O presente trabalho apresenta uma análise numérica do desempenho térmico de painéis construídos utilizando o sistema light steel framing (LSF) submetido a ação térmica decorrente de um incêndio. O objeto de estudo foram painéis utilizados na construção de duas casas modelo localizadas na Universidade Tecnológica Federal do Paraná campus Curitiba, construídas com materiais disponíveis comercialmente no Brasil e as análises utilizaram propriedades disponibilizadas pelos fabricantes e pela norma brasileira. A análise numérica foi realizada no software ANSYS, com base no método dos elementos finitos em análise térmica transiente. O modelo foi validado com base em comparação com análises experimentais pesquisadas na literatura. Quatro painéis obtidos das casas modelo foram analisados. Os painéis que utilizaram lã de PET para preenchimento da cavidade foram também analisados com preenchimento de lã de vidro. Um painel simples, com a cavidade preenchida por ar foi analisado para ser usado como referência. Por fim, com a utilização de coeficientes de redução da resistência ao escoamento propostos pela ABNT NBR 14323:2001, determinou-se a redução da resistência do aço do perfil de acordo com o tempo de exposição ao incendio e o tempo de resistência ao fogo dos perfis. Com base nos resultados obtidos é possível afirmar que mesmo para os paneis com pior desempenho, a proteção obtida pode ser suficiente, a depender do carregamento aplicado ao montante e do Tempo requerido de resistência ao fogo necessário. O presente trabalho apresenta informação relevante sobre o desempenho térmico em situação de incêndio do sistema LSF constituído com materiais brasileiros. / The thermal performance of light steel framing (LSF) panels was the objective of this study. The study subject was panels used in the construction of two model houses located at Federal Technology University – Parana, built with materials commercially available in Brazil. The analysis was set with material properties from the manufacturer and in compliance with the Brazilian regulation, using the finite element method for a transient thermal analysis. The model validation was based on experimental tests available in the literature. Based on the validated model, the four panels have been analyzed. Two of the panels used PET wool in the cavity for insulation and the analysis was repeated with them replacing it for glass wool. A panel with no insulation was also analyzed to be used as reference. Based on the analysis results and the resistance reduction coefficients proposed by ABNT NBR 14323:2001, the resistance decrease of the studs due to the fire exposure and the panels resistance to fire were determined. Based on the obtained results, it can be affirmed that, depending on the applied load and the required Equivalent time of fire exposure, even the less protective configuration of the panels presented can be viable. The current study presented relevant information about the performance of LSF manufactured in Brazil when exposed to fire.

Thesis (D. Tech.) -- Central University of Technology, Free State, 2009 / Superficial cancerous lesions are commonly treated through low energy X-ray or electron radiation in radiotherapy. The treatment units that produce the radiation are equipped with square, rectangular and round applicators of different sizes. These applicators attach to the treatment units and define the radiation field size applied during treatment. An applicator is chosen to fit the shape of the cancerous lesion on the patient as closely as possible. Since cancerous lesions are irregular in shape, there will always be an area of healthy tissue between the edge of the lesion and the edge of the standard field shape. This healthy tissue will be irradiated along with the lesion during treatment which is undesirable since the cancer wound heals through reparative growth of the surrounding healthy tissue after treatment. Traditional techniques that were developed to shield this healthy tissue and thus shape the radiation field to the shape of the lesion present various shortcomings. This study introduces a new thermal-spray process for producing radiation field shaping shields which overcomes most of the shortcomings encountered with the traditional field shaping techniques. Since none of the commercially available thermal-spray equipment could be used to produce field shaping shields, new thermal-spray equipment was designed and fabricated tailor made to the application. Different techniques to determine the contours of the treatment area on the patient were investigated. These included a patient contact technique using a plaster bandage impression and a non-contact technique using 3D laser scanning. From the plaster bandage impression a plaster model can be produced onto which a high density low melt material such as Wood’ s alloy can be thermally sprayed to produce a field shaping mask. A model can also be produced from the 3D laser scanning data through laser sintering (LS) in nylon polyamide powder or through computer numerical controlled (CNC) milling in a block of low density polyurethane. The thermal-spray technique was evaluated by comparing the field shaping ability of radiation shields produced through the technique to the field shaping ability of shields produced through the traditional techniques. Radiographic film was used for this purpose and the results are presented in the form of isodensity charts. The required thicknesses of thermal-sprayed field shaping masks to shield radiation of various energies were also determined. The thicknesses were determined through radiation transmission measurements of known thicknesses of sprayed sheets of Wood’ s alloy. X-ray imaging showed that there were no defects present within thermal-sprayed layers of Wood’ s alloy that may negatively affect the shielding ability of masks produced through the technique.

