Dissertations / Theses on the topic 'Heat adaptation'

Thermal scavenging is a unique behavior restricted to a few desert ant genera. Workers are among the most thermotolerant land animals known to this day, being able to survive body temperatures of sometimes more than 50°C for several minutes. Making use of their remarkable heat-hardiness, they search for food in plain day, a feat that other desert creatures cannot accomplish. They mostly feed on the corpses of heat-stricken, less tolerant arthropods that were unable to survive the blazing sun of the midday desert. Thermal scavenging has evolved independently at least three times in distantly related genera, geographical well segregated inside the different deserts of the world. First, the Cataglyphis genus ranges from the Sahara Desert and extends its distribution to reach minor Asia through the Mediterranean Basin. Second the Ocymyrmex genus can be found in the Namib and Karoo deserts of southern Africa, extending its range to eastern Africa savanna plains. Finally, the Melophorus genus can be found in Australia, with thermal scavenging species distributed in the central desert of the outback region.While this impressive behavior was already well-described by the start of this PhD project, little was known about the mechanisms supporting the remarkable heat-tolerance of workers. Using biophysical and physiological approaches in Cataglyphis and Ocymyrmex, we’ve been able to pinpoint key aspects underlying stress tolerance in those genera. First, from a biophysical standpoint, the Sahara silver ant Cataglyphis bombycina is covered with a unique and dense array of prismatic hairs reflecting visible wavelengths by total internal reflection. This allows reflection of up to 50% of the incident sunlight energy, thus shifting down the ant’s thermal equilibrium and sparing its body a few critical degrees. Second, in a comparative framework, we found numerous genes involved with critical cellular processes to be constitutively expressed or strongly up-regulated to heat in thermal scavenging ants, while their orthologs were not in mesophilic species. Those processes, such as molecular chaperoning, cell-cycle regulation, energy metabolism and muscular functions are keys that allow those ants to meet the higher requirement needed to scavenge for food at both stunning speed and under extreme heat-pressure. Overall, this work investigates the physiological and biophysical basis enabling thermal scavenging ants to survive extreme heat conditions. It provides a deeper understanding of cellular heat-tolerance pathways in non-model animals and contribute to our knowledge of life’s adaptation to extreme conditions.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

Thermal adaptation in freshwater planktonic crustacean Daphnia pulex has been investigated by means of heatshock (35°C) experiments using individuals acclimated to different water temperatures (18, 24, and 28°C). Retention of mobility and survival during the heatshock experiments differed among clones and strongly depended on acclimation temperature: clones acclimated to substressful temperature (28°C) survived significantly longer than clones acclimated to lower temperatures. Both retention of mobility and survival correlated with geographic latitude of the clones' origin. There was, on the other hand, no significant correlation between clones' performance in heatshock experiments and hemoglobin content. Clones do not differ in the degree of the effect of acclimation on survival during heatshock but differ with respect to the effect of acclimation on mobility retention.

Most advice for improving physiological strain in the heat includes maintaining hydration using long-term acclimation protocols (>10 days). Therefore, the major aims of this thesis were to examine; (i) effectiveness of short term (5-day) heat acclimation (STHA) with moderately and highly trained athletes; (ii) fluid regulatory strain has a thermally-independent role in heat adaptation; and, (iii) impact of STHA on a marker of thermotolerancè (inducible heat shock protein 70; HSP70). Ten moderately trained males completed heat acclimation (Acc) under controlled hyperthermia (rectal temperature 38.5�C) for 90-min on five consecutive days (T[a] = 40�C, 60% RH), on two occasions separated by a five-week washout, in a cross-over design. One Acc was undertaken with euhydration (fluid replenishment; EUH) and one with dehydration (no fluid intake; DEH) during daily Acc bouts. Participants completed an exercising heat stress test (HST) one week before, then on the 2nd day after Acc for both regimes. HST involved cycling at 40% PPO for 90 min (T[a] = 35�C, 60% RH), 10 min rest and a ramp protocol (2% PPO each 30 s) to volitional fatigue. HSTs were further completed 1, 2, and 3 wks after Acc to track the acclimation decay. On a later occasion eight highly trained male rowers were heat acclimated under the same protocol but with DEH acclimation only and a rowing-specific HST (2000 m rowing performance test). Plasma volume (PV) at rest and cardiac output (Q̇) during HSTs were measured using CO and CO₂ rebreathing, respectively. A number of plasma constituents were measured: PV, AVP, aldosterone, HSP70, total protein, albumin, Na⁺, K⁺, Cl⁻ and osmolality. Short term heat acclimation resulted in physiological adaptation and enhanced exercise capacity for moderately trained participants. Compared to EUH permissive DEH during Acc bouts conferred larger acclimation-induced increases in resting PV by 4.1% (95%CI: -1.5 to 9.8%; p=0.06), Q̇[F]. (4.2: 0.7 to 7.8 mlmin⁻� 100 ml⁻�; p0.009), FVC (0.06: 0.02 to 0.10 ml 100ml Tissue⁻�mmHg⁻�; p=0.006), end-exercise V[s] (45.9: 3.6 to 84.4 mL; p=0.02) and decreased end-exercise f[c] by 17% (19: -29 to 9 b�min⁻�; p=0.08). Cardiovascular adaptations except PV persisted for one wk, but not two wks after Acc indicating that cardiovascular-related benefits from STHA may not be mediated by hypervolaemic responses per se. The highly trained athletes had functional heat adaptations of similar magnitude to lesser fitness-adapted participants across DEH acclimation, including resting PV expansion (4.5: 0.7 to 8.3%) and increased performance (-4.0: -6.3 to 0.6[s]; p=0.02). Plasma total protein-corrected HSP70 concentration increased from rest to end-exercise across acclimation (p=0.001). There was a greater change from rest to end-exercise on day one versus day five Acc (p=0.05), indicating a reduced stress-induced increase and a protective adaptive change. There were weak to moderate relationships between hydration indices in dynamic circumstances indicating that there is no single measure to accurately assess hydration status. In conclusion, short-term (5-day) heat acclimation was effective with adaptations more pronounced after fluid regulatory strain from a dehydration acclimation regime. Similar findings were found using highly trained and lesser- fitness adapted participants. Thermotolerance was increased by dehydration acclimation.

Dissertation presented to obtain the Ph.D. degree in Biochemistry
The accumulation of low-molecular mass organic compounds, named compatible solutes, is an efficient, widespread strategy to counterbalance increases in the external osmolarity, thereby preserving cell viability. The intracellular accumulation of compatible solutes also occurs in response to supra-optimal temperatures, and this observation led to the assumption that they play a role in the thermoadaptation process. Hyperthermophiles, organisms with optimal growth temperatures above 80ºC, have been isolated from a variety of hot habitats. Many hyperthermophiles thrive in marine geothermal areas and are slightly halophilic. As a result, they have to cope with fluctuations in the salinity of the external medium and generally accumulate compatible solutes as a defense strategy. Interestingly, these hyperthermophilic organisms show a clear preference for negatively charged solutes, such as diglycerol phosphate, di-myo-inositol 1,3’-phosphate and mannosylglycerate, over neutral or zwitterionic solutes typically found in mesophiles (glycerol, trehalose, myo-inositol, and ectoines). The question then arises whether those charged solutes were selected by organisms adapted to grow at high temperatures because they are more suitable to protect proteins and other cell components against thermal denaturation.(...)
Apoio financeiro da Fundação para a Ciência e Tecnologia e do FSE no âmbito do Quadro Comuntário de apoio, Bolsa de Doutoramento corn a referência SFRH I BD I 25539 I 2005.

The emphasis for UK dwelling refurbishment to date has centred on reducing heating energy use. However, there has been increasing evidence pointing to the need for a more holistic approach. Many existing dwellings already experience overheating during hot weather periods. Climate change projections predict increases in both the frequency and severity of extreme weather events including heat waves such as the one in August 2003, which is estimated to have claimed the lives of over 35,000 people throughout Europe, including 2,000 in the UK. Demand for housing exceeds the supply of new stock and it is estimated that over 70% of the dwellings that will be in use in 2050 have already been built. Therefore existing dwellings will require adaptation to provide more comfortable and safe environments, to reduce both summertime overheating and heating energy use. In this research, dynamic thermal simulation computer modelling was used to assess and rank the effectiveness of selected single and combined passive interventions (adaptations) on dwelling overheating during a heat wave period. Simulations were also carried out to assess the effect of those interventions on annual space heating energy use. Four distinct dwelling types were selected to represent the housing stock in London and South East England, producing seven modelling variants: 19th century end and mid-terraced houses; 1930s semi-detached house; 1960s ground, mid and top floor flats and a modern detached house. Simulations were carried out for two different occupancy profiles and four building orientations and the cost of interventions was also considered in the analysis. The first occupancy profile assumed a ‘typical’ family who left the dwellings unoccupied during the daytime, the second assumed residents who were at home all the time (e.g. elderly or infirm). Of the dwelling types studied the 1960s mid and top floor flats and the modern (2006) detached house (Tier 2) experienced more than twice as much overheating as the other dwelling types (Tier 1). Tier 2 dwellings were “harder to treat” and unlike Tier 1 dwellings their overheating exposure could not be eliminated using the selected passive interventions. It was possible to substantially reduce overheating and annual heating energy use of Tier 1 dwellings at moderate cost, whereas the costs for retrofitting Tier 2 dwellings were estimated to be many times higher. The results demonstrated that overheating exposure can be significantly greater for residents who have to stay at home during the daytime and they should not, where possible, be housed in the most vulnerable dwellings. External window shutters were found to be the single most effective intervention for overheating reduction in most of the dwelling types considered, typically resulting in a 50% reduction in overheating exposure. The exception was the 19th century terraced houses, where applying a solar reflective (high albedo) coating to the solid external walls was often more effective. In some cases the addition of insulation increased overheating and external wall insulation consistently outperformed internal wall insulation when considering the effect on overheating, though the latter could be effective as an element of combined interventions. Adaptation should therefore be considered together with mitigation, both in design practice and in regulations. If existing dwellings (for example the 19th century terraced houses) are retrofitted for energy efficiency, without considering summer use, overheating could increase dramatically. Subsequent corrective measures could be costly and energy efficiency may suffer as a result. This research builds on previous publications and research to generate systematic, quantitative and holistic guidance for retrofitting UK dwellings to reduce overheating risk during heat waves, whilst minimising annual space heating energy use and considering the cost of retrofit. An interactive retrofit advice toolkit has been developed (and made publicly available) as part of the research, which allows selection of the best performing interventions within a given budget. Recommendations for further development of the research are also suggested.

