Fibras de licuri: um reforço vegetal alternativo de compósitos poliméricos

This research is based, at first, on the seeking of alternatives naturals reinforced in place of polymeric composites, also named reinforced plastics. Therein, this work starts with a whole licuri fiber micro structural characterization, as alternative proposal to polymeric composites. Licuri fiber is abundant on the Bahia state flora, native from a palm tree called Syagrus Coronata (Martius) Beccari. After, it was done only licuri fiber laminar composite developing studies, in order to know its behavior when impregnated with thermofix resin. The composite was developed in laminar structure shape (plate with a single layer of reinforcement) and produced industrially. The layer of reinforcement is a fabric-fiber unidirectional of licuri up in a manual loom. Their structure was made of polyester resin ortofitálica (unsaturated) only reinforced with licuri fibers. Fiber characterization studies were based on physical chemistry properties and their constitution. It was made by tension, scanning electron microscopy (SEM), x-ray diffraction (RDX) and thermal analyses (TG and DTA) tests, besides fiber chemistry analyses. Relating their mechanical properties of strength and hardness testing, they were determined through unit axial tension test and flexion in three points. A study in order to know fiber/matrix interface effects, in the final composites results, was required. To better understand the mechanical behavior of the composite, macroscopic and microscopic optical analysis of the fracture was performed

Sorção de petróleo por fibras vegetais

Nowadays, when accidents with oil tanker or shore tanks occur and there is oil spill, some arrangements are made in order to repress and to fix the situation. For the containment, barriers or detours are usually made of synthetic materials such as polyurethane foam. In order to clear water away, techniques like in loco burning, biodegradant agents, dispersant agents and sorbent materials application are used. The most of the sorbent materials are also synthetic and they are used because it is easy to store them and their availability in market. This dissertation introduces the study of vegetable fibers of pineapple leaf fibers (Ananas comosus (L.) Merr.), cotton fibers (Gossypium herbaceum L.), kapok fibers (Ceiba pentandra (L.) Gaertn.), curauá fibers (Ananas erectifolius L.B. Sm.) and sisal fibers (Agave sisalana Perrine) related to their capacity of sorption of oil in case of accidental spill in the ocean. This work evaluates the substitution possibility of synthetic materials by natural biodegradable materials with less cost

Desempenho mecânico de compósitos híbridos de fibras naturais e poliéster não saturado

With the objective to promote sustainable development, the fibres found in nature in abundance, which are biodegradable, of low cost in comparison to synthetic fibres are being used in the manufacture of composites. The mechanical behavior of the curauá and pineapple leaf fibre (PALF) composites in different proportions, 25% x 75% (P1), 50% x 50% (P2) e 75% x 25% (P3) were respectively studied, being initially treated with a 2% aqueous solution of sodium hydroxide. Mechanical analyses indicated that with respect to studies of traction, for the combination of P1 and P3, better results of 22.17 MPa and 16.98 MPa, were obtained respectively, which are higher than that of the combination P2. The results of the same pattern were obtained for analysis of bending resistance where P1 is 1.21% and P3 represents 0.96%. In the case of resistance to bending, best results were obtained for the combination P1 at 49.07 MPa. However, when Young's modulus values were calculated, the values were different to the pattern of the results of other tests, where the combination P2 with the value of 4.06 GPa is greater than the other combinations. This shows that the PALF had a greater influence in relation to curauá fibre. The analysis of the results generally shows that in combinations of two vegetable fibers of cellulosic origin, the fiber which shows higher percentage (75%) is the best option than to the composition of 50%/50%. In the meantime, according to the results obtained in this study, in the case where the application should withstand bending loads, the better composition would be 50%/50%

Desenvolvimento de um laminado compósito híbrido a base de fibras de vidro/licurí