Thesis (M. Tech. (Mech. Eng.)) -- Central University of Technology, Free state, 2010 / The purpose of this research is to minimize the use of active systems in providing thermal comfort in single-family detached, middle to high income residential buildings in Bloemfontein. The typical case study house was selected according to the criteria as reviewed by Mathews et al., (1999). Measurements were taken for seven days (18 – 24 May 2009). The measurements were carried out in the winter period for Bloemfontein, South Africa. Ecolog TH1, humidity and temperature data logger was used in doing the measurements. These measurements included indoor temperatures and indoor relative humidity. Temperature swings of 8.43 ºC and thermal lag of 1 hour were observed. For the period of seven days (168 hours), the house was thermally comfortable for 84 hours. Thermal analysis for the base case house was done using Ecotect™ (building analysis software) and the simulated results were compared with the measured results. A mean bias error (MBE) of between 10.3% ≤≤11.5% was obtained on the initial calibration. The final calibration of the model yielded error between0.364% ≤≤0.365%. The final calibration model which presented a small error was adopted as the base case. Passive strategies were incorporated to the Ecotect™ model (final calibrated model) singly and in combination; then both thermal and space load simulations were obtained and compared to simulations from the original situation (base case) for assessing improvements in terms of thermal comfort and heating, ventilation and air conditioning (HVAC) energy consumption. Annual HVAC electricity savings of up to 55.2 % were obtained from incorporating passive strategies in combination. Incorporating passive strategies resulted in small improvements in thermal comfort.

Hot water discharges and potential chemical spills are factors that threaten water quality in cooling reservoirs of chemical and power plants. In this thesis, three models are used to analyze the impact of these factors in a particular case study.

L’incorporation de sous-produits agricoles ou de matériaux naturels dans la matrice cimentaire confère des propriétés intéressantes aux composites élaborés. L’objectif de cette thèse est d’élaborer un matériau pouvant répondre aux exigences mécaniques, thermiques et de durabilité des matériaux de construction en zone tropicale humide. Dans un premier temps, l’activité pouzzolanique d’une pouzzolane naturelle, de cendres de tronc de bambou et de cendres de bagasse de canne à sucre ont été évaluées. L’influence de leur incorporation a été ensuite étudiée sur les propriétés mécaniques et la durabilité des mortiers exposés à des ions chlorures et sulfates. Dans un second temps, l’influence de l’ajout de fibres de bagasse sur les propriétés thermiques et mécaniques des composites a été étudiée en fonction de différents paramètres (teneur en fibres, environnement de vieillissement, type de matrice cimentaire).Les résultats obtenus ont permis de montrer que les matériaux étudiés possèdent une activité pouzzolanique et qu’il est possible de les incorporer au ciment afin de lutter contre la corrosion. De plus, les composites élaborés avec des fibres de bagasse sont plus isolants que ceux élaborés sans fibres. Cependant, du point de vue des propriétés mécaniques, l’incorporation de fibres de bagasse diminue les contraintes à la flexion des composites. / The incorporation of crop wastes or natural materials in the cement matrix confers interesting properties to composites prepared. The aim of this thesis is to develop a material that can reach the mechanical, thermal and durability requirements for building materials in the humid tropical zone. Firstly, pozzolanic activity of a natural pozzolan, bamboo stem and sugar cane bagasse ashes has been determined. Influence of their incorporation on mechanical properties and durability of mortars exposed to chloride and sulphate ions was studied. Secondly, influence of addition of bagasse fibers on thermal and mechanical properties of composites was studied as a function of various parameters (fibers content, curing, type of cement matrix).These results has shown that the materials studied have pozzolanic activity and it is possible to incorporate them into the cement to fight against corrosion. Moreover, composites elaborated with bagasse fibers are more insulating than those elaborated without fibers. However, from the viewpoint of mechanical properties, incorporation of bagasse fibers decreases flexural strength of composites in the present work and under the conditions producing procedures that were adopted.

