The increasing frequency of sporadic weather patterns in the last decade, especially major winter storms, demands improvements in current weather forecasting techniques. Recently, there are growing interests in stratospheric forecasting because of its potential enhancements of weather forecasts. The dominating factors of northern hemisphere wintertime variation of the general circulation in the stratosphere is a phenomenon called stratospheric sudden warming (SSW) events. It is shown in multiple studies that SSW and cosmic ray muon flux variations are strongly correlated with the effective atmospheric temperature changes, which suggests that cosmic ray detectors could be potentially used as meteorological applications, especially for monitoring SSW events. A method for determining the effective temperature with cosmic ray flux measurements is studied in this work by using statistical modeling techniques, such as k-fold cross validation and partial least square regression. This method requires the measurement of the vertical profile of the atmospheric temperature, typically measured by radiosonde, for training the model. In this study, cosmic ray flux measured in Atlanta and Yakutsk are chosen for demonstrating this novel technique. The results of this study show the possibility of realtime monitoring on effective temperature by simultaneous measurement of cosmic ray muon and neutron flux. This technique can also be used for studying the historical SSW events using the past world wide cosmic ray data.

No verão do Rio Grande do Sul (RS) são frequentes os registros de temperatura do ar acima de 30°C por alguns dias consecutivos, o que gera um fenômeno denominado de ondas de calor que associadas à atuação da massa de ar tropical continental, afetam o conforto térmico e o bem-estar das pessoas. Essa constante troca de massas de ar ocasiona extremos de temperatura e interfere no conforto térmico. Os estudos sobre o conforto térmico usando dados horários no RS são raros, e, portanto, são desconhecidas as diferentes condições térmicas para a sensação do conforto. O presente estudo analisou a sensação de conforto térmico e sua variabilidade para nove municípios do RS empregando o Índice de Temperatura Efetiva (ITE) para os verões de 2006/2007 a 2013/2014. Essa sensação varia no RS de acordo com a região geográfica, onde se identificou três padrões de conforto térmico na análise do ITE máximo e mínimo. Os municípios de menor altitude, como Porto Alegre, Santa Maria e Uruguaiana, são os que mais registraram desconforto térmico. A faixa térmica do calor moderado ocorre com maior frequência no ITE das máximas, seguido pela faixa de calor. A sensação de calor extremo é registrada nesses três municípios. No ITE das mínimas a faixa do confortável é predominante, seguida pela de ligeiramente quente. A maior continentalidade de Santa Maria e Uruguaiana faz com que esses dois municípios sejam os mais quentes do RS. Bento Gonçalves, Caçapava do Sul e Erechim, com altitudes de 623 m, 421 m e 777 m, respectivamente, registram sensação térmica de calor moderado nas máximas de ITE, seguido pela sensação de ligeiramente quente. Já as mínimas correspondem à faixa do confortável e de ligeiramente fresco. Torres e Rio Grande, que são litorâneos e ao nível do mar, tiveram registros na faixa do calor moderado no ITE máximo e de confortável no ITE mínimo. São José dos Ausentes, que apresenta a maior altitude, registrou ITE mais baixo, com índice na faixa do ligeiramente quente nas máximas e de frescor no registro das mínimas. / In summer of Rio Grande do Sul (RS) are frequent air temperature records above 30°C for a few several days, which generates a phenomenon called heat waves associated with the action of the continental tropical air mass, affecting thermal comfort and the well-being of people. This constant exchange of air masses causes extreme temperature events and interferes in the thermal comfort. Studies about thermal comfort using hourly data of RS are rare, and therefore are unknown the different thermal conditions for the sensation of thermal comfort. This study analyzed the sensation of thermal comfort and variability for nine municipalities in the RS using the Effective Temperature Index (ETI) for the summers of 2006/2007 to 2013/2014. This sensation varies in RS according to the geographical region, where it was identified three patterns of thermal comfort in the analysis of maximum and minimum ETI. The municipalities with the lowest altitude, in Porto Alegre, Santa Maria and Uruguaiana, are the most recorded thermal discomfort. The temperature range of moderate heat occurs most frequently in the maximum ETI, followed by heat range. The sensation of extreme heat have been recorded in these three municipalities. In minimum ETI, the comfortable range is predominant, followed by slightly warm. The continentality effect of Santa Maria and Uruguaiana makes these two cities the hottest places of the RS. Bento Gonçalves, Caçapava do Sul and Erechim, with altitudes of 623 m, 421 m and 777 m, respectively, recorded thermal sensation moderate heat in maximum ETI, followed by sensation slightly warm. Already the minimum correspond to the comfortable and slightly cool range. Torres and Rio Grande, which are coastal places at the sea level, had records in the range of moderate heat maximum ETI and comfortable minimum ETI. São José dos Ausentes, with the highest altitude, recorded lower ETI, with index in the range of slightly warm at maximum freshness in the record minimum.

