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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Mixdesignsmodell baserat på “Water layer theory” : Validering av betongblandnings modell

Karakurt, Eren, Khawri, Ahmad Shah January 2022 (has links)
This study aims to strengthen the use of "Water layer theory" through a validation of Yahya Ghasemi's mix design model. This is based on an understanding of the components of cement mixes which are the most widely used material globally, as well as its impact on the flowability of the mix. An in-depth understanding of the properties of the mixture ingredients helps to optimize the dosage of the ingredients and can lead to a reduction in the cement and water requirements of the mixture.  The dissertation in this work introduces tests of strength and consistency classes from a new mixture design model based on the relationship between the flow of the mixtures and the specific surface of the particles through a Japanese theory Water layer theory. / Denna studie syftar till att stärka användningen av ”Water layer theory”genom en validering av Yahya Ghasemis mixdesignmodell. Denna är baseradpå en förståelse av komponenterna i cementblandningar som är det mestanvända materialet globalt, samt dess inverkan på blandningens flytbarhet.En djupgående förståelse för blandingrediensernas egenskaper hjälper till attoptimera doseringen av ingredienserna och kan leda till en minskning avblandningens cement- och vattenbehov.  Vår studie introducerar tester av hållfasthet och konsistensklasser ifrån en nyblandningsdesignmodell baserad på förhållandet mellan flödet avblandningarna till partiklarnas specifika yta genom en japansk teori ”Waterlayer theory”. Teorin utgår från att partiklarna är omgivna av en tunn filmsom separerar konerna och smörjer deras yta. Men för att studera filmtjocklekär det nödvändigt att överväga den specifika ytan och packningsdensiteten,vilket denna blandningsmodell gör. I förhållande till detta har vårtexamensarbete undersökt ifall våra tester kan stärka denna modell. Den teoretiska delen av uppsatsen redogör en bakgrund av de begrepp, teorieroch forskning som används för den nya mixdesignsmodellen vi nyttjat.Utöver det teoretiska introduceras metoden samt materialet omtillvägagångssättet, hur bestämmelser för de olika konsistens- ochbetongklasserna hos blandningarna tagits fram.  Den experimentella delen utgör laborationsmätningar av hållfasthet ochkonsistensklasser som tidigare nämns. Här presenteras utföringarna avlaborationer och en redogörelse för de material och redskap som använts fördetta. Material som använts för testerna valdes utifrån tillgängligheten avballast och cement på Högskolan i Halmstad.  Resultatet indikerar goda värden av konsistens- och betongklasser vilketinnebär att mixdesignsmodellens resulterat utifrån Ghasemis forskning äracceptabel. Det bör även noteras att ett bra resultat visas i förhållande till detmaterial och beståndsdelar vi har använt och att vidare studier bör utföras.
2

Aggregates in Concrete Mix Design

Ghasemi, Yahya January 2017 (has links)
The importance of studying the behaviour and properties of concrete can be highlighted by considering the fact that concrete is the most used man-made material in the world. The very first step in making concrete is its mix design and deciding the type and amount of constitutes used in the production of concrete which should fulfil the requirements of the final product. Mix design models are commonly used for the purpose of proportioning concrete ingredients while anticipating the properties of the final product.  The current document deals with the commonly used principals in mix design models namely particle packing theory and excess water/paste layer theories. The conducted studies includes an investigation on accuracy of particle packing models (Toufar, 4C, CPM) and also tries to address the issue with measurement of specific surface area of particles as an essential input to water/paste layer theories.  It has been observed that the particle packing models can predict the packing density with acceptable margin. However, it should be mentioned that the particle packing models by themselves are not mix design models but should be rather used as a part of a mix design. In addition, it was found that the accuracy of calculating the specific surface area of particles based on their size distribution curve can be further improved by assuming angular platonic solids as uniform shape of aggregate instead of traditional approach of assuming spheres for aggregates’ shape.
3

