Acceder

Bibliografías temáticas / Optical properties of snow

Índice

Artículos de revistas
Tesis
Libros
Capítulos de libros
Actas de conferencias
Informes

Literatura académica sobre el tema "Optical properties of snow"

Autor: Grafiati

Publicado: 28 de junio de 2021

Última modificación: 17 de febrero de 2022

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros

Elija tipo de fuente:

Consulte las listas temáticas de artículos, libros, tesis, actas de conferencias y otras fuentes académicas sobre el tema "Optical properties of snow".

Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.

También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.

Artículos de revistas sobre el tema "Optical properties of snow"

1

Pomeroy, J. W. y D. H. Male. "Optical Properties of Blowing Snow". Journal of Glaciology 34, n.º 116 (1988): 3–10. http://dx.doi.org/10.1017/s0022143000008996.

Texto completo

Resumen

Abstract Calculation procedures are developed and results shown for the exact calculation of extinction and meteorological visual range using the blowing-snow mass in the atmosphere and particle radius. Results of the calculations show: (1) For monochromatic radiation, geometrical optics approximations of the extinction efficiency are found to provide results of only moderate accuracy in calculating the extinction of radiation by a single particle. (2) For broad-band radiation, the geometrical optics approximation is sufficiently accurate for many single-particle measurement instruments and applications, except in the infra-red band where Mie theory should be used. (3) For typical blowing-snow particle-size distributions, the shape parameter of the distribution of particle radii and the mean particle radius are very important in broad-band extinction and visual-range modelling. Estimates of blowing-snow quantities from broad-band extinction measurements or visual range from blowing-snow quantities should address the shape and mean value of the snow-particle radius distribution.

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Pomeroy, J. W. y D. H. Male. "Optical Properties of Blowing Snow". Journal of Glaciology 34, n.º 116 (1988): 3–10. http://dx.doi.org/10.3189/s0022143000008996.

Texto completo

Resumen

AbstractCalculation procedures are developed and results shown for the exact calculation of extinction and meteorological visual range using the blowing-snow mass in the atmosphere and particle radius. Results of the calculations show: (1) For monochromatic radiation, geometrical optics approximations of the extinction efficiency are found to provide results of only moderate accuracy in calculating the extinction of radiation by a single particle. (2) For broad-band radiation, the geometrical optics approximation is sufficiently accurate for many single-particle measurement instruments and applications, except in the infra-red band where Mie theory should be used. (3) For typical blowing-snow particle-size distributions, the shape parameter of the distribution of particle radii and the mean particle radius are very important in broad-band extinction and visual-range modelling. Estimates of blowing-snow quantities from broad-band extinction measurements or visual range from blowing-snow quantities should address the shape and mean value of the snow-particle radius distribution.

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Sergent, Claude, Evelyne Pougatch, Marcel Sudul y Barbara Bourdelles. "Experimental investigation of optical snow properties". Annals of Glaciology 17 (1993): 281–87. http://dx.doi.org/10.1017/s0260305500012970.

Texto completo

Resumen

The authors have developed an experimental device in a cold laboratory with the purpose of measuring optical parameters of natural snow depending on grain-size, impurity content and density. Snow samples were prepared from homogeneous layers in order to measure the radiative properties of clearly identified snow types. The first part of this paper describes the working assumptions and the experimental device. In the second part, experiment results are described and discussed. We have compared albedo measurements of different natural snow types with theoretical values derived from physical optics, based on Mie scattering. The albedo evolution of three different snow types submitted to temperature-gradient metamorphism is analyzed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Sergent, Claude, Evelyne Pougatch, Marcel Sudul y Barbara Bourdelles. "Experimental investigation of optical snow properties". Annals of Glaciology 17 (1993): 281–87. http://dx.doi.org/10.3189/s0260305500012970.

Texto completo

Resumen

The authors have developed an experimental device in a cold laboratory with the purpose of measuring optical parameters of natural snow depending on grain-size, impurity content and density. Snow samples were prepared from homogeneous layers in order to measure the radiative properties of clearly identified snow types. The first part of this paper describes the working assumptions and the experimental device. In the second part, experiment results are described and discussed. We have compared albedo measurements of different natural snow types with theoretical values derived from physical optics, based on Mie scattering. The albedo evolution of three different snow types submitted to temperature-gradient metamorphism is analyzed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Warren, Stephen G. "Optical properties of ice and snow". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 377, n.º 2146 (15 de abril de 2019): 20180161. http://dx.doi.org/10.1098/rsta.2018.0161.

Texto completo

Resumen

The interactions of electromagnetic radiation with ice, and with ice-containing media such as snow and clouds, are determined by the refractive index and absorption coefficient (the ‘optical constants’) of pure ice as functions of wavelength. Bulk reflectance, absorptance and transmittance are further influenced by grain size (for snow), bubbles (for glacier ice and lake ice) and brine inclusions (for sea ice). Radiative transfer models for clouds can also be applied to snow; the important differences in their radiative properties are that clouds are optically thinner and contain smaller ice crystals than snow. Absorption of visible and near-ultraviolet radiation by ice is so weak that absorption of sunlight at these wavelengths in natural snow is dominated by trace amounts of light-absorbing impurities such as dust and soot. In the thermal infrared, ice is moderately absorptive, so snow is nearly a blackbody, with emissivity 98–99%. The absorption spectrum of liquid water resembles that of ice from the ultraviolet to the mid-infrared. At longer wavelengths they diverge, so microwave emission can be used to detect snowmelt on ice sheets, and to discriminate between sea ice and open water, by remote sensing. Snow and ice are transparent to radio waves, so radar can be used to infer ice-sheet thickness.This article is part of the theme issue ‘The physics and chemistry of ice: scaffolding across scales, from the viability of life to the formation of planets’.

