scholarly journals Combining visible near‐infrared spectroscopy and water vapor sorption for soil specific surface area estimation

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Maria Knadel ◽  
Lis Wollesen Jonge ◽  
Markus Tuller ◽  
Hafeez Ur Rehman ◽  
Peter Weber Jensen ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Water Vapor ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Water Vapor Sorption ◽  
Vapor Sorption ◽  
Area Estimation

scholarly journals Soil Specific Surface Area Determination by Visible Near-Infrared Spectroscopy

2018 ◽  
Vol 82 (5) ◽  
pp. 1046-1056 ◽  
Author(s):  
Maria Knadel ◽  
Emmanuel Arthur ◽  
Peter Weber ◽  
Per Moldrup ◽  
Mogens Humlekrog Greve ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Surface Area Determination ◽  
Area Determination

Organic Robotics Based on Conducting Polymers

2012 ◽  
Vol 79 ◽  
pp. 87-93
Author(s):  
Hidenori Okuzaki
Keyword(s):  
Water Vapor ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Colloidal Particles ◽  
Water Vapor Pressure ◽  
Isosteric Heat ◽  
Water Vapor Sorption ◽  
Vapor Sorption ◽  
Free Standing

Free-standing films made of poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT/PSS) were prepared by casting water dispersion of its colloidal particles. Specific surface area, water vapor sorption, and electro-active polymer actuating behavior of the resulting films were investigated by means of sorption isotherm, and electromechanical analysis. It was found that the non-porous PEDOT/PSS film, having a specific surface area of 0.13 m2/g, sorbed water vapor of 1080 cm3(STP)/g, corresponding to 87 wt%, at relative water vapor pressure of 0.95. A temperature rise from 25 to 40 °C lowered sorption degree, indicative of an exothermic process, where isosteric heat of sorption decreased with increasing water vapor sorption and the value reached 43.9 kJ/mol, being consistent with the heat of water condensation (44 kJ/mol). Upon application of 10 V, the film underwent contraction of 2.4% in air at 50% relative humidity (RH) which significantly increased to 4.5% at 90% RH. The principle lay in desorption of water vapor sorbed in the film due to Joule heating, where electric field was capable of controlling the equilibrium of water vapor sorption.

scholarly journals Measuring specific surface area of snow by near-infrared photography

2006 ◽  
Vol 52 (179) ◽  
pp. 558-564 ◽  
Author(s):  
Margret Matzl ◽  
Martin Schneebeli
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Near Infrared ◽  
Two Dimensions ◽  
Chemical Models ◽  
Snow Stratigraphy ◽  
Physical And Chemical

AbstractThe specific surface area (SSA) is considered an essential microstructural parameter for the characterization of snow. Photography in the near-infrared (NIR) spectrum is sensitive to the SSA. We calculated the snow reflectance from calibrated NIR images of snow-pit walls and measured the SSA of samples obtained at the same locations. This new method is used to map the snow stratigraphy. The correlation between reflectance and SSA was found to be 90%. Calibrated NIR photography allows quantitative determination of SSA and its spatial variation in a snow profile in two dimensions within an uncertainty of 15%. In an image covering 0.5–1.0 m2, even layers of 1mm thickness can be documented and measured. Spatial maps of SSA are an important tool in initializing and validating physical and chemical models of the snowpack.

scholarly journals Measuring Snow Specific Surface Area with 1.30 and 1.55 μm Bidirectional Reflectance Factors

2018 ◽  
Author(s):  
Adam Schneider ◽  
Mark Flanner ◽  
Roger De Roo
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Near Infrared ◽  
Light Emitting Diodes ◽  
Infrared Light ◽  
Micro Computed Tomography ◽  
Bidirectional Reflectance ◽  
Light Emitting ◽  
New Instrument

Abstract. Snow specific surface area (SSA) is an important physical property that directly affects solar absorption of snow cover. Instrumentation to measure snow SSA is commercially available for purchase, but these instruments are costly and/or remove and destroy snow samples during data collection. To obtain rapid, repeatable, and in situ surface snow SSA measurements, we mounted infrared light emitting diodes and photodiode detectors into a 17 cm diameter black styrene dome. By flashing light emitting diodes and measuring photodiode currents, we obtain accurate 1.30 and 1.55 micron bidirectional reflectance factors (BRFs). We compare measured snow BRFs with X-ray micro computed tomography scans and Monte Carlo photon modeling to relate BRFs to snow SSA. These comparisons show an exponential relationship between snow 1.30 micron BRFs and SSA from which we calculate calibration functions to approximate snow SSA. The techniques developed here enable rapid retrieval of snow SSA by a new instrument called the Near-Infrared Emitting and Reflectance-Monitoring Dome (NERD).

scholarly journals Determination of soil specific surface area by water vapor adsorption: II Dependence of soil specific surface area on clay and organic carbon content

1987 ◽  
Vol 59 (2) ◽  
pp. 67-72
Author(s):  
Raina Niskanen ◽  
Väinö Mäntylahti
Keyword(s):  
Water Vapor ◽  
Organic Carbon ◽  
Specific Surface ◽  
Carbon Content ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mineral Soil ◽  
Water Vapor Adsorption ◽  
Organic Carbon Content ◽  
Vapor Adsorption

The specific surface area of 60 mineral soil samples estimated by water vapor adsorption at 20 % relative humidity ranged from 12.1 ± 3.6 to 225.1 ±18.4 m2/g. Clay (range 1—72 %) and organic carbon content (0.7—14.6 %) together explained 84 % of the variation in the surface area. The regression equation predicting the specific surface area of soil was surface area (m2/g) =2.69+ 1.23clay-% +8.69org.C-%.

scholarly journals Water Vapor Adsorption Capacity of Thermally Fluorinated Carbon Molecular Sieves for CO2Capture

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jin-Young Jung ◽  
Hye-Ryeon Yu ◽  
Se Jin In ◽  
Young Chul Choi ◽  
Young-Seak Lee
Keyword(s):  
Water Vapor ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Molecular Sieves ◽  
Total Pore Volume ◽  
Water Vapor Adsorption ◽  
Carbon Molecular Sieves ◽  
Vapor Adsorption

The surfaces of carbon molecular sieves (CMSs) were thermally fluorinated to adsorb water vapor. The fluorination of the CMSs was performed at various temperatures (100, 200, 300, and 400°C) to investigate the effects of the fluorine gas (F2) content on the surface properties. Fluorine-related functional groups formed were effectively generated on the surface of the CMSs via thermal fluorination process, and the total pore volume and specific surface area of the pores in the CMSs increased during the thermal fluorination process, especially those with diameters ≤ 8 Å. The water vapor adsorption capacity of the thermally fluorinated CMSs increased compared with the as-received CMSs, which is attributable to the increased specific surface area and to the semicovalent bonds of the C–F groups.

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