THE SORPTION OF VAPORS BY ACTIVE SILICA

1935 ◽  
Vol 12 (1) ◽  
pp. 41-56 ◽  
Author(s):  
L. M. Pidgeon
Keyword(s):  
Water Vapor ◽  
Silica Gel ◽  
Dynamic Method ◽  
Activated Alumina ◽  
Simple Method ◽  
Commercial Alumina ◽  
Method Of Production ◽  
Effective Sorbent ◽  
Better Than

The sorptive properties of a new active silica have been examined. This sorbent is prepared by the action of acids on the mineral serpentine. The quartz spiral sorption balance has been employed to obtain isotherms for water, benzene and alcohol. Relative rates of sorption have been measured and compared with those for silica gel.Efficiency measurements have also been made, using the dynamic method, with water vapor as the sorbate. Comparative measurements have been carried out on commercial silica gel, and data are cited from the literature for activated alumina. A comparison of the data indicates that active silica is inferior to silica gel but somewhat better than commercial alumina. Its simple method of production combined with reasonably good sorptive properties should result in a cheap and effective sorbent for technical purposes.The type of isotherm exhibited by active silica is similar to that associated with the "chalky" gels described by Holmes. Certain theoretical aspects of sorption by "chalky" and "vitreous" gels are discussed.

scholarly journals New Gridded Product for the Total Columnar Atmospheric Water Vapor over Ocean Surface Constructed from Microwave Radiometer Satellite Data

2021 ◽  
Vol 13 (12) ◽  
pp. 2402
Author(s):  
Weifu Sun ◽  
Jin Wang ◽  
Yuheng Li ◽  
Junmin Meng ◽  
Yujia Zhao ◽  
...  
Keyword(s):  
Water Vapor ◽  
Microwave Radiometer ◽  
Atmospheric Water Vapor ◽  
Global Ocean ◽  
Optimal Interpolation ◽  
Fusion Product ◽  
Mean Deviation ◽  
Atmospheric Water ◽  
Absolute Deviation ◽  
Better Than

Based on the optimal interpolation (OI) algorithm, a daily fusion product of high-resolution global ocean columnar atmospheric water vapor with a resolution of 0.25° was generated in this study from multisource remote sensing observations. The product covers the period from 2003 to 2018, and the data represent a fusion of microwave radiometer observations, including those from the Special Sensor Microwave Imager Sounder (SSMIS), WindSat, Advanced Microwave Scanning Radiometer for Earth Observing System sensor (AMSR-E), Advanced Microwave Scanning Radiometer 2 (AMSR2), and HY-2A microwave radiometer (MR). The accuracy of this water vapor fusion product was validated using radiosonde water vapor observations. The comparative results show that the overall mean deviation (Bias) is smaller than 0.6 mm; the root mean square error (RMSE) and standard deviation (SD) are better than 3 mm, and the mean absolute deviation (MAD) and correlation coefficient (R) are better than 2 mm and 0.98, respectively.

scholarly journals Fish bone-derived interconnected carbon nanofibers for efficient and lightweight microwave absorption

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Yangyang Gu ◽  
Peng Dai ◽  
Wen Zhang ◽  
Zhanwen Su
Keyword(s):  
Microwave Absorption ◽  
Carbon Nanofibers ◽  
Three Dimensional ◽  
Fish Bone ◽  
Absorption Properties ◽  
Simple Method ◽  
Microwave Absorption Properties ◽  
Absorption Performance ◽  
Microwave Absorption Performance ◽  
Better Than

AbstractIn this work, we demonstrated a simple method for preparing three-dimensional interconnected carbon nanofibers (ICNF) derived from fish bone as an efficient and lightweight microwave absorber. The as-obtained ICNF exhibits excellent microwave absorption performance with a maximum reflection loss of –59.2 dB at the filler content of 15 wt%. In addition, the effective absorption bandwidth can reach 4.96 GHz at the thickness of 2 mm. The outstanding microwave absorption properties can be mainly ascribed to its well-defined interconnected nanofibers architecture and the doping of nitrogen atoms, which are also better than most of the reported carbon-based absorbents. This work paves an attractive way for the design and fabrication of highly efficient and lightweight electromagnetic wave absorbers.