Le stress thermique résulte d'une exposition à une température située au-delà de la plage optimale pour un organisme. L’impact du stress thermique est variable selon son intensité, allant d’un effet bénéfique à la mort de l’organisme. Mon travail de thèse a établi un modèle de stress thermique aigu (aHS pour acute Heat Stress) chez C. elegans et a étudié ses effets sur l'homéostasie cellulaire, le développement des vers et la réponse autophagique. Un aHS au cours du 4ème stade larvaire induit un retard de développement, mais aucune létalité ni stérilité. Ce stress de développement entraîne la fragmentation massive mais transitoire des mitochondries, la formation d'agrégats dans la matrice et la diminution de la respiration mitochondriale. En outre, l’aHS déclenche un flux autophagique associé à des événements de mitophagie dans de nombreux tissus et en particulier dans l'épiderme. Nous avons montré que la réponse autophagique à l’aHS était protectrice pour les animaux. De plus, nous avons découvert que dans l’épiderme, les mitochondries sont les principaux sites de biogenèse des autophagosomes, en conditions physiologique et en aHS. Nous avons également constaté que la protéine DRP-1 (dynamin related protein 1) est impliquée dans le processus de mitophagie induite par l'aHS. Chez les animaux mutants drp-1 soumis au aHS, la fission mitochondriale est impossible, l’autophagie est induite mais les autophagosomes sont anormaux et agrégés sur la mitochondrie. À partir de ces données, nous proposons que DRP-1 participe au contrôle de la qualité des mitochondries stressées en coordonnant la fission mitochondriale et la biogenèse des autophagosomes. J'ai également étudié plusieurs protéines pouvant être impliquées dans les zones de contact entre le réticulum endoplasmique et les mitochondries, ainsi que leurs rôles sur la morphologie mitochondriale et l'autophagie, dans des conditions physiologiques ou d’aHS. De plus, nous avons développé de nouveaux outils pour analyser les sites de contact ER-mitochondries
Heat stress results from an exposure to a temperature beyond the optimum range of an organism. The impact of heat stress can range from beneficial to lethal due to the severity of stress. My thesis work established an acute heat stress (aHS) model in C. elegans and studied its effects on cell homeostasis, worm development and autophagy response. aHS during the 4th larval stage induces a developmental delay but no lethality or sterility. This developmental stress results in the massive but transitory fragmentation of mitochondria, the formation of aggregates in the matrix and the decrease of mitochondrial respiration. In addition, aHS triggers an active autophagy flux associated to mitophagy events in many tissues and particularly in epidermis. We showed that the autophagy response upon aHS is protective for the animals. Moreover, we discovered that in the epidermis, the mitochondria are the major sites for autophagosome biogenesis in both standard and aHS. We also found that the dynamin related protein DRP-1 is involved in aHS-induced mitophagy process. In drp-1 animals submitted to aHS, mitochondrial fission is unable to achieve, and despite autophagy induction the autophagosomes cluster and elongate abnormally on mitochondria. From these data, we propose that DRP-1 is involved in the quality control of stressed mitochondria by coordinating mitochondrial fission and autophagosomes biogenesis. I also studied several proteins which may be involved in contact zones between endoplasmic reticulum and mitochondria, and their roles on mitochondrial morphology and autophagy, in physiological or aHS conditions. Furthermore, we have developed new tools for further studying the ER-mitochondria contact sites

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.
The recent climate change has forced people to live in extreme conditions, either excessive heat or cold, implying that they must adapt to survive in these situations. However, there are people who, because of their geographical condition and lack of resources, lack the means and tools to combat these climate changes. The context of this study is provided in a rural town located in the Arequipa region (Peru), whose inhabitants have to fight against frosts of up to −20 °C in an area without electricity. A viable solution to this problem is found through the design and implementation of a heating system using geothermal and photovoltaic energy, which are resources found in the area, according to a report of the Ministry of Energy and Mines. This study analyzes and researches the geographical and meteorological conditions of the region, for validating, through theory and simulations, whether the proposed system can supply the thermal energy required to maintain the indoor temperature at a minimum of 15 °C under extreme conditions. The system is designed after analyzing the best technological options and techniques currently available in the context studied for its ultimate financing and establishing guidelines and indicators for monitoring results.

Human interference with the Earth’s climate, through the release of greenhouse gasses (GHGs), is estimated to have already increased average statewide temperatures in California by 1.7° Fahrenheit (F), with a further 2.7°F of warming expected by mid-century. The negative impacts of increased temperatures may be especially acute in mid-latitude cities that currently enjoy a mild climate, such as Los Angeles (LA), which are projected to warm to a point that will significantly affect human health and well being. The built environment increases urban temperatures through building materials that readily absorb heat from the sun, a lack of vegetation, a lack of pervious surface area, and anthropogenic heat. Local governments can take action to help their cities adapt to future temperatures through changes to building materials, urban design and infrastructure. This study evaluates six urban design strategies for reducing temperatures and therefore adapting to increased heat in LA: cool roofs, cool pavements, solar panels, tree planting, structural shading and green roofs. The methods used in this analysis include a cost-effectiveness analysis, key stakeholder interviews, and case studies from other cities in the US. Findings indicate that cool roofs are the most cost-effective strategy for urban heat island mitigation, with cool pavements and tree planting also cost-effective. Findings from stakeholder interviews indicate that political feasibility is high for all strategies except structural shading, which was thought to be costly and difficult to implement. However, significant political barriers were also identified for tree planting and green roofs. Findings from four case studies indicate that climate adaptation policies should emphasize co-benefits, include flexible design standards, and provide financial or performance-based incentives for property owners or developers. Specific recommendations for implementing climate adaptation measures are provided for urban planners, policy makers, urban designers and architects in Los Angeles.

Shale barrens are unique habitats located throughout the southern Appalachians. They are characterized by a south or south west aspect, a steep slope, and an exposed rocky surface (Platt, 1951). They have a high total irradiance and can experience temperatures higher than the surrounding deciduous forest. A variety of plant species, several of which are rare or endangered, are endemic to the shale barren habitat. One reason proposed fc)r their endemism is that the plants are obligate heliophyt:es (Keener, 1983). The purpose of this dissertation is tel examine the acclimation ability of the shale barren endemic Eriogonum alIeni to shade and high temperature.
Ph. D.

Climate resilience is increasingly an attribute of competitive global cities. Cities that are most responsive to change will continue to prosper. To achieve this, governance structures and decision-making approaches that promote flexible and/or robust adaptation action are required. This thesis introduces a framework for urban adaptation planning that links medium-term risk management with the development and appraisal of long-term adaptation pathways. A long-term plan informed by the appraisal of a range of plausible pathways provides the opportunity to retain the flexibility to respond to future uncertainties, whilst also demonstrating how a city could manage future climate risk. This provides stakeholders with confidence that long-term risk is adequately considered, even if there is not a need to act immediately. To demonstrate how adaptation pathways can support adaptation decision-making in an urban system, the approach and methods developed as part of this thesis are applied in London. Adaptation pathways in response to water scarcity, surface water flood and heat risk were developed, and their appraisal presented as pathways diagrams. These diagrams provide a visual representation of the sequencing of decision points and plausible adaptation actions that may be implemented in the future. Pathways diagrams present climate risk and adaptation information for decision-makers in a salient and actionable manner. The pathways responding to individual risks in London are then brought together to demonstrate how an integrated assessment framework may be used to appraise city-scale adaptation pathways that respond to multiple climate risks. The growing emphasis within adaptation planning on approaches that can react flexibly to change increases the need to better understand the dynamics of climate risk and embed learning about the effectiveness of adaptation actions. To complement the pathways and adaptation decision-making research presented in this thesis, a framework that links adaptation monitoring and evaluation (M&E), risk assessment and decision-making is presented and explored to highlight the potential benefits of, and mechanisms for, adaptation M&E to inform and strengthen iterative risk-based adaptation planning. Demonstrated for the Thames Estuary, where concepts of adaptation planning have been pioneered but the opportunities of linking to monitoring and evaluation have not been extensively explored, we show how the framework can highlight actions and factors that are contributing to improving adaptation outcomes and those that require strengthening. This thesis contributes to the literature on urban climate change adaptation planning under conditions of uncertainty. This thesis also contributes to the evidence base needed to justify long-term planning and realise the benefits of climate risk reduction through the implementation of flexible, long-term integrated urban adaptation plans.

The heat demand in Sweden has stagnated and district heating companies must take action to sustain in the market. Based on this background this study combines a PEST and SWOT analysis to produce a basis to suggest general strategies suitable for district heating companies in southern Sweden. The analysis found that both investments into activities outside of the heating market, as well as further development of current systems, are viable options. Increasing the awareness and knowledge about district heating companies was also identified as a factor that could entail several benefits.

The Heat Shock Protein 90 (Hsp90) is an essential and highly conserved chaperone that facilitates the maturation of a wide array of client proteins, including many kinases. These clients in turn regulate a wide array of cellular processes, such as signal transduction, and transcriptional reprogramming. As a result, the activity of Hsp90 has the potential to influence physiology, which in turn may influence the ability to adapt to new environments. Previous studies using a deep mutational scanning approach, (EMPIRIC) identified multiple substitutions within a 9 amino acid substrate-binding loop of yeast Hsp90 that provides a growth advantage for yeast under elevated salinity conditions and costs of adaptation under alternate environments. These results demonstrate that genetic alterations to a small region of Hsp90 can contribute to evolutionary change and promote adaptation to specific environments. However, because Hsp90 is a large, highly dynamic and multi-functional protein the adaptive potential and evolutionary constraints of Hsp90 across diverse environments requires further investigation. In this dissertation I used a modified version of EMPIRIC to examine the impact of environmental stress on the adaptive potential, costs and evolutionary constraints for a 118 amino acid functional region of the middle domain of yeast Hsp90 under endogenous expression levels and the entire Hsp90 protein sequence under low expression levels. Endogenous Hsp90 expression levels were used to observe how environment may affect Hsp90 mutant fitness effects in nature, while low expression levels were used as a sensitive readout of Hsp90 function and fitness. In general, I found that mutations within the middle domain of Hsp90 have similar fitness effects across many environments, whereas, under low Hsp90 expression I found that the fitness effects of Hsp90 mutants differed between environments. Under individual conditions multiple variants provided a growth advantage, however these variants exhibited growth defects in other environments, indicating costs of adaptation. When comparing experimental results to 261 extant eukaryotic sequences I find that natural variants of Hsp90 support growth in all environments. I identified protein regions that are enriched in beneficial, deleterious and costly mutations that coincides with residues involved in co-chaperone-client-binding interactions, stabilization of Hsp90 client-binding interfaces, stabilization of Hsp90 interdomains and ATPase chaperone activity. In summary, this thesis uncovers the adaptive potential, costs of adaptation and evolutionary constraints of Hsp90 mutations across several environments. These results complement and extend known structural and functional information, highlighting potential adaptive mechanisms. Furthermore, this work elucidates the impact environment can have on shaping Hsp90 evolution and suggests that fluctuating environments may have played a role in the long-term evolution of Hsp90.

