Search results for "gas permeability"

showing 3 items of 3 documents

Effects of soil gas permeability and recirculation flux on soil CO2 flux measurements performed using a closed dynamic accumulation chamber

2009

Abstract Dynamic accumulation chamber methods have been extensively used to estimate the total output of CO2 released from active volcanic area. In order to asses the performance and reliability of a closed dynamic system several tests were carried out with different soil permeabilities and soil CO2 fluxes. A special device was used to create a constant one-dimensional CO2 flux through a soil column with a known permeability. Three permeabilities were investigated, ranging between 3.6 × 10− 2 and 3.5 × 10 μm2, as were several CO2 fluxes (ranging between 1.1 × 10− 6 and 6.3 × 10− 5 kg m− 2 s− 1). The results highlight that the accuracy of soil CO2 flux measurements strictly depends on the so…

HydrologyEmpirical equationsCO2 outputSoil gasCo2 fluxGeologySoil scienceSoil CO2 fluxGas analyzerSoil co2 fluxSoil gas permeabilitySettore GEO/08 - Geochimica E VulcanologiaPermeability (earth sciences)Flux (metallurgy)Measurement deviceGeochemistry and PetrologyClosed dynamic chamberGeology
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Gas Barrier, Rheological and Mechanical Properties of Immiscible Natural Rubber/Acrylonitrile Butadiene Rubber/Organoclay (NR/NBR/Organoclay) Blend N…

2020

In this paper, gas permeability studies were performed on materials based on natural rubber/acrylonitrile butadiene rubber blends and nanoclay incorporated blend systems. The properties of natural rubber (NR)/nitrile rubber (NBR)/nanoclay nanocomposites, with a particular focus on gas permeability, are presented. The measurements of the barrier properties were assessed using two different gases—O2 and CO2—by taking in account the blend composition, the filler loading and the nature of the gas molecules. The obtained data showed that the permeability of gas transport was strongly affected by: (i) the blend composition—it was observed that the increase in acrylonitrile butadiene rubber compon…

Materials science02 engineering and technology010402 general chemistry01 natural scienceslcsh:Technologychemistry.chemical_compound[SPI]Engineering Sciences [physics]Natural rubberOrganoclayGeneral Materials ScienceNitrile rubberlcsh:Microscopylcsh:QC120-168.85Nanocompositelcsh:QH201-278.5lcsh:TCommunicationPermeationpolymer blend021001 nanoscience & nanotechnology0104 chemical sciencesnanoclaychemistryChemical engineeringPermeability (electromagnetism)lcsh:TA1-2040visual_artvisual_art.visual_art_mediumlcsh:Descriptive and experimental mechanicsPolymer blendnanoclay.lcsh:Electrical engineering. Electronics. Nuclear engineeringgas permeabilityAcrylonitrile0210 nano-technologylcsh:Engineering (General). Civil engineering (General)lcsh:TK1-9971
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Cellulose Nanocrystals from Lignocellulosic Raw Materials

2017

Cellulose nanocrystals (CNCs) are unique, renewable top-down nano particles from which coatings with improved gas barrier properties and new functionalities can be prepared. In this paper, the potential for obtaining such high performing nanocrystals from low-cost lignocellulosic by-products or raw materials is proved by a comparison study on CNCs obtained both from cotton linters and kraft pulp, by means of the ammonium persulfate (APS) process. Morphological and chemical characterization of the nanocrystals obtained, as well as the main functional properties of the poly(ethylene terephthalate) coated films, showed quite similar characteristics and performances of CNCs obtained from pure c…

Settore AGR/03 - Arboricoltura Generale E Coltivazioni Arboreelignocellulosic materialgas permeabilitySettore AGR/15 - Scienze E Tecnologie Alimentariammoniumpersulfate (APS) procefilm coatingcellulose nano-crystalfilm coating; gas permeability; cellulose nano-crystals; lignocellulosic materials; ammoniumpersulfate (APS) process;
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