Ce manuscrit de thèse s'intéresse à la modélisation et au contrôle des réfrigérateurs cryogéniques. Le cas particulier des réfrigérateurs soumis à de fortes variations de charges thermiques est étudié. Un modèle de chaque objet pouvant se trouver dans un réfrigérateur est proposé. La méthodologie d'assemblage pour obtenir le modèle des sous-systèmes qui composent le réfrigérateur est présenté, accompagnée de la méthode permettant d'obtenir une approximation linéaire des modèles des sous-systèmes. Grâce aux modèles développées, des lois de commande avancées sont synthétisées. Un contrôleur linéaire quadratique pour les stations de compression à deux ou trois niveaux de pression est proposé, ainsi qu'un contrôleur prédictif sous contrainte pour la boite froide. La particularité de ces stratégies de contrôle est qu'elles sont compatibles avec un automate programmable industriel (API) , doté d'une capacité de calcul et de stockage de donnée réduite. La capacité de prédiction en boucle ouverte du modèle développé est validé au regard de données expérimentales et les stratégies de contrôle sont validés en simulation et expérimentalement sur la station d'essais 400W@1.8K du SBT et sur la station de compression du LHC, au CERN. / This manuscript is concern with both the modeling and the derivation of control schemes for large cryogenic refrigerators. The particular case of those which are submitted to highly variable pulsed heat load is studied. A model of each objet that normally compose a large cryorefrigerator is proposed. The methodology to gather objects model into the model of a subsystem is presented. The manuscript also shows how to obtain a linear equivalent model of the subsystem. Based on the derived models, advances control scheme are proposed. Precisely, a linear quadratic controller for warm compression station working with both two and three pressures state is derived, and a predictive constrained one for the cold-box is obtained. The particularity of those control schemes is that they fit the computing and data storage capabilities of Programmable Logic Controllers (PLC) with are well used in industry. The open loop model prediction capability is assessed using experimental data. Developed control schemes are validated in simulation and experimentally on the 400W@1.8K SBT's cryogenic test facility and on the CERN's LHC warm compression station.

A atmosfera é um complexo sistema termodinâmico na qual a geração, conversão e dissipação de energia desempenham um papel fundamental no desenvolvimento e manutenção dos diversos sistemas de movimento de escala sinótica e na circulação geral. Neste trabalho, o ciclo de energia de Lorenz em área limitada foi aplicado para três casos de ciclogêneses, onde cada um desses se formou em uma das três principais regiões ciclogenéticas da costa leste da América do Sul. Além disso, foram analisadas as condições sinóticas, bem como a evolução da estrutura tridimensional de cada sistema desde o período prévio à formação até o seu decaimento. As análises mostraram que o ciclone que se formou na costa sul/sudeste do Brasil originou-se a partir de uma baixa desprendida nos níveis médios em uma região de fraca baroclinia. As conversões de energia mostraram que o sistema extraía energia cinética do escoamento zonal médio indicando, assim, que a instabilidade barotrópica foi dominante na sua formação. O sistema que se desenvolveu região da foz do Rio da Prata apresentou características de uma ciclogenêse do tipo bomba, com rápida intensificação. Além disso, devido à esse rápido crescimento foi observado a seclusão das frentes quente e fria. O ciclo de energia mostrou uma natureza baroclínica com forte contribuição de geração de energia potencial disponível pela liberação de calor latente da convecção. Já o sistema da região da costa sul da Argentina apresentou um desenvolvimento baroclínico clássico (com conversão de energia potencial disponível para energia cinética da perturbação) de uma ciclogenêse extratropical, desde a amplificação da onda até oclusão final das frentes associadas. Com base nessas análises observa-se que as ciclogêneses que se formam na América do Sul podem apresentar características variadas, tanto de desenvolvimento como de estrutura, que não são muitas vezes relacionadas à ciclogenêse clássica. / The atmosphere is a complex thermodynamic system in which energy generation, conversion and dissipation play a key role in the development and maintenance of the synoptic scale movement systems. In this paper, the Lorenz energy cycle in a limited area was applied for three cases of cyclogenesis, where each one of them formed in an important cyclogenetic region in the east of South America. Furthermore, the synoptic conditions were analyzed, as well as the evolution of the tridimensional structure, from its early formation until its decay. The analysis showed that the cyclone, which formed on Brazil south/southeastern coast, originated through a cut off low in the mid levels on a weak baroclinic region. The energy conversions indicated the system extracted kinetic energy from the basic flow, showing that the barotropic instability was dominant in its development. The system that occurred in the Rio da Prata mouth had features of a bomb-type cyclogenesis with fast intensification. Moreover, due to this event, the fronts seclusion were observed. The baroclinic nature with a strong contribution from the available potential energy generation term, through the latent heat release of the convection, can be observed by the conversion terms. Meanwhile, the system of the Argentina south coast presented a classical baroclinic development (which has the conversion from eddy available potential energy to eddy kinetic energy) of an extratropical cyclogenesis, from the wave amplification until the final occlusion of the associated frontal system. Based in this analysis, it is worthy to note that both the development and structure of the cyclogenesis that occur in the South American eastern coast can present varied features, which are often not related to classical cyclogenesis.

