Tall oil e seus subprodutos: alternativas como preservantes para madeira

Pós-graduação em Engenharia Mecânica - FEG

Viabilidade e longevidade de sementes de tabebuia aurea benth. & hook. submetidas a diferentes métodos de armazenamento

Seeds Tabebuia aurea (syn. Handroanthus aureus Mattos), The seeds of Tabebuia aurea (syn. Handroanthus Mattos aureus), have low metabolic rates, which favors their storage conditions and freezing temperatures when stored at room temperature, there is a progressive decline in viability. Therefore, this study aims to determine the viability and longevity of seeds of Tabebuia aurea subjected to different storage methods. There were used 6100 seeds. In 2400 seeds were stored refrigerator, which in 1200 placed in transparent plastic bag and 1200 in Kraft paper bags. 3600 Other seeds were placed in room temperature and 1200 seeds in clear plastic bag, 1200 in Kraft paper bags and tray open in 1200. For each treatment, four replicates of 25 seeds for 12 months, with design was completely randomized. The average germination, normal seedlings and speed germination index were transformed into (x+1)(-1/2). The data were submitted to ANOVA and means compared by Tukey test at 5%. Also regressions polynomials were modeled for the variables study in function of the periods of storage of the seeds. The seeds stored in the refrigerator at 13 C maintained a high germination rate and normal seedling germination rate during the 360 days of evaluation. The method suitable for the seed storage of Tabebuia aurea is in the refrigerator at 13 degrees C, both in plastic and paper.

Some Physical and Mechanical Properties of Medium-Density Fiberboard Made from Giant Bamboo

The objective of this study was to evaluate the density, density profile, water swelling and absorption, modulus of elasticity and rupture from static bending, and tensile strength of experimental medium-density fiberboards manufactured using Dendrocalamus giganteus (Munro bamboo). The fiber production was carried out through the chemo-thermo-mechanical pulping process with four different conditions. The panels were made with 10% urea formaldehyde resin based on dry weight of the fibers, 2.5% of a catalyzer (ammonium sulfate) and 2% paraffin. The results indicate that treatments with the highest alkali (NaOH) percentage, time and splinter heating temperature improved the physical properties of the panels. The root-fiber interface was evaluated through scanning electron microscopy in fracture zones, which revealed fibers with thick, inflexible walls. The panels' mechanical properties were affected due to the fiber wall characteristics and interaction with resin. Giant bamboo fiber has potential for MDF production, but other studies should be carried out.

Xylanase and beta-Xylosidase from Penicillium janczewskii: Production, Physico-chemical Properties, and Application of the Crude Extract to Pulp Biobleaching

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Seed germination performances of Styrax species help understand their distribution in Cerrado areas in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Qualidade da madeira e da celulose de clones de Eucalyptus spp. de diferentes densidades

Pós-graduação em Ciência Florestal - FCA

Impacto da adição de caulim nas propriedades físico-mecânicas do papel formado por sequências ECF

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito de reagentes de branqueamento na classificação e refinação de polpa de eucalipto

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of colloidal silica on the mechanical properties of fiber-cement reinforced with cellulosic fibers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência da lignina residual no estágio final de branqueamento com peróxido de hidrogênio

Dentre os reagentes alternativos, têm-se destacado o peróxido de hidrogênio, visando atender às demandas de produção de celulose ECF. Reagentes como cloro e dióxido de cloro reagem com a lignina residual, levando à formação de compostos organoclorados, fator negativo para as questões relacionadas ao meio ambiente. O fator kappa (FK) é determinante para a dosagem de dióxido de cloro em seqüencias de branqueamento que determinarão a alvura requerida e reduzirão a formação de compostos organoclorados no licor residual. O presente estudo avaliará o efeito da lignina residual através do número de permanganato, após o estágio D1, no branqueamento com peróxido de hidrogênio. Foram realizados cinco branqueamentos de polpas iguais por seqüências ECF em ensaios laboratoriais, variando-se o fator kappa entre eles. O branqueamento foi realizado com uma polpa kraft de eucalipto, prédeslignificada com oxigênio, utilizando a quantidade de reagentes requeridas para cada estágio, em sacos de polietileno e mantidas em banho de vapor com controle de temperatura pelo tempo requerido. A seqüência D(E+P)DP proposta foi comparada com a seqüência D(E+P)DD. Os métodos utilizados para realizar este estudo são os de procedimento padrão conforme as normas TAPPI e CPPA para branqueamento em laboratório de polpa celulósica. Foram avaliados os parâmetros de qualidade da polpa branqueada com os valores de alvura, viscosidade, número kappa, número de permanganato, reversão de alvura e custo do processo de branqueamento e a influência do fator kappa sobre cada uma das condições propostas. Os resultados foram interpretados com base para as polpas que atingiram a alvura objetivo de 90 %ISO. Verificou-se que o FK ideal obtido foi de 0,20 para as seqüências avaliadas. A lignina residual afetou negativamente o branqueamento de todas as sequências, sendo a sequência D(E+P)DP com FK de 0,20 e carga ...