L'objet de ce travail est l'analyse mathématique et numérique d'un critère de maillage au voisinage de l'interface entre deux milieux pour un problème de transfert thermique. Nous caractérisons son domaine de validité pour diverses méthodes d'approximation numérique et nous établissons le lien avec les techniques usuelles de maillage adaptatif. Une première analyse montre que le critère est efficace sur certains schémas monodimensionnels aux différences finies à trois points en espace et qu'il se traduit par une amélioration de l'erreur de consistance au point interface. Dans le cadre de la méthode aux éléments finis de degré un, nous montrons que le critère coïncide avec celui classique d'equirepartition de la norme l#2 de l'erreur d'interpolation. Par contre, pour d'autres normes, en particulier la norme énergie, l'analyse conduit à des critères différents. Ensuite, nous situons le critère par rapport aux estimations a posteriori faites en maillage adaptatif pour des estimateurs équivalents à la norme énergie de l'erreur. Des simulations numériques illustrent tous ces aspects en dimension un et deux

Ce manuscrit s'intéresse à l'arrosage urbain en tant que stratégie de rafraîchissement pour les villes souhaitant réduire l'intensité de leur îlot de chaleur urbain (ICU) et/ou en tant qu'outil d'adaptation aux canicules, amenées à devenir plus fréquentes et intenses en raison du changement climatique. Cette recherche s'appuie sur une expérimentation d'arrosage réalisée à Paris (France) sur deux sites pendant les étés 2013 et 2014. D'abord, une méthode d'analyse a été mise au point afin de déterminer les effets micro-climatiques de l'arrosage sur le terrain. La température de l'air, l'humidité relative et la température moyenne de rayonnement ont été examinées ainsi que le confort thermique du piéton grâce au Universal Thermal Climate Index et le pouvoir d'atténuation de l'ICU. Ensuite, les effets thermiques ont été quantifiés, comprenant les effets sur la température de surface ainsi que le flux de chaleur et la température à 5 cm de profondeur. Enfin, la consommation d'eau de l'arrosage a été estimée à partir d'une relation linéaire trouvée entre le flux de chaleur à 5 cm de profondeur et le rayonnement solaire incident pendant la période d'ensoleillement direct. Par ailleurs, des améliorations de la méthode d'arrosage ont été déterminées et discutées. Les analyses conduites ici fournissent des informations essentielles pour les décideurs intéressé! par l'arrosage urbain comme volet de leur stratégie de réduction des ICUs et/ou d'adaptation aux canicules. Les recherches à venir devraient s'orienter sur l'impact d'autres matériaux et configurations urbaines sur l'arrosage ainsi que les effets cumulés atteints lorsqu'un quartier entier est arrosé plutôt qu'une portion de rue. Certaines modifications de la méthode méritent également d'être étudiées
This dissertation examines pavement-watering as a cooling strategy for cities seeking to reduce the intensity of their urban heat island (UHI) and/or as an adaptation tool against increasing heat wave frequency and intensity resulting from climate change. This research is based on measurements obtained from a field experiment of pavement-watering conducted at two sites ir Paris, France over the summers of 2013 and 2014. First, an analysis method was developed to determine the method's microclimatic effects in the field. Air temperature, relative humidity and mean radiant temperature effects were investigatec as well as pedestrian thermal comfort using the Universal Thermal Climate Index and UHI-mitigation. Second, the thermal effects of pavement-watering were determined, including surface temperature as well as pavement heat flux and temperature 5 cm deep. Finally, the water footprint of pavement-watering was determined based on a linear relationship found between pavement heat flux and solar irradiance. In addition, possible improvements for the watering method were determined and discussed. The research provides useful information for decision-makers considering pavement-watering as part of their heat-wave adaptation and/or UHI-mitigation strategy. Future work should focus on the effects of different materials and street configurations on pavement-watering cooling as well as cumulative effects arising from watering large areas rather than a single street portion. Certain methodological aspects also require further investigation and may be improved

Global climate change is anticipated to raise the overall temperatures and is likely to increase future mortality attributable to heat. Predicting future health consequences of higher temperatures at the regional, national and global level based on historical temperature-mortality relationships can be challenging due in part to the uncertainties in the location-specific temperature-mortality relationship, the heat threshold, and how populations will adapt or acclimatize. This study reviews published estimates of the warm season temperature-mortality relationships around the world and explores the heterogeneity in terms of the magnitude of the relationship and the threshold. We also investigate the potential effects of adaptation and acclimatization on the estimates of excess heat-related deaths based on empirical evidence, and propose a method that can be used in future projections to address the uncertainties. This study contributes to the literature of projecting the future public health burden of heat-related effects, which provides valuable information to climate policy decision making.

Orientador: Renato Luis Furlan
Banca: Daniel Emygdio de Faria Filho
Banca: Otto Mack Junqueira
Resumo: Com o objetivo de avaliar a real eficácia do condicionamento térmico precoce em condições de campo, bem como elucidar as respostas adaptativas relacionadas à maior tolerância ao calor, 600 pintainhos de corte machos, da linhagem Cobb-500® , foram distribuídos em um delineamento inteiramente casualizado em esquema fatorial 2X2, sendo os fatores processo de adaptação ao calor (controle e condicionamento térmico) e programa de luz (contínuo e intermitente). Aves condicionadas ao calor ou expostas à luminosidade intermitente ingeriram maior quantidade de água durante todo período de desafio térmico; no entanto, somente o programa de fornecimento intermitente de luz foi eficiente em reduzir a mortalidade final das aves. De fato, frangos submetidos à luminosidade intermitente apresentaram menor relação heterófilo: linfócito ao final do período de criação e ainda concentração plasmática de T4 e temperatura interna menores no início do período de estresse térmico. Frangos condicionados ao calor não apresentaram alteração na composição química da carcaça; porém, a deposição protéica das aves submetidas ao programa de fornecimento intermitente de luminosidade foi reduzida. Tais resultados evidenciam aparente ineficácia do processo de condicionamento térmico precoce em reverter os efeitos deletérios da exposição crônica e cíclica ao calor na fase final de criação. Entretanto, a adoção de um programa de fornecimento intermitente de luminosidade mostrou-se benéfica à maximização da tolerância das aves ao calor.
Abstract: In order to evaluate the real efficacy of early age thermal conditioning in field conditions and clarify the physiological responses related to greater heat tolerance, 600 male broiler chicks were distributed in a 2X2 factorial design, with the factors - heat adaptation (control and heat conditioning) and light schedule (continuous and intermittent). Heat-conditioned and intermittent-lightexposed broilers drank more water during the final week of experiment; however, only the intermittent light program reduced flock mortality level significantly. In fact, intermittent-light-exposed broilers showed lower T4 plasmatic concentration and body temperature at the beginning of the heat-stress period and reduced heterophil to linfocyte ratio at the end of thermal challenge. Their carcass protein deposition at 42 days was decreased too. These results allow concluding that early age thermal conditioning seems to be inefficient on reducing the impact of chronic and cyclical heat exposure at marketing age. However, intermittent light program improve broiler heat tolerance.
Mestre

Ce manuscrit s’intéresse à l’arrosage urbain comme stratégie d’atténuation de la chaleur et d’adaptation au changement climatique. La méthode est optimisée pour des matériaux de voirie traditionnels et "frais" afin de limiter la consommation d’eau du procédé. La première partie de ce manuscrit utilise des mesures de terrain recueillies lors de campagnes d’arrosage à Paris entre 2013 et 2018. Une méthode d’analyse statistique permet de déterminer les effets microclimatiques de l’arrosage sur la température de l’air et le stress thermique à l’aide de l’Indice Universel de Climat Thermique. Deux protocoles d’arrosage sont comparés afin de déterminer l’influence de la surface arrosée sur l’efficacité de la méthode.Dans un second temps, une expérience de laboratoire est utilisée afin de comparer le comportement thermique de structures de voirie réalistes dans des conditions similaires à celles d’une vague de chaleur parisienne. L’échantillon subit un cycle climatique de 24 heures et son arrosage peut être activé à une fréquence fixe. A l’aide de mesures de température et de flux thermique en surface et en profondeur, le bilan thermique de surface permet de déterminer le flux rafraîchissant évaporatif pour chaque débit d’arrosage testé. Les résultats obtenus sur une structure de chaussée en asphalte sont comparés à ceux du terrain.Enfin, le protocole est appliqué à douze revêtements traditionnels et "frais", avec et sans arrosage. L’arrosage est optimisé pour chaque structure afin de maximiser le rafraîchissement en minimisant la consommation d’eau. Pour ce faire, deux régimes de rafraîchissement sont employés. Les paramètres déterminants dans l’optimisation du flux rafraîchissant selon le débit sont identifiés. Le bilan thermique de la surface et le partitionnement de l’irradiance sont analysés pour chaque échantillon. L’efficacité de la méthode selon les structures ainsi que les limites du protocole de laboratoire sont discutées.Ce travail vise à fournir des informations utiles aux décideurs qui envisagent l’emploi de l’arrosage urbain ou de revêtements "frais" dans leur stratégie d’atténuation de la chaleur. La recherche future devrait s’intéresser aux effets microclimatiques de revêtements "frais" en combinaison avec de l’arrosage afin de confronter les résultats de laboratoire à davantage d’études de terrain. Ces dernières devront proposer un plan expérimental adéquat, tandis que les méthodes d’analyse statistique associées pourront également faire l’objet de futures améliorations
This manuscript examines the use of pavement-watering as a heat mitigation strategy and climate change adaptation tool for cities. The method is fine-tuned for traditional and cool paving materials in order to limit the water footprint of the technique. The first Part of this research is based on field measurements gathered form watering campaigns in Paris from 2013 to 2018. A suited statistical analysis method is proposed in order to determine the microclimatic effects of watering, including effects on air temperature and pedestrian thermal stress using the Universal Thermal Climate Index. Two watering protocols are compared to determine the influence of the surface area being watered on the efficiency and duration of pavement-watering.Secondly, a laboratory experiment is used to compare the thermal behaviour of realistic paving structures under heat-wave like conditions. The pavement undergoes a 24-h climate cycle and watering can be enabled at a fixed frequency. On the basis of surface and in-depth temperature and heat flux measurements, using the surface heat budget, the evaporative cooling flux is determined for each tested watering rate. Results obtained on an asphalt road structure with the lab protocol are compared to field results. Finally, the lab protocol is applied to twelve traditional and cool pavements under dry and watered conditions. Watering is fine-tuned for each structure to maximize cooling and minimize the water consumption using two linear cooling regimes. Driving parameters influencing the optimization of the evaporative cooling versus the watering rate are determined. The surface heat budget and the partitioning of irradiance into conductive, convective, radiative and cooling fluxes are analysed for each paving structure. In the end, the benefits of each pavement, the efficiency of the method and the limitations of the lab protocol are discussed.This research intends to provide useful information for decision-makers considering the use of pavement-watering or cool pavements as heat mitigation strategy. Future work should principally investigate the microclimatic effects of cool pavements combined with pavement-watering to confront lab results to field studies. Those should come with an adapted experimental design, while associated statistical procedures may also require improvements in the future

We miss summer time during winter especially when it snows heavily resulting in cancelation of classes but we turn to ignore high temperature and its associated health impacts during summer. Several studies have shown that high temperatures during summer are associated with morbidity and mortality in many cities in the United States over the past decade. Gradual increase in temperature over the past years raises public health concerns about the impacts of heat on human health in future and the role of adaptation. Our study aimed at assessing future heat-related mortality due to climate change in the United States. We hypothesized that incidence of premature death will increase with future temperature rise and population adaptation will reduce the mortality rate. We reviewed research articles on temperature-related premature death. The literature search was limited to studies conducted in United States and seven studies which demonstrated positive association between temperature and premature death were selected for this study. We predicted future high temperature-related mortality using BenMap benefit model designed to estimate 2015 Appalachian Student Research Forum Page 111 air pollution impacts on public health. Based on the selected studies, BenMap model projected 2020-2050 temperature scenario using modeled daily mean apparent temperature to estimate future heat-related mortality. Our results showed that high temperatures would cause an increase in heat-related mortality and adaptation would minimize the effects of climate change as people get used to high temperatures. The outcome of our study confirms the positive association between high temperature and mortality which emphasizes the need for policy makers to take appropriate actions such as greenhouse gas emission reduction to protect public health.