Cette thèse présente la conception et l'implémentation d'une nouvelle génération de puces à atomes, ouvrant de nouvelles perspectives expérimentales dans des micropièges magnétiques très anisotropes. Les propriétés thermiques des puces en nitrure d'aluminium sont étudiées en détail. Le dispositif a été optimisé pour piéger de plus grands nombres d'atomes et améliorer la qualité de l'imagerie, notamment en fabriquant un miroir de planéité sub-λ/10 à la surface de la puce.Nous étudions des gaz quasi-1D grâce à des images in situ de profils fluctuants et des méthodes précises de calibration et d'analyse statistique. Nous mesurons des fluctuations non-gaussiennes, ce qui permet de tester sensiblement la thermodynamique du gaz et donne une mesure de corrélations à trois corps. Nous étudions précisément la transition de quasicondensation et mesurons pour la première fois sa loi d'échelle. En régime 3D, c'est une condensation transverse qui déclenche la quasicondensation longitudinale, tandis qu'en régime 1D, la formation d'un quasicondensat est gouvernée par les interactions répulsives et non par la dégénérescence quantique.Obtenant des températures record pour des gaz 1D, nous observons des fluctuations subpoissoniennes lorsque les corrélations atomiques sont déterminées, au moins localement, par les fluctuations quantiques qui dominent les fluctuations thermiques. Nous discutons également la thermalisation étonnamment rapide mesurée en régime 1D profond qui suggère que des collisions effectives à 3 corps brisent l'intégrabilité du système. / This thesis presents the design and implementation of a new generation of atom chips, that open novel experimental possibilities with very anisotropic magnetic microtraps. The thermal properties of aluminum nitride atom chips are studied in detail. We have optimized the set-up in order to trap more atoms and image the clouds as precisely as possible. In particular we have fabricated a miror of sub-λ/10 planeity on top of the chip surface.We study quasi-1D gases using in situ pictures of the fluctuating density pro_les and precise methods for their calibration and statistical analysis. We measure non-gaussian fluctuations, which provides a sensitive test of the thermodynamics of the system and gives a measure of three-body correlations. We study precisely the quasicondensation transition, measuring its scaling for the first time. In the 3D regime, a transverse condensation triggers the longitudinal quasicondensation. In the 1D regime, on the contrary, the appearance of a quasicondensate is governed by repulsive interactions only, and not by quantum degeneracy.Reaching record temperatures for 1D gases, we observe subpoissonian fluctuations which indicate that atomic correlations are determined at least locally by quantum rather than thermal fluctuations. We also discuss our observation of surprizingly e_fficient thermalization deep in the 1D regime, suggesting that e_ffective 3-body collisions break the integrability of the system.