Abstract Winter energy management in small passerines living year-round in boreal or alpine areas presumably results in strong selective pressure since they need to find food, at a time when natural resources diminish and become less available, and energy requirements increase dramatically. In this thesis energy management during the non-breeding season was studied in three species of tits (Parus spp.), from three different populations: Coll de Pal (Spanish Pyrenees), Lund (Southern Sweden) and Oulu (Northern Finland). Energy management strategies vary significantly between species and among populations and individuals of the same species. Such differences may depend on several environmental factors, food predictability and individual characteristics. Birds from the studied populations appear to react to energetic challenges on a short-term basis and in a highly flexible way. The coal tit (Parus ater) in Coll de Pal and the willow tit (Parus montanus) in Oulu, both hoarding species, relied mostly on short-term management of energy for winter survival. Social and residence status appeared to be the most important factors in determining the level of energy reserves, underlining the importance of food predictability for energy management in wintering tits. Further studies were carried out on two distinct populations of great tit (Parus major) exposed to different winter hardiness. Birds from both populations increased their resting metabolic rate (MR) with experimentally decreasing ambient temperatures. Birds from Oulu maintained higher expenditures than birds from Lund in all cases, but also experienced higher energetic cost of thermoregulation at the lowest temperatures. The differences probably did not arise from a differential insulation capacity between populations, despite the differences in plumage structure found, but from a differential metabolic acclimatization. Birds from Lund probably became hypothermic at the lowest temperatures, which may have exceeded the levels they were acclimatized for. The observed differences in basal MR in laboratory conditions were consistent in wild birds throughout the non-breeding season. Birds from both populations experienced similar patterns of variation in basal MR, with expenditures increasing with mass but decreasing with day length, size and age. Great tits modulate their energy expenditure in a flexible way as a means for surviving the non-breeding season. Further, despite such flexibility, populations appear to be locally adapted for such metabolic acclimatization. These results may have important implications on their life-history and distribution. Winter acclimatization appears to be a complex set of entangled strategies that are based on a metabolic adjustment to cope with changing energy requirements. Other mechanisms that apparently play a secondary role, for example the long term management of reserves through fattening or hoarding, or conserving heat through hypothermia and by developing a better insulative plumage, are certainly important emergency strategies that in natural conditions may explain how some populations can endure winter conditions.

One of the most striking things about many animals is that they can be defined by the ways in which they move. Moving costs metabolic energy and is a significant contributor to the daily energy balance of organisms and therefore fitness. Balancing energy needs is critically important to species inhabiting areas of limited resources. The metabolic cost of locomotion is influenced by physiological, morphological and behavioural factors that vary across species. The influence of these factors within species is less well understood. The objective of my PhD is to elucidate the potential for variation in locomotor performance, in particular the energy consumed and the biomechanics of locomotion within a species, in response to differences in season, sex, age and the nature of the terrain. The Svalbard ptarmigan (Lagopus muta hyperborea) is the only year-round avian resident of the Arctic archipelago of Svalbard. Svalbard is characterized by extreme photoperiodic and climatic conditions, with 24 hours of daylight in summer and continuous darkness in winter, when ice makes food unpredictable. As a result, ptarmigan annually gain significant fat stores, as much as doubling their body mass in winter. The consequences of such large gains in mass upon the metabolic cost and biomechanics of terrestrial locomotion are yet to be quantified. The Svalbard ptarmigan represents a unique opportunity to gain insight into avian adaptations.Using respirometry, I present evidence that winter birds are able to carry their fat stores at no metabolic cost. Using kinematic and force plate data, I show that acquiring fat results in reduced locomotor performance in terms of speed and take-off ability. As well as exhibiting phenotypic variation, male and female Svalbard ptarmigan are behaviourally very different. I present evidence that these behavioural differences are reflected in the metabolic cost of locomotion. In particular, males are both more efficient and faster than female birds during both summer and winter. I suggest that this results from sexual selection upon male locomotor performance. Furthermore, I present data demonstrating that sub-adult males experiencing their first winter possess the same metabolic and speed capabilities of adults. These data may indicate that selection for improved male locomotor performance may act upon sub-adult birds. Regardless of season, age or sex, Svalbard ptarmigan must locomote on a predominantly sloping terrain. The influence of inclines upon the metabolic cost of locomotion in birds is poorly understood. I provide evidence that at the same degree of incline, the cost of lifting 1 kg by 1 vertical metre is similar regardless of season and is therefore dictated by increased positive work. However, this cost varies according to the degree of incline and may be influenced by gait.The principal findings of the 5 first author papers presented are that behavioural, physiological and morphological variation within a species can have significant impacts upon the metabolic cost of locomotion and other aspects of locomotor performance. The potential for intraspecific differences should therefore be taken into account in future research regarding the patterns of energy expenditure in animals.