Foodborne illnesses caused by Listeria monocytogenes have long been associated with ready-to-eat (RTE) meats contaminated after the primary thermal process has been applied. It is believed that brine solutions used to chill cooked RTE products may serve as a reservoir for L. monocytogenes becoming a potential point of post-processing contamination for RTE meats. Re-circulating ultraviolet light (UV) systems are being used to inactivate L. monocytogenes in chill brines; however very little has been reported on the dose response of healthy and stressed L. monocytogenes to UV in brine solutions. The objectives of this research were to determine 1) minimum dose of UV required to inactivate L. monocytogenes in distilled water, fresh brine, undiluted spent brine, and diluted spent brine, 2) if adaptation to food processing stresses affects the dose response, and 3) if the acquisition of antibiotic resistance mechanisms provides resistance to ultraviolet light 4) effect of stress adaptation on survival in brine solutions. After UV exposure, populations were reduced as follows from greatest to least: water > fresh brine > 5% spent brine > 35% spent brine > 55% spent brine > 100% spent brine (P â ¤ 0.05). There were no population differences between acid stressed and antibiotic resistant or healthy and heat shocked (P > 0.05). However, acid-stressed and sulfanilamide-resistant were more resistant to UV light than healthy and heat shocked L. monocytogenes (P â ¤ 0.05). Survival in brine solutions (no UV) followed the trend, from greatest to least (P â ¤ 0.05): sulfanilamide-resistant > acid-stressed > healthy > heat-shocked. Population estimates decreased from initial inoculation to final sampling for each cell type suspended in spent brine (P â ¤ 0.05), but only healthy and heat- shocked cells suspended in fresh brine were significantly reduced (P â ¤ 0.05). Knowledge of UV dosing required to control L. monocytogenes in brines used during RTE meat processing, and a greater understanding of the interactions that may influence dose will aid manufacturers in establishing appropriate food safety interventions for these products.
Ph. D.

Urban populations worldwide are expanding rapidly and consequently a large number of people are becoming exposed to hazards inherent in cites. Phenomena such as the urban heat island can exacerbate the effects of heatwaves, and land surface sealing can lead to flash flooding. Cities are also the sites of enhanced air and water pollution from non-point sources such as concentrated motor vehicle use. Climate change predictions for the UK include increased winter precipitation and an increase in frequency of summer heatwaves. This will put further pressure on urban residents and infrastructure. Roof greening can be used within climate change adaptation schemes because green roofs have a range of environmental benefits which can help urban infrastructure become more sustainable. This thesis empirically quantifies several of these benefits, and the processes influencing them, by monitoring real green roofs in Manchester. A number of novel discoveries were made. Green roofs act as passive filters of airborne particulate matter. 0.21 tonnes of PM10 (2.3% of the inputs) could be removed from Manchester city centre in a maximum extensive green roof scenario. Species and site differences in particle capture were exhibited and related to morphology and proximity to sources respectively. An intensive green roof was able to lower the monthly median overlying air temperature at 300 mm by up to 1.06 oC. A combination of drought and mismanagement caused damage to the vegetation on one of the green roofs, with a subsequent reduction in the cooling effect. Daytime air temperatures were higher than over an adjacent bare roof for a larger proportion of the day than over the undamaged roof, and lower cooling was observed at night. A site-specific methodology was devised to monitor the rainwater runoff from an intensive green roof and an adjacent bare roof. Average runoff retention of 65.7% was observed on the green roof, compared to 33.6% on the bare roof. Season and rainfall amount had significant impacts on retention, however, many other explanatory variables such as Antecedent Dry Weather Period (ADWP) and peak rainfall intensity had no demonstrable, significant impact. Intensive roof construction on 10% of the rooftops in Manchester city centre would increase annual rainfall retention by 2.3%. The runoff was characterised with regards to heavy metals and nutrients. Nutrient levels were found to be not a significant problem for water quality, however, Environmental Quality Standards (EQS) values for protection of freshwater were exceeded for concentrations of Cu, Pb and Zn. High metal concentrations within the sediments may be acting as sources of pollution, particularly in the case of Pb. The age of the green roof means that past atmospheric deposition of Pb could be contributing to the runoff quality. The multi-benefit aspect of green roofs is discussed in the light of the results of this thesis and recommendations made for policy makers and the green roof construction industry.

Climate change effects are getting more evident year by year. Athens is specially affected by climate change related shocks, especially by poor air quality, flooding and heat waves. Every year climate shocks threatens and worsens the situation in the city. The municipality of Athens, together with the European Investment Bank and EQO-NIXUS (consulting company) have undertaken a project in order to increase the resilience and the mitigation and adaptation measures of the city, taking as case study 5 public buildings located in different areas of the centre of the city. This project is in line with the Athens Resilience Strategy drawn by the Municipality of Athens in order to integrate new ways to prepare and protect the city from future shocks and stresses. This study aims to investigate and propose mitigation and adaptation measures that could be potentially applied into the 5 selected public buildings in order to improve the energy efficiency and the resilience towards heat waves, flooding and pollution of the air. A literature review study has been performed in order to look for good practices worldwide in terms of energy efficiency and climate mitigation and adaptation in order to find the best measures that could be applied in the 5 selected buildings. Finally, a multi-criteria decision analysis has been executed to prioritise which measures result to be more relevant for each specific building. The study shows that, in overall, energy efficiency and raise of public awareness are the most relevant measures that can be potentially applied in the buildings in order to tackle the climate shocks that threatens Athens. Finally, if the measures are applied into the buildings and the resilience and energy efficiency measures are improved, this study could be replicated to other buildings of Athens in order to achieve the 2030 strategy plan set by the municipality of Athens.
Effekterna av klimatförändringen blir alltmer tydliga. Greklands huvudstad Aten påverkas exempelvis av försämrad luftkvalitet, översvämningar och värmeböljor och extrema klimatrelaterade händelser förvärrar situationen i staden. Atens kommun har tillsammans med Europeiska investeringsbanken och EQO-NIXUS (ett privat konsultföretag) genomfört ett projekt för att öka motståndskraften mot klimatförändringens effekter, genom anpassningsåtgärder, där fem offentliga byggnader i olika delar av Atens centrum studeras. Projektet är relaterat till Atens resiliensstrategi som handlar om hur staden ska integrera nya sätt förbereda och skydda staden och dess invånare från framtida extrema händelser och påfrestningar. Denna studie syftar till att undersöka och föreslå anpassningsåtgärder som potentiellt kan tillämpas i de fem olika offentliga byggnaderna för att förbättra energieffektiviteten och resiliensen mot värmeböljor, översvämningar och luftföroreningar. En litteraturstudie har genomförts för att identifiera globala, goda exempel när det gäller energieffektivitet och anpassning till ett förändrat klimat som potentiellt kan tillämpas i de fem byggnaderna. Slutligen har en multikriterieanalys med flera kriterier genomförts för att prioritera vilka åtgärder som är mest relevanta för varje specifik byggnad. Studien visar att energieffektivitet och ökning av allmänhetens medvetenhet totalt sett är de mest relevanta åtgärderna som potentiellt kan tillämpas i byggnaderna för att hantera klimatförändringar. Slutligen, om dessa åtgärder tillämpas och resiliensen och energieffektivitetsåtgärderna förbättras, skulle denna studie kunna vara relevant även för andra byggnader i Aten och därmed bidra till uppfyllelsen av stadens 2030-strategi.

La température est le paramètre abiotique qui influence de façon majoritaire les traits d’histoire de vie des espèces ectothermes. Pour appréhender les relations entre physiologie, environnement et histoire évolutive et leur influence respective sur la délimitation des aires de distribution des espèces, ce travail exploite les caractéristiques thermiques du milieu souterrain. Les résultats réfutent l’hypothèse de sténothermie des deux organismes hypogés étudiés Niphargus rhenorhodanensis et Proasellus valdensis et prouvent que l’histoire évolutive, la dispersion ou la compétition sont des paramètres importants dans l’établissement des aires de distribution des espèces souterraines. En outre, ce travail caractérise pour la première fois chez des organismes souterrains, un gène codant pour des protéines de choc thermique et montre l’importante sensibilité cellulaire de N. rhenorhodanensis face à une augmentation de température
Temperature is the abiotic factor that most influences the life-history traits of ectothermic organisms. In order to study the relationships between physiology, environment and evolutionary history and their respective role in the determination of species distribution areas, this work takes advantage of the thermal caracteristics of subterranean aquatic biotopes. Our results refuted stenothermy in both studied hypogean organisms Niphargus rhenorhodanensis and Proasellus valdensis and they showed that evolutionary history, dispersal and competition are important factors that determine the distribution of subterranean species. Moreover, this work characterized for the first time in subterranean organisms a gene encoding heat shock proteins and demonstrated the high cellular sensitivity of N. rhenorhodanensis to increased water temperature

L'interaction fluide structure est présente dans beaucoup de problèmes industriels, dans les domaines d'ingénierie mécanique, civile ou biomécanique. Même si les performances informatiques s'améliorent considérablement et que les méthodes en mécanique numérique gagnent en maturité, certaines difficultés ne permettent pas encore de réaliser des simulations numériques précises. Actuellement deux méthodes numériques gagnent en popularité pour la simulation numérique d'interactions fluide structure: la méthode de partitionnement et la méthode monolithique. Des résultats de la littérature montrent que la première est efficace et précise mais qu'elle peut rencontrer des problèmes d'instabilité si les ratios de densité sont élevés ou que les géométries sont complexes. Les méthodes d'immersion sont de plus en plus utilisées par la communauté scientifique. Différentes approches ont été développées, dont la Méthode d'Immersion de Volume. Cette méthode permet de faciliter la mise en place des calculs. Ainsi il n'est pas nécessaire de construire des maillages concordant avec la géométrie des objets, et le couplage entre les fluides et les solides se fait naturellement. C'est sur cette analyse qu'a été développé le logiciel Thost. Il permet de simuler des procédés industriels tels que le chauffage de pièces métalliques dans les fours industriels ou la trempe sans caractériser expérimentalement des coefficients de transfert. Le but d'un tel logiciel est de permettre une meilleure compréhension des procédés et ainsi de les optimiser. Cependant les coûts de calcul restant élevés, le but de la thèse est de les diminuer en s'appuyant sur des méthodes numériques innovantes tels que l'adaptation dynamique de maillage anisotrope, des méthodes éléments finis stabilisées ou l'immersion directe des objets à partir de la Conception Assistée par Ordinateur
Fluid-Structure Interaction (FSI) describes a wide variety of industrial problems arising in mechanical engineering, civil engineering and biomechanics. In spite of the available computer performance and the actual maturity of computational fluid dynamics and computational structural dynamics, several key issues still prevent accurate FSI simulations.Two main approaches for the simulation of FSI problems are still gaining attention lately: partitioned and monolithic approaches. Results in the literature show that the partitioned approach is accurate and efficient but some instabilities may occur depending on the ratio of the densities and the complexity of the geometry. Monolithic methods are still of interest due to their capability to treat the interaction of the fluid and the structure using a unified formulation. In fact it makes the build up of a FSI problem easier as the mesh do not have to fit the geometry of the solids and the transfers are treated naturally.The software Thost has been created based on these analyzes. Thost is a 3D aerothermal numerical software. It has been developped for the numerical simulation of industrial processes like the heating in industrial furnaces as well as quenching. Its target is to model numericaly the thermal history of the industrial pieces in their environment without using any transfer coefficient. However the computational costs are still high and therefore the software is not fully efficient from an industrial point of view to simulate, analize and improve complex processes. All the work in this PhD thesis has been done to reduce the computational costs and optimize the accuracy of the simulations in Thost based on innovatives numerical methods such as dynamic anisotropic mesh adaptation, stabilized finite elements methods and immersing the objects directly from their Computer Aided Design files

