Materiais com fases intermetálicas têm sido avaliados para aplicações estruturais em altas temperaturas devido à baixa massa específica e interessantes propriedades de resistência mecânica e resistência à oxidação de vários compostos. As ligas de Ti são reconhecidas pela sua excelente combinação de alta-resistência, baixa massa específica e alta resistência à corrosão. Tendo em vista a importância de estudos em temperaturas na faixa de 700 a 1000 oC para futuras aplicações, avaliou-se neste trabalho as relações de fases do sistema Ti-Si-B na região rica em Ti nesta faixa de temperatura. Sabendo-se que a utilização de técnicas de solidificação rápida permite a obtenção de ligas com maior homogeneidade química e microestruturas finas, utilizou-se a técnica \"splat-cooling\" de solidificação rápida para produção das amostras, no sentido de obter microestruturas de equilíbrio em tempos e temperaturas menores nos tratamentos térmicos. As técnicas de microscopia, difração de raios X, análise térmica e dureza foram utilizadas para caracterização dos materiais. O processo de solidificação rápida (\"splat cooling\") promoveu refinamento de microestrutura e formação de fase amorfa em diversas composições de liga com temperaturas de início de cristalização (Tx) na faixa de 524 a 641oC. Foram confirmadas a estabilidade das fases αTi, Ti6Si2B e Ti3Si a 700oC e 1000oC. Os valores de dureza dos discos solidificados rapidamente ficaram na faixa de 434 HV a 1207 HV. / Materials with intermetallic phases have been evaluated for structural applications at high temperatures due to low specific mass and attractive mechanical properties as high-strength and oxidation resistance of various compounds. Ti alloys are recognized for their excellent combination of high-strength, low specific mass and high oxidation resistance. About future applications, studies at temperatures ranging from 700 to 1000 oC are important, we evaluated in this work the phase relationships of the system Ti-Si-B in the Ti-rich region in this temperature range. Knowing that the use of rapid solidification techniques results in alloys with higher chemical homogeneity and fine microstructure, the \"splat-cooling\" technique was used to produce the samples, in order to obtain stable microstructures in lower times and temperatures at the heat treatment. Microscopy, X-ray diffraction, thermal analysis and hardness measurement techniques were used for the materials characterization. The rapid solidification - splat cooling promoted the refinement of microstructure and even the formation of amorphous phase in the microstructure of materials with initial temperatures of crystallization (Tx) in the range from 524 to 641oC. We confirmed the stability of the phases αTi, Ti6Si2B and Ti3Si at 700oC and 1000oC. The hardness of the rapidly solidified discs were in the range of 434 HV to 1207 HV.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This thesis is based in an ethnografic research developed throughout twelve months with people who participate in two distinct genres of gyms in Santa Maria (RS): Outdoors Gym and Fitness Gym. This work has as its objective to analyze the activities done by people who exercise in both modalities as technologies of the self, from the concept discussed by Michel Foucault. Based on observations in the field, evident differences were found in the way the physical activities are done. Among the practitioners in the Outdoors Gym, the exercises are performed to treat an existing illness or to prevent a future illness, in this genre, physical activities are performed while talking and pleasantry exchanging, without the help of physical education professionals, which highlights sociability as a significant aspect of the use of this gym to these people. On the other hand, in Fitness Gyms, the physical activities are performed aiming to obtain a greater physical conditioning and body muscle, reflecting aesthetics concern. Physical exercise is done through professional body expertise knowledge, in which people do a series of training with the aim to maximize results in the gym. Therefore, research has identified the use of two models of gym, encouraged by different agents, as a way to influence personal behavior. / Esta dissertação fundamenta-se numa pesquisa etnográfica desenvolvida durante dozes meses com pessoas que fazem uso de duas modalidades distintas de academias em Santa Maria (RS): Academia ao Ar Livre e Academia de Ginástica e Musculação. O trabalho tem como objetivo analisar, as atividades exercidas por pessoas que realizam atividades físicas nas duas modalidades de academia como técnicas de si, partindo do conceito discutido por Michel Foucault. Com base nas observações em campo foram constatadas diferenças evidentes nos modos como as atividades físicas são realizadas. Entre as praticantes da Academia ao Ar Livre os exercícios físicos são efetuados para tratar de uma doença existente ou para prevenir uma futura enfermidade, nesta modalidade às atividades físicas são realizadas em meio a conversas e brincadeiras, sem o auxílio de profissionais da educação física, o que ressalta a sociabilidade como um aspecto significativo para o uso da academia para estas pessoas. Por outro lado, na Academia de Ginástica e Musculação as atividades físicas são realizadas visando obter maior condicionamento físico e musculatura corporal, refletindo preocupação com a estética. Os exercícios físicos são realizados através dos conhecimentos de profissionais da expertise do corpo, no qual as pessoas realizam séries de treinos com a finalidade de maximizar os resultados esperados com o uso da academia. Portanto, a pesquisa identificou que a utilização dos dois modelos de academias é incentivada por diferentes agentes, de modo a influenciar nas condutas das pessoas.

