Produção de lipídios microbianos a partir de glicerol bruto gerado na síntese de biodiesel

Diante da grande quantidade de glicerol bruto gerado na síntese do biodiesel e seu baixo valor comercial, torna-se fundamental encontrar formas alternativas para converter este substrato em produtos com valor agregado. Neste contexto, este trabalho teve como objetivo avaliar diferentes leveduras oleaginosas capazes de metabolizar o glicerol bruto, gerado como coproduto na síntese de biodiesel, visando produzir biomassa como fonte de lipídios. Todos os cultivos foram realizados em frascos agitados, em condições estabelecidas de acordo com cada etapa do trabalho, sendo obtidos dados relativos ao crescimento celular e à produção de lipídios, tratados estatisticamente conforme o propósito. Lipomyces lipofer NRRL Y-1155 apresentou diferenças significativas em relação às outras leveduras oriundas de banco de cultura, atingindo 57,64% de lipídios na biomassa. Estas leveduras apresentarem perfis de ácidos graxos diferenciados, semelhantes aos dos principais óleos vegetais utilizadas na síntese de biodiesel, com predominância de ácidos graxos poli-insaturados, especialmente ácido linoleico (68,3% na levedura Rhodotorula glutinis NRRL YB-252). O ácido gama-linolênico, um ácido graxo essencial ω6, foi detectado em todas as leveduras analisadas, sendo que na biomassa de Candida cylindracea NRRL Y-17506 chegou a 23,1%. Através de um planejamento experimental Plackett-Burman, verificou-se que as variáveis concentração de extrato de levedura e de MgSO4.7H20 demonstraram maior influência na produção de lipídios por uma linhagem silvestre de Rhodotorula mucilaginosa. Para esta levedura, a partir da análise de efeitos foi possível estabelecer a seguinte condição para a produção de lipídios: 30,0 g.L-1 glicerol; 5,0 g.L-1 KH2PO4; 1,0 g.L-1 Na2HPO4; 3,0 g.L-1 MgSO4.7H2O; 1,2 g.L-1 extrato de levedura; pH inicial 4,5; temperatura 25°C. Nestas condições conseguiu-se um teor de lipídios de 59,96% e lipídios totais produzidos de 5,51 g.L-1 . Também foi possível observar aumento no teor de lipídios da biomassa ao longo do tempo de cultivo, bem como o aumento do teor relativo do ácido linoleico, que atingiu 52%. Dentre as leveduras isoladas a partir de amostras ambientais do Extremo Sul do Brasil, a levedura identificada como Cryptococcus humicola se destacou das demais, apresentando proporção de 23,5% de ácidos graxos saturados, 14,8% de ácidos graxos monoinsaturados e 54,9% de ácidos graxos poli-insaturados, destacando-se o ácido linoleico. O planejamento Plackett-Burman foi também utilizado para esta levedura, sendo que as variáveis concentração de extrato de levedura e glicerol bruto demonstraram maior influência na produção de lipídios. Posteriormente, um delineamento composto central rotacional (DCCR) foi proposto visando à otimização da produção de lipídios. Os modelos empíricos preditivos obtidos para biomassa máxima e lipídios totais permitiram estabelecer para a produção de lipídios por Cryptococcus humicola a seguinte condição otimizada: 100,0 g.L-1 glicerol; 5,0 g.L-1 KH2PO4; 1,0 g.L-1 Na2HPO4; 4,8 g.L-1 extrato de levedura; pH inicial 4,5; temperatura 25°C. Esta condição representou um incremento de cerca de 2 vezes nos lipídios totais em relação à melhor condição estabelecida pelo planejamento Plackett-Burmann e um acréscimo de cerca de 4,8 vezes em relação às condições testadas inicialmente, atingindo 37,61% de lipídios e 8,85 g.L-1 de lipídios totais. Deste modo, os propósitos de valorização de um coproduto oriundo da síntese de biodiesel, bem como a produção de um óleo com potencial para a produção de biodiesel, foram cumpridos.