The aim of this diploma thesis is to verify a connection between macroeconomic development and energy sector. This connection is examined with the data from the Czech Republic and with the data from Austria, both in the years 2000 - 2012. The theoretical part describes energetics as a natural monopoly and a resource of externalities. It includes the theory of monitoring the business cycle and financial analysis of companies. The first half of the practical part compares macroeconomic development of the Czech Republic and the ČEZ group. The similar comparison is made with Austria and the Verbund company. Second half of the practical part explains how economic policies influence the Czech energetics. This impact is being studied in terms of legislation, regulations, monetary and fiscal policy. The practical part ends with rating and valuation of costs that arise from the main energy resources. The link between energetics and macroeconomic development was discovered and proved thanks to the doubled analysis used in the thesis.

Strategic analysis of E.ON Czech group and its practical application, external and internal analysis and strategy.

Master's Thesis deals with issue of corporate social responsibility in the energy industry. The work is divided into four chapters. In the first one author describes basic concepts related to this issue, focusing on the current understanding of corporate social responsibility from a global and European perspective and of course from the perspective of the Czech Republic. Criticism, barries and the future of CSR are not missing as well. The second and the third chapter is dedicated to a detailed analysis of CSR in an example of global and regional company from the energy industry. Focus is on economic, social and environmental pillars of corporate social responsibility, together with the strategic objectives and innovation. Last fourth chapter compares the global and the regional energy company based on the tripple bottom line of the CSR and finally, strategy of the global and regional representative is confronted with a reality.

Identification of polysaccharides is not a straightforward task due to the high degree of stereochemistry present in their isobaric monomers. Their isobaric nature causes traditional mass spectrometry to fall short when trying to differentiate not only the conformation of the monomers but the position of the glycosidic bonds that bind them. This structural information is important for biochemists as they study the role of different glycans in biological processes. Tandem mass spectrometry (MS/MS) allows the study of the fragment ions formed during collision induced dissociation (CID), the fragments formed depend on the structure and stability of the precursor molecule and can be used to identify the compounds. These fragmentation pathways will be as complex as the species that form them. To date, typical saccharide fragments are separated into three groups that represent the major fragments: Cross-ring cleavages (A/X), and those resulting from cleaving different sides of the glycosidic bond (B/Y) and (C/Z). Ion mobility separation (IMS) has shown to have some success at discerning polysaccharide conformers and those of other biopolymers such as proteins and polynucleotides. Ion mobility separates gas-phase ions by colliding them with non-reactive gases and relating respective increase in flight time to their collision cross-section (CCS). In this study, the relative energetics of the first steps of the cross-ring cleavage and both glycosidic bond cleavage channels for isomaltotriose [glc(α1-6)glc(α1-6)glc] as well as a minor water loss channel were explored using density functional theory (DFT) calculations at the B3LYP/6-31+g(d) level of theory. It was demonstrated that charge-remote mechanisms are a viable alternative to charge-directed mechanisms when under the high energy short time scale conditions present during an ESI-MS/MS experiment. To verify the efficiency of ion mobility for isomeric separation, the relative experimental CCS of isomaltotriose [glc(α1-6)glc(α1-6)glc], maltotriose [glc(α1-4)glc(α1-4)glc], panose [glc(α1-6)glc(α1-4)glc] and raffinose [gal(α1-6)glc(α1-2)fru] were determined by comparison with literature CCS values for dextran, a variable-length oligomer of α1-6 linked glucose was used as an external calibrant. The experimental CCS of the precursor ions were compared to literature values when available as well as the calculated effective values of the optimized DFT geometries using the trajectory method of the MOBCAL computational suite. As phosphate is often used as an adducting agent to increase the intensity of the precursor ion when running an IMS experiment, the effect of its presence on the fragmentation of isomaltotriose and large isomaltooligosaccharides was studied. It was seen that depending on the location of the phosphate ion, it will preferentially dissociate leaving behind a neutral glycan. This explains the low abundance of fragment ions observed when selecting a phosphate-adducted precursor ion during an MS/MS experiment. IMS and MS-MS are complementary methods that can be used to identify monomers within a polysaccharide and how they are bound.