Le but de cette thèse est la définition de la construction avec aunque, la sélection modale qui y est opérée et l’analyse de deux traductions possibles en français : la construction avec bien que et la construction avec même si. Après un examen des différentes propositions explicatives qui ont essayé de rendre compte de cette construction, il apparaît que ce qui définit une construction du type A aunque B est la présupposition d’une relation implicative sous-jacente selon laquelle la déclaration A implique l’absence de la déclaration B. La sélection modale opérée dans la proposition en aunque est expliquée au moyen de l’opposition qui s’établit en langue entre un mode de type actualisant [canto, canté, cantaré] et un mode de type inactualisant [cantaba, cantaría, cante, cantara]. Cette nouvelle description des formes du système verbal espagnol permet non seulement de fournir une explication plus simple et plus générale, mais aussi plus objective du mode qui est employé dans ce type de propositions. La traduction de celle-ci exige que l’on tienne compte de la valeur spécifique des formes verbales qui suivent aunque et de celle qu’il faut accorder en langue aux locutions conjonctives bien que et même si. / The objective of the present thesis is to define the construction with aunque, to study the modal selection involved in that construction, and to analyse two possible translations for it in French : the construction with bien que, and the construction with même si. After reviewing the various explanations proposed to account for the construction under study, it turns out that what defines a construction such as A aunque B is the presupposition of an underlying implicative relation according to which statement A implies the absence of statement B. The modal selection carried out in the clause with aunque is explained thanks to the opposition emerging in Spanish language between an actualising mode [canto, canté, cantaré] and a non-actualising mode [cantaba, cantaría, cante, cantara]. This new description of the forms of the verbal system in Spanish leads not only to a simpler, more general explanation of the mode used in this type of clauses, but also to a more objective one. The translation of such clauses entails taking into account the specific value of the verbal forms following aunque as well as the value to be attributed in language French to the phrasal conjunctions bien que and même si.

Lithium-Ionen-Batterien besitzen ein ausgezeichnetes Potential für die Energiespeicherung. Das derzeit dominierende Anodenmaterial in Lithium-Ionen-Batterien mit einer Energiespeicherkapazität von 339 mAh/g ist Graphit. Als Alternative hierfür bieten sich Lithiumsilicide und Lithiumstannide an. Diese Materialien zeichnen sich durch eine viel größere Speicherkapazität und geringere Selbstentladungspotentiale aus. Für die kommerzielle Anwendung dieser beiden Systeme in Lithium-Ionen-Batterien werden grundlegende und verlässliche thermodynamische Daten benötigt. Derzeit ist die Existenz von sieben Lithiumsiliciden sicher nachgewiesen. Dazu zählen die sechs stabilen Phasen Li17Si4, Li16.42Si4, Li13Si4, Li7Si3, Li12Si7, die Hochdruckphase LiSi und die metastabile Phase Li15Si4. Für die ersten fünf genannten Phasen wurden in der ersten Förderperiode des Schwerpunktprogrammes 1473 Wärmekapazitäten und Standardentropien bestimmt. Bei den Lithiumstanniden sind derzeit sieben Phasen gesichert belegt. Allerdings existiert für keine Phase der Lithiumstannide ein verlässlicher thermodynamischer Basisdatensatz. Aus diesem Grund wurden für die beiden zuletzt genannten Lithiumsilicide (Li15Si4 und LiSi), sowie für die Lithiumstannide Li17Sn4, Li7Sn2, Li13Sn5 und Li7Sn3 die fehlenden thermodynamischen Daten experimentell bestimmt. Die hergestellten Phasen wurden zunächst mittels Röntgenbeugung, thermischer und chemischer Analyse charakterisiert. Ein Schwerpunkt dieser Arbeit lag auf der experimentellen Bestimmung der Wärmekapazitäten in einem Temperaturbereich von 2 K bis zur jeweiligen Zersetzungstemperatur der untersuchten Verbindungen. Hierfür wurden zwei unterschiedliche Kalorimeter verwendet: ein Physical Property Measurement System (Quantum Design) von 2 K bis 300 K und eine DSC 111 (Setaram), beginnend ab 300 K. Die experimentellen Daten konnten mit Messunsicherheiten von 1 % bis 2 % über 20 K und bis zu 20 % unterhalb von 20 K angegeben werden. Die Messungen bei niedrigen Temperaturen erlauben zudem die Berechnung der Standardentropien, sowie die Bestimmung von elektronischen Beiträgen und Gitterschwingungsbeiträgen zur Wärmekapazität. Weiterhin