Estudo experimental do escoamento bifásico líquido gás em golfadas com leve mudança de direção

Gas-liquid two-phase flow is very common in industrial applications, especially in the oil and gas, chemical, and nuclear industries. As operating conditions change such as the flow rates of the phases, the pipe diameter and physical properties of the fluids, different configurations called flow patterns take place. In the case of oil production, the most frequent pattern found is slug flow, in which continuous liquid plugs (liquid slugs) and gas-dominated regions (elongated bubbles) alternate. Offshore scenarios where the pipe lies onto the seabed with slight changes of direction are extremely common. With those scenarios and issues in mind, this work presents an experimental study of two-phase gas-liquid slug flows in a duct with a slight change of direction, represented by a horizontal section followed by a downward sloping pipe stretch. The experiments were carried out at NUEM (Núcleo de Escoamentos Multifásicos UTFPR). The flow initiated and developed under controlled conditions and their characteristic parameters were measured with resistive sensors installed at four pipe sections. Two high-speed cameras were also used. With the measured results, it was evaluated the influence of a slight direction change on the slug flow structures and on the transition between slug flow and stratified flow in the downward section.

Concentration of human pollution tracers with ionic liquids

The main objective of the present thesis consists on the development of an analytical preconcentration technology for the concomitant extraction and concentration of human pollution tracers from wastewater streams. Due to the outstanding tunable properties of ionic liquids (ILs), aqueous biphasic systems (ABS) composed of ILs can provide higher and more selective extraction efficiencies for a wide range of compounds, being thus a promising alternative to the volatile and hazardous organic solvents (VOCs) typically used. For that purpose, IL-based ABS were employed and adequately characterized as an one-step extraction and concentration technique. The applicability of IL-based ABS was verified by their potential to completely extract and concentrate two representative pharmaceutical pollution tracers, namely caffeine (CAF) and carbamazepine (CBZ), from wastewaters. The low concentration of these persistent pollutants (usually found in μg·dm-3 and ng·dm-3 levels, respectively) by conventional analytical equipment does not permit a proper detection and quantification without a previous concentration step. Preconcentration methods commonly applied are costly, timeconsuming, with irregular recoveries and make use of VOCs. In this work, the ABS composed of the IL tetrabutylammonium chloride ([N4444]Cl) and the salt potassium citrate (K3[C6H5O7]) was investigated while demonstrating to be able to completely extract and concentrate CAF and CBZ, in a single-step, overcoming thus the detection limit of the applied analytical equipment. Finally, the hydrotropic effect responsible for the ability of IL-based ABS to extract and concentrate a wide variety of compounds was also investigated. It was shown that the IL rules the hydrotropic mechanism in the solubility of CAF in aqueous solutions, with an increase in solubility up to 4-fold. Moreover, the proper selection of the IL enables the design of the system that leads to a more enhanced solubility of a given solute in the IL-rich phase, while allowing a better extraction and concentration. IL-based ABS are a promising and more versatile technique, and are straightforwardly envisaged as selective extraction and concentration routes of target micropollutants from wastewater matrices.

Isolamento, seleção e cultivo de leveduras com potencia biotecnológico para a produção de endo-xilaneses

