Nowadays, one of the solutions considered in order to face the issue of global warming and to move towards a carbon neutral society relies on the use of solar energy as a renewable and bountiful primary source. And, if photovoltaic technologies account for a large part in the solar energy market, recent years have witnessed the growth of non-concentrated and concentrated solar thermal technologies. Among them, concentrated solar power technology (CSP) which uses the optical concentration of direct solar irradiation to generate high pressure and high temperature steam in the absorber tubes of the plant, has become a promising approach reaching 4.9 GWe of installed capacity by the end of 2015 [1]. However, one of the main challenges faced by CSP technology concerns the variability of solar energy related for example to sunrise, sunset, passing clouds… In addition to that, when it comes to direct steam generation, the presence of a two-phase flow regime inside the absorber tubes leads to a strong dynamic behavior of the steam generation. It is consequently necessary to be able to simulate this dynamic behavior in order to better handle the design and operation of CSP plants. Such simulation tools can then be used for the implementation and the test of reliable control systems aimed at maintaining desired operating conditions in spite of changes in solar irradiation. In this context, the National Institute for Solar Energy (INES), part of the French Alternative Energies and Atomic Energy Commission (CEA) wishes to upgrade their dynamic simulation tool that would enable its teams to reproduce the behavior of a prototype based on the Fresnel solar field technology including direct steam generation which was built and commissioned at Cadarache, Aix-en-Provence. This Master thesis work takes place within this framework and aims at developing a multi-domain dynamic model of the aforementioned prototype. To do so, three models respectively in the thermalhydraulic, the optical and the control-command domains are built and combined using a co-simulation approach relying on an in-house simulation platform called PEGASE. More specifically the development of the following models has been addressed:  a thermal-hydraulic model of the two-phase flow circulating inside the vaporizer field of the prototype and realized with the thermal-hydraulic code CATHARE [2] (Advanced ThermalHydraulic Code for Water Reactor Accidents) applied to solar thermal biphasic issues,  an optical model of the receiver programmed using the Modelica language and the Dymola (Dynamic Modelling Laboratory) simulation software,  control-command models (PID controller, control architecture…) adapted and built upon blocks taken from a modelling library included in the PEGASE platform. Each model was first developed and tested on a standalone basis. These models were then coupled using the PEGASE co-simulation platform. A sunny day was simulated using the multi-domain model and the controllability of the plant was analyzed. At this stage, the study focused on the steam separator level regulation. A thermal-hydraulic study also focused on potential instabilities in the vaporizer that can occur under certain circumstances of water temperature at vaporizer inlet and solar heat flux. This analysis was carried out with a CATHARE standalone model. Perspectives of the present work include a complete validation of the developed models from future experimental data and further developments should aim to extend the modelling scope of the numerical simulator towards a representation of all the hydraulic parts of the CSP prototype. Control schemes and regulation tools would have to be extended as well in order to move towards a more representative control architecture of the prototype. Particularly, the steam quality at vaporizer outlet is an important variable to regulate. Indeed, this parameter is usually kept between 60% and 80% [3]. It must be high enough to limit the power consumption of the recirculation pump but not too high in order to prevent