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Kaasalainen, S., M. Kaasalainen, T. Mielonen, J. Suomalainen, J. I. Peltoniemi y J. Näränen. "Optical properties of snow in backscatter". Journal of Glaciology 52, n.º 179 (2006): 574–84. http://dx.doi.org/10.3189/172756506781828421.

Texto completo

Resumen

AbstractWe present an overview and the first systematic results on the backscatter properties of snow samples with different grain properties. During a 2 year study we investigated the effect of the apparent characteristics of the samples on the intensity enhancement in the direction of exact backscatter (retroreflection), using a specific instrument designed for backscatter measurements. We observed that a sharp peak in intensity (the hot spot) occurs for most types of snow, which is not observable with traditional goniometers. The key factors in the peak properties are the temperature (related to the changes in grain structure) and grain shape and size. These results form the basis of a larger backscatter data archive which is being applied in the systematic study and exploitation of ‘hot spots’ in remote sensing of natural targets, as well as in the development of airborne laser intensity measurement.

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Saito, Masanori, Ping Yang, Norman G. Loeb y Seiji Kato. "A Novel Parameterization of Snow Albedo Based on a Two-Layer Snow Model with a Mixture of Grain Habits". Journal of the Atmospheric Sciences 76, n.º 5 (1 de mayo de 2019): 1419–36. http://dx.doi.org/10.1175/jas-d-18-0308.1.

Texto completo

Resumen

Abstract Snow albedo plays a critical role in the surface energy budget in snow-covered regions and is subject to large uncertainty due to variable physical and optical characteristics of snow. We develop an optically and microphysically consistent snow grain habit mixture (SGHM) model, aiming at an improved representation of bulk snow properties in conjunction with considering the particle size distribution, particle shape, and internally mixed black carbon (BC). Spectral snow albedos computed with two snow layers with the SGHM model implemented in an adding–doubling radiative transfer model agree with observations. Top-snow-layer optical properties essentially determine spectral snow albedo when the top-layer snow water equivalent (SWE) is large. When the top-layer SWE is less than 1 mm, the second-snow-layer optical properties have nonnegligible impacts on the albedo of the snow surface. Snow albedo enhancement with increasing solar zenith angle (SZA) largely depends on snow particle effective radius and also internally mixed BC. Based on the SGHM model and various sensitivity studies, single- and two-layer snow albedos are parameterized for six spectral bands used in NASA Langley Research Center’s modified Fu–Liou broadband radiative transfer model. Parameterized albedo is expressed as a function of snow particle effective radii of the two layers, SWE in the top layer, internally mixed BC mass fraction in both layers, and SZA. Both single-layer and two-layer parameterizations provide band-mean snow albedo consistent with rigorous calculations, achieving correlation coefficients close to 0.99 for all bands.

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Beres, Nicholas D., Deep Sengupta, Vera Samburova, Andrey Y. Khlystov y Hans Moosmüller. "Deposition of brown carbon onto snow: changes in snow optical and radiative properties". Atmospheric Chemistry and Physics 20, n.º 10 (26 de mayo de 2020): 6095–114. http://dx.doi.org/10.5194/acp-20-6095-2020.

Texto completo

Resumen

Abstract. Light-absorbing organic carbon aerosol – colloquially known as brown carbon (BrC) – is emitted from combustion processes and has a brownish or yellowish visual appearance, caused by enhanced light absorption at shorter visible and ultraviolet wavelengths (0.3 µm≲λ≲0.5 µm). Recently, optical properties of atmospheric BrC aerosols have become the topic of intense research, but little is known about how BrC deposition onto snow surfaces affects the spectral snow albedo, which can alter the resulting radiative forcing and in-snow photochemistry. Wildland fires in close proximity to the cryosphere, such as peatland fires that emit large quantities of BrC, are becoming more common at high latitudes, potentially affecting nearby snow and ice surfaces. In this study, we describe the artificial deposition of BrC aerosol with known optical, chemical, and physical properties onto the snow surface, and we monitor its spectral radiative impact and compare it directly to modeled values. First, using small-scale combustion of Alaskan peat, BrC aerosols were artificially deposited onto the snow surface. UV–Vis absorbance and total organic carbon (TOC) concentration of snow samples were measured for samples with and without artificial BrC deposition. These measurements were used to first derive a BrC (mass) specific absorption (m2 g−1) across the UV–Vis spectral range. We then estimate the imaginary part of the refractive index of deposited BrC aerosol using a volume mixing rule. Single-particle optical properties were calculated using Mie theory, and these values were used to show that the measured spectral snow albedo of snow with deposited BrC was in general agreement with modeled spectral snow albedo using calculated BrC optical properties. The instantaneous radiative forcing per unit mass of total organic carbon deposited to the ambient snowpack was found to be 1.23 (+0.14/-0.11) W m−2 per part per million (ppm). We estimate the same deposition onto a pure snowpack without light-absorbing impurities would have resulted in an instantaneous radiative forcing per unit mass of 2.68 (+0.27/-0.22) W m−2 per ppm of BrC deposited.