Xilanases são enzimas que catalisam a hidrólise das xilanas e têm sido em grande parte, obtidas a partir de bolores e bactérias. No entanto poucos estudos têm sido relatados sobre a produção destas enzimas por leveduras. O presente trabalho teve como objetivo isolar leveduras de diferentes fontes vegetais visando à produção de xilanases, além de maximizar sua produção, estudar o uso de diferentes fontes de nitrogênio e cultivar as leveduras em meios contendo coprodutos agroindustriais. As amostras de alimentos e resíduos foram enriquecidas em caldo extrato de malte e levedura e isoladas em Ágar Nutriente Wallerstein, as leveduras isoladas foram, a seguir, avaliadas quanto à capacidade de degradar xilana presente no meio e produzir halos de hidrólise, os quais foram visualizados através do uso do corante vermelho congo. Os micro-organismos selecionados como potenciais produtores de xilanase foram crescidos em meio complexo líquido e as atividades enzimáticas de endoxilanase, β-xilosidase, carboximetilcelulase, celulase total, pH e concentração de biomassa foram avaliadas ao longo de 96 h de cultivo. Dentre as leveduras isoladas, sete foram selecionadas, e a 18Y foi a que apresentou a maior atividade de endo- xilanase (2,7 U.mL-1 ), sendo esta isolada de chicória e identificada como Cryptococcus laurentii. Esta estirpe apresentou capacidade de produzir xilanase com baixos níveis de celulase, sendo assim selecionada neste trabalho. A maximização de endo-xilanase foi avaliada fazendo uso de planejamento experimental onde primeiramente foi realizado um planejamento fracionário 2 6-2 para verificar os efeitos do pH inicial e as concentrações de xilana, peptona, (NH4)2SO4, extrato de levedura e KH2PO4 sobre a atividade enzimática. Após selecionar as variáveis xilana, peptona, pH e extrato de levedura foi realizado um delineamento composto central rotacional (24 ) onde todos os cultivos foram mantidos a 30°C, 150 rpm durante 96 h sendo retiradas alíquotas para determinação das atividades, pH e biomassa. A produção máxima foi de 6,9 U.mL-1 usando 10,0 g.L-1 de extrato de levedura, 10,0 g.L-1 de peptona, 10,0 g.L-1 de xilana, 1,0 g.L-1 de (NH4)2SO4 em pH 6,5 o que permitiu um incremento de mais de 250% sobre a atividade. Posteriormente foram realizados ensaios avaliando diferentes fontes e concentrações de nitrogênio orgânico e inorgânico. A presença de NH4NO3 e (NH₄)₂SO₄ usados na concentração de 3% proporcionaram as maiores atividades de endo-xilanase (6,2 e 6,0 U.mL-1 respectivamente). O sulfato de amônio foi selecionado e fixado em 1 g.L-1 e logo após um planejamento completo 22 foi realizado onde as variáveis xilana e extrato de levedura foram estudadas e as demais fixadas. As condições ótimas estabelecidas para a produção da enzima foram: concentração de xilana de 18,6 g.L-1 , concentração de extrato de levedura de 10 g.L-1 atingindo 14 U.mL-1 . Após a maximização enzimática estudou-se o crescimento de Pichia pastoris NRRL Y-1603 e Cryptococcus laurentti em cinco substratos agroindustriais visando a possibilidade estes substratos substituírem a xilana em cultivos para a produção de endo-xilanase. Os ensaios foram realizados utilizando os subtratos pré-tratados com NaOH 4% e não tratados. Para inserção dos mesmos aos meios de cultivo, estes foram moídos e adicionados na concentração de 2%. O pré-tratamento para todos as fontes de hemicelulose foi eficiente e promoveu aumento nas atividades produzidas. Cryptococcus laurentti apresentou maior atividade enzimática (8,7 U.mL-1 ) em farelo de arroz desengordurado e pré- tratado enquanto que a levedura Pichia pastoris NRRL Y-1603 apresentou sua melhor condição para produção de endo-xilanase quando cultivada em meio contendo casca de aveia e o farelo de arroz pré-tratados, alcançando atividades máximas de 7,6 e 7,5 U.mL-1 .

Caracterização termo-mecânica de interconectores metálicos recobertos com filmes de LaCrO3

The cells unitaria of the solid oxide fuel cell are separated by means of interconnects, which serve as electrical contact between the cells. Lanthanum Chromite (LaCrO3) has been the most common material used as interconnect in solid oxide fuel cells. Reducing the operating temperature around 800 º C of cells to solid oxide fuel make possibilite the use of metallic interconnects as an alternative to ceramic LaCrO3. Metallic interconnects have advantages over ceramic interconnects such as high thermal conductivity, electricity, good ductility, low cost, good physical and mechanical properties. In this work evaluate the thermo-mechanical properties of the metallic substrate and coated metallic substrate with the ceramic LaCrO3 film via spray-pyrolysis, in order to demonstrate the feasibility of using this material as a component of a fuel cell solid oxide. The materials were characterized by X-ray diffraction, oxidation behavior, mechanical strength, optical microscopy (OM) and scanning electron microscopy (SEM). The X-ray diffraction proved the formation phase of the LaCrO3 on the metallic substrate and the identification of the phases formed after the oxidative test and mechanical strength at high temperature. The oxidation behavior showed the increased oxidation resistance of the coated metallic substrate. It was noted that the mechanical resistance to bending of the coated metallic substrate only increases at room temperature. The optical microscopy (OM) has provided an assessment of both the metallic substrate and the LaCrO3 film deposited on the metal substrate that, in comparison with the micrographs obtained from SEM. The SEM one proved the formation of Cr2O3 layer on the metallic substrate and stability of LaCrO3 film after oxidative test, it can also observe the displacement of the ceramic LaCrO3 film after of mechanical testing and mapping of the main elements as chromium, manganese, oxygen, lanthanum in samples after the thermo-mechanical tests.