This research work is based, in search of reinforcement s vegetable alternative to polymer composites. The idealization of making a hybrid composite reinforced with vegetable fibers licuri with synthetic fibers is a pioneer in this area. Thus was conceived a hybrid composite laminate consisting of 05 (five) layers being 03 (three) webs of synthetic fibers of glass and E-02 (two) unidirectional fabrics of vegetable fibers licuri. In the configuration of the laminate layers have alternating distribution. The composite laminate was manufactured in Tecniplas Commerce & Industry LTD, in the form of a card through the manufacturing process of hand lay up. Licuri fibers used in making the foil were the City of Mare Island in the state of Bahia. After cooking and the idealization of the hybrid composite laminate, the objective of this research work has focused on evaluating the performance of the mechanical properties (ultimate strength, stiffness and elongation at break) through uniaxial tensile tests and three point bending. Comparative studies of the mechanical properties and as well as among other types of laminated hybrid composites studied previously, were performed. Promising results were found with respect to the mechanical properties of strength and stiffness to the hybridization process idealized here. To complement the entire study were analyzed in terms of macroscopic and microscopic characteristics of the fracture for all tests.

Utilización de compost agotado de champiñón como capa de coberturas en nuevos ciclos de producción

El objetivo de este trabajo fue evaluar el comportamiento agronómico de seis mezclas de cobertura, elaboradas a partir de sustrato postcultivo del champiñón Agaricus bisporus, en nuevos ciclos de cultivo. Los resultados obtenidos mostraron la viabilidad de la reintroducción del sustrato en nuevos ciclos de cultivo, ya sea como material de base único, si se somete a un proceso de lavado para eliminar sales solubles, o bien mezclado con otros materiales de baja conductividad, como es el caso de la turba rubia o la fibra de coco. Se destacan los altos valores de efiCiência biológica registrados, que llegaron hasta los 100 kg kg-1 de compost, similares a los proporcionados por los testigos, y los altos valores relativos observados (con respecto a los testigos) en el contenido en materia seca de los carpóforos cosechados con algunas de las nuevas coberturas elaboradas. Esta reutilización del compost constituye una alternativa interesante, con vistas a reemplazar a las tierras y a los sustratos orgánicos utilizados habitualmente como cobertura, con la doble ventaja de disminuir los costos de elaboración y el impacto ambiental.

Desenvolvimento e análise de material compósito a base de penas de frango (fibras de queratina-KF) e matriz de poliéster insaturado

Use of natural fibres as a reinforcement material in the manufacture of composites show a series of advantages: availability, biodegradability, low weight and regeneration in relation to synthetic fibres, thus justifying its utilization. In the present research work, composites were developed with chicken feathers (KF), using unsaturated polyester resin as matrix, for diversified applications, mainly in the furniture/timber industry.At present, in Brazil the chicken feathers are used as part of the animal feed, even though this material possesses low aggregated value. The chicken feathers are hollow, light and resistant. After washing with water at room temperature, a part of the chicken feathers were treated with 2% NaOH. Composites were manufactured using treated and untreated chicken feathers with unsaturated orthothalic polyester resin and 1% peroxide as catalyser, obtained in the commerce. Samples with size 150x25x3 mm for mechanical tests were cut by laser in the composite plate. Mechanical analyses were carried out in the Laboratório de Metais e Ensaios Mecânicos UFRN. All the analyses were in accordance with ASTM standards. SEM analyses were also carried out on the samples.In the analyses of the results obtained, it was observed that the composites made with untreated chicken feathers showed better results (Traction 11.406 MPa and 9.107 MPa Bending 34.947 and 20.918 MPa for samples with and without treatment respectively) compared to the composite with treated feathers. Very low values of the water absorption results, evidenced the impermeability characteristic of the feathers. From the SEM images, the structure, fracture and the fibre/matrix adsorption can be evidenced. In the flammability test, it was observed that despite the feathers having sulfur as a constituent, natural inhibitor of flame, no burning support of the composites, because the manufacturing process of the composite

Desenvolvimento de têxteis técnicos para reforço de compósitos poliméricos

Materials denominated technical textiles can be defined as structures designed and developed with function to fulfill specific functional requirements of various industrial sectors as are the cases of the automotive and aerospace industries. In this aspect the technical textiles are distinguished from conventional textile materials, in which the aesthetic and of comfort needs are of primordial importance. Based on these considerations, the subject of this dissertation was established having as its main focus the study of development of textile structures from aramid and glass fibers and acting in order to develop the manufacture of composite materials that combine properties of two different structures, manufactured in an identical operation, where each structure contributes to improving the properties of the resulting composite material. Therefore were created in laboratory scale, textile structures with low weight and different composition: aramid (100%), glass (100%) and aramid /glass (65/35%), in order to use them as a reinforcing element in composite materials with polyester matrix. These composites were tested in tension and its fracture surface, evaluated by MEV. Based on the analysis of mechanical properties of the developed composites, the efficiency of the structures prepared as reinforcing element were testified by reason of that the resistance values of the composites are far superior to the polyester matrix. It was also observed that hybridization in tissue structure was efficient, since the best results obtained were for hybrid composites, where strength to the rupture was similar to the steel 1020, reaching values on the order of 340 MPa