Aujourd'hui, avec l'amélioration des puissances de calcul informatique, la simulation numérique est devenue un outil essentiel pour la prédiction des phénomènes physiques et l'optimisation des procédés industriels. La modélisation de ces phénomènes pose des difficultés scientifiques car leur résolution implique des temps de calcul très longs malgré l'utilisation d'importantes ressources informatiques.Dans cette thèse, on s'intéresse à la résolution de problèmes complexes couplant écoulements et transferts thermiques. Les problèmes physiques étant fortement anisotropes, il est nécessaire d'avoir un maillage avec une résolution très élevée pour obtenir un bon niveau de précision. Cela implique de longs temps de calcul. Ainsi il faut trouver un compromis entre précision et efficacité. Le développement de méthodes d'adaptation en temps et en espace est motivé par la volonté de faire des applications réelles et de limiter les inconvénients inhérents aux méthodes de résolution non adaptatives en terme de précision et d'efficacité. La résolution de problèmes multi-échelles instationnaires sur un maillage uniforme avec un nombre de degrés de liberté limité est souvent incapable de capturer les petites échelles, nécessite des temps de calcul longs et peut aboutir à des résultats incorrects. Ces difficultés ont motivé le développement de méthodes de raffinement local avec une meilleure précision aux endroits adéquats. L'adaptation en temps et en espace peut donc être considérée comme une composante essentielle de ces méthodes.L'approche choisie dans cette thèse consiste en l'utilisation de méthodes éléments finis stabilisées et le développement d'outils d'adaptation espace-temps pour améliorer la précision et l'efficacité des simulations numériques.Le développement de la méthode adaptative est basé sur un estimateur d'erreur sur les arrêtes du maillage afin de localiser les régions du domaine de calcul présentant de forts gradients ainsi que les couches limites. Ensuite une métrique décrivant la taille de maille en chaque noeud dans les différentes directions est calculée. Afin d'améliorer l'efficacité des calculs la construction de cette métrique prend en compte un nombre fixe de noeuds et aboutit à une répartition et une orientation optimale des éléments du maillage. Cette approche est étendue à une formulation espace-temps où les maillages et les pas de temps optimaux sont prédits sur des intervalles de temps en vue de contrôler l'erreur d'interpolation sur la domaine de calcul
Nowadays, with the increase in computational power, numerical modeling has become an intrinsic tool for predicting physical phenomena and developing engineering designs. The modeling of these phenomena poses scientific complexities the resolution of which requires considerable computational resources and long lasting calculations.In this thesis, we are interested in the resolution of complex long time and large scale heat transfer and fluid flow problems. When the physical phenomena exhibit sharp anisotropic features, a good level of accuracy requires a high mesh resolution, hence hindering the efficiency of the simulation. Therefore a compromise between accuracy and efficiency shall be adopted. The development of space and time adaptive adaptation techniques was motivated by the desire to devise realistic configurations and to limit the shortcomings of the traditional non-adaptive resolutions in terms of lack of solution's accuracy and computational efficiency. Indeed, the resolution of unsteady problems with multi-scale features on a prescribed uniform mesh with a limited number of degrees of freedom often fails to capture the fine scale physical features, have excessive computational cost and might produce incorrect results. These difficulties brought forth investigations towards generating meshes with local refinements where higher resolution was needed. Space and time adaptations can thus be regarded as essential ingredients in this recipe.The approach followed in this work consists in applying stabilized finite element methods and the development of space and time adaptive tools to enhance the accuracy and efficiency of the numerical simulations.The derivation process starts with an edge-based error estimation for locating the regions, in the computational domain, presenting sharp gradients, inner and boundary layers. This is followed by the construction of nodal metric tensors that prescribe, at each node in the spatial mesh, mesh sizes and the directions along which these sizes are to be imposed. In order to improve the efficiency of computations, this construction takes into account a fixed number of nodes and generates an optimal distribution and orientation of the mesh elements. The approach is extended to a space-time adaptation framework, whereby optimal meshes and time-step sizes for slabs of time are constructed in the view of controlling the global interpolation error over the computation domain

Made available in DSpace on 2014-06-11T19:28:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-07-29Bitstream added on 2014-06-13T18:57:30Z : No. of bitstreams: 1 vieira_bs_me_jabo.pdf: 210260 bytes, checksum: d3afaa3f53192340812b4ef7563a72a4 (MD5)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Com o objetivo de avaliar a real eficácia do condicionamento térmico precoce em condições de campo, bem como elucidar as respostas adaptativas relacionadas à maior tolerância ao calor, 600 pintainhos de corte machos, da linhagem Cobb-500® , foram distribuídos em um delineamento inteiramente casualizado em esquema fatorial 2X2, sendo os fatores processo de adaptação ao calor (controle e condicionamento térmico) e programa de luz (contínuo e intermitente). Aves condicionadas ao calor ou expostas à luminosidade intermitente ingeriram maior quantidade de água durante todo período de desafio térmico; no entanto, somente o programa de fornecimento intermitente de luz foi eficiente em reduzir a mortalidade final das aves. De fato, frangos submetidos à luminosidade intermitente apresentaram menor relação heterófilo: linfócito ao final do período de criação e ainda concentração plasmática de T4 e temperatura interna menores no início do período de estresse térmico. Frangos condicionados ao calor não apresentaram alteração na composição química da carcaça; porém, a deposição protéica das aves submetidas ao programa de fornecimento intermitente de luminosidade foi reduzida. Tais resultados evidenciam aparente ineficácia do processo de condicionamento térmico precoce em reverter os efeitos deletérios da exposição crônica e cíclica ao calor na fase final de criação. Entretanto, a adoção de um programa de fornecimento intermitente de luminosidade mostrou-se benéfica à maximização da tolerância das aves ao calor.
In order to evaluate the real efficacy of early age thermal conditioning in field conditions and clarify the physiological responses related to greater heat tolerance, 600 male broiler chicks were distributed in a 2X2 factorial design, with the factors - heat adaptation (control and heat conditioning) and light schedule (continuous and intermittent). Heat-conditioned and intermittent-lightexposed broilers drank more water during the final week of experiment; however, only the intermittent light program reduced flock mortality level significantly. In fact, intermittent-light-exposed broilers showed lower T4 plasmatic concentration and body temperature at the beginning of the heat-stress period and reduced heterophil to linfocyte ratio at the end of thermal challenge. Their carcass protein deposition at 42 days was decreased too. These results allow concluding that early age thermal conditioning seems to be inefficient on reducing the impact of chronic and cyclical heat exposure at marketing age. However, intermittent light program improve broiler heat tolerance.

Exposure to ambient temperatures has been widely described as an important health hazard. The most studied effect of temperatures is an increase on mortality; however, there is less evidence on other health impacts. In response to climate change and associated extreme events, public health adaptation has become imperative. The Spanish Government implemented in 2004 a heat health prevention plan (HHPP). This thesis aimed to evaluate the effectiveness of the Spanish HHPP in terms of reductions in mortality and cause-specific hospitalizations, and to assess the effects of weather factors on gastroenteritis and on occupational injuries. Daily maximum and average temperature, and daily precipitation in each capital of province were used as exposure measures. Daily counts of deaths, hospitalizations for cardiovascular, cerebrovascular and respiratory diseases, hospitalizations for infectious gastroenteritis and occupational injuries registered in Spain were included as health outcomes. Our results suggested that the implementation of the HHPP has reduced extreme heat-related mortality and respiratory admissions. By contrast, an increment of moderate heat-related mortality was observed. We also found that the effects of cold temperatures on mortality and respiratory admissions experienced a decrease in the second period, although this was not observed for cardiovascular and cerebrovascular admissions. Cold and heat were also associated with higher risk of gastroenteritis admissions and occupational injuries. An important economic impact of working at non-optimum temperatures has been estimated in this thesis. We observed a protective effect of heavy precipitation on gastroenteritis admissions. This thesis showed some improvements on health outcomes after the implementation of the HHPP. Nonetheless, ambient temperatures still have an important role in increasing health hazards. Public health prevention measures should consider all range of temperatures as well as target specific actions for some vulnerable groups, such as workers or children.
L'exposició a temperatures ambient ha estat àmpliament descrita com un important perill per a la salut. L'efecte més estudiat de les temperatures és un augment de la mortalitat, no obstant, l’evidència sobre altres impactes en salut és més escassa. Com a resposta al canvi climàtic i als seus esdeveniments extrems associats, mesures d'adaptació en salut pública són indispensables. El Govern espanyol va implementar el 2004 un pla de prevenció dels efectes en salut de la calor (HHPP). L’objectiu d’aquesta tesi era avaluar l'efectivitat del HHPP en quant a reducció de la mortalitat i de determinades causes específiques d’hospitalitzacions, així com avaluar els efectes dels factors climatològics en les gastroenteritis i les lesions laborals. Com a mesures d’exposició es van utilitzar la temperatura màxima i mitjana diària i la precipitació diària a cada capital de la província. Es van incloure, com a indicadors de salut, el nombre diari de defuncions, hospitalitzacions per malalties cardiovasculars, cerebrovasculars i respiratòries, hospitalitzacions per gastroenteritis infeccioses i lesions laborals registrades a Espanya. Els nostres resultats van suggerir que la implementació del HHPP va reduir la mortalitat i també els ingressos hospitalaris per malalties respiratòries relacionats amb la calor extrema. Per contra, es va observar un increment de la mortalitat relacionada amb la calor moderada. També es va constatar que els efectes de les temperatures fredes sobre la mortalitat i ingressos respiratoris van experimentar una disminució en el segon període, mentre que aquesta reducció no es va observar en els ingressos cardiovasculars i cerebrovasculars. El fred i la calor també es van associar amb un major risc d'ingressos per gastroenteritis així com de les lesions laborals. En aquesta tesi es va estimar un important impacte econòmic de treballar amb temperatures no òptimes. Es va observar un efecte protector de les precipitacions intenses en els ingressos per gastroenteritis. A més, aquesta tesi va mostrar algunes millores en salut després de la implementació del HHPP. De totes maneres, actualment les temperatures ambient suposen un perill per la salut. És necessari, per tant, que les mesures de prevenció en salut pública cobreixin tot el rang de temperatures, així com que s’estableixin accions específiques per a determinats grups vulnerables de població, com ara els/les treballadors/es o els infants.

There were two aims of this thesis, the first included updating a heat acclimation state test (HAST), prescribed to determine changes in heat dissipation capacity and evaluate the effectiveness of heat acclimation (HA). The second aim refined and investigated the efficacy of novel and applied, shortand long-term HA protocols to optimise the acquisition of heat adaptations and alleviate the deleterious effect of heat stress and subsequent physiological strain during exercise. Study 1 explored the reliability of a HAST prescribed from fixed rates of metabolic heat production (Ḣprod) per unit of body mass. The updated test was found to be reliable for heat acclimation state criteria (e.g. sweat setpoint and sweat gain). Study 2 investigated the sensitivity of the refined HAST and prescribed long-term heat acclimation (HA) for construct validity purposes. Large physiological and perceptual heat adaptations were found following HA and the HAST was sufficiently sensitive to highlight meaningful changes in heat acclimation state. Study 3 investigated a novel short-term, twice-daily heat acclimation (TDHA) protocol, to evoke heat adaptations within 2-days. Partial heat adaptations transpired, which alleviated heat strain and improved exercise tolerance (e.g. 3-km time trial). Study 4 investigated a once-daily STHA protocol within ultra-endurance athletes preparing for the Marathon des Sables (a multi-stage, ~250 km ultra-marathon) across the Sahara Desert in hot, dry conditions. Partial heat adaptations transpired, without compromising the athletes’ immune function. Study 5 and 6 built upon Study 1-4 and addressed some of the limitations found during this thesis. Study 5 and 6 investigated the efficacy of a non-consecutive TDHA protocol, compared to traditional consecutive once-daily HA, and matched temperate exercise groups. It was reported both HA protocols significantly enhanced heat acclimation state, induced large physiological heat adaptations and improved exercise tolerance in hot but not temperate conditions. No adverse effects in inflammatory or stress biomarkers were observed across HA protocols. This thesis displays the benefits of updating exercise prescription methods to quantify physiological adaptations and responses following HA accurately. Similarly, this thesis reports the efficacy of new TDHA protocols, which may afford athletes and emergency personnel (e.g. firefighters and military) recovery days during HA interventions, minimising the risk of immune dysfunction and may provide the opportunity to continue their training quality.