Le secteur du bâtiment représente 35% des la consommations énergétiques dans les pays membres de l’agence international de l’énergie en 2010 et 39,8% aux Etats-Unis en 2015. Plus de 50% de cette consommation a été utilisée pour la production de chaleur et de froid. Néanmoins cette consommation peut être réduite par l'amélioration la performance énergétique du bâtiment. La performance thermique de l'enveloppe du bâtiment joue un rôle primordial. Par conséquent, le diagnostic thermique de l'enveloppe du bâtiment est nécessaire pour, par exemple, la réception de nouvelles constructions, l'amélioration de la performance énergétique des anciens bâtiments, ainsi que la vente et la location des logements. Pourtant, il existe très peu de méthodes quantitatives pour la caractérisation des parois épaisses. L'objectif de cette étude est d'explorer des méthodes quantitatives innovantes de diagnostic thermique de l'enveloppe du bâtiment. Des mesures expérimentales ont été réalisées en laboratoire (à l’IFSTTAR à Nantes) et in situ (à l’IUT de Bordeaux). Différents capteurs et méthodes d'instrumentation ont été étudiés pour mesurer la densité de flux et la température de surfaces des parois, afin de procurer des recommandations pour le choix des capteurs ainsi que des protocoles de traitement de données. A partir des données mesurées (température et densité de flux des surfaces de l'enveloppe), trois approches numériques ont été proposées pour estimer des paramètres thermiques des parois multicouches épaisses : par méthode inverse, par réponse à un échelon et par réponse impulsionnelle. En outre, une méthode innovante non-destructive utilisant la rayonnement térahertz a été étudiée. Les mesures ont été effectuées au sein du laboratoire I2M. Cette méthode permet de caractériser le coefficient d'absorption des matériaux constructifs ordinaires comme isolation, plâtre, béton, bois… Elle pourrait postérieurement être combinée avec une méthode thermique pour apporter des informations complémentaires. / Buildings represent a large share in terms of energy consumption, such as 35% in the member countries of IEA (2010) and 39.8% in U.S. (2015). Climate controlling (space heating and space cooling) occupies more than half of the consumption. While this consumption can be reduced by improving the building energy efficiency, in which the thermal performance of building envelope plays a critical role. Therefore, the thermal diagnosis of building envelope is of great important, for example, in the case of new building accreditation, retrofitting energy efficiency of old building and the building resale and renting. However, very few diagnostic methods exist for the characterization of thick walls. The present measurement standards that based on steady state heat transfer regime need a long time (several days). The classical transient technologies, such as flash method, are difficult to implement on the walls because of the large thickness of walls and the complex conditions in situ. This thesis aims to explore innovative methodologies for thermal quantitative diagnosis of building envelope. Two experimental cases were carried out: one is in laboratory (IFSTTAR, Nantes) and the other is in situ (IUT, Bordeaux). Different sensors and instruments were studied to measure the wall heat flux and surface temperature, and provided some guidelines for the choice of sensors and data processing protocols as well. Using these measured data, three estimation approaches were proposed to estimate the thermal parameters of the multilayer thick wall: pulse response curve method, step response curve method and inverse method, which can be applied for different diagnostic situations. In addition, an innovative NDE (non-destructive evaluation) method using terahertz (THz) radiation was also investigated. Measurements were carried out in I2M laboratory to characterize the absorption coefficient of standard building materials (insulation, plaster, concrete, wood ...). This THz method can be combined with a previous thermal method to provide some complementary information.

Depuis de nombreuses années, la société est de plus en plus consommatrice d’énergie. Cette augmentation va de pair avec les progrès d’accès à l’énergie, une croissance démographique mondiale continue, l’amélioration de la qualité de vie et le développement de nouvelles technologies. D’après l’agence internationale de l’énergie, une hausse de cette consommation de l’ordre de 30% est prévue d’ici 2040. Près de 40% de cette consommation additionnelle pourrait être satisfaite par l’électricité ; ce qui aura un fort impact sur la distribution d’énergie. Pour la société Schneider Electric, spécialiste mondial de la gestion de l’énergie et des automatismes, la distribution d’énergie électrique est principalement assurée par des barres et des fils en cuivre. Ce métal est