Concreto celular polimérico: influência na adição de resíduo de poliéster insaturado termofixo

This work addresses the production of lightweight concrete building elements, such as plates, prefabricated slabs for pre-molded and panels of fencing, presenting a singular concrete: the Lightweight Concrete, with special properties such low density and good strength, by means of the joint use of industrial waste of thermosetting unsaturated polyesters and biodegradable foaming agent, named Polymeric Lightweight Concrete. This study covered various features of the materials used in the composition of the Polymeric Lightweight Concrete, using a planning of factorial design 23, aiming at studying of the strength, production, dosage processes, characterization of mechanical properties and microstructural analysis of the transition zone between the light artificial aggregate and the matrix of cement. The results of the mechanical strength tests were analyzed using a computational statistics tool (Statistica software) to understand the behavior and obtain the ideal quantity of each material used in the formula of the Polymeric Lightweight Concrete. The definition of the ideal formula has the purpose of obtaining a material with the lowest possible dry density and resistance to compression in accordance with NBR 12.646/92 (≥ 2.5 MPa after 28 days). In the microstructural characterization by scanning electron microscopy it was observed an influence of the materials in the process of cement hydration, showing good interaction between the wrinkled face of the residue of unsaturated polyesters thermosetting and putty and, consequently, the final strength. The attaining of an ideal formula, given the Brazilian standards, the experimental results obtained in the characterization and comparison of these results with conventional materials, confirmed that the developed Polymeric Lightweight Concrete is suitable for the production of building elements that are advantageous for construction

Avaliação de inibidores verdes microemulsionados na inibição à corrosão do aço carbono AISI 1020

In general, among the corrosion inhibitors surfactants are the most commonly used compounds, because they are significantly effective by forming protective films on anodic and cathodic areas. In this study, microemulsions containing he biodegradable saponified coconut oil as surfactant (SME-OCS) was used as green corrosion inhibitors. With this purpose, methanolic extracts of Ixora coccinea Linn (IC) and a polar fraction rich in alkaloids (FA) obtained from Croton cajucara Benth solubilized in the SME-OCS system were examined in the presence of AISI 1020 carbon steel, in saline solution (NaCl 3,5 %). The efficiency of corrosion inhibition of IC and FA were evaluated in the following microemulsions: SME-OCS-IC and SME-OCS-FA. The microemulsion system SME-OCS in the presence and absence of IC and FA was assessed by measurements of weight loss and the electrochemical method of polarization resistance, with variation in the concentration of IC and FA (50 - 400 ppm), showing significant results of corrosion inhibition (83,6 % SME-OCS; 92,2 % SME-OCS-FA; and 95,3 % SME-OCS-IC)

Development of Locust Bean Gum Nanoparticles for protein delivery

Dissertação de Mestrado, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2014

Síntese, caracterização e aplicação de LaSBA-15 e como catalisador para obtenção de biodiesel de soja via rota etílica

Biodiesel is an alternative fuel, renewable, biodegradable and nontoxic. The transesterification of vegetable oils or animal fat with alcohol is most common form of production of this fuel. The procedure for production of biodiesel occurs most commonly through the transesterification reaction in which catalysts are used to accelerate and increase their income and may be basic, acid or enzyme. The use of homogeneous catalysis requires specific conditions and purification steps of the reaction products (alkyl ester and glycerol) and removal of the catalyst at the end of the reaction. As an alternative to improve the yield of the transesterification reaction, minimize the cost of production is that many studies are being conducted with the application of heterogeneous catalysis. The use of nano-structured materials as catalysts in the production of biodiesel is a biofuel alternative for a similar to mineral diesel. Although slower, can esterify transesterified triglycerides and free fatty acids and suffer little influence of water, which may be present in the raw material. This study aimed at the synthesis, characterization and application of nano-structured materials as catalysts in the transesterification reaction of soybean oil to produce biodiesel by ethylic route. The type material containing SBA-15 mesoporous lanthanum embedded within rightly Si / La = 50 was used catalyst. Solid samples were characterized by X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, nitrogen adsorption and desorption. For the transesterification process, we used a molar ratio of 20:1 alcohol and oil with 0.250 g of catalyst at 60°C and times of 6 hours of reaction. It was determined the content of ethyl esters by H-NMR analysis and gas chromatography. It was found that the variable of conversion obtained was 80%, showing a good catalytic activity LaSBA-15 in the transesterification of vegetable oils via ethylic route

Compatibilidade de pereiras européias enxertadas sobre marmeleiro 'Adams' e 'EMC'.

O trabalho teve como objetivo avaliar a compatibilidade de enxertia de cultivares de pereiras sobre porta enxertos de marmeleiros 'Adam's e 'EMC'. O experimento foi desenvolvido em viveiro comercial da empresa Frutirol Agrícola Ltda, localizada no município de Vacaria - RS, a 980 m de altitude. Os porta enxertos de marmeleiros 'Adam's e 'EMC' foram enxertados no mês de julho de 2006 com as cultivares copa Danjou, Conference, Packham's Triumph, Abate Fetel e Rocha sobre os dois porta enxertos; Santa Maria, Benita, Foreli e Decana de Comice sobre o marmeleiro 'Adam's e, Clapp's Favourite e William's sobre 'EMC'. Utilizou-se a técnica de enxertia de garfagem dupla fenda, onde se enxertou ramos da cultivar copa com duas gemas sobre os respectivos porta enxertos, os quais apresentavam diâmetro médio de 8 mm. Em seguida foram amarrados com fita biodegradável BUDTAPE. Em julho de 2007 procederam-se as seguintes avaliações: diâmetro da copa e do porta enxerto (distantes 5 cm do ponto de enxertia), medido com auxílio de um paquímetro; altura de plantas (medida a partir do nível do solo até o ápice da planta); área da seção do tronco da copa e do porta enxerto foi obtida através da fórmula A = (? x (D/2)2) Sendo: A = área da seção do ramo (cm3); ? = 3,1416; D = Diâmetro do ramo principal (mm) e os resultados foram expressos em centímetros cúbicos; Os dados foram submetidos à análise de variância e posteriormente à comparação de médias através do teste de Tukey ao nível de 5% de probabilidade de erro. Os resultados demonstram que a cv. Danjou apresenta pouco vigor em relação as demais cvs. estudadas, para ambos os porta enxertos; plantas vigorosas apresentam menor diferença de diâmetro entre porta enxerto e copa; a cv. Conference apresenta-se mais vigorosa em relação às demais cvs. estudadas quando enxertadas sobre 'EMC'; a cv. William's apresenta incompatibilidade com o marmelo 'EMC'.