absorber dry-out. / Solenergi, som är en förnybar och riklig primärkälla, är en av de lösningarna som anses kunna lösa problemet med global uppvärmning och bidrar i omvandlingen till ett kolneutralt samhälle. Andelen fotovoltaiska teknologier på energimarknaden är övervägande, men andelen koncentrerad och ickekoncentrerad solterminsteknik har ökat under de senaste åren. Bland solterminsteknikerna är koncentrerad solenergiteknik (CSP), som använder den optiska koncentrationen av direkt strålning för att generera högtrycks- och högtemperaturånga i anläggningens absorberarrör, ett lovande tillvägagångssätt som har nått 4.9 GWe installerad kapacitet i slutet av 2015 [1]. En av de största utmaningarna med CSP-tekniken är solenergins variation vid till exempel soluppgång, solnedgång och passerande moln, vilket beror på varierad tillgång av solljus. Det finns också utmaningar med direkt ånggenerering via tvåfasflödes regimer inuti absorberarrören eftersom det leder till ett starkt dynamiskt beteende vid ånggenereringen. Det är följaktligen nödvändigt att kunna simulera detta dynamiska beteende för att bättre hantera design och drift av CSP-anläggningar. Sådana simuleringsverktyg kan sedan användas för att genomföra tester för att erhålla tillförlitliga styrsystem som upprätthåller önskade driftsförhållanden trots förändringar i solstrålningen I detta sammanhang vill National Institute for Solar Energy (INES), som är en del av den franska alternativa energikommissionen och atomenergi kommissionen (CEA), förbättra dess dynamiskt simuleringsverktyg som skulle möjliggöra för sina team att reproducera beteendet hos en prototyp baserad på Fresnel solfältsteknik inklusive direkt ånggenerering som byggts och beställts vid Cadarache, Aix-enProvence. Denna masteruppsats sker inom ramen för detta och syftar till att utveckla en dynamisk modell med flera domäner av den ovan nämnda prototypen. Tre modeller i termisk-hydraulisk, optisk och kontrollkommando domäner har byggts och kombinerats med hjälp av en co-simuleringsmetod som bygger på en intern simuleringsplattform som heter PEGASE. Mer specifikt om utvecklingen av modellerna enligt nedan:  En termisk-hydraulisk modell av tvåfasflöde som cirkulerar inuti förångarens fält på prototypen har realiserats med termisk-hydraulisk kod CATHARE [2] (Advanced Thermal-Hydraulic Code for Water Reactor Accidents) som appliceras på soltermisk bifasiska frågeställningar.  En optisk modell av mottagaren har programmerats med hjälp av Modelica-språket och simuleringsprogrammet Dymola (Dynamic Modeling Laboratory).  Modeller av kontrollkommandon (PID-kontroller, kontrollarkitektur ...) har byggts och anpassats i moduler som hämtats från modelleringsbibliotek som ingår i PEGASE-plattformen. Varje modell utvecklades och testades på fristående basis. Modellerna kopplades sedan samman i PEGASE-co-simuleringsplattformen. En solig dag simulerades därefter med en flerdomänmodell och styrningsförmågan av anläggningen analyserades. Vid detta stadium fokuserade studien på att reglera nivån av ångseparerande. En termisk-hydraulisk studie fokuserade sedan på potentiella instabiliteter i förångaren som kan uppstå under vissa omständigheter av vatteninloppstemperatur och solvärmeflöde. Denna analys genomfördes med en CATHARE fristående modell. Perspektiven för det aktuella arbetet omfattar en fullständig validering av de utvecklade modellerna med hjälp av framtida experimentella data. Vid en vidareutveckling bör inriktningen vara att utvidga modellernas omfattning av den numeriska simulatorn till att representera alla hydrauliska delar av CSP prototypen. Styrsystem och regleringsverktyg skulle också behöva förbättras för att få en mer representativ kontroll arkitektur av prototypen. I synnerhet är ångkvaliteten vid förångarens utlopp en viktig variabel att reglera. Faktum är att den här parametern vanligtvis hålls mellan 60% och 80% [3]. Det måste vara tillräckligt högt för att begränsa recirkulationspumpens elförbrukning men inte för hög för att förhindra att absorberen torkar ut.