très largement utilisé pour de nombreux organes de raccordement, appelés objets 2D, qui servent à connecter et déconnecter les appareils. Le principal problème de ces éléments est leur dissipation d’énergie par effet Joule lors du passage du courant électrique. Ce travail de thèse a ainsi consisté à l’élaboration et l’étude d’une nouvelle génération de conducteur électrique et/ou thermique plan (2D) dans l’objectif de palier à ce problème. Pour cela, une nouvelle méthodologie de fabrication de matériaux composites Cu/C 2D a été développée. Elle est composée d’une étape de pré-traitement des poudres, d’une nouvelle technique de mélange et d’une mise en forme du matériau par compression uniaxial à chaud. Différents types de poudres métalliques (cuivre dendritique et cuivre plaquette) et poudres carbonées (graphite, graphène multi-couches, oxyde de graphène) ont été étudiés. L’orientation du renfort au sein de la matrice métallique et l’interface entre ces deux composants ont été optimisées. Cette méthodologie, associée aux caractérisations physico-chimiques des matériaux et à des modèles théoriques, a permis de mieux comprendre les paramètres clés pour l’obtention d’un matériau possédant des propriétés physiques améliorées. Ainsi, les matériaux Cu/C 2D élaborés au cours de cette thèse présentent, suivant le type renfort, une augmentation des propriétés mécaniques (allant de 36% à 120% pour la dureté Vickers), une amélioration de la conductivité thermique (variant de 8% à 56%) et une résistivité électrique cohérente en regard des propriétés du cuivre, matériau de référence. / Since several years, society has become more and more energy-consuming. This increase goes hand in hand with the progress of access to energy, continuous world population growth, the improvement of life quality and the development of new technologies. According to the International Energy Agency, an increase of this consumption of the order of 30 % is planned before 2040. About 40 % of this additional consumption could be satisfied by electricity; what will have a strong impact on the distribution of energy. For the company Schneider Electric, world specialist of the management of energy and automatisms, the distribution of electrical energy is mainly assured by copper bars and wires. This metal is widely used for many connecting organs, called 2D objects, which are used to connect and disconnect devices. The main problem of these elements is their dissipation of energy by Joule effect when passing electric current. Thus, this thesis work consisted in the elaboration and study of a new generation of electrical and/or thermal plane (2D) conductor in the objective to overcome this problem. To this end, a new methodology for manufacturing Cu/2D C composite materials has been developed. It consists of a powders pre-treatment step, a new mixing technique and a shaping of the material by uniaxial hot compression. Various types of metal powders (dendritic copper and copper platelet) and carbonaceous powders (graphite, multi-layer graphene, graphene oxide) were studied. The orientation of reinforcement within the metal matrix and the interface between these two components have been optimized. This methodology, combined with physico-chemical characterizations of materials and theoretical models, provided a better understanding of the key parameters for obtaining a material with improved physical properties. Thus, the Cu/2D C materials developed during this thesis show, depending on the type of reinforcement, an increase in mechanical properties (from 36% to 120% for the Vickers hardness), an improvement in thermal conductivity (from 8% to 56%) and an electrical resistivity consistent with the properties of copper, the reference material.

Pour étendre l'utilisation des composites dans des applications plus variées (applications intelligentes et multifonctionnelles), l'une des barrières est leur faible conductivité électrique et thermique. Dans le cas de composites renforcés par des fibres de carbone, la matrice organique est responsable des propriétés isolantes du composite résultant. L'une des solutions pour améliorer les conductivités des matériaux est l'utilisation des nanocharges conductrices. L'amélioration des propriétés électriques et thermiques des polymères nanochargés est une problématique récurrente dans la littérature. Cependant, étudier les propriétés des composites à fibre de carbone continue et nanochargés est moins abordée. Ce travail porte sur la fabrication et la caractérisation des composites nanochargés par du noir de carbone et des nanotubes de carbone. Tout d'abord, un intérêt particulier a été accordé à la phase délicate de la fabrication. Comme mentionné ci-dessus, la mise en œuvre des composites à renfort continu et matrice nanochargée implique des problèmes liés à l'agglomération et à la dispersion