Avaliação da influência do nacl em pastas de cimento portland para cimentação de poços de petróleo em zonas evaporíticas

One of the major current challenges for oilwell companies is the extraction of oil from evaporitic zones, also known as pre-salt basins. Deep reservoirs are found under thick salt layers formed from the evaporation of sea water. Salt layers seal the flow of oil from underneath rock formations, which store hydrocarbons and increase the probability of success in oil and gas exploration. Oilwells are cemented using Portland-based slurries to promote mechanical stability and zonal isolation. For pre-salt oilwells, NaCl must be added to saturate the cement slurries, however, the presence of salt in the composition of slurries affects their overall behavior. Therefore, the objective of the present study was to evaluate the effect of the addition of 5 to 25% NaCl on selected properties of Portland-based slurries. A series of tests were carried out to assess the rheological behavior, thickening time, free water and ultrassonic compressive strength. In addition, the slurries were also characterized by thermal analysis, X ray diffraction and scanning electron microscopy. The results showed that the addition of NaCl affected the thickening time of the slurries. NaCl contents up to 10% shortened the thickening time of the slurries. On the other hand, concentrations in excess of 20% not only extended the thickening time, but also reduced the strength of hardened slurries. The addition of NaCl resulted in the formation of a different crystalline phase called Friedel´s salt, where free chlorine is bonded to tricalcium aluminate

Estudo e desenvolvimento de um capacitor eletrolítico de nióbio

It seeks to find an alternative to the current tantalum electrolytic capacitors in the market due to its high cost. Niobium is a potential substitute, since both belong to the same group of the periodic table and because of this have many similar physical and chemical properties. Niobium has several technologically important applications, and Brazil has the largest reserves, around 96%. There are including niobium in reserves of tantalite and columbite in Rio Grande do Norte. These electrolytic capacitors have high capacitance specifies, ie they can store high energy in small volumes compared to other types of capacitors. This is the main attraction of this type of capacitor because is growing demand in the production of capacitors with capacitance specifies increasingly high, this because of the miniaturization of various devices such as GPS devices, televisions, computers, phones and many others. The production route of the capacitor was made by powder metallurgy. The initial niobium powder supplied by EEL-USP was first characterized by XRD, SEM, XRF and laser particle size, to then be sieved into three particle size, 200, 400 e 635mesh. The powders were then compacted and sintered at 1350, 1450 and 1550°C using two sintering time 30 and 60min. Sintering is one of the most important parts of the process as it affects properties as porosity and surface cleaning of the samples, which greatly affected the quality of the capacitor. The sintered samples then underwent a process of anodic oxidation, which created a thin film of niobium pentóxido over the whole porous surface of the sample, this film is the dielectric capacitor. The oxidation process variables influence the performance of the film and therefore the capacitor. The samples were characterized by electrical measurements of capacitance, loss factor, ESR, relative density, porosity and surface area. After the characterizations was made an annealing in air ate 260ºC for 60min. After this treatment were made again the electrical measurements. The particle size of powders and sintering affected the porosity and in turn the specific area of the samples. The larger de area of the capacitor, greater is the capacitance. The powder showed the highest capacitance was with the smallest particle size. Higher temperatures and times of sintering caused samples with smaller surface area, but on the other hand the cleaning surface impurities was higher for this cases. So a balance must be made between the gain that is achieved with the cleaning of impurities and the loss with the decreased in specific area. The best results were obtained for the temperature of 1450ºC/60min. The influence of annealing on the loss factor and ESR did not follow a well-defined pattern, because their values increased in some cases and decreased in others. The most interesting results due to heat treatment were with respect to capacitance, which showed an increase for all samples after treatment

