The analytical method for the calculation of the properties of a bolted joint established by the structural Eurocodes proposes the T-stub as a component for the characterization of the tension and compression zones in moment joints. In this article, a review of the state of the art on the T-stub component is developed, where the works developed since it was initially defined, and from the perspectives of formulation, experimentation and numerical simulation are summarized and discussed. Additionally, possible future lines of work are proposed.

Low-cost mechanical ventilators have been developed in order to deal with the shortage of traditional ventilators whose quantity is not sufficient in an emergency context in Perú. Protofy, a company from Spain, designed one of the first low-cost mechanical ventilation systems OxyGEN which was approved by a medicine agency in its country in special context of COVID 19. Therefore, as main of this article, a redesign of this system named OxygenIP.PE was carried out according to local requirements and available technology, but maintaining its working concept based on compression mechanism by cams. Sensors were added and a control algorithm of the respiratory rate was developed. Ventilation curves monitoring over time was implemented; in this sense, a mathematical model of the whole system was developed. OxygenIP.PE was redesigned, fabricated, and tested measuring its ventilation curves over time. Results indicate that this redesign provides a sturdy equipment able to work during a longer lifetime than the original. The replicability of the ventilation curves behavior is ensured, while the mechanism dimensions are adapted for a particular airbag resuscitator. The mathematical model of the whole system can satisfactorily determine the ventilation curves over time and is used to show the air pressure, volume, and flow as a function of the compression arm's angular position and differential pressure through the breathing circuit measurement, furthermore the algorithms designed as a consequence of the mathematical model were implemented for Raspberry and ARDUINO microcontrollers. There were obtained parameters of pressure 10–65 cmH2O, airflow 50–65 l/m, volume 0–0.5 l, at two values of beat per minute (BPM) 15 and 25.

This article presents the design and analysis of an automatic shell broken machine of seeds of Metohuayo (“Caryodendron orinocense Karst”) with a production capacity of 50 kg/h, considering manufacturing and maintenance of local facilities. Metohuayo is the fruit of a tree that grows in various jungle areas of Perú, and the Metohuayo oil is very requested because of its nutritional properties. Starting with these specifications, the design was developed according to the systematic approach established by the VDI-2221 standard, with seven basic steps to analyze the optimum design. Once the definitive project was reached and the commercial components were selected, finite element simulations were performed to analyze the strength of the shell broken system and to evaluate the strength and the dynamic response of the structural support of the machine components. Additionally, complementary experimental studies were performed, such as the analysis of the required force to break the shell or the measurement of their dimensions.

Mechanical ventilation systems require a device for measuring the air flow provided to a patient in order to monitor and ensure the correct quantity of air proportionated to the patient, this device is the air flow sensor. At the beginning of the COVID-19 pandemic, flow sensors were not available in Peru because of the international supply shortage. In this context, a novel air flow sensor based on an orifice plate and an intelligent transducer was developed to form an integrated device. The proposed design was focused on simple manufacturing requirements for mass production in a developing country. CAD and CAE techniques were used in the design stage, and a mathematical model of the device was proposed and calibrated experimentally for the measured data transduction. The device was tested in its real working conditions and was therefore implemented in a breathing circuit connected to a low-cost mechanical ventilation system. Results indicate that the designed air flow sensor/transducer is a low-cost complete medical device for mechanical ventilators that is able to provide all the ventilation parameters by an equivalent electrical signal to directly display the following factors: air flow, pressure and volume over time. The evaluation of the designed sensor transducer was performed according to sundry transducer parameters such as geometrical parameters, material parameters and adaptive coefficients in the main transduction algorithm; in effect, the variety of the described results were achieved by the faster response time and robustness proportionated by transducers of nanostructures based on Anodic Aluminum Oxide (AAO), which enhanced the designed sensor/transducer (ST) during operation in intricate geographic places, such as the Andes mountains of Peru.

This paper presents the results of an experimental study on the behavior of the cold- formed steel shear wall panel (CFSSWP) with fibrocement panels as sheathing, when it is subjected in-plane shear deformations and flexural deformation under perpendicular monotonically increasing horizontal loads on the longest plane. A full-scale housing section was built with three walls and a ceiling using commonly used construction details in El Salvador. The strength and stiffness of the experimental specimen tested overcame significantly critical demand imposed by the technical design standards in this country. Additionally, a simplified finite element model was defined with the objective to analyze stresses in the components. The results of the numerical model were similar to the experimental model tested.