Os hormônios tireoidianos (HT) executam um papel lipolítico importante no Tecido Adiposo Branco (TAB), sendo este efeito mediado por meio do aumento da expressão de receptores beta adrenérgicos na membrana do adipócito, o que aumenta a sensibilidade deste tecido as catecolaminas. Sabe-se que os principais efetores da ação lipolítica nesse tecido são a lipase hormônio sensível (LHS) e a lipase dos triglicerídeos dos adipócitos (ATGL), as quais hidrolisam os triglicerídeos em ácidos graxos e glicerol. Além disso, outros componentes estão envolvidos na atividade lipolítica, como as perilipinas, proteínas estas que envolvem a gota de gordura, formando uma barreira contra a ação da LHS e ATGL, de modo que precisam ser fosforiladas para que a LHS e ATGL possam exercer seu efeito lipolítico. Considerando: (a) a importância do tecido adiposo na homeostase energética e como fonte de citocinas, as quais estão relacionadas com a sensibilidade tecidual à insulina; (b) que a função e o metabolismo do tecido adiposo variam com a sua distribuição regional, e (c) que as ações lipolíticas dos HT, importantes reguladores da homeostase energética, têm sido muito pouco exploradas, pretendemos investigar, em ratos, (i) se os HT interferem na expressão da LHS, ATGL, perilipina A e dos receptores beta3 adrenérgicos no tecido adiposo branco, e (ii) se essas ações diferem nos distintos depósitos de gordura, o que poderia ampliar o campo de conhecimento sobre os efeitos lipolíticos destes hormônios e a nossa compreensão sobre a contribuição deles nas complicações associadas à obesidade e suas co-morbidades. / Thyroid hormones (TH) play an important lipolytic role in white adipose tissue (WAT). This effect is mediated by increased expression of beta-adrenergic receptors on adipocytes membrane, which increases the sensitivity of that tissue to catecholamines. It is known that the main effectors of the lipolytic action in WAT enzymatic activity, especially: hormone sensitive lipase (HSL) and adipose triglyceride lipase (ATGL), which hydrolyze triglycerides into fatty acids and glycerol. In addition, other components are involved in the lipolytic activity, such as perilipin. These proteins support the fat droplet, forming a protective barrier against HSL and ATGL action. Considering: (a) the importance of adipose tissue in energy homeostasis and as a source of cytokines which are related to insulin tissue sensitivity; (b) function and metabolism of adipose tissue vary with their regional distribution; and (c) lipolytic actions of HT, important regulators of energy homeostasis, have been little explored, we investigated in rats with hypothyroidism and submitted to T3 treatment: (i) TH effects on the expression of hormone sensitive lipase (HSL), adipose triglyceride lipase (ATGL),perilipin A and beta-3 adrenergic receptors in WAT, and (ii) if this action are different on subcutaneous and visceral fat depot. This study has increased our understanding about the contribution of these hormones on WAT metabolism and metabolic disease as obesity.

Os hormônios tireoidianos (HT) executam um papel lipolítico importante no Tecido Adiposo Branco (TAB), sendo este efeito mediado por meio do aumento da expressão de receptores beta adrenérgicos na membrana do adipócito, o que aumenta a sensibilidade deste tecido as catecolaminas. Sabe-se que os principais efetores da ação lipolítica nesse tecido são a lipase hormônio sensível (LHS) e a lipase dos triglicerídeos dos adipócitos (ATGL), as quais hidrolisam os triglicerídeos em ácidos graxos e glicerol. Além disso, outros componentes estão envolvidos na atividade lipolítica, como as perilipinas, proteínas estas que envolvem a gota de gordura, formando uma barreira contra a ação da LHS e ATGL, de modo que precisam ser fosforiladas para que a LHS e ATGL possam exercer seu efeito lipolítico. Considerando: (a) a importância do tecido adiposo na homeostase energética e como fonte de citocinas, as quais estão relacionadas com a sensibilidade tecidual à insulina; (b) que a função e o metabolismo do tecido adiposo variam com a sua distribuição regional, e (c) que as ações lipolíticas dos HT, importantes reguladores da homeostase energética, têm sido muito pouco exploradas, pretendemos investigar, em ratos, (i) se os HT interferem na expressão da LHS, ATGL, perilipina A e dos receptores beta3 adrenérgicos no tecido adiposo branco, e (ii) se essas ações diferem nos distintos depósitos de gordura, o que poderia ampliar o campo de conhecimento sobre os efeitos lipolíticos destes hormônios e a nossa compreensão sobre a contribuição deles nas complicações associadas à obesidade e suas co-morbidades. / Thyroid hormones (TH) play an important lipolytic role in white adipose tissue (WAT). This effect is mediated by increased expression of beta-adrenergic receptors on adipocytes membrane, which increases the sensitivity of that tissue to catecholamines. It is known that the main effectors of the lipolytic action in WAT enzymatic activity, especially: hormone sensitive lipase (HSL) and adipose triglyceride lipase (ATGL), which hydrolyze triglycerides into fatty acids and glycerol. In addition, other components are involved in the lipolytic activity, such as perilipin. These proteins support the fat droplet, forming a protective barrier against HSL and ATGL action. Considering: (a) the importance of adipose tissue in energy homeostasis and as a source of cytokines which are related to insulin tissue sensitivity; (b) function and metabolism of adipose tissue vary with their regional distribution; and (c) lipolytic actions of HT, important regulators of energy homeostasis, have been little explored, we investigated in rats with hypothyroidism and submitted to T3 treatment: (i) TH effects on the expression of hormone sensitive lipase (HSL), adipose triglyceride lipase (ATGL),perilipin A and beta-3 adrenergic receptors in WAT, and (ii) if this action are different on subcutaneous and visceral fat depot. This study has increased our understanding about the contribution of these hormones on WAT metabolism and metabolic disease as obesity.