Dynamics of water vapor sorption in a CaCl2/Silica Gel/Binder bed: The effect of the bed pore structure

2006 ◽  
Vol 47 (5) ◽  
pp. 776-781 ◽  
Author(s):  
Yu. I. Aristov ◽  
I. V. Koptyug ◽  
L. G. Gordeeva ◽  
L. Yu. Il’ina ◽  
I. S. Glaznev
Keyword(s):  
Water Vapor ◽  
Pore Structure ◽  
Silica Gel ◽  
Water Vapor Sorption ◽  
Vapor Sorption

Evaluation of Luster, Hand Feel and Comfort Properties of Modified Polyester Woven Fabrics

2017 ◽  
Vol 12 (4) ◽  
pp. 155892501701200 ◽  
Author(s):  
Rong Zhou ◽  
Xueli Wang ◽  
Jianyong Yu ◽  
Zhenzhen Wei ◽  
Yu Gao
Keyword(s):  
Water Vapor ◽  
Evaluation System ◽  
Moisture Absorption ◽  
Water Vapor Permeability ◽  
Objective Evaluation ◽  
Cotton Fabrics ◽  
Woven Fabrics ◽  
Vapor Permeability ◽  
Pet Fabric ◽  
Better Than

This paper reports a hollow copolyester fiber modified with polyethylene glycol and sodium-5-sulfo-bis-(hydroxyethyl)-isophthalate, abbreviated as ECDP-H, which has the potential to be a replacement for cotton. The objective evaluation of luster (contrast glossiness) and Kawabata Evaluation System for Fabrics (KES-F) (four Primary Hand Parameters and the Total Hand) of ECDP-H, PET and cotton fabrics are studied in order to investigate the cotton-like appearance of the ECDP-H. The results of moisture regain and dynamic moisture absorption values obtained indicate that the hydrophilicity of the ECDP-H fabric is better than that of PET fabric. The thermo-physiological performance for three fabrics is determined using air and water vapor permeability, wicking, warm-cooling feeling, thermal resistance and vapor resistance. The results show that the ECDP-H fabric has better hand and comfort properties than cotton.

scholarly journals Simple Method for Estimating the Contribution of Neighbouring n-beam Interactions to Two-beam Structure Factors

1988 ◽  
Vol 41 (3) ◽  
pp. 469
Author(s):  
HJ Juretschke ◽  
HK Wagenfeld
Keyword(s):  
Experimental Determination ◽  
Structure Factor ◽  
Beam Structure ◽  
Simple Method ◽  
Experimental Configuration ◽  
Structure Factors ◽  
Special Cases ◽  
Better Than

Unless special precautions are taken, the experimental determination of two-beam structure factors to better than 1 % may include contributions from neighbouring n-beam interactions. In any particular experimental configuration, corrections for such contributions are easily carried out using the modified two-beam structure factor formalism developed recently (Juretschke 1984), once the full indexing of the pertinent n-beam interactions is known. The method is illustrated for both weak and strong primary reflections and its applicability in special cases, as well as for less than perfect crystals, is discussed.

scholarly journals Desiccant Films Made of Low-Density Polyethylene with Dispersed Silica Gel—Water Vapor Absorption, Permeability (H2O, N2, O2, CO2), and Mechanical Properties

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2304 ◽  
Author(s):  
Sängerlaub ◽  
Kucukpinar ◽  
Müller
Keyword(s):  
Water Vapor ◽  
Silica Gel ◽  
Water Vapor Pressure ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Water Vapor Absorption ◽  
Vapor Permeation ◽  
Vapor Absorption ◽  
Effective Water ◽  
Water Vapor Permeation

Silica gel is a well-known desiccant. Through dispersion of silica gel in a polymer, films can be made that absorb and desorb water vapor. The water vapor absorption becomes reversible by exposing such films to a water vapor pressure below that of the water vapor pressure during absorption, or by heating the film. The intention of this study was to achieve a better understanding about the water vapor absorption, permeability (H2O, N2, O2, CO2), and mechanical properties of films with dispersed silica gel. Low-density polyethylene (PE-LD) monolayer films with a nominal silica gel concentration of 0.2, 0.4, and 0.6 g dispersed silica gel per 1 g film (PE-LD) were prepared and they absorbed up to 0.08 g water vapor per 1 g of film. The water vapor absorption as a function of time was described by using effective diffusion coefficients. The steady state (effective) water vapor permeation coefficients of the films with dispersed silica gel were a factor of 2 to 14 (8.4 to 60.2·10−12 mg·cm·(cm²·s·Pa)−1, 23 °C) higher than for pure PE-LD films (4.3·10−12 mg·cm·(cm²·s·Pa)−1, 23 °C). On the other hand, the steady state gas permeabilities for N2, O2, and CO2 were reduced to around one-third of the pure PE-LD films. An important result is that (effective) water vapor permeation coefficients calculated from results of sorption and measured by permeation experiments yielded similar values. It has been found that it is possible to describe the sorption and diffusion behavior of water by knowing the permeability coefficient and the sorption capacity of the film (Peff.≈Seff.·Deff.). The tensile stress changed only slightly (values between 10 and 14 N mm−²), while the tensile strain at break was reduced with higher nominal silica gel concentration from 318 length-% (pure PE-LD film) to 5 length-% (PE-LD with 0.6 g dispersed silica gel per 1 g film).

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