Thesis (PhD) -- Stellenbosch University, 2014. / ENGLISH ABSTRACT: Currently the reduction of the levelised cost of electricity (LCOE) is the main goal of concentrating solar power (CSP) research. Central to a cost reduction strategy proposed by the American Department of Energy is the use of advanced power cycles like supercritical steam Rankine cycles to increase the efficiency of the CSP plant. A supercritical steam cycle requires source temperatures in excess of 620°C, which is above the maximum storage temperature of the current two-tank molten nitrate salt storage, which stores thermal energy at 565°C. Metallic phase change materials (PCM) can store thermal energy at higher temperatures, and do not have the drawbacks of salt based PCMs. A thermal energy storage (TES) concept is developed that uses both metallic PCMs and liquid metal heat transfer fluids (HTF). The concept was proposed in two iterations, one where steam is generated directly from the PCM – direct steam generation (DSG), and another where a separate liquid metal/water heat exchanger is used – indirect steam generation, (ISG). Eutectic aluminium-silicon alloy (AlSi12) was selected as the ideal metallic PCM for research, and eutectic sodium-potassium alloy (NaK) as the most suitable heat transfer fluid. Thermal energy storage in PCMs results in moving boundary heat transfer problems, which has design implications. The heat transfer analysis of the heat transfer surfaces is significantly simplified if quasi-steady state heat transfer analysis can be assumed, and this is true if the Stefan condition is met. To validate the simplifying assumptions and to prove the concept, a prototype heat storage unit was built. During testing, it was shown that the simplifying assumptions are valid, and that the prototype worked, validating the concept. Unfortunately unexpected corrosion issues limited the experimental work, but highlighted an important aspect of metallic PCM TES. Liquid aluminium based alloys are highly corrosive to most materials and this is a topic for future investigation. To demonstrate the practicality of the concept and to come to terms with the control strategy of both proposed concepts, a storage unit was designed for a 100 MW power plant with 15 hours of thermal storage. Only AlSi12 was used in the design, limiting the power cycle to a subcritical power block. This demonstrated some practicalities about the concept and shed some light on control issues regarding the DSG concept. A techno-economic evaluation of metallic PCM storage concluded that metallic PCMs can be used in conjunction with liquid metal heat transfer fluids to achieve high temperature storage and it should be economically viable if the corrosion issues of aluminium alloys can be resolved. The use of advanced power cycles, metallic PCM storage and liquid metal heat transfer is only merited if significant reduction in LCOE in the whole plant is achieved and only forms part of the solution. Cascading of multiple PCMs across a range of temperatures is required to minimize entropy generation. Two-tank molten salt storage can also be used in conjunction with cascaded metallic PCM storage to minimize cost, but this also needs further investigation. / AFRIKAANSE OPSOMMING: Tans is die minimering van die gemiddelde leeftydkoste van elektrisiteit (GLVE) die hoofdoel van gekonsentreerde son-energie navorsing. In die kosteverminderingsplan wat voorgestel is deur die Amerikaanse Departement van Energie, word die gebruik van gevorderde kragsiklusse aanbeveel. 'n Superkritiese stoom-siklus vereis bron temperature hoër as 620 °C, wat bo die 565 °C maksimum stoor temperatuur van die huidige twee-tenk gesmelte nitraatsout termiese energiestoor (TES) is. Metaal fase veranderingsmateriale (FVMe) kan termiese energie stoor by hoër temperature, en het nie die nadele van soutgebaseerde FVMe nie. ʼn TES konsep word ontwikkel wat gebruik maak van metaal FVM en vloeibare metaal warmteoordrag vloeistof. Die konsep is voorgestel in twee iterasies; een waar stoom direk gegenereer word uit die FVM (direkte stoomopwekking (DSO)), en 'n ander waar 'n afsonderlike vloeibare metaal/water warmteruiler gebruik word (indirekte stoomopwekking (ISO)). Eutektiese aluminium-silikon allooi (AlSi12) is gekies as die mees geskikte metaal FVM vir navorsingsdoeleindes, en eutektiese natrium – kalium allooi (NaK) as die mees geskikte warmteoordrag vloeistof. Termiese energie stoor in FVMe lei tot bewegende grens warmteoordrag berekeninge, wat ontwerps-implikasies het. Die warmteoordrag ontleding van die warmteruilers word aansienlik vereenvoudig indien kwasi-bestendige toestand warmteoordrag ontledings gebruik kan word en dit is geldig indien daar aan die Stefan toestand voldoen word. Om vereenvoudigende aannames te bevestig en om die konsep te bewys is 'n prototipe warmte stoor eenheid gebou. Gedurende toetse is daar bewys dat die vereenvoudigende aannames geldig is, dat die prototipe werk en dien as ʼn