Dinâmica temporal de comunidades planctônicas em lavouras de arroz

Scheer, Graziela Gonçalves January 2015 (has links)
As lavouras de arroz são consideradas áreas úmidas artificiais e produzem uma grande quantidade de alimento ao redor do mundo. Estes agroecossistemas são comparados às áreas úmidas naturais, uma vez que são caracterizadas como ambientes altamente produtivos com potencial para conservação da biodiversidade, principalmente de aves e anfíbios. A coluna d’água presente durante a fase alagada do ciclo do cultivo do arroz contempla uma gama de organismos importantes como cicladores de nutrientes. Neste sentido, o estudo tem por objetivo descrever as mudanças que ocorrem na estrutura e composição da comunidade planctônica na coluna d’água de uma lavoura de arroz durante um ciclo de cultivo, considerando o tempo de irrigação da lavoura. Para tanto, foram coletadas amostras de água uma vez por semana nos quadros de uma lavoura de arroz comercial cultivada com plantio direto e localizada em Charqueadas, RS, durante a safra agrícola 2013/2014, totalizando 11 campanhas amostrais. Foram avaliadas as características químicas e físicas da água de irrigação, a composição do fitoplâncton e zooplâncton e as alterações na cobertura das plantas e da lâmina de água. As medições demonstraram que os teores dos parâmetros selecionados para a caracterização limnológica da lavoura se mostraram amplamente variáveis, com exceção do pH, temperatura e turbidez. Este último, no entanto, juntamente com os parâmetros nitrato, condutividade, nitrogênio amoniacal e matéria orgânica apresentaram altos teores e estiveram associados ao período inicial de irrigação (até 26 dias), provavelmente devido ao distúrbio do solo, aplicação de ureia e processos de decomposição de macrófitas aquáticas. A composição fitoplanctônica demonstrou a predominância de organismos pertencentes às classes Chlorophyceae, Bacillariophyceae, Euglenophyceae, Zygnemaphyceae e Cyanobacteria. No entanto, Zygnemaphyceae foi a classe dominante em termos de biomassa, embora tenha ocorrido um aumento da biomassa das espécies pertencentes à classe Bacillariophyceae uma vez que esta classe contempla mais espécies metafíticas. Gêneros característicos de ambientes eutróficos, tais como Scenedesmus, Trachelomonas e Nitzschia foram dominantes em termos de abundância. A biomassa de cianobactérias foi mais representativa no período final de cultivo provavelmente devido aos altos teores de fósforo e menor disponibilidade de luz. Quanto ao zooplâncton, os rotíferos e as formas juvenis de copépodos foram dominantes durante todo o ciclo do cultivo. Espécies dos gêneros tais como Polyarthra, Keratella, Brachionus e Trichocerca comuns em ambientes eutróficos, foram dominantes em termos de densidade. Embora a condição nutricional da água tenha influenciado a estrutura das comunidades planctônicas, o desenvolvimento da planta de arroz ao longo do ciclo tornou o ambiente mais complexo, o que também pode ter ocasionado alterações na composição destas comunidades. O período pós-perfilhamento representou uma fase de transição nas dinâmicas das populações através da diminuição da incidência de luz e aumento de nichos. A influência positiva do nitrato e da luz sugere que o mecanismo ascendente foi mais importante para a estruturação da comunidade