Heat stress (HS), a stress response in homeotherms mainly due to elevated ambient temperature and failure of effective heat dissipation, causes a substantial negative economic impact to livestock industry worldwide. Reduced feed intake, a typical phenomenon observed during HS, was thought to be the primary driver for the milk production loss. However, accumulating evidence indicates that HS influences animal metabolism and endocrine profiles independent of reduced feed intake. Previous studies comparing heat-stressed lactating cows with control group pair-fed (PF) to the intake of HS group but housed in thermoneutral conditions, in order to eliminate the confounding factors result from differentiated feed intakes, showed that HS increased circulating insulin and decreased plasma non-esterified fatty acid (NEFA) in lactating cow, the opposite responses typical of PF cohorts. Therefore, the present studies were performed in order to elucidate the mechanism(s) underlying these counterintuitive changes. In response to a glucose tolerance test (GTT), both HS and PF decreased whole body glucose disposal rate, a sign of insulin resistance. Only PF decreased skeletal muscle insulin sensitivity in terms of reduced protein kinase B (PKB/AKT) phosphorylation, a downstream protein of insulin receptor (IR), while HS group maintained similar intact insulin responsiveness in the liver and skeletal muscle as thermoneutral conditions. There was a global reduction in gene expression of the enzymes related to lipid metabolism in adipose tissue of heat-stressed cows. Similarly, β-adrenergic signaling, a major stimulator of lipid mobilization, was suppressed in terms of NEFA release response during a chronic epinephrine challenge in HS group. After the challenge, phosphorylations of cAMP-response element binding protein (CREB) and hormone sensitive lipase, both located downstream of β-adrenergic receptor, were decreased in HS, but not in thermoneutral conditions, another indicator of impaired adrenergic signaling. In contrast, IR and AKT phosphorylation were increased in HS conditions indicating insulin signaling may be elevated during HS in adipose. Collectively, HS reduces lipid mobilization and appears to favor glucose utilization via alterations of lipid metabolism and hormones signaling pathways. These unique alterations in HS might shed some light on developing counter-HS approaches in the future.
Ph. D.

A thesis submitted in partial fulfillment of the requirements for the degree of Doctor in Information Management, specialization in Geographic Information Systems
Urban systems are not only major drivers of climate change, but also impact hotspots. The processes of global warming and urban population growth make our urban agglomerations vulnerable to chain reactions triggered by climate related hazards. Hence, the reliable and cost-effective assessment of future climate impact is of high importance. Two major approaches emerge from the literature: i) detailed spatially explicit assessments, and ii) more holistic approaches consistently assessing multiple cities. In this multidisciplinary thesis both approaches were addressed. Firstly, we discuss the underlying reasons and main challenges of the applicability of downscaling procedures of climate projections in the process of urban planning. While the climate community has invested significant effort to provide downscaling techniques yielding localised information on future climate extreme events, these methods are not widely exploited in the process of urban planning. The first part of this research attempts to help bridge the gap between the communities of urban planners and climatologists. First, we summarize the rationale for such cooperation, supporting the argument that the spatial scale represents an important linkage between urban and climate science in the process of designing an urban space. Secondly, we introduce the main families of downscaling techniques and their application on climate projections, also providing the references to profound studies in the field. Thirdly, special attention is given to previous works focused on the utilization of downscaled ensembles of climate simulations in urban agglomerations. Finally, we identify three major challenges of the wider utilization of climate projections and downscaling techniques, namely: (i) the scale mismatch between data needs and data availability, (ii) the terminology, and (iii) the IT bottleneck. The practical implications of these issues are discussed in the context of urban studies. The second part of this work is devoted to the assessment of impacts of extreme temperatures across the European capital cities. In warming Europe, we are witnessing a growth in urban population with aging trend, which will make the society more vulnerable to extreme heat waves. In the period 1950-2015 the occurrence of extreme heat waves increased across European capitals. As an example, Moscow was hit by the strongest heat wave of the present era, killing more than ten thousand people. Here we focus on larger metropolitan areas of European capitals. By using an ensemble of eight EURO-CORDEX models under the RCP8.5 scenario, we calculate a suite of temperature based climate indices. We introduce a ranking procedure based on ensemble predictions using the mean of metropolitan grid cells for each capital, and socio-economic variables as a proxy to quantify the future impact. Results show that all the investigated European metropolitan areas will be more vulnerable to extreme heat in the coming decades. Based on the impact ranking, the results reveal that in near, but mainly in distant future, the extreme heat events in European capitals will be not exclusive to traditionally exposed areas such as the Mediterranean and the Iberian Peninsula. Cold waves will represent some threat in mid of the century, but they are projected to completely vanish by the end of this century. The ranking of European capitals based on their vulnerability to the extreme heat could be of paramount importance to the decision makers in order to mitigate the heat related mortality. Such a simplistic but descriptive multi-risk urban indicator has two major uses. Firstly, it communicates the risk associated with climate change locally and in a simple way. By allowing to illustratively relate to situations of other capitals, it may help to engage not only scientists, but also the decision makers and general public, in efforts to combat climate change. Secondly, such an indicator can serve as a basis to decision making on European level, assisting with prioritizing the investments and other efforts in the adaptation strategy. Finally, this study transparently communicates the magnitude of future heat, and as such contributes to raise awareness about heat waves, since they are still often not perceived as a serious risk. Another contribution of this work to communication of consequences of changing climate is represented by the MetroHeat web tool, which provides an open data climate service for visualising and interacting with extreme temperature indices and heat wave indicators for European capitals. The target audience comprises climate impact researchers, intermediate organisations, societal-end users, and the general public.

This dissertation analyzes the everyday work experiences of hospice, a type of end-of-life care. The following chapters integrate micro-sociological perspectives with meso- and macro- level explanations of organizational behavior to account for workers' performances of emotional labor, care-related identities, constraints on their daily work, and ultimately hospice workers' strong commitment to their jobs and the hospice philosophy. Using a mixed methodological approach, I argue that hospice workers engage in emotional labor, but that instead of feeling dissonance or alienation, hospice workers develop a positive identity around their work. Their identities and work experiences are still constrained by institutional forces, however. Hospice workers' experiences highlight two tensions in the administration of caring labor: keeping commitment during times of organizational change and balancing the needs of the self with the needs of the care recipient. The main contributions of this work include new understandings of the relationships between identity, emotions, and work; a novel combination of theories that better explain care workers' behaviors and constraints on their action; and, a refined approach to thinking about emotional labor.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2006.
Includes bibliographical references (p. 84-89).
Artificial Gravity (AG) provided by short-radius centrifugation is a promising countermeasure against the harmful physiological effects of prolonged weightlessness. However, the vestibular stimulus associated with making head movements while rotating presents a challenge. During a head movement, the semicircular canals are excited by a cross-coupled angular acceleration, resulting in tumbling sensations, perceived body tilt, non-compensatory vertical nystagmus, and motion sickness. Past experiments in the Man Vehicle Lab have studied adaptation to yaw head movements while rotating at 23 RPM. To investigate adaptation to head movements at a higher rotation rate, 28 subjects participated in a 3-Day protocol in which centrifuge velocity was incremented from 14 RPM on Day 1, to 23 RPM on Day 2, to 30 RPM on Day 3. Key findings included: 1) 24 subjects completed the protocol with average motion sickness levels remaining below 5 (out of 20). Feasibility of head movements at 30 RPM was demonstrated, suggesting that adaptation to higher rotation rates may be possible.
(cont.) 2) A motion sickness model used in conjunction with a quantitative semi-circular canal sensory conflict model and an adaptation parameter was effective in making general predictions of motion sickness and adaptation over the 3 days. 3) Intensity and duration of tumbling sensations adapted significantly over the 3 days. 4) The VOR time constant decreased significantly over the 3 days and appeared to reach a limit of approximately 3.5 seconds, which is near the estimated cupular time constant.
by Paul Z. Elias.
S.M.

Les vagues de chaleur sont encore peu documentées au Sahel, malgré un impact très fort sur les populations. L'objectif de cette thèse est d'apporter de nouvelles connaissances et une meilleure compréhension des processus et mécanismes mis en jeu dans les vagues de chaleur au Sahel au printemps. L'étude se structure autour de trois axes : (i) la détection des vagues de chaleur, (ii) la documentation de leurs caractéristiques morphologiques, dynamiques et thermodynamiques ainsi que leurs tendances climatiques et (iii) la compréhension des processus et mécanismes en jeu lors de ces événements. Dans un premier temps, une nouvelle méthodologie d’identification des vagues de chaleur, définies ici comme une forte augmentation de la température à des échelles synoptiques à intra-saisonnières, a été développée. Cette définition permet de détecter des vagues de chaleur « météorologiques », associées au temps sensible et qui constituent un véritable enjeu pour la prévision. La détection repose sur trois étapes : (i) un filtrage sélectionne les échelles souhaitées, ici synoptiques à intra-saisonnières ; (ii) les valeurs extrêmes des anomalies de températures ainsi calculées sont conservées, grâce à un seuil limite fixe égal au quantile Q90 ; et (iii) une contrainte morphologique est finalement appliquée pour identifier les événements de grande échelle cohérents dans le temps et l’espace. Par ailleurs, les températures maximales (Tmax) et minimales (Tmin) sont considérées séparément car leurs fluctuations résultent de processus distincts. Cette méthodologie a été appliquée à plusieurs types de jeux de données : un produit basé sur des observations locales (BEST), trois réanalyses météorologiques (ERA-Interim, NCEP2 et MERRA) et des simulations climatiques (CMIP5). Les vagues de chaleur détectées sont ensuite documentées en termes de caractéristiques morphologiques et thermodynamiques, et leurs tendances climatiques sont analysées. L’occurrence de ces événements se concentre particulièrement en début de printemps, et la tendance à la hausse de leurs températures s’explique principalement par le réchauffement moyen au Sahel. Les biais moyens de température dans les simulations, atteignant plus de 5°C dans certaines simulations climatiques, expliquent la plus grande partie des erreurs sur les températures des vagues de chaleur. Les événements détectés dépendent aussi de la méthodologie utilisée, c’est pourquoi nos résultats sont comparés avec ceux obtenus à partir d’autres méthodologies communément utilisées dans la littérature. Les processus et mécanismes mis en jeu lors des vagues de chaleur sont ensuite étudiés. Au printemps, les sols sont secs et le flux de chaleur latente très faible. Les vagues de chaleur détectées sur les Tmax sont anormalement sèches, celles en Tmin anormalement humides. Une dépression est présente lors des deux types d’événements et centrée sur la zone impactée. Les vagues de chaleur diurnes sont associées à un vent de nord-ouest alors que les vagues de chaleur nocturnes correspondent à un vent de sud-ouest, qui favorise l’advection d’humidité par le flux de mousson. La vapeur d’eau joue un rôle majeur sur les vagues de chaleur nocturnes, amplifiant l’effet de serre de l’atmosphère. Une première analyse indique que les vagues de chaleur détectées en Tmax ne sont pas associées à des couches limites plus profondes. Ces résultats soulignent qu’au Sahel, les vagues de chaleur sont associées à des mécanismes différents de ceux observés dans d’autres régions du monde, comme en Europe, où les vagues de chaleur font souvent intervenir des conditions anticycloniques et un assèchement des sols. La méthodologie a été finalement adaptée à la prévision des vagues de chaleur en temps réel et implémentée sur le site Internet http://acasis.sedoo.fr/. Ce travail a permis de suivre et prévoir en temps réel les vagues de chaleur impactant l’Afrique de l’ouest pendant les printemps 2016-2017.