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Lamare, M. L., J. Lee-Taylor y M. D. King. "The impact of atmospheric mineral aerosol deposition on the albedo of snow and sea ice: are snow and sea ice optical properties more important than mineral aerosol optical properties?" Atmospheric Chemistry and Physics Discussions 15, n.º 16 (27 de agosto de 2015): 23131–72. http://dx.doi.org/10.5194/acpd-15-23131-2015.

Texto completo

Resumen

Abstract. Knowledge of the albedo of polar regions is crucial for understanding a range of climatic processes that have an impact on a global scale. Light absorbing impurities in atmospheric aerosols deposited on snow and sea ice by aeolian transport absorb solar radiation, reducing albedo. Here, the effects of five mineral aerosol deposits reducing the albedo of polar snow and sea ice are considered. Calculations employing a coupled atmospheric and snow/sea ice radiative-transfer model (TUV-snow) show that the effects of mineral aerosol deposits is strongly dependent on the snow or sea ice type rather than the differences between the aerosol optical characteristics. The change in albedo between five different mineral aerosol deposits with refractive indices varying by a factor of 2 reaches a maximum of 0.0788, whereas the difference between cold polar snow and melting sea ice is 0.8893 for the same mineral loading. Surprisingly, the thickness of a surface layer of snow or sea ice loaded with the same mass-ratio of mineral dust has little effect on albedo. On the contrary, multiple layers of mineral aerosols deposited during episodic events evenly distributed play a similar role in the surface albedo of snow as a loading distributed throughout, even when the layers are further apart. The impact of mineral aerosol deposits is much larger on melting sea ice than on other types of snow and sea ice. Therefore, the higher input of shortwave radiation during the summer melt cycle associated with melting sea ice accelerates the melt process.

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

France, J. L., M. D. King, M. M. Frey, J. Erbland, G. Picard, A. MacArthur y J. Savarino. "Snow optical properties at Dome C, Antarctica – implications for snow emissions and snow chemistry of reactive nitrogen". Atmospheric Chemistry and Physics Discussions 11, n.º 4 (18 de abril de 2011): 11959–93. http://dx.doi.org/10.5194/acpd-11-11959-2011.

Texto completo

Resumen

Abstract. Measurements of $e$-folding depth, nadir reflectivity and stratigraphy of the snowpack around Concordia station (Dome C, 75.10° S, 123.31° E) were undertaken and used to determine wavelength dependent coefficients (350 nm to 550 nm) for light scattering and absorption and to calculate potential fluxes of nitrogen dioxide (NO2) from the snowpack due to nitrate photolysis within the snowpack. The stratigraphy of the top 80 cm of Dome C snowpack generally consists of three main layers: a surface of soft windpack (not ubiquitous), a hard windpack and a hoar-like layer beneath the windpack(s). The $e$-folding depths are ~10 cm for the two windpack layers and ~20 cm for the hoar-like layer for solar radiation at a wavelength of 400 nm, about a factor 2–4 larger than previous model estimates for South Pole. Depth integrated photochemical reaction rates of nitrate photolysis in the Dome C snowpack were calculated to give molecular fluxes of NO2 of 5.3×1012 molecules m−2 s−1, 2.3×1012 molecules m−2 s−1 and 8×1011 molecules m−2 s−1 for solar zenith angles of 60°, 70° and 80° respectively for clear sky conditions using the TUV-snow radiative-transfer model. Depending upon the snowpack stratigraphy, a minimum of 85% of the NO2 originates from within the top 20 cm of the Dome C snowpack. It is found that on a multi-annual scale, nitrate photolysis can remove up to 80% of nitrate from surface snow, confirming independent isotopic evidence that photolysis is an important driver of nitrate loss occurring in the EAIS snowpack. However, the model cannot account for the total observed nitrate loss of 90–95% or the shape of the observed nitrate depth profile. A more complete model will need to include also physical processes such as evaporation, re-deposition or diffusion between the quasi-liquid layer on snow grains and firn air to account for the discrepancies.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Más fuentes

Tesis sobre el tema "Optical properties of snow"

1

Gergely, Mathias [Verfasser] y Kurt [Akademischer Betreuer] Roth. "Snow Characterization by Optical Properties / Mathias Gergely ; Akademischer Betreuer: Kurt Roth". Heidelberg : Universitätsbibliothek Heidelberg, 2011. http://d-nb.info/1180067789/34.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Reay, Holly J. "Optical properties of snow and sea-ice : a field and modelling study". Thesis, Royal Holloway, University of London, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.594224.