fitoplanctônica. A interação entre as comunidades planctônicas sugerem que o consumo por herbivoria não foi limitado pela produtividade primária. / The rice fields are considered artificial wetlands and produce a lot of food around the world. These agricultural ecosystems are compared with natural wetland, since they are characterized as highly productive environments with the potential for conservation of biodiversity, especially of birds, and amphibians. The water column during the flooded phase of the rice cultivation cycle includes a range of important organisms such as nutrient cyclers. In this sense, the study aims to describe the changes taking place in the structure and composition of the plankton community in the water column of a rice crop during a crop cycle, considering the time of crop irrigation. To this end, water samples were collected once a week in the plots of a commercial rice crop, located in Charqueadas RS, during the 2013/2014 harvest, totaling 11 sampling campaigns. The chemical and physical characteristics of the irrigation water, the composition of the phytoplankton and zooplankton, changes in the canopy of the plants and the water layer depth, were evaluated. Measurements have shown that the concentrations of the selected parameters for the limnological characterization of tillage displayed widely variability, except for pH, temperature and turbidity. The latter, however, together with nitrate, conductivity, ammonia nitrogen and organic matter parameters showed high concentrations and have been associated with the initial irrigation period (until 26 days), probably due to disturbance of the soil, urea application and processes of decomposition of aquatic weeds. The phytoplankton composition demonstrated the predominance of organisms belonging to classes Chlorophyceae, Bacillariophyceae, Euglenophyceae, Zygnemaphyceae and Cyanobacteria. However, Zygnemaphyceae was the dominant class in terms of biomass, although there was an increase in the biomass of species of the class Bacillariophyceae, since this class include more metaphytic species. Genres characteristic of eutrophic environments such as Scenedesmus, Trachelomonas and Nitzschia were dominant in terms of abundance. The biomass of cyanobacteria was more representative in the late cultivation period is likely due to high concentrations of phosphorus and low light availability. Regarding zooplankton, the rotifers and juvenile forms of copepods were dominant throughout the growing cycle. Species of the genera such as Polyarthra, Keratella, Brachionus and Trichocerca, common in eutrophic environments, were dominant in terms of density. Although the nutritional status of water has influenced the structure of plankton communities, the development of the rice plant throughout the cycle became the environment more complex, which may also have caused changes in the composition of these communities. The tillering period represented a transitional phase on the population dynamics by decreasing the incidence of light and increase niches. The positive influence of nitrate and light suggests that the mechanism bottom up was more important to the structure of the phytoplankton community. The interaction between the planktonic communities suggest that consumption by herbivores was not limited by primary productivity.
4