Avaliação da estrutura de tecidos técnicos como elemento reforçante em compósitos poliméricos sistema poliéster isoftálico

Materials known as technical textiles can be defined as structures designed and developed to meet specific functional requirements of various industry sectors, which is the case in automotive and aerospace industries, and other specific applications. Therefore, the purpose of this work presents the development and manufacture of polymer composite with isophthalic polyester resin. The reinforcement of the composite structure is a technical textile fabric made from high performance fibers, aramid (Kevlar 49) and glass fiber E. The fabrics are manufactured by the same method, with the aim of improving the tensile strength of the resulting polymer composite material. The fabrics, we developed some low grammage technical textile structures in laboratory scale and differentiated-composition type aramid (100%), hybrid 1 aramid fiber / glass (65/35%) and hybrid 2 aramid fiber / glass (85/15% ) for use as a reinforcing element in composite materials with unsaturated isophthalic polyester matrix. The polymer composites produced were tested in uniaxial tensile fracture surface and it´s evaluated by SEM. The purpose of this work characterize the performance of polymer composites prepared, identifying changes and based on resistance to strain corresponding to the mechanical behavior. The objectives are to verify the capability of using this reinforcement structure, along with the use of high performance fibers and resin in terms of workability and mechanical strength; verify the adherence of the fiber to the matrix and the fracture surface by electron microscopy scanning and determination of tensile strength by tensile test. The results indicate that, in a comparative study to the response of uniaxial tensile test for tensile strength of the composites and the efficiency of the low percentage of reinforcement element, being a technical textile fabric structure that features characteristic of lightness and low weight added in polymer composites

Variação de temperatura e umidade e suas influências nas características físicas e mecânicas dos fios de algodão

Cotton is a hydrofilic textile fiber and, for this reason, it changes its properties according to the environment changes. Moisture and Temperature are the two most important factors that lead a cotton Spinning sector and influence its quality. Those two properties can change the entire Spinning process. Understanding this, moisture and temperature must be kept under control when used during the Spinning process, once the environment is hot and dry, the cotton yarns absorb moisture and lose the minimal consistency. According to this information, this paper was developed testing four types of cotton yarns, one kind of cotton from Brazil and the others from Egypt. The yarns were exposed to different temperatures and moisture in five different tests and in each test, six samples that were examined through physical and mechanical tests: resistance, strength, tenacity, yarn´s hairness, yarn´s evenness and yarn´s twisting. All the analysis were accomplished at Laboratório de Mecânica dos Fluídos and at COATS Corrente S.A., where, it was possible to use the equipments whose were fundamental to develop this paper, such as the STATIMAT ME that measures strength, tenacity, Zweigler G566, that measure hairiness in the yarn, a skein machine and a twisting machine. The analysis revealed alterations in the yarn´s characteristics in a direct way, for example, as moisture and temperature were increased, the yarn´s strength, tenacity and hairness were increased as well. Having the results of all analysis, it is possible to say that a relatively low temperature and a high humidity, cotton yarns have the best performance

Viabilidade de uso de um fogão solar para cocção de alimentos com parábola refletora fabricada em compósito que utiliza fibras de Carnaúba e resina Ortoftálica