bevestiging van die konsep. Ongelukkig het onverwagte korrosie die eksperimentele werk kortgeknip, maar dit het klem op 'n belangrike aspek van metaal FVM TES geplaas. Vloeibare aluminium allooie is hoogs korrosief en dit is 'n onderwerp vir toekomstige navorsing. Om die praktiese uitvoerbaarheid van die konsep te demonstreer en om die beheerstrategie van beide voorgestelde konsepte te bevestig is 'n stoor-eenheid ontwerp vir 'n 100 MW kragstasie met 15 uur van 'n TES. Slegs AlSi12 is gebruik in die ontwerp, wat die kragsiklus beperk het tot 'n subkritiese stoomsiklus. Dit het praktiese aspekte van die konsep onderteken, en beheerkwessies rakende die DSO konsep in die kollig geplaas. In 'n tegno-ekonomiese analise van metaal FVM TES word die gevolgtrekking gemaak dat metaal FVMe gebruik kan word in samewerking met 'n vloeibare metaal warmteoordrag vloeistof om hoë temperatuur stoor moontlik te maak en dat dit ekonomies lewensvatbaar is indien die korrosie kwessies van aluminium allooi opgelos kan word. Die gebruik van gevorderde kragsiklusse, metaal FVM stoor en vloeibare metaal warmteoordrag word net geregverdig indien beduidende vermindering in GLVE van die hele kragsentrale bereik is, en dit vorm slegs 'n deel van die oplossing. ʼn Kaskade van verskeie FVMe oor 'n reeks van temperature word vereis om entropie generasie te minimeer. Twee-tenk gesmelte soutstoor kan ook gebruik word in samewerking met kaskade metaal FVM stoor om koste te verminder, maar dit moet ook verder ondersoek word.

Le paradigme de l’Internet Physique a été introduit il y a quelques années pour transformer globalement la manière dont les objets physiques seront manipulés, entreposés et transportés dans le cadre d’une logistique durable. L’une des caractéristiques importante de l’Internet Physique est liée à l’encapsulation des marchandises dans des conteneurs modulaires standardisés. Le modèle de fonctionnement proposé de l’Internet Physique, s’il rationnalise les transports, engendre des manutentions plus nombreuses, en particulier au sein des PI-hubs, où les opérations de routage, de déchargement et (re)chargement des conteneurs nécessitent une organisation et une gestion rationnelle. La multiplicité et la diversité des opérations (automatisées ou non) à mettre en œuvre simultanément ne peut être conduite de manière efficiente qu’en cas de parfaite synchronisation entre la réalité du système physique et de celle du système informationnel. Les propositions de cette thèse adressent cette problématique applicative et constituent à ce titre une contribution au concept de l’Internet Physique. Elles visent à l’obtention, en temps réel, d’une image ou d’un modèle spatial des PI-conteneurs, qui disposent chacun d’un nœud WSN. L’assemblage de ces différents conteneurs au sein d’un conteneur de plus haut niveau (ou conteneur composite) permet de constituer alors un réseau de capteurs ad-hoc. Ces conteneurs deviennent ainsi des éléments actifs de l’automatisation de la chaine logistique. A partir des seules informations de proximité issues de cette instrumentation, nous montrons dans cette thèse qu’il est possible de construire le modèle spatial des PI-conteneurs / The Physical Internet paradigm was introduced few years ago to transform globally how physical objects will be handled, stored and transported as part of a sustainable logistics. One of the important characteristics of the Physical Internet is the encapsulation of goods in standardized modular containers. Although the Physical Internet rationalizes transport, it generates more frequent handling, particularly within PI-hubs, where the operations of routing, unloading and (re) loading containers require an efficient organization and management. The multiplicity and the diversity of operations (automated or not) to be implemented simultaneously can only be carried out efficiently in the case of perfect synchronization between the reality of the physical system and that of the information system. The proposals of this thesis address this problem and constitute a contribution to the concept of the Physical Internet. They aim to obtain in real time, the spatial distribution (or layout) of the PI-containers when they are stacked in a higher-level container, so called composite container. To do this, we propose to exploit the intelligence and the activeness concepts of each PI container which is equipped with wireless sensor node. Hence, the composition of a composite PI containers constitutes an adhoc network of sensor nodes. From neighborhood relationships between these nodes, we show in this thesis that it is possible to construct the spatial 3D layout of the PI-containers and control at any time and at any place the effective compliance between the real composition and the data stored in the information system