ist Fokus dieser Arbeit die Bestimmung der Standardbildungsenthalpien der Lithiumsilicide und Lithiumstannide auf Basis von Wasserstoffsorptionsmessungen mittels einer Sieverts-Apparatur. Hierfür wurden erstmals Messungen an den Lithiumsiliciden ausgehend von Li17Si4, LiH:Si (Li:Si = 17:4), Li16.42Si4 und LiSi durchgeführt. Für die Lithiumstannide dienten als Ausgangsmaterial Li17Sn4, LiH:Sn (Li:Sn =17:4), sowie Li7Sn2 und LiH:Sn (Li:Sn = 7:2). Die Anwendung des van´t-Hoff-Plots resultierte in Messunsicherheiten von mindestens 10 %. Aus diesem Grund wurde eine alternative Auswertemethode gewählt, bei der die ermittelten Wärmekapazitäten und Standardentropien mit den Gleichgewichtsdrücken aus den Wasserstoffsorptionsmessungen miteinander verknüpft werden. Auf diese Weise konnten Standardbildungsenthalpien für die untersuchten Phasen mit Fehlern kleiner 1 % ermittelt werden. Aus den Ergebnissen dieser Arbeit resultierte ein vollständiger, gesicherter thermodynamischer Datensatz für das System Li-Si. Das berechnete Li-Si-Phasendiagramm ist im sehr guten Einklang mit experimentellen literaturbekannten Daten. Für die Lithiumstannide erfolgte eine Validierung der ermittelten thermodynamischen Werte. Die in dieser Arbeit erzielten Ergebnisse liefern einen wesentlichen Beitrag zur Verbesserung der Datenbasis für thermodynamische Berechnungen und für das Verständnis von Phasensequenzen und Gleichgewichten beim Einsatz von Lithiumsiliciden bzw. Lithiumstanniden als Anodenmaterialien in Lithium-Ionen-Batterien.

There are great energy savings to be made by recycling aluminium; as little as 5% of the energy needed for primary aluminium production may be required. Striving to produce high quality aluminium castings requires knowledge of microstructural imperfections, which is extra important when casting recycled aluminium that generally contains higher levels of imperfections compared to primary aluminium. Imperfections include amongst others Si, Fe, and Mn as well as oxides. Si is needed for castability, but it may also initiate fracture. There are different types of Fe-rich intermetallics influencing properties of castings, generally in a negative direction. Oxides constitute cracks and they are elusive because they are difficult to quantify. This thesis aims to increase knowledge about imperfections in recycled aluminium castings originating from alloying elements and the melt. Experiments were performed in advanced laboratory equipment, including X-radiographic imaging during solidification and in-situ tensile testing in a scanning electron microscope. Experiments were also performed at industrial foundry facilities. The experiments showed that the nucleation temperature of primary α-Fe intermetallics increased with higher Fe, Mn, and Cr contents. Primary α-Fe are strongly suggested to nucleate on oxides and to grow in four basic morphologies. Lower nucleation frequency of α-Fe promoted faster growth and hopper crystals while higher nucleation frequency promoted slower growth rates and massive crystals. Results also showed that a decrease in the size of the eutectic Si and plate-like β-Fe intermetallics improved tensile properties, foremost the elongation to fracture. In β-Fe containing alloys the transversely oriented intermetallics initiated macrocracks that are potential fracture initiation sites. In alloys with primary α-Fe foremost clusters of intermetallics promoted macrocracks. In fatigue testing, a transition from β-Fe to α-Fe shifted the initiation sites from oxides and pores to the α-Fe, resulting in a decrease of fatigue strength. Oxides in Al-Si alloys continue to be elusive; no correlations between efforts to quantify the oxides and tensile properties could be observed. / Genom att återvinna aluminium kan stora energibesparingar göras eftersom återvinning kan förbruka så lite som 5% av den energi som behövs för produktion av primär aluminium. Vid gjutning av högkvalitativa aluminiumprodukter krävs förståelse för defekter i mikrostrukturen och denna kunskap är extra viktig vid användning av återvunnen aluminium, som i regel innehåller mer defekter än primär aluminium. Defekterna består bland annat av Si, Fe och Mn samt oxider. Si behövs för gjutbarhet men kan också initiera brott. Järnrika intermetaller kan ha olika morfologier som generellt påverkar gjutna komponenter negativt. Oxider, som kan utgöra sprickor, är gäckande då de är svåra att kvantifiera. Denna avhandlings syfte är att öka kunskapen om defekter i gjutna komponenter av återvunnen aluminium. Experiment utfördes med avancerad laborationsutrustning så som