Presents a composite formed by orthophthalic resin and fiber loading of carnauba straw. The fibers were first dried in direct sun exposure and subsequently ground into fodder for the reduction in size. Various formulations of the composite were preliminarily tested by choosing the one presenting the best processability in applying the mold. The composite produced is used for the manufacture of a parabolic surface subsequently coated with mirror segments, flexible plastic, for reflecting the solar rays incident on it. The reflective parable represents the main element of the solar cooker that works with the concentration of sunlight and has dimensions of 1.14 m in diameter and area of 1.0 m². Manufacturing processes and assembly of solar cooker concentration produced are presented. The results of tests for cooking and baking various foods, including rice, pasta, beans, cake, cassava, shrimp, beef, breaded demonstrating the competitiveness of solar cooker studied with other stoves already manufactured and tested in Brazil are presented and in the world. It was also demonstrated the feasibility of the proposed composite for Prototypes manufacture of solar and other structures that do not require great efforts resistance

Seletividade de herbicidas em variedades de cana-de-açúcar

Este trabalho teve como objetivo avaliar a seletividade do herbicida topramezone aplicado de forma isolada e em mistura com tebuthiuron, em pós-emergência inicial, sobre dez variedades de cana-de-açúcar em condição de cana-planta. Os tratamentos utilizados foram: topramezone + Dash® (70 g ha-1 + 0,25% v/v); topramezone + tebuthiuron + Dash® (70 + 1.000 g ha-1 + 0,25% v/v); topramezone + tebuthiuron + Dash® (100 + 1.000 g ha-1 + 0,25% v/v); e ametryn + tebuthiuron (1.500 + 1.000 g ha-1), aplicados aos 35 dias após o plantio, além de uma testemunha sem aplicação de herbicidas. Durante a condução do experimento, todas as parcelas permaneceram livres da interferência das plantas daninhas por meio de capinas. As plantas de cana-de-açúcar estavam com duas a quatro folhas por ocasião da aplicação dos herbicidas. O delineamento experimental utilizado foi o de blocos casualizados em parcelas subdivididas, com quatro repetições, sendo as variedades dispostas nas parcelas e os herbicidas nas subparcelas. As variedades utilizadas foram: SP 83 2847, SP 80 3280, RB 85 5453, SP 80 1842, SP 89 1115, RB 86 7515, PO 8862, RB 85 5156, SP 80 1816 e SP 81 3250. As avaliações visuais de fitotoxicidade foram realizadas aos 7, 14, 28 e 35 dias após a aplicação. Ao final do estudo foram determinados os parâmetros tecnológicos pol, fibra e brix e os parâmetros produtivos rendimento de colmos e produção de açúcar. A formulação isolada de topramezone seguida de suas misturas com tebuthiuron proporcionaram inicialmente severos sintomas visuais de injúrias às plantas de cana-de-açúcar; contudo, as plantas de todas as variedades testadas tiveram uma total recuperação visual a partir dos 35 dias após a aplicação dos herbicidas. A mistura de tebuthiuron com topramezone reduziu os sintomas de injúrias iniciais provocados por este último. A mistura de ametryn + tebuthiuron foi o tratamento que evidenciou a ação fitotóxica menos severa às plantas, independentemente da variedade estudada. Nenhum dos herbicidas testados afetou negativamente os componentes tecnológicos e produtivos, sendo as diferenças observadas dependentes apenas das variedades. Podem-se considerar seletivos os herbicidas utilizados sobre as variedades avaliadas de cana-de-açúcar.

Adubação foliar com nitrato de potássio em algodoeiro

Em diversas lavouras de algodão, no Brasil e no exterior, tem ocorrido deficiência tardia de potássio. Com o objetivo de verificar a influência da adubação foliar com nitrato de potássio (KNO3) na nutrição e produção de algodão (Gossypium hirsutum L.), em vista do nível de nutrição potássica, da época de aplicação e dose do produto, em locais com diferentes potenciais de produtividade, foram desenvolvidos experimentos em dois anos agrícolas (2000/2001 e 2001/2002). Foram empregadas doses de 16 e 32 kg ha-1 de KNO3, divididas em duas ou quatro aplicações, a partir da primeira semana de florescimento do algodoeiro. em outro experimento, foi aplicado 32 kg ha-1 de KNO3, em quatro aplicações realizadas da segunda à quinta semana de florescimento. A diminuição dos teores de potássio nas folhas do algodoeiro é um processo normal na fase de senescência da folha em fim de ciclo e não foi revertido com uso suplementar de K. A adubação foliar com KNO3 pode, em algumas condições, como por exemplo, em plantas deficientes em potássio, aumentar o teor do nutriente na folha. Entretanto, isso não afeta o conteúdo do nutriente nos frutos, a produtividade e a qualidade da fibra.