Texto completo

Resumen

The work contained within this thesis is a field and laboratory study of snowpack and sea-ice optical and physical properties, and a computation modelling study of photochemical reaction rates within snowpack. The contribution of snow photochemistry to snow and atmospheric oxidative capacity is controlled in part by snow albedo and e-folding depths in snow. Albedo and e-folding depths (and thus snow photochemistry) are a function of black carbon mass ratio in snow. The work contained within this thesis demonstrates the complicated response of albedo, e-folding depth (wavelengths 300-600 run) and depth-integrated production rates of N02 and OH radicals to increasing black carbon mass ratio in well-characterised snowpacks of the Barrow OASIS campaign, Alaska. All snowpacks were reworked layered windpacks and were found to have similar responses to changes in black carbon mass ratio. The radiative-transfer calculations demonstrate two light absorption regimes: ice-dominated and black carbon dominated. The ice-dominated and black carbon dominated behaviour of albedo, e-folding depth and depth-integrated production rates with increasing black carbon mass ratios are presented. For black carbon mass ratios greater than 20 ng g-I (wavelength range of 300---600 nm), e-folding depth and depth integrated production rate have an inverse power law relationship with black carbon mass ratio. Doubling the black carbon mass ratio decreases the e-folding depth to -70% of the initial value and for solar zenith angles greater than 60°, doubling the black carbon mass ratio decreases depth-integrated production rates of N02 and OH to - 70% and - 65% of their original values respectively.

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Chukir, Patrik. "Realistické zobrazování sněhu". Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2021. http://www.nusl.cz/ntk/nusl-445479.

Texto completo

Resumen

This diploma thesis follows visualization of snow formations, which are called penitentes. This work includes also collecting the data needed to derive the optical properties of the penitentes material. Which are different phases between snow and ice. For visualization method is used Progressive Transient Photon Beams, that this work implements with the help of SmallUbpb.

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Canestraro, Carla Daniele. "Electrical and optical properties of thin film SnO₂ and SnO₂:F : transparent electrodes in organic photovoltiaics /". Stockholm : Materials Science and Engineering (Materialvetenskap), Kungliga Tekniskan högskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4832.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Carmagnola, Carlo Maria. "Mesure, analyse et modélisation des processus physiques du manteau neigeux sec Implementation and evaluation of prognostic representations of the optical diameter of snow in the SURFEX/ISBA-Crocus detailed snowpack model Snow spectral albedo at Summit, Greenland: measurements and numerical simulations based on physical and chemical properties of the snowpack". Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENU014.