Síntese e caracterização de óxidos de cério e cobalto obtidos por gel-combustão e Pechini aplicados às reações de oxidação de n-hexano

Oxide type spinel AB2O4 presents structure adjusted for application in the automobile industry. The spinel of cobalt has many practical applications had its excellent physical and chemical properties such as catalyst in hydrocarbon oxidation reaction. The CeO2 has been used in many of these processes because it assigns to a material with excellent thermal resistance and mechanics, high capacity of oxygen stockage (OSC) among others properties. This work deals with the synthesis, characterization and catalytic application of spinel of cobalt and CeO2 with fluorita structure, obtained for method of Pechini and method of Gel-Combustion. The process of Pechini, the puff was obtained at 300 ºC for 2 h in air. In the process of Gel-Combustion the approximately at 350 ºC material was prepared and burnt for Pyrolysis, both had been calcined at 500 ºC, 700 ºC, 900 ºC and 1050 ºC for 2 h in air. The materials of the calcinations had been characterized by TG/DTA, electronic microscopy of sweepings (MEV), spectroscopy of absorption in the infra-red ray (FTIR) and diffraction of X-rays (DRX). The obtained material reaches the phase oxide at 450 oC for Pechini method and 500 °C for combustion method. The samples were submitted catalytic reaction of n-hexane on superficies of materials. The reactor function in molar ration of 0, 85 mol.h-1.g-1 and temperature of system was 450 °C. The sample obtained for Pechini and support in alumine of superficial area of 178,63 m2.g-1 calcined at 700 ºC, give results of catalytic conversions of 39 % and the sample obtained for method of gel-combustion and support in alumina of 150 mesh calcined at 500 ºC result 13 % of conversion. Both method were selective specie C1

Método GMP-RAM para avaliação dos riscos ambientais: estudo de caso das nanotecnologias.

A Nanotecnologia está baseada na crescente capacidade da tecnologia moderna de manipular átomos e partículas na nanoescala com o objetivo de criar novos materiais e desenvolver novos produtos e processos. Ela promete grandes avanços nas mais diversas áreas de atuação, desde a Medicina à Engenharia de Materiais. Apesar das nanotecnologias apresentarem propriedades físicas diferentes dos seus correspondente convencionais, ainda não existem metodologias que permitam a avaliação dos riscos associados ao seu emprego e liberação no meio ambiente. Neste cenário, o presente trabalho propõe o emprego e adequação de uma Metodologia comumente empregada para a Avaliação de Risco de Transgênicos para o caso das Nanotecnologias.

Desenvolvimento de bloco de vedação com barita na composição de partida para blindagem de radiação X

This work main objective is to study the use of bricks in barium X-rays rooms in order to contribute to the optimization of shielding rooms diagnosis. The work was based on experimental measurements of X-ray attenuation (40 to 150 kV), using ceramic seal bearing the incorporation of barium sulfat (BaSO4). Different formulations were studied in three different firing temperatures and evaluated for incorporation in the ceramic body. The composition of 20% of barite processed at a temperature of 950 ° C showed better physical and mechanical properties, is considered the most suitable for the purpose of this work. Were produced bricks sealing composition formulated based on that presented the best technological features. These blocks were tested physically as a building material and wall protective barrier. Properties such as visual, deviation from the square, face flatness, water absorption and compressive strength were evaluated for all the blocks produced. The behavior of this material as attenuator for X-rays was investigated by experimental results which take into account mortar manufacturers barium through the different strains and compared with the reference material (Pb). The simulation results indicated that the ceramic block barium shows excellent properties of attenuation equivalence lead taking into account the energy used in diagnostic X-ray

Estudo da incorporação da cal em composições binárias de solo-cimento para produção de tijolos maciços