Physiochemical analysis and centesimal composition of Pleurotus ostreatus mushroom grown in residues from the Amazon

O presente estudo teve como objetivo avaliar a composição nutricional dos cogumelos produzidos em substratos alternativos à base de resíduos agrícolas e agroindustriais da Amazônia. Determinou-se C, N, pH, umidade, sólidos solúveis, proteína, lipídios, fibra total, cinzas, carboidratos e energia. Os substratos foram formulados a partir de serragem de Simarouba amara Aubl. (marupá), Ochroma piramidale Cav. ex. Lam. (pau de balsa) e do estipe de Bactris gasipaes Kunth (pupunheira) e de Saccharum officinarum (cana-de-açúcar). Os resultados demonstraram que: a composição nutricional do P. ostreatus variou com o substrato de cultivo e; O P. ostreatus pode ser considerado um importante alimento devido suas características nutricionais: altos teores de proteínas, carboidratos metabolizáveis e fibras; baixos teores de lipídios e de calorias.

Produção de mudas de abóbora com diferentes doses de nitrogênio e potássio

O experimento foi desenvolvido em ambiente protegido, em São Manuel (SP). O objetivo deste trabalho foi avaliar a produção de mudas de abóbora 'Menina Brasileira' em substrato à base de fibra de coco com diferentes doses de nitrogênio e potássio em fertirrigação. Utilizou-se o delineamento experimental em blocos ao acaso, com 16 tratamentos em esquema fatorial 4 x 4, sendo quatro doses de nitrogênio (0, 40, 80 e 120 mg L-1 de N) na forma de nitrato de amônio e quatro doses de potássio (0, 70, 140 e 210 mg L-1 de K2O ) na forma de cloreto de potássio, em quatro repetições e dez plantas por parcela. As características avaliadas foram: massa fresca e seca da parte aérea e raiz, altura e número de folhas. As doses de potássio não influenciaram as características avaliadas. Houve, porém, aumento linear para a maioria das características avaliadas com doses crescentes de nitrogênio, exceto para a massa seca da raiz.

Análise técnica e econômica do processo de obtenção de espaguetes com adição de farinha de trigo integral e farinha de linhaça

This work studies the fabrication of spaghetti through the process at high temperatures through the use of flour added to flour and flaxseed meal, with the aim of evaluating the final product quality and estimate the cost of production. The values of moisture, ash, protein, wet gluten, gluten index, falling number and grain of flour and mixtures to test to be the possible use in mass manufacturing and technological criteria for compliance with current legislation. Spaghetti noodles type were manufactured by adding 10% and 20% flour and 10% and 20% flaxseed meal with performance of physical-chemical, sensory and rheological properties of the products. Further analysis was performed on the product acceptance and estimation of production cost in order to create subsidies to enable the introduction of products with greater acceptance and economic viability in the market by the food industry. On the rheology of the product test was cooking the pasta, specifying the volume increase, cooking time and percentage of solid waste. In the sensory evaluation was carried out the triangular test of product differentiation with 50 trained judges and acceptance testing by a hedonic scale with evaluation of the aspects color, taste, smell and texture. In defining the sensory profile of the product was performed with ADQ 9 judges recruited and trained at the factory, using unstructured scale of 9 cm, assessing the attributes of flavor of wheat, flax flavor, consistency, texture of raw pasta, raw pasta color and color of cooked pasta. The greater acceptance of product quality was good and the pasta with 20% flour, 10% followed by the full product, 10% and 20% flaxseed characterized the average quality of the criterion of loss analysis of solids, together with mass full commercial testing. In assessing the estimated cost of production, the two products more technologically feasible and acceptable (20% whole and 10% flaxseed) were evaluated in high temperature processes. With total cost of R $ 4,872.5 / 1,000 kg and R $ 5,354.9 / 1,000 kg respectively, the difference was related to the addition of lower inputs and higher added value in the market, flour and flaxseed meal. The comparative analysis of cases was confirmed the reduction in production time (10h), more uniform product to the drying process at high temperature compared to conventional