Texto completo

Resumen

La neige est un matériau poreux dont la microstructure change en permanence. L'ensemble de ces transformations, qui prend le nom de ``métamorphisme", est susceptible d'affecter les propriétés thermiques, mécaniques et électromagnétiques de la neige au niveau macroscopique. En particulier, les échanges d'énergie et de matière à l'intérieur du manteau neigeux et entre la neige et l'atmosphère sont fortement influencés par l'évolution au cours du temps de la microstructure de la neige. Une représentation adéquate du métamorphisme dans les modèles de manteau neigeux s'avère donc cruciale. La microstructure d'un matériau poreux peut être raisonnablement décrite en se servant d'un nombre réduit de variables. En effet, la masse volumique, la surface spécifique (SSA) et la distribution de courbure permettent de caractériser la microstructure d'un matériau. Cependant, dans le cas de la neige cette approche n'en est qu'à ses débuts et n'a pas encore été appliquée de façon systématique. Des variables semi-empiriques, difficiles à mesurer et dépourvues de lien direct avec d'autres propriétés physiques, sont encore largement utilisées dans les modèles détaillés de manteau neigeux. Ce travail de thèse s'inscrit dans cette tentative de représenter la microstructure de la neige au cours du temps à l'aide de variables bien définies et mesurables sur le terrain. Parmi ces variables, nous nous sommes attachés notamment à la SSA, qui constitue une grandeur essentielle pour l'étude du manteau neigeux et de son évolution temporelle. Différentes lois d'évolution de la SSA ont été étudiées, à partir de relations empiriques basées sur des ajustements de données expérimentales jusqu'aux modèles physiques qui représentent le flux de la vapeur d'eau entre les grains de neige. Ces lois ont été dans un premier temps testées à l'aide d'un modèle simplifié de manteau neigeux et puis introduites directement dans le modèle SURFEX/ISBA-Crocus. Pour ce faire, la SSA dans Crocus a été transformée en variable prognostique, en remplaçant d'autres variables semi-empiriques préexistantes. Les différentes formulations de l'évolution temporelle de la SSA ont été comparées à des mesures de terrain, acquises lors de deux campagnes à Summit (Groenland) et au Col de Porte (France). Ces mesures ont été effectuées en utilisant de nouvelles techniques optiques et ont permis d'obtenir un riche jeu de données avec une grande résolution verticale. Les résultats montrent que les différentes formulations sont comparables et reproduisent bien les mesures, avec un écart quadratique moyen entre les valeurs de SSA simulées et observées inférieur à 10 m^2/kg. Enfin, nous avons contribué à faire le pont entre la microstructure de la neige et ses propriétés macroscopiques. En particulier, nous nous sommes intéressés au lien entre, d'une part, la SSA et, d'autre part, les propriétés mécaniques et optiques. Dans le premier cas, nous avons investigué la corrélation entre la SSA et la résistance à l'enfoncement mesurée avec un Snow Micro Pen (SMP). Les résultats encore préliminaires semblent indiquer que la SSA peut être dérivée de la masse volumique et de grandeurs micro-mécaniques estimées à partir du signal du SMP avec un modèle statistique. Dans le deuxième cas, nous avons simulé l'albédo de surface à Summit à partir des profils mesurés de masse volumique et de SSA et du contenu en impuretés. Les résultats de cette étude ont démontré que l'albédo spectral peut être correctement simulé à l'aide d'un modèle de transfert radiatif et l'énergie absorbée par le manteau neigeux peut être estimée avec une précision d'environ 1%
Snow is a porous medium whose microstructure is constantly subjected to morphological transformations. These transformations, which take the name of ``metamorphism", are likely to affect the thermal, mechanical and electromagnetic properties of snow at the macroscopic level. Specifically, the exchange of energy and matter within the snowpack and between the snow and the atmosphere above are strongly impacted by the evolution over time of the snow microstructure. Therefore, an adequate representation of metamorphism in snowpack models is crucial. The microstructure of a porous medium can be reasonably described using a reduced number of variables. Indeed, the density, the specific surface area (SSA) and the curvature distribution are able to characterize the microstructure of such a material. However, in the case of snow this approach is still in its infancy and has not yet been systematically applied. Semi-empirical variables, difficult to measure and not directly linked to other relevant physical properties, are still widely used in so-called detailed snowpack models. This work contributes to the attempt to represent the state of the snow using well-defined and easily measurable microstructural variables. Among these variables, we focused particularly on the SSA, which is a key quantity for the study of snow and its temporal evolution. Different evolution laws of SSA were studied, starting from empirical relationships based on experimental data adjustments to physical models that represent the flow of water vapor between snow grains. These laws were initially tested using a simplified snowpack model and then introduced directly into the SURFEX/ISBA-Crocus snowpack model. To this end, the SSA in Crocus was turned into a prognostic variable, replacing other preexisting semi-empirical variables. The different formulations of the temporal evolution of the SSA were compared with field measurements, acquired during two campaigns at Summit (Greenland) and the Col de Porte (France). These measurements were carried out using new optical techniques and yielded a rich dataset with high vertical resolution. The results show that the different formulations are comparable and reproduce well the observations, with an average root-mean-square deviation value between simulated and measured SSA lower than 10 m^/kg. Finally, we contributed to bridge the gap between snow microstructure and macroscopic properties. In particular, we investigated the link between the SSA on the one hand and the mechanical and optical properties on the other hand. In the first case, we investigated the correlation between the SSA and the penetration resistance measured with a Snow Micro Pen (SMP). The preliminary results suggest that the SSA can be retrieved from the snow density and the micro-mechanical parameters estimated from the SMP signal using a statistical model. In the second case, we simulated the surface albedo at Summit from the measured profiles of density, SSA and impurities within the snowpack. The results of this study showed that the spectral albedo can be simulated successfully using a radiative transfer model and the energy absorbed by the snowpack can be estimated with a good accuracy (about 1%)

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Lintzén, Nina. "Mechanical properties of artificial snow". Licentiate thesis, Luleå tekniska universitet, Geoteknologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-16798.

Texto completo

Resumen

Mechanical properties of snow have been a subject of research since the mid-20th century. Theresearch done is based on natural snow. During the last decades the winter business industryhas been growing and also the interest for constructing buildings and artwork of snow. Suchconstructions are generally built using artificial snow, i.e. snow produced by snow guns. Up tothe present constructions of snow are designed based on knowledge by experience. Only minorscientific studies on artificial snow and its properties has been published. Hence it is ofimportance to investigate material properties for artificial snow.A survey of current state of the art knowledge of properties for natural snow was done andbasic material properties for different qualities of artificial snow were investigated. Strengthand deformation properties for artificial snow were evaluated through uniaxial compressivetests where cylindrical test specimens were subjected to different constant deformation rates.The results show that artificial snow at low deformation rates will have a plastic deformationbehavior where the initial deformation will cause a hardening of the snow structure. At higherdeformation rates brittle failure may occur. For artificial snow with a homogeneous and finegrained structure the deformation behavior was found to change from plasticity to brittleness ata certain critical deformation rate. Artificial snow with coarse grained structure was found to bebrittle giving unstructured results independent of the load level.Four point loading was applied on beams of artificial snow to study creep deformation, bendingstrength and to determine the ultimate load for the different snow qualities. The results showedcoarse grained artificial snow underwent relatively small creep deformations. Both the creepbehavior and the ultimate strength varied randomly at the same applied load. Large plasticdeformations were observed with the fine grained artificial without any failure of the beams.The ultimate load was relatively high and repeatable results were achieved for all test.Previous presumptions that coarse grained artificial snow with high density would have highstrength and were not confirmed by the experiments performed on different qualities ofartificial snow. The performed tests indicate that fine grained artificial snow of lower densityhave more predictable strength properties of equally high or higher magnitude as for coarsegrained artificial snow. The plastic deformations were however higher for the fine grainedartificial snow. High deformations are not favorable for structures which should maintain theshape during the winter season. When designing constructions of snow both strength anddeformation properties should be taken into account.
Godkänd; 2013; 20131002 (ninlin); Tillkännagivande licentiatseminarium 2013-10-23 Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Nina Lintzén Ämne: Geoteknik/Soil Mechanics and Foundation Engineering Uppsats: Mechanical Properties of Artificial Snow Examinator: Professor Sven Knutsson, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Tekn. lic. Lars Vikström, LKAB, Luleå Tid: Fredag den 15 november 2013 kl 10.00 Plats: F1031, Luleå tekniska universitet