The use of binders in the soil for the production of solid bricks is an old construction technique that has been used by several civilizations over time. At the same time, the need for environmental preservation and the tendency of scarcity of natural resources make the construction invest in researching new concepts, methods and materials for building systems for the sustainability of their economic activities. Thus arises the need to obtain building materials with low power consumption, capable of reducing the growing housing shortage of rural and urban population. Currently, research has been conducted on this topic to better understand the cementitious and pozzolanic reactions that occur in the formation of the microstructure of the soil-cement when added to other materials such as, for example, lime, and the relationship between microstructure and formed interfaces with the physical, mechanical and chemical analysis in compounds made from these ternary compositions. In this context, this study aimed to analyze the results of the influence of the incorporation of lime to the soil-cement to form a ternary mixture to produce soil-cement bricks and mortar without structural purposes. From the inclusion of contents of 6 %, 8 %, 10% and 12% lime to the soil, and soil-cement mixes in amounts of 2 %, 3 %, 4 % and 5 % were shaped-bodies of -cylindrical specimens to determine the optimum moisture content and maximum dry apparent specific weight. Then they were cured, and subjected to the tests of compressive strength, absorption and durability modified. Compositions obtained the best results in the tests performed on the bodies-of-proof cylindrical served as a parameter for molding of solid bricks, which underwent the same experimental methodology previously cited. The raw materials used, as well as compositions in which the bricks were molded solid, were characterized by physical and chemical tests, X-ray diffraction and scanning electron microscopy. The results obtained in the study indicate that the compositions studied, that showed the best results in terms of compressive strength, water absorption and durability ternary composition was soil, 10 % cement and 2 % lime

Simulador radiográfico antropomórfico de mama humana

Mammography is a diagnostic imaging method in which interpretation depends on knowledge of radiological aspects as well as the clinical exam and pathophysiology of breast diseases. In this work a mammography phantom was developed to be used for training in the operation of mammographic x-ray equipment, image quality evaluation, self-examination and clinical examination of palpation. Polyurethane was used for the production of the phantoms for its physical and chemical properties and because it is one of the components normally used in prostheses. According to the range of flexibility of the polyurethane, it was possible to simulate breasts with higher or lower amount of adipose tissue. Pathologies such as areolar necrosis and tissue rejection due to surgery reconstruction after partial mastectomy were also simulated. Calcifications and nodules were simulated using the following materials: polyethylene, poly (methyl methacrylate), polyamide, polyurethane and poly (dimethyl silicone). Among these, polyethylene was able to simulate characteristics of calcification as well as breast nodules. The results from mammographic techniques used in this paper for the evaluation of the phantoms are in agreement with data found in the literature. The image analyses of four phantoms indicated significant similarities with the human skin texture and the female breast parenchyma. It was possible to detect in the radiographic images produced regions of high and low radiographic optical density, which are characteristic of breasts with regions of different amount of adipose tissue. The stiffnesses of breast phantoms were adjusted according to the formulation of the polyurethane which enabled the production of phantoms with distinct radiographic features and texture similar to human female breast parenchyma. Clinical palpation exam of the phantoms developed in this work indicated characteristics similar to human breast in skin texture, areolar region and parenchyma

Efeito das variáveis laboratoriais protéticas na adesão da porcelana com ligas de níquel-cromo

The metalceramic crowns are usually used in dentistry because they provide a resistant structure due to its metallic base and its aesthetics from the porcelain that recovers this structure. To manufacture these crowns, a series of stages should be accomplished in the prosthetic laboratories, and many variables can influence its success. Changes in these variables cause alterations in the metallic alloy and in the porcelain, so, as consequence, in the adhesion between them. The composition of the metal alloy can be modified by recasting alloys, a common practice in some prosthetic laboratories. The aim of this paper is to make a systematic study investigating metalceramic crowns as well as analyzing the effect of recasting Ni-Cr alloys. Another variable which can influence the mechanism of metalceramic union is the temperature used in firing porcelain procedure. Each porcelain has to be fired in a fixed temperature which is determined by the manufacturer and its change can cause serious damages. This research simulate situations that may occur on laboratory procedures and observe their consequences in the quality of the metalceramic union. A scanning eletron microscopy and an optic microscopy were accomplish to analyse the metal-ceramic interface. No differences have been found when remelting alloys were used. The microhardness were similar in Ni-Cr alloys casted once, twice and three times. A wettability test was accomplished using a software developed at the Laboratório de Processamento de Materiais por Plasma, on the Universidade Federal do Rio Grande do Norte. No differences were found in the contact angle between the solid surface (metallic substratum) and the tangencial plane to the liquid surface (opaque). To analyse if the temperature of porcelain firing procedure could influence the contact area between metal and porcelain, a variation in its final temperature was achieve from 980° to 955°C. Once more, no differences have been found