inhomogène des nanocharges dans le composite final. Pour résoudre ces problèmes, le choix de la matrice thermoplastique (Polyamide 6) était judicieux. En fait, la dispersion des nanocharges a été faite par extrusion bi-vis qui est connue comme l'une des voies les plus efficaces de séparation d'agglomérats. De plus, la méthode de fabrication à base de films de Polyamide 6, appelée film stacking, assure une partition homogène dès le début du processus. Des observations MEB ont été effectuées pour localiser les nanoparticules. Ceux-là ont montré que les particules pénétraient dans la zone des fibres. En effet, en atteignant le cœur des torons, les nano-charges ont créé un réseau de connectivité entre les fibres pour le passage de courant. Ceci explique l'amélioration constatée de la conductivité électrique des composites en présence de noir de carbone et des nanotubes de carbone. Ces essais ont été réalisés avec la méthode à 4 points. La conductivité électrique du composite à matrice « pure » est passée de 20S / cm à 80S / cm en ajoutant 8% en poids de noir de carbone et à 15S / cm en ajoutant 18% en poids de la même charge nanométrique. Pour les nanotubes de carbone, avec 2,5% en poids, la conductivité était d'environ 150S / cm. Pour les propriétés thermiques, des tests basés sur l'effet Joule ont été réalisés. L'augmentation de la température a été enregistrée en utilisant une caméra IR. Les résultats obtenus sont en accord avec ceux de la conductivité électrique, montrant une amélioration du comportement thermique en présence de nanocharges. Grâce à ces résultats, l'utilisation de ces composites comme outil de suivi d’endommagement était possible. Par ailleurs, la méthode de variation de la résistance électrique a été effectuée. Les matériaux nanochargés ont montré une meilleure sensibilité aux endommagements. Les résultats ont été comparés aux outils classiques de suivi d’endommagement. A la fin, plusieurs applications « intelligentes » ont été testées telles que : le composite à gradients de propriétés et des matériaux nanochargés cousus. / To extend the use of composites in more varied application (smart applications, multifunctional issues), one of the actual barrier is their poor electrical and thermal conductivities. In the case of carbon fiber reinforced composites, organic matrix are in charge of the insulating properties of the resulting composite. One of the solutions to enhance conductivities of materials is the use of conductive nanofillers. Improving the electrical and thermal properties of nanofilled polymers has been investigated in several studies. However, studiing the properties of continuous carbon fiber nano-filled composites is less approached. This work tends to fabricate and characterize carbon black and carbon nanotubes nano-filled composites. First of all, special interest was given to the delicate phase of manufacturing. As mentioned before, processing continuous fiber reinforced nanofilled polymers implies issues related to nanofillers agglomeration and inhomogeneous dispersion in the final composite. To resolve these problems, the choice of the thermoplastic (Polyamide6) matrix seemed preferable. In fact, the dispersion of nanofillers was made by twin screw extrusion which is known as one of the most effective agglomeration separation ways. Adding to this, the fabrication method based on Polyamide 6 shects called film stacking, ensure a homogeneous partition at the beginning of the process. SEM observations were performed to localize the nano-particles. It showed that particles penetrated on the fiber zone. In fact, by reaching the fiber zone, the nano-fillers created network connectivity between fibers which means an easy pathway for the current. It explains the noticed improvement of the electrical conductivity of the composites by adding carbon black and carbon nanotube. This test was performed with the 4 points electrical circuit. It shows that electrical conductivity of 'neat' matrix composite passed from 20S/cm to 80S/cm by adding 8wt% of carbon black and to 15S/cm by adding 18wt% of the same nano-filler. For carbon nanotubes, with '2.5wt% the conductivity was around 150S/cm. For the thermal properties, tests based on Joule's effect were performed. The rise of temperature was recorded using IR camera. Results obtained are in agreement with the electrical conductivity ones, showing enhancement of the thermal behavior in presence of nanofillers. Thanks to these results, the use of these composites as a damage-monitoring tool was possible. By the way, the electrical resistance change method was performed. Nanofilled materials showed better sensitivity to damage. Results were compared with classical damage monitoring tools. At the end, several 'smart' applications were tested such as graded functionalities composite and stitched nanofilled materials.