Herbig Ae/Be (HAeBe) stars are the pre-main sequence progenitors of main sequence A and B stars, and are characterized observationally by strong emission in spectral lines and significant infra-red excess that results from their presence in dust-obscured regions. These stars are usually surrounded by a complex environment composed of gas and dust and often a significant stellar wind and a circumstellar disc. This complex circumstellar environment can have a significant affect on their spectral energy distributions, leading to large systematic uncertainties in determinations of their effective temperatures from photometric methods. In an attempt to improve temperature determinations for HAeBe stars, we have conducted an experiment to evaluate the potential of high-resolution spectra to constrain their atmospheric parameters. To this end, high-resolution (R~68 000) and low-resolution (R~1500) spectra obtained using the ESPaDOnS spectropolarimeter (at the Canada-France-Hawaii telescope) and the FORS1 spectropolarimeter (at the Very Large Telescope) have been used with an automatic spectrum fitting procedure. This procedure compares spectroscopic data to a grid of synthetic LTE, solar abundance spectra, spanning a range in effective temperature, surface gravity, and micro-turbulence. This analysis was applied to the spectra of a sample of twelve previously well-studied HAeBe stars. Our temperatures were found to be consistent with previously published values, while providing much lower uncertainties - in some cases about 5 times smaller. Numerous methods were investigated to obtain these quantitative uncertainties (chi-squared statistics, Bayesian analysis, Monte Carlo bootstrap method, individual temperature sensitive line region analysis). We conclude that our method can be used to efficiently and effectively obtain temperatures of HAeBe stars in addition to providing us with a characterization of the degree of departure of the spectrum from solar abundance, LTE photospheric models. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2009-02-13 10:23:04.9

No verão do Rio Grande do Sul (RS) são frequentes os registros de temperatura do ar acima de 30°C por alguns dias consecutivos, o que gera um fenômeno denominado de ondas de calor que associadas à atuação da massa de ar tropical continental, afetam o conforto térmico e o bem-estar das pessoas. Essa constante troca de massas de ar ocasiona extremos de temperatura e interfere no conforto térmico. Os estudos sobre o conforto térmico usando dados horários no RS são raros, e, portanto, são desconhecidas as diferentes condições térmicas para a sensação do conforto. O presente estudo analisou a sensação de conforto térmico e sua variabilidade para nove municípios do RS empregando o Índice de Temperatura Efetiva (ITE) para os verões de 2006/2007 a 2013/2014. Essa sensação varia no RS de acordo com a região geográfica, onde se identificou três padrões de conforto térmico na análise do ITE máximo e mínimo. Os municípios de menor altitude, como Porto Alegre, Santa Maria e Uruguaiana, são os que mais registraram desconforto térmico. A faixa térmica do calor moderado ocorre com maior frequência no ITE das máximas, seguido pela faixa de calor. A sensação de calor extremo é registrada nesses três municípios. No ITE das mínimas a faixa do confortável é predominante, seguida pela de ligeiramente quente. A maior continentalidade de Santa Maria e Uruguaiana faz com que esses dois municípios sejam os mais quentes do RS. Bento Gonçalves, Caçapava do Sul e Erechim, com altitudes de 623 m, 421 m e 777 m, respectivamente, registram sensação térmica de calor moderado nas máximas de ITE, seguido pela sensação de ligeiramente quente. Já as mínimas correspondem à faixa do confortável e de ligeiramente fresco. Torres e Rio Grande, que são litorâneos e ao nível do mar, tiveram registros na faixa do calor moderado no ITE máximo e de confortável no ITE mínimo. São José dos Ausentes, que apresenta a maior altitude, registrou ITE mais baixo, com índice na faixa do ligeiramente quente nas máximas e de frescor no registro das mínimas. / In summer of Rio Grande do Sul (RS) are frequent