Outdoor Active Water-Harvesting and Dehumidification System
01 Oct 2019-
Abstract: An electrical outdoor system designed to harvest water from the atmospheric humidity and assist in improving visibility in foggy weather is presented in this paper. The system named (Oceanus) is a tri-mode prototype that demonstrates the use of the Thermoelectric coolers and sensors in atmospheric water vapor harvesting, fog dissipation, and humidity adjustment through condensation; in contrast to the traditional hard-to-deploy and limited non-electrical passive techniques like fog catchers and humidity traps that are used in elevated terrain to obtain water. The compact, environment-friendly, cost and power efficient system extracts water directly from the atmosphere for storage or direct use, and the portability of the design allows for different flexible applications depending on the need of the user and the number of units. In countries with a high humidity index where temperatures and infection rates are high, Oceanus may contribute to the reduction of humidity levels and create a healthier and comfortable environment if it covers a relatively sufficient area.
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Topics: Humidity (54%)
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Abstract: Fog precipitation has long been assumed as an additional water source in the relic laurel ecosystems of the Canary Islands, located at 500–1400 m MSL. However, to what extent fog water can contribute to the laurel forest water balance is not yet clear. Combining data from artificial fog catchers and a physically based impaction model, the authors evaluated the potential contribution of fog water captured by needle-leafed Erica arborea L. trees in a selected watershed of the Garajonay National Park (La Gomera Island) for a 2-yr period (February 2003–January 2005). Fog water collection was measured with artificial catchers at four micrometeorological stations placed at 1145, 1185, 1230, and 1270 m MSL. Average fog water collection was only significant at the highest measurement site (one order of magnitude greater than at lower altitudes), totaling 496 L m−2 yr−1 during the 2-yr period. The average fog water yield in the first and second annual periods ranged between 0.2–5.0 and 0.1–2.1 L m−2 day−1...
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68 Citations
Open access•
01 Jan 2010-
Abstract: In this article we propose a simple and low-cost experimental set-up through which science educators can demonstrate the Seebeck effect using a thermocouple and an instrumentation amplifier. The experiment can be set up and conducted during a 1-hour laboratory session. When a temperature gradient is introduced along the length of a metal wire, electrons start to diffuse from one end to the other end of the wire (Chambers, 1977). The direction of electron diffusion depends on the electrical properties of the metal wire. By convention, if electrons diffuse from the hot end towards the cool end of the wire, a negative thermoelectric emf is generated in the wire with respect to the hot end. Similarly, if electrons diffuse from the cool end towards the hot end of the wire, a positive thermoelectric emf is generated in the wire with respect to the hot end. This phenomenon in metals, known as the Seebeck effect, was first observed by physicist Thomas Johann Seebeck (1770-1831). Seebeck observed that when two dissimilar metal wires are formed into a closed loop and its two junctions are held at different temperatures, it has the ability to deflect a galvanometer needle. The phenomenon was later attributed to electrical current through the wires.
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Topics: Thermoelectric effect (57%), Thermocouple (54%)
10 Citations