This thesis challenges two key assumptions made in the current Islamic banking literature. Firstly, this thesis challenges and empirically invalidates the assumption that all Islamic banks are indistinguishable from their conventional counterparts and are thus equally unIslamic. To do so, this thesis uses the profit and loss sharing (PLS) criteria, which is central to the philosophy of Islamic banking and is the key principle differentiating Islamic from conventional banking, in theory and practice. By investigating variation in PLS levels between Islamic banks and comparing with conventional banks with and without Islamic windows, this thesis illustrates that the Islamic banking industry does not comprise a homogeneous group of banks that are all indistinguishable from their conventional counterparts. Rather, a typology of Islamic banks exists, comprising of three distinct groups of banks, each one following a different business model. While one group can genuinely be considered indistinguishable from conventional banks, another group shows clear evidence of pursuing PLS-oriented strategies in formulating its asset portfolio, differentiating itself from the purely debt-based intermediation model adopted by conventional banks. As such, empirical evidence shows that some Islamic banks are, in practice, operating closer to the PLS principle and can thus be considered more Islamic than others. Further investigation illustrates that the institutional environment matters for the provision of ideal PLS Islamic financing instruments. Secondly, this thesis overcomes two methodological issues to compare the corporate social performance (CSP) of Islamic and conventional banks. In doing so, this thesis challenges the second identified assumption from the literature, that religion-specific category of corporate social responsibility (CSR) is particular to Islamic banking, and invalidates it on conceptual, theoretical and empirical basis. A novel CSP Index based on the evidence-based disclosure criteria, comprising of 6 dimensions and 25 social performance indicators is constructed and complemented with three Social Performance Quantitative Indicators (SPQIs) to compare the CSP of Islamic and conventional banks. From this comparison, this thesis concludes that, contrary to the industry s claims and expectations held of it, Islamic banking does not offer an ethical alternative to conventional banking. Differences in the level and composition of CSP between the two industries are more subtle and require a nuanced approach to be studied.

Dans les disciplines de l'intelligence artificielle et de la recherche opérationnelle, on rencontre de nombreux problèmes comme l'allocation de ressources, l'ordonnancement, la, conception, le diagnostic automatisé. Ces problèmes se formulent aisément comme des problèmes de satisfaction de contraintes (CSP). Un CSP est défini comme étant un ensemble de contraintes impliquant un certain nombre de variables. L'objectif consiste simplement à trouver un ensemble de valeurs à affecter aux variables, de sorte que toutes les contraintes soient satisfaites. Dans le cas le plus général, les problèmes de satisfaction de contraintes ont un aspect fortement combinatoire qui leur confère une grande complexité. Nous nous intéressons dans le cadre de cette thèse aux problèmes de satisfaction de contraintes binaires en domaines finis. Les méthodes auxquelles nous nous intéressons pour résoudre un CSP sont, les méthodes dites incomplètes : elles font une réparation d'une configuration en parcourant de manière non systématique l'espace des configurations. Dans cette catégorie de méthodes, notre intérêt s'est plus particulièrement tourné vers les Algorithmes Evolutionnistes. Ce sont des méthodes générales d'optimisation combinatoire qui sont inspirées de la théorie de l'évolution. Dans un CSP classique, on recherche une solution, sans avoir à optimiser de fonction. Pour entrer dans le cadre des Algorithmes Évolutionnistes, on se doit de définir une fonction d'évaluation pour les CSP qui prend ses valeurs minimales sur les solutions du problème. Cette fonction pourrait être utilisée par toutes méthodes incomplètes, telles que les techniques min-conflits, GSAT et leurs variantes. Nous montrons dans cette thèse l'application de notre fonction d'évaluation pour la méthode min-conflits ainsi que pour un algorithme évolutionniste. D'un autre côté, dans le contexte plus spécifique des algorithmes génétiques, nous souhaitons guider l'évolution (i.e. recherche d'une solution), en faisant des transformations sur la population plus orientées vers le problème de satisfaction de contraintes. Nous définissons ainsi des opérateurs de mutation et de croisement spécialisés pour les CSP qui sont basés sur la structure du graphe de contraintes. Ensuite, nous incorporons le concept d'adaptation dans l'opérateur de croisement, afin d'améliorer la recherche de l'algorithme. Dans ce mémoire, nous décrivons et justifions les algorithmes mis en oeuvre, en illustrant les techniques implémentées par la résolution de problèmes de coloriage de graphe avec trois couleurs, et de CSP générés aléatoirement.