air temperature records above 30°C for a few several days, which generates a phenomenon called heat waves associated with the action of the continental tropical air mass, affecting thermal comfort and the well-being of people. This constant exchange of air masses causes extreme temperature events and interferes in the thermal comfort. Studies about thermal comfort using hourly data of RS are rare, and therefore are unknown the different thermal conditions for the sensation of thermal comfort. This study analyzed the sensation of thermal comfort and variability for nine municipalities in the RS using the Effective Temperature Index (ETI) for the summers of 2006/2007 to 2013/2014. This sensation varies in RS according to the geographical region, where it was identified three patterns of thermal comfort in the analysis of maximum and minimum ETI. The municipalities with the lowest altitude, in Porto Alegre, Santa Maria and Uruguaiana, are the most recorded thermal discomfort. The temperature range of moderate heat occurs most frequently in the maximum ETI, followed by heat range. The sensation of extreme heat have been recorded in these three municipalities. In minimum ETI, the comfortable range is predominant, followed by slightly warm. The continentality effect of Santa Maria and Uruguaiana makes these two cities the hottest places of the RS. Bento Gonçalves, Caçapava do Sul and Erechim, with altitudes of 623 m, 421 m and 777 m, respectively, recorded thermal sensation moderate heat in maximum ETI, followed by sensation slightly warm. Already the minimum correspond to the comfortable and slightly cool range. Torres and Rio Grande, which are coastal places at the sea level, had records in the range of moderate heat maximum ETI and comfortable minimum ETI. São José dos Ausentes, with the highest altitude, recorded lower ETI, with index in the range of slightly warm at maximum freshness in the record minimum.

No verão do Rio Grande do Sul (RS) são frequentes os registros de temperatura do ar acima de 30°C por alguns dias consecutivos, o que gera um fenômeno denominado de ondas de calor que associadas à atuação da massa de ar tropical continental, afetam o conforto térmico e o bem-estar das pessoas. Essa constante troca de massas de ar ocasiona extremos de temperatura e interfere no conforto térmico. Os estudos sobre o conforto térmico usando dados horários no RS são raros, e, portanto, são desconhecidas as diferentes condições térmicas para a sensação do conforto. O presente estudo analisou a sensação de conforto térmico e sua variabilidade para nove municípios do RS empregando o Índice de Temperatura Efetiva (ITE) para os verões de 2006/2007 a 2013/2014. Essa sensação varia no RS de acordo com a região geográfica, onde se identificou três padrões de conforto térmico na análise do ITE máximo e mínimo. Os municípios de menor altitude, como Porto Alegre, Santa Maria e Uruguaiana, são os que mais registraram desconforto térmico. A faixa térmica do calor moderado ocorre com maior frequência no ITE das máximas, seguido pela faixa de calor. A sensação de calor extremo é registrada nesses três municípios. No ITE das mínimas a faixa do confortável é predominante, seguida pela de ligeiramente quente. A maior continentalidade de Santa Maria e Uruguaiana faz com que esses dois municípios sejam os mais quentes do RS. Bento Gonçalves, Caçapava do Sul e Erechim, com altitudes de 623 m, 421 m e 777 m, respectivamente, registram sensação térmica de calor moderado nas máximas de ITE, seguido pela sensação de ligeiramente quente. Já as mínimas correspondem à faixa do confortável e de ligeiramente fresco. Torres e Rio Grande, que são litorâneos e ao nível do mar, tiveram registros na faixa do calor moderado no ITE máximo e de confortável no ITE mínimo. São José dos Ausentes, que apresenta a maior altitude, registrou ITE mais baixo, com índice na faixa do ligeiramente quente nas máximas e de frescor no registro das mínimas. / In summer of Rio Grande do Sul (RS) are frequent air temperature records above 30°C for a few several days, which generates a phenomenon called heat waves associated with the action of the continental