Proposta de aproveitamento de resíduos de uma indústria moveleira para produção de chapas de revestimento decorativo

Industrial activity is growing at an increasingly rapid accelerated bringing impacts not very consistent with the preservation of the environment, since it uses its resources to meet its countless demands, making the sources begin to become increasingly scarce. Therefore, this paper proposes the use of waste a furniture industry for the production of panels for the interior decoration. Were used to manufacture them, two different types of materials, where such, the Kraft paper is more efficient for the underpinnings of these panels. Regarding the type of glue used, the contact yielded better results. The initial conditions for the development of such a proposal were based on existing laws for solid waste as well as proposals for environmental agencies

Durabilidade da argamassa mista de revestimento interno contendo dregs-grits em substituição à areia

This paper concerns about the durability of new material in construction. It is noteworthy the fact that increases increasingly searching for alternative materials that do not depend only of natural resources and at the same time be an alternative for reuse of industrial waste. Since the construction materials have a long life and a high cost of civil works and maintenance, it is crucial to estimate the behavior of a new product. Thus , this work discuss the durability of mixed mortar lining , made with waste from the process Kraft pulp production , known as dregs and grits , in partial replacement of sand. Tests were conducted to simulate conditions as adverse environments of constant heat and fire, with the aim of analyzing the behavior of mortar mixed matched the behavior of standard mortar

Otimização da extração alcalina com peróxido de hidrogênio em seqüência de branqueamento com aplicação de baixo fator kappa

The new market, focused on sustainability and other environmental concerns, refers to innovations that seek alternative forms of production. In pulp and paper bleaching alternative reagents are studied, for example, hydrogen peroxide, in partial substitution of chlorine dioxide in order to reduce the formation of organochlorines. In this context, this study examined the burden of hydrogen peroxide (H2O2) on alkaline extraction stage (stage Ep) required for the bleaching of pulp with eucalyptus kraft pulp, pre-oxygen delignified to obtain equivalent brightness at 90 ± 0.5% ISO, as well as its effect on quality of pulp produced. The pulp was bleached by the sequence D(Ep)DP, with the application of factor kappa of 0.14 and varying the concentration of hydrogen peroxide in Ep stage three, five, seven and nine kilograms of reagent per ton of pulp absolutely drought. The final P stage was optimized with the use of six, nine and twelve pounds of hydrogen peroxide per ton of absolutely dry pulp to achieve the required brightness. The quality of the pulp produced was analyzed based on the kappa number, the brightness and the viscosity. The methods were performed according to standards set by the standard TAPPI (Technical Association of the Pulp and Paper Industry). The best result was obtained using the following D0Ep(7)D1P(6), which showed a viscosity of 19.9 cP, 89.6% ISO brightness, consumption of 94.9 kg / t of reagents and reagent costs of US$ 28.15, because it showed better pulp quality for a lower cost compared to the others. It was found that the greater the amount of hydrogen peroxide in alkaline extraction, the lower the kappa number and increased the amount of residual hydrogen peroxide. The higher the charge of hydrogen peroxide in Ep stage, the lower the need for hydrogen peroxide in the final P stage, reducing the cost of bleaching

Concreto autoadensável utilizando cinza de casca de arroz: estudo das propriedades mecânicas

Pós-graduação em Engenharia Civil - FEIS

Viabilidade de sementes de Handroanthus heptaphyllus (Vell.) Mattos armazenadas nos frutos

Pós-graduação em Ciência Florestal - FCA