No description available.

<p dir="ltr">Ice thermal energy storage (ITES) systems have long been an economic way to slash cooling costs in the commercial sector since the 1980s. An ITES system generates cooling in the formation of ice within a storage tank. This occurs during periods of the day when the cost of electricity is low, normally at night. This ice is then melted to absorb the energy within the conditioned space. While ITES systems have been prosperous in the commercial sector, they have yet to take root in the residential sector.</p><p dir="ltr">The U.S. Department of Energy (DoE) has published guidelines for TES. The DoE guidelines include providing a minimum of four hours of cooling, shifting 30-50% of a space’s cooling load to non-peak hours, minimizing the weight, volume, complexity, and cost of the system, creating a system than operates for over 10,000 cycles, enacting predictive control measures, and being modular to increase scale for larger single-family and multi-family homes [1]. The purpose of this research is to develop a model that meets these guidelines.</p><p dir="ltr">After extensive research in both experimental data, technical specifications, existing models, and best practices taken from the works of others a MATLAB model was generated. The modeled ITES system is comprised of a 1m diameter tank by 1m tall. Ice was selected as the PCM. A baseline model was constructed with parameters deemed to be ideal. This model generated an ITES system that can be charged in under four hours and is capable of providing a total of 22.18 kWh of cooling for a single-family home over a four-hour time period. This model was then validated with experimental data and found to have a root mean squared error of 0.0959 for the system state of charge. During the validation both the experimental and model estimation for the water/ice within the tank converged at the HTF supply temperature of -5.2°C.</p><p dir="ltr">With the model established, a parametric analysis was conducted to learn how adjusting a few of the system parameters impact it. The first parameter, reducing the pipe radius, has the potential to lead to a 152.6-minute reduction in charge time. The second parameter, varying the heat transfer fluid (HTF) within the prescribed zone of 0.7 kg/s to 1.2 kg/s, experienced a 4.8-minute increase in charge time for the former and a decrease in charge time by 5.4 minutes for the latter. The third parameter, increasing the pipe spacing and consequently increasing the ratio of mass of water to mass of HTF, yielded a negative impact. A 7.1mm increase in pipe spacing produced a 16.6-minute increase in charge time. Meanwhile, a 14.2mm increase in pipe spacing created a 93.3-minute increase in charge time and exceeded the charging time limit of five hours.</p><p dir="ltr">This functioning model establishes the foundation of creating a residential-scale ITES system. The adjustability and scalability of the code enable it to be modified to user specifications. Thus, allowing for various prototypes to be generated based on it. The model also lays the groundwork to synthesize a code containing an ITES system and a heat pump operating as one. This will aid in the understanding of residential-scale ITES systems and their energy effects.</p>