tropical air mass, affecting thermal comfort and the well-being of people. This constant exchange of air masses causes extreme temperature events and interferes in the thermal comfort. Studies about thermal comfort using hourly data of RS are rare, and therefore are unknown the different thermal conditions for the sensation of thermal comfort. This study analyzed the sensation of thermal comfort and variability for nine municipalities in the RS using the Effective Temperature Index (ETI) for the summers of 2006/2007 to 2013/2014. This sensation varies in RS according to the geographical region, where it was identified three patterns of thermal comfort in the analysis of maximum and minimum ETI. The municipalities with the lowest altitude, in Porto Alegre, Santa Maria and Uruguaiana, are the most recorded thermal discomfort. The temperature range of moderate heat occurs most frequently in the maximum ETI, followed by heat range. The sensation of extreme heat have been recorded in these three municipalities. In minimum ETI, the comfortable range is predominant, followed by slightly warm. The continentality effect of Santa Maria and Uruguaiana makes these two cities the hottest places of the RS. Bento Gonçalves, Caçapava do Sul and Erechim, with altitudes of 623 m, 421 m and 777 m, respectively, recorded thermal sensation moderate heat in maximum ETI, followed by sensation slightly warm. Already the minimum correspond to the comfortable and slightly cool range. Torres and Rio Grande, which are coastal places at the sea level, had records in the range of moderate heat maximum ETI and comfortable minimum ETI. São José dos Ausentes, with the highest altitude, recorded lower ETI, with index in the range of slightly warm at maximum freshness in the record minimum.

<p>Elevated temperatures accompanying climate warming are expected to have adverse effects on sensitive lichen species. This premise was examined by measuring the sensitivity of different lichen species to elevated temperatures in the laboratory and in the field. Laboratory studies involved the exposure of nine hydrated lichen species (Xanthoparmelia austro-africana, X. hyporhytida, Xanthoparmelia sp., Xanthomaculina hottentotta, Teloschistes capensis, Ramalina sp., Flavopuntelia caperata, Lasallia papulosa, Parmotrema austrosinensis) collected from sites of different aridity and mean annual temperature for 2 hourly intervals to temperatures ranging from 24&ordm / C to 48&ordm / C in a forced daft oven and measuring their respiration rates and maximum quantum yield of PSII. Field studies involved simultaneous hourly measurements of ground surface air temperatures and Lichen effective quantum yield of PSII of hydrated lichen species populations under ambient and artificially modified environmental conditions.</p>

<p>Elevated temperatures accompanying climate warming are expected to have adverse effects on sensitive lichen species. This premise was examined by measuring the sensitivity of different lichen species to elevated temperatures in the laboratory and in the field. Laboratory studies involved the exposure of nine hydrated lichen species (Xanthoparmelia austro-africana, X. hyporhytida, Xanthoparmelia sp., Xanthomaculina hottentotta, Teloschistes capensis, Ramalina sp., Flavopuntelia caperata, Lasallia papulosa, Parmotrema austrosinensis) collected from sites of different aridity and mean annual temperature for 2 hourly intervals to temperatures ranging from 24&ordm / C to 48&ordm / C in a forced daft oven and measuring their respiration rates and maximum quantum yield of PSII. Field studies involved simultaneous hourly measurements of ground surface air temperatures and Lichen effective quantum yield of PSII of hydrated lichen species populations under ambient and artificially modified environmental conditions.</p>