röntgenfotografering av prover under stelning och dragprovning i svepelektronmikroskop. Experiment utfördes också i industrimiljö. Experimenten visade att kärnbildningstemperaturen steg för primära α-Fe intermetaller med ökade andelar av Fe, Mn och Cr. Resultaten tyder starkt på att primär α-Fe kärnbildas på oxider och att de växer i fyra olika morfologier. Lägre kärnbildningstäthet av α-Fe främjade snabbare tillväxt av kristaller med håligheter men högre kärnbildningstäthet främjade långsammare tillväxt av massiva kristaller. Resultaten visade också att minskad storlek av eutektiskt Si och β-Fe intermetaller ledde till förbättring av dragprovsresultaten, främst brottförlängningen. I legeringar med β-Fe ledde transversellt orienterade intermetaller till makrosprickor vilka kan initiera brott. I legeringar med primär α-Fe var det främst kluster av intermetaller som orsakade makrosprickor. I utmattningsprovning orsakade modifiering av β-Fe till α-Fe förflyttning av sprickinitieringen från oxider och porer till α-Fe, vilket resulterade i en reducerad utmattningshållfasthet. Oxiderna i Al-Si-legeringar fortsätter att gäcka; ingen korrelation mellan försök att kvantifiera oxiderna och draghållfasthet kunde påvisas.

La forme en -re, dite « futur du subjonctif » (cantare), tombée en désuétude dans la langue standard espagnole, s’observe toujours dans le discours juridique. Dans cette étude, nous faisons l’hypothèse que la forme en -re survit car elle a une utilité pour la communauté des sujets parlants juristes. Adhérant à la linguistique du signifiant, dans la tradition guillaumienne, nous posons que cette utilité découle du signifié de la forme en -re. Notre corpus est composé de plusieurs documents juridiques qui représentent les cinq étapes du système modal définies par Gilles Luquet (1988). Nous choisissons les hypothèses en si car les experts ne s’accordent pas sur les alternatives légitimes de la forme en -re dans les protases de ces hypothèses. Les exemples collectés de ces documents, analysés au regard de la linguistique du signifiant, nous permettent de faire quatre conclusions : 1) l’alternance entre la forme en –se et la forme en -re dans les protases existe depuis le Moyen Âge ; 2) la forme en -re et ses alternatives ont des fonctions pragmatiques : elles contribuent à la cohérence du texte et elles permettent au juriste de faire progresser ourégresser l’argument du texte (fonction déictique) ; 3) la morphologie verbale des apodoses semble fortement liée au sous-genre juridique ; 4) cette étude de la forme en -re et ses alternances dans les hypothèses en si, jette la lumière sur la particularité du morphème si : étant élément du système espagnol d’affirmation, si ramène le perspectif de l’énoncé au présent, permettant au juriste de regarder la situation depuis le non-révolu (forme en -re) ou le révolu (la forme en -se) sans perdre la cohérence de son texte. / The -re form, or “future subjunctive” (cantare), is obsolete in Modern Standard Spanish, yet is still observed in legal literature. In this dissertation, we made the hypothesis that the -re form has survived because it is useful for the community of speakers who interact with legal literature. Using the theory of the linguistique du signifiant, we postulated that the different uses of the -re form are linked its signifier. To test ourhypothesis, we composed a corpus of several legal documents. They represent of each of the five epochs of the Spanish mode system defined by Gilles Luquet (1988). We chose to examine the role of this verb form in the protases of si-clauses because experts do not agree on the legitimate alternative verb forms in this syntax. After the observation and analysis of the examples collected, we made four conclusions. Firstly, the alteration between the -se form and the -re form in protases of si-clauses dates from the Middle Ages. Secondly, the -re form and its alternatives have pragmatic uses: they contribute to textual organization and allow the jurist to move backwards and forwards in the construction of his or herarguments (deictic function). Thirdly, the verbal morphology of the apodoses seems strongly linked with the legal subgenre of the documents. Fourth and finally, our study of the -re form and its alternatives sheds light on the specificities of the morpheme si: because it is part of the Spanish affirmation system, the morpheme si always brings the speaker’s perspective back to the present, allowing the jurist to observe the event unfold from a point in the non-past (-re form) or the past (-se form) without disrupting the text’scoherence.

