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- Herrmann, T. M., et al.
(författare)
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Effects of mining on reindeer/caribou populations and indigenous livelihoods : Community-based monitoring by Sami reindeer herders in Sweden and First Nations in Canada
- 2014
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Ingår i: The Polar Journal. - : Taylor and Francis Ltd.. - 2154-896X .- 2154-8978. ; 4:1, s. 28-51
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Tidskriftsartikel (refereegranskat)abstract
- This paper explores the effects of human disturbances associated with mine development in the Arctic on habitat and populations of reindeer/caribou (both Rangifer tarandus), and implications for reindeer husbandry and caribou hunting of indigenous Sami people in Sweden and First Nations in Canada. Through three case studies, we illustrate how Cree and Naskapi communities develop community- based geospatial information tools to collect field data on caribou migration and habitat changes, and how Sami reindeer herders use GIS to gather information about reindeer husbandry to better communicate impacts of mining on reindeer grazing areas. Findings indicate impacts on the use of disturbed habitat by reindeer/caribou, on migration routes, and northern livelihoods. The three cases present novel methods for community-based environmental monitoring, with applications in hazards mapping and denote the active engagement of indigenous communities in polar environmental assessments, generating community-oriented data for land use management decisions. They also illustrate how technology can lead to better communication and its role for empowerment.
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| 2. |
- Gonzalez-Borrero, P. P., et al.
(författare)
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Optical band-gap determination of nanostructured WO3 film
- 2010
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 96:6
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Tidskriftsartikel (refereegranskat)abstract
- The optical band-gap energy of a nanostructured tungsten trioxide film is determined using the photoacoustic spectroscopy method under continuous light excitation. The mechanism of the photoacoustic signal generation is discussed. The band-gap energy is also computed by other methods. The absorption coefficient as well as the band-gap energy of three different crystal structures of tungsten trioxide is calculated by a first-principles Green's function approach using the projector augmented wave method. The theoretical study indicates that the cubic crystal structure shows good agreement with the experimental data.
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| 3. |
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| 4. |
- Granqvist, C.-G. 1946-, et al.
(författare)
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Chromogenics for sustainable energy: Some advances in thermochromics and electrochromics
- 2010
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Ingår i: International Journal of Advances in Science and Technology. - 2229-5216. ; 75, s. 55-64
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: Chromogenic materials are able to change their optical properties in response to external stimuli such as temperature (in thermochromic materials) and electrical charge insertion (in electrochromic materials). Below we review some recent advances for these types of materials. Specifically we first discuss the limitations of thermochromic VO2 films for energy efficient fenestration and show from calculations that nanocomposites containing VO2 can have superior properties and display high luminous transmittance and large temperature-dependent solar transmittance modulation. Even better results may be found for nanoparticles of VO2:Mg. In the second part of the paper we survey some recent progress for electrochromic devices and show that W oxide films have increased coloration efficiency when some Ni oxide is added. We also present initial results for flexible electrochromic foils produced by roll-to-roll coating and continuous lamination.Article · Oct 2010 · Advances in Science and Technology
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| 6. |
- Green, Sara V., et al.
(författare)
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Electrochromic properties of nickel oxide based thin films sputter deposited in the presence of water vapor
- 2012
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Ingår i: Thin Solid Films. - : Elsevier BV. - 0040-6090 .- 1879-2731. ; 520:10, s. 3839-3842
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Tidskriftsartikel (refereegranskat)abstract
- Electrochromic nickel oxide based thin films were prepared by reactive RF magnetron sputtering from metallic nickel in the presence of Ar, O-2 and H2O. The water vapor led to enhanced optical modulation and charge capacity. At a wavelength of 550 nm the bleached state transmittance was 0.73 and the transmittance for the colored state was 0.28 and 0.15 for water partial pressures of p(H2O)<10(-3) Pa and p(H2O) similar to 7 x 10(-2) Pa, respectively. The charge densities were 14 and 25 mC/cm(2) for p(H2O)<10(-3) Pa and P-H2O similar to 7 x 10(-2) Pa, respectively. The coloration efficiency was decreased with increased water partial pressure, from about 0.07 to 0.06 cm(2)/mC. Preliminary results show that the H2O promotes an amorphous structure and makes the films increasingly hydrous.
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| 7. |
- Laaksonen, Katri, et al.
(författare)
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Nanoparticles of TiO2 and VO2 in dielectric media : Conditions for low optical scattering, and comparison between effective medium and four-flux theories
- 2014
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Ingår i: Solar Energy Materials and Solar Cells. - : Saunders Elsevier. - 0927-0248 .- 1879-3398. ; 130:SI, s. 132-137
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Tidskriftsartikel (refereegranskat)abstract
- Spectral transmittance and reflectance in the 300 to 2500 nm solar-optical wavelength range were calculated for nanoparticles of titanium dioxide and vanadium dioxide with radii between 5 and 100 nm embedded in transparent dielectric media. Both of the materials are of large importance in green nanotechnologies: thus TiO2 is a photocatalyst that can be applied as a porous film or a nanoparticle composite on indoor or outdoor surfaces for environmental remediation, and VO2 is a thermochromic material with applications to energy-efficient fenestration. The optical properties, including scattering, of the nanoparticle composites were computed from the Maxwell–Garnett effective-medium theory as well as from a four-flux radiative transfer model. Predictions from these theories approach one another in the limit of small particles and in the absence of optical interference. Effects of light scattering can be modeled only by the four-flux theory, though. We found that nanoparticle radii should be less than ~20 nm in order to avoid pronounced light scattering.
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