Absorption of Water Vapor Using Superabsorbent Polymer Composite Material

2020 ◽  
Vol 858 ◽  
pp. 129-139
Author(s):  
Ariel Verzosa Melendres ◽  
Rolan Pepito Vera Cruz
Keyword(s):  
Composite Material ◽  
Water Vapor ◽  
Relative Humidity ◽  
Pure Water ◽  
Polymer Composite Material ◽  
Air Transport ◽  
Water Vapor Absorption ◽  
Vapor Absorption ◽  
Digital Microscope ◽  
Pass Through

The ability of superabsorbent polymers (SAP) to absorb water vapor was studied. A multilayer composite material was prepared where SAP particles were spread in the fluffy fibrous layer located in the middle of the composite structure. Distribution of SAP within the composite material permits air to pass through its porous structure effectively hence allowing efficient contact of air with SAP. SAP was able to decrease the relative humidity of air of a 3-L cabinet from 96% relative humidity (RH) to 52% and 49 % (RH) in 18 hours using 2 g and 4 g of SAP respectively. Study on the water vapor absorption ability of SAP placed together with pure water in a closed cabinet was conducted with and without convective air transport effect. Convective air transport was done by activating the 12 V fan allowing air recirculation speed at rates corresponding to constant voltage settings of 6 V and 12 V. Higher SAP water vapor absorption rate was obtained at higher air recirculation speed. SAP particles swelled after water vapor absorption with slight decrease in the porosity of composite material as observed through the digital microscope.

scholarly journals A Feasibility Study for Simultaneous Estimates of Water Vapor and Precipitation Parameters Using a Three-Frequency Radar

2005 ◽  
Vol 44 (10) ◽  
pp. 1511-1525 ◽  
Author(s):  
R. Meneghini ◽  
L. Liao ◽  
L. Tian
Keyword(s):  
Water Vapor ◽  
Rayleigh Scattering ◽  
Pulse Compression ◽  
Pulse Repetition Frequency ◽  
Center Frequency ◽  
Water Vapor Absorption ◽  
Single Antenna ◽  
Vapor Absorption ◽  
The Cost ◽  
Lower Frequencies

Abstract The radar return powers from a three-frequency radar, with center frequency at 22.235 GHz and upper and lower frequencies chosen with equal water vapor absorption coefficients, can be used to estimate water vapor density and parameters of the precipitation. A linear combination of differential measurements between the center and lower frequencies on one hand and the upper and lower frequencies on the other provide an estimate of differential water vapor absorption. The coupling between the precipitation and water vapor estimates is generally weak but increases with bandwidth and the amount of non-Rayleigh scattering of the hydrometeors. The coupling leads to biases in the estimates of water vapor absorption that depend primarily on the phase state and the median mass diameter of the hydrometeors. For a down-looking radar, path-averaged estimates of water vapor absorption are possible under rain-free as well as raining conditions by using the surface returns at the three frequencies. Simulations of the water vapor attenuation retrieval show that the largest source of error typically arises from the variance in the measured radar return powers. Although the error can be mitigated by a combination of a high pulse repetition frequency, pulse compression, and averaging in range and time, the radar receiver must be stable over the averaging period. For fractional bandwidths of 20% or less, the potential exists for simultaneous measurements at the three frequencies with a single antenna and transceiver, thereby significantly reducing the cost and mass of the system.

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