Un très grand nombre de problèmes combinatoires appartient à la famille des problèmes de satisfaction de contraintes (Constraint Satisfaction Problem ou CSP) : configuration, ordonnancement, affectation de ressources... Ces problèmes partagent une description commune qui autorise en général une modélisation claire et intuitive. Dans cette thèse, nous avons proposé et étudié une nouvelle méthode de résolution hybride pour les CSPs. Nous avons nommé cette méthode Tabu-NG pour Tabu Search based on NoGood. Le nom est un peu réducteur car il s'agit d'une hybridation d'algorithme de filtrage, de propagation de contraintes, de Recherche Tabou et de gestion de nogoods. La méthode a été appliquée sur deux types de problèmes. Le premier est l'affectation des fréquences (FAP) dans les réseaux de radiocommunications militaires, en particulier les problèmes proposés de 1993 (instances du projet européen CALMA) jusqu'à 2010 (instances d'un projet DGA). Le deuxième est le problème académique de k-coloration de graphes sur les instances DIMACS. La méthode a amélioré quelques meilleurs scores connus actuellement. Dans les deux problèmes nous avons traité des contraintes unaires et binaires, ainsi que des contraintes n-aires et de l'optimisation de fonction sous contraintes pour le FAP. Les principes de Tabu-NG sont généraux et elle peut s'appliquer sur d'autres CSP. Elle peut par ailleurs accueillir des heuristiques spécifiques aux problèmes, nous l'avons pratiqué sur les problèmes cités, et en ce sens nous pensons pouvoir qualifier la méthode de métaheuristique sans abuser de cette définition.

L'objectif de cette thèse est d'appliquer, aux problèmes de fusion de données, les techniques de résolution des CSP (Problèmes de Satisfaction de Contraintes) sur des pavés réels avec comme application réelle la localisation dynamique d'un véhicule à l'aide des capteurs odométriques, d'un gyromètre de lacet et d'un GPS différentiel.<br />Après avoir mené cette étude et tiré des conclusions, deux contributions sont faites pour améliorer les techniques de satisfaction de contraintes utilisées. Dans un premier temps, la notion de "domaine de consistance" est introduite. Les propriétés qui lui sont associées permettent de résoudre de manière formelle des exemples de cycles. Grâce à cet outil, on améliore la précision des pavés obtenus tout en ayant une information précieuse du temps de calcul a priori. Dans un second temps, l'algorithme de propagation connu sous le nom de FALL/CLIMB permettant de résoudre de façon optimale un CSP ayant une représentation graphique sous forme de graphe est généralisé aux CSP vectorisés appelés "VCSP".