Dinâmica temporal de comunidades planctônicas em lavouras de arroz

Scheer, Graziela Gonçalves January 2015 (has links)
As lavouras de arroz são consideradas áreas úmidas artificiais e produzem uma grande quantidade de alimento ao redor do mundo. Estes agroecossistemas são comparados às áreas úmidas naturais, uma vez que são caracterizadas como ambientes altamente produtivos com potencial para conservação da biodiversidade, principalmente de aves e anfíbios. A coluna d’água presente durante a fase alagada do ciclo do cultivo do arroz contempla uma gama de organismos importantes como cicladores de nutrientes. Neste sentido, o estudo tem por objetivo descrever as mudanças que ocorrem na estrutura e composição da comunidade planctônica na coluna d’água de uma lavoura de arroz durante um ciclo de cultivo, considerando o tempo de irrigação da lavoura. Para tanto, foram coletadas amostras de água uma vez por semana nos quadros de uma lavoura de arroz comercial cultivada com plantio direto e localizada em Charqueadas, RS, durante a safra agrícola 2013/2014, totalizando 11 campanhas amostrais. Foram avaliadas as características químicas e físicas da água de irrigação, a composição do fitoplâncton e zooplâncton e as alterações na cobertura das plantas e da lâmina de água. As medições demonstraram que os teores dos parâmetros selecionados para a caracterização limnológica da lavoura se mostraram amplamente variáveis, com exceção do pH, temperatura e turbidez. Este último, no entanto, juntamente com os parâmetros nitrato, condutividade, nitrogênio amoniacal e matéria orgânica apresentaram altos teores e estiveram associados ao período inicial de irrigação (até 26 dias), provavelmente devido ao distúrbio do solo, aplicação de ureia e processos de decomposição de macrófitas aquáticas. A composição fitoplanctônica demonstrou a predominância de organismos pertencentes às classes Chlorophyceae, Bacillariophyceae, Euglenophyceae, Zygnemaphyceae e Cyanobacteria. No entanto, Zygnemaphyceae foi a classe dominante em termos de biomassa, embora tenha ocorrido um aumento da biomassa das espécies pertencentes à classe Bacillariophyceae uma vez que esta classe contempla mais espécies metafíticas. Gêneros característicos de ambientes eutróficos, tais como Scenedesmus, Trachelomonas e Nitzschia foram dominantes em termos de abundância. A biomassa de cianobactérias foi mais representativa no período final de cultivo provavelmente devido aos altos teores de fósforo e menor disponibilidade de luz. Quanto ao zooplâncton, os rotíferos e as formas juvenis de copépodos foram dominantes durante todo o ciclo do cultivo. Espécies dos gêneros tais como Polyarthra, Keratella, Brachionus e Trichocerca comuns em ambientes eutróficos, foram dominantes em termos de densidade. Embora a condição nutricional da água tenha influenciado a estrutura das comunidades planctônicas, o desenvolvimento da planta de arroz ao longo do ciclo tornou o ambiente mais complexo, o que também pode ter ocasionado alterações na composição destas comunidades. O período pós-perfilhamento representou uma fase de transição nas dinâmicas das populações através da diminuição da incidência de luz e aumento de nichos. A influência positiva do nitrato e da luz sugere que o mecanismo ascendente foi mais importante para a estruturação da comunidade fitoplanctônica. A interação entre as comunidades planctônicas sugerem que o consumo por herbivoria não foi limitado pela produtividade primária. / The rice fields are considered artificial wetlands and produce a lot of food around the world. These agricultural ecosystems are compared with natural wetland, since they are characterized as highly productive environments with the potential for conservation of biodiversity, especially of birds, and amphibians. The water column during the flooded phase of the rice cultivation cycle includes a range of important organisms such as nutrient cyclers. In this sense, the study aims to describe the changes taking place in the structure and composition of the plankton community in the water column of a rice crop during a crop cycle, considering the time of crop irrigation. To this end, water samples were collected once a week in the plots of a commercial rice crop, located in Charqueadas RS, during the 2013/2014 harvest, totaling 11 sampling campaigns. The chemical and physical characteristics of the irrigation water, the composition of the phytoplankton and zooplankton, changes in the canopy of the plants and the water layer depth, were evaluated. Measurements have shown that the concentrations of the selected parameters for the limnological characterization of tillage displayed widely variability, except for pH, temperature and turbidity. The latter, however, together with nitrate, conductivity, ammonia nitrogen and organic matter parameters showed high concentrations and have been associated with the initial irrigation period (until 26 days), probably due to disturbance of the soil, urea application and processes of decomposition of aquatic weeds. The phytoplankton composition demonstrated the predominance of organisms belonging to classes Chlorophyceae, Bacillariophyceae, Euglenophyceae, Zygnemaphyceae and Cyanobacteria. However, Zygnemaphyceae was the dominant class in terms of biomass, although there was an increase in the biomass of species of the class Bacillariophyceae, since this class include more metaphytic species. Genres characteristic of eutrophic environments such as Scenedesmus, Trachelomonas and Nitzschia were dominant in terms of abundance. The biomass of cyanobacteria was more representative in the late cultivation period is likely due to high concentrations of phosphorus and low light availability. Regarding zooplankton, the rotifers and juvenile forms of copepods were dominant throughout the growing cycle. Species of the genera such as Polyarthra, Keratella, Brachionus and Trichocerca, common in eutrophic environments, were dominant in terms of density. Although the nutritional status of water has influenced the structure of plankton communities, the development of the rice plant throughout the cycle became the environment more complex, which may also have caused changes in the composition of these communities. The tillering period represented a transitional phase on the population dynamics by decreasing the incidence of light and increase niches. The positive influence of nitrate and light suggests that the mechanism bottom up was more important to the structure of the phytoplankton community. The interaction between the planktonic communities suggest that consumption by herbivores was not limited by primary productivity.
5

