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Indoor and outdoor air pollution are associated with particulate matter concentration of minute size that deeply penetrates the human body and leads to significant problems. These particles led to serious health problems and an increased spread of infection through airborne transmission, especially during the COVID-19 pandemic. Considering the role of particulate matter during the spread of COVID-19, this paper presents a smart wireless sensor node for measuring and monitoring particulate matter concentrations indoors. Data for these concentrations were obtained and used as a risk indicator for airborne COVID-19 transmission. The sensor node was designed to consider air quality monitoring device requirements for indoor applications, such as real-time, continuous, reliable, remote, compact-sized, low-cost, low-power, and accessible. Total energy consumption of the node during measurement and monitoring of particulate matter concentration was minimized using a low-power algorithm and a cloud storage system embedded during software development. Therefore, the sensor node consumed low energy for one cycle of the particulate matter measurement process. This low-power strategy was implemented as a preliminary design for the autonomous sensor node that enables it to integrate with an energy harvester element to harvest energy from ambient (light, heat, airflow) and store energy in the supercapacitor, which extends the sensor node life. Furthermore, the measurement data can be accessed using the Internet of Things and visualized graphically and numerically on a graphical user interface. The test and measurement results showed that the developed sensor node had very small measurement error, which was promising and appropriate for indoor particulate matter concentration measurement and monitoring, while data results were utilized as strategic tools to minimize the risk of airborne COVID-19 transmission. [ABSTRACT FROM AUTHOR]

The indoor environment climate should be controlled by continuously maintaining the temperature and relative humidity to achieve thermal comfort. A monitoring system of both parameters is the first step to improving indoor comfort quality. This paper presents a smart wireless climate sensor node for indoor temperature and humidity monitoring with a powering strategy and design approach for autonomous operation. The data logging results are sent to the cloud using Internet of Things protocol for thermal comfort monitoring and analysis. The monitoring and analysis results are useful to monitor and control the indoor thermal comfort condition for room occupants. A sensor node was designed that includes a low-power mode and compact size features. It consists of a built-in AVR-based microcontroller, a temperature and humidity sensor, and a wireless module with a supercapacitor as the power storage. A low-power algorithm and Internet of Things system were implemented to reduce the total energy consumption as low as possible during operation while improving the thermal comfort quality. This developed sensor node has a small error for temperature, and relative humidity sensed values resulting from calibration. At the same time, it also consumes low power for one cycle of data acquisition. The device was integrated with an Internet of Things monitoring system to monitor indoor thermal comfort in the field experiment. The experiment results showed that the indoor temperature and relative humidity were measured and recorded in the range of 25–30 °C and 30–40%, respectively. This prototype is a preliminary design to achieve an autonomous sensor node with a low-power energy consumption goal. Thus, with this feature, the developed sensor node has potential to couple with a micro energy harvester module toward a fully autonomous active node in further development. [ABSTRACT FROM AUTHOR]

Tire sensors embedded in a vehicle tire are stand-alone autonomous devices. A tire sensor reserve power strategy is crucial due to sensor energy sources limitations for long operational periods. This paper presents an innovative tire sensor powering strategy for the intelligent-tire system. The powering strategy offers a green concept, maintenance-free, and low-cost method in order to extend the tire sensor lifetime for long operating periods. The proposed strategy adopts wireless power transfer (WPT) technology to transfer power to an electrical load mounted on the rotational system without an interconnection cable. It is composed of a power transmitter designed to be mounted on the vehicle's inner fender liner, and a power receiver that provides power to recharge the tire sensor battery/energy storage. The transmitter transfers power from the vehicle battery/accumulator to a power receiver coupled with the tire sensor which is mounted on the vehicle tire inner wall. WPT devices were designed based on induction electromagnetic coupling and can provide an output current up to 1A at 5 V. The proposed powering strategy was verified using a vehicle tire simulator model to emulate rotational motion. A voltage and current sensor module as well microcontroller and data logger modules were utilized as the load for the developed WPT system. The verification experimental and preliminary test results reveal that the proposed strategy can provide constant power to the load (in this case, the voltage is around 4.3 V and the current is around 21.1 mA) although the vehicle tire model was rotated at different speeds from 0 rpm to 800 rpm. The proposed system has the potential and feasibility for implementation in tire sensor power applications in the intelligent-tire system. [ABSTRACT FROM AUTHOR]

The aeroponic plant root environment has a significant role in producing high-quality seed tuber potatoes. However, in lowland and tropical regions, the aeroponic system cannot yield high-quality potato seed because the average environment temperature year-round is high. In a high-temperature environment, the potato plant roots cannot optimally absorb the nutrient solution for healthy plant growth. This paper presents the method used to maintain the aeroponics root chamber temperature conditions. An air conditioning system was adopted to supply air with the optimal temperature range for mini-tuber potato seed cultivation. The vapor compression refrigeration type was applied in the air conditioning system. The root chamber temperature is controlled and monitored using an Arduino Uno board system. The mini-tuber potato seed cultivation field experiment results show the proposed method can maintain the aeroponic root chamber temperature. The root chamber temperature treatment operated in the 10 °C–20 °C range. This temperature range improved the potato seed tuber yield. The potato seed tuber yield potential is observed from the stolon number produced by the mini-tuber potato plants cultivated in the root chamber with the conditioned temperature. The field experiment reveals that the stolon number produced by potato seeds cultivated in the root chamber with conditioned temperature was up to 77% greater than the number of potato seeds cultivated in the root chamber with the unconditioned temperature. [ABSTRACT FROM AUTHOR]