The use of personal protective equipment during the Covid-19 pandemic may inhibit the social interaction and learning process of children. A child respirator that is suitable for children's growth and development has been developed. Its designing process was done by computer-aided design and validated by computational fluid dynamics simulation. The device consists of inhale and exhale system, face cover, and headband. Various air filter is embedded in the inhale system, such as prefilter, HEPA filter, and bamboo-based activated carbon filter. Meanwhile, the exhale system contains HEPA filter only. Preliminary air-flow simulation in various breathing scenarios has been conducted with a result of velocity range from 0.067 up to 1.190 inside the respirator with a 0.47 Pa pressure difference. Flow trajectories analysis shows that the exhaled air is successfully directed to the exhale and inhale system and thus filtration can occur rapidly. These analyses also indicate that the device's average airflow velocity meets the standard requirements for child breathing apparatus. Child respirators using the bamboo-based activated carbon filter can be a great solution in implementing health protocols for children during the Covid-19 pandemic.

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One way to overcome the scarcity of clean water through sustainable approach is by utilizing a solar distillation system. This easy-to-use technology is adopting tubular solar distillation. The three main components, which are the most essential for producing the amount of permeate, are the solar collector, tubular and heat exchanger (HE). This study aims to determine the performance of a tubular solar distillation device equipped with HE using a parabolic trough collector (PTC). The PTC has an area of 5.1 m2 covered with a solar reflective chrome film. Aluminum tubular acts as the feedwater heater. The HE is placed inside the tubular, which acts as a coolant to convert the steam phase into freshwater/permeate and as a feedwater heater to flow into the tubular. In the present study, several parameters were tested: comprise temperature, solar radiation, pressure, humidity, mass flow rate, permeate productivity and efficiency. This study demonstrated the production of a sufficient amount of permeate, which was 5.32 L for 6 h. The efficiency of this device yielded a peak of 48.2% during solar radiation of 813 W/m2 in an average ambient temperature of 32 °C, with an overall average of 44.59%.

Waste material flowing in rivers creates several problems in various aspects, especially in environmental aspects. One of the waste-capturing mechanisms which is widely applied is the trash rack. However, studies show that trash racks have the potential to block river flow which increases the risk of flooding. This study proposes a screw conveyor-based waste capturing mechanism with a modification of the blade’s design resembling a trash rack and integrated with monitoring system using the internet of things. The research was conducted through three methods of virtual prototyping, the CAD (Computer-Aided Design) design method through calculation of machine elements and 3-dimensional design process using Autodesk Inventor Professional 2018 software, the design analysis method which includes computational fluid dynamics analysis and three-dimensional stress analysis using ANSYS software, as well as methods for designing and testing monitoring systems using the open-source NodeMCU board and Google Firebase real-time database. The result obtained from this research are the design and specifications of screw conveyor components, v-belt transmission systems, ball contact bearings, and electric motors with a waste-capturing capacity of 0.368 m3/s. The results of the design validation show that the velocity of water flowing through the design geometry is not significantly reduced and the design is able to withstand a combination of self-load and pressure loads due to water flow. The monitoring website has been able to display real-time sensor-acquired data.

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