企業社會績效(Corporate Social Performance; CSP)和企業財務績效(Corporate Financial Performance; CFP)的關聯性是近年來在學術界最常被討論的一個議題，從企業經營的觀點，到底企業進行企業社會責任(Corporate Social Responsibility; CSR)所表現出來的企業社會績效能不能帶動企業財務績效的提升最後創造企業價值(Firm Value; FV)，則是許多企業經營者所關心的。本文試圖研究企業社會績效和企業價值的關聯，希望藉由全盤的分析，從企業社會績效對企業財務績效的因果關係，和企業社會績效透過何種管道提升企業價值，以及企業到底該如何看待企業社會責任這幾個面向，去探討企業社會績效和企業價值的關係。希望能夠將學理上的理論和實務面的思考進行結合。 　　本研究利用Tobin’ q拆解的方式分析可能的假說，接著採取迴歸模型進行實證分析，之後進一步利用兩階段迴歸模型排除可能的內生性問題，最後得到以下的實證結果：企業社會績效能夠提升企業財務績效最後創造企業價值，而企業社會責任是一種策略性的思維，是一種價值維護甚至是創造的手段，財務績效好的公司會更有能耐去利用企業社會責任做為差異化的策略。從以上發現，本研究實證結果支持企業社會責任對於企業經營與企業價值創造有正面的效益，換言之，企業社會績效的提升對企業價值的創造是正面的。 / The relationship between corporate social performance (CSP) and corporate financial performance (CFP) is the most popular issue for the past few years. From the perspective of business administration, there is always a question aroused. “As a company investment, is it really make sense to invest corporate social responsibility (CSR) in order to increase the CSP?” In other words, is higher CSP really means higher CFP and creating more firm value? This is the central question that all the business manager will like to know. This is the topic that this research paper wants to study. Besides, this research paper not only try to understand the linkage between CSP and CFP but also try to clarify how CSP affect CFP and create firm value. 　　The methodology be used in this study is the decomposition of Tobin’s q and two-stage regression in order to avoid potential endogenous problem. After several empirical tests for the potential hypothesis, the empirical evidence shows that a higher CSP can increase CFP and create firm value in the end. Furthermore, the investment of CSR is a strategic thinking for company to preserve their firm value and create new value of the firm. The linkage between CSP and firm value is positive and should be consider as a strategy for company who want value creation.

Submitted by ANA CLAUDIA SILVA BRAGA null (anabragga@gmail.com) on 2017-08-31T16:15:53Z No. of bitstreams: 1 Tese Doutorado Ana Claudia Silva Braga.pdf: 4552779 bytes, checksum: 456de4a6fbfd60347292d8755d6c8c47 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-09-01T14:16:37Z (GMT) No. of bitstreams: 1 braga_acs_dr_sjrp.pdf: 4552779 bytes, checksum: 456de4a6fbfd60347292d8755d6c8c47 (MD5) / Made available in DSpace on 2017-09-01T14:16:37Z (GMT). No. of bitstreams: 1 braga_acs_dr_sjrp.pdf: 4552779 bytes, checksum: 456de4a6fbfd60347292d8755d6c8c47 (MD5) Previous issue date: 2017-08-04 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O vírus da hepatite C (HCV) causa a doença da Hepatite C e estima-se que cerca de 3% da população mundial esteja infectada com o vírus. A infecção por HCV promove a alteração na expressão de várias proteínas celulares. Estudos têm demonstrado que muitas proteínas de choque térmico (HSPs) possuem um perfil de expressão alterado na presença do vírus e algumas HSPs interagem diretamente com proteínas do HCV. Assim, o presente estudo teve como objetivo avaliar in vitro os níveis de expressão de proteínas de choque térmico na presença e ausência de HCV. Com este propósito, células de hepatoma humano Huh7.5 e células Huh7.5 infectadas com o vírus (HCV JFH-1) foram submetidas à extração de RNA e síntese de cDNA. A expressão diferencial de 84 HSPs e chaperonas foi avaliada por qPCR Array. Os resultados demonstram que cinco genes apresentaram expressão aumentada (em Log2 2), enquanto outros cinco apresentaram expressão reduzida. Para validar estes resultados os 10 genes diferencialmente expressos foram testados por qPCR em três modelos celulares para o HCV: células contendo replicon subgenômico do HCV (SGR-JFH-1), células infectadas com JFH-1 (ambos do genótipo 2a) e células contendo o replicon subgenômico S52 (genótipo 3). O gene HSPB8 mostrou expressão aumentada nos três modelos testados, condizente com os resultados obtidos por qPCR Array. Em seguida, promovemos o silenciamento de HSPB8 e foi observado um aumento na replicação viral. Em contraste, quando aumentamos a expressão de HSPB8, o HCV teve uma diminuição na taxa de replicação. O mesmo procedimento foi adotado para o gene DNAJC5B, validado no modelo viral genótipo 3, e o HCV mostrou padrão de replicação semelhante ao observado para o gene anterior. Esses resultados sugerem que HSPB8 pode atuar como um fator intracelular contra a replicação do vírus da hepatite C e DNAJC5B apresenta a mesma função, mas específico para o genótipo 3. Também avaliamos interações diretas com proteínas do HCV e os resultados demonstraram uma interação física entre a proteína NS4B de HCV e HSPB8. Esses resultados podem contribuir para uma melhor compreensão dos mecanismos envolvidos na replicação do HCV. / Hepatitis