Desenvolvimento e otimização de snacks saudáveis à base de iogurte

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia - UL

Conservação e restauro de azulejo: metodologias de intervenção vs indicadores de compatibilidade

A escassez de parâmetros técnicos e científicos e o caráter subjetivo que em regra preside à escolha de determinado material, produto ou técnica suscitaram o interesse pelo presente tema onde se procurou aumentar as ferramentas de análise e de apoio à decisão em intervenções de conservação do património azulejar. Procurou compreender-se o azulejo a nível histórico, estético, técnico e material, estudando-o do ponto de vista físico, químico e mineralógico. Comparando o azulejo com as réplicas produzidas para intervenções de conservação e restauro estudadas, concluiu-se que as suas composições, química e mineralógica, são diferentes, embora não se verifiquem tantas dissemelhanças ao nível das propriedades físicas. As linhas orientadoras da conservação e restauro de azulejo foram lançadas por Santos Simões a partir dos anos 40 do séc. XX e, desde então, foi-se desenvolvendo um pouco à margem das restantes áreas de especialidade, mesmo ao nível do ensino. Os resultados do inquérito internacional junto dos profissionais que trabalham em conservação e restauro de azulejo in situ corroboram de certo modo este facto e, simultaneamente, permitem uma apreensão da situação atual. Constatou-se uma quase total ausência de documentação sobre intervenções realizadas, mas a análise de casos de estudo e de relatórios permitiu uma primeira sistematização da informação disponível segundo os materiais correntemente utilizados. Procedeu-se a uma identificação e tipificação de patologias decorrentes das intervenções procurando entender qual o papel que tiveram os materiais utilizados e as técnicas de intervenção no desempenho das intervenções. Os processos de reintegração volumétrica e cromática mereceram uma maior atenção, procedendo-se à simulação de todo o sistema, em contexto laboratorial, com base nos materiais correntemente utilizados. Os resultados revelam comportamento diferenciado dos materiais de origem orgânica e inorgânica, evidenciando estes últimos uma maior compatibilidade com o azulejo, mas um pior desempenho a médio/longo prazo. O reconhecimento das soluções mais ou menos compatíveis permitiu delinear uma metodologia de avaliação da compatibilidade, da eficácia e do desempenho dos materiais e das técnicas utilizadas, contribuindo também para a definição de algumas recomendações e de critérios de atuação; Abstract The lack of information found, when selecting a material, product or technique, to apply on a specific conservation treatment contributed to the interest on this topic. The historical, aesthetic and technical characteristics of the azulejo was researched by studying their physical, chemical and mineralogical properties. Comparing original azulejos with the replicas produced for conservation treatments studied, it was concluded that the chemical and mineralogical composition is different, although there are less dissimilarities in terms of physical properties. The guidelines for conservation and restoration were launched by Santos Simões in the 40s and since then, it has been developing a bit on the sidelines of the remaining areas of expertise, even at an educational level. The results of an international survey, near professionals working in conservation and restoration of azulejo in situ, corroborate this fact and simultaneously allow an insight of the current situation. It was found an almost complete lack of technical documentation about previous conservation interventions, but the analysis of existent case studies and intervention reports permitted a systematization of the available information, also considering the materials commonly used. The identification and characterization of damages resulting from interventions, was performed trying to establish a correlation with the materials used and intervention techniques. The attention focused on the study of the infills and chromatic reintegration and a simulation of the entire system was developed, in a laboratory context, on the basis of commonly used materials. The results reveal a distinct behavior between the organic and inorganic materials, showing the latter greater compatibility with the azulejos but a worse medium/long-term performance. The recognition of more or less compatible solutions allowed to outline a methodology to evaluate the compatibility, efficiency and performance of materials and techniques used, also contributing to define some recommendations and action criteria.