Magister Scientiae (Biodiversity and Conservation Biology) / Elevated temperatures accompanying climate warming are expected to have adverse effects on sensitive lichen species. This premise was examined by measuring the sensitivity of different lichen species to elevated temperatures in the laboratory and in the field. Laboratory studies involved the exposure of nine hydrated lichen species (Xanthoparmelia austro-africana, X. hyporhytida, Xanthoparmelia sp., Xanthomaculina hottentotta, Teloschistes capensis, Ramalina sp., Flavopuntelia caperata, Lasallia papulosa, Parmotrema austrosinensis) collected from sites of different aridity and mean annual temperature for 2 hourly intervals to temperatures ranging from 24ºC to 48ºC in a forced daft oven and measuring their respiration rates and maximum quantum yield of PSII. Field studies involved simultaneous hourly measurements of ground surface air temperatures and Lichen effective quantum yield of PSII of hydrated lichen species populations under ambient and artificially modified environmental conditions. / South Africa

Ce travail propose une étude expérimentale visant à caractériser les processus dynamiques se produisant au sein de matériaux vitreux mous. La première partie présente des mesures de diffusion de traceurs nanométriques dans la Laponite (une suspension colloïdale) obtenues par une méthode de recouvrement de fluorescence (FRAP). Cette étude montre que la diffusion varie avec la concentration de Laponite et la taille du traceur. Un modèle hydrodynamique de diffusion confinée permet de décrire quantitativement les données expérimentales. Une deuxième partie concerne l’étude expérimentale du vieillissement de matériaux vitreux. Nous testons en pratique le concept théorique de température effective. Celle-ci est obtenue grâce à la technique de FRAP par la mesure simultanée de la diffusion et la convection de sondes fluorescentes dans la Laponite en cours de prise. Contrairement à certaines mesures de la littérature, le système est bien gouverné par la température ambiante. Nous présentons ensuite une étude visant à caractériser le comportement de la Laponite cisaillée. Nous avons pour cela mis au point un dispositif permettant d’appliquer un champ électrique au système, et ainsi créer des déformations locales. L’effet obtenu s’est révélé trop faible, avec d’assez grandes incertitudes (probablement liées à la complexité du système), pour être considéré comme significatif. Enfin, nous avons étudié les propriétés du Carbopol, un fluide à seuil, en mesurant sa dynamique d’ascension par capillarité. La rugosité de surface des capillaires influe énormément sur la montée du fluide. Nous montrons aussi que l’ascension est pilotée par la rhéologie du système, notamment par le seuil d’écoulement. / This work is based on an experimental analysis of the dynamical processes which occur within soft glassy materials. The first part provides measurement results of nanotracers diffusion in Laponite (a colloidal suspension) obtained by a method of fluorescence recovery (FRAP). This study shows that the diffusion is affected by the concentration of Laponite as well as the size of the tracer. A hydrodynamic model with confined diffusion allows a quantitative description of the experimental data. In a second part, an experimental study is carried out, dealing with the aging processes of glassy materials. The theoretical concept of effective temperature is probed experimentally. The effective temperature is determined using the technique of FRAP, by simultaneously measuring diffusion and convection of fluorescent probes within the aging Laponite. Contrary to some measurements found in literature, results show that the system is controlled by the bath temperature. The following study then aims at characterizing the behavior of the sheared Laponite : an experimental device is developed in this perspective, by applying an electric field to the system and thus creating local deformations. However, the observed effect appears to be too low, with relatively large uncertainties (probably linked to the complexity of the system), which impede on the significance of our results. Finally, the properties of Carbopol, a yield stress fluid, are analyzed by measuring the dynamics of capillary rise. It is shown that the surface roughness of capillary strongly affects the rise of the fluid and that the latter is controlled by the rheology of the system, and more specifically by the yield stress value.