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Bourgeois, C. Saskia. "The radiative properties of snow at Summit, Greenland /". Zürich : ETH, 2006. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16758.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Wooldridge, Robyn Elaine. "The effects of explosives on the physical properties of snow". Thesis, Montana State University, 2013. http://etd.lib.montana.edu/etd/2013/wooldridge/WooldridgeR0513.pdf.

Texto completo

Resumen

Explosives are a critically important component of avalanche control programs. They are used to both initiate avalanches and to test snowpack instability by ski areas, highway departments and other avalanche programs around the world. Current understanding of the effects of explosives on snow is mainly limited to shock wave behavior demonstrated through stress wave velocities, pressures and attenuation. This study seeks to enhance current knowledge of how explosives physically alter snow by providing data from field-based observations and analyses that quantify the effect of explosives on snow density, snow hardness and snow stability test results. Density, hardness and stability test results were evaluated both before and after the application of 0.9 kg cast pentolite boosters as surface and air blasts. Changes in these properties were evaluated at specified distances up to 5.5 meters (m) from the blast center for surface blasts and up to 4 m from the blast center for air blasts. A density gauge, hand hardness, a ram penetrometer, Compression Tests (CTs), and Extended Column Tests (ECTs) were used. In addition to the field based observations, the measurement error of the density gauge was established in laboratory tests. Results from surface blasts did not provide conclusive data. Air blasts yielded statistically significant density increases out to a distance of 1.5 m from the blast center and down to a depth of 50 centimeters (cm). Statistically significant density increases were also observed at the surface (down to 20 cm) out to a distance of 4 m. Hardness data showed little to no measurable change. Results from CTs showed a statistically significant decrease in the number of taps needed for column failure 4 m from the blast center in the post-explosive tests. A smaller data set of ECT results showed no overall change in ECT score. The findings of this study provide a better understanding of the physical changes in snow following explosives, which may lead to more effective and efficient avalanche risk mitigation.

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Lampkin, Derrick Julius. "Optical Remote Sensing for Monitoring Evolution of Ablation Season Mountain Snow Cover". Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1120%5F1%5Fm.pdf&type=application/pdf.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Cuthill, Fergus. "The influence of snow microstructure and properties on the grip of winter tyres". Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/29534.

Texto completo

Resumen

The friction of tyres on roads has been of practical importance for many years with nearly 80% of terrestrial traffic making use of rubber tyres. Tyres provide the grip required for vehicle acceleration, braking and cornering. In order for a tyre to grip on a snow covered surface friction mechanisms such as “ploughing”, (where sharp tread block edges dig into and break bonds between the snow grains) and fluid film lubrication must be considered. These are not present when a tyre interacts with tarmac. In addition metamorphism of the snow over time can result in variations of the structure and mechanical properties, this can occur rapidly especially when dealing with temperatures close to snows melting point. When full car-scale outdoor testing is carried out the snow conditions cannot be controlled and vary daily. This means the snow properties must be measured every day so that any observed variations in friction can be attributed to the tyres rather than the snow. At present the simple measurements being carried out on the snow tracks have not proved sufficient to pick up on the variations in the snow. This leads to inconsistent results: one tyre behaves differently on two different days, even though the snow was measured to be the same. This has resulted in the need for further study of the way snow variations influence the grip of winter tyres. The primary aim of this study is to identify which snow properties contribute to the friction of tyres on snow and be able to estimate the friction from measurements of snow properties. This work is the first comprehensive study to combine: multiple snow properties, microstructure characterisation, measurement of friction behaviour and different snow (both artificial and natural). In order to study the way snow affects the grip of winter tyres, methods of manufacturing artificial snow with consistent mechanical properties and microstructure are used. A method of blending ice chips (a solid state fracturing process) and compressing the resulting snow to form a test track was developed during a previous PhD carried out in our group. An alternate snow microstructure was created by using an established process of creating snow by vapour deposition. The process was simplified and downscaled, the resulting snow consisted of large dendritic grains, very different to the blended ice chips. Both snows were pressed in identical manners to create snow testing tracks. In addition, natural snow collected from the field was tested to compare with the artificial snow. In order to investigate how the variations in the snow affected the friction of tyres extensive testing was carried out in a cold room using a linear tribometer, using procedures established in previous studies. Two analytical rubber samples were used to investigate the friction, a rounded edge sample and a siped sample. Testing was carried out at -10°C at speeds of 0.01m/s, 0.1m/s and 1m/s. A significant part of this PhD involved the development of new methods and equipment which have not been used to study snow in this way before. In order to characterise mechanical properties, shear testing, compression testing and cohesion testing were carried out. To investigate snow microstructure, surface profilometry, microscopy and X-ray microtomography were used. Correlating the changes observed in snow characteristics with the changes recorded in the coefficient of friction has allowed the development of an empirical equation. This can be used to predict the coefficient of friction of a given snow based on three relatively simple snow measurements: a compression test to calculate the effective modulus, a roughness measurement to calculate the peak count density and a snow penetration test. For the first time this study allows us to use the empirical equation to estimate the relative contributions of the ploughing and surface friction mechanisms to the total friction. This allows the comparison of full car-scale test data as it is now possible to account for variations in the snow test tracks.