Cardiovascular disease, including heart failure, is the leading cause of death among male and female Middle Eastern Americans. In 2016, a medical center located in the northeastern region of the United States had an estimated 35% of heart failure patients readmitted within 30 days of discharge, 10% of these readmitted patients belonged to the local Middle Eastern community. The gap in nursing practice noted by nursing staff, patients, and their families was that the patient education materials on heart failure were not tailored to the cultural beliefs and customs of this high-risk population. The purpose of this project was to adapt the American Heart Association teaching tools on heart failure education to the Middle Eastern community to enhance compliance with treatment care plans, minimize days spent in the hospital, and decrease the readmission rates. The practice-focused question explored whether a team of experts could adapt heart failure education materials for the Middle Eastern community. An expert team met weekly to adapt the teaching materials to include information regarding effective communication techniques, adaptation to religious strictures, and modification of behavioral risks specific to Middle Eastern cultures. The information gathered was compiled and will be shared with the host medical facility. The positive social change resulting from this project might include improved culturally appropriate communication and support for the medical center's Middle Eastern population of heart failure patients, which may result in improved health outcomes.

Avec la montée en charge de l’informatisation des systèmes d’information hospitaliers, une quantité croissante de données est produite tout au long de la prise en charge des patients. L’utilisation secondaire de ces données constitue un enjeu essentiel pour la recherche ou l’évaluation en santé. Dans le cadre de cette thèse, nous discutons les verrous liés à la représentation et à la sémantique des données, qui limitent leur utilisation secondaire en cancérologie. Nous proposons des méthodes basées sur des ontologies pour l’intégration sémantique des données de diagnostics. En effet, ces données sont représentées par des terminologies hétérogènes. Nous étendons les modèles obtenus pour la représentation de la maladie tumorale, et les liens qui existent avec les diagnostics. Enfin, nous proposons une architecture combinant entrepôts de données, registres de métadonnées et web sémantique. L’architecture proposée permet l’intégration syntaxique et sémantique d’un grand nombre d’observations. Par ailleurs, l’intégration de données et de connaissances (sous la forme d’ontologies) a été utilisée pour construire un algorithme d’identification de la maladie tumorale en fonction des diagnostics présents dans les données de prise en charge. Cet algorithme basé sur les classes de l’ontologie est indépendant des données effectivement enregistrées. Ainsi, il fait abstraction du caractère hétérogène des données diagnostiques initialement disponibles. L’approche basée sur une ontologie pour l’identification de la maladie tumorale, permet une adaptation rapide des règles d’agrégation en fonction des besoins spécifiques d’identification. Ainsi, plusieurs versions du modèle d’identification peuvent être utilisées avec des granularités différentes
With the increasing adoption of Electronic Health Records (EHR), the amount of data produced at the patient bedside is rapidly increasing. Secondary use is there by an important field to investigate in order facilitate research and evaluation. In these work we discussed issues related to data representation and semantics within EHR that need to be address in order to facilitate secondary of structured data in oncology. We propose and evaluate ontology based methods for heterogeneous diagnosis terminologies integration in oncology. We then extend obtained model to enable tumoral disease representation and links with diagnosis as recorded in EHR. We then propose and implement a complete architecture combining a clinical data warehouse, a metadata registry and web semantic technologies and standards. This architecture enables syntactic and semantic integration of a broad range of hospital information System observation. Our approach links data with external knowledge (ontology), in order to provide a knowledge resource for an algorithm for tumoral disease identification based on diagnosis recorded within EHRs. As it based on the ontology classes, the identification algorithm is uses an integrated view of diagnosis (avoiding semantic heterogeneity). The proposed architecture leading to algorithm on the top of an ontology offers a flexible solution. Adapting the ontology, modifying for instance the granularity provide a way for adapting aggregation depending on specific needs

Thermochemical heat storage (TCS) is a thermal energy storage (TES) technology used to store thermal energy for later use. TCS can provide heating or cooling services from intermittently available thermal energy, often low grade waste heat. The system studied here stores and releases the energy in the form of chemical energy by utilizing reversible chemical reactions. TCS has potential to reduce greenhouse gas emissions, increase infrastructure system efficiency, lower society-wide energy system costs and by that contribute to sustainable development. This thesis is part of a joint TCS research project named Neutrons for Heat Storage (NHS), involving three research institutes. The project is funded by Nordforsk and KTH Royal Institute of Technology. KTH´s objective in the NHS project is to design, build and operate a bench-scale TCS system using strontium chloride (SrCl2) and ammonia (NH3) as a solid-gas reaction system for low-temperature heat storage (40-80 ℃). Here, absorption of NH3 into SrCl2⋅NH3 (monoammine) to form SrCl2⋅8NH3 (octaammine) is used for heat release, and desorption (of NH3 from SrCl2⋅8NH3 to form SrCl2⋅NH3) for heat storage. Prior to this thesis project, this TCS system, as well as its reactor+heat exchanger (R-HEX) units, were numerically designed at KTH, and the R-HEX units were manufactured. This system is now being built at the laboratory of Applied Thermodynamics and Refrigeration division at the Department of Energy Technology, KTH. The initial system is comprised of a shared storage tank, expansion valve, ammonia meter and an R-HEX (absorption path); and an R-HEX, ammonia meter, gas cooler, compressor, condenser, and the storage tank (desorption path), to accommodate absorption, desorption, and NH3 storage. This thesis was originally planned to include commissioning, operation and experimental data acquisition, and performance evaluation of this system. However, due to various delays and shortcomings discovered at the beginning of the project, its objectives were then redefined to review the system and its components and propose necessary design adaptations of the initially designed (and partially built) system. This thesis project was partly a joint project, where Harish Seetharaman performed various tasks in the overarching NHS project as part of his own thesis project, performed alongside the work described in this report. For various information and results, referring to Harish´s report therefore will be necessary. A literature review of the research into SrCl2-NH3 systems was conducted, with emphasis on performance evaluation, kinetics, and reaction paths. TES performance evaluation is discussed concerning the TCS key performance indicators, with the 2018 IEA's Annex 30 as a guideline and 2013 IRENA´s E17 technology brief as a comparative reference. Much progress and refinement has been made in the 5-year span between the publications of these documents, but some adaptations and interpretations still need to be made to the Annex 30 approach for a good approach to a TCS system of similar nature as the one studied in this report. Review of the latest research on the kinetics and reaction path of the SrCl2-NH3 reaction pair revealed that the 100-year-old single-line-and-path reaction expression is an oversimplification of the actual chemistry. The reaction path seems to be dependent on the kinetics of the reaction, and varies with heating rate, temperature, and pressure. Various literature was found and compared, which show that the reaction enthalpies and entropies are not settled science. This demonstrates the necessity for further research into the SrCl2-NH3 reaction pair before application-scale product design and commercialization can take place. A comprehensive equipment and system review was conducted, whereby multiple issues were found and addressed, that if gone unnoticed, would have caused difficult setbacks for the project.  Consequently, the previous purchased ammonia flow meters and ammonia compressor, were exchanged for new and better suiting equipment. The original ammonia flow meters were undersized due to miscalculations of converting flow units of NLPH (Normal Liters Per Hour) to the project units of g/s, while wrongly using the density of compressed ammonia to convert to g/s, instead of it at the defined normal conditions. Furthermore, these flow meters were of the wrong type, as they had no digital output for data acquisition. The original compressor was also severely undersized, only capable of evacuating 7-14% of the expected maximum desorption flow. This was due to a similar miscalculation during conversion of NLMP (Normal Liters Per Minute) to g/s, as well as an unrequested compressor stroke reduction. New solutions and additional equipment were then required to accommodate the operational limitations discovered in the final chosen equipment and system configuration. These include limiting the compressor inlet pressure to a maximum of 1.1 bar(a); avoiding risk of NH3 condensation at them inlets of the new mass flow meters and compressor; and maintaining the flow meter and compressor inlet temperatures below 40 °C. The pressure limitations required considerable design adaptations. Firstly, an ammonia by-pass is introduced to keep feeding ammonia into the compressor during low desorption flows. The inlet pressure limitation necessitated active pressure management in the form of pressure reduction valves, which were thus introduced. Secondly, the condensation regulation and temperature management required a new approach, as the cooling and condensation temperatures in the original design were too low, causing risks of far too low temperature and pressure in the desorption path, as well as counter-acting simultaneous heating and cooling between the condenser and the storage tank heating sleeve. As a solution, a shunt pump is proposed, where constant cooling water temperature provides condensation on a tight temperature range using an infinite cold wall approach. Along with reviewing the equipment and the system design, new procedures concerning investigating and confirming homogeneous heat transfer properties of the reactors are proposed. Furthermore, improvements are suggested concerning the commissioning of the experimental rig, that include equipment testing with N2-gas and stepwise changes in temperature in sequential cycles to gain a good understanding of the likely behaviors of the system before it is run at the extremes of the operating range. In conclusion, a new and improved process flow diagram, showing all these adaptations, additions, and changes from the original diagram is presented herein as the final key contribution to the overarching NHS-project. This is complemented with an instruction manual, to allow the next researchers a smooth continuation, in terms of the system build, and later commissioning and operation. Finally, some suitable next steps in the project are suggested. These include a conceptualization of descriptive functions for the performance and behavior of the specific system and reactors. These functions are proposed with temperature and pressure as independent variables, as these are two main variables influencing the kinetics of the reaction in the given system. As no experimental data exists yet, the form of the proposed functions is generic. Furthermore, a suggestion is made for a future adaptation for achieving the phase change from NH3(g) to NH3(l) (which is the storage form of ammonia in the system) by deep cooling at the desorption pressure, resulting in only a liquid pump being required to raise the pressure of the NH3(l) in the storage tank.
Termokemisk energilagring (TCS) är en teknik inom termisk energilagring (TES) som används för att lagra termisk energi för senare bruk. TCS kan tillhandahålla värme och kyla från periodvis tillgänglig termisk energi, ofta lågtemperatur spillvärme. Systemet lagrar energin som kemisk energi genom att använda reversibla kemiska reaktioner och massaseparation av reaktions-produkterna. TCS har potential att minska utsläppet av växthusgaser, öka effektiviteten av system i vår infrastruktur, minska energikostnader i samhället och därmed bidra till hållbar utveckling. Detta exjobbsprojekt är en del av ett gemensamt TCS-forskningsprojekt som heter Neutrons for Heat Storage (NHS), där tre forskningsinstitut deltar. Projektet är finansierat av Nordforsk och Kungliga Tekniska Högskolan. KTH:s mål med NHS-projektet är att projektera, bygga, samt driva ett TCSsystem i bänkskala med strontiumklorid (SrCl2) och ammoniak (NH3) som ett fast-gasreaktionssystem för lågtemperaturvärmelagring (40-80 ℃). Här används absorption av NH3 till SrCl2⋅NH3 (monoammin) för att bilda SrCl2⋅8NH3 (oktaammin) för värmeurladdning och desorption (av NH3 från SrCl2⋅NH3 till SrCl2⋅NH3) för värmelagring. Innan detta exjobbsprojekt började hade detta TCS-system, samt systemets reaktor+värmeväxlare (R-HEX) enheter varit numeriskt projekterad vid KTH, och R-HEX-enheterna hade redan tillverkats. Detta system byggs nu på laboratoriet för Avdelningen för tillämpad termodynamik och kylning vid Institutionen för Energiteknik, KTH. Det initiala systemet består av en gemensam lagringstank, expansionsventil, ammoniakmätare, och en R-HEX (systemets absorptionssida) och en R-HEX, ammoniakmätare, gaskylare, kompressor, en kondensor, och en gemensamma lagringstanken (desorptionssidan), for att rymma absorption, desorption (samtidigt) och NH3-lagring. Exjobbsprojektet var ursprungligen planerat att inkludera driftsättning, drift och experimentdatainsamling samt utvärdering av systemet. På grund av olika förseningar och brister som upptäcktes i projektet, omdefinierades projektets mål och består nu av att granska systemet och, samt att föreslå nödvändiga designanpassningar av det ursprungligen konstruerade systemet och dess komponenter. Projektet var delvis ett gemensamt arbete, där Harish Seetharaman utförde olika uppgifter i det övergripande NHS projektet som en del av sitt eget exjobbssprojekt. För olika uppgifter och resultat kommer det därför att vara nödvändigt att hänvisa till Harishs rapport. Litteraturstudié av forskningen kring SrCl2-NH3 system genomfördes, med betoning på prestandautvärdering, kinetik och reaktionsvägar. Prestandautvärdering av TES system diskuteras angående TCS-nyckelindikatorer, med 2018 års IEA:s Annex 30 som riktlinje och IRENA:s E17 Teknologi-sammandrag från 2013 som en referens. Många framsteg och förbättringar har gjorts under femårsperioden mellan dessa publikationer, men vissa anpassningar och tolkningar måste fortfarande härledas till metoderna i Annex 30 för att få ett bra förhållningssätt till ett TCS-system av liknande karaktär som det som studeras i detta projekt. Granskning av den senaste forskningen avseende reaktionskinetik och reaktionsvägar för SrCl2-NH3 reaktionsparet visade att det hundraåriga enkellinje-och-reaktionsväg-formuleringen är en förenkling av den faktiska kemin. Reaktionsvägen verkar beroende av reaktionens kinetik och varierar med uppvärmnings-takten, temperaturen och även trycket. Olika litteratur jämfördes som visar att reaktionsentalpierna och entropierna inte är fastställd vetenskap. Detta visar behovet av ytterligare forskning avseende SrCl2-NH3 innan produktdesign och kommersialisering i applikations-skala kan utföras. En omfattande granskning av systemet och dess komponenter genomfördes, där flera problem hittades och åtgärdades. Om dessa problem hade gått obemärkt förbi skulle det ha orsakat svåra bakslag för projektet. Följaktligen byttes de tidigare köpta ammoniakflödesmätarna ut till nya och en ammoniakkompressor byttes ut mot en ny, för tillämpningen bättre anpassad. De ursprungliga ammoniak-flödesmätarna var underdimensionerade pga. felberäkningar i omvandling av flödesenheter för NLPH (normal liter per timme) till projektenheterna g/s. Samtidigt var densiteten av komprimerad ammoniak felaktigt använt för omvandling till g/s, istället för densiteten vid de definierade normala förhållandena; 1 bar (a) och 20 ° C. Dessutom var dessa flödesmätare av fel typ, eftersom de inte hade någon digital utgång för datainsamling. Den ursprungliga kompressorn var också kraftigt underdimensionerad, endast kapabel att evakuera 7-14% av det förväntade maximala desorptionsflödet. Detta berodde på en liknande felberäkning vid konvertering av NLPM (normal liter per minute) till g/s, samt en oönskad kompressorslagsminskning. Nya lösningar och ytterligare utrustning krävdes för att tillgodose de operativa begränsningar som upptäcktes i den slutgiltigt valda utrustningen och systemutformningen. Dessa inkluderar: begränsa kompressorns inloppstryck till maximalt 1,1 bar(a); undvika risk för NH3 kondens i de nya massflödesmätarna och kompressorn; samt bibehålla flödesmätarens och kompressorns inloppstemperaturer under 40 °C. Tryckbegränsningarna krävde omfattande projekteringsanpassningar. För det första införs en ammoniak-by-pass för att fortsätta mata ammoniak till kompressorn under låga desorptionsflöden. Inloppstrycksbegränsningen nödvändiggjorde aktiv tryckhantering i form av tryckreduceringsventiler. För det andra krävde kondensregleringen och temperaturhanteringen en ny strategi, eftersom kyl- och kondenseringstemperaturerna i den ursprungliga utformningen var för låga. Detta orsakade risker för alldeles för låg temperatur och tryck på desorptionssidan, samt samtidigt motverkande uppvärmning och kylning av kondensorn och förvaringstankens värmehylsa. Som en lösning föreslås en shunt där konstant kylvattentemperatur ger kondens i ett tätt temperaturintervall med en oändlig kallväggsinriktning. Tillsammans med granskning av utrustningen och systemutformningen föreslås nya tillvägagångssätt för undersökning och bekräftelse av reaktorers förmodade homogena värmeöverförings-egenskaper. Dessutom föreslås förbättringar av idrifttagningen av den experimentella riggen, som inkluderar utrustningstestning med N2-gas och stegvisa temperaturförändringar i sekventiella körningar för att få en god förståelse för systemets troliga beteenden innan det körs i ytterligheterna av systemts arbetsområde. Sammanfattningsvis presenteras ett nytt och förbättrat processflödesdiagram, som visar alla utförda anpassningar, tillägg och ändringar från det ursprungliga diagrammet, som är avhandlingsprojektets huvudbidrag till det övergripande NHS-projektet. Detta kompletteras med en bruksanvisning för att smidigt fasa in kommande forskare avseende systemets konstruktion, driftsättning, och drift. Slutligen föreslås några lämpliga kommande steg i projektet. Dessa inkluderar en konceptualisering av beskrivande funktioner för prestanda och beteende av det specifika systemet och reaktorer. Dessa funktioner föreslås med temperatur och tryck som oberoende variabler, eftersom dessa är två huvudvariabler som påverkar reaktionens kinetik. Eftersom inga experimentella data ännu finns, är formen för de föreslagna funktionerna generisk. Vidare ges förslag om framtida anpassning för att uppnå fasändringen från NH3(g) till NH3(v) (som är lagringsformen för NH3 i systemet) genom djup nedkylning vid desorptionstrycket, vilket resulterar i att endast en vätskepump krävs för att höja trycket för NH3(v) i lagringstanken.

