated (RMSE, MAE, MAPE, $R^2$, and nRMSE) through hyperparameter optimization using RandomizedSearchCV and homogeneous cross-validation. The boosting methods achieved the best performance, with CatBoost standing out by reaching $R^2$ values between 0.92 and 0.95 and RMSE between 3.4 and 4.4 MPa, confirming its inter-dataset stability and generalization capability. These results indicate consistent predictive accuracy across concretes of different compositions and production contexts. As an applied contribution, three interactive inference systems were developed in Google Colab to estimate CS from mix parameters, promoting reproducibility, open access, and practical use in quality-control processes.

Standard maturity methods for concrete monitoring rely primarily on temperature history, often neglecting the influence of internal relative humidity (RH) on hydration kinetics and self-desiccation risks. Continuous in situ monitoring of internal RH remains a challenge due to the high cost, proprietary nature, and lack of reproducibility of existing solutions. This study evaluates a low-cost, open-source embedded sensor array designed to characterize early-age curing behavior through trend-based monitoring—defined here as the evaluation of ensemble consistency and repeatability rather than absolute metrological traceability. The prototype system, based on SHT31 sensors controlled by an ESP32 microcontroller, was embedded in high-performance concrete cylinders (f′c = 45 MPa) to capture the exothermic hydration peak and the equilibration of internal humidity. Results demonstrate that while the sensor encapsulation introduced a geometric disturbance that reduced compressive strength by approximately 25%—a limitation requiring mitigation in structural applications—the system successfully captured reproducible curing transitions. The proposed framework provides an accessible tool for experimental research into internal curing conditions, offering a digital complement to traditional surface-based quality control.

Mineral scale deposits in groundwater-supplied drinking water distribution systems reduce hydraulic efficiency and increase maintenance costs. This study evaluated the effectiveness of citric acid as a descaling agent for natural scale deposits collected from the Benito Juárez and La Joya drinking water distribution systems in Zacatecas, Mexico. The samples were treated with citric acid solutions at concentrations of 1, 2, and 3 M (moles per liter) and characterized before and after treatment using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and inductively coupled plasma optical emission spectrometry (ICP-OES). In addition, statistical analyses were performed using analysis of variance (ANOVA) and Tukey’s test. The scale deposits were composed mainly of calcium carbonate and exhibited differences in their initial mineralogical composition between the two systems. Treatment with citric acid promoted the progressive dissolution of carbonate phases, resulting in mineralogical, chemical, and morphological changes. The 3 M solution produced the highest degree of mineral dissolution, whereas the 1 M and 2 M treatments showed statistically similar behavior. The results demonstrate that scale deposit removal efficiency is influenced by the initial composition of the scale deposits, providing a scientific basis for optimizing remediation strategies in drinking water distribution systems.