In this thesis I investigate several aspects of local quantum criticality, a concept of key importance in a number of physical contexts ranging from critical heavy fermion compounds to quantum dot systems. Quantum critical points are associated with second order phase transitions at zero temperature. In contrast to their finite-temperature counterparts, the zero-point motion cannot be neglected near a quantum critical point. As a result, the incorporation of quantum dynamics leads to an effective dimension larger than the spatial dimension of the system for the order parameter fluctuations within the Ginzburg-Landau-Wilson treatment of criticality. This so-called quantum-to-classical mapping works well for the critical properties in insulating systems but apparently fails in systems containing gapless fermions. This has been experimentally most clearly been demonstrated within a particular class of intermetallic compounds called heavy fermions. A particular way in which the Ginzburg-Landau-Wilson paradigm fails is for critical Kondo destruction that seems to underlie the unconventional quantum criticality seen in the heavy fermions. I focus on studying the properties of critical Kondo destruction and the emergence of energy-over-temperature-scaling in systems without spatial degrees of freedom, i.e., so-called quantum impurity systems. In particular, I employ large-N techniques to address critical properties of this class of quantum phase transitions in and out of equilibrium. As quantum critical systems are characterized by a scale-invariant spectrum with many low-lying excitations, it may appear that any perturbation can lead to a response beyond the linear response regime. Understanding what governs the non-linear response regime near quantum criticality is an interesting area. Here, I first present a path integral version of the Schrieffer-Wolff transformation which relates the functional integral form of the partition function of the Anderson model to that of its effective low-energy model. The equivalence between the low-energy sector of the Anderson model in the Kondo regime and the spin-isotropic Kondo model is usually established via a canonical transformation performed on the Hamiltonian, followed by a projection. The resulting functional integral assumes the form of a spin path integral and includes a geometric phase factor, i.e. a Berry phase. The approach stresses the underlying symmetries of the model and allows for a straightforward generalization of the transformation to more involved models. As an example of the efficiency of the approach I apply it to a single electron transistor attached to ferromagnetic leads and derive the effective low-energy model of such a magnetic transistor. As Kondo screening is a local phenomenon, it and its criticality can be studied using the appropriate impurity model. A general impurity model to study critical Kondo destruction is the pseudogap Bose-Fermi Kondo model. Here, I concentrate on the multi-channel version of the model using the dynamical large-N study. This model allows to study the non-trivial interplay between two different mechanisms of critical Kondo destruction. The interplay of two processes that can each by itself lead to critical Kondo destruction. The zero-temperature residual entropy at various fixed points for the model is also discussed. The two channel Anderson model exhibits several continuous quantum phase transitions between weak- and strong-coupling phases. The non-crossing approximation (NCA) is believed to give reliable results for the standard two-channel Anderson model of a magnetic impurity in a metal. I revisit the reliability of the NCA for the standard two channel Anderson model (constant conduction electron density of states) and investigate its reliability for the two-channel pseudogap Anderson model. This is done by comparing finite-temperature, finite-frequency solutions of the NCA equations and asymptotically exact zero-temperature NCA solutions with numerical renormalization-group calculations. The phase diagram of this model is well established. The focus here will be on the dynamical scaling properties obtained within the NCA. Finally, I study the thermal and non-thermal steady state scaling functions and the steady-state dynamics of the pseudogap Kondo model. This model allows us to study the concept of effective temperatures near fully interacting as well as weak-coupling fixed points and compare the out-of-equilibrium scaling properties of critical Kondo destruction to those of the traditional spin-density wave (SDW) scenario. The differences I identify can be experimentally probed. This may be helpful in identifying the nature of the quantum critical points observed in certain heavy fermion compounds.