Los estilos APA, Harvard, Vancouver, ISO, etc.

Más fuentes

Libros sobre el tema "Optical properties of snow"

1

Norn, Mogens S. Eskimo snow goggles in Danish and Greenlandic Museums, their protective and optical properties. Copenhagen: Kommissionen for Videnskabelige Undersøgelser i Grønland, 1996.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Warren, Stephen G. Optical properties of CO ́ice and CO ́snow in the ultraviolet, visible, and infrared: Final report on NASA grant NAGW-1734. [Washington, DC: National Aeronautics and Space Administration, 1993.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

1975-, Qiu Min, ed. Optical properties of nanostructures. Singapore: Pan Stanford, 2011.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Jan, Vlieger, ed. Optical properties of surfaces. London: Imperial College Press, 2002.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Martinez, G., ed. Optical Properties of Semiconductors. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-015-8075-5.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Zaitsev, Alexander M. Optical Properties of Diamond. Berlin, Heidelberg: Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/978-3-662-04548-0.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Klingshirn, C., ed. Optical Properties. Part 2. Berlin/Heidelberg: Springer-Verlag, 2004. http://dx.doi.org/10.1007/b98078.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Kasper, E. y C. Klingshirn, eds. Optical Properties. Part 3. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-47055-7.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Klingshirn, C., ed. Optical Properties. Part 1. Berlin/Heidelberg: Springer-Verlag, 2001. http://dx.doi.org/10.1007/b55683.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Optical properties of solids. 2^a ed. Oxford: Oxford University Press, 2010.

Buscar texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Más fuentes

Capítulos de libros sobre el tema "Optical properties of snow"

1

Cook, Joseph, Mark Flanner, Christopher Williamson y S. McKenzie Skiles. "Bio-optical Properties of Terrestrial Snow and Ice". En Springer Series in Light Scattering, 129–63. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-20587-4_3.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Hall, Dorothy K. y Jaroslav Martinec. "An introduction to the optical, thermal and electrical properties of ice and snow". En Remote Sensing of Ice and Snow, 1–9. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-4842-6_1.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Perovich, D. K. "Ultraviolet Radiation and the Optical Properties of Sea Ice and Snow". En Ecological Studies, 73–89. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-642-56075-0_4.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Singh, Ravi Chand, Gurpreet Singh y Anita Hastir. "Structural and Optical Properties of Dysprosium-Doped SnO2 Nanocrystals and Their LPG-Sensing Behavior". En Processing and Properties of Advanced Ceramics and Composites VII, 349–60. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2015. http://dx.doi.org/10.1002/9781119183860.ch33.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Singh, Gurwinder Pal, Navneet Kaur, Abhinav, Sacheen Kumar y Dinesh Kumar. "Effect of Dopant Concentration on Structural and Optical Properties of Cu Doped SnO2". En Springer Proceedings in Physics, 111–17. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-29096-6_14.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Langer, Michael S. y Richard Mann. "Tracking through Optical Snow". En Biologically Motivated Computer Vision, 181–88. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/3-540-36181-2_18.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Fang, L. M. y Xiao Tao Zu. "Microstructure and Optical Properties of Fe-Doped SnO₂ Nanoparticles Synthesized by Hydrothermal Method". En Advanced Materials Research, 683–86. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-463-4.683.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Boumezoued, A., K. Guergouri, C. Azizi, A. Aberkane y A. Khial. "Investigation of Structural, Optical and Electrical Properties of Al Doped SnO2 Thin Films Synthesized by Sol-Gel". En Proceedings of the Third International Symposium on Materials and Sustainable Development, 3–9. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-89707-3_1.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Domine, Florent. "Physical Properties of Snow". En Encyclopedia of Earth Sciences Series, 859–63. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-90-481-2642-2_422.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Benkara, S., H. Ghamri y M. Zaabat. "Study of Structural, Morphological and Optical, Properties of Fe Doped SnO2 Semiconductor Thin Films Prepared by Sol-Gel Technique". En Proceedings of the Third International Symposium on Materials and Sustainable Development, 676–82. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-89707-3_71.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Actas de conferencias sobre el tema "Optical properties of snow"