Dinâmica temporal de comunidades planctônicas em lavouras de arroz

Scheer, Graziela Gonçalves January 2015 (has links)
As lavouras de arroz são consideradas áreas úmidas artificiais e produzem uma grande quantidade de alimento ao redor do mundo. Estes agroecossistemas são comparados às áreas úmidas naturais, uma vez que são caracterizadas como ambientes altamente produtivos com potencial para conservação da biodiversidade, principalmente de aves e anfíbios. A coluna d’água presente durante a fase alagada do ciclo do cultivo do arroz contempla uma gama de organismos importantes como cicladores de nutrientes. Neste sentido, o estudo tem por objetivo descrever as mudanças que ocorrem na estrutura e composição da comunidade planctônica na coluna d’água de uma lavoura de arroz durante um ciclo de cultivo, considerando o tempo de irrigação da lavoura. Para tanto, foram coletadas amostras de água uma vez por semana nos quadros de uma lavoura de arroz comercial cultivada com plantio direto e localizada em Charqueadas, RS, durante a safra agrícola 2013/2014, totalizando 11 campanhas amostrais. Foram avaliadas as características químicas e físicas da água de irrigação, a composição do fitoplâncton e zooplâncton e as alterações na cobertura das plantas e da lâmina de água. As medições demonstraram que os teores dos parâmetros selecionados para a caracterização limnológica da lavoura se mostraram amplamente variáveis, com exceção do pH, temperatura e turbidez. Este último, no entanto, juntamente com os parâmetros nitrato, condutividade, nitrogênio amoniacal e matéria orgânica apresentaram altos teores e estiveram associados ao período inicial de irrigação (até 26 dias), provavelmente devido ao distúrbio do solo, aplicação de ureia e processos de decomposição de macrófitas aquáticas. A composição fitoplanctônica demonstrou a predominância de organismos pertencentes às classes Chlorophyceae, Bacillariophyceae, Euglenophyceae, Zygnemaphyceae e Cyanobacteria. No entanto, Zygnemaphyceae foi a classe dominante em termos de biomassa, embora tenha ocorrido um aumento da biomassa das espécies pertencentes à classe Bacillariophyceae uma vez que esta classe contempla mais espécies metafíticas. Gêneros característicos de ambientes eutróficos, tais como Scenedesmus, Trachelomonas e Nitzschia foram dominantes em termos de abundância. A biomassa de cianobactérias foi mais representativa no período final de cultivo provavelmente devido aos altos teores de fósforo e menor disponibilidade de luz. Quanto ao zooplâncton, os rotíferos e as formas juvenis de copépodos foram dominantes durante todo o ciclo do cultivo. Espécies dos gêneros tais como Polyarthra, Keratella, Brachionus e Trichocerca comuns em ambientes eutróficos, foram dominantes em termos de densidade. Embora a condição nutricional da água tenha influenciado a estrutura das comunidades planctônicas, o desenvolvimento da planta de arroz ao longo do ciclo tornou o ambiente mais complexo, o que também pode ter ocasionado alterações na composição destas comunidades. O período pós-perfilhamento representou uma fase de transição nas dinâmicas das populações através da diminuição da incidência de luz e aumento de nichos. A influência positiva do nitrato e da luz sugere que o mecanismo ascendente foi mais importante para a estruturação da comunidade fitoplanctônica. A interação entre as comunidades planctônicas sugerem que o consumo por herbivoria não foi limitado pela produtividade primária. / The rice fields are considered artificial wetlands and produce a lot of food around the world. These agricultural ecosystems are compared with natural wetland, since they are characterized as highly productive environments with the potential for conservation of biodiversity, especially of birds, and amphibians. The water column during the flooded phase of the rice cultivation cycle includes a range of important organisms such as nutrient cyclers. In this sense, the study aims to describe the changes taking place in the structure and composition of the plankton community in the water column of a rice crop during a crop cycle, considering the time of crop irrigation. To this end, water samples were collected once a week in the plots of a commercial rice crop, located in Charqueadas RS, during the 2013/2014 harvest, totaling 11 sampling campaigns. The chemical and physical characteristics of the irrigation water, the composition of the phytoplankton and zooplankton, changes in the canopy of the plants and the water layer depth, were evaluated. Measurements have shown that the concentrations of the selected parameters for the limnological characterization of tillage displayed widely variability, except for pH, temperature and turbidity. The latter, however, together with nitrate, conductivity, ammonia nitrogen and organic matter parameters showed high concentrations and have been associated with the initial irrigation period (until 26 days), probably due to disturbance of the soil, urea application and processes of decomposition of aquatic weeds. The phytoplankton composition demonstrated the predominance of organisms belonging to classes Chlorophyceae, Bacillariophyceae, Euglenophyceae, Zygnemaphyceae and Cyanobacteria. However, Zygnemaphyceae was the dominant class in terms of biomass, although there was an increase in the biomass of species of the class Bacillariophyceae, since this class include more metaphytic species. Genres characteristic of eutrophic environments such as Scenedesmus, Trachelomonas and Nitzschia were dominant in terms of abundance. The biomass of cyanobacteria was more representative in the late cultivation period is likely due to high concentrations of phosphorus and low light availability. Regarding zooplankton, the rotifers and juvenile forms of copepods were dominant throughout the growing cycle. Species of the genera such as Polyarthra, Keratella, Brachionus and Trichocerca, common in eutrophic environments, were dominant in terms of density. Although the nutritional status of water has influenced the structure of plankton communities, the development of the rice plant throughout the cycle became the environment more complex, which may also have caused changes in the composition of these communities. The tillering period represented a transitional phase on the population dynamics by decreasing the incidence of light and increase niches. The positive influence of nitrate and light suggests that the mechanism bottom up was more important to the structure of the phytoplankton community. The interaction between the planktonic communities suggest that consumption by herbivores was not limited by primary productivity.
6