L’existence de concurrence dans l’industrie aérospatiale obligé à une évolution continue des technologies en lien avec une diminution des coûts de lancement et une fiabilité accrue. Ceci passe, entre autre, par l’amélioration des moyens de protection des charges utiles. Le but de cette thèse est de vérifier l’applicabilité des systèmes hétérogènes lyophobes (association d’un matériau nanoporeux et d’un liquide non-mouillant) dans l’amortissement des vibrations pour le confort de celles-ci. L’intrusion de liquide dans des SHL demande une énergie mécanique importante sous forme de pression. En fonction des propriétés du couple solide/liquide cette énergie peut être partiellement dissipée. Cette dissipation, de l’ordre de quelques dizaines de joules par gramme de matériau est bien supérieure à celle des systèmes conventionnels (élastomères, amortisseurs visqueux…) et montre une grande stabilité vis-à-vis de la fréquence, d’où leur intérêt dans l’amortissement des vibrations. Bien que l’eau soit déjà très largement étudié dans le cadre de la recherche sur les SHL, elle ne peut être utilisée que pour des températures comprises entre 0 et 100°C (à pression atmosphérique). Dans le but d’élargir cette gamme de températures jusqu’à -50°C, des mélanges ont été utilisés. L’ajout d’électrolytes dans l’eau permet de baisser la température de solidification du liquide. L’étude des solutions d’électrolytes a permis de mettre en évidence deux phénomènes différents menant à des augmentations de pressions d’intrusion et d’extrusion dans les SHL. Dans les matériaux microporeux (comme les ZIF-8 étudiés dans ce travail), un phénomène d’exclusion totale des ions de la matrice poreuse peut être observé. Cet effet est accompagné de l’apparition d’un terme de pression osmotique menant aux augmentations importantes de pressions d’intrusion et d’extrusion mises en évidence. Dans le cas où les ions peuvent pénétrer les pores, les variations de pressions d’intrusion et d’extrusion sont beaucoup plus faibles et ont été attribuées à des changements dans les propriétés de surface du liquide. Les matériaux mésoporeux (comme les MCM-41 étudiés au cours de ce travail) semblent se comporter de cette manière quels que soient les ions considérés. L’extension de la gamme d’application des SHL vers les hautes températures a été faite grâce à l’utilisation du Galinstan, alliage de gallium, d’indium et d’étain, non-toxique et liquide entre -20 et 1300°C environ. Ce liquide, associé à des verres mésoporeux rendus chimiquement inertes, a permis l’obtention de cycles de dissipation d’énergie reproductibles. Enfin, une étude numérique d’un amortisseur SHL simplifié dans un système mécanique a été menée. La variété des comportements a mis en évidence la complexité de ces systèmes qui nécessitent un dimensionnement très précis. Si cette condition est vérifiée, les amortisseurs SHL s’avèrent très efficaces et adaptables du fait de la grande variété des couples solide/liquide utilisables. / Competition in aerospace industry forces to follow a constant evolution of technologies linked to launching costs decreasing and reliability increasing. An improvement of payload protection systems is a way to achieve these conditions. The main issue of this PhD thesis is to verify the applicability of lyophobic heterogeneous systems (association of a nanoporous material and a non- wetting liquid) in vibrations damping for payload comfort. Intrusion of liquid in LH S requires a high mechanical energy in the form of p res sure. Depending on solid/liquid couple properties this energy can be partly dissipated. This dissipation, of the order of ten joules per gram of material, is far higher than classical systems (elastomeric ones, viscous dampers...) and shows a relative stability regarding to frequency variations. These properties explain their interest in vibrations damping applications. Although water is a very common liquid which is very studied in the research field of LHS, it can only be used in the 0 to 100˚C temperatures range (under atmospheric pressure). In order to broaden this temperatures range to -50˚C, electrolytes have been used. Adding electrolytes to water permits to decrease the liquid melting temperature. The study of electrolyte solutions has highlighted two different phenomena leading to intrusion and extrusion pressures increasing in LHS. In microporous materials (such as ZIF-8 studied here), a total exclusion phenomenon of ions from porous matrix can be observed. This effect leads to the appearance of an osmotic pressure term which explains high increasing of both intrusion and extrusion pressures. If ions can penetrate pores, intrusion and extrusion pressures increasing are smaller and have been explained by liquid surface properties changes. Mesoporous materials (such as MCM-41 studied here) seem to show this last behaviour whatever ion is. Increasing of LHS application range to high temperatures has been made using Galinstan, gallium, indium and tin alloy, which is non-toxic and stays liquid between approximately -20 and 1300˚C. This liquid, associated with chemically inert mesoporous glasses, permits to obtain reproducible energy dissipation cycles. Finally, a numerical study of a simplified LHS damper in a mechanical system has been done. The behaviours variety has brought to light the complexity of such a system which needs a very accurate design. If this condition is verified, LHS dampers can be very effective and adaptable thanks to the numerous solid/liquid couples which can be used.

The thesis presents methods and criteria for creation and optimization of design of computer experiments. Using the core of a program Freet the optimized designs were created by combination of these methods and criteria. Then, the suitability of the designs for statistical analysis of the tasks vith input random variables was assessed by comparison of the obtained results of six selected functions and the exact (analytically obtained) solutions. Basic theory, definitions of the evaluated functions, description of the setting of optimization and the discussion of the obtained results, including recommendations related to identified weaknesses of certain designs, are presented. The thesis also contains a description of an application that was created to display the results.

This thesis presents the reader the importance of optimization and probabilistic assessment of structures for civil engineering problems. Chapter 2 further investigates the combination between previously proposed optimization techniques and probabilistic assessment in the form of optimization constraints. Academic software has been developed for the purposes of demonstrating the effectiveness of the suggested methods and their statistical testing. 3th chapter summarizes the results of testing previously described optimization method (called Aimed Multilevel Sampling), including a comparison with other optimization techniques. In the final part of the thesis, described procedures have been demonstrated on the selected optimization and reliability problems. The methods described in text represents engineering approach to optimization problems and aims to introduce a simple and transparent optimization algorithm, which could serve to the practical engineering purposes.