1

Perovich, Donald K., Gary A. Maykut y Thomas C. Grenfell. "Optical Properties Of Ice And Snow In The Polar Oceans. I: Observations". En 1986 Technical Symposium Southeast, editado por Marvin A. Blizard. SPIE, 1986. http://dx.doi.org/10.1117/12.964238.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Grenfell, Thomas C. y Donald K. Perovich. "Optical Properties Of Ice And Snow In The Polar Oceans. II: Theoretical Calculations". En 1986 Technical Symposium Southeast, editado por Marvin A. Blizard. SPIE, 1986. http://dx.doi.org/10.1117/12.964239.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Koshy, Jiji, Anoop Chandran, Soosen Samuel y K. C. George. "Optical properties of SnO2 nanoparticles". En LIGHT AND ITS INTERACTIONS WITH MATTER. AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4898239.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Sohila, S., M. Rajalakshmi, C. Muthamizhchelvan y S. Kalavathi. "Optical properties of Fe-doped SnO2 nanoparticles". En SOLID STATE PHYSICS: Proceedings of the 56th DAE Solid State Physics Symposium 2011. AIP, 2012. http://dx.doi.org/10.1063/1.4709974.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Liao, Bo-Huei, Cheng-Chung Lee, Chien-Cheng Kuo y Ping-Zen Chen. "Enhancing the Optical and Electrical Properties of SnO2 Films by Plasma Etching Deposition". En Optical Interference Coatings. Washington, D.C.: OSA, 2010. http://dx.doi.org/10.1364/oic.2010.mc5.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Ching-Prado, Eleicer, Hector Miranda y Amanda Watson. "Optical Properties of SnO2 and SnO2:F - An Experimental and Theoretical Approach". En 2019 7th International Engineering, Sciences and Technology Conference (IESTEC). IEEE, 2019. http://dx.doi.org/10.1109/iestec46403.2019.00026.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Ahmad, Naseem, Shakeel Khan, Richa Bhargava y Mohd Mohsin Nizam Ansari. "Study of lattice strain and optical properties of nanocrystalline SnO2". En 2ND INTERNATIONAL CONFERENCE ON CONDENSED MATTER AND APPLIED PHYSICS (ICC 2017). Author(s), 2018. http://dx.doi.org/10.1063/1.5032398.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Xing, Dan-Xu, Pei-Ji Wang y Chang-Wen Zhang. "The Electronic Structures and Optical Properties in Nitrogen-Doped SnO2". En 4th 2016 International Conference on Material Science and Engineering (ICMSE 2016). Paris, France: Atlantis Press, 2016. http://dx.doi.org/10.2991/icmse-16.2016.92.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Stjerna, B. A. y Claes-Goeran Granqvist. "Optical and electrical properties of doped rf-sputtered SnOx films". En Optical Materials Technology for Energy Efficiency and Solar Energy, editado por Anne Hugot-Le Goff, Claes-Goeran Granqvist y Carl M. Lampert. SPIE, 1992. http://dx.doi.org/10.1117/12.130505.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Saipriya, S. y R. Singh. "Optical properties of (SnO[sub 2]∕Cu-Zn ferrite) multilayers". En SOLID STATE PHYSICS: PROCEEDINGS OF THE 57TH DAE SOLID STATE PHYSICS SYMPOSIUM 2012. AIP, 2013. http://dx.doi.org/10.1063/1.4791194.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Informes sobre el tema "Optical properties of snow"

1

Roesler, Collin S. Particulate Optical Closure: Reconciling Optical Properties of Individual Particles with Bulk Optical Properties. Fort Belvoir, VA: Defense Technical Information Center, enero de 1995. http://dx.doi.org/10.21236/ada300437.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Self, S. A. Optical properties of flyash. Office of Scientific and Technical Information (OSTI), enero de 1990. http://dx.doi.org/10.2172/7027281.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Self, S. A. Optical properties of flyash. Office of Scientific and Technical Information (OSTI), julio de 1989. http://dx.doi.org/10.2172/7069542.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Self, S. A. Optical properties of flyash. Office of Scientific and Technical Information (OSTI), enero de 1992. http://dx.doi.org/10.2172/5601114.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Klepfer, Robert O., Madarasz III y Frank L. Excitonic Nonlinear Optical Properties. Fort Belvoir, VA: Defense Technical Information Center, junio de 1996. http://dx.doi.org/10.21236/ada311109.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Self, S. A. Optical properties of flyash. Office of Scientific and Technical Information (OSTI), octubre de 1990. http://dx.doi.org/10.2172/6164447.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Self, S. A. Optical properties of flyash. Office of Scientific and Technical Information (OSTI), abril de 1992. http://dx.doi.org/10.2172/5127564.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Self, S. A. Optical properties of flyash. Office of Scientific and Technical Information (OSTI), noviembre de 1991. http://dx.doi.org/10.2172/5991403.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Self, S. A. Optical properties of flyash. Office of Scientific and Technical Information (OSTI), abril de 1990. http://dx.doi.org/10.2172/7245066.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Vaughn, James, William M. Balch y James Novotny. Optical Properties of Viruses. Fort Belvoir, VA: Defense Technical Information Center, septiembre de 1997. http://dx.doi.org/10.21236/ada628528.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Ofrecemos descuentos en todos los planes premium para autores cuyas obras están incluidas en selecciones literarias temáticas. ¡Contáctenos para obtener un código promocional único!