Exploring the Molecular Dynamics of Proteins and Viruses

Larsson, Daniel January 2012 (has links)
Knowledge about structure and dynamics of the important biological macromolecules — proteins, nucleic acids, lipids and sugars — helps to understand their function. Atomic-resolution structures of macromolecules are routinely captured with X-ray crystallography and other techniques. In this thesis, simulations are used to explore the dynamics of the molecules beyond the static structures. Viruses are machines constructed from macromolecules. Crystal structures of them reveal little to no information about their genomes. In simulations of empty capsids, we observed a correlation between the spatial distribution of chloride ions in the solution and the position of RNA in crystals of satellite tobacco necrosis virus (STNV) and satellite tobacco mosaic virus (STMV). In this manner, structural features of the non-symmetric RNA could also be inferred. The capsid of STNV binds calcium ions on the icosahedral symmetry axes. The release of these ions controls the activation of the virus particle upon infection. Our simulations reproduced the swelling of the capsid upon removal of the ions and we quantified the water permeability of the capsid. The structure and dynamics of the expanded capsid suggest that the disassembly is initiated at the 3-fold symmetry axis. Several experimental methods require biomolecular samples to be injected into vacuum, such as mass-spectrometry and diffractive imaging of single particles. It is therefore important to understand how proteins and molecule-complexes respond to being aerosolized. In simulations we mimicked the dehydration process upon going from solution into the gas phase. We find that two important factors for structural stability of proteins are the temperature and the level of residual hydration. The simulations support experimental claims that membrane proteins can be protected by a lipid micelle and that a non-membrane protein could be stabilized in a reverse micelle in the gas phase. A water-layer around virus particles would impede the signal in diffractive experiments, but our calculations estimate that it should be possible to determine the orientation of the particle in individual images, which is a prerequisite for three-dimensional reconstruction. / BMC B41, 25/5, 9:15
7

Contribution à la modélisation microclimatique des situations hivernales en milieu urbain / Contribution of microclimate modeling of urban winter situation