INTRODUCTION: Coupling in the distal foot may be due, at least in part, to the foot's windlass mechanism. This mechanism has been demonstrated passively, but its role in dynamic movement is still unclear. A systematic manipulation of metatarsophalangeal (MTP) mechanics may help determine to what extent distal foot coupling during dynamic and active movement is due to the windlass mechanism versus active muscle contractions or springlike ligaments. Furthermore, exploring the windlass mechanism in feet with varying foot structure may aid our understanding of the relationship between foot structure and foot function. PURPOSE: The overall purpose of this study is to investigate the kinematic and kinetic coupling between the MTP and midtarsal joints through a systematic manipulation of the windlass mechanism (achieved through methodical changes to MTP motion). Additionally, we aimed to explore the relationship between foot structure and the efficacy of the windlass mechanism during passive, active, and dynamic movement. METHODS: First, arch height and flexibility were measured using the Arch Height Index Measurement System. Next, participants performed four order-randomized conditions where MTP extension was isolated: 1) Seated Passive MTP Extension, 2) Seated Active MTP Extension, 3) Standing Passive MTP Extension, and 4) Standing Active MTP Extension. Lastly, participants performed three heel raise conditions that manipulated the starting position of the MTP joint: 1) Neutral: normal heel raise, 2) ToeExt: heel raise with the toes placed on an inclined surface of 30 degrees to put the MTP joint into extension, and 3) ToeFlex: heel raise with the toes placed on a declined surface of 30 degrees to put the MTP joint into flexion. All conditions were performed to a metronome of 40 beats per minute to control angular velocity. A kinetic multisegment foot model was created in Visual 3D software and used to calculate ankle, midtarsal, and MTP joint angles, moments, powers, and work. RESULTS: Kinematic coupling was approximately six times greater in the heel raise conditions compared to the isolated MTP extension conditions and suggests that the windlass mechanism only plays a small role in dynamic tasks. This is likely due to the greater involvement of active muscle contractions during heel raises. As the starting position of the MTP joint became increasingly extended, the amount of negative work at the MTP joint increased concomitantly with increased positive work done at the midtarsal joint, while net distal-to-hindfoot work remained unchanged. Our combined results suggest that there is substantial coupling within the distal foot, but this coupling is likely attributed to more than simple passive energy transfer from the windlass mechanism. Future investigations into the intrinsic foot muscle activation and biarticular muscle effects are likely needed to determine the source of this coupling. Lastly, the relationship between foot structure and function is still unclear and our results suggest that arch height or arch flexibility alone may not be adequate predictors of dynamic foot function.

Diet of cougars (Felis concolor) was studied from December 1978 to August 1981, on a 4500 km2 study area near Escalante, Utah. Prey eaten was determined from analysis of 112 animals consumed as prey, and from 239 cougar scats. Mule deer (Odocoileus hemionus) were the major prey item, comprising 81% of biomass consumed. Lagomorphs, large rodents, and smaller predators were also important components. Cattle comprised Motion-sensitive radio-transmitters were placed on 15 cougars, from 3 months to 7-9 years of age. Three parameters of the radio signal were used to determine activity levels during 6843 1-minute sampling periods: number of changes in pulse rate, predominant pulse mode, and signal integrity, based on 308 minutes of "known" acti vity. Cougars showed distinct crepuscular (sunrise, sunset ± 2 hrs) activity peaks (P Estimates of energetic costs of basal metabolism, and of activity, growth, and reproduction were used in a predictive model of energy cost of free-existence. Information on dietary composition, live weight and energy content of prey animals, and assimilation efficiencies were used to provide estimates of the frequency at which deer were killed (deer/day) and consumed (kg/day). Single adults were estimated to kill 1 deer per 8-16 days. Females with 3 large cubs would kill 1 deer as often as every 2-3 days. A known population of 8 adult cougars was predicted to consume 417 deer per year.