Proton transport over nanoparticle surface in insulating nanoparticle film-based humidity sensor

We study a proton transport on the surface of insulating nanoparticles for humidity sensors. We use the approach to reveal proton transfer mechanisms in humidity sensitive materials. Hydrophilic and hydrophobic ligand-terminated silica nanoparticle films are adopted for evaluating temperature dependence of the ion conductivity. According to the activation energy of the conductivity, we explain the Grotthuss (H+ transfer) and vehicular (H3O+ transfer) mechanisms are mainly dominant on hydrophilic (-OH terminated) and hydrophobic (acrylate terminated) surface of nanoparticles, respectively. This investigation gives us a clue to understand a proton transfer mechanism in solution-processed humidity-sensitive materials such as oxide nanomaterials.

Influence of Sweat on Joint and Sensor Reliability of E-Textiles

This article addresses reliability under the sweat of interconnection techniques for the mounting surface mounted device (SMD) components and fully printed humidity sensors onto conductive stretchable textile ribbons. Samples underwent testing for the effect of ageing by artificial sweat on their electrical resistance using both alkaline and acidic artificial sweat. The best results in terms of electrical resistance change were obtained for samples soldered to the conductive fibers interwoven in the ribbon. However, this method can damage the ribbon due to the high temperature during soldering and significantly reduce the mechanical properties and flexibility of the ribbon, which can lead to a limited service life of samples. On the other hand, adhesive bonding is a very interesting alternative, where the above-mentioned properties are preserved, but there is a significant effect of sweat ageing on electrical resistance. The results of fully printed graphene-based humidity sensors show that, for the intended use of these sensors (i.e., detection of changes in moisture on the human body), usage of the samples is possible, and the samples are sufficiently reliable in the case of sweat degradation. In addition, the response of the sensor to humidity is quite high: 98% at a relative humidity of 98%.

Roughness sub-layer wind speed model for tropical wooded areas

There are few reports in the literature regarding wind speed near the ground. This work presents a model for wind speed from 4 m above the ground, based on year-round measurements in two meteorological towers. Each tower is equipped with anemometers at five heights, as well as thermometers and pressure and relative humidity sensors. The data is processed using Eureqa artificial intelligence software, which determines the functional relationship between variables using an evolutionary search technique called symbolic regression. Using this technique, models are found for each month under study, in which height and temperature are the variables that most affect wind speed. The model that best predicts the measured wind speeds is then selected. A polynomial function directly proportional to height and temperature is identified as the one that provides the best predictions of wind speed on average, within the rough sub-layer. Finally, future work is identified on testing the model at other locations.

Deep bed drying performance on paddy using hybrid infrared-solar dryer

Hybrid infrared-solar dryer has a potential for drying fruits, vegetables, and grains such as paddy. This study aims to assess the performance of hybrid infrared-solar dryer on paddy in different of deep layer. Three different infrared heaters were used with a power of 25 W, 50 W, and 100 W. The hybrid infrared-solar dryer equipped with sensors placed in an open space so that sunlight can reach the drying chamber. The paddy samples were dried in different of deep layer (2 cm, 4 cm, 6 cm) until it reaches a moisture content of 14%. The input sensors in the drying chamber such as temperature, humidity, and moisture content were recorded using microcontroller and stored in Microsoft Excel® using the Parallax Data Acquisition tool. The algorithm was developed in order to control the heater from the input of temperature and humidity sensors by adjusting turn on/off relay. The study confirmed that the infrared heating power of 100 W is recommended for paddy drying if the ambient temperature is unfavourable (temperature less than 30°C). In general, the hybrid infrared-solar dryer with a power of 25 W-100 W has a potential to dry paddy quickly at a thickness of 2 cm-6 cm with a time range of 90-150 minutes.

loT-based temperature and humidity monitoring system for smart garden

The main objective of this paper is to design an IoT (Internet of Things) to monitor temperature and humidity for smart gardens. Temperature sensors and humidity sensors measure environmental conditions and are processed by a microcontroller. The actuator used is a spray pump that is used to spray water into the air to lower the temperature. Data from the sensors and status from the actuators are sent to the server and can be monitored via a smartphone. The data collected can be analyzed for various purposes. The result obtained is the effect of spraying on temperature reduction.

Indigenous carbon humidity sensor for radiosondes

This paper describes the carbon humidity sensors manufactured in IMD using the material available in the Indian market. These are used in the IMD MK-IV radiosondes for taking routine upper air observation in the network.

Review of Optical Humidity Sensors

Optical humidity sensors have evolved through decades of research and development, constantly adapting to new demands and challenges. The continuous growth is supported by the emergence of a variety of optical fibers and functional materials, in addition to the adaptation of different sensing mechanisms and optical techniques. This review attempts to cover the majority of optical humidity sensors reported to date, highlight trends in design and performance, and discuss the challenges of different applications.