C virus (HCV) causes Hepatitis C disease and it is estimated that about 3% of world population are infected with the virus. HCV infection promotes alteration in the expression of several cellular proteins. Studies have shown that many heat shock proteins (HSPs) have an altered expression profile in the presence of the virus and some HSPs interact directly with HCV proteins. Thus, the present study aimed to evaluate in vitro the expression levels of heat shock proteins in the presence and absence of HCV. With this purpose, human hepatoma Huh7.5 cells and Huh7.5 cells infected with the virus (HCV JFH-1) were subjected to RNA extraction and cDNA synthesis. The differential expression of 84 HSPs and chaperones was assessed by qPCR Array. The results demonstrate that five genes showed increased expression (over Log2 2), while five other presented reduced expression. To validate these results, the 10 differentially expressed genes were tested by real-time PCR in three different HCV cell culture models: subgenomic HCV replicon cells (SGR-JFH-1), JFH-1 infected cells (both genotype 2a) and subgenomic S52 cells (genotype 3). The HSPB8 gene showed increased expression in all of three tested models, consistent with qPCR Array results. Then we promoted the silencing of HSPB8 and observed an increase in viral replication. In contrast, when we increased an expression of HSPB8, HCV had a decrease in replication rate. The same procedure was adopted for the DNAJC5B, validated in the viral model genotype 3, and HCV showed replication pattern similar to that observed for the previous gene. These results suggest that HSPB8 may act as an intracellular factor against hepatitis C virus replication and DNAJC5B have the same function, but genotype 3 specific. We also evaluated direct interactions with HCV proteins and the results demonstrated a physical interaction between the HCV NS4B protein with HSPB8. These results can contribute for a better understanding of the mechanisms involved in HCV replication. / FAPESP: 2013/17253-9

Recently, the supercritical carbon dioxide (s-CO2) Brayton cycle has been identified as a promising candidate for solar-thermal energy conversion due to its potentially high thermal efficiency (50%, for turbine inlet temperatures of ~ 1000 K). Realization of such a system requires development of solar receivers which can raise the temperature of s-CO2 by over 200 K, to a receiver outlet temperature of 1000 K. Volumetric receivers are an attractive alternative to tubular receivers due to their geometry, functionality and reduced thermal losses. A concept of a ceramic pressurized volumetric receiver for s-CO2 has been developed in this work. Computational Fluid Dynamics (CFD) analysis along with a Discrete Ordinate method (DOM) radiation heat transfer model has been carried out, and the results for temperature distribution in the receiver and the resulting thermal efficiency are presented. Issues regarding material selection for the absorber structure, window, coating, receiver body and insulation are also addressed. A modular small scale prototype with 0.5 kWth solar heat input has been designed. The design of a small scale s-CO2 loop for testing this receiver module is also presented in this work. There is a lot of ongoing investigation for design and simulation of different configurations of heat exchangers and solar receivers using s-CO2 as the working fluid, in which wall temperatures up to 1000 K are encountered. While CO2 is considered to be transparent as far as solar radiation spectrum is concerned, there may be considerable absorption of radiation in the longer wavelength range associated with radiation emission from the heated cavity walls and tubes inside the receivers. An attempt has been made, in this study, to include radiation modelling to capture the effect of absorption bands of s-CO2 and the radiative heat transfer among the equipment surfaces. As a case study, a numerical study has been performed to evaluate the contribution of radiative heat transfer as compared to convection and conduction, for s-CO2 flow through a circular pipe. The intent is to provide a guideline for future research to determine the conditions for which radiation heat transfer modelling inside the pipe can be significant, and what errors can be expected otherwise. The effect of parameters such as Reynolds number, pipe diameter, length to diameter ratio, wall emissivity and total wall heat flux has been studied. The effect of radiation modelling on wall temperatures attained for certain amount of heat flux to be transferred to s-CO2 is also studied. The resulting temperature distribution, in turn, affects the estimation of heat loss to the environment