<p>U ovom radu pripremljeni su različiti polimerni i keramički nanostrukturni materijali, u cilju ispitivanja uticaja vrste i udela nanopunila (čađ, fuleren, silicijum(IV)oksid, aluminijum(III)oksid i titanijum(IV)oksid) na strukturu, reolo&scaron;ko i toplotno pona&scaron;anje kompozita, dobijenih na osnovu stirena, metilmetakrilata i akrilamida, primenom različitih metoda sinteze. Ispitivan je uticaj prisustva različitog udela nanočestica (1, 3 i 5 %<em> m/m</em>) na kinetiku polimerizacije stirena, i na oblast prelaska u staklasto stanje polistirenskih hibridnih materijala. Sintetisana je i serija nanokompozita polimerizacijom metilmetakrilata u prisustvu čestica (silicijum(IV)oksid, aluminijum (III)oksid i titanijum(IV)oksid) različitih dimenzija i hidrofilnosti, ali istog zapreminskog udela (1 %<em> v/v</em>). Na osnovu primene izotermne diferencijalno skanirajude metode (DSC), razvijen je kinetički model za opisivanje dve razičite reakcije tokom polimerizacije vinilnih monomera (reakciju prvog reda i samoubrzanje), i izračunata je debljina međufaznog sloja polimera na čestici u cilju određivanja njegovog uticaja na temperaturu prelaska u staklasto stanje hibridnih materijala. Za ispitivanje strukture i morfologije polistiren/silicijum(IV)oksid nanokompozita dobijenih metodom isparavanja rastvarača, kori&scaron;dene su infracrvena spektroskopija sa Furijeovom transformacijom (FT-IR) i skanirajuda elektronska mikroskopija (SEM). Radi utvrđivanja uticaja udela hidrofobnog silicijum(IV)oksida (2, 5, 10, 15 i 30 %<em> m/m</em>) na toplotnu postojanost polistirenskih materijala, primenjene su istovremena termogravimetrijska i diferencijalno skanirajuda analiza (TG-DSC). Takođe, određen je uticaj veličine čestice fulerena C60 i submikronske čestice čađi na reolo&scaron;ka svojstva polistirenskih kompozita sintetisanih taloženjem polimera iz rastvora. Ispitivanjem reolo&scaron;kog pona&scaron;anja hibridnih materijala, proučavan je uticaj veličine čestica, molekulske mase polimera i indeksa polidisperznosti na viskoznost polistirenskih kompozita. Na osnovu<em> in-situ</em> reolo&scaron;kih analiza polimerizacije u toku želiranja suspenzije nanočestica aluminijum(III)oksida u vodenom rastvoru monomera metakrilamida i N,N&rsquo;-metilenbisakrilamida, utvrđena je jaka katalitička aktivnost povr&scaron;ine aluminijum(III)oksida na nastajanje slobodnih radikala. Radi nalaženja veze između željenih svojstava keramičkih proizvoda i načina njihovog dobijanja, proučavan je uticaj uslova vođenja polimerizacije na slaganje čestica u dobijenom odlivku i na gustinu krajnjeg sinterovanog proizvoda.</p> / <p>In this work, polymeric and ceramic nanostructured materials were prepared using different methods, in order to investigate the influence of nanofiller content and its type (carbon black, fullerene, silica, alumina and titania) on the structure, rheological and thermal behavior of composites, based on styrene, methylmethacrylate and acrylamide. The effect of particles content (1, 3 and 5 wt. %) on the kinetics of styrene radical polymerization and on the glass transition temperature of polystyrene/silica composites was investigated. A series of polymethylmethacrylate nanocomposites containing 1 vol. % of silica, alumina or titania particles (differing in dimensions and surface properties) was obtained. On the basis of isothermal differential scanning calorimetry (DSC), the kinetic model for describing two reactions during vinyl monomer polymerization (first order and autoacceleration) was developed, and the thickness of interfacial layer formed on nanoparticle surface was determined, in order to investigate its influence on the glass transition temperature of polymethylmethacrylate hybrid materials. The structure and the morphology of polystyrene/silica nanocomposites prepared by solvent evaporation were investigated using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The influence of&nbsp; hydrophobic silica content (2, 5, 10, 15 and 30 wt. %) on polystyrene thermal stability was studied by simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC). The effect of fullerene C60 and submicron carbon black particle size on rheological properties of polystyrene composites prepared by the rapid coprecipitation was determined. Following the rheology of hybrid melts, the influence of filler size, molecular weight and polydispersity of polymer matrix on the viscosity of polystyrene composites was studied. On the basis of in-situ rheology analysis of polymerization process during the gelation of alumina nanoparticles suspension in aqueous solution of methacrylamide and N,N&rsquo;- methylene bisacrylamide monomers, the strong catalytic activity of alumina surface on the free radicals formation was determined. In order to find the correlation between desired properties of ceramic products and their preparation procedure route, the influence of polymerization conditions on the green body structure and sintered body density was studied in details.</p>