Khalifa, Abderrahmen 09 December 2015 (has links)
En viabilité hivernale, la prévision de l’état de surface des infrastructures s’avère indispensable, et permet une anticipation, une meilleure coordination et une efficacité d’intervention des services d’exploitation. La majorité des pays dispose de modèles de prévision de la température de surface d'infrastructures et des routes en particulier (TSR). La complexité de ces outils d’aide à la décision est croissante, pour servir au mieux les usagers et l’exploitant. Le microclimat urbain influence le bilan énergétique de surface selon différents processus : radiatifs, aérodynamiques et hydrologiques. Néanmoins, d’autres processus physiques anthropiques influencent cette TSR, tel que le trafic. Des travaux ont été menés par le passé concernant l’apport énergétique du trafic dans le bilan thermique de la ville. Celui-ci a fait l’objet d’études sur les périodes estivales et les îlots de chaleur urbains associés. Cependant, dans les cas de dégradations des conditions hivernales de circulation, ces apports énergétiques ont été intégrés de façon marginale dans la modélisation des paramètres de surface de la route. L’absence de cette contribution du trafic dans la modélisation du bilan énergétique de surface explique, dans une certaine limite, la prévision imparfaite de l’état de surface de la route. La bibliographie recense plusieurs études conduites afin d’identifier et de quantifier ces effets du trafic. Elles n'ont pas ou peu traité la perte ou le gain d'énergie causé par le passage des véhicules sur le bilan énergétique de surface, ou sur la modélisation de la TSR. Dans la présente étude, deux approches ont été proposées pour paramétrer le trafic dans le modèle numérique Town Energy Balance (TEB), l'une globale et la seconde détaillée. Leur analyse comparée indique que la seconde a significativement amélioré les résultats de la modélisation de la TSR. Les apports thermiques du trafic ont augmenté la TSR de 2 à 4°C pour la rapprocher des mesures expérimentales (écart de 0.5 à 1°C en moyenne). Elle est le résultat de l’effet cumulatif des différents processus physiques associés au trafic, et varie en fonction de ses paramètres (densité, vitesse de circulation, fluidité, etc.). Une étude de sensibilité a été menée afin d’apprécier les processus physiques responsables de l’amélioration de la TSR. Les résultats indiquent que l’effet turbulent, la densité de flux radiatif ainsi que la densité de flux due aux frottements des pneumatiques contribuent le plus à l'augmentation la TSR. Néanmoins la contribution énergétique de chacun de ces processus dépend à la fois des paramètres du trafic et des conditions météorologiques. Cette étude a présenté également une analyse préliminaire de l’influence de la lame d’eau présente en surface sur la TSR. Cette dernière décroit en fonction de l’épaisseur de la lame d’eau. Les facteurs anthropiques tels que le trafic et l’adjonction de fondants routiers sur la lame d’eau présente en surface sont décrits et discutés, et une paramétrisation proposée en perspectives / In winter maintenance, forecasting the infrastructure surface status is mandatory, to allow anticipation, better coordination and efficiency of services. The majority of countries have forecast models of the infrastructure surface temperature and especially roads one (RST). The complexity of these decision tools is growing, to best serve the users and managers. The urban microclimate influences the surface energy balance according to various processes: radiative, aerodynamic and hydrologic. However, other anthropogenic physical processes influence this RST, such as traffic. Studies have been carried out in the past about the traffic heat input in the town heat balance. These were conducted on the summer periods and associated urban heat islands. However, in case of traffic in adverse winter conditions, these energy contributions were marginally integrated into the modeling of the road surface parameters. The absence of this traffic's contribution in the surface energy balance modeling explains, to a given limit, the imperfect forecasting of road surface status. The literature identifies several studies conducted to identify and to quantify these effects of traffic. They have insufficiently or not treated the loss or gain on energy caused by circulating vehicles on the surface energy balance, or on modeling the RST. In this study, two approaches have been proposed to parameterize the traffic in the Town Energy Balance (TEB) numerical model, this first one being overall and the second one detailed. Their comparative analysis indicates that the second significantly improved the results of the RST modeling. The traffic heat inputs increased RST by 2 to 4°C, results being then closer to experimental measurements (average difference of 0.5 to 1°C). It is the result of the cumulative effect of the various traffic physical processes, and varies according to its parameters (density, vehicle velocity, fluidity, etc.). A sensitivity analysis was conducted to assess the physical processes responsible for the improvement of the RST. The results indicate that the turbulent effect, the radiative heat flux and flux density due to tires friction represent the greatest contribution to RST increase. Nevertheless the energy contribution of each of these processes depends both traffic parameters and weather conditions. This study also presented a preliminary analysis of the influence of a water layer over the surface on the RST. The latter decreases as a function of the thickness of the water layer. Anthropogenic factors such as traffic and the addition of de-icing products into the water layer present on the surface are described and discussed, and a parameterization proposed as a perspective

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