Les projections climatiques prévoient une amplification du réchauffement climatique, potentiellement exacerbée en milieu urbain du fait du phénomène d’îlot de chaleur urbain. La recrudescence d’évènements extrêmes comme les canicules peut avoir des conséquences écologiques, sanitaires, et économiques dramatiques à l’échelle des villes qui concentrent la population. Parmi les mesures d’adaptation visant à améliorer le confort climatique et la demande énergétique, la climatisation et le verdissement urbain constituent deux leviers d’action aux effets parfois antagonistes. Ce travail de thèse – mené dans le cadre des trois projets de recherche CLIM2, MUSCADE et VegDUD, propose d’évaluer ces effets par des simulations du climat urbain à l’échelle de l’agglomération parisienne. La modélisation repose en particulier sur le modèle de canopée urbaine TEB qui permet de simuler les échanges de chaleur, d’eau et de quantité de mouvement entre les surfaces urbaines et l’atmosphère, et depuis peu l’énergétique des bâtiments et des indices de confort thermique dans les bâtiments et dans les rues. Afin d’améliorer la prise en compte de la végétation urbaine dans TEB, un modèle de toitures végétalisées extensives a tout d’abord été développé et évalué. Différentes pratiques d’arrosage de la végétation urbaine au sol ou sur les toits ont également été paramétrées. Les scénarios d’adaptation de la ville de Paris par la climatisation, évalués dans le cadre de CLIM2 pour la canicule 2003 par des simulations couplées de TEB avec un modèle atmosphérique, ont mis en évidence que toutes les formes de climatisation qui rejettent de la chaleur dans l’atmosphère (sèche ou humide) génèrent une augmentation de la température des rues au niveau des piétons. Ce réchauffement, proportionnel à la puissance des rejets de chaleur sensible dans l’atmosphère, est en moyenne de 0.5 à 2°C, selon le niveau de déploiement de la climatisation. Différentes stratégies de verdissement ont ensuite été mises en œuvre et évaluées toujours sur Paris, en faisant varier soit la végétation au sol (plusieurs taux et types de végétation testés), soit celle en toiture (avec ou sans arrosage), soit les deux. Ces simulations, réalisées dans la configuration générale du projet MUSCADE, i.e. en mode forcé avec une version de TEB disposant d’un générateur dynamique d’îlot de chaleur urbain, ont montré que l’augmentation de la couverture végétale au sol a un pouvoir rafraîchissant plus efficace que les toitures végétalisées, et ce d’autant plus que le taux de verdissement et que la proportion d’arbres sont importants. Les toitures végétalisées quant à elles constituent le moyen le plus efficace de réduire la consommation d’énergie, non seulement estivale mais aussi à l’échelle annuelle, essentiellement grâce à leur pouvoir isolant
Climate projections predict an amplification of global warming, potentially exacerbated in urban areas by the urban heat island effect. More frequent extreme events such as heat waves may have severe public health, ecological, and economic consequences as cities concentrate population. Among the measures aiming at improving thermal comfort or energy demand, air conditioning and urban greening are measures that may have antagonistic effects. This PhD work is undertaken within the framework of three research projects, CLIM2, MUSCADE and VegDUD. Its objective is to evaluate the respective effects of air conditioning and urban greening based on urban climate simulations across the Paris area. The modelling relies on the Town Energy Balance (TEB) model, which simulates the exchange of heat, water and momentum between the urban surface and the atmosphere. It has been recently improved to simulate building energetics, as well as indoor and outdoor thermal comfort indices. To improve the description of urban vegetation within TEB, a green roof model has been developed and evaluated. In addition, watering practices have been implemented to model the watering of urban vegetation at ground or roof level. Within CLIM2, the air conditioning scenarios tested for adapting Paris city to the extreme temperatures of the 2003 heatwave have been evaluated based on simulations using TEB coupled with an atmospheric model. Results shows that all forms of conditioning that release waste heat (dry or wet) into the atmosphere generate a temperature increase in the streets. This warming is proportional to the power of the sensible heat releases in the atmosphere and is on average 0.5 to 2_C, depending on the level of deployment of the air conditioning. Then, the greening of Paris city has been evaluated based on simulations carried out with the general configuration of the MUSCADE project, i.e. with climate forcings and a dynamic urban heat island generator. The scenarios tested consisted in an increase in ground-base vegetation or an implementation of green roofs on compatible buildings, or the two combined, with the option of watering green roofs or not in summer. Results show that increasing the ground cover has a stronger cooling effect than implementing green roofs, and even more so when the greening rate and the proportion of trees are important. The green roofs are however the most effective way to reduce energy consumption, not only in summer but also on an annual basis, mainly due to their insulating properties