Si nanowires have potential applications in a variety of technologies such as micro and nanoelectronics, sensors, electrodes and photovoltaic applications due to their size and specific surface area. Au particle-assisted vapour-liquid-solid or VLS growth method remains the dominant process for Si nanowire growth. A comprehensive kinetic model that addresses all experimental observations and provides a physico-chemical model of the VLS growth method is thus essential. The work done as part of this research is divided into two sections. A steady state kinetic model was first developed for the steady state growth rate of Si nanowires using SiCl4 and SiH4 as precursors. The steady state refers to a balance between the rates of injection and ejection of Si into the Au droplet. This balance results in a steady state supersaturation under which wire growth proceeds. In particular evaporation and reverse reaction of Si from the Au droplet and modes of crystal growth for wire growth have been considered in detail for the first time. The model is able to account for both, the radius independent and radius dependent growth rates reported in the literature. It also shows that the radius dependence previously attributed to purely thermodynamic considerations could also as well be explained just by steady state kinetics alone. Expressions have been derived for the steady state growth rate that require the desolvation energy, activation energy for precursor dissociation and supersaturation prevalent in the particle as inputs for calculation. In order to evaluate this model the incubation and growth of Si nanowires were studied on sapphire substrates in an indigenously built automated MOCVD reactor. Sapphire was chosen as the substrate, as opposed to Si which is commonly used, so as to ensure that the vapour phase is the only source of Si. A classical incubation period for nucleation, of the order of 4-8 minutes, was experimentally observed for the first time. Using the change in this incubation period with temperature a value of 15kT was determined to be the desolvation energy for growth using SiH4. The steady state growth rate of Si nanowires were measured and compared with the predictions of the model using the values of activation energies so determined. The thesis based on the current research work is organized as follows: Chapter 1 introduces the research area followed by a brief outline of the overall work Chapter 2 provides a summary of current literature, and puts the research described in this thesis in perspective. The diameter dependent growth rate of NWs which was initially solely attributed to the Gibbs-Thomson effect is first summarized. Experimental observations to the contrary are then highlighted. These contradictions provided the incentive for the research described in this thesis. Following a summary of the growth rate theories, the experimental observations on incubation available in the literature are summarized. All the other variants of the VLS method are also discussed. Chapter 3 describes the design, construction and working of an indigenously built semi- automated CVD reactor. This CVD reactor was used to conduct the Si NW growth experiments over sapphire substrates. Chapter 4 develops the physical chemistry model for Au catalyzed Si nanowire growth using SiCl4 and SiH4 precursors. The model originated from the contradictions present in the literature over the rate limiting step of the VLS growth mechanism and the steady state growth rate dependence on wire diameter. The development starts with explaining the thermodynamics of the steady state VLS process. The significance of the model lies in the detailed analysis of the all the atomistic process occurring during the VLS growth. In particular the evaporation and reverse reaction of Si from Au-Si droplet is explained in detail and possibly for the first time. Expressions for steady state growth rate by various modes, such as layer by layer growth (LL), by multilayer growth (ML) and growth by movement of a rough interface at the L-S growth interface are derived and presented. Chapter 5 discusses the results which emerge out the kinetic model from the previous chapter. Under a single framework of equations, the model is successful in explaining both the diameter independent and diameter dependent growth of NWs. As one of the major outcomes of the model, the growth rates of Si NWs are predicted and trends in growth rate are found to agree with those experimentally observed. Growth rate dependencies on pressure and temperature are implicitly included in the equations derived. An estimate of supersaturation has been extracted for the first time using the framework of equations. Chapter 6 contains the experimental results of the Si NW growth over sapphire substrates. An incubation period in the order of 3-8 minutes has been observed for Si NW growth on sapphire. The data has been compared with existing literature data and interpreted using classical transient nucleation theory. The incubation period data has been utilized to extract the kinetic parameter, QD, which is the desolvation enegy. These parameters and the measured steady state growth rates have been used to estimate the supersaturation existing in the droplet using the framework developed in chapters 4 and 5. Chapter 7 summarizes the outcome of the current research and highlights the future directions for the research problem addressed in this thesis.

