The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Anna Ottenhall - One of the best experts on this subject based on the ideXlab platform.
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Water-stable cellulose fiber foam with antimicrobial properties for bio based Low-Density Materials
Cellulose, 2018Co-Authors: Anna Ottenhall, Tiinamari Seppänen, Monica EkAbstract:New bio-based packaging Materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Water-stable cellulose fiber foams have been produced in a simple one-batch foam-forming process with drying under ambient conditions. The cellulose fiber foams have a Low Density (33–66 kg/m^3) and can inhibit microbial growth; two highly valuable features for insulating packaging Materials, especially in combination with stability in water. Cationic chitosan and/or polyvinylamine have been added during the foam-forming process to give the foams water-stability and antimicrobial properties. The structural and mechanical properties of the cellulose fiber foams have been studied and the antimicrobial properties have been evaluated with respect to both Escherichia coli , a common model bacteria and Aspergillus brasiliensis , a sporulating mold. The cellulose foams containing chitosan had both good water-stability and good antibacterial and antifungal properties, while the foams containing PVAm did disintegrate in water and did not inhibit fungal growth when nutrients were added to the foam, showing that it is possible to produce a bio-based foam material with the desired characters. This can be an interesting Low-Density packaging material for protection from both mechanical and microbial damage without using any toxic compounds.
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Water-stable cellulose fiber foam with antimicrobial properties for bio based Low-Density Materials
Cellulose, 2018Co-Authors: Anna Ottenhall, Tiinamari Seppänen, Monica EkAbstract:New bio-based packaging Materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Water-stable cellulose fiber foams have been produced in a simple one-batch foam-forming process with drying under ambient conditions. The cellulose fiber foams have a Low Density (33–66 kg/m^3) and can inhibit microbial growth; two highly valuable features for insulating packaging Materials, especially in combination with stability in water. Cationic chitosan and/or polyvinylamine have been added during the foam-forming process to give the foams water-stability and antimicrobial properties. The structural and mechanical properties of the cellulose fiber foams have been studied and the antimicrobial properties have been evaluated with respect to both Escherichia coli , a common model bacteria and Aspergillus brasiliensis , a sporulating mold. The cellulose foams containing chitosan had both good water-stability and good antibacterial and antifungal properties, while the foams containing PVAm did disintegrate in water and did not inhibit fungal growth when nutrients were added to the foam, showing that it is possible to produce a bio-based foam material with the desired characters. This can be an interesting Low-Density packaging material for protection from both mechanical and microbial damage without using any toxic compounds.
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Water-stable cellulose fiber foam with antimicrobial properties for bio based Low-Density Materials
Cellulose, 2018Co-Authors: Anna Ottenhall, Tiinamari SeppänenAbstract:New bio-based packaging Materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Water-stable cellulose fiber foams have been produced in a ...
Tiinamari Seppänen - One of the best experts on this subject based on the ideXlab platform.
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Water-stable cellulose fiber foam with antimicrobial properties for bio based Low-Density Materials
Cellulose, 2018Co-Authors: Anna Ottenhall, Tiinamari Seppänen, Monica EkAbstract:New bio-based packaging Materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Water-stable cellulose fiber foams have been produced in a simple one-batch foam-forming process with drying under ambient conditions. The cellulose fiber foams have a Low Density (33–66 kg/m^3) and can inhibit microbial growth; two highly valuable features for insulating packaging Materials, especially in combination with stability in water. Cationic chitosan and/or polyvinylamine have been added during the foam-forming process to give the foams water-stability and antimicrobial properties. The structural and mechanical properties of the cellulose fiber foams have been studied and the antimicrobial properties have been evaluated with respect to both Escherichia coli , a common model bacteria and Aspergillus brasiliensis , a sporulating mold. The cellulose foams containing chitosan had both good water-stability and good antibacterial and antifungal properties, while the foams containing PVAm did disintegrate in water and did not inhibit fungal growth when nutrients were added to the foam, showing that it is possible to produce a bio-based foam material with the desired characters. This can be an interesting Low-Density packaging material for protection from both mechanical and microbial damage without using any toxic compounds.
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Water-stable cellulose fiber foam with antimicrobial properties for bio based Low-Density Materials
Cellulose, 2018Co-Authors: Anna Ottenhall, Tiinamari Seppänen, Monica EkAbstract:New bio-based packaging Materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Water-stable cellulose fiber foams have been produced in a simple one-batch foam-forming process with drying under ambient conditions. The cellulose fiber foams have a Low Density (33–66 kg/m^3) and can inhibit microbial growth; two highly valuable features for insulating packaging Materials, especially in combination with stability in water. Cationic chitosan and/or polyvinylamine have been added during the foam-forming process to give the foams water-stability and antimicrobial properties. The structural and mechanical properties of the cellulose fiber foams have been studied and the antimicrobial properties have been evaluated with respect to both Escherichia coli , a common model bacteria and Aspergillus brasiliensis , a sporulating mold. The cellulose foams containing chitosan had both good water-stability and good antibacterial and antifungal properties, while the foams containing PVAm did disintegrate in water and did not inhibit fungal growth when nutrients were added to the foam, showing that it is possible to produce a bio-based foam material with the desired characters. This can be an interesting Low-Density packaging material for protection from both mechanical and microbial damage without using any toxic compounds.
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Water-stable cellulose fiber foam with antimicrobial properties for bio based Low-Density Materials
Cellulose, 2018Co-Authors: Anna Ottenhall, Tiinamari SeppänenAbstract:New bio-based packaging Materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Water-stable cellulose fiber foams have been produced in a ...
Monica Ek - One of the best experts on this subject based on the ideXlab platform.
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Water-stable cellulose fiber foam with antimicrobial properties for bio based Low-Density Materials
Cellulose, 2018Co-Authors: Anna Ottenhall, Tiinamari Seppänen, Monica EkAbstract:New bio-based packaging Materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Water-stable cellulose fiber foams have been produced in a simple one-batch foam-forming process with drying under ambient conditions. The cellulose fiber foams have a Low Density (33–66 kg/m^3) and can inhibit microbial growth; two highly valuable features for insulating packaging Materials, especially in combination with stability in water. Cationic chitosan and/or polyvinylamine have been added during the foam-forming process to give the foams water-stability and antimicrobial properties. The structural and mechanical properties of the cellulose fiber foams have been studied and the antimicrobial properties have been evaluated with respect to both Escherichia coli , a common model bacteria and Aspergillus brasiliensis , a sporulating mold. The cellulose foams containing chitosan had both good water-stability and good antibacterial and antifungal properties, while the foams containing PVAm did disintegrate in water and did not inhibit fungal growth when nutrients were added to the foam, showing that it is possible to produce a bio-based foam material with the desired characters. This can be an interesting Low-Density packaging material for protection from both mechanical and microbial damage without using any toxic compounds.
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Water-stable cellulose fiber foam with antimicrobial properties for bio based Low-Density Materials
Cellulose, 2018Co-Authors: Anna Ottenhall, Tiinamari Seppänen, Monica EkAbstract:New bio-based packaging Materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Water-stable cellulose fiber foams have been produced in a simple one-batch foam-forming process with drying under ambient conditions. The cellulose fiber foams have a Low Density (33–66 kg/m^3) and can inhibit microbial growth; two highly valuable features for insulating packaging Materials, especially in combination with stability in water. Cationic chitosan and/or polyvinylamine have been added during the foam-forming process to give the foams water-stability and antimicrobial properties. The structural and mechanical properties of the cellulose fiber foams have been studied and the antimicrobial properties have been evaluated with respect to both Escherichia coli , a common model bacteria and Aspergillus brasiliensis , a sporulating mold. The cellulose foams containing chitosan had both good water-stability and good antibacterial and antifungal properties, while the foams containing PVAm did disintegrate in water and did not inhibit fungal growth when nutrients were added to the foam, showing that it is possible to produce a bio-based foam material with the desired characters. This can be an interesting Low-Density packaging material for protection from both mechanical and microbial damage without using any toxic compounds.
Joseph O Deasy - One of the best experts on this subject based on the ideXlab platform.
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su ff t 345 on the suitability of radiographic film for Low Density material dosimetry and photon algorithm verification
Medical Physics, 2006Co-Authors: M Wiesmeyer, J Cui, K Zakaryan, J Alaly, Eric E Klein, S Mutic, D Low, Joseph O DeasyAbstract:Purpose: To assess potential errors in radiographic film dosimetry in Low Density Materials and to compare film measurements to dose estimates of a commercial convolution/superposition photon (CSP) dose calculation algorithm. Method and Materials: A standard film phantom was modified by replacing water‐equivalent slabs (30 HU) in its central portion with very Low‐Density material (−960 HU) to produce a lung slab phantom. Experiments were performed irradiating this phantom with 6 and 18 MV photons and field sizes of 2×2, 5×5, and 10×10 cm with 13 films placed between slabs. With unprocessed film in place, the phantom was then imaged in a computed tomographyscanner and Monte Carlo (MC) and CSP calculations were done for each field size and energy combination. The phantom was then rescanned without film and dose was recalculated using MC to estimate the effect of the film in the prior MC calculations. Results: Measurements and MC calculations demonstrated field size and energy‐dependent dose perturbations at film planes in the Low Density material (up to 20% of maximum dose). In the phantom with film, central axis measurements and MC calculations matched within about 3%. The CSP algorithm was not perturbed by the film and overestimated dose in the Low Density region. Relying on film measurements alone would indicate a maximum overestimate of about 17% for 6 MV beams and 30% for 18 MV beams for the 2×2 cm fields. The filmless MC calculations show the true error to be about 6–9% higher. Conclusion: The error in CSP calculations will be underestimated if film is used as a dosimeter in very Low‐Density Materials. The use of somewhat denser lung‐equivalent Materials (e.g., −700 HU) would likely result in reduced, but still significant, error estimates. Supported by NIH grant RO1 CA85181 and a grant from Sun Nuclear, Corp.
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SU‐FF‐T‐345: On the Suitability of Radiographic Film for Low Density Material Dosimetry and Photon Algorithm Verification
Medical Physics, 2006Co-Authors: M Wiesmeyer, J Cui, K Zakaryan, J Alaly, Eric E Klein, S Mutic, Daniel A. Low, Joseph O DeasyAbstract:Purpose: To assess potential errors in radiographic film dosimetry in Low Density Materials and to compare film measurements to dose estimates of a commercial convolution/superposition photon (CSP) dose calculation algorithm. Method and Materials: A standard film phantom was modified by replacing water‐equivalent slabs (30 HU) in its central portion with very Low‐Density material (−960 HU) to produce a lung slab phantom. Experiments were performed irradiating this phantom with 6 and 18 MV photons and field sizes of 2×2, 5×5, and 10×10 cm with 13 films placed between slabs. With unprocessed film in place, the phantom was then imaged in a computed tomographyscanner and Monte Carlo (MC) and CSP calculations were done for each field size and energy combination. The phantom was then rescanned without film and dose was recalculated using MC to estimate the effect of the film in the prior MC calculations. Results: Measurements and MC calculations demonstrated field size and energy‐dependent dose perturbations at film planes in the Low Density material (up to 20% of maximum dose). In the phantom with film, central axis measurements and MC calculations matched within about 3%. The CSP algorithm was not perturbed by the film and overestimated dose in the Low Density region. Relying on film measurements alone would indicate a maximum overestimate of about 17% for 6 MV beams and 30% for 18 MV beams for the 2×2 cm fields. The filmless MC calculations show the true error to be about 6–9% higher. Conclusion: The error in CSP calculations will be underestimated if film is used as a dosimeter in very Low‐Density Materials. The use of somewhat denser lung‐equivalent Materials (e.g., −700 HU) would likely result in reduced, but still significant, error estimates. Supported by NIH grant RO1 CA85181 and a grant from Sun Nuclear, Corp.
Richard N. Christensen - One of the best experts on this subject based on the ideXlab platform.
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A comparison of open cell and closed cell properties for Low-Density Materials
Journal of Mechanics of Materials and Structures, 2007Co-Authors: Richard N. ChristensenAbstract:The stiffness and strength properties for open cell and closed cell Low-Density Materials are collected and compared. These are the theoretical predictions for the Kelvin cell type and the oct-tet cell type of open cell forms and of the closed cell form from the generalized self-consistent method. The strength properties considered are those for plastic collapse and elastic instability, under both uniaxial stress and dilatational stress conditions.
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Failure criteria for isotropic Materials, applications to Low-Density types
International Journal of Solids and Structures, 2002Co-Authors: Richard N. Christensen, Dennis C. Freeman, Steven J. DeteresaAbstract:Isotropic failure criteria are derived in a general form that applies to both homogeneous Materials and to porous, Low-Density Materials. Specific applications are made to closed-cell foam Materials, with the properties type parameters determined from experimental data. It is found that in addition to the usual yielding type of failure behavior, a fracture type behavior can arise under certain tensile stress conditions and must be taken into explicit account in forming the failure criteria for Low-Density Materials.
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Mechanics of cellular and other Low-Density Materials
International Journal of Solids and Structures, 1999Co-Authors: Richard N. ChristensenAbstract:Both two-dimensional and three-dimensional Low Density Materials are surveyed. The microstructure is usually in a cellular form with some characteristic dimension(s) being small compared to the cell size and with the Density range approaching that at which the loss of material integrity occurs. The mechanical properties of stiffness and strength are considered, along with applications and future opportunities.
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On the relationship of minimal conditions to Low Density material microstructures
Journal of the Mechanics and Physics of Solids, 1996Co-Authors: Richard N. ChristensenAbstract:Abstract A minimal problem is formulated for determining the microstructure of open celled; Low Density Materials. Solutions are found for both crystalline type order and amorphous forms.