Les composites à matrice céramique ou carbone sont des matériaux de structure pour des applications à haute température. Ils sont constitués d’un renfort fibreux enrobé d’une matrice. Cette dernière est obtenue par infiltration chimique en phase vapeur. Une préforme, fibreuse avec ou sans une première matrice, est placée dans un four dans lequel sont injectés des gaz dit précurseurs. Leur réaction hétérogène avec la préforme est à l’origine de la formation matricielle. Cette thèse a été motivée par la nécessite d’optimiser via une modélisation numérique ce procédé long et couteux.Deux programmes ont dès lors été développés puis validés. Chacun est dédié à une échelle spécifique du matériau : microscopique (fibre) et macroscopique (composite). Ils s’appuient tout deux sur des algorithmes de marche aléatoire et requièrent des représentations tridimensionnelles de la préforme. Dans cette optique, des images tomographiques de préformes de composites C/C et SiC/SiC ont été acquises aux deux échelles souhaitées. Le code propre à l’échelle de la fibre a été utilisé pour déterminer les propriétés géométriques, diffusives et réactives dans plusieurs zones de l’image afférente. Des corrélations entre ces propriétés ont été mises en place puis intégrées dans le code afférent à l’échelle du matériau pour infiltration numérique.Dans le cas des composites C/C, cet outil multi-échelle a été couplé à un modèle chimique permettant d’anticiper, en fonction des conditions opératoires, l’épaisseur ainsi que la microtexture de la matrice déposée. Des prévisions de densification ont également été employées pour qualifier et comparer l’infiltrabilité de plusieurs composites SiC/SiC. / Ceramic matrix composites and carbon fiber reinforced carbon composites are dedicated to high temperature applications. They consist of a stacked fibrous arrangement, woven or not, coated by matrix. Chemical Vapor Infiltration (CVI) is a popular processing route, where a preform (fibers with or without a first matrix) is placed inside a furnace. Precursor gases are then injected, enter the preform and generate matrix formation by heterogeneous chemical reaction. Experimental optimization of CVI is long and costly, triggering the need for a numerical model. The creation of such a tool has been the objective set for this thesis.Two programs were first developed and validated. Each is linked to a specific material scale: microscopic (fiber scale) and macroscopic (composite scale). Both are based on a random walk algorithm and require three-dimensional representations of the preform. X-ray tomography scans of C/C and SiC/SiC composite preforms were performed at the desired scales. The fiber scale program was used for computation of geometrical, diffusive and reactive properties in several regions of the relevant image. Correlations between these properties are created and inserted into the composite scale program for numerical infiltration.In the case of C/C composites, this multi-scale tool was coupled to a chemical model for anticipation, under various operating conditions, of matrix thickness and microtexture. Densification previsions on different SiC/SiC composites enabled their direct measure and comparison of their infiltrability.

In this work are discussed photovoltaic cells. There are also discussed basic concepts of radiation source for solar cells. Also mentioned the issue of semiconductors and even the history and evolution of the solar cells. A large part deals with possibilities of photovoltaic cells degradation. In one chapter is an attempt to bring some types of photovoltaic cells and a description of the production of these modules.The practical part deals with photovoltaic modules degradation and its evaluation. Following part compares measured values with the values provided by producer of photovoltaic modules.

The aim of this paper is to compare a bottom filling of a ceramic form made by lost wax process and a top filling conventional method. A computer simulation of filling and casting solidification will contribute to this comparison. The comparison includes evaluation of readings DAS and characteristic readings of porosity with chosen varieties of casting. The results show that the readings DAS did not change much but characteristic readings of porosity were much better at bottom filling. The